JPS6239294B2 - - Google Patents

Description

[Detailed description of the invention] The present invention relates to a method of controlling an automatic transmission for a vehicle.

It has a plurality of frictional engagement devices that are engaged when hydraulic pressure is supplied, and by changing the combination of engagement of the frictional engagement devices, it is possible to move between a plurality of speed stages including a plurality of forward speed stages. A gear transmission mechanism to be switched, a manual shift valve that selectively determines a range of forward speed stages that are allowed to be set by being switched between a plurality of switching ranges including a plurality of forward ranges, and a manual shift valve that can be set by the manual shift valve. An automatic transmission for a vehicle, comprising: a control device that sets the gear transmission mechanism to one of the forward speed stages based on a plurality of input signals including signals related to vehicle speed and throttle opening within a range of allowed forward speed stages. have been proposed in various configurations. The switching ranges of the manual shift valve in this type of automatic transmission for vehicles are generally the P range selected when parking the vehicle, the R range selected when reversing the vehicle, and the gear transmission mechanism in the idle state. N range to be set, selected under normal driving conditions, and based on multiple input signals including signals related to vehicle speed and throttle opening, all forward speed gears from 1st gear to the highest speed gear of 4th gear, for example. The D range allows setting of the highest speed gear, for example, 4th gear, but other gears between 1st and 3rd gears are set based on multiple input signals including signals related to vehicle speed and throttle opening. It has 3 ranges, which allows setting to any speed stage, and in 2nd and 3rd gears, allows the automatic transmission to reversely drive from the output shaft side to the input shaft side, and activates the engine brake. Regardless of a plurality of input signals including signals related to throttle opening, the gear transmission mechanism is set only to the first speed gear, and at the same time, in particular, at the first speed gear, the automatic transmission is moved from the output shaft side to the input shaft side. This is known as the L range, which allows reverse driving and activates engine braking.

In this type of automatic transmission, when the vehicle is started with the manual shift valve currently switched to, for example, the D range, the first
When the gear transmission mechanism is sequentially switched from the speed stage to the 2nd speed stage, the 3rd speed stage, and the 4th speed stage, there is generally no need for engine braking to act in the 1st speed in the D range. Therefore, the first rotary element to be braked in order to achieve the first gear in the gear transmission mechanism is braked by a one-way clutch. In this case, when the gear transmission is switched to the second speed due to an increase in vehicle speed, the second rotary element to be braked in the gear transmission to achieve the second speed is braked. , since the first rotating element begins to rotate in the direction in which the one-way clutch slips, there is no need to use any synchronizing means to switch the braking between the first rotating element and the second rotating element.
The shift from the first speed stage to the second speed stage is performed smoothly.

However, when the manual shift valve is switched to the L range, in order to operate the engine brake, the first rotary element is subjected to a braking action by a hydraulic brake arranged in parallel with the one-way clutch. The rotation of the first rotating element is actively braked in any direction of rotation. Assume that the manual shift valve is switched to the 3rd range or the D range while the vehicle is being driven in the L range. At this time, if the operating condition of the vehicle at that time is such that it should be operated in the second gear based on conditions such as vehicle speed and throttle opening, then the control device in the automatic transmission After determining this, braking of the second rotating element is started to immediately switch the gear transmission mechanism to the second speed stage.
However, in this case, in order to achieve the second speed stage,
First, the hydraulic brake actively braking the first rotating element must be released and the first rotating element must be released to rotate freely. Therefore, in this case, if the brake on the second rotary element begins to act before the hydraulic brake on the first rotary element is sufficiently released, the gear transmission mechanism will be temporarily locked. , and the output shaft torque becomes negative. Furthermore, when the first rotational element is released, the engine speed is reduced to correspond to the second speed, so a positive output shaft torque is generated due to engine inertia, causing a knocking sound and a shift shock.

