JPH01101240A - Vehicle clutch control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A.Objective of the invention (industrial application field) The present invention is directed to the control of a clutch means that controls the amount (degree of transmission) of power transmitted from an engine to wheels via a transmission. Regarding the method.

(Prior Art) Various types of clutch means have been used in the past, such as a type using a friction clutch disk.

To give an example, there is a clutch device disclosed in Japanese Unexamined Patent Application Publication No. 56-95722, and in this device,
A short-circuit path is formed between two oil paths that connect a hydraulic pump and a hydraulic motor to form a closed circuit, and a clutch valve whose opening degree can be adjusted is placed in this short-circuit path, and the operation of this clutch valve is controlled. A first detection means for detecting the engine rotation speed and a second detection means for detecting the throttle opening are connected to the control device, and the control device controls the engine to drive the clutch valve in the closing direction. The clutch valve is configured to exert a control force proportional to the rotational speed and a control force proportional to the throttle opening degree to drive the clutch valve in the opening direction.

That is, in the clutch device described above, a target engine speed is set in accordance with the throttle opening, and the clutch opening is controlled so that the actual engine speed matches the target engine speed. ing.

(Problems to be Solved by the Invention) By the way, in order to prevent the engine speed from increasing more than necessary due to an increase in engine output when starting a vehicle, that is, to prevent the engine from revving up, there are 1. When the engine is idling, it is necessary to appropriately select and control the opening of the short circuit, that is, the opening of the clutch valve, so that the initial load of the engine is appropriate. However, when the accelerator pedal is suddenly depressed to start the vehicle, a signal to increase the throttle opening according to the amount of depression of the accelerator pedal is immediately input to the control device. Since there is a slight time delay in increasing the engine speed, the engine speed increase signal is input to the control device with a slight delay. Therefore, momentarily, even though the throttle opening is large and the target engine speed is high, a state occurs where the engine speed has not yet risen. is controlled so that it is in the opening direction. As a result, the load on the engine becomes too small and the engine speed exceeds the target engine speed and increases more than necessary. Moreover, as this increased engine speed is input to the control device, the clutch valve is suddenly operated in the closing direction, making it impossible to obtain an appropriate half-clutch state, causing hunting and other problems in the vehicle. There is a problem in that smooth one-start movement of the vehicle is obstructed.

SUMMARY OF THE INVENTION In view of these problems, it is an object of the present invention to provide a latch control method that enables smooth starting and stopping of a vehicle.

1. Structure of the Invention (Means for Solving the Problem) As a means to achieve the above object, the control method of the present invention provides a method for controlling the vehicle speed and the accelerator opening (a value corresponding to the amount of depression of the accelerator pedal or a value corresponding to the amount of depression of the accelerator pedal). A target opening degree of the clutch means is set in correspondence with the throttle opening degree (to be interlocked), and the degree of power transmission by the clutch means is controlled by making the opening degree of the clutch means match the target opening degree. It looks like this.

(Function) If the clutch opening is controlled using the control method with the above configuration, the clutch opening will be controlled using only the accelerator opening and vehicle speed as control information, and the engine response will not be very good. Since the rotation speed is not used as control information for the clutch opening degree, it is possible to avoid inappropriate control of the latch opening degree due to a delay in the rise of the engine rotation speed when the accelerator pedal is suddenly depressed as described above. It will be done.

This prevents the engine from speeding up when starting the vehicle and from hunting due to an inappropriately partially engaged clutch.

(Embodiments) Hereinafter, preferred embodiments of the present invention will be described based on the drawings.

FIG. 1 shows a hydraulic circuit of a hydraulic continuously variable transmission whose clutch opening is controlled by the method of the present invention, and the continuously variable transmission T is a constant displacement type driven by an engine E via an input shaft 1. It has a hydraulic pump P and a variable displacement hydraulic motor M having an output shaft 2 that drives wheels W. These hydraulic pump P and hydraulic motor M have a first oil passage La that communicates the discharge port of the pump P and the suction port of the motor M, and a second oil passage L that communicates the suction port of the pump P and the discharge port of the motor M.
The two oil passages with b constitute a hydraulic closed circuit and are connected to each other.

