JPS59212562A - Method of detecting optimum speed change stage of automatic transmission gear - Google Patents

Abstract

PURPOSE:To prevent the wear of operating equipments and improve the driving feeling by moving the down-shift characteristics of shift-map to the lower vehicle- speed side from the up-shift characteristics and making its inclination steeper than that of said up-shift characteristics. CONSTITUTION:A shift-down line Sd1 is moved in parallel toward the lower speed side from the shift-up line Sup, and a shift-down line Sd2 is inclined deeper toward the low vehicle-speed side and the accelerator pedal depressing side, resulting in its inclination being made steeper than that of the shift-up line Sup. Thereby, hysteresis can exist in both up shift and down shift, eliminating the repetition f unnecessary up and down shifting. Thereby, the wear of operating equipments can be prevented while good driving feeling can be obtained.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a method for detecting an optimum gear position for an automatic transmission.

1. A parallel gear shaft type transmission is automatically shifted by operating a clutch actuator, select and shift actuators using an electronic control device. The control method for the gear shifting surface in this type of automatic transmission, for which an automatic transmission has been proposed, is to use a vehicle speed signal (pulse) from the vehicle speed sensor, and a signal (voltage) corresponding to the accelerator pedal depression from the accelerator pedal sensor. And the select signal (matrix signal) from the select lever is input to the electronic 1j control circuit, and the control signal output from this electronic control circuit causes the clutch to be disengaged → the car to be in the middle☆- state → select → shift shift → This is done by operating each of the actuators in the order of successive crunches.

In this case, the shift map translated by the select lever has an amplifier shift map and a downshift map determined by the amount of depression of the accelerator pedal and the vehicle speed, and the gear shift is performed according to this map. By the way, this map may be formed so that the upshift and downshift characteristics are only slightly separated or completely overlapped, or the downshift is simply shifted parallel to the upshift to the lower vehicle speed side. It is formed in such a way that it is nothing more than As a result, up and down shifts are repeated near the shift line in response to slight variations in vehicle speed or the amount of depression of the accelerator pedal, which leads to wear and tear on the operating equipment and is also unfavorable in terms of driving feeling.

The present invention was created in view of these points,
The purpose of this is to provide hysteresis for upshifts and downshifts to avoid unnecessary repetition of upshifts and downshifts, thereby preventing unnecessary wear and tear on operating equipment and providing a good driving feel. An object of the present invention is to provide a method for detecting the optimum gear position of a transmission.

Next, an embodiment of the optimum gear position detection method for an automatic transmission according to the present invention will be described in detail with reference to the drawings.

Figure 1 shows the hydraulic control circuit for gear shift operation.
In the figure, 10 is a select actuator, 20 is a shift actuator, 30 is a clutch actuator,
■1 to V4 are on-off valves, 75 to 7 are flow path switching valves, P is a pump, T is a tank, and 1 to 5. R and N indicate the gear position, ON-OFF indicates the engagement and disengagement of the flank, and SL is a select lever for yellowing the shift map. The select and shift actuators 10 and 20 are configured to be able to stop at three positions, and are arranged to engage the step cylinders 13 and 23, the first pistons 11 and 21, and the first piston and the second piston. It consists of cylindrical second pistons 12 and 22 that fit together, and the rods lla and 21a of the first piston
is engaged with an internal lever of the transmission (not shown).

Both the actuators 10 and 20 have both chambers 13a, 13b and 23 of their older cylinders 13 and 23, respectively.
When hydraulic pressure is applied to chambers 13a and 23b, the first pistons 11 and 21 are in the neutral state shown in the figure, and when hydraulic pressure is applied to chambers 13a and 23a, the first pistons 11 and 21 move to the right in the figure together with the second pistons 12 and 22. , and when hydraulic pressure is applied to each chamber 13b and 23b, the first screw!
・Ns 11 and 21 move independently to the left in the figure.

Chambers 13a and 13 of the select actuator 10
b communicates with pump P (via on-off valve v1) or tank T via flow path switching valves v5 and V6, respectively.

Chambers 23a and 23b of the shift actuator 20
are communicated with the pump P (via the on-off valve v1) or the tank T via the flow path switching valves V7 and V, respectively.

