JPS6131747A - Speed control method for automatic transmission of vehicle - Google Patents

Abstract

PURPOSE:To prevent the occurrence of speed change shock by carrying out temporarily speed change through forward speed change stages other than the first speed when vehicle speed and throttle opening are less than predetermined values and a shift lever is shifted between the reverse range and drive range. CONSTITUTION:When vehicle speed is judged to be zero and throttle judged to be fully closed and when shifts of N-D, R-D, D-R, etc. are carried out, a transmission carries out temporarily the speed change through the forward speed change stage other than the first speed. Thus, since output shaft torque will be smoothly converted from positive to negative and vice versa, speed change shock caused by back lash present in a drive system can be prevented.

Description

[Detailed description of the invention] [Industrial application field]

The present invention relates to a shift control method for an automatic transmission for a vehicle, and particularly during a so-called D-R shift or R-D shift.
The present invention relates to a shift control method for an automatic transmission for a vehicle that is improved so as to prevent the generation of impact noise in the drive system.

[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 that is operated by the driver, a vehicle speed sensor that de-freezes the vehicle, and a throttle sensor that detects the throttle opening. Accordingly, the joint state of the FIi friction joint device can be automatically switched at least in relation to the vehicle speed. 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. It is known that the transmission is made to go through a gear stage other than the first gear, which has a small ratio, to prevent the occurrence of shock due to sudden transmission of torque. In addition, we have further improved this shift control by engaging one clutch and one brake in advance when the shift lever is in the N (neutral) position so that gear ratios other than 1st gear can be engaged smoothly. It is already known that the combination of
-78845>.

[Problems to be solved by the invention] However, for example, when parking in a garage or turning around on a narrow road, a shift is performed directly from R (reverse) to D (drive) or from D to R. In such cases, there is a problem in that the conventional shift control does not work. That is, when such an R-D shift or a D-R shift is performed, the output shaft torque is reversed from negative to positive or from positive to negative. , those that have the problem of so-called rattling noise (impact noise) occurring due to backlash that exists in drive systems such as spline joints in friction joint devices or gear joints in differential devices. It is. , [Object of the Invention] The present invention has been made in view of the above-mentioned conventional problems, and is an object of the present invention when an operation in which the output shaft torque is reversed, such as an R-D shift or a D-R shift, is performed. An object of the present invention is to provide a speed change control method for an automatic transmission for a vehicle that can prevent the generation of impact noise due to backlash existing in a drive system.

[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 automatically adjusted at least in relation to vehicle speed and throttle opening according to the range selected with the shift lever. Switch to
In a shift control method for a vehicle automatic transmission that achieves one of a plurality of gears, as shown in FIG. 1, it is detected whether the vehicle speed and throttle opening are below predetermined values. A procedure for temporarily shifting forward gears other than first gear when the vehicle speed and throttle opening are below predetermined values and the driver shifts the shift lever between the reverse range and the drive range. The above objective is achieved by including a procedure for passing the . Further, in an embodiment of the present invention, when temporarily passing through a forward gear other than the first gear, the gear is first temporarily passed through the first gear, so that the shift control described above can be carried out smoothly. Short @ in the dark (it was made to take place).