In addition, a charge pump 10 driven by the engine E
A charge oil passage L whose discharge port has a check valve 11
h and a third oil passage Lc having a pair of check valves 3.3, the hydraulic oil is pumped up from the oil sump 15 by the charge pump 10 and pressure regulated by the charge pressure relief valve 12. Due to the action of the check valves 3, 3, the two oil passages 1. a,
It is supplied to the oil passage on the low pressure side of Lb. Further, a fourth oil passage Ld having a shuttle valve 4 to which fifth and sixth oil passages Le and Lf connected to the oil sump 15 and having high pressure and low pressure relief valves 6.7 is connected to the closed circuit. ing. This shuttle valve 4 is a two-bottom, three-position switching valve that operates according to the oil pressure difference between the first and second oil passages La, Lb.
Among them, the oil passage on the high pressure side is communicated with the fifth oil passage Le, and the oil passage on the low pressure side is communicated with the sixth oil passage Lf. As a result, the relief oil pressure in the oil passage on the high pressure side is increased by the high pressure relief valve 6.
The relief oil pressure in the oil passage on the low pressure side is regulated by the low pressure relief valve 7.

Furthermore, a seventh oil passage Lg is provided between the first and second oil passages La and Lb, and this seventh oil passage Lg short-circuits both oil passages.
A clutch valve 5 consisting of a variable throttle valve that controls the opening degree of this oil passage is disposed in the oil passage Lg. Therefore, by controlling the throttle amount of the clutch valve 5, it is possible to perform clutch opening degree control that controls the transmission of driving force from the hydraulic pump P to the hydraulic motor M.

Further, the engine E drives a hydraulic pump P, and the oil pressure from the hydraulic pump P rotationally drives a hydraulic motor M. This rotation is transmitted to the wheels W via the output shaft 2, and the wheels W are driven. However, the hydraulic motor M is, for example, a swash plate axial piston motor, and by controlling the angle of this swash plate, the gear ratio of the transmission T can be varied steplessly. Note that a description of the control of the swash plate angle will be omitted since it is well known.

On the other hand, the operation of the clutch valve 5 is controlled by a Kurasochi servo valve 80, and the operation of the clutch servo valve 80 is controlled by a pair of solenoid valves 155.
The controller 100 controlled by the controller 156 receives signals indicating the vehicle speed V, the engine speed Ne, the throttle opening θth, the swash plate tilt angle θtr of the hydraulic motor M, and the clutch opening θC1. Based on the signals, signals are outputted to control each of the solenoid valves so that desired travel control is performed.

Below, the structure and operation of the clutch servo valve 8o will be explained in detail with reference to FIG.

The valve 80 includes a cylinder member 81, a piston member 82 fitted into the cylinder member 81 so as to be slidable left and right in the figure, and a cover member attached to cover the cylinder chamber into which the piston member 82 is fitted. 85, and a spring 87 that urges the piston member i2 leftward in the figure. The piston 82a of the piston member 82 divides the cylinder chamber into two to form left and right cylinder chambers 83.84, and hydraulic lines 110, 112 are connected to both cylinder chambers 83.84 via boats 86a, 86b. .

The hydraulic pressure in the hydraulic line 110 is the hydraulic oil that is obtained by adjusting the pressure of the discharge oil of the charge pump 10 by the charge pressure relief valve 12 and is led through the hydraulic line 101. Two solenoid valves 1 whose duty ratio is controlled control the hydraulic pressure of a hydraulic line 111 having a branched orifice 111a.
55.156.

The solenoid valve 156 controls opening and closing of the flow rate of hydraulic oil from the hydraulic line 111 having the orifice 111a to the hydraulic line 112 according to the duty ratio.
The solenoid valve 155 is disposed between the hydraulic line 113 branching from the hydraulic line 112 and the hydraulic line 114 communicating with the drain side via the orifice 114a, and is operated from the hydraulic line 113 to the drain side according to a predetermined duty ratio. This is what causes oil to spill.

