JPS62181926A - Advance clutch control device for automatic speed changer - Google Patents

Abstract

PURPOSE:To allow a smooth advance by controlling so as to obtain the maximum clutch tightening pressure after the start of the advance until the turbine rotating speed of a fluid coupling is decreased by a predetermined value then obtain the clutch tightening pressure in response to the engine output. CONSTITUTION:The said device has an advance clutch 2 fed with an engine drive force via a fluid coupling (torque converter) 1 and controls its clutch tightening pressure via a tightening pressure control means 4 provided on a hydraulic pressure feed passage 3. In this case, the control means 7 is constituted so as to output a control signal to obtain the maximum or near maximum clutch tightening pressure after the start of the advance until the turbine rotating speed detected by a rotating speed sensor 601 is decreased by a predetermined value then output a control signal to obtain the clutch tightening pressure in response to the engine output.

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 Unexamined Patent Publication No. 13156/1983 is known.

In this conventional device, a discharge oil passage leading to a sleeve tank is branched from a supply oil passage that supplies hydraulic pressure to the starting clutch of the automatic transmission and other starting devices, and this discharge oil passage is closed in a demagnetized state and is in an energized state. In a creep prevention device including a solenoid valve that is opened, the energizing circuit of the solenoid valve is primed 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 by chopping control (control that repeats 0N-OFF according to a set time and is the same as duty control). This was intended to prevent the shock caused by sudden tightening when starting.

The creep phenomenon is a phenomenon that occurs when a vehicle equipped with an automatic transmission is left in the running position (particularly a position with a large gear ratio) while the vehicle is stopped. A creep prevention device is a phenomenon in which a vehicle tries to move forward or backward, and a creep prevention device is a device that is engaged when the automatic transmission is in a neutral state, a low gear ratio state, or a driving position under conditions where the creep phenomenon 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, in 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 rotational speed before engagement of the first starting clutch was different.

For example, if the setting was set to prevent clutch slippage or shock from occurring at a medium throttle opening when starting, the clutch would slip at a high throttle opening and the start would be delayed. On the other hand, when the throttle opening is low, the clutch is suddenly engaged, causing 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. 1. A starting clutch 2 is engaged by supplying hydraulic pressure and receives engine driving force through a fluid coupling l;
engagement pressure control means 4 provided in the hydraulic pressure supply path 3 to the starting clutch 2 and controlling the engagement pressure of the starting clutch;
and a control means 7 that outputs a control signal to gradually increase the clutch engagement pressure to the engagement pressure control means 4 when a signal indicating the time of starting is inputted from the input sensor 6. In the control device, the input sensor 6 includes a turbine rotation speed sensor 601 that detects the turbine rotation speed of the fluid coupling 1, and an engine output sensor 6 that directly or indirectly detects the engine drive output.
02, the control means 7 outputs a control signal that obtains the maximum or near maximum clutch engagement pressure from the start of the first start until the turbine rotational speed decreases by a predetermined value, and then outputs a control signal that obtains the clutch engagement pressure at or near the maximum, and thereafter engages the clutch in accordance with the engine output. This is a means of outputting a control signal to obtain pressure.

(Function) Therefore, in the starting clutch control device of the present invention, as described above, the control means is controlled so that the clutch engagement pressure at or near the maximum is obtained from the start of the start until the turbine rotational speed decreases by a predetermined value. By using a means of outputting a signal and then outputting a control signal that obtains a clutch engagement pressure according to the engine output, the signal output can temporarily obtain the maximum or near maximum clutch engagement pressure at the initial stage of starting. Once a starting system with no delay in hydraulic response is established, starting clutch control can be performed in which the clutch engagement force gradually increases in accordance with the engine output.

The temporary signal output time at the beginning of the start is set from the start of the start until the turbine rotation speed decreases by a predetermined value, making it responsive to the start throttle opening.
For example, when starting from a low throttle opening and the engine speed is low before clutch engagement, the signal output time to obtain the maximum or near maximum clutch engagement pressure is short, and shocks caused by sudden latch engagement can be prevented. If the engine speed is high before the clutch is engaged when starting from a high throttle opening, on the other hand, the signal output time is long, and slipping of the starting clutch can be prevented.

(Example) Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

In describing this embodiment, a starting clutch control device for an automatic transmission equipped with a creep prevention device that performs a control operation after creep prevention is released will be taken as an example.