In recent years, with the development of electronic computing technology, various proposals have been made for using electronic computing units to perform judgment functions in the operation of automatic transmissions for vehicles of this type. In automatic transmissions for vehicles that incorporate this type of electronic calculation device, driving is generally performed with emphasis on vehicle speed, throttle opening, manual shift valve switching position (shift position), output performance, and fuel efficiency. Based on the switching position of the pattern select switch, which selects the driving pattern such as whether to perform driving with emphasis on performance, and other input signals, the electronic processing unit automatically changes gears at every moment at a cycle of several milliseconds. Determine the speed stage to which the machine should be set, operate the solenoid valve based on that determination,
The supply of hydraulic pressure to each frictional engagement device is controlled. If the present invention as described above is implemented in such an electronically controlled automatic transmission for a vehicle,
As mentioned above, for example, by switching the manual shift valve from the first speed stage under the L range, a changeover to the second speed stage under the 3rd range occurs, and therefore the frictional engagement to be released. If an undesirable interference occurs between the operation of the frictional engagement device and the frictional engagement device to be engaged, the occurrence of such a situation will be detected during the control calculation performed by the electronic circuit, and the engagement will be prevented. What is necessary is to incorporate a calculation process that allows hydraulic pressure to be discharged from the frictional engagement device that is to be released, but delays the supply of hydraulic pressure to the frictional engagement device that is to be newly engaged for a predetermined period of time.

By the way, in this type of automatic transmission for vehicles, the function of supplying hydraulic pressure to the friction engagement device that applies the engine brake in the 3rd range or the L range is generally performed by a manual shift valve. For example, regarding the first speed stage,
Electrical calculation device is L range 1st speed, 3rd range 1st
The system is configured to give the same hydraulic output to both D-range and 1st speed, and the manual shift valve supplies hydraulic pressure to the friction engagement device that applies the engine brake at the 1st speed. This is done through a port that is mechanically opened when the switch is switched to the L range. Focusing on this point, when the manual shift valve is switched from one of the forward ranges to the other one of the forward ranges according to the present invention, from the moment of said switching, the friction coefficient to be released by said switching is Allowing the hydraulic pressure to be discharged from the friction engagement device, but blocking the supply of hydraulic pressure to the friction engagement device to be newly engaged until a predetermined period of time has elapsed from the moment when the hydraulic pressure is discharged from the friction engagement device, means that the gear shift is stopped until the predetermined period of time has elapsed. It is convenient to use an electronic arithmetic unit for gear change to perform control such that the previously set speed gear is maintained. In this way, if the manual shift valve is switched to a shift range in which engine braking does not apply at that speed while the speed gear is held at the previously set speed, the engine brake will not be applied until then in order to apply engine brake. Naturally, the hydraulic pressure that was being supplied to the frictional engagement device that was engaged begins to be discharged immediately, and on the other hand, no new hydraulic pressure is supplied to any of the frictional engagement devices, so the speed that should be set next It is also possible to delay the supply of hydraulic pressure to the frictional engagement device which should be newly supplied with hydraulic pressure in order to achieve the stage.

The present invention addresses the above-mentioned problems when changing gears occurs by switching a manual shift valve, and in particular, solves the problem of a plurality of frictional gears being engaged when hydraulic pressure is supplied. A gear transmission mechanism having a friction engagement device and switching between a plurality of gear stages including a plurality of forward speed stages by changing the combination of engagement of the friction engagement device, and a plurality of switching stages including a plurality of forward ranges. A hydraulic pressure for selectively determining a range of forward speed stages that are allowed to be set by switching between ranges, and for operating an engine brake on one of the frictional engagement devices when switching to one forward range. and a manual shift valve that releases the supply of hydraulic pressure for operating an engine brake to the one friction engagement device when the forward range is switched to another forward range wider than the one forward range; The plurality of gear transmission mechanisms are configured to set the gear transmission mechanism to one of the forward speed stages based on a plurality of input signals including signals relating to vehicle speed and throttle opening within a range determined according to the switching position of the manual shift valve. In the automatic transmission for a vehicle, the manual shift valve is switched from the one forward range to the other forward range. In order to provide an automatic transmission for a vehicle that is improved in relation to the above problem, the control device is operated in the one forward range until a predetermined time has elapsed from the moment of said switching. It provides a method for controlling machines.

