JPH04366066A - Automatic transmission squat controller - Google Patents

Abstract

PURPOSE:To improve the performance of acceleration at what forms the shift step other than the lowest speed step temporarily at the time of changeover to a travel range from an N range, by conducting this formation to the shift step other than the lowest speed step only in a case in which a specific travel condition is satisfied. CONSTITUTION:At a squat controller which reduces a shift shock by making it pass through the shift step other than the lowest speed step temporarily when a shift range is changed over to a travel range from an N range, a vehicle speed detecting means A, an engine load detecting means B and an engine rotary speed detecting means C are provided, and at the same time a confirming means D to confirm a predetermined time To that is after changeover to the travel range from the N range, is provided. And the output signals of these respective means A-D are inputted at a command generating means E, and a command to form the shift step other than the lowest speed step is generated when three conditions, that is, zero vehicle speed, engine load being of more than predetermination and the rotary speed of an engine being more than a reference rotary speed based on engine load, are materialized within the predetermined time To.

Description

[Detailed description of the invention]

0001

[Industrial Application Field] The present invention relates to squat control of an automatic transmission, that is, an automatic transmission configured to reduce shift shock when switching from N range (neutral range) to drive range (forward or reverse range). The present invention relates to a squat control device for a transmission.

0002

[Prior Art] Japanese Patent Publication No. 50-709 discloses that in an electronically controlled automatic transmission, the first Discloses a technology (squat control) for passing through a gear other than the lowest gear. This squat control is shifted from N to D, and then
The first
Issue a command to engage a friction engagement device for forming a gear other than the first gear so that the gear is a gear other than the first gear, and then issue a command to form the first gear. It is something to put out.

For example, referring to the engagement diagram shown in FIG. 4, when shifting from N to D, normally the shift would be completed by simply engaging clutch C1, but In this case, first, a command to engage the clutch C1 and the brake B2 is issued to temporarily establish the second gear, and then the brake B2 is released to return the gear to the first gear.

[0004] As a result, the shock at the time of N→D shift can be alleviated to the extent that the gear ratio does not suddenly change, and the so-called squat phenomenon in which the tail portion of the vehicle sinks can be reduced.

[0005] Also, Japanese Patent Application Laid-open No. 116160/1983,
A technique is disclosed that executes this squat control only when the vehicle speed is zero and the engine rotation speed is equal to or higher than a predetermined value. This is done when the engine speed is high.
Considering that a D shift generates a particularly large shock, the design concept is based on the idea that it is better to give priority to a quick start for other N→D shifts.

By the way, this Japanese Patent Application Laid-Open No. 61-116160
According to the technique disclosed in the publication, it is determined whether or not to execute squat control based only on the state of the vehicle speed and engine rotational speed at the time of N→D shift.
There is a problem in that if the conditions of vehicle speed and engine rotational speed are not satisfied at the time of D shift, squat control will not be executed even if the conditions are satisfied a little later.

To put this problem more concretely, in recent years, so-called full-time four-wheel drive, which constantly drives the left and right front and left wheels, has become popular. When performing a sudden engagement start, the driving force is 4
By distributing the power to the wheels, it is possible to start the engine without losing much more drive power than with conventional two-wheel drive. Therefore, in a 4-wheel drive vehicle, the shocking input load torque that would be avoided by slipping due to tires exceeding their grip limit in a 2-wheel drive vehicle is directly applied to each member of the drive system, including the automatic transmission. As a result, the durability of these drive systems has become more of an issue than ever before.

Therefore, even if we take the condition that the accelerator opening (engine load) is above a predetermined value or the engine speed is above a predetermined value, we can only express the condition at the moment when the N→D shift is performed. I guess you were watching
The problem has arisen that sometimes adequate responses are not taken.

[0009] In view of these points, Japanese Patent Application Laid-Open No. 2-2106
4, regarding the execution of squat control at the time of N→D shift, not only the state at the moment of N→D shift, but also
A technology has been proposed that continues to make conditional judgments to some extent even after a shift and executes more detailed squat control that takes into account the durability of the drive system.

0010

[Problem to be Solved by the Invention] However, if the conditions for executing squat control are determined over a predetermined period of time, the probability that squat control will be executed increases accordingly; In other words, this means that the probability that the rapid acceleration performance required by the driver will not be satisfied increases.