[Operation] In the present invention, when the driver shifts the shift lever between the reverse range and the drive range, the output shaft torque is temporarily passed through a forward gear other than the first gear. The positive/negative reversal of is made gentler, and the impact noise of the drive system can be reduced. In addition, for this shift control, the vehicle speed and throttle opening are detected, and the shift control is performed only when the vehicle speed and throttle opening are below a predetermined value, making the 978 hour control safe and effective. It can be done smoothly. Embodiments Hereinafter, embodiments of the present invention will be described in detail 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 10, 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 10 includes a pump 16 and a turbine 1.
8 and a stator 20. The pump 16 is connected to the engine crank shaft 22, and is connected to the turbine 1.
8 is connected to the turbine shaft 24. The turbine shaft 24 is the output shaft of the torque converter 10, 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 an overdrive clutch Co and a one-way clutch Fo are provided between the sun gear 30 and a housing 32 surrounding the overdrive mechanism 12. A brake Bo is provided. The ring gear 34 of the overdrive mechanism 12 is connected to the input shaft 36 of the underdrive mechanism 14,
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 side planetary tooth IJ device includes a sun gear 42 provided on a sun gear shaft 40 common to the front side and the rear side, and the sun gear 42
A carrier 46 rotatably supports the planetary pinion 44, and a ring gear 48 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 40. 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 idler gear device is connected to a ring gear 54 in the rear planetary gear 'IA position, and these carrier 46 and ring gear 54 are connected to an output shaft 56. Also, the carrier 52 and the housing 3 in the rear planetary gear device
2, a fast and reverse brake B3 and a one-way clutch F2 are provided. Further, a second brake B2 is provided between the sun gear shaft 40 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. ing. This automatic transmission is equipped with 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 EG, a vehicle speed sensor 102 that detects vehicle speed, etc. The electromagnetic solenoid valve S in the hydraulic control circuit 106 is activated by the processing device 104 in response to the freezing pattern.
1, S2, and S3 are driven and controlled, and the combinations of engagement of each clutch, brake, etc. as shown in Table 1 are performed to perform speed change control. Table 1 Here, ◯ indicates that each clutch and brake are in an engaged state or a locked state, and × indicates that they are in an open state or an operating state such as overrun. The solenoid valves 81 and 82 control the speed change from the first speed to the fourth speed, and the electromagnetic solenoid valve S3
is provided in parallel with the torque converter 10, and the pump 1
A lock-up clutch 108 for mechanically connecting the turbine 6 and the turbine 18 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. Next, the operation of this first embodiment will be explained with reference to the flowchart shown in FIG. First, when the engine EG is started, the process proceeds to step 210, where the 7 lag F of each shift determination of N-D, R-D, and D-R is reset, and then, the process proceeds to step 220, where the timer T counts. The value Tc is reset to zero. Then,
The process proceeds to step 230, and in the main routine, four forward gears including overdrive are determined according to the vehicle speed and throttle opening, and the process proceeds to step 240. If no shift such as N-DlR-D%D-R is made, a NO determination is made in step 240, and a NO determination is made in both steps 250, 260, and 270, so step 380 is performed. In step 230, a gear shift is performed according to the gear position determined in step 230. When any one of N-D, R-DSD-R, etc. is performed, one of steps 250, 260, and 270 is performed.
Since it is determined that the answer is YES, the process proceeds to step 280, where flag F is set to 1, and at step 290, timer T starts counting. As a result, the determination in step 240 becomes YES, and in step 300 it is determined whether the brake is ON, in step 310 it is determined whether the vehicle speed is zero, and in step 320 it is determined whether the throttle is fully open. If all of these three determinations are YES, shift control according to the present invention is performed. That is, first, in step 330, it is determined whether the value Tc counted by the timer T is smaller than a preset value T. If it is determined that the count value Tc is smaller than T1, the process proceeds to step 370, where a 1st speed gear position instruction is issued, and the appropriate solenoid is driven at step 380. Thereafter, when the count value Tc becomes larger than T1, the process proceeds to step 340, and it is determined whether or not the count value Tc is larger than a predetermined value T2 (T2>TI>.The count value Tc is smaller than T2. Since the determination at step 340 is NO, the process proceeds to step 350, where a gear other than 1st gear is instructed, and step 380
The corresponding solenoid is actuated. Eventually, when the count value Tc becomes larger than T2, the process proceeds from step 340 to step 360, where both the flag F and the count value Tc are set to zero, and at step 370, the 1st gear position is again instructed, and at step 380, the process proceeds to step 360. A corresponding solenoid drive is provided. From step 380, again step 23
0, so this series of procedures continues until the engine is turned off, and the above shift control is performed no matter how many times N-D, R-DSD-R, etc. shifts are performed. There is. In addition, in steps 300, 310, and 320, if any one of the brake ON, vehicle speed zero, and throttle fully open is N
