JP3660104B2 - Hydraulic control device for automatic transmission - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to an operating hydraulic pressure control device for an automatic transmission, and more particularly to an operating hydraulic pressure control device for an automatic transmission that reduces a selection shock when a neutral range is selected as a travel range.
[0002]
[Prior art]
Conventionally, as an operating hydraulic pressure control device for such an automatic transmission, a device described in Japanese Patent Laid-Open No. 3-28571 is known.
[0003]
This is a precharge pressure regulating means that temporarily raises the operating hydraulic pressure when the range signal is input and switches from the neutral range to the traveling range, and then suddenly drops to create a shelf pressure for precharging. Capacity adjustment pressure adjusting means for gradually increasing the hydraulic pressure from the time when the precharge pressure decreases to create a capacity adjustment pressure for the frictional engagement element, and adjusting the precharge pressure when switching from the neutral range to the travel range. The working hydraulic pressure is suddenly increased by the pressure means and then rapidly lowered to quickly prepare for fastening of the friction engagement element, and then the working hydraulic pressure is gradually increased by the capacity adjustment pressure adjusting means to increase the friction. The shock when the fastening element is completely fastened is reduced, and both the completion of the selection in a short time and the reduction of the shock are achieved.
[0004]
[Problems to be solved by the invention]
However, in such a conventional hydraulic pressure control device for an automatic transmission, the setting of the above shelf pressure at the time of selection and the subsequent slow increase of the hydraulic pressure are caused by the brake state of the vehicle on which the automatic transmission is mounted. For example, since it is uniquely set regardless of whether or not the brake is operated, there is a case where the completion of the selection (shifting) in a short time and the reduction of the shock are not sufficiently satisfied. There was a problem that. That is, since the degree of shock transmitted to the vehicle is different between the state where the brake is operated and the state where the brake is not operated, it is determined in a compromise manner without taking this into consideration. Both the completion of the process and the reduction of shock are not fully satisfied.
[0005]
The object of the present invention is to solve such a conventional problem, and when selecting, in particular, selecting from the neutral range to the traveling range, both when the brake is operating and when not operating, in a short time and accompanied by a shock. It is an object of the present invention to provide a hydraulic control device for an automatic transmission that can be performed without any problems.
[0006]
[Means for Solving the Problems]
In order to achieve such an object, according to the first aspect of the present invention, when the travel range is selected from the neutral range, the operating hydraulic pressure is temporarily increased and then rapidly decreased, and the pre-applied to the starting frictional engagement element. Precharge pressure adjusting means for generating a shelf pressure for charging, and capacity adjusting pressure adjusting means for gradually increasing the operating oil pressure from the time when the precharge pressure decreases to generate a capacity adjusting pressure of the starting frictional engagement element And a brake state determining means for determining a brake state of a vehicle on which the automatic transmission is mounted. The brake state determining means determines that the brake is operating. changing the said operating hydraulic pressure in at least lowering the time of the pre-charge pressure, as higher than the hydraulic pressure when the brake non-operating state when And it said that there was Unishi.
[0008]
According to a second aspect of the present invention, when selected from the neutral range to the travel range, the operating oil pressure is temporarily increased and then rapidly decreased to create a precharging shelf pressure for the starting frictional engagement element. An automatic transmission comprising: a pressure adjusting means; and a capacity adjusting pressure adjusting means for gradually increasing the operating oil pressure from the time when the precharge pressure is lowered to create a capacity adjusting pressure of the starting frictional engagement element. In the operating hydraulic pressure control device, there is provided brake state determining means for determining a brake state of a vehicle on which the automatic transmission is mounted, and the precharge pressure is lowered when the brake state determining means determines that the brake is operating. Patent that the rising speed of the hydraulic pressure from the point, so as to change to higher than the rising speed of the hydraulic pressure when the brake non-operating state To.
[0010]
According to the first aspect of the present invention, the brake state of the vehicle on which the automatic transmission is mounted is determined by the brake state determination means, and the operation at least when the precharge pressure decreases when the brake operation state is determined. The hydraulic pressure is changed to be higher than the operating hydraulic pressure when the brake is not operating . Therefore, preparation for fastening of the frictional engagement element can be quickly performed in the brake operation state without a large shock as compared with the brake non-operation state.