[0011] When focusing on durability, when the engine load is not so high, even if the engine rotational speed is relatively high, the durability does not pose much of a problem. On the other hand, when the engine load is high, durability may become a problem even if the engine speed is relatively low.

[0012] The present invention has been made in view of these problems, and takes into account the viewpoint of ensuring the durability of the drive system, while at the same time realizing the drive characteristics requested by the driver as much as possible. It is an object of the present invention to solve the above problems by providing a squat control device for an automatic transmission that can perform the following steps.

[0013]

[Means for Solving the Problems] The present invention is directed to (A) in FIG.
As shown in the summary, an automatic transmission system is provided with means for detecting a shift range, and configured to temporarily form a gear other than the lowest gear when the shift range is changed from the N range to the driving range. The squat control device for the transmission includes means for determining a predetermined time T0 after switching from the N range to the travel range, means for detecting vehicle speed, means for detecting engine load, and detecting engine rotation speed. and within the predetermined time T0, when three conditions are satisfied: the vehicle speed is zero, the engine load is at least a predetermined value, and the engine rotation speed is at least a reference rotation speed set according to the engine load, the minimum The above-mentioned problem is solved by providing a means for issuing a command to form a gear stage other than the gear stage.

[0014] Furthermore, the present invention, as shown in FIG. In a squat control device of an automatic transmission configured to form a gear other than the lowest gear, a predetermined time T0 after switching from N range to driving range.
a means for determining the vehicle speed, a means for detecting the engine load, a means for detecting the engine speed, When established, the execution timer T1 is set according to the engine load and engine rotation speed.
The above-mentioned problem is also solved by providing a means for setting a gear position, and a means for issuing a command to form a gear position other than the lowest gear position for a time corresponding to the execution timer T1.

[0015]

[Operation] In the present invention, N→D (N→2, N→L,
When executing squat control during a shift (including N→R), instead of only considering the state at the moment when the N→D shift is performed, the predetermined period of time after switching from the N range to the D range is determined. If a predetermined condition is satisfied within this predetermined time, the squat control is executed. As a result, squat control can be executed promptly even when a predetermined condition is satisfied, for example, shortly after the N→D shift is performed.

[0016] Therefore, the N
→D shift can be achieved and the durability of the drive system can be ensured.

[0017] Here, in the first invention, the conditions for establishing squat control are that the vehicle speed is zero (including the case where it is substantially zero), the engine load is equal to or higher than a predetermined value, and the engine rotational speed is higher than the engine speed. It stipulates three conditions that are higher than or equal to the reference rotation speed set according to the load.

As a result, when the engine load is high (because durability problems are likely to occur), squat control is executed even when the engine speed is relatively low to ensure durability. When the speed is not very high, there is no particular problem in terms of durability even if the engine speed is quite high, so it is possible to discontinue squat control and configure the system so that it can respond to the driver's acceleration request. .

Further, in the second invention, when the conditions that the vehicle speed is zero and the engine load is equal to or higher than a predetermined value are established within a predetermined time T0, the execution timer T1, which is set depending on the engine load and the engine rotational speed, is activated. I am trying to perform squat control. As a result, when the engine load or engine speed is high, squat control is executed for a long time to ensure durability, and when the engine load or engine speed is low, the squat control execution time is shortened. This increases responsiveness and makes it possible to respond to the driver's acceleration requests.

[0020]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Examples of the present invention will be described in detail below 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 three sets of planetary gear mechanisms: a front planetary gear mechanism 1, 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. Further, the carrier 6 of the front planetary gear mechanism section 1 and the ring gear 7 of the rear planetary gear mechanism section 2 are connected, and these carriers 6 and ring gear 7 are connected to the carrier 8 of the overdrive planetary gear mechanism section 3. There is.

On the other hand, a clutch C1 is provided between the turbine shaft 10 connected to the torque converter 9 and the ring gear 11 of the front planetary gear mechanism 1. A clutch C2 is provided between them. Furthermore, sun gears 4 and 5 and a transmission case 12 are connected to each other.
A brake B1 is provided between the one-way clutch F1 and the brake B2, which are arranged in series with each other.
The sun gears 4, 5 and the transmission case 12 are arranged in parallel with the brake B1.
is established between. Furthermore, the rear planetary gear mechanism section 2
A brake B3 and a one-way clutch F2 are arranged in parallel between the carrier 13 and the transmission case 12.