The clutch actuator 30 includes a cylinder 33 and a piston 31 . It consists of a piston rod 31a that is connected at one end to the piston 31 and at the other end to an operating lever of a clutch (not shown), and the chamber 33a is connected to a pump P (via an on-off valve V□) via an on-off valve V2. It also communicates with the tank T via the on-off valve v5 and the pulse-controlled on-off valve 4. Note that the chamber 33b is piped so as to always communicate with the tank T side.

Reference numeral 50 denotes an electronic control device composed of a microcomputer, which includes a position sensor 01 for detecting the operating position of the clutch actuator 30, an accelerator pedal depression amount -02 for detecting the operating position of the accelerator pedal, and a vehicle speed sensor 0.
3. Based on the input signals from the engine rotation sensor 04, the engine coolant temperature sensor 05, the gear position sensor 06 that detects the gear position of the transmission, the select signal from the selector train/<-3L, etc., the opening/closing valve is V1~
4 and the select lever SL that controls the flow path switching valves V5 to Ve has switch switches S1 to S6 that generate a select lever signal for detecting the position of the lever, and the signal is sent to the electronic control device 50. Input, switch 81~S5
L1 to L5. with a combination of one each of groups S and I to S6. It is configured so that each position of D, HD, R, and H is represented, and each position L1 to L3, D.
A shift map corresponding to... is built into the electronic control circuit 50.

Figure 2 shows a shift map with hysteresis.
In the figure, a, al~a, 1i accelerator pedal depression amount, V, V,~■4 is vehicle speed, Sup is shift up line,
Sd, . . . Sd2 are downshift lines, and A-H are positions on the shift map to indicate the operation.

The downshift line Sd1 is a slightly parallel shift of the amplifier shift line Sup toward the low vehicle speed side, and the downshift line Sd2 is a shift up line S that is deep toward the low vehicle speed side and the accelerator pedal depression side.
A downshift line is provided that has a steeper slope than the upshift line.

In an automatic transmission using such a shift map,
Driving with the accelerator pedal pressed down, the vehicle speed is vl
(Km/h), the transmission shifts up to 4th gear. When the vehicle is traveling at vehicle speed V2, if the accelerator pedal depression amount is relaxed from al to a2, the vehicle speed decreases from ■2 to v3. However, since the line i does not cross the downshift line Sd2, no downshift operation occurs. If you press the accelerator pedal to A4 at vehicle speed V3, it will shift down to 3rd gear, but it will not shift down to A3 halfway.

If you press down to a7□ and shift to 3rd gear, shift up to 4th gear at vehicle speed ■41.

If the downshift line is the same as Sup, just slightly moving the accelerator (including vibration) at A will shift up or shift down. Also, the shift down line is
In the case of d, an upshift and a shift down are performed simply by depressing the accelerator pedal from a2 to al within the range of vehicle speeds v1 and v3.

As explained in detail above, the present invention manually inputs signals from the jljl medium speed sensor, accelerator pedal sensor, and left lever to an electronic control circuit, and selects /\- by the control signal from the electronic control circuit. In an automatic transmission that automatically selects a gear position according to the determined shift map characteristics, the downshift characteristics of the shift map characteristics are set to the lower vehicle speed side than the amp shift characteristics, that is, the side where the accelerator pedal depression is deeper, and the downshift characteristics are set to the upshift side. By making the slope of the characteristics on the town shift side steeper than the characteristics of This will prevent unnecessary wear and tear and provide a good driving feeling.

[Brief explanation of the drawing]

FIG. 1 is a hydraulic circuit diagram for operating the transmission, and FIG. 2 is a shift map. 10... Select actuator, 20... Shift actuator unique, 30... Clutch actuator,
50...Electronic control device, SL...Select lever,
02...Accelerator pedal sensor, 03...Vehicle speed sensor, Sup...Upshift line, Sd2...Downshift line

Claims (1)

[Claims] Automatic shifting that inputs signals from the vehicle speed sensor, accelerator pedal sensor, and select lever to an electronic control circuit, and automatically selects the transmission according to the characteristics of the shift map determined by the Sereno I lever using the control signals from the electronic control circuit. An optimal gear position detection method for an automatic transmission, characterized in that the downshift characteristic of the shift map characteristic is moved to a lower vehicle speed side than the upshift characteristic, and is made steeper than the gradient of the upshift characteristic.