For this reason, the right cylinder chamber 52 is connected via the hydraulic line 110.
The charge pressure regulated by the charge pressure relief valve 12 acts on the left cylinder chamber 83 , but from the hydraulic line 112 , due to the operation of the two solenoid valves 155 and 156 , a pressure lower than the charge pressure is applied to the left cylinder chamber 83 . is supplied to Here, since the pressure receiving area of the right cylinder chamber 84 is smaller than the pressure receiving area of the left cylinder chamber 83, the force that the piston member 82 receives due to the hydraulic pressure in the left and right cylinder chambers 83, 84 is determined by taking into account the biasing force of the spring 87. The hydraulic pressure P1 in the right cylinder chamber 84 is balanced when the hydraulic pressure in the left cylinder chamber 83 is a predetermined value P2 (PL>P2) lower than this. Therefore, if the hydraulic pressure supplied from the hydraulic line 112 to the left cylinder chamber 83 is controlled by the solenoid valves 155 and 156 to be greater than the predetermined value P2, the piston member 82 can be moved to the right, and the left cylinder If the hydraulic pressure supplied to the chamber 83 is controlled to be smaller than P2, the piston member 82 can be moved to the left.

This movement of the piston member 82 in the left-right direction is transmitted to the clutch valve 5 via the link mechanism 88. The clutch valve 5 includes a fixed member 5a having a first valve hole 5b, and a second valve hole 5d rotatably disposed within the fixed member 5a.
An arm 5e connected to the rotating member 5C is connected to the link mechanism 88, and as the piston member 82 moves, the rotating member 5C
is rotated. When the rotating member 5C is rotated, the degree of communication between the first and second valve holes 5b and 5d changes from fully open to fully closed. As shown in the figure, the communication opening in the clutch valve 5 is fully opened when the piston member 82 is moved to the left to the maximum extent, and thereafter, as the piston member 82 is moved to the right, the communication opening is fully closed. It gradually changes until.

Here, the first valve hole 5b communicates with a first oil passage La that constitutes a closed circuit of the continuously variable transmission T, and the second valve hole 5d communicates with a second oil passage La that constitutes a closed circuit of the continuously variable transmission T.
Since it communicates with the oil passage Lb, by changing the degree of communication opening of the first and second valve holes 5b and 5d, the seventh oil passage is a short-circuit path between the first and second oil passages La and Lb. L
The opening degree of g can be changed, thereby controlling the clutch opening degree. That is, based on the signal from the controller 100, the solenoid valve 155.1
Clutch opening degree control is performed by controlling the duty ratio of 56.

Regarding the method of controlling the opening degree of the clutch valve 5 by controlling the duty ratio of the solenoid valves 155 and 156,
This will be explained in detail based on the flowchart in FIG.

This control starts by reading the accelerator opening θace from the amount of depression of the accelerator pedal or the throttle opening of the engine, and reading the vehicle speed V. Subsequently, a target clutch opening θclo corresponding to the accelerator opening θacc is calculated from the graph of FIG.

In Figure 4, the accelerator opening θacc (1)...θacc
(n), the target clutch opening degree θcl corresponds to the vehicle speed V.
o is preset, vehicle speed ■ and accelerator opening θ
When the acc is read, the target clutch opening θcl is set to ensure smooth latch connection.
o can be calculated. Note that the lower accelerator opening degree is θacc(1) when the throttle is fully closed, and as the number becomes thicker, the opening degree increases sequentially and becomes θacc(1).
n) indicates the throttle fully open state, and the target clutch opening θ
eta has its maximum value at 90° when fully closed,
As this value decreases, it changes to the open side, and when it is fully open, it is 0°.