The invention will now be described in detail by way of example embodiments with reference to the accompanying drawings.

FIG. 1 is a schematic diagram showing the configuration of an apparatus for carrying out the method of controlling an automatic transmission for a vehicle according to the present invention. FIG. 1 schematically shows the configuration of an automatic transmission controlled by the control method of the present invention. This automatic transmission 1 is known per se, and includes an input shaft 2 connected to an output shaft of an engine (not shown), a hydraulic torque converter 3, and an input signal that bypasses the torque converter 3. A direct coupling clutch 4 connects the shaft 2 directly to the output shaft 3a of the torque converter, and a shaft 5 connected to the output shaft 3a of the torque converter is used as an input shaft, which is given several speed change characteristics and whose output shaft 6 drives the vehicle. It includes a gear transmission mechanism 7 that outputs driving force for driving the wheels.

The gear transmission mechanism 7 is provided with a carrier 8 connected to the input shaft 5, a planetary pinion 9 supported by the carrier, a sun gear 10 and a ring gear 11 meshing with the planetary pinion, and between the carrier 8 and the sun gear 10. a one-way clutch (F ₀ ) 12, a clutch (C ₀ ) 13 that selectively connects the carrier 8 and the sun gear 10, and a sun gear 1.
₀ to the housing.

The gear transmission mechanism 7 further includes a clutch (C ₁ ) 17 and a clutch (C ₂ ) 18 that selectively connect the intermediate shaft 15 and the sun gear shaft 16 to the ring gear 11, a ring gear 19 connected to the intermediate shaft 15, and a sun gear shaft 16. Sun gear 20 and ring gear 19 connected to
A planetary pinion 22 carried by a carrier 21 meshed between and a sun gear 20 and connected to the output shaft 6, a sun gear 23 connected to the sun gear shaft 16, and a ring gear 2 connected to the output shaft 6.
4. A planetary pinion 25 meshed between the sun gear 23 and the ring gear 24, a carrier 26 supporting the planetary pinion, and a sun gear shaft 16.
a brake (B ₁ ) 27 for selectively fixing the sun gear shaft to the housing via a one-way clutch (F ₁ ) 28; a brake (B ₂ ) 29 for selectively fixing the sun gear shaft to the housing via a one-way clutch (F 1 ) 28; On the other hand, a one-way clutch (F ₂ ) 30 fixes the carrier 26 against rotation in one direction, and a brake (B ₃ ) 3 fixes the carrier 26 selectively to the housing.
1, and includes a transmission device that achieves three forward speeds and one reverse speed.

The direct coupling clutch 4 in the automatic transmission 1 and the clutch and brake in the gear transmission mechanism 7 are selectively supplied with hydraulic pressure by the automatic transmission hydraulic control device 32, or the supplied hydraulic pressure is discharged. This allows the direct coupling clutch to be selectively engaged or released, and to be set between four forward gears, including overdrive, and one reverse gear. . The automatic transmission hydraulic control device 32 is controlled by three solenoids. Of these, the solenoid
The two No. 1 and No. 2 are for controlling the gear transmission mechanism 7, and the gear transmission mechanism that is switched between four forward speeds and one reverse speed, including overdrive, by these two solenoids is the subject of the present invention. This was proposed in Japanese Patent Application No. 55-69110 filed by the same applicant. Solenoid No. 3 is for controlling the direct coupling clutch 4 between engagement and release.

When the automatic transmission hydraulic control device is controlled by a solenoid in this way, it can be controlled by a so-called computer 33, and the vehicle speed,
Based on a large number of information signals representing vehicle operating conditions such as throttle opening, manual shift range, gear position, vehicle running altitude, and engine temperature, the operating conditions that provide the vehicle's optimal operating condition are calculated, and based on that, the automatic The transmission can be controlled.

