JPS6145162A - Speed change control method for automatic speed change gear of car - Google Patents

Abstract

PURPOSE:To reduce a speed change shock by keeping a frictional engagement device for the second speed in the engagement state when a car velocity is below a designated value, and a shift lever is in P-range and R-range. CONSTITUTION:An output from a car velocity sensor 102 is input to ECU104, and when a car velocity is below a designated value, and a shift lever is in P- range and R-range, a frictional engagement device B2 for the second speed is kept in the engagement state. Thus, when the lever is shifted to D-range, the same state as that of indication of the second speed is formed to reduce a speed change shock.

Description

[Detailed description of the invention]

[Field of Industrial Application] The present invention relates to a shift control method for an automatic transmission for a vehicle, and in particular, the present invention relates to a shift control method for an automatic transmission for a vehicle, and in particular, the present invention relates to a shift control method for an automatic transmission for a vehicle, and in particular, when the shift lever is
, N (neutral) range to D (drive) range.

[Conventional technology]

The gear transmission mechanism includes a gear transmission mechanism and a plurality of friction coupling devices, and the coupling of the friction coupling devices is selectively switched by operating a hydraulic control device to achieve one of the plurality of gears. Automatic transmissions for vehicles configured to do this are already widely known. Such automatic transmissions for vehicles generally include a shift lever operated by a driver, a vehicle speed sensor that detects vehicle speed, and a throttle sensor that detects throttle opening. The joint state of the Jl friction joint device can be automatically switched in relation to vehicle speed and throttle opening. Conventionally, in the automatic transmission for a vehicle as described above, when the driver performs an N-D shift operation, the gear is temporarily shifted before the planetary gear transmission mechanism of the transmission is brought into the first gear engagement state. There is known a system that performs so-called squat auto control, which prevents the occurrence of shock due to sudden transmission of torque by passing through a gear position other than the first gear, which has a small ratio. In addition, we have further improved this squat auto control and set the shift lever to N (neutral) so that gear ratios other than 1st gear can be smoothly engaged with a short time lag.
There is also already known a device in which one clutch and one brake are engaged in advance from when the vehicle is in position (Japanese Patent Laid-Open No. 55-78845).

[Problems to be solved by the invention]

However, for example, when parking a garage, turning around on a narrow road, or parking, a direct R-D or PD shift may be performed. However, there was a problem in that the conventional scroll auto control did not work. Furthermore, the conventional N-D squat auto control is performed regardless of other situations when an N-D shift is performed, so the above-mentioned squat auto control is performed even when the driver is in a hurry to start, for example. There was a problem in that this caused the vehicle to be unable to take off quickly.

[Purpose of the invention]

The present invention has been made in view of the above-mentioned conventional problems, and it is an object of the present invention to provide a shift control method for an automatic transmission for a vehicle, which can reduce shock even when shifting from R-D to P-D. As the first objective, when the N-D shift is made, it is unconditionally squat auto as before! l! A first object of the present invention is to provide a shift control method for an automatic transmission for a vehicle, which allows a quick start by omitting the squat auto control when the driver is considered to be in a hurry to start. 2 objectives.

[Means to solve the problem]

The present invention includes a shift lever operated by a driver;
Equipped with a vehicle speed sensor that detects vehicle speed and a throttle sensor that detects throttle opening, the joint state of the friction coupling device is selectively switched in relation to at least vehicle speed and throttle opening according to the range of the shift lever. In the shift control method for an automatic transmission for a vehicle, the shift lever is set to P (parking) or R (reverse) when the vehicle speed is below a predetermined value and the shift lever is set to P (parking) or R (reverse). The first object is achieved by maintaining the second speed rfJm coupling device in the coupled state when the vehicle is in each range. The present invention also includes a shift lever operated by a driver, a vehicle speed sensor that detects the vehicle speed, and a throttle sensor that detects the throttle opening. In a shift control method for an automatic transmission for a vehicle, in which one of a plurality of gears is achieved by selectively switching the coupling state of a friction coupling device, the vehicle speed and the throttle opening are controlled. is below a predetermined value, and the shift lever is N(
The second object is achieved by maintaining the second speed friction coupling device in the engaged state when the vehicle is in the neutral range. An embodiment of the present invention achieves the above first and second objectives by maintaining the joint state of the second speed A friction joint device for a predetermined time even after shifting to the D range in each of the above inventions. This has been achieved more reliably.