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. It is equipped with an input sensor 16 and will be described below.
Each configuration will be described.

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. Impeller 1
8, 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. The drive output shaft 22 is connected to the drive output shaft 22 .

The starting clutch 12 engages gear elements of a gear train such as planetary gears of an automatic transmission.

This clutch is provided to transmit the driving force from the drive output shaft 22 to the mission output shaft 23 at the time of starting, and includes a clutch drum 24 connected to the drive output shaft 22, and a clutch drum 24 connected to the drive output shaft 22. A clutch plate 25 is provided, a clutch hub 27 is provided with clutch plates 26 arranged at alternate positions, a clutch piston 28 is provided on the clutch hub 27 side, and the clutch piston 28 is A piston chamber 29 is supplied with control hydraulic pressure Pc for operation.

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

The oil pressure modulator (hereinafter abbreviated as OPM) 13 is installed in the middle of a line pressure oil path 30 to which line pressure Pt, which is the discharge pressure from the oil pump regulated by a pressure regulator valve, is supplied. (in the control valve unit of an automatic transmission, etc.), this OPM 13 and the piston chamber 29 of the starting clutch 12
and 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 boat pressure increases according to the current value to the solenoid 14 (see Figure 3). The body 32 has a spool 33. Control pressure input boat 34. Control pressure output port 35
．． Drain port 1-36, tire flam 37. Spool operating piston 38. Air chamber 39. Communication path 40. A pressure oil chamber 41 and a solenoid 14 are provided, and the electromagnetic force by the solenoid 14 (force pushing the spool 33 to the left in the drawing) and the hydraulic pressure by the pressure oil chamber 41 (force pushing the spool 33 to the right in the drawing) are combined. The spool 33 is actuated by the balance, and the control pressure from the output port 35 is determined by the degree of opening and closing of the drain boat 36.

The above control unit ) 15 uses an in-vehicle microcomputer, and has an input circuit 1 as an internal circuit.
51. RAM (random, access, memory) 152,
ROM (read, only, memory) 153, CPU
(central, processing, unit) 154, a clock circuit 155, and an output circuit 156.

The human power sensor 16 includes a shift switch 161,
Idle switch 162, output shaft rotation speed sensor 163,
Engine speed sensor 164, turbine speed sensor 1
65 are provided.

The input circuit 151 receives signals (p), (i), (no), and (ne) from the input sensor 16.

(nt) into a digital signal that can be processed by the CPU 154.

The RAM 152 is a readable and writable memory, and has data for each sensor 161, 162, 163°164.16.
Signal writing from CPU 154 and information writing during calculation by CPU 154 are performed.

The ROM 153 is a read-only memory,
Information necessary for arithmetic processing by the CPU 154 is stored in advance, and is read out from the CPU 154 as needed.

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 a calculation 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), and outputs an ON signal if the automatic transmission is in the driving range.

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 throttle is in the idle state, an ON signal is output and the throttle is opened. When it is present, an OFF signal is output.

The output shaft rotation speed sensor 163 is connected to the mission output shaft 2.
The rotation speed signal (no
) is output, and this signal (no) is used as a signal indicating 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 receives a rotation speed signal (ne
) is output.

The turbine rotation speed sensor 165 is a sensor that detects the rotation speed NT 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 completely reduce the engagement pressure of the starting clutch 12 to 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. With this control, when creep control is activated, both sensors 164 and 165 monitor the rotational speed difference (NE-NT) so that a predetermined slip ratio (lower limit value required for creep prevention) is obtained. It is used as an input signal for determining the output current value IFW.

Further, in the starting clutch control, the turbine rotation speed sensor 165 sets the output current value IFWD to the maximum value IPULL at the start of the control, and sets the output current value IFWD to the maximum value IPULL.
This sensor is used to determine the time period for which the turbine rotation speed NTS is maintained, and the turbine rotation speed NT determined by the detection signal is determined by the turbine rotation speed NTS immediately before the idle switch 162 is turned OFF and a preset rotation speed reduction setting value α. While it is smaller than α (NT<NTs-α), that is, from the start of the start until the turbine rotation speed NT decreases by the set value α,
An output current value IpWO based on the maximum value IPULL is output to the solenoid 14.

