JP2615881B2 - Transmission control device for automatic transmission - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial applications]

The present invention relates to a shift control for an automatic transmission, and more particularly to a shift control device for an automatic transmission configured to reduce a shift shock when switching from an N range (neutral range) to a travel range (forward and reverse ranges). Regarding improvement.

[Prior art]

Japanese Patent Laying-Open No. 58-160658 discloses an electronically controlled automatic transmission in which an N-> D shift (shift from a neutral range to a drive range) is reduced.
A technique (square control) for temporarily passing through a gear other than the first gear (lowest gear) is disclosed. Japanese Patent Application Laid-Open No. 61-31747 also discloses that a gear other than the first gear is temporarily passed through in order to reduce a shock during an R → D shift (shift from a reverse range to a forward range). It discloses a square control technology. Note that R
→ D shift is the shortest holding time in the N range R →
This can be regarded as an N → D shift. This square control achieves a gear other than the first gear so that the gear becomes a gear other than the first gear for a predetermined time (for example, about 0.8 seconds) after the N → D shift. Issue a command to engage a friction engagement device for
Thereafter, a command for achieving the first speed is issued. For example, with reference to the engagement chart shown in Figure 4, when it is N → D shift, would otherwise, but only shifts in engaging the clutch C ₁ is to complete, this case, first clutch C ₁ and temporarily form a second gear out of engagement command for the brake B _2, is then to perform the operation of returning the first speed stage by opening the brake B _2. As a result, the shock at the time of the N → D shift can be reduced by the amount by which the gear ratio does not suddenly change, so that the so-called square phenomenon in which the tail portion of the vehicle sinks can be reduced. Conventionally, the speed to be passed is usually the second speed. This is because the third gear has a slightly larger shock reduction effect, but it is not so different.
On the other hand, when the speed to be passed is the third speed, the number of operation servos is large (in the example of FIG. 4, C ₁ , C ₂ ,
Three B _2), cause a decrease in the line pressure, because fear has been made that the shift time lag increases.

[Problems to be solved by the invention]

However, in the case of a vehicle in which the backlash of the drive system is relatively large, the R → D shift or the D
→ There is a tendency that the sound and shock accompanying rattling during the R shift are increased. In this case, for example, by passing through the second speed stage at the time of the R → D shift, the effect of countermeasures against the square phenomenon is small. However, when the vehicle goes through the third speed, the vehicle goes through the third speed, for example, during a normal N → D shift (or D → N → D shift) without reversal of torque. However, there is a problem that the shift time lag may be long as described above.

[Object of the invention]

The present invention has been made in view of such a conventional problem, and always performs a square control properly, even if the vehicle has a relatively large play in the drive system,
It is an object of the present invention to provide a shift control device for an automatic transmission that can reduce a shock at the time of shifting from N to the travel range.

As shown in FIG. 1, the present invention includes means for detecting a shift range. When the shift range is switched from an N range to a forward range or a reverse range. An automatic transmission configured to temporarily engage a friction engagement device for attaining a gear other than the lowest gear to reduce a shock when switching from the N range to the forward range or the reverse range. The shift from the N range to the forward range or the reverse range is performed by shifting the forward range from the forward range to the reverse range via the N range, or from the reverse range to the forward range via the N range. Means for detecting whether or not the shift is one of the second shift, and the shift from the N range to the forward range or the reverse range is the shift of the first shift or the second shift. Means for changing the type of the speed stage to be achieved temporarily between when the shift is performed and when the shift is performed other than the first and second shifts. Is achieved.

[Action]

In the present invention, it is detected whether or not the shift of the N → travel range is a shift in which the torque is reversed. Whether or not the shift is such that the torque is reversed is determined by the relationship between the shift position before the N range and the shift position after the N range. Specifically, when shifting from the forward range → N range → reverse range (first shift) and when shifting from the reverse range → N range → forward range (second shift)
Corresponds to the reverse shift of the torque. D for forward range
Each range includes (drive), 2 (second), L (low), and the like. On the other hand, a shift from forward range → N range → forward range, reverse range → N range → reverse range is a shift without torque reversal. In the present invention, the shift of the N → running range is a shift in which the torque is inverted (first shift or second shift), and a shift in which the torque is not inverted (shifts other than the first and second shifts). The transmission gear stage changes depending on whether or not the vehicle is traveling. Thus, for example, when a shift from N to a running range in which the torque is not reversed is executed, the vehicle is passed through the second speed,
On the other hand, when the so-called R → D shift or the D → R shift in which the torque is reversed is performed, the torque is passed through the third speed, which is a higher speed, in order to further reduce the rattling noise and the shock due to the torque reversal. You will be able to choose. As a result, in the case of N → running range shift where the torque is not reversed, a shift with a small time lag can be achieved, and in the case of N → running range shift where the torque is reversed, rattling that occurs more due to the reversal of the torque can be achieved. The shift can be performed while keeping the sound and the shock small.