The overdrive planetary gear mechanism 3 sets the gear ratio below "1" to enable so-called overdrive running, and has a clutch C0 and a clutch C0 between the carrier 8 and the sun gear 14. One-way clutch F
0 are arranged in parallel, and furthermore, a brake B0 is provided between the sun gear 14 and the case 12.

The output of this gear train is a counter gear 16 connected to a ring gear 15 of the overdrive planetary gear mechanism 3.

[0027] Setting of the gear position by the above-mentioned gear train is performed by selectively engaging and disengaging each of the clutches C0 to C2 and B0 to B3 using hydraulic pressure.

FIG. 3 shows the main parts of the hydraulic control device for this purpose. Manual valve 2 for changing shift range
0 is mechanically connected to a shift lever (not shown) in the driver's seat, and P (parking),
R (reverse), N (neutral), D (drive)
, 2 (second), and L (low) shift ranges.

The input port 21 of the manual valve 20 is supplied with line oil pressure, which is generated by a hydraulic pump 30 and regulated by a primary regulator valve 40 in a well-known manner.

In FIG. 3, reference numeral 50 indicates the first gear and the second gear.
1-2 shift valve that changes gears between the two gears, 60 a 2-3 shift valve that changes gears between the second and third gears, and 70 the third and fourth gears. 3-
4 shift valves are shown. The spools 51, 61, 71 of each shift valve 50, 60, 70 are urged upward in the figure by springs 52, 62, 72. However, each shift valve 50, 60, 7
When line hydraulic pressure is supplied to the pilot ports 53, 63, 73 of 0, each spool 51, 61, 71 overcomes the urging force of the springs 52, 62, 72 and is moved downward in the figure. each spool 51, 61
, 71, the respective shift valves 50, 6
The oil passages formed at 0 and 70 are switched.

The pilot ports 53, 63, and 73 are connected to the output port 22, which communicates with the input port 21 when the manual valve 20 is set to the D range, the 2 range, and the forward travel range of the L range. There is. For this connection, a solenoid valve S1 is interposed and installed in the oil passage 23 leading to the pilot port 63 of the 2-3 shift valve 60. Further, a solenoid valve S2 is interposed and installed in the oil passage 24 leading to the pilot port 53 of the 1-2 shift valve 50 and the pilot port 73 of the 3-4 shift valve 70.

These solenoid valves S1 and S2 maintain the line oil pressure supplied to each oil passage 23 and 24 by closing the ports 25 and 26 facing each oil passage 23 and 24 in the OFF state, and Turn on port 25
, 26 are opened to drain the oil in each oil passage 23, 24.

ON-OFF control of the solenoid valves S1 and S2 is performed by an ECT (Electronic Control Transmission) control computer, as will be described later.

The clutch C1 is connected to the output port 22 of the manual valve 20, and the clutch C2 is connected to the line hydraulic pressure when the spool 61 of the 2-3 shift valve 60 is pushed against the spring 62. The port 64 is connected to the port 64. Clutch C0 is 3-
4 The spool 71 of each port of the shift valve 70
is communicated with a port 74 to which line hydraulic pressure is supplied while being pushed upward in the figure to the limit position by a spring 72. Further, the brakes B1 to B3 are communicated with ports 54 to 56 of the 1-2 shift valve 50, and the brake B0 is communicated with the port 75 of the 3-4 shift valve 70.

With these structures, manual valve 2
0 to select an appropriate shift range, and turn the solenoid valves S1 and S2 ON-OFF as shown in FIG.
is indicated by ○, OFF is indicated by ×),
The first to fourth gears are achieved. The engagement and release states of the clutches, brakes, etc. at each gear stage are also shown in FIG. 4.

As shown in FIG. 5, the ECT control computer 80 includes a throttle sensor 81 that detects the throttle opening θ to reflect the engine load (engine torque), a vehicle speed sensor 82 that detects the vehicle speed V, A shift position sensor 83 for detecting the position of shift ranges such as N range, D range, P range, etc., an engine rotation speed sensor 84 for detecting engine rotation speed, a brake sensor 85 for detecting that the brake is depressed, and power. Among driving that emphasizes performance and driving that emphasizes fuel efficiency,
Signals such as a pattern select switch 86 for detecting which one has been selected by the driver are input.

