JPH0674014B2 - Control method for starting clutch - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for controlling a starting clutch which is provided between an engine and a transmission and which automatically performs starting control.

Conventional technology and its problems Conventionally, automatic clutches such as electromagnetic clutches and fluid clutches are known as starting clutches that can automatically perform start control, but in the case of electromagnetic clutches, the structure is complicated and expensive. In addition, the liquid clutch has excellent starting properties, but has the disadvantages of causing creep during neutral and poor transmission efficiency during normal traveling.

On the other hand, if a friction clutch such as a wet clutch is used as the starting clutch and the desired ideal starting characteristics are obtained by hydraulically controlling the friction clutch, the above drawbacks can be solved all at once, which is preferable. However, in the case of a friction clutch, it is difficult to realize a smooth startability like an automatic clutch, because the input speed changes greatly depending on whether the hydraulic pressure is on or off.

OBJECT OF THE INVENTION An object of the present invention is to provide a starting clutch control method capable of realizing smooth starting performance by using a friction clutch.

To achieve the above object, the control method of the present invention is a clutch control valve for controlling clutch hydraulic pressure to a starting clutch,
A solenoid valve that generates a signal hydraulic pressure for controlling the clutch control valve, and an electronic circuit that electronically controls the solenoid valve are provided, and the control circuit is for the target input rotation speed of the starting clutch according to the throttle opening. When the upper and lower limit values with the specified control width are set up and down and the actual input speed is outside the upper and lower limit values, the solenoid valve is continuously turned on or so that the actual input speed falls within the upper and lower limit values. When the valve is turned off and the actual input speed is within the upper and lower limits, duty control is performed so that the operating time of the solenoid valve changes according to the magnitude of the actual input speed.

That is, if the solenoid valve is controlled to be turned on and off so that the input speed of the starting clutch matches a certain target value, a difference between the target input speed and the actual input speed may occur due to a clutch hydraulic pressure delay. It cannot be resolved, hunting occurs, and you cannot start smoothly. On the other hand, when the duty of the solenoid valve is controlled, the convergence to the target value is delayed. On the other hand, in the present invention, ON / OFF control is performed so that the input rotation speed of the starting clutch falls within a predetermined upper / lower limit value including the target input rotation speed, and the input rotation speed is moderate within the upper / lower limit values. Since duty control is performed so as to change, hunting can be prevented and convergence to the upper and lower limit values is fast,
You can perform a smooth start without shock.

Description of Embodiments FIG. 1 shows an example of a starting clutch control device for carrying out the present invention. Reference numeral 1 denotes a starting clutch composed of a wet multi-plate clutch, and a piston 2 is moved to the left by a hydraulic pressure in a piston chamber 7. It moves so that the clutch plates 3 and 4 are brought into pressure contact with each other to interrupt the power. Reference numeral 5 is an input shaft directly connected to the engine, and 6 is an output shaft connected to the transmission.

The clutch control valve 10 has a spool 12 that is slidable in the valve body 11, and a spring 13 that constantly biases the spool 12 to the left, and an oil pressure source (not shown) is provided via an oil passage 30. The port 14 to which the line pressure is guided is opened and closed by the land 15 on the left side of the spool 12. The oil passage 31 branched from the oil passage 30 has a small diameter right end chamber in which the spring 13 is housed.
It is connected to 16 and a solenoid valve is provided in the middle of the branch oil passage 31.
An opening 32 that is opened and closed by a needle 41 of 40 is provided. For example, when the solenoid valve 40 is turned on, the needle 41 closes the opening 32, and the solenoid pressure acting on the right end chamber 16 rises.

The port 18 adjacent to the right side of the port 14 is connected to the piston chamber 7 of the starting clutch 1 via the oil passage 33, and the port 18 is connected to the valve body 11 via the communication hole 19 formed inside the spool 12. It communicates with the left end chamber 20. Therefore, the hydraulic pressure (clutch hydraulic pressure) of the piston chamber 7 of the starting clutch 1 is guided to the left end chamber 20 via the oil passage 33 and the communication hole 19 and presses the spool 12 to the right. Instead of the communication hole 19, another oil passage 33 may be provided in the valve body 11 to connect the oil passage 33 and the left end chamber 20 as shown by a broken line in FIG.

