JP2936958B2 - Hydraulic control device for automatic transmission - Google Patents

Abstract

PURPOSE:To prevent shift shock at multiple shifting through mannual operation from being deteriorated. CONSTITUTION:An oil pressure control device of an automatic transmission A by which shifting can be carried out based on mannual operation and engaging oil pressure of a frictional engaging device upon shifting, is provided with a multiple shift detection means 1 which detects that a second shifting command is made while a first shifting is carried out through mannual operation, and a boost forbidding means 2 which forbids boosting of engaging oil pressure for the second shifting while allowing boosting of engage oil pressure for the first shifting in the case where the second shifting is commanded while the first shifting is carried out through mannual operation. With the constitution, deterioration of shift shock can be prevented because the frictional engaging device is not boosted during shifting.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic transmission for a vehicle, and more particularly to a hydraulic control device for an automatic transmission provided with a mechanism that causes a shift in response to a manual operation such as range switching.

[0002]

2. Description of the Related Art As is well known, an automatic transmission for a vehicle appropriately engages / disengages a plurality of frictional engagement devices which are engaged / disengaged by hydraulic pressure based on running conditions such as vehicle speed and engine load. By doing so, the gear stage suitable for the running state is set. The determination of the shift speed is performed by selecting a shift speed corresponding to a detected traveling state such as a vehicle speed from a shift diagram provided in advance. The general tendency of the shift speed determined by the shift diagram is such that the higher the engine load is, and the higher the vehicle speed is, the higher the speed stage is selected. However, in actual driving, various types of driving are required, such as maintaining the vehicle at a low gear to a certain speed to temporarily increase the acceleration, and upshifting at a relatively low speed to improve fuel efficiency and quietness. Required. Therefore,
A general automatic transmission is capable of setting a forward speed up to a third speed or a second speed in addition to a drive range capable of setting a forward or fourth speed.
A range and an L range in which the forward gear up to the first speed or the second speed can be set are provided, and the driver manually selects one of these ranges by operating the shift lever.

When the S range or the L range is selected, the manual valve in the hydraulic control device is switched to supply a hydraulic pressure to a predetermined brake or clutch, so that the engine brake is effective even at a low speed. The shift diagram corresponding to the range is set. That is, for example, when the S range is selected, the upshift line between the first speed and the second speed and the second shift from the third speed
A shift diagram with a downshift line from the second speed to the first speed and the second speed is set, and the shift speed is determined based on this. When the L range is selected, the third speed
A shift diagram with a downshift line from the second speed to the first speed and a second speed is set, and the shift speed is determined based on this.

Therefore, if the vehicle shifts to the S range when the vehicle is traveling with the L range set, for example, the traveling state at that point in the shift diagram for the L range is not limited to the first speed state even for the S range. In the shift diagram, if it corresponds to the second speed state, an upshift from the first speed to the second speed occurs with the switching of the range. Such a shift operation can be arbitrarily performed by the driver, so that the automatic transmission has the same degree of freedom of shifting as the manual transmission in this respect. Therefore, a conventional hydraulic control device for an automatic transmission, which temporarily increases the line hydraulic pressure at the time of a shift based on a manual operation to improve the responsiveness of the shift, is disclosed in, for example, JP-A-5-1763. Have been.

[0005]

When performing the above-described so-called line hydraulic pressure increase control, the torque applied to each friction engagement device varies depending on the type of shift, the vehicle speed, and the like. The step-up condition is stored as a map for each type of shift, for example, and whenever a shift based on a manual operation is determined, the step-up condition suitable for each type of shift is read. Therefore, as in the above-described automatic transmission, an L range and an S range are provided in addition to the D (drive) range as a range for forward running, and the pressure increase control of the line hydraulic pressure is performed during gear shifting based on manual operation. When performing an automatic transmission, shifting from the L range to the S range, and then shifting to the D range, upshifting from the first gear to the third gear via the second gear, the first gear is shifted to the third gear. While the shift to the second speed is being executed, the boost control for shifting to the third speed is instructed. In such a case, the hydraulic pressure supplied to the friction engagement device at the time of shifting from the first speed to the second speed temporarily increases due to the boost control for shifting from the second speed to the third speed. As a result, there is an inconvenience that the shift shock increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and is a hydraulic control device for performing a boost control at the time of gear shifting based on a manual operation. It is another object of the present invention to provide a hydraulic control device in which the shift shock does not deteriorate.

