JPH0578454B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a starting clutch control device for an automatic transmission for controlling the clutch engagement pressure of a starting clutch that is engaged at the time of starting.

(Prior Art) As a conventional starting clutch control device, for example, one described in Japanese Patent Application Laid-open No. 13156/1983 is known.

In this conventional device, a discharge oil passage connected to an oil tank is branched from a supply oil passage that supplies hydraulic pressure to the starting clutch and other starting devices of an automatic transmission, and this discharge oil passage is closed in a demagnetized state and then in an energized state. In a creep prevention device including a solenoid valve that is opened, the energizing circuit of the solenoid valve is tripped a predetermined number of times when the solenoid valve is returned from an energized state to a demagnetized state.

Therefore, in this conventional device, when the creep prevention device is released from the operating state, the starting clutch is engaged using chopping control (control that repeatedly turns ON and OFF according to a set time, which is the same as duty control). By doing so, it was intended to prevent a shock when starting due to sudden clutch engagement.

Incidentally, the creep phenomenon refers to the phenomenon in which, in a vehicle equipped with an automatic transmission, if the transmission is left in the running position (especially in a position with a large gear ratio) while the vehicle is stopped, the drag torque of the torque converter causes the driver to A creep prevention device is a phenomenon in which a vehicle tries to move forward or backward against the vehicle's will.A creep prevention device is a device that is engaged when the automatic transmission is in neutral, in a low gear, or in a driving position under conditions where creep occurs. A device that prevents the creep phenomenon by placing the clutch in a slippingly engaged state to cut off or reduce the transmitted torque.

(Problem to be Solved by the Invention) However, with such a conventional device, the starting clutch is primarily engaged gradually through chopping control, regardless of the increase in engine speed at the time of starting. Therefore, there was a problem in that the constant chopping control was not responsive to various throttle openings at the time of starting when the engine speed before engagement of the starting clutch was different.

For example, if the setting is set to prevent clutch slippage or shock from occurring at a medium throttle opening when starting, then at a high throttle opening the clutch will slip and the start will be delayed. On the other hand, when the throttle opening is low, the clutch is suddenly engaged, resulting in a shock.

(Means for Solving the Problems) The present invention has been made for the purpose of solving the above-mentioned problems, and to achieve this purpose, the present invention employs the following means. .

The solution of the present invention will be described with reference to the conceptual diagram of the claim shown in FIG. A fastening pressure control means 4 provided in the hydraulic pressure supply path 3 controls the fastening pressure of the starting clutch, and when a signal indicating the start time is inputted from the input sensor 6, a control signal to gradually increase the clutch fastening pressure is applied to the fastening pressure. A starting clutch control device for an automatic transmission comprising: a control means 7 for outputting an output to the control means 4; It includes an engine output sensor 602 that directly or indirectly detects the drive output, and controls the control means 7 with a control signal that allows a clutch engagement pressure at or near the maximum to be obtained from the start of the start until the turbine rotational speed decreases by a predetermined value. , and then outputs a control signal that provides a clutch engagement pressure that corresponds to the engine output.

(Function) Therefore, in the starting clutch control device of the present invention,
As described above, the control means outputs a control signal that provides the maximum or near maximum clutch engagement pressure from the start of the start until the turbine rotational speed decreases by a predetermined value, and then outputs a control signal that provides the clutch engagement pressure in accordance with the engine output. By using a means of outputting a control signal that can obtain the maximum clutch engagement pressure at the initial stage of starting, a starting system is established in which there is no delay in hydraulic response due to the signal output that temporarily obtains the maximum or near maximum clutch engagement pressure, and after that, It is possible to perform starting clutch control in which the clutch engagement force is gradually increased in accordance with the engine output.

Then, the temporary signal output time at the initial stage of starting is
By setting the turbine rotation speed to decrease by a predetermined value from the start of the start, it is responsive to the starting throttle opening. For example, when starting from a low throttle opening and the engine speed is low before the clutch is engaged, The signal output time for obtaining the maximum or near-maximum clutch engagement pressure is short, preventing a shock caused by sudden clutch engagement. The signal output time is long and the starting clutch can be prevented from slipping.

(Example) Hereinafter, an example of the present invention will be described in detail with reference to the drawings.
In describing this embodiment, an example will be taken of a starting clutch control device for an automatic transmission equipped with a creep prevention device that performs a control operation after the creep prevention is released.