A drain port (oil drainage port) 21 is formed on the valve body 11 adjacent to the right side of the port 17, and the drain port 21 is opened and closed by a land 22 at the center of the spool 12.

The outside diameter a of the land 15 on the left side of the spool 12 is larger than the outside diameter b of the land 17 on the right side, the clutch hydraulic pressure acting on the land 15 is P _C , the solenoid pressure acting on the land 17 is P _S , and the spring of the spring 14 is. If the force is F, The clutch hydraulic pressure P _C is controlled so that the relationship of 1 is established.

The control circuit 50 is input with signals indicating running conditions such as the input speed N _i , the output speed N ₀ , and the throttle opening.
The duty of the solenoid valve 40 is controlled based on these signals. Here, the duty control is a constant cycle T ₀ including the ON time T ₁ and the OFF time T ₂ as shown in FIG.
The pulse signal of is input to the solenoid valve 40, and by changing the ratio (duty ratio D%) of the ON time T _{1 to} the cycle T ₀ of this signal, the solenoid pressure P proportional to the duty ratio D is applied to the solenoid valve 40. Control that causes _S.

For the above-mentioned control circuit 50, to obtain an ideal generator characteristic without shock, the relationship between the throttle opening and the target input rotational speed N _E as shown in FIG. 3 as an example, and the target input revolution speed N _E The upper and lower rotation speed widths (hereinafter referred to as the set value ΔN _E ) are stored in the data map. The upper limit value (N _E + ΔN _E ) and the lower limit value (N _E −ΔN _E ) shown by the broken line in FIG. 3 are reference values for determining the duty ratio D of the solenoid valve 40.
If the actual input speed N _i is equal to or higher than the upper limit value, the solenoid valve 40 is continuously turned on (D = 100%) and the starting clutch 1
When the input rotation speed N _i is equal to or lower than the lower limit value, the solenoid valve 40 is continuously turned off (D = 0%) to urge the starting clutch 1 in the disengagement direction. Further, when the input speed N _i is between the upper limit value and the lower limit value, the duty ratio D of the solenoid valve 40 is changed according to the magnitude of the difference between the input speed N _i and the target input speed N _E. The coupling force of the starting clutch 1 is finely controlled.

This can be summarized as follows.

When N _i > N _E + ΔN _E , D = 100% N _E + ΔN _E ≧ N _i ≧ N _E −ΔN _E , When N _i <N _E −ΔN _E , D = 0% The above equation is shown in FIG. 4. When the input speed N _i is between the upper limit value and the lower limit value, the input speed N _i The duty ratio D is in a proportional relationship. The present invention is not limited to such a relationship, and may be set so that the duty ratio D changes in a quadratic function with respect to the input rotation speed N _i as shown by the broken line in FIG. 4, for example. .

Here, an example of control of the present invention by the control circuit 50 will be described with reference to FIG.

First, when the control starts, input of the input speed N _i (6
0), input of the output speed N ₀ (61), and input of the throttle opening (62) are performed in sequence, and the third opening is performed according to the throttle opening.
Read the target input speed N _E and the set value ΔN _E from the figure (6
3). Next, the input speed N _i is compared with the initial speed N _C stored in advance in the control circuit 50 (64). This initial rotational speed N _C is the minimum rotational speed at which the starting clutch 1 should be disengaged,
It is set to about 800 rpm, which is slightly lower than the idle speed. When N _i <N _C, the engine will stop if the starting clutch 1 is connected as it is, so the solenoid valve 40 is turned off (D = 0%) and the starting clutch 1 is shut off (65). On the other hand, when N _i ≧ N _C , the difference between the input speed N _i and the output speed N ₀ is subsequently compared with the predetermined value ε (66). This value ε is a reference for determining whether the starting clutch 1 is in the engaged state or the semi-engaged state, and is set to, for example, about 200 rpm.