When the determination is O, the process proceeds to step 390, where the count value Tc of the flag F1 timer T is both set to zero, and the process proceeds to step 370, so that the shift control described above is not performed. When the vehicle speed is determined to be zero (specifically, for example, if the vehicle speed is 9
The reason why shift control is not performed other than when the vehicle speed is 1an/hr or less is that it may be undesirable if a gear other than 1st gear is instructed when the vehicle speed is not zero. Also, the shift control is not performed except when the throttle is fully open (specifically, it is determined that the throttle is fully closed when it is close to fully open). This is because if this is done, not only will there be a problem in terms of the durability of the friction coupling devices such as the clutches and brakes mentioned above, but it is also thought that the impact noise and shock may become louder. Note that the conditions related to the brake are provided to confirm double conditions, and are not necessarily essential conditions in the present invention as long as both the conditions of zero vehicle speed and fully open throttle are satisfied. Furthermore, in the above embodiment, when temporarily passing through a forward gear other than the first gear, the gear is first temporarily passed through the first gear (until the count value Tc of the timer T reaches T1). The reason for this is as follows. That is, R-
If, for example, an instruction to go through 3rd gear is issued from the beginning when a shift such as D is performed, as is clear from Table 1 above, in 3rd gear not only the forward clutch C1 but also the second brake will be activated. B2, direct clutch C2
It becomes necessary to operate a total of three servo mechanisms at the same time. As a result, a large amount of oil needs to be supplied at the same time, so R-
A problem arises in that the time lag until the shift such as D is completed becomes long. Therefore, in the above embodiment, an instruction to shift to 1st gear is first issued, the forward clutch C1 is stroked to a certain extent, and then the servo mechanisms other than 1st gear are operated. By doing so, the time lag of R-D etc. can be shortened as a result. FIG. 4 shows a diagram showing the relationship between oil pressure and output shaft torque along the time axis. The figure shows the situation when the RD shift is performed. As shown in Table 1 above, when the shift lever is in the R range, the direct clutch C2 and the first and reverse brake B3 are in the connecting state, so hydraulic pressure for operating them is supplied. Here, when the R-D shift is performed, first gear is instructed until T1, so the hydraulic pressure of direct clutch C2 and first and reverse brake B3 is released, and the forward clutch C1 is Hydraulic pressure begins to be supplied. After passing T1, an instruction to go through 3rd gear is issued, so the first and reverse brake B3 loses its oil pressure, and the oil pressure for operating the direct clutch C2 begins to rise again. The oil pressure of the second brake B2 begins to rise. Meanwhile, the oil pressure for operating the forward clutch C1 continues to rise. After passing T2, the first gear is instructed again, so the oil pressure to the direct clutch C2 and second brake B2 is released, and only the forward clutch C1 continues to rise, and finally only the forward clutch C1 is engaged. Hydraulic supply is provided. The output shaft torque has been improved from the conventional broken line X to the solid line Y, and the impact noise that conventionally occurred at point P on the broken line X has been almost eliminated. In the above embodiment, in order to shorten the time lag until the end of the shift, a procedure was adopted in which the transmission is first made through the first gear when passing through a forward gear other than the first gear, but the present invention In this case, this first step via the first speed is not necessarily required. (Effects of the Invention) As explained above, according to the present invention, the driver can
When -D, [)-R shift operations are performed, the output shaft torque can be smoothly reversed from negative to positive or from positive to negative, reducing impact noise caused by backlash existing in the drive system. You can get excellent results.

[Brief explanation of drawings]

FIG. 1 is a flowchart showing the taste composition of the present invention, and FIG.
FIG. 3 is a schematic layered block diagram of a vehicle automatic transmission equipped with a torque converter in which an embodiment of the method of the present invention is adopted, and FIG. 3 is a flowchart showing the control processing procedure used in the above embodiment.
FIG. 4 is a diagram showing the relationship between oil pressure and output shaft torque along the time axis when the above embodiment is used.

Claims (2)

[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 according to the range selected with the shift lever, at least the vehicle speed and the throttle opening Relatedly, in a speed change control method for an automatic transmission for a vehicle, which automatically switches the joint state of a friction joint device to achieve any one of a plurality of gears, the vehicle speed and throttle opening are below a predetermined value. The procedure for detecting whether or not the A method for controlling a shift in an automatic transmission for a vehicle, comprising: a step of passing through a forward gear other than the first gear; (2) The automatic transmission for a vehicle according to claim 1, characterized in that when temporarily passing through a forward gear other than the first gear, the gear is first temporarily passed through the first gear. Machine speed control method.