【Example】

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings. FIG. 2 schematically shows a gear train of an automatic transmission for a vehicle to which this embodiment is applied. This gear train includes a front planetary gear mechanism 1 and
It comprises three sets of planetary gear mechanisms, a rear planetary gear mechanism 2 and an overdrive planetary gear mechanism 3. The sun gear 4 of the front planetary gear mechanism 1 and the sun gear 5 of the rear planetary gear mechanism 2 are connected to each other.
Also, the carrier 6 of the front planetary gear mechanism 1 and the ring gear 7 of the rear planetary gear mechanism 2 are connected, and the carrier 6 and the ring gear 7 are connected to the carrier 8 of the overdrive planetary gear mechanism 3. I have. On the other hand, the turbine shaft 10 connected to the torque converter 9
The clutch C ₁ is provided between the ring gear 11 of the front planetary gear mechanism 1, the clutch C ₂ is provided between the turbine shaft 10 and the sun gear 4 of the front planetary gear mechanism 1. Furthermore, the one-way clutch F ₁ of the brake B ₁ represents between the sun gear 4 and 5 coupled transformer honey Chillon case 12 with provided, arranged in series to each other to each other
And the brake B ₂ is provided between the sun gear 4, 5 and transformer honey Chillon casing 12 so as to be parallel relationship to the brake B ₁ described above. Furthermore, between the carrier 13 and the transformer honey Chillon casing 12 of the rear planetary gear mechanism 2, and the brake B ₃ and the one-way clutch F ₂ are arranged in parallel. The overdrive planetary gear mechanism 3 sets the gear ratio to “1” or less to enable so-called overdrive traveling, and includes the carrier 8 and the sun gear 14.
A clutch C ₀ and one way clutch F ₀ between are arranged in parallel, further, the brake B ₀ is provided between the sun gear 14 and the case 12 and. The output of this gear train is supplied to the counter gear 16 connected to the ring gear 15 of the overdrive planetary gear mechanism 3.
It has been. Setting gear by gear train described above is performed Te cowpea to Yotsute selectively engage and release the respective clutch _{C 0 ~C 2, B 0 ~B} 3 hydraulic. FIG. 3 shows a main part of a hydraulic control device for that purpose. A manual valve 20 for switching a shift range is mechanically connected to a shift lever (not shown) in a driver's seat, and is manually operated by a driver to operate P (parking), R (reverse), N (neutral). , D (drive), 2 (second), and L (low) shift ranges are set. The hydraulic pump 30 is connected to the input port 21 of the manual valve 20.
The line pressure is adjusted by a well-known method by using a primary regulator valve 40 to control the hydraulic pressure generated by the line. In FIG. 3, reference numeral 50 denotes a 1-2 shift valve which shifts between a first speed and a second speed, and 60 denotes a second speed and a third speed.
2-3 shift valve for shifting to and from the speed, 70 is the third shift valve
3A and 3B show shift valves that shift between a fourth speed and a fourth speed, respectively. The spools 51, 61, 71 of the shift valves 50, 60, 70 are urged upward by springs 52, 62, 72 in the drawing. However, when line hydraulic pressure is supplied to the pilot ports 53, 63, and 73 of the shift valves 50, 60, and 70, the spools 51, 61, and 71 overcome the biasing forces of the springs 52, 62, and 72, and The oil passages formed in the respective shift valves 50, 60, 70 are switched by the movement of the spools 51, 61, 71 at this time. The pilot ports 53, 63 and 73 are connected to the output port 22 which is communicated with the input port 21 when the position of the manual valve 20 is set to the forward travel range of D range, 2 range and L range. In this connection,
2-3 Oil passage leading to pilot port 63 of shift valve 60
Solenoid valve S ₁ is interposed, mounted on 23. The oil passage 24 leading to the pilot port 73 of the pilot ports 53 and 3-4 shift valve 70 in addition 1-2 shift valve 50 solenoid valve S ₂ is interposed, attached. When the solenoid valves S ₁ and S ₂ are OFF, the ports 25 and 26 facing the oil passages 23 and 24 are closed to maintain the line oil pressure supplied to the oil passages 23 and 24 as it is. ON
In this state, the ports 25 and 26 are opened to drain the oil in the oil passages 23 and 24. The ON / OFF control of the solenoid valves S ₁ and S ₂ is controlled by ECT (Electronic Control Transmission) as described later.
This is performed by the control computer. Clutch C ₁ is communicated with the output port 22 of Maniyuaru valve 20, also clutch C ₂ is the spool 61 of the 2-3 shift valve 60 is supplied line pressure when pushed against the spring 62 Port 64.
Clutch C ₀ is in communication with the port 74 of the spool 71 is supplied line pressure in a state of being pushed upward in the drawing until I connexion limit position to the spring 72 of each port of the 3-4 shift valve 70 . The brakes B _{1 to} B ₃ are communicated with the ports 54 to 56 of the 1-2 shift valve 50, and the brakes B _{0 to} B ₃
Is connected to the port 75 of the 3-4 shift valve 70. With these structures, an appropriate shift range is selected by the manual valve 20, while the solenoid valves S ₁ and S ₂ are set to the fourth position.
As shown in the drawing, the first to fourth speeds are achieved by ON-OFF (ON is indicated by ○ and OFF is indicated by ×). In addition, engagement of clutches and brakes at each gear
The open state is also as shown in FIG. As shown in FIG. 5, the ECT control computer 80
Includes a throttle sensor 81 for detecting a throttle opening θ for reflecting an engine load (engine torque);
Vehicle speed sensor 82 for detecting vehicle speed N ₀ , N range, D range,
A shift position sensor 83 for detecting the position of a shift range such as a P range, a cooling water temperature sensor 84 for detecting a cooling water temperature of an engine, a brake sensor 85 for detecting that a brake has been depressed, and a drive with emphasis on power performance. Each signal of the pattern select switch 86 and the like for detecting which one of the driving and the fuel economy is emphasized by the driver is input. The ECT control computer 80 obtains these input signals, and drives the solenoid valves S ₁ and S ₂ in the hydraulic control device according to the throttle opening-vehicle speed shift map in the same manner as in the related art. Thus, the shift control of the first to fourth speed steps is executed. If the N → D shift is performed, and if the square control is not performed, the clutch is used to directly form the first speed.