[0012]
According to the second aspect of the present invention, the brake state of the vehicle equipped with the automatic transmission is determined by the brake state determination means, and from the time when the precharge pressure decreases when the brake operation state is determined. The rising speed of the hydraulic pressure is changed so as to be higher than the rising speed of the hydraulic pressure from the time when the precharge pressure is lowered when the brake is not operating . Accordingly, the frictional engagement element can be fastened in the brake operation state more quickly than in the brake non-operation state without a large shock. On the other hand, when the brake is not operating, the rising speed of the operating hydraulic pressure is low, so there is no big shock.
[0014]
DETAILED DESCRIPTION OF THE INVENTION
The preferred embodiments of the present invention will be described in detail with reference to the embodiments described in the accompanying drawings. Each example is for explaining the invention and does not limit the invention. In fact, it will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the scope or spirit of the invention. For example, features illustrated or described as part of one embodiment can be used in other embodiments to yield additional embodiments. Throughout the description and the drawings, the same numbers are used for the same functional parts.
[0015]
FIG. 1 is a block diagram showing an embodiment of the present invention. 1 is an automatic transmission, 2 is an engine, and the automatic transmission 1 has a built-in gear train comprising a plurality of planetary gear units as is well known. The output rotation of the engine 2 is input to the gear train via the torque converter 3. That is, the turbine of the torque converter 3 is connected to the input shaft of the automatic transmission 1, and the pump impeller of the torque converter 3 is connected to the output shaft of the engine 2.
[0016]
Note that the gear train of the automatic transmission 1 is the same as that described in the above-mentioned Japanese Patent Laid-Open No. 3-28571, and each combination of ON / OFF switching of the first shift solenoid 42 and the second shift solenoid 44, Various gear speeds are obtained by combining the engagement and release of the frictional engagement elements. Incidentally, the starting frictional engagement element referred to in the present invention corresponds to a forward clutch in the drive range and a reverse clutch in the reverse range.
[0017]
Reference numeral 10 denotes a control unit constituted by a microcomputer or the like, and switching signals for the first shift solenoid 42 and the second shift solenoid 44 are outputted from a shift control means 200 provided in the control unit 10. The shift determination at this time is based on a predetermined shift schedule using the throttle opening signal obtained from the throttle sensor 202 for detecting the throttle valve opening of the engine and the vehicle speed signal obtained from the vehicle speed sensor 204 as parameters. Done.
[0018]
Reference numeral 24 denotes a line pressure solenoid. The line pressure solenoid 24 is constituted by, for example, an on-drain type solenoid valve, and the line pressure is controlled by duty control of the line pressure solenoid 24. Thus, the line pressure solenoid 24 is driven by a control signal output from the line pressure control means 206 provided in the control unit 10, and normally a signal corresponding to the throttle opening is output.
[0019]
Here, in the present embodiment, a precharge pressure adjusting means 210 and a capacity adjusting pressure adjusting means 212 are configured in the control unit 10, and these two means 210, 212 are used to travel from the neutral (N) range (D, R ) Range, for example, the line pressure control is performed when the neutral (N) range is selected to the drive (D) range.
[0020]
That is, the precharge pressure adjusting means 210 detects, for example, a signal selected from the neutral range, for example, the drive range, from the range switching signal generated when the selection lever 214 is operated, and will be described later. A control signal is output to the line pressure control means 206 according to the judgment result of the brake state judgment means 216, and the line pressure is temporarily increased rapidly and then controlled so as to rapidly decrease.
[0021]
The brake state determination means 216 can be configured, for example, to detect the state of the brake switch 5 that is “ON” or “OFF” in accordance with the depression operation of the brake pedal 4 of the vehicle. Similarly, the state of the side brake switch that is turned “ON” or “OFF” in accordance with the operation of the side (hand) brake of the vehicle may be detected.