[Effect]

In the present invention, when the shift lever is in each range of PlR, the second speed friction coupling device is maintained in the engaged state, so that when the P-D shift and the R-D shift In other words, the shift is made through a forward gear other than the first gear (second gear), so that the shock at the time of shifting can be reduced accordingly. In addition, since the friction coupling device that is engaged and maintained in each range of PIN is a second continuous friction coupling device, and it is made to be engaged and maintained only when the vehicle speed is below a predetermined value, P,
Not only can the engaged state be maintained without any problem in each R range, but it is also possible to prevent a situation in which the shock is increased by temporarily passing through a forward gear other than the first gear. On the other hand, when in the N range, the second continuous friction coupling device is engaged only when the vehicle speed and throttle opening are below a predetermined value, so the same effect as above occurs even when the shift lever is in the N range. In addition, when the driver is considered to be in a hurry to start, that is, when the throttle opening is above a predetermined value, the second continuous friction coupling device can be maintained in a non-coupled state, and the driver can quickly start the vehicle. A normal first gear start can be performed.

【Example】

Embodiments of the present invention will be described in detail below based on the drawings. FIG. 2 is a schematic block diagram showing an example of a hydraulic four-speed automatic transmission with an overdrive device. This automatic transmission includes a torque converter 1o, an overdrive mechanism 12 as its transmission part,
It includes an underdrive mechanism 14 with three forward stages and one reverse stage. The torque converter 1o includes a pump 16, a turbine 1
8 and a stator 20. The pump 16 is connected to an engine crankshaft 22 and is connected to a turbine 18.
is connected to the turbine shaft 24. The turbine shaft 24 is an output shaft of the torque converter 1o, and
It serves as an input shaft of the overdrive mechanism 12, and is connected to a carrier 26 of a planetary gear device in the overdrive mechanism 12. In the overdrive mechanism 12, this carrier 2
planetary binion 2 rotatably supported by 6
8 meshes with the sun gear 30 and ring gear 34. Further, an overdrive clutch Co and a one-way clutch Fo are provided between the sun gear 30 and the carrier 26, and furthermore, an overdrive clutch Co and a one-way clutch Fo are provided between the sun gear 30 and the overdrive [
An overdrive brake So is provided between the housing 32 surrounding the housing 412 and the overdrive brake So. The ring gear 34 of the overdrive mechanism 12 is connected to the input shaft 36 of the underdrive mechanism 14, and a forward clutch C1 is provided between the input shaft 36 and the intermediate shaft 38. The underdrive mechanism 14 is provided with two rows of planetary gears, one on the front side and the other on the rear side. The front planetary gear device rotatably supports a sun gear 42 provided on a sun gear shaft 4o common to the front and rear sides, a planetary pinion 44 that meshes with the sun gear 42, and a planetary pinion 44 that meshes with the sun gear 42. It is composed of a carrier 46 and a ring gear 48 that meshes with the planetary pinion 44. In addition, the rear planetary gear device is
It is composed of a planetary pinion 50 that meshes with the sun gear 42, a carrier 52 that rotatably supports the planetary pinion 50, and a ring gear 54 that meshes with the planetary pinion 50. A direct clutch C2 is provided between the input shaft 36 and the sun gear shaft 4o. Further, a ring gear 48 in the front planetary gear device is connected to the intermediate shaft 38. Further, the carrier 46 in the front planetary gear device is connected to a ring gear 54 in the rear planetary gear device, and the carrier 46 and ring gear 54 are connected to an output shaft 56. Also, the carrier 52 and the housing 32 in the rear planetary gear device
A fast-and-reverse brake B3 and a one-way clutch F2 are provided between the two. Further, a second brake B2 is provided between the sun gear shaft 4o and the housing 32 via a one-way clutch F1, and a second coast brake B1 is provided between the sun gear shaft 40 and the housing 32. There is. This automatic transmission includes a transmission section as described above, and receives signals from a throttle sensor 100 that detects the throttle opening that reflects the load condition of the engine E/G, a vehicle speed sensor 102 that detects vehicle speed, etc. The central processing unit 104 drives and controls the electromagnetic solenoid valves S1, 82 and S3 in the hydraulic control circuit 106 according to a preset shift pattern, and performs the combination of engagement of each clutch, brake, etc., and performs shift control. is to be done. The electromagnetic solenoid valves S1 and S2 control the first to fourth speeds, and the electromagnetic solenoid valve S3 is provided in parallel with the torque converter 10 to mechanically connect the pump 16 and the turbine 18. The lock-up clutch 108 for connection is controlled. In addition, the reference numeral 110 in FIG. 2 is a shift position sensor that detects the positions of N, D, R, etc. operated by the driver, and the reference numeral 112 is a pattern select switch.
