JPH068664B2 - Shift control device for automatic transmission - Google Patents

Description

Detailed Description of the Invention

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a shift control device for an automatic transmission, and more particularly, to a shift control device capable of automatically and independently shifting gears.
A transmission and a second transmission, wherein the first transmission and the second transmission
The present invention relates to an improvement of a shift control device for an automatic transmission that achieves a multi-speed shift by shifting the gearbox simultaneously or alternately.

[Prior art]

With the rapid spread of automatic transmissions for vehicles in recent years, firstly, with the intention of improving fuel economy, the first transmission that can automatically change the gear stage in relation to the vehicle speed, throttle opening, etc. A so-called overdrive device having a ratio of 1 or less, which is additionally provided in series as a second transmission, has been widely used. Further, paying attention to the function of the second transmission capable of switching between the low speed stage and the high speed stage such as the overdrive device, this is actively synchronized with the shift of the first transmission, and the first transmission and the second transmission It is already known that the transmission and the transmission are shifted simultaneously or alternately to achieve a multistage shift of 6 forward speeds by performing shift control as shown in part A of FIG. 4, for example. (JP-A-57-3714)
No. 0). In this way, by arranging the first transmission and the second transmission in a serial relationship, the existing automatic transmission is used as a basis, and multistage shifting can be easily realized while reducing design changes and being advantageous in manufacturing. Therefore, it is possible to obtain many advantages such as an improvement in fuel consumption, an improvement in power performance, and a reduction in the load on the friction material due to the multiple shift stages.

[Problems to be Solved by the Invention]

However, in the case of an automatic transmission in which such a first transmission and a second transmission are simultaneously or alternately shifted to achieve a multi-speed shift, for example, from the second speed of FIG. By shifting the first transmission to a high gear and shifting the second transmission to a low gear, such as shifting to the third speed and shifting from the fourth speed to the fifth speed, the entire automatic transmission is changed. In some cases, an upshift may occur, but at this time, if each shift is simply controlled individually, an increase in gear shift cannot be avoided, and for example, an upshift after a downshift or a downshift after an upshift. There is a problem that the gear shifting characteristics may have a strange driving feeling.

[Object of the Invention]

The present invention has been made in view of such a conventional problem, and upshifts the entire automatic transmission by shifting the first transmission to a high gear and the second transmission to a low gear. Even in such a case, it is an object of the present invention to provide a gear shift control device for an automatic transmission, which has less gear shift shock and can obtain a favorable upshift gear shift feeling.

[Means for solving problems]

The present invention is provided with a first transmission and a second transmission that are capable of automatically and independently switching gears, and by shifting the first transmission and the second transmission simultaneously or alternately. In a shift control device for an automatic transmission that achieves multi-speed shift, when the first automatic transmission is shifted to a high gear and the second transmission is shifted to a low gear, the automatic transmission is shifted up. , The first
The above-mentioned object is achieved by providing a control means for starting and completing the change of the rotational speed of the member of the second transmission to the low gear shift while the speed of the transmission member is changing to the high gear shift. It was done.

[Action]

In the present invention, while the member of the first transmission is performing the rotation speed change for the high gear shift, the rotation speed change of the member of the second transmission is started to the low gear shift,
And because it was decided to complete, the gear shift is small,
In addition, the driver can be given a good sense of upshift.