Hydraulic pressure is supplied only to the C _1. However, when the square control is executed, an engagement command to a higher speed (second speed or third speed) is issued, and then an instruction to the first speed is issued. FIG. 6 shows a flow chart of this square control. In this flow chart, D → N → D (D is outside the drive range and includes forward ranges such as second (S) and low (L)) shifts (corresponding to shifts other than the first and second shifts) when the, Sukuoto control to via the second speed by T _D time is executed. In the case of R → N → D shift (corresponding to the second shift),
Sukuoto control to via the third speed only T _R time is executed. The specific flow will be described. Each flag F ₀ to F _3, and reset the timer T _1, T ₂ is performed as an initialization in step 101. Here, the flag F ₀ is a flag which is set to 1 when the N → D shift is executed, and set to 0 otherwise. Flag F ₁ is 1 when the N → R shift is executed, a flag which becomes zero otherwise. 1 when the flag F ₂ is executing the via to the second speed stage,
Otherwise, this flag is set to zero. Flag F ₃ is 1 when running through to the third speed stage,
Otherwise, this flag is set to zero. Timer T ₁ is a risk automatic timer counted starts when the via to the second speed stage is performed. Timer T ₂ are a risk automatic timer counted starts when the via to the third speed stage is performed. In step 102, the gear stage is determined from the vehicle speed and the throttle opening in the main routine as in the conventional case. In step 103, the flag F ₀ is determined. N
If F ₀ = 0 where the D → shift has not been performed, the flow proceeds to step 104, where it is determined whether the N → D shift has been performed. If the N → D shift is executed, the flag
F ₀ excisional to (step 105) to 1, when there is no execution of N → D shift determines execution of willing N → R shift to step 106. N → if there is an execution of the R, the excisional the F ₁ indicating that the N → R shift is performed in 1 (step 107). When the N → D shift execution flag F ₀ is set to 1, the flow proceeds from step 103 to step 108 after return. Here it is determined flag F ₁ indicating that the N → R shift is executed. If F ₁ is zero, i.e. N → D before the shift _{(∵F 0 = 1) N →} R shift is not performed (D →
If (N → D), the flow goes to step 109). In step 109 a determination is made of the flag F _2. When the flag F ₂ is zero, that is, when the instruction to the second speed stage in D → N → D shift is determined not yet been issued, step 11
Proceeds to 0 and issues an instruction to the 2nd gear, and the square timer T
It starts a count of _one (step 111), and excisional the execution flag F ₂ via to the second speed stage (step 11
2). Once F ₂ = 1, the flow will flow from step 109 to step 113. Here, comparing the risk auto timer T ₁ and the predetermined value T _D. If T ₁ <T _D , nothing is done and the process returns. If T ₁ ≧ T _D , an instruction to return to the first speed stage (step 114) is issued, and each flag F ₀ ,
F _1, performs a reset of the F ₂ (step 115) performs a reset of the disk auto timer T ₁ (step 116). Thus, in the case of the D → N → D shift, that is, in the case of the shift in which the torque is not reversed, the square control for achieving the second speed stage only during the period T _D is executed. On the other hand, in the case of an R → N → D shift (when the flag F ₁ becomes 1 and then the flag F ₀ becomes 1), F ₁ =
Since it is 1, it flows from step 108 to step 117.
Here the flag F ₃ is determined. F ₃ = 0, that is, R → N →
Before execution via the third speed stage in the D shift,
Instruct third gear (step 118), and use square timer T
It starts a _second count (step 119), and excisional the flag F ₃ to 1 to indicate that the way to the third speed stage is performed (step 120). Once the flag F ₃ = 1, the flow goes from step 117 to step 121. Here, we compare the risk auto timer T ₂ and the predetermined value T _R, in the case of T ₁ <T _R is returned without any, the return instruction to the first speed when becomes such T ₁ ≧ T _R (step 122), reset the flags _{F 0, F 1, F 3} ( step 123), and performs the reset of the disk auto timer T ₂ (step 124). Thus, when R → N → D shift has been performed, i.e., when the inverted shift torque has been performed, Sukuoto control via the third speed only between T _R is executed. According to this control flow, D → N where torque is not reversed
The → If the D shift has been performed, is Sukuoto control to via the second speed as in the conventional predetermined time T _D is performed, decrease in hydraulic or Sukuoto control is prevented time lag of increase is carried out . On the other hand, when the inverted R → N → D shift torque is executed, Sukuoto control to via the third speed only between the predetermined time T _R is executed. As a result, the output shaft torque can be suppressed low, and rattling noise and shock of the drive system due to rapid torque reversal can be reduced. As is clear from FIG. 4, the clutch C ₂ is
It is made to work at the speed and reverse. If slave connexion R → N → D shift has been performed in a short period of time, since the clutch C ₂ remains the hydraulic pressure supplied by the reverse stage, causing a drop in hydraulic pressure due to the operation of the servo system Thus, the third speed can be achieved. Accordingly, the time lag does not increase, and the rattling noise is greatly reduced as compared with the second speed. The reason why the square timer (time passing through the high speed gear) is changed between the D → N → D shift and the R → N → D shift is that the clutch C is not changed during the R → N → D shift. _This is because, since ₂ is still supplied, it takes a long time to return to the first gear, so that it is possible to return to the first gear earlier. Also, in this embodiment, since the reverse stage is one stage,
In the flowchart of FIG. 6, the D → N → R shift (corresponding to the first shift) is not particularly mentioned, but the D → N → R shift when the number of reverse stages is multi-stage is also R. Obviously, it can be considered in the same way as the → N → D shift. The high-speed reverse stage can be achieved in the gear train of this embodiment by, for example, engaging the clutches C ₂ , B ₀ , and B ₃ and releasing the clutch C ₀ . In this case, when the D → N → R shift in which the torque is reversed is performed, the shift is performed via the high-speed reverse stage. It can also be configured not to.