(Economy driving) and P (Power driving).
Further, 114 indicates a water temperature sensor that detects the engine cooling water temperature, 116 indicates a foot brake, and 118 indicates a brake switch that detects the operation of the handbrake. FIG. 3 shows the main parts of the hydraulic control circuit 106. In the figure, reference numeral 111 is a manual valve linked to a shift lever operated by the driver, 120 is a 1-2 shift valve for controlling the second brake B 2 and the first and reverse brake B3, and 130 is a manual valve linked to a shift lever operated by the driver;
1 indicates a 2-3 shift valve for controlling the forward clutch C1 and the direct clutch C2, 160 indicates a low coast modulator valve, and 170 indicates a second coast modulator valve, respectively. Hydraulic pressure pressurized by an oil pump (not shown) is regulated to line pressure by a primary regulator valve (not shown), and is supplied to the oil path 1 . The manual valve 111 switches hydraulic pressure between N, D, R, etc. in conjunction with a shift lever operated by a driver. Line pressure is supplied to the boat 111A of the manual valve 111, and the other boats 111B to 111E are supplied to the boat 111A of the manual valve 111.
When the hydraulic control circuit 1 is in the position shown in the figure where it is not in communication with
06 is in the N range. Also, boats 111A and 1
If 11B is not connected, D range, boats 111A and 11
If 1B and 111C communicate, it will be in the second gear range, if boats 111A and 111B to 111D communicate, it will be in L range, if boats 111A and 111E are not in communication, it will be in R range, and if boat 111A is closed by spool 111F, it will be in P range. It is set to be a range. 1-2 shift valve 120 is an electromagnetic solenoid valve S
Controlled by 2. When the electromagnetic solenoid valve S2 is in the OFF state and no hydraulic pressure is applied to the boat 1201, the 1-2 shift valve 120 is in the state on the right side of the drawing. On the other hand, either the electromagnetic solenoid valve $2 is in the off state and hydraulic pressure is operating in the boat 120I, or the electromagnetic solenoid valve S2 is in the on state +137-
If so, the -91-2 shift valve 120 is in the state on the left side of the drawing. 2-3 shift valve 130 is an electromagnetic solenoid valve S
1. If the electromagnetic solenoid valve S1 is in the OFF state and the oil pressure is not operating in the boat 130J, the 2-3 shift valve 130 is in the state on the right side of the drawing. On the other hand, the electromagnetic solenoid valve S1 is in the off state,
If the boat 130J is hydraulically operated or the electromagnetic solenoid valve S1 is in the on state, the 2-3 shift valve 130 is in the state on the left side of the drawing. The line pressure is independent of the position of the manual valve 111.
It is supplied to the boat 12oD of the 1-2 shift valve 120. Also, since it is also supplied to electromagnetic solenoid valve $2, SL, N, R. The 1-2 shift valve 120 and the 2-3 shift valve 130 can be controlled in each range of P. Therefore, in each of the N, R, and P ranges, if the electromagnetic solenoid valve S2 is in the on state (because no oil pressure is applied to the boat 120I), the 1-2 shift valve 120
is in the state on the left side of the drawing, boat 120D and boat 1
20E, and the second brake B2 becomes in a joint state. As shown in FIG. 2, the second brake B2 has a one-way latch F1 arranged in parallel with it, so that
Even if the second brake B2 is engaged in the N range, there is no problem because the one-way clutch F1 idles. In this automatic transmission, a hydraulic control circuit having the above-described configuration performs automatic gear shift control by combining the couplings of clutches, brakes, etc. as shown in FIG. 4. Next, the operation of the above embodiment will be explained according to the flowchart shown in FIG. When the engine is started, the process proceeds to step 210, and in the main routine, the gear position is determined based on the vehicle speed and throttle opening. Next, in step 220 it is determined whether the vehicle speed is zero, and in step 230 it is determined whether the brake is on. If either one is determined as No, the process advances to step 290, and the gear position determined in the main routine is executed by the solenoid drive control routine. If the vehicle speed is zero and it is determined that the brake is on,
Proceeding to step 240, it is determined whether the range is P range or N range. If it is in either the P range or the N range, the process proceeds to step 250, and by turning on the electromagnetic solenoid valve S2, the 1-2 shift valve 120 in FIG. 3 is controlled and the second brake B2 is applied. , hydraulic pressure is supplied to the second brake B2