【Example】

Embodiments of the present invention will be described in detail below with reference to the drawings. FIG. 3 shows an overall outline of an automatic transmission for a vehicle to which the present invention is applied. This automatic transmission includes a torque converter 20 as a transmission portion thereof, an auxiliary transmission 40, and a main transmission 60 having three forward gears and one reverse gear. The torque converter 20 includes a pump 21 and a turbine 2.
2, a stator 23, and a lockup clutch 24. The pump 21 is connected to the crankshaft 10 of the engine 1, and the turbine 22 is connected to the carrier 41 of the planetary gear unit in the auxiliary transmission 40. In the sub transmission 40, the planetary pinion 42 rotatably supported by the carrier 41 meshes with the sun gear 43 and the ring gear 44. A clutch C ₀ and a one-way clutch F ₀ are provided between the sun gear 43 and the carrier 41, and a brake B ₀ is provided between the sun gear 43 and the housing Hu. The main transmission 60 is provided with two rows of front and rear sides as a planetary gear device. This planetary gear device has a common sun gear 61 and ring gears 62, 6 respectively.
3, planetary pinions 64 and 65, and carrier 6
It consists of 6, 67. The ring gear 44 of the sub transmission 40 is connected to the ring gear 62 via the clutch C ₁ . A clutch C ₂ is provided between the ring gear 44 and the sun gear 61. Further, the carrier 66 is connected to the ring gear 63, and the carrier 66 and the ring gear 63 are connected to the output shaft 70. On the other hand, the brake B is provided between the carrier 67 and the housing Hu.
₃ and the one-way clutch F ₂ are provided, and a brake B ₂ is provided between the sun gear 61 and the housing Hu via the one-way clutch F ₁ and the sun gear 61 and the housing Hu are connected to each other. A brake B ₁ is provided between them. This automatic transmission is provided with the transmission section as described above, and inputs signals from the throttle sensor 100 for detecting the throttle opening that reflects the load state of the engine 1 and the vehicle speed sensor 102 for detecting the vehicle speed. The central processing unit (ECU) 104 thus driven drives and controls the electromagnetic solenoid valves S _{1 to} S ₄ in the hydraulic control circuit 106 according to a preset shift pattern, as shown in part B of FIG. As described above, the shift control is performed by combining the engagements of the clutches, the brakes, and the like. In FIG. 4, the mark ◯ indicates the engaged state, and the mark x indicates the engaged state only when the engine brake is used. The electromagnetic solenoid valves S ₁ and S ₂ are connected to the main transmission 60.
Of the electromagnetic solenoid valve S ₃
The auxiliary transmission 60 controls the high speed side and the low speed side, and the electromagnetic solenoid valve S ₄ controls the lockup clutch 24 of the torque converter 20, respectively. In FIG. 3, reference numeral 110 is a shift position sensor that detects the positions of N, D, R, etc. operated by the driver, and 112 is a pattern select switch, which is E (economical travel), P. (Power running) or the like is selected, 114 is a water temperature sensor for detecting the cooling water temperature of the engine, 116 is a foot brake, and 118 is a foot brake.
Indicate brake switches for detecting the operation of the side brakes. Here, in this embodiment, the central processing unit 10
In addition to these input signals, the pressure for detecting the oil pressure of the oil passage toward the brake B ₂ to be described later in order to recognize the start of the change in the rotation speed of each member of the main transmission 60 accompanying the gear shift command. The signal from the switch 120 is also input. FIG. 5 shows a main part of the hydraulic control circuit 106. In the figure, reference numeral 200 is a first shift valve for switching the main transmission 60 between the first speed state and the second speed state,
S ₁ is an electromagnetic solenoid valve for controlling switching of the first shift valve, 300 is a high speed side of the auxiliary transmission 40,
A third shift valve for switching the low speed side, S ₃ is an electromagnetic solenoid valve for controlling the switching of the third shift valve 300, and 400, 500 and 600 are the brakes B ₂ , B ₀ and clutch C, respectively. Reference numeral 700 denotes an accumulator for controlling the transient characteristic of hydraulic pressure in the oil passage to _0, and reference numeral 700 denotes a manual valve interlocked with a shift lever operated by the driver. The configuration and operation of each of these devices are basically the same as the conventional ones, and thus detailed description of each device is omitted. Reference numeral 800 is a release control valve for controlling the time and operating pressure when the action of the brake B ₀ is released by controlling the drain hydraulic pressure of the third shift valve 300. The release control valve 800 has different face areas A ₁ , A ₂ (A ₁
<A ₂ ), two lands 802 and 804 are provided, and the drain hydraulic pressure of the brake B ₀ is input to a port 806 provided at an intermediate position between the two lands 802 and 804, and
A slott pressure from a slottlet valve (not shown) is input to a port 810 provided on the lower side of the land 804 having a large facet area in the figure. The above-mentioned pressure switch 120 is provided in the oil passage to the brake B ₂ . The pressure switch 120 operates when the hydraulic pressure P _B2 of the oil passage to the brake B ₂ reaches a predetermined pressure P _B2 ′ at which the member of the main transmission 60 starts changing its rotational speed (depending on the throttle opening degree). ), And is set to output an ON signal to the ECU 104. Next, the operation of this embodiment will be described with reference to FIGS. 1 and 2. When the main transmission 60 shifts to a high gear and the sub transmission 40 shifts to a low gear and upshifts as a whole of the automatic transmission, as is clear from FIG. 4, the shift from the second speed to the third speed is performed. shift,
Also, there is a shift from the fourth speed to the fifth speed, but the purpose is exactly the same, so here, the shift from the second speed to the third speed will be described as an example. First, in step 900, the vehicle speed, throttle opening,