[0007]

According to the present invention, in order to achieve the above-mentioned object, the configuration shown in FIG. 1 is adopted. That is, according to the present invention, in the hydraulic control device of the automatic transmission A which can execute the shift based on the manual operation and increases the engagement hydraulic pressure of the friction engagement device during the shift, the first shift based on the manual operation is performed. Multiple shift detecting means 1 for detecting that a second shift has been commanded while performing the first shift, and a first shift when a second shift has been commanded while performing the first shift based on a manual operation. Pressure increase inhibiting means 2 for permitting the increase of the engagement hydraulic pressure for the second shift and prohibiting the increase of the engagement hydraulic pressure for the second shift.

[0008]

The automatic transmission A according to the present invention can perform not only a shift based on the running state but also a shift based on a manual operation. The manual operation includes, in addition to the switching of the travel range, an operation of directly selecting a gear position and an operation of causing an upshift or a downshift.Therefore, the present invention also includes an automatic transmission having a manual shift function. It is targeted. If the shift based on such a manual operation is a multiple shift in which the second shift is commanded during the execution of the first shift, the multiple shift detecting means 1 detects this. In the case of gear shifting based on manual operation, basically,
The engagement hydraulic pressure of the friction engagement device is increased. However, in the case of the above-described multiple shift, the engagement hydraulic pressure increase control based on the second shift is inhibited by the increase inhibition means 2. Therefore, the engagement hydraulic pressure from the start of the first shift to the end of the second shift becomes a pressure controlled for the first shift, and as a result, the engagement hydraulic pressure is increased during the shift. Since there is no
Deterioration of shift shock is prevented.

[0009]

Next, the present invention will be described based on embodiments. FIG. 2 is a block diagram schematically showing an embodiment of the present invention.
In addition to selecting a traveling range, various controls such as a shift control, a hydraulic control during a shift, an on / off control of a lock-up clutch (not shown), and a line hydraulic control are electrically performed. I have.

The shift mechanism 10 includes a parking (P) range, a reverse (R) range, a neutral (N) range, a drive (D) range, a second (S) range, The low (L) range is selected, and the manual valve (not shown) of the hydraulic control device 12 connected to the shift lever 11
Is switched to a state corresponding to each range, and shift position signals of the D range, the S range, and the L range are output to the electronic control unit (ECU) 13.

The hydraulic control device 12 includes first to third solenoid valves S1 to S3 for shifting, and a linear solenoid valve SLT for regulating line oil pressure.
A linear solenoid valve SLU for controlling a lock-up clutch and a linear solenoid valve SLN for controlling a back pressure of an accumulator (not shown) are provided. That is, among these solenoid valves, the first to third solenoid valves S1 to S3 are turned on.
By operating or OFF, a shift valve (not shown) is switched to set a predetermined gear position, and a linear solenoid valve SLT for regulating line oil pressure is provided with a throttle opening. The pressure is controlled in accordance with the degree, and is adjusted to a line oil pressure corresponding to the throttle opening, and the line oil pressure is temporarily increased during a gear shift based on a manual operation.

The electronic control unit 13 is mainly composed of a central processing unit (CPU), a storage unit (RAM, ROM) and an input / output interface, and includes a shift diagram for determining a shift stage. Various maps are stored, and in addition to the shift position signal from the shift mechanism 10, a vehicle speed V, a throttle opening θ, and other various signals are input. The electronic control unit 13 determines the gear position to be set, the engagement / disengagement of the lock-up clutch or the line oil pressure to be set based on the input signal, and, based on the determination result, the above-described solenoids. A signal is output to the valve.