Figure 2 shows the automatic transmission shown in Figure 1.
2 is a table showing the energization and de-energization of solenoids and the engagement states of friction engagement elements such as clutches and brakes and one-way clutches at each gear stage achieved under various manual shift ranges.
In this list, manual shift range D,
3.L, R, P, and N indicate D range, 3rd range, L range, reverse range, parking, and neutral, respectively, and gears 1st, 2nd, 3rd, O/D,
Rev indicates the first, second, third, overdrive, and reverse gear positions, respectively. Additionally, in this list, for a solenoid, an O mark indicates that it is energized, an X mark indicates that it is de-energized, and an * mark indicates that the direct coupling clutch is engaged. Indicates that it is energized at the right time. Furthermore, in the same table, frictional engagement elements are engaged only when marked with a circle, and are disengaged at other locations. Similarly, with respect to one-way clutches, these are engaged only when the engine is running at the locations marked with a triangle, and are released at other locations.

As can be understood from Fig. 2, when the automatic transmission shown in Fig. 1 is operated in the D range or the 3rd range, the vehicle speed increases from the state in which it was operated in the 1st gear. When switching to the second speed stage _is performed by
From the state in which hydraulic pressure was being supplied to C ₁ , hydraulic pressure is further supplied to brake B ₂ or both brakes B ₁ and B ₂ in addition to these frictional engagement elements. Therefore, in this case, switching from the first speed stage to the second speed stage is simply a matter of newly supplying hydraulic pressure to the friction engagement element to which no hydraulic pressure was previously supplied. Even if the supply timing of the hydraulic pressure to be supplied is not taken into account, if the hydraulic pressure is supplied with a certain degree of smoothness, no shocking fluctuations will occur in either the engine torque or the axle torque.

However, suppose that the vehicle is currently being driven with the manual shift valve set to L range, and then the manual shift valve is switched to D range or 3 range. If the operating state of the vehicle at this time is an operating state corresponding to the second gear, the control computer 33 instructs the automatic transmission hydraulic control device 32 to shift the gear to the second gear the moment it detects the switching of the manual shift valve. command to switch to high speed. At this time, if the supply of hydraulic pressure to brake B ₂ or brakes B ₁ and B ₂ is started immediately, brake _{B 2 or} brakes B ₁ and The supply of hydraulic pressure to B ₂ is started, and the two brakes that should be released and the brakes that should be engaged are simultaneously engaged, resulting in a state in which the gear transmission mechanism is temporarily locked. , the output shaft torque becomes negative, and after the brake _B3 is released, the engine speed rapidly decreases to correspond to the second speed, and at this time, positive torque is generated on the output shaft due to engine inertia energy.
This state is shown in FIG. 3A, B, and C.

FIG. 4 is a flowchart showing one embodiment of a method for controlling an automatic transmission for a vehicle according to the present invention. Starting from the start, when input values such as vehicle speed, throttle opening, shift position, etc. are read, it is determined whether the shift position is in the L range, 3 range, or D range.
When the shift position is in the L range, control in the L range is immediately performed. In the case of the automatic transmission shown in FIGS. 1 and 2, in the L range, the gear transmission mechanism is normally held fixed at the first speed stage in a state where engine braking can be applied.

If the shift position is in the 3rd range, the 3rd
A determination is made whether the range has been shifted from the L range. When the 3rd range is shifted from the L range, a time count is started. The L range control is performed in the electronic arithmetic unit until the counted time T exceeds a predetermined set time _T1 . When L range control is performed with the manual shift valve switched to the 3rd range, hydraulic pressure begins to be discharged from the brake _B3 .

When the count time T exceeds the set value _T1 , control of three ranges is started. Therefore, when the vehicle is in a state where it should be operated at the second speed stage, the supply of hydraulic pressure to the brakes _B1 and _B2 is started.

Similarly, when switching from L range to D range is performed, L range control is performed from the moment it is detected until a predetermined set time _T2 has elapsed, and only after the set time has elapsed. D range control is performed. This control mode is the same as when switching from L range to 3 range is performed.