Alternatively, based on the signal from the pattern select switch,
The shift determination (shift determination from the second speed to the third speed) is performed by the same operation as the conventional one. When this determination is made, after a grace period of time T ₁ predetermined according to the throttle opening degree is set in step 902, the main transmission 6
The electromagnetic solenoid valve S ₁ is turned on in order to switch the first shift valve 200 that controls 0 (step 9).
04). The grace of the time T ₁ is provided so that only the last judgment made when two or more speed changes are judged in a short time is extracted. When the electromagnetic solenoid valve S ₁ is turned on, first the piston of the brake B ₂ ends the stroke (point A in FIG. 2), and the inertia phase of the main transmission 60 starts from point B in FIG. 60
The rotation speed of each member begins to change. On the other hand, in the vicinity of point B in FIG. 2, the predetermined pressure P which is predetermined according to the throttle opening degree as the hydraulic pressure of the brake B ₂ increases.
_{When the} pressure switch 120 is activated at _B2 ', the step 9
At 06, the central processing unit 104 recognizes the start of the inertia phase of the main transmission 60 (the period during which the rotation speed of each member is changed). In this case, in order to recognize the inertia phase more accurately, it is recognized that the inertia phase starts at a time point after the pressure switch 120 is actuated and a predetermined time period is set in accordance with the throttle opening. Is even better. When the inertia phase is recognized, a shift command is issued to the electromagnetic solenoid valve S ₃ at step 908 (point D in FIG. 2), and the third shift valve 300
, The hydraulic pressure of the brake B ₀ is drained, and the low gear shift of the auxiliary transmission 40 is started (D ′ in FIG. 2).
point). The drain characteristic of the brake B _{0 at} this time is the auxiliary transmission 40.
The low gear shift of FIG. 2B to FIG. 2F (inertia phase of the main transmission 60) is completed, and the check attached to the accumulator 500 keeps the output shaft torque level I of the auxiliary transmission 40 as high as possible. Orifice with valve 502,
It is adjusted by the release control valve 800 and an orifice 814 provided on the input port side of the release control valve 800. That is, when the hydraulic pressure of the brake B ₀ is drained, the return speed of the accumulator 500 is suppressed by the action of the check valve-equipped orifice 502. Therefore, in the release control valve 800, the brake B ₀ is released.
Of the drain oil pressure P _B0 of the port 810 and the predetermined pressure P determined by the force of the spring 812.
When it is more than _B0 ', it becomes the state on the left side of the figure and port 80
6 and the port 808 are short-circuited to rapidly drain the hydraulic pressure of the brake B ₀ , and when the hydraulic pressure of the brake B ₀ is equal to or lower than the predetermined pressure P _B0 ′, the state on the right side of the drawing is reached. 808 is closed, and after that, Olifis 814
The oil pressure of the brake B ₀ or the oil of the accumulator 500 is gently drained through the. On the other hand, the main transmission 60 that started the inertia phase from point B
By the action of the accumulator 400, the hydraulic pressure rises to Yutsukuri and brake B _2, as shown into N _S diagram of FIG. 2 (rotation diagram of the sun gear 61), Inashiya phase in point F completes To do. Since the clutch C ₀ does not require synchronous engagement with the brake B ₀ due to the existence of the one-way clutch F _0, a large piston stroke of the clutch C ₀ is used to delay the engagement timing to reduce gear shift shock. is doing. As a result, the drain characteristic of B ₀ as described above causes the second
As shown in the _NT diagram (output axis diagram of the turbine 22) of the figure, the auxiliary transmission 40 always starts shifting after the main transmission 60 enters the inertia phase, and is at the point E, that is, the main transmission. The rotational speed change is completed while the transmission 60 is still in the inertia phase. As described above, in the above-described embodiment, the hydraulic pressure of the brake B ₀ is drained after the start of the inertia phase of the main transmission 60 is detected, and the drain characteristic is rapidly changed up to a predetermined pressure P _B0 ′. Since the characteristic is such that the constant pressure corresponding to the throttle opening degree is maintained for a predetermined time after the decrease, the sub transmission 40 is properly operated at any throttle opening degree after the main transmission 60 starts to change the rotation speed. It will start shifting. In addition, as shown in the output shaft torque diagram of FIG. 2 (A) (each diagram is a characteristic when each is shifted independently), the main transmission 60 and the engine 1 are prevented from being disconnected and the sub-shift is performed. It is possible to gradually shift the gear while maintaining the torque transmission of the predetermined I in the machine 40. Therefore, as shown in FIG. 2B, the gear shift shock can be further reduced. It should be noted that in the above-described embodiment, the configuration and the operation when the shift from the second speed stage to the third speed stage has been described, but the present invention has exactly the same purpose as the fourth speed stage to the fifth speed stage.
It goes without saying that it can be applied to the shift to the speed stage. Further, in the above embodiment, as a means for detecting the inertia phase of the main transmission, the pressure switch 120 which is turned on when the hydraulic pressure P _B2 of the brake B ₂ reaches a predetermined pressure P _B2 ′.
However, the main transmission 6 according to the present invention is used.
The means for detecting the inertia phase of 0 is not limited to this. For example, the oil pressure of the brake B ₂ may be continuously detected by an oil pressure sensor, or the electromagnetic solenoid valve S ₁ may be turned on. Alternatively, it may be detected by a timer (determined according to the throttle opening degree) with reference to the time of shift determination. Further, the change in the rotation speed of the engine 1 or each member of the automatic transmission may be directly detected.