First, the configuration of the embodiment will be explained with reference to FIG.

10 is a starting clutch control device of the embodiment, which includes a torque converter (fluid coupling) 11, a starting clutch 12, an oil pressure modulator (clamping pressure control means) 13 having a solenoid 14 inside, a control unit 15, and an input. It is equipped with a sensor 16, and each configuration will be described below.

The torque converter 11 is a type of fluid coupling that transmits the rotational driving force from the engine by increasing the torque up to a predetermined rotational state, and is connected to a pump connected to a drive input shaft 17 to which the rotational driving force from the engine is input. It is composed of an impeller 18, a turbine runner 19 to which the driving force from the pump impeller 18 is transmitted via fluid, and a stator 21 fixed to the transmission case 20 via a one-way clutch. Turbine runner 19 is connected to drive output shaft 22 .

The starting clutch 12 engages gear elements of a gear train such as planetary gears of an automatic transmission,
This is a clutch provided to transmit the driving force from the drive output shaft 22 to the mission output shaft 23 at the time of starting.
a clutch drum 24 connected to the clutch drum 24, and a clutch plate 25 provided on the clutch drum 24.
The clutch plate 25 includes a clutch hub 27 provided with clutch plates 26 arranged at alternate positions, a clutch piston 28 provided on the side of the clutch hub 27, and the clutch piston 28.
A piston chamber 29 is provided with a control hydraulic pressure Pc for operating the piston chamber 29.

A transmission output shaft 23 is connected to the clutch hub 27 via a gear train (not shown) or the like.

Oil pressure modulator (hereinafter referred to as OPM)
(abbreviated as ) 13 is a line pressure oil line 30 to which line pressure P _L , which is the discharge pressure from the oil pump regulated by a pressure regulator valve, is supplied.
This OPM 13 and the piston chamber 29 of the starting clutch 12 are connected by a control pressure oil passage 31.

This OPM 13 is a proportional solenoid valve type in which the spring force of the pressure reducing valve is replaced by the electromagnetic force of the solenoid 14, and the output port pressure increases according to the current value to the solenoid 14 (see Figure 3). 32 includes a spool 33, a control pressure input port 34, a control pressure output port 35, a drain port 36, a tire flam 37, a spool operating piston 38, an air chamber 39, a communication passage 40, and a pressure oil chamber 4.
1, a solenoid 14 is provided, the solenoid 14
The spool 33 operates due to the balance between the electromagnetic force (force pushing the spool 33 to the left in the figure) and the hydraulic pressure by the pressure oil chamber 41 (force pushing the spool 33 to the right in the figure), and the drain port 36 opens and closes. The control pressure from the output port 35 is determined by the degree.

The control unit 15 uses an on-vehicle microcomputer, and includes an input circuit 151, a RAM (random access memory) 152, a ROM (read only memory), and an internal circuit.
153 (memory), a CPU (central processing unit) 154, a clock circuit 155, and an output circuit 156.

As the input sensors 16, a shift switch 161, an idle switch 162, an output shaft rotation speed sensor 163, an engine rotation speed sensor 164, and a turbine rotation speed sensor 165 are provided.

The input circuit 151 sends the signals (p), (i), (no), (ne), and (nt) from the input sensor 16 to the CPU 15.
This circuit converts the signal into a digital signal that can be processed in step 4.

The RAM 152 is a readable and writable memory, and is used for each sensor 161, 162, 163,
Writing signals from 164 and 165 and CPU1
Information is written during the calculation in step 54.

The ROM 153 is a read-only memory in which information necessary for arithmetic processing by the CPU 154 is stored in advance, and is read-only from the CPU 15 as necessary.
It is read from 4.

The CPU 154 is a device that performs arithmetic processing on various input information according to predetermined processing conditions, and processes input information in creep control and starting clutch control.

The clock circuit 155 is a circuit that sets the calculation processing time of the CPU 154.

The output circuit 156 is a circuit that outputs a control current value signal (c) to the solenoid 14, which is an actuator, based on the hydrochloric acid result signal from the CPU 154.

The shift switch 161 is a switch that detects whether the shift position of the automatic transmission is in the driving range and outputs a switch signal (p). If the shift position of the automatic transmission is in the driving range, an ON signal is output.