【The invention's effect】

As described above, according to the present invention, when the shift of D → N → R or R → N → D where the torque is reversed is performed, and when the other shift not reversed is performed. Since the high-speed gear to be changed is changed, an excellent effect is obtained in that it is possible to execute the square control at a level that does not cause any problem in the shock and the time lag at the time of shifting.

[Brief description of the drawings]

FIG. 1 is a block diagram showing the gist of the present invention, FIG. 2 is a skeleton diagram of a gear train of an automatic transmission for a vehicle to which an embodiment of the present invention is applied, and FIG. FIG. 4 is a hydraulic circuit diagram showing a main part of the hydraulic control device, FIG. 4 is a diagram showing a switching state of an electromagnetic valve when each shift range is achieved, and an engagement / operation state of a friction engagement device; FIG. 6 is a block diagram showing the input / output relationship of the computer for ECT control, and FIG. 80 ECT control computer, 81 Throttle sensor, 82 Vehicle speed sensor, 83 Shift position sensor, S ₁ , S ₂ … Solenoid valve, T ₁ … Square timer, T ₂ … ... disk auto timer, T _D, T _R ...... predetermined time (time for via high speed stage).

Continuation of front page (72) Inventor Masahiro Kojima 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Corporation (56) References JP-A-58-160658 (JP, A) JP-A-61-31747 (JP, A)

Claims (1)

(57) [Claims] A shift range detecting means for detecting a shift range from an N range to a forward range or a reverse range for temporarily achieving a speed other than the lowest speed. A shift control device for an automatic transmission configured to engage a coupling device and reduce a shock at the time of switching from the N range to the forward range or the reverse range, wherein the shift from the N range to the forward range or the reverse range is performed. Means for detecting whether or not is the first shift from the forward range to the reverse range via the N range or the second shift from the reverse range to the forward range via the N range. When the shift from the N range to the forward range or the reverse range is either the first shift or the second shift, and when the shift other than the first and second shifts is performed. In a case been made in preparative, the shift control apparatus for an automatic transmission characterized by comprising means for changing the type of gear position temporarily achieved, the.