[0022]
As shown in FIG. 2, the line pressure regulated via the precharge pressure regulating means 210 is rapidly increased to a certain shelf pressure Pc simultaneously with switching from the N range to the D range, and this shelf pressure Pc. Is continued for a predetermined time Tc, and then suddenly drops to a predetermined pressure Pv according to the determination result of the brake state determination means 216. The shelf pressure Pc is precharged to the aforementioned forward clutch, which is a starting frictional engagement element that is engaged when switching from the N range to the D range.
[0023]
On the other hand, the capacity adjustment pressure adjusting means 212 receives a precharge end signal from the precharge pressure adjusting means 210, receives a signal from the brake state determining means 216, and outputs a control signal to the line pressure control means 206, In accordance with the determination result of the brake state determination means 216, control is performed so as to increase by changing the increasing speed of the line pressure.
[0024]
That is, as shown in FIG. 2, the line pressure controlled by the capacity adjustment pressure adjusting means 212 corresponds to the determination result of the brake state determining means 216 after a predetermined time Tc has elapsed since switching from the N range to the D range. The pressure is increased from the predetermined pressure Pv at a predetermined speed according to the control time Ts until the forward clutch is completely engaged and the determination result of the brake state determination means 216.
[0025]
An example of a control procedure executed by the precharge pressure adjusting means 210 and the capacity adjusting pressure adjusting means 212 will be described with reference to the flowchart shown in FIG. This is executed every predetermined time.
[0026]
First, in step S1, it is determined whether or not the current range position is the N range. If “YES”, the process proceeds to step S2, and the flag F is set to 0. In step S3, a predetermined time Tc is set in the timer 1 provided in the precharge pressure adjusting means 210, and a predetermined time Ts is set in the timer 2 provided in the capacity adjusting pressure adjusting means 212. In step S4, the normal line pressure control is set.
[0027]
The timers 1 and 2 are decremented (-1) at regular intervals and stopped when they reach zero.
[0028]
On the other hand, if “NO” is determined in step S1, the process proceeds to step S5 assuming that the range is selected from the N range to the D range, and whether or not the timer 2 set in step S3 has become 0, that is, It is determined whether or not the fastening control time Ts has elapsed. In the case of “YES”, it means that the engagement control of the starting frictional engagement element has been completed, and the process proceeds to step S4 and is set to perform the normal line pressure control.
[0029]
If “NO” is determined in the step S5, the process proceeds to the line pressure transient control. First, in the step S6, whether or not the timer 1 becomes 0, that is, whether or not a predetermined precharge time Tc has elapsed. If “NO”, the process proceeds to step S8. In step S8, it is determined whether the brake switch 5 is “ON” or “OFF”. Here, in the case of “NO”, it is determined that the brake is not in operation, and the process proceeds to step S12 to set the line pressure PL to the precharge shelf pressure Pc1. On the other hand, in the case of “YES”, it is determined that the brake is not in operation, and the process proceeds to step S11, where the line pressure PL is set to the precharge shelf pressure Pc2 higher than Pc1.
[0030]
On the other hand, if “YES” is determined in the step S6, that is, if the precharge predetermined time Tc is completed, the process proceeds to a step S7 to determine whether or not the flag F is 1. If "NO", the process proceeds to step S9, and it is determined whether the brake switch 5 is "ON" or "OFF". Here, in the case of “NO”, as described above, it is determined that the brake is not operating, and the process proceeds to step S14 where the line pressure PL at the time when the precharge pressure decreases is set to the predetermined pressure Pv1. To do. On the other hand, in the case of “YES”, the brake operation state is assumed, and the process proceeds to step S13, where the line pressure PL is set to a predetermined pressure Pv2 higher than Pv1. Then, after step S13 and step S14 described above, the process proceeds to step S17 and step S18, respectively, and the flag F is set to 1, and this routine ends.
[0031]
On the other hand, if “YES” is determined in step S7, that is, if the predetermined pressure Pv1 or Pv2 has already been set, the process proceeds to step S10, and the line pressure PL is changed from the predetermined pressure Pv1 or Pv2 to the brake state. It is determined whether the brake switch 5 is “ON” or “OFF” in order to increase at a predetermined speed. Here, in the case of “NO” in the brake non-operating state, the process proceeds to step S15, and the line pressure PL is set to increase from the predetermined pressure Pv1 when the precharge pressure decreases at an increasing rate of the inclination θt1. To do. On the other hand, in the case of “YES” in the brake operation state, the process proceeds to step S16, and the line pressure PL is increased from the predetermined pressure Pv2 at the time when the precharge pressure is decreased to an increase rate of the inclination θt2 larger than the inclination θt1. Set to increase.