The idle switch 162 is a switch that detects whether the engine throttle is fully closed (idle state) and outputs a switch signal (i). If the engine is in idle state, an ON signal is output.
When the throttle is open, an OFF signal is output.

The output shaft rotational speed sensor 163 is a sensor that detects the rotational speed No. of the transmission output shaft 23, and outputs a rotational speed signal (no), which is used as a signal representing the vehicle speed Vsp.

The engine rotation speed sensor 164 is a sensor that detects the rotation speed N _E of the drive input shaft 17, and outputs a rotation speed signal (ne).

The turbine rotation speed sensor 165 is a sensor that detects the rotation speed N _T of the drive output shaft 22, and outputs a rotation speed signal (nt).

In the creep control, the engine rotation speed sensor 164 and the turbine rotation speed sensor 165 do not reduce the engagement pressure of the starting clutch 12 to completely zero, but instead maintain an engagement pressure state (half engagement state) in which the engagement pressure of the starting clutch 12 does not reach the level of clutch engagement. By performing control such that both sensors 164 and 1
65 is used as an input signal to determine the output current value I _FWD so as to obtain a predetermined slip rate (lower limit value required for creep prevention) by observing the rotational speed difference (N _E −N _T ).

Further, in the starting clutch control, the turbine rotation speed sensor 165 sets the output current value I FWD to the maximum value I _FULL at the start of the control, and sets the output current value I _FWD to the maximum value I _FULL .
A sensor used to determine how long to maintain
Due to the turbine rotational speed _NTS immediately before the idle switch 162 is turned OFF and the preset rotational speed reduction setting value α, the turbine rotational speed N _T based on the detection signal is smaller than _{NTS −α (NT < NTS} −α)
During this period, that is, from the start of the start until the turbine rotational speed N _T decreases by the set value α, the output current value I _FWD based on the maximum value I _FULL is output to the solenoid 14 .

The engine speed sensor 164 outputs an output current value at a maximum value I _FULL in starting clutch control.
After outputting I _FWD , it is used as a sensor to estimate the engine output in order to obtain the output current value I _FWD at which the clutch engagement pressure corresponding to the engine output is obtained.
As shown in FIG. 4, the ROM 153 stores in advance the engine speed N _E and the current value I _S as a control map M, and by looking up the table from this control map M, the engine speed N _E is determined. The current value I _M corresponding to is the output current value I _FWD .

Next, the operation of the embodiment will be explained.

First, the operation of the control device in the example will be explained in the fifth section.
This will be explained with reference to the flowchart shown in the figure.

(a) Creep prevention control This creep prevention control is performed by progressing the steps from step 100 → step 101 → step 102 → step 103 → step 104 → step 105 → step 106. Incidentally, step 104 is a step in which a signal 0 is written in FLAG1 of the RAM 152 as information indicating that creep control has been performed.

Step 105 is a step in which the engine speed N _E and the turbine speed N _T are temporarily stored as N _{ES and} N _TS , respectively. This is the reference value for the decrease of the number N _E.

In other words, creep control is performed when the vehicle is in the driving range (step 100), the throttle is fully closed (step 101), and the vehicle speed Vsp is zero (step 100).
102) Under the conditions, starting clutch 12
is brought into a semi-engaged state to reduce the torque transmitted to the transmission output shaft 23, thereby preventing the creep phenomenon.

In addition, in this creep prevention control, the engine rotation speed from the engine rotation speed sensor 164
N _E and the turbine rotation speed N _T from the turbine rotation speed sensor 165, the output current value I _FWD of the control current signal (c) is set by the control unit 15 so that the degree of engagement of the starting clutch 12 necessary to prevent creep is obtained. output from (step
106) Next, cases in which creep prevention control is not performed are listed.

If it is not the driving range but the neutral range or parking range.

The flow of operation in this case is step 100 → step 107 → step 106, and the output current value I _FWD =
A control current value signal (c) of 0 is output.

The vehicle is in the driving range, but the throttle is not fully closed (during normal driving).

The flow of operation in this case is step 100 →
Step 101→Step 108→Step 106, and normally the control current value signal (c) with the maximum value I _FULL is output.

(b) Creep control release When the idle switch 162 turns OFF,
That is, when the accelerator pedal is depressed to enter the starting position, the engagement pressure control of the starting clutch 12 is started.