In the starting clutch control, the engine rotation speed sensor 164 outputs an output current value Ipwn based on the maximum value IFULL.
15(7) The ROMI 53 includes a As shown in Figure 4, the engine speed NE and current value IS are stored in advance as a control map M, and by table lookup from this control map M, the current value Is corresponding to the engine speed NH is output. The current value becomes Ipwo.

Next, the operation of the embodiment will be explained.

First, the operation of the control device in the embodiment will be explained with reference to the flowchart shown in FIG.

(a) Creep prevention control This creep prevention control is performed from step 100 to step 1.
01 → Step 102 → Step 103 → Step 10
4→Step 105→Step 1O6.

Incidentally, step 104 is a step in which a signal O is written in FLAGl of the RAM 152 as information indicating that creep m control has been performed.

Step 105 is a step in which the engine rotation speed NE and the turbine rotation speed NT are temporarily stored as NEs and NTS, respectively, and the Nrs stored at the time of entering the start state is the reference for reducing the turbine rotation speed NH. value.

In other words, the creep control is in the driving range (step 100) and the throttle is fully open (step 101).
) is carried out under the condition that the vehicle speed Vsp is zero (step 102), and the starting clutch 12 is brought into a half-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 N! from the engine rotation speed sensor 164! and the turbine rotation speed Nr from the turbine rotation speed sensor 165, and the output current value IFWD of the control current signal (C) is outputted from the control unit 15 so that the degree of engagement of the starting clutch 12 necessary for creep prevention is obtained. (Step 1
06) Next, cases in which creep prevention control is not performed are listed.

■ When the vehicle is in the neutral range or parking range instead of the driving range.

The flow of operation in this case is step 100 → step 1
07→Step 106, output current value Ipwo=O
A control current value signal (C) 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 1
01 → Step 108 → Step 106 1 Normally,
A control current value signal (C) based on the maximum value IFULL is output.

(b) When the creep control release idle switch 162 is turned OFF, that is, when the accelerator pedal is depressed and the start system is entered,
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.

■ When starting after creep prevention control, the flow of operation is as follows: First, from the start of the first start, the turbine rotation speed N
Step 100 → Step 101 → Step 102 → Step 1 until T decreases by the rotational speed reduction set value α.
09 → Step 110 → Step 111 → Step IO
Repeat step 6, and if the set value α is exceeded, proceed to step 10.0→
Step lot → step 102 → step 109 → step 110 → step 112 → step 113 → step 106.

In this way, when it is determined in step 109 that the creep prevention control has been performed, and the turbine rotation speed Nr has not decreased to the set value α, the control current value signal (C) based on the maximum current value IFDLL is output. When the set value α is exceeded, a control current value signal (C) based on the current value Is corresponding to the engine speed NH is output.

■ The flow of operation when starting without creep prevention control is as follows.
Repeat the flow of step 100 → step 101 → step 102 → step 109 → step 112 → step 113 → step 106 until the engine speed NH
A control current value signal (e) based on the current value Is corresponding to the current value Is 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. 6.

First, starting clutch control is started from the time when the switch signal (i) of the idle switch 162 becomes an OFF signal, and by outputting the maximum current value ■FULL at the initial stage, the delay in the decrease in the turbine rotational speed NT is reduced. Almost 1
It can be seen that the starting response is good.

Thereafter, the clutch pressure is controlled by the output current value Ipwo according to the engine speed Nv, so that the clutch engagement of the starting clutch 12 is performed smoothly, 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 IFULL is determined when the engine speed Ng is low before the clutch is engaged and the turbine speed Ng is low.
The time is controlled in such a way that if T falls rapidly, the time becomes shorter, and conversely, if the engine speed NU before clutch engagement is high and the turbine speed NT falls slowly, the time becomes longer. For example, the maximum current value Iput
Unlike the case where the output times of , t, and the like are determined by a timer or the like, clutch slippage and engagement shock do not occur due to variations in the starting clutch 12 or oil temperature.

In this way, the starting clutch control device of the embodiment has a control current value signal that provides the maximum clutch engagement pressure from the start of one start until the turbine rotational speed NE decreases by the rotational speed reduction set value α. , and then outputs a control current value signal that obtains the clutch engagement pressure according to the engine speed NH, so a starting system with no delay in hydraulic response is established at the beginning of the start, and then gradually It is possible to increase the clutch engagement force and perform smooth engagement control of the starting clutch.