If | N _i −N ₀ | ≦ ε, it means that the start is completed, so the solenoid valve 40 is turned off (D = 100%) and the start clutch 1 is engaged (67). In the case of | N _i −N ₀ |> ε, it means that the starting clutch 1 is in the semi-engaged state, that is, in the middle of starting, and therefore the following starting control (68) is performed.

In the start control (68), first, the input speed N _i is compared with the upper limit value (N _E + ΔN _E ) (69), and if N _i > N _E + ΔN _E , the purpose is to connect the start clutch 1. The solenoid valve 40 is turned on because it means that it is insufficient compared with the starting characteristics.
To (67). As a result, the clutch hydraulic pressure P _C rises and the starting clutch 1 is biased in the connecting direction, so that the input speed
N _i decreases. When N _i ≤ N _E + ΔN _E , the input speed N _i is further compared with the lower limit value (N _{E −} ΔN _E ) (70), and N _i <N _E
-ΔN _E means that the connection of the starting clutch 1 is excessive, so the solenoid valve 40 is turned off (65). As a result, the clutch hydraulic pressure P _C decreases and the starting clutch 1 is biased in the disengagement direction, so that the input rotation speed N _i increases.

In the case of N _E + ΔN _E ≧ N _i ≧ N _E −ΔN _E , the duty ratio D corresponding to the input rotation speed N _i is calculated or read from the equation (1) or FIG. 4 (71), and this duty ratio D The signal is output to the solenoid valve 40 (72). As a result, the input rotation speed N _i is finely controlled in the direction in which it converges to the target input rotation speed N _E.

As described above, in the start control (68), the input rotation speed N _i
Exceeds the upper and lower limit values, the solenoid valve 40 is continuously turned on or off to continuously energize the starting clutch 1 in the connecting direction or the disengaging direction, and the input rotational speed N _i is swiftly set within the upper and lower limit values. To converge. When the input rotation speed N _i is within the upper and lower limit values, the solenoid valve 40 is duty-controlled according to the magnitude of the input rotation speed N _i , and the coupling force of the starting clutch 1 is finely controlled to input the rotation speed N _{i. i} is brought close to the target input speed N _E. Therefore, the desired starting characteristics can be quickly matched, and smooth starting performance can be realized.

In the above embodiment, the wet clutch is used as the starting clutch 1. However, a dry clutch may be used, and any clutch can be used as long as the coupling force of the clutch can be controlled by hydraulic pressure. .

EFFECTS OF THE INVENTION As is clear from the above description, according to the present invention, the upper and lower limit values are set with respect to the target input rotation speed, and when the actual input rotation speed exceeds the upper and lower limit values, they fall within the upper and lower limit values. As described above, the solenoid valve is continuously turned on or off, and when the value is within the upper and lower limits, the solenoid valve is duty controlled.
The input rotation speed can be quickly converged within the range of the upper and lower limit values of the target input rotation speed, and an ideal startability without shock can be easily obtained.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an example of a starting clutch control device according to the present invention, FIG. 2 is a signal waveform diagram of an example of duty control, and FIG. 3 is a diagram showing a relationship between a throttle opening and a target input rotation speed, FIG. 4 is a diagram showing the relationship between the input rotation speed and the duty ratio, and FIG. 5 is a flowchart diagram showing the operation of the control circuit. 1 ... Starting clutch, 10 ... Clutch control valve, 40 ... Solenoid valve, 50 ... Control circuit.

Claims (1)

[Claims] 1. A clutch control valve for controlling a clutch hydraulic pressure to a starting clutch, a solenoid valve for generating a signal hydraulic pressure for controlling the clutch control valve, and an electronic circuit for electronically controlling the solenoid valve. The circuit sets the upper and lower limit values that have a predetermined control range up and down with respect to the target input rotation speed of the starting clutch depending on the throttle opening, and when the actual input rotation speed is outside the upper and lower limit values, the actual input When the solenoid valve is continuously turned on or off so that the rotation speed is within the upper and lower limits, and the actual input speed is within the upper and lower limits, the solenoid valve A control method for a starting clutch, which is characterized by performing duty control in which an operation time changes.