(c) Starting clutch control This starting clutch control includes starting clutch control after creep prevention control, and starting clutch control in which creep prevention control is not performed, such as after stopping at the neutral position and immediately after the select operation to the drive position. Divided into.

In the case of starting after creep prevention control, the flow of operation is from step 100 → step 101 → from the time of start until the turbine rotational speed N _T decreases by the rotational speed reduction set value α.
Step 102 → Step 109 → Step 110 →
Repeat step 111 → step 106, and when the set value α is exceeded, step 100 → step 101 →
Step 102 → Step 109 → Step 110 →
Step 112→Step 113→Step 106.

In this way, if it is determined in step 109 that the creep prevention control has been performed, and the turbine rotational speed N _T has not decreased to the set value α, the control current value signal (c) based on the maximum current value I _FULL is is output, and when the set value α is exceeded, a control current value signal (c) based on a current value I _S corresponding to the engine rotation speed N _E is output.

When starting without creep prevention control, the operation flow is from step 100 to step 101.
→ Step 102 → Step 109 → Step 112
→ Step 113 → Step 106 is repeated, and the current value I _S according to the engine speed N _E is
A control current value signal (c) is output.

Among the starting clutch controls described above, the starting clutch control after the creep prevention control is performed as shown in the time chart of FIG.

First, the switch signal of the idle switch 162
Starting clutch control starts from the moment when (i) becomes an OFF signal, and by outputting the maximum current value I _FULL at the initial stage, there is almost no delay in reducing the turbine rotation speed N _T and the starting response is improved. It can be seen that it is in good condition.

After that, the clutch pressure is controlled by the output current value I _FWD according to the engine speed N _E , so that the starting clutch 12 is smoothly engaged, and from the time chart of the output shaft torque T. As can be seen, a good starting condition with little torque fluctuation can be obtained.

Note that the output time of the maximum current value I _FULL will be shorter if the engine speed N _E before the clutch is engaged is low and the turbine speed N _T is rapidly decreasing; The number N _E is high;
If the turbine speed N _T decreases slowly, the time is controlled so that it becomes _longer . There is no possibility of clutch slippage or tightening shock due to variations in temperature.

In this way, in the starting clutch control device of the embodiment, the control current value signal that provides the maximum clutch engagement pressure is maintained from the start of the start until the turbine rotational speed N _E decreases by the rotational speed reduction set value α. , and then outputs a control current value signal that obtains a clutch engagement pressure according to the engine speed N _E , so a starting system is established with no delay in hydraulic response in the initial stage of starting, and after that, By gradually increasing the clutch engagement force, smooth engagement control of the starting clutch can be performed.

The output time of the maximum current value I _FULL at the initial stage of starting is set by the decrease in the turbine rotation speed N _E , so the throttle opening at the time of starting,
Regardless of clutch variations, oil temperature differences, etc., it is possible to always maintain approximately the same starting system.

Next, other embodiments shown in FIGS. 7 and 8 will be described.

This embodiment is the same as the previous embodiment in that in the starting clutch control, the maximum current value I _FULL is temporarily output from the start of the start.
After that, the starting clutch 12 is activated according to the engine output.
This is an example in which the clutch engagement pressure control is performed so that the output current value I _FWD is determined in accordance with the engine speed difference ΔN _E between the engine speeds N _E and not the engine speed N _E itself.

In FIG. 8, steps that are the same as those in the flowchart explained in the previous embodiment are given the same reference numerals, and different steps will be explained.
= 0, and the value of the output current value I _FWD output to the solenoid 14 at that time in step 115 is stored as I _C.

On the other hand, during starting clutch control, it is determined in step 116 whether FLAG2 = 1, and since FLAG2 = 0 in the first flow, the process advances to step 117. In step 117, the output current value I _FWD is determined. I _C
Determined by +ΔI, FLAG2=1 at step 118
In step 106, the control current value signal (c) based on I _FWD determined by the above calculation is output.

Incidentally, the current value increase ΔI is obtained by table lookup from a map preset in the control unit 15, as shown in FIG.