The ECT control computer 80 obtains these input signals and drives the electromagnetic valves S1 and S2 in the hydraulic control device described above according to the throttle opening-vehicle speed change map, as in the conventional case. 1st gear - 4th gear
Executes gear shift control.

When the N→D shift is performed and squat control is not performed, hydraulic pressure is supplied only to clutch C1 in order to directly establish the first gear stage. However, when the conditions for executing squat control are met, an engagement command (clutch C
1 and a command to engage the brake B2), and then a command to the first gear (in this case, a command to release the brake B2) is issued. Note that the high speed stage to be formed does not have to be the second speed stage, but may be, for example, the third speed stage.

[0039] The execution condition of the squat control is that the predetermined time T
0, ■Vehicle speed V is close to zero and is less than V0, ■Throttle opening θ (engine load) is greater than or equal to a predetermined value, ■Shift range is not in N range, and ■Engine rotation speed Ne
All of the four conditions that are equal to or higher than the reference rotational speed Neo set according to the throttle opening degree θ are satisfied.

The reason is as follows.

■The reason why we set the condition that the vehicle speed V be below V0, which is close to zero, is because when the vehicle is moving, even if the N→D shift is performed, torque fluctuations will not be much of a problem. There is no need to perform squat control using
This is because it is better to form the first gear stage quickly.

[0042] Also, ■The reason why the engine load is set to be above a predetermined value is that when the engine load is low, the shock at the time of shifting from N to D is small, and when returning to the first gear after shifting to a high gear. This is because the shock may warp and become larger. In this way, if there is not much benefit from executing the squat control, it is better to shift directly to the first gear without executing the squat control because the vehicle can get ready to start more quickly.

[0043] Also, ■The reason why the shift range must not be in the N range is because when the driver actually operates the shift lever, he or she does not necessarily perform one operation without error. D→N or N→R
This is because operations such as →N are often executed. In such a case, even if the other squat conditions are satisfied, if the shift range had been returned to the N range at that stage, it would be pointless to perform squat control during the N→D shift. That's true. This condition that the shift range is not the N range means that the present invention does not execute squat control by considering only the state at the moment when the N→D shift is performed, but also for a predetermined period of time after the N→D shift is performed. This condition is significant because it is to be executed when a specific condition is satisfied within T0.

Finally, ■The engine rotation speed Ne is the reference rotation speed Ne set according to the throttle opening degree θ.
The condition that it be equal to or more than o was mainly taken into consideration to ensure durability; when the throttle opening degree θ is high, there is a problem in terms of durability even if the engine rotational speed Ne is not so high. When the throttle opening degree θ is not so high, even if the engine rotational speed Ne is relatively high, there is no problem in terms of durability. Therefore, in order to reflect this situation, the reference rotation speed Neo is mapped using the throttle opening θ as a parameter, and the engine rotation speed N
When e is higher than the mapped reference rotational speed Neo, it is determined that it is better to execute squat control in terms of durability.

Furthermore, if any one of the predetermined conditions (1) to (2) does not hold during the predetermined time T0, the gear is immediately returned to the first gear. This is because if even one of ■ to ■ does not hold true, there is no point in executing squirt control any further; rather, it is possible to start the vehicle more smoothly if the first gear is established as soon as possible. It is.

In this way, even if the predetermined condition is satisfied when the N-D shift is performed, the predetermined time T
One of the features of the present invention is that it is possible to develop a configuration in which squat control is immediately stopped when the condition is no longer satisfied within 0.0 seconds.

FIG. 6 shows a flowchart for determining conditions for this squat control.

In step 101, N→D(L, 2
) A shift determination (determination as to whether or not it is in the N range) is made. When the N→D shift is not performed (N shift), the process returns as is, and squat control is not executed. N
→If it is determined that the D shift has been performed, step 102
The process proceeds to step 21, where the control determination time T0 is set.

Thereafter, in step 103, it is determined whether the vehicle speed V is less than or equal to a predetermined value V0 close to zero. Here, when the vehicle speed V is equal to or higher than V0, that is, when it is determined that the vehicle is moving, the process returns as is and the squat control is not executed.