is joined. If it is determined in step 240 that it is neither the P range nor the N range, the process proceeds to step 260, where it is determined whether or not the N range is present. If it is determined that the vehicle is not in the N range, the process advances to step 290, and the gear position determined in the main routine 210 is executed. When it is determined in step 260 that the vehicle is in the N range, the process proceeds to step 270, where it is determined whether the throttle opening is fully open (specifically, when it approaches fully open, it is determined that the throttle opening is fully open). When it is determined that the throttle opening is fully open, the process proceeds to step 250, where the electromagnetic solenoid valve S2 is turned on to engage the second brake B2. If it is determined that the throttle opening is not fully open, the process proceeds to step 280, where the electromagnetic solenoid valve $2 is turned off, and the gear position determined in the main routine is executed at step 290 with the second brake B2 released. Ru. In this manner, when the throttle opening is equal to or greater than the predetermined value, the second brake B2 is released, so that deterioration of starting performance in the case of N-D shift is prevented. FIG. 5 shows a second embodiment of the present invention. The figure shows a flowchart of a control procedure for releasing the second brake B2 after a certain set time after the N-D shift. That is, the first
Even in the control shown in the flowchart shown in the figure, since the second brake B2 is already in the engaged state when it is in the P and N ranges, the P
, when the N range is shifted to the D range, or when the N-D shift is performed when the throttle is fully closed, a substantial second gear instruction is instantaneously issued, so the output shaft torque Although the effect of eliminating the sudden change can be obtained, in this embodiment, the second gear instruction state is more actively created to further ensure the above effect. When the engine is started, first, in step 300, the count value T of the N-D shift determination flag flag timer T is
c are both reset to zero. Then step 310
In the main routine, the gear position is determined based on the vehicle speed and throttle opening. Thereafter, the process proceeds to step 320, where it is determined whether the flag F is 1, that is, whether an ND shift has been performed. When it is determined that the N-D shift is not performed, it is determined in step 330 whether the vehicle speed is zero, and in step 340 it is determined whether the brake is on. If the determination is YES, the process advances to step 350, where it is determined whether the range is P range or R range. When this determination is YES, the electromagnetic valve S2 is turned on in step 360, and the step 310 is turned on in step 370.
The gear position determined in is executed. On the other hand, when it is determined in step 350 that the P range or the R range is not the R range, the process proceeds to Step 380, where it is determined whether the P range or the R range is the N range. When in the N range, the process proceeds to step 390, where it is determined whether the throttle opening is fully open. When it is determined that the brake is not fully open, the electromagnetic solenoid valve S2 is turned off in step 400, and the second brake B2 is released to stand by so that good starting performance can be obtained when the N-0 shift is performed. When it is determined that the throttle opening is fully open, step 410
In step 1, it is determined whether or not an ND shift has been performed. When an ND shift has been performed, a flag is set to 1 in step 420, and a count Tc of timer T is started in step 430. Note that when it is determined that the shift is not an N-D shift, the electromagnetic solenoid valve S2 is turned on in step 440, and the second brake B2 is placed in the connecting state. Since step 370 returns to step 310 again, after the N-D shift, step 320
In step 450, flag F is determined to be 1, and the process proceeds to step 450. In step 450, it is determined whether the count value To of the timer T is greater than or equal to the set value, and the count value Tc
is less than the set value, the electromagnetic solenoid valve S2 remains on in step 460, and the count value Tc
becomes larger than the set value T1, step 470
The solenoid valve S2 is turned off in step 4.
At 80, the 7lag F and the count value Tc of the timer T are reset to zero. By operating in this way, T after N-D shift
The automatic transmission is reliably instructed to the second gear within one hour, and returns to the first gear instruction after the elapse of time T1. As a result, sudden changes in output shaft torque are more accurately suppressed, and shift shocks are prevented. Furthermore, shift shock can be reduced even when an R-D or PD shift is performed. Also, as a means of doing so, 1. The friction coupling device for 2nd gear is engaged in advance, rather than issuing a shift instruction for gears other than 1st gear when shifted to the D range. As shown in the comparison, it is possible to make the time lag and control execution time extremely small. Furthermore, considering that the shift shock has been reduced, if the diameter of the orifice of the forward clutch C1 is increased accordingly, the time required to reach the engaged state of the first gear when shifted to the D range can be reduced. It is also possible to shorten it further. In addition, in the present invention, the reason why the vehicle speed is required to be below a predetermined value is because if an instruction other than 1st gear is issued when the vehicle speed is high, the shift shock may be increased instead. . In addition, in the above embodiment, whether or not the brake is on is also considered, but this is for confirmation.
This is not necessarily an essential requirement in the present invention.