Next, the actual clutch opening θC1 is read, and the target clutch opening θclo calculated above and the actual clutch opening θC are
! The opening difference ΔθC! (=θclo−θcl) is calculated. And this opening difference ΔθC! Based on the graph of FIG. 5, the clutch opening control speed is calculated. As is clear from FIG. 5, this control speed is controlled when the opening difference ΔθC1 is positive, that is, the target clutch opening θ
When clo is larger than the actual clutch opening θc1 (when the target clutch opening θclo is on the closing side), the direction of closing (turning on) a clutch proportional to the size of this opening difference Δθc1 When the control speed is given and the opening difference Δθcl is negative, that is, when the target clutch opening θclo is smaller than the actual clutch opening θC1 (when the target clutch opening θclo is on the open side)
is given a control speed in the direction of opening (turning OFF) the clutch proportional to the absolute cage size of this opening difference Δθc1.

Then, the opening/closing control of the clutch valve 5 is performed based on the speed calculated in this way, and as a result, the actual clutch opening θc is compared to the target clutch opening θclo.
When l is far apart, the actual clutch opening θC!
Opening control is performed at a fast control speed so that the actual clutch opening degree θclo rapidly approaches the target clutch opening degree θclo, and as the two approaches, the control speed becomes slower and the actual clutch opening degree θc1 is gradually brought closer to the target clutch opening degree θclo.

When controlling as described above, since the engine speed is not used as the control information, it is not affected by the delay in increasing the engine speed as in conventional control.
Even when the accelerator pedal is suddenly operated, the latch can be turned on and off smoothly.

In addition, in the above embodiment, a method of controlling the opening of a clutch valve that controls the opening of a short-circuit path that short-circuits a closed circuit in a hydraulic transmission consisting of a hydraulic pump and a hydraulic motor will be described. However, the control method of the present invention is not limited to such a method, and can be applied to a clutch device using a friction clutch as in other types of transmissions such as a conventionally used gear type transmission. can also be used.

C1 As described in detail of the invention, according to the method of the present invention, the target opening of the clutch means is set in accordance with the vehicle speed and the accelerator opening, and the opening of the clutch means is adjusted to the target opening. The degree of power transmission by this clutch means is controlled so that the degree of power transmission by this clutch means matches the degree of opening of the accelerator pedal. Inappropriate control of the latch opening due to a delay in the increase in engine speed when the engine speed is suddenly depressed can be avoided. Hunting can be prevented from occurring due to an appropriate half-clutch.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram of a continuously variable transmission in which the clutch opening degree is controlled by the method of the present invention, and Fig. 2 is a sectional view of a clutch servo valve that controls the clutch opening degree of the continuously variable transmission. Figure 3 is a flowchart showing the contents of clutch opening control according to the present invention, Figure 4 is a graph showing the relationship between vehicle speed and target clutch opening for each accelerator opening, and Figure 5 is a graph showing the relationship between clutch opening and clutch opening. It is a graph showing the relationship with opening control speed. 4...Shuttle valve 5...Clutch valve 10.
...Charge pump 80...Clutch servo valve 155.156...Solenoid valve 100...Controller E...Engine T...Continuously variable transmission
W...Wheel Figure 3 Figure 4 Figure 5

Claims (1)

[Scope of Claims] 1) A vehicle comprising a transmission that changes the speed and transmits engine output to wheels to drive the wheels, and a clutch means that controls the degree of transmission of the engine output by the transmission. , a target opening degree of the clutch means is set in accordance with a vehicle speed and an accelerator opening degree of the vehicle, and the degree of transmission is controlled by making the opening degree of the clutch means coincide with the target opening degree. Characteristic vehicle clutch control method. 2) The transmission is a hydraulic continuously variable transmission including a hydraulic pump, a hydraulic motor, and a hydraulic closed circuit connecting the hydraulic pump and the hydraulic motor, and the clutch means is configured to short-circuit the hydraulic closed circuit. 2. The method of controlling a clutch for a vehicle according to claim 1, wherein the clutch valve is disposed in a road and adjusts the opening degree of the short-circuit road.