In step 104, the engine rotational speed Ne
It is determined whether or not the throttle opening degree θ corresponds to the map shown in FIG. That is, according to this map, squat control is not executed when the throttle opening is less than θ2, regardless of the engine rotational speed. Moreover, even when the throttle opening degree θ is θ2 or more, the reference rotational speed Neo according to the throttle opening degree θ at that time is
Squat control is not executed when the following conditions are met. As is clear from the map, when the throttle opening θ is low, the reference rotation speed Neo is set high, and as the throttle opening θ increases, the reference rotation speed Neo
is set low. This means that when the throttle opening θ is large, it is better to perform squat control even if the engine rotational speed Ne is low, and when the throttle opening θ is relatively low, even if the engine rotational speed is somewhat high, it is better to perform squat control. This is because, since there is no particular problem in terms of durability, it is more rational to quickly establish the first gear to satisfy the driver's acceleration request.

If ``YES'' is determined in step 104, the process proceeds to step 105, where the execution timer T1 is processed. This execution timer T1 is
The engine load and engine rotation speed are mapped as shown in FIG. As is clear from this map, when the throttle opening θ is low, the execution timer T
1 is set to be short, and on the other hand, the execution timer T1 is also set to be short even when the engine speed is low. This is because when the throttle opening θ is large, durability is difficult, so the execution time of squat control is lengthened to alleviate the shock.On the other hand, when the engine speed is high, durability is also difficult, so the execution time of squat control is This is because it is necessary to set it longer.

[0052] As a result, the squat control is executed only for a period of time that reasonably takes into account the throttle opening degree and engine rotational speed, making it possible to both ensure durability and improve start response. .

In step 105, it is determined that all the conditions for executing squat control are met, a higher gear than usual is instructed, and squat control is executed. This squat control is executed only during the execution timer T1 set in step 105.
When the count is out, the gear is returned to the first gear (step 107).

Note that steps 101 to 104 are repeatedly determined even during the execution timer T1, and even if the execution timer T1 is counting, if the vehicle speed is no longer zero, the steps are immediately executed. The program then proceeds to step 107 to return to the first gear.

[0055]

[Effects of the Invention] As explained above, according to the present invention, it is possible to execute squat control while also considering the durability of the drive system, and moreover, it is possible to satisfy the driver's acceleration request as much as possible. The excellent effect of being able to do this is obtained.

[Brief explanation of drawings]

FIG. 1 is a block diagram illustrating 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.

FIG. 3 is a hydraulic circuit diagram showing main parts of the hydraulic control device of the automatic transmission.

FIG. 4 is a diagram showing the switching state of the electromagnetic valve and the engagement/operating state of the frictional engagement device when each shift range is achieved.

FIG. 5 is a block diagram showing the input/output relationship of the ECT control computer.

FIG. 6 is a flowchart showing a control procedure executed by the apparatus of the embodiment.

FIG. 7 is a diagram showing an example of a map between throttle opening and reference (engine) rotation speed.

FIG. 8 is a diagram showing an example of a map when setting the execution timer T1.

[Explanation of symbols]

80...ECT control computer, 81...Throttle sensor, 82...Vehicle speed sensor, 83...Shift position sensor, S1, S2...Solenoid valve, T0...predetermined time, T1...Execution timer.

Claims (2)

[Claims] 1. An automatic transmission comprising means for detecting a shift range and configured to temporarily form a gear position other than the lowest gear position when the shift range is switched from the N range to the driving range. In the squat control device of N
Predetermined time T after switching from range to driving range
0, a means for detecting vehicle speed, a means for detecting engine load, and a means for detecting engine rotation speed; and means for issuing a command to form a gear other than the lowest gear when three conditions in which the engine rotation speed is equal to or higher than a reference rotation speed set according to the engine load are satisfied. Squat control device for automatic transmission. 2. An automatic transmission comprising means for detecting a shift range and configured to temporarily form a gear other than the lowest gear when the shift range is switched from the N range to the driving range. In the squat control device of N
Predetermined time T after switching from range to driving range
0, a means for detecting vehicle speed, a means for detecting engine load, a means for detecting engine rotational speed, and a condition in which the vehicle speed is zero and the engine load is equal to or greater than a predetermined value within the predetermined time T0. is established, the execution timer T1 is activated according to the engine load and engine rotation speed.
A squat control device for an automatic transmission, comprising: means for setting a gear position other than the lowest gear position for a time corresponding to the execution timer T1;