[0032]
Therefore, in the hydraulic control device for an automatic transmission according to the present embodiment, as shown in FIG. 2, when the line pressure is supplied from the N range to the D range and the line pressure is supplied to the forward clutch, the brake is not operated. In the state, first, the hydraulic pressure of the precharge shelf pressure Pc1 is introduced into the forward clutch, and the precharge portion necessary for preparation for fastening the forward clutch is quickly filled. Since the pressure after filling is set to a lower value Pv1, excessive slipping of the clutch is prevented without a large shock. Further, after the precharge, if the line pressure is increased at the gentle rising speed θt1, the actual engagement is completed in the engagement time (TOFF) without a large shock (shown as SOFF in FIG. 2).
[0033]
On the other hand, in the brake operation state, first, the hydraulic pressure of the precharge shelf pressure Pc2 higher than Pc1 is introduced into the forward clutch, so that the precharge portion necessary for preparation for fastening of the forward clutch is more quickly filled. And since the pressure after this filling is set to the higher value Pv2, the excessive slip of a clutch is prevented. Furthermore, since the line pressure is increased at a higher ascending speed θt1 after precharging, the engagement is completed in a time (TON) shorter than the engagement time (TOFF) when the brake is not operated. Here, the shock (SON) shown in FIG. 2 is apparently larger than SOFF, but is not so much transmitted to the vehicle during the braking operation, so it actually becomes smaller.
[0034]
In the above-described embodiment, the example in which the driving range is selected from the N range has been described based on the example of the N to D range. However, this is also applied to the case where the N to R range is selected. Needless to say.
[Brief description of the drawings]
FIG. 1 is a block diagram showing an embodiment of the present invention.
FIG. 2 is a time chart for explaining an operation according to the embodiment of the present invention.
FIG. 3 is a flowchart illustrating an example of a control procedure according to the embodiment of this invention.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Automatic transmission 2 Engine 3 Torque converter 10 Control unit 24 Line pressure solenoid 202 Throttle sensor 204 Vehicle speed sensor 210 Precharge pressure regulation means 212 Capacity adjustment pressure regulation means 216 Brake state judgment means

Claims (2)

Precharge pressure regulating means for temporarily increasing the operating hydraulic pressure and then rapidly lowering it to create a shelf pressure for precharging to the starting frictional engagement element when selected from the neutral range to the traveling range;
In the hydraulic pressure control device for an automatic transmission, comprising a capacity adjustment pressure adjusting means for gradually increasing the operating oil pressure from the time when the precharge pressure is lowered to create a capacity adjustment pressure of the starting frictional engagement element,
Brake state determination means for determining a brake state of a vehicle on which the automatic transmission is mounted is provided, and the operating hydraulic pressure at least when the precharge pressure is lowered when the brake state determination means determines that the brake operation state exists. Is changed so as to be higher than the hydraulic pressure when the brake is not operated . Precharge pressure regulating means for temporarily increasing the operating hydraulic pressure and then rapidly lowering it to create a shelf pressure for precharging to the starting frictional engagement element when selected from the neutral range to the traveling range;
In the hydraulic pressure control device for an automatic transmission, comprising a capacity adjustment pressure adjusting means for gradually increasing the operating oil pressure from the time when the precharge pressure is lowered to create a capacity adjustment pressure of the starting frictional engagement element,
Brake state determination means for determining a brake state of a vehicle on which the automatic transmission is mounted is provided, and the operating hydraulic pressure from the time when the precharge pressure decreases when the brake state determination means determines that the brake operation state is present. The operating hydraulic pressure control device for an automatic transmission is characterized in that the rising speed of the automatic transmission is changed so as to be higher than the rising speed of the operating hydraulic pressure when the brake is not operated .

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