When such timing control according to the present invention is performed, the engine rotational speed, output shaft torque, when an upshift from the first speed stage to the second speed stage occurs by switching the manual shift valve from the L range to the 3rd range, The oil pressure in the frictional engagement device is shown in FIGS. 5A, B, and C in contrast to FIG. 3. From a comparison between FIG. 3 and FIG. 5, it will be understood that according to the present invention, a large sudden change in the output shaft torque that occurs during such an upshift can be avoided.

Although the present invention has been described in detail with respect to one embodiment above, the present invention is not limited to this embodiment, and various other embodiments are possible within the scope of the present invention. This will be clear to those skilled in the art.

[Brief explanation of the drawing]

FIG. 1 is a schematic diagram showing an example of a vehicular automatic transmission to which the control method according to the present invention is applied and a control device therefor, and FIG. 2 is a schematic diagram showing the gear stages in the gear transmission mechanism shown in FIG. FIG. 3 is a list showing the energized/deenergized and engaged states of the solenoid, frictional engagement device, and one-way clutch to be achieved, and FIG. 3 shows the control method of the present invention in the automatic transmission for a vehicle shown in FIGS. 1 and 2. Engine rotation speed, output shaft torque, and working oil pressure of the friction engagement device (servo oil pressure) when the gear stage changes from 1st gear to 2nd gear by switching from L range to 3 range when FIG. 4 is a flowchart showing one embodiment of the control method of the present invention, and FIG. If implemented, the engine rotation speed, output shaft torque, and working oil pressure of the friction engagement device ( servo hydraulic)
It is a graph showing the progress of. DESCRIPTION OF SYMBOLS 1... Automatic transmission, 2... Torque converter input shaft, 3... Torque converter, 3a... Torque converter output shaft, 4... Direct connection clutch, 5...
Gear transmission mechanism input shaft, 6... Gear transmission mechanism output shaft, 7... Gear transmission mechanism, 8... Carrier, 9...
... Planetary pinion, 10 ... Sun gear, 11
...Ring gear, 12...One-way clutch,
13...Clutch, 14...Brake, 15...
Intermediate shaft, 16... sun gear shaft, 17, 18... clutch, 19... ring gear, 20... sun gear, 21... carrier, 22... planetary pinion, 23... sun gear, 24... link gear,
25... Planetary pinion, 26... Carrier, 27... Brake, 28... One-way clutch, 29... Brake, 30... One-way clutch, 31... Brake, 32... Automatic transmission hydraulic control device, 33... ...control computer.

Claims (1)

[Claims] 1 A plurality of frictional engagement devices (C ₀ , B _{0 ,} C 1 , C ₂ , B ₁ , B ₂ ,
B ₃ ), and by changing the combination of engagement of the frictional engagement device, multiple forward speed stages (1st, 2nd,
A gear transmission mechanism 7 that can be switched between a plurality of gears including 3rd, O/D) and a plurality of shift ranges including a plurality of forward ranges (L, 3, D) allows setting. selectively determining a range of forward speed stages to be used, and supplying hydraulic pressure for operating an engine brake to one of the frictional engagement devices (B ₃ ) when the forward speed range is switched to one forward range (L); a manual shift valve that releases the supply of hydraulic pressure for operating an engine brake to the one friction engagement device when the one forward range (3, D) is switched to another forward range (3, D) wider than the one forward range; , for setting the gear transmission mechanism to one of the forward speed stages based on a plurality of input signals including signals related to vehicle speed and throttle opening within a range determined according to the switching position of the manual shift valve. A method for controlling an automatic transmission for a vehicle, which includes control devices 32 and 33 that switch and control supply and discharge of hydraulic pressure to a plurality of frictional engagement devices, wherein the manual shift valve changes from the one forward range (L) to the forward range (L). The controller is characterized in that when the switch is made to another forward range (3 or D), the control device is operated in the one forward range (L) until a predetermined time (T ₁ ) has elapsed from the moment of the switch. How to do it.