The electronic control unit 13 and the hydraulic control unit 12 perform a shift operation based on a manual operation, that is, a case in which the shift lever 11 is operated to change the range and the shift operation is performed accordingly. In addition, the hydraulic pressure (line hydraulic pressure) supplied to a friction engagement device such as a clutch or a brake is temporarily increased. That is, when the oil pressure is supplied to engage the friction engagement device, first, after the oil fills the interior of the oil passage and the space portion of the hydraulic servo mechanism, the piston moves and the friction engagement device starts to be engaged, The time required for the oil to fill the inside of the oil passage and the space of the hydraulic servo mechanism becomes a time lag for shifting. In the case of gear shifting based on manual operation, the driver is conscious of gear shifting, and the above-mentioned time lag may cause a delay in gear shifting response. To reduce the time lag,
At the time when the gear shift actually starts (for example, at the time when the inertia phase starts), the line hydraulic pressure is returned to the original pressure, and the response delay is shortened as much as possible. The degree and time of the pressure increase are set in advance as a map for each type of shift, and values read out according to the detected type of shift are adopted.

This boost control is for reducing the time lag of the shift as described above. The line oil pressure, ie, the engagement pressure during the shift is adjusted to a predetermined value corresponding to the throttle opening in order to prevent a shift shock. Pressure must be maintained. Therefore, in the above-described control device, in the case of a so-called multiple speed change in which the speed change based on the manual operation is continuously performed, the pressure increase control is performed as described below to prevent the deterioration of the speed change shock.

FIG. 3 is a flowchart showing a control routine for boost control during the multiple shift. First, in step 1, the throttle opening is read, and then the flag F
Is determined to be "2" (step 2). When the flag F is set to “0”, it indicates that the line oil pressure is not being controlled at the time of shifting, and when it is set to “1”, it indicates that the line oil pressure is under pressure control. Is set to "2", indicating that normal line oil pressure control is being performed during gear shifting.

If the result of the determination in step 2 is "NO", it is further determined whether or not the flag F is "1" (step 3). If the result of the determination is "no", the operation proceeds to step 4 to determine whether or not a manual upshift is instructed. This is because, for example, the shift lever 11 is set to L
This is an upshift that occurs when the shift diagram used is switched by moving from the range position to the S range position, from the S range position to the D range position, or from the L range position to the D range position. . This determination is made because the time from when the shift lever 11 is operated to when the shift is actually started is regarded as a shift response delay only in such a manual upshift. is there.

If the decision result in the step 4 is "YES", in a step 5 it is decided whether or not the current gear before the shift is the first speed. That is, the multiple shift based on the manual operation described above is limited to the upshift from the first speed. It should be noted that whether or not the first speed is set is determined by the first
The answer is "yes" because the previous shift for setting the speed has been completed.

As described above, in the case of gear shifting based on manual operation, the line hydraulic pressure increase control is performed. If the result of the determination in step 5 is "yes", a timer TUP for line hydraulic pressure increase control is set. Start (step 6). Then, it is determined in step 7 whether or not the timer value exceeds a predetermined time α. If the determination result is “no”, the flag F is set to “flag” to indicate that the line hydraulic pressure is being increased. 1 "is set (step 8).
The time α is the line pressure increasing time, which is predetermined for each type of shift and throttle opening.
In step 9, a signal is output to the linear solenoid valve SLT for controlling line oil pressure so as to increase the line oil pressure to a predetermined pressure. Specifically, this is performed by changing the current value or the duty ratio. In addition,
As these values, values predetermined in accordance with the type of shift, the throttle opening, and the like are used.

Further, in step 10, it is determined whether or not the shift has been completed, and if the determination result is "yes",
After the flag F is set to "0" (step 11), the process returns. If the determination result is "no", the process immediately returns.

That is, in the case of a multiple shift based on a manual operation, only the line oil pressure increase control set according to the upshift from the first speed, which is the first shift, is executed. No boost control for shifting is performed.

On the other hand, if the count value of the timer TUP exceeds the time α, that is, if the result of the determination in step 7 is “yes”, the timer TUP is cleared (step 12), and then the flag F is reset. It is set to "2" (step 13), and further as a line hydraulic control instruction signal,
Output an instruction signal for normal shift control (step 1)
4). Then, the process proceeds to step 10. Therefore, the line oil pressure temporarily increases before the shift starts,
The filling of the pipeline and the space portion of the hydraulic servo mechanism with the oil becomes faster, and the response delay of the shift is improved.