Since the output time of the maximum current value IFULL at the initial stage of starting is set according to the decrease in the turbine rotation speed NH, it is independent of the throttle opening at the time of starting, clutch variations, oil temperature differences, etc. , it is possible to always maintain almost 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 the maximum current value IpuLt is temporarily output from the start of the start in the 1-start clutch control, but after that, the start clutch 12 is This is an example in which the clutch engagement pressure control is performed so that the output current value IpwD is determined not according to the engine speed NE itself, but according to the engine speed difference ΔNH between the engine speeds NE.

In FIG. 8, the same steps as in the flowchart diagram explained in the above embodiment are given the same reference numerals, and different steps will be explained. At the time of creep prevention control, FLAG2 is set to O in step 114, and The output current value Ipw output to the solenoid 14 at that time in step 115.

The value of is stored as Ic.

On the other hand, during starting clutch control, step 116
It is determined whether FLAG2=1 or not, and since FLAG2=O at the time of the first flow, the process proceeds to step 117, and in this step l17, the output current value Ipwo is set to Ic+Δ
I is determined by I, rewritten to FLAG2=1 in step 118, and I determined by the calculation in step 106.
pw.

A control current value signal (C) is output.

Incidentally, the current value increase ΔI is determined 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 ΔNg (corresponding to the increase in engine speed Ng) is calculated. , then
In step 120, the engine speed difference ΔNE is multiplied by a coefficient K, and this value is added to the previous Ipwo and output as the current output current value Ipwo in step 106.

Note that the engine speed difference ΔNE is ΔNE=NE−N
The engine speed increase is calculated using ES and is based on the engine speed NES immediately before starting clutch control.

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 good response and 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 setting value is used as the rotational speed reduction setting value α, but it can be varied 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 was shown, but it may also be based on duty control, or hydraulic pressure control may be performed using variable hydraulic pressure obtained by directly controlling the hydraulic pressure supplied to the starting clutch. .

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

(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 the maximum or near 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 and then outputting a control signal that obtains a clutch engagement pressure that corresponds to the engine output, it is responsive to the starting throttle opening while providing temporary control at the initial stage of starting. A signal output that provides maximum or near-maximum clutch engagement pressure establishes a starting system with no delay in hydraulic response, and after that, it is possible to perform starting clutch control that gradually increases clutch engagement force in accordance with engine output. This effect can be obtained.

Due to this effect, it is possible to smoothly start the vehicle without clutch slippage or engagement shock when the vehicle starts.

[Brief explanation of drawings]

Fig. 1 is a conceptual diagram of a claim showing a starting clutch control device for an automatic transmission of 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 relational diagram showing the relationship with boat pressure; FIG. 4 is a relational diagram between engine speed and current value stored in advance in the control unit of the embodiment device; FIG. 6 is a time chart of starting clutch control in the embodiment device, and FIG. 7 is a relationship diagram between engine speed and current value increase in another example of starting clutch control. , FIG. 8 is a flowchart showing the flow of operation in another starting clutch control. 1... Fluid bare hand 2... Starting clutch 3... Hydraulic pressure supply path 4... Engagement pressure control means 6... Input sensor 601... Turbine rotation speed sensor 602... Engine output sensor 7. ... Control means patent application Nissan Motor Co., Ltd.

Claims (1)

[Scope of Claims] 1) A starting clutch that is engaged by supplying hydraulic pressure and into which engine driving force is input via a fluid coupling, and a starting clutch that is provided in a hydraulic pressure supply path to the starting clutch and controls the engagement pressure of the starting clutch. A starting clutch for an automatic transmission, comprising: an engagement pressure control means for controlling the engagement pressure, and a control means for outputting a control signal for increasing the clutch engagement pressure to the engagement pressure control means when a signal indicating the time of starting is inputted from an input sensor. In the control device, the input sensor includes a turbine rotation speed sensor that detects the turbine rotation speed of the fluid coupling, and an engine output sensor that directly or indirectly detects the engine drive output,
The control means outputs 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 thereafter, a clutch engagement pressure that corresponds to the engine output is obtained. A starting clutch control device for an automatic transmission, characterized in that the device is a means for outputting a control signal.