If it is determined in step 116 that FLAG2=1 (the working flow is from the second time onwards), the process proceeds to step 119, where the engine speed difference ΔN _E (corresponding to the increase in engine speed N _E ) is calculated. Then, in step 120, the engine speed difference ΔN _E is multiplied by a coefficient K, and this value is added to the previous I _FWD and output as the current output current value I _FWD in step 106.

Note that the engine speed difference ΔN _E is ΔN _E =N _E
-NES is calculated, and the increase in engine speed is determined based on the engine speed _NES immediately before starting clutch control starts.

Therefore, in this embodiment, while the current value during creep prevention control changes due to variations in oil temperature, clutch, etc., the current value is increased by the increase in engine output based on the previous current value. By doing so, it is possible to always have a good response and a smooth start.

Although the embodiments of the present invention have been described above in detail with reference to the drawings, the specific configuration is not limited to these embodiments, and the present invention may be modified without departing from the gist of the present invention. included.

For example, in the embodiment, a fixed established value is used as the rotational speed reduction set value α, but it can be made variable depending on operating conditions such as oil temperature, accelerator opening, and engine rotational speed.

In addition, although the embodiment shows a creep prevention control device that leaves a slight tightening pressure during creep prevention control, it is of course possible to apply it to a creep control device that reduces the tightening pressure to zero, as in the conventional example. It is.

Further, in the embodiment, an example of hydraulic pressure control using current value control is shown, but it may also be based on duty control, or hydraulic pressure control may be based on variable hydraulic pressure obtained by directly controlling the hydraulic pressure supplied to the starting clutch. Good too.

In addition, in the embodiment, an example was shown in which a signal corresponding to the engine output after the maximum current value is output is set using the engine rotation speed, but as a signal corresponding to the engine output, a throttle opening signal, an intake air flow rate signal to the engine, etc. This may be done by estimating the engine output using , or some other method may be used.

(Effects of the Invention) As explained above, in the starting clutch control device of the present invention, the control means maintains the clutch engagement pressure at or near the maximum from the start of the start until the turbine rotational speed decreases by a predetermined value. By outputting a control signal that obtains a clutch engagement pressure that corresponds to the engine output, this method is able to respond to the starting throttle opening while providing a temporary A signal output that provides the maximum or near-maximum clutch engagement pressure provides a starting system with no delay in hydraulic response, and after that, it is possible to perform starting clutch control that gradually increases the clutch engagement force in accordance with the engine output. This effect can be obtained.

Due to this effect, smooth starting can be performed without causing clutch slippage or engagement shock during starting.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of a claim showing a starting clutch control device for an automatic transmission according to the present invention, Fig. 2 is an overall view showing a starting clutch control device of an embodiment, and Fig. 3 is an output of OPM current value of the embodiment device. FIG. 4 is a relationship diagram showing the relationship with port pressure, FIG. 4 is a relationship diagram between engine speed and current value stored in advance in the control unit in the embodiment device, and FIG. FIG. 6 is a time chart of starting clutch control in the embodiment device;
FIG. 7 is a relationship diagram between engine speed and current value increase in another example of starting clutch control, and FIG. 8 is a flowchart showing the flow of operation in another starting clutch control. 1...Liquid coupling, 2...Starting clutch, 3...
Hydraulic supply path, 4... fastening pressure control means, 6
...Input sensor, 601... Turbine rotation speed sensor, 602... Engine output sensor, 7... Control means.

Claims (1)

[Scope of Claims] 1. A starting clutch that is tightened by supplying hydraulic pressure and into which engine driving force is input via a fluid coupling;
an engagement pressure control means for controlling the engagement pressure of the starting clutch provided in a hydraulic pressure supply path to the starting clutch; and a control signal for increasing the clutch engagement pressure when a signal indicating the time of starting is inputted from the input sensor to the engagement pressure. A starting clutch control device for an automatic transmission, comprising: a control means for outputting an output to the control means, wherein the input sensor includes a turbine rotation speed sensor for detecting the turbine rotation speed of the fluid coupling; The control means includes an engine output sensor that indirectly detects the engine output, and outputs a control signal that allows a clutch engagement pressure close to the maximum to be obtained from the start of the start until the turbine rotation speed decreases by a predetermined value, and thereafter 1. A starting clutch control device for an automatic transmission, characterized in that the starting clutch control device for an automatic transmission is configured as a means for outputting a control signal for obtaining a clutch engagement pressure according to an engine output.