【Effect of the invention】

As explained above, according to the present invention, since the friction coupling device for the second speed is connected in each of the P and R ranges, when shifting to the D range, the same state as the second speed instruction occurs. is formed, so an excellent effect of reducing the shift shock can be obtained. In addition, since the second gear friction coupling device is conditionally engaged when the vehicle is in the N range, control for reducing shift shock can always be carried out smoothly and only when necessary. There is also the effect that when the driver is in a hurry to start the vehicle, priority can be given to the driver.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing a processing procedure for speed change control according to a first embodiment of the present invention, and FIG. 2 is a block diagram including a skeleton diagram showing an automatic transmission for a vehicle in which the above embodiment is adopted. FIG. 3 is a circuit diagram showing the main parts of the hydraulic control circuit,
FIG. 4 is a diagram showing the joint/combination state of the friction joint device and electromagnetic solenoid pulp, FIG. 5 is a flowchart corresponding to FIG. 1 showing the second embodiment of the present invention, and FIG. (A)
(B) shows the relationship between the oil pressure and the output shaft torque in the second embodiment along the time axis, and (A) shows the relationship between the oil pressure and the output shaft torque in the second embodiment, and (A) shows the relationship between the oil pressure and the output shaft torque in the second embodiment. The one that outputs the signal (B) is the 2nd speed I! ! Each of the figures shows what the friction joint device connects. 100...Throttle sensor, 102...Vehicle speed sensor, B2...Second brake (friction joint device for 2nd speed).

Claims (4)

[Claims] (1) Equipped with a shift lever operated by the driver, a vehicle speed sensor that detects the vehicle speed, and a throttle sensor that detects the throttle opening, and depending on the range of the shift lever, at least the vehicle speed and the throttle opening Relatedly, in a shift control method for an automatic transmission for a vehicle, in which the coupling state of a friction coupling device is selectively switched to achieve one of a plurality of gears, when the vehicle speed is below a predetermined value, and the shift lever is at P(
1. A shift control method for an automatic transmission for a vehicle, characterized in that a second speed friction coupling device is maintained in an engaged state when the vehicle is in each of the parking range and R (reverse) range. (2) The joint state of the second speed friction joint device is set to P, R.
2. The method of controlling a shift of an automatic transmission for a vehicle according to claim 1, wherein the shift is maintained for a predetermined time even after the shift from each range to the D (drive) range. (3) Equipped with a shift lever operated by the driver, a vehicle speed sensor that detects the vehicle speed, and a throttle sensor that detects the throttle opening, and according to the range of the shift lever, at least the vehicle speed and the throttle opening In a speed change control method for an automatic transmission for a vehicle, in which one of a plurality of gears is operated by selectively switching the joint state of a friction joint device, the vehicle speed and the throttle opening are controlled. is below a predetermined value and the shift lever is in the N (neutral) range, the second speed friction coupling device is maintained in the engaged state. Method. (4) The vehicular automatic according to claim 3, wherein the joint state of the second speed friction joint device is maintained for a predetermined period of time even after being shifted from the N range to the D range. A method of controlling the speed change of a transmission.