When the shift determination in step 4 is "NO" because it is not a manual upshift, and when the determination result in step 5 is "NO" because the current gear is not the first speed. Then, the process proceeds to step 15 to set the flag F to "2", and then proceeds to step 14.

If the result of the determination in step 3 is "yes" because the line hydraulic pressure is being increased, step 4 to step 6 are skipped and step 7 is executed.
Proceed to. Further, if the result of the determination in step 2 is "yes" because the control of the line oil pressure during the normal shift has already been performed, the process immediately proceeds to step 10.

Time chart when the above-described line oil pressure boost control is performed when multiple shifts from the first speed to the third speed occur as the shift lever 11 is moved from the L range position to the D range position. Is shown in FIG. FIG.
In the graph, the solid line indicates a change in each value when the control according to the present invention is performed, and the broken line indicates a change in each value when the boost control during the second shift is also performed. As is known from FIG. 4, by performing the pressure increase control of the line oil pressure only at the time of the upshift from the first speed to the second speed, the clutch pressure changes smoothly, and the sudden change of the output shaft torque, that is, Shift shock is prevented. On the other hand, if the pressure increase of the line hydraulic pressure is also performed for the upshift from the second speed to the third speed, this control increases the line hydraulic pressure during shifting, so that the clutch pressure temporarily increases. Accompanying this, the output shaft torque changes suddenly, and the shift shock worsens.

In the above embodiment, the continuation period of the line oil pressure is set by a timer. However, the present invention is not limited to the above embodiment.
The start of the shift may be detected, and the pressure increase control of the line oil pressure may be continued until the start of the shift. Further, the present invention can be applied to an automatic transmission in which a shift is generated based on a manual operation. Therefore, the automatic transmission has a function of outputting an upshift signal or a downshift signal by manual operation. Alternatively, it may have a function of selecting a gear position by manual operation. Further, it is needless to say that the present invention is not limited to the case where the pressure increase of the engagement hydraulic pressure of the friction engagement device in the case of the manual upshift from the first speed to the third speed is performed.

[0026]

As is apparent from the above description, according to the control device of the present invention, the engagement hydraulic pressure of the friction engagement device is temporarily increased at each shift during manual shifting. In addition to being able to improve the shift delay, in the case of a so-called multiple shift, it is possible to prevent the engagement hydraulic pressure of the friction engagement device from increasing during the shift and effectively prevent deterioration of the shift shock. it can.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a schematic block diagram showing one embodiment of the present invention.

FIG. 3 is a flowchart showing an example of a control routine of a line oil pressure at the time of a manual shift by the control device of the present invention.

FIG. 4 is a time chart showing changes in an input rotation speed, an output shaft torque, a hydraulic pressure, and a duty output signal during a manual upshift from a first speed to a third speed.

[Explanation of symbols]

 1 Multiple shift detection means 2 Boost prohibition means

Continuation of the front page (56) References JP-A-5-1763 (JP, A) JP-A-6-2762 (JP, A) JP-A-4-83964 (JP, A) JP-A-5-99325 (JP) JP-A-2-89860 (JP, A) JP-A-63-40655 (JP, U) (58) Fields investigated (Int. Cl. ⁶ , DB name) F16H 59/00-61/12 F16H 61/16-61/24 F16H 63/40-63/48

Claims (1)

(57) [Claims] 1. A hydraulic control apparatus for an automatic transmission capable of executing a shift based on a manual operation and increasing the engagement hydraulic pressure of a friction engagement device during the shift, wherein the first shift based on the manual operation is performed. Multiple shift detecting means for detecting that a second shift has been commanded during the first shift, and a first shift when a second shift has been commanded while performing the first shift based on a manual operation. Pressure increase inhibiting means for permitting the increase of the engagement hydraulic pressure for the second gear and prohibiting the increase of the engagement hydraulic pressure for the second shift.