【The invention's effect】

As described above, according to the present invention, the first transmission shifts to the high gear and the second transmission shifts to the low gear,
When performing an upshift as the entire automatic transmission, it is possible to reduce shift shock and prevent a strange driving feeling such as a downshift after the upshift or an upshift after the downshift. Excellent effect can be obtained.

[Brief description of drawings]

FIG. 1 is a flow chart showing an embodiment of a shift control device for an automatic transmission according to the present invention, and FIGS. 2 (A) and 2 (B) are diagrams showing a shift transient characteristic in the embodiment, and FIG. Is an overall schematic view of an automatic transmission for a vehicle to which the embodiment is applied,
FIG. 5 is a diagram showing an engagement state of each friction engagement device of the automatic transmission, and FIG. 5 is a circuit diagram showing a main part of a hydraulic control circuit of the automatic transmission. B _0, B 2 _... Brake, C 0 _... clutch, _S 1 to S 4 _... electromagnetic solenoid valve, 40 ... sub-transmission, 60 ... main transmission, 120 ... pressure switch, 200 ... first shift valve, 300 ... first 3 shift valves, 400, 500, 600 ... Akyumulator, 502 ... Orifice with check valve, 800 ... Release control valve, 814 ... Orifice.

Claims (1)

[Claims] 1. A first transmission and a second transmission, which are capable of automatically and independently switching a shift stage, and the first transmission.
A shift control device for an automatic transmission, wherein a multistage shift is achieved by shifting a transmission and a second transmission simultaneously or alternately, wherein the first transmission is shifted to a high gear, and the second transmission is changed. Due to the low gear shift, when the entire automatic transmission is upshifted, the second gear is changed while the member of the first transmission is changing the rotation speed to the high gear shift.
A shift control device for an automatic transmission, comprising control means for starting and completing a change in the number of revolutions of a member of the transmission to a low gear shift.