JPH0419244Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention relates to a clutch switching device that connects and disconnects the power transmission system of a vehicle, and in particular, a clutch switching device that can switch the clutch by an actuator operated based on an arbitrary control program. It relates to a switching device.

(Prior Art) When clutch switching control is performed based on an arbitrary control program, conventionally, as shown in FIG.
This is done by controlling a normally closed solenoid valve 1 and a normally open solenoid valve 2 whose duty is controllable by a control means (not shown). The normally closed solenoid valve 1 allows communication between a fluid pressure actuator such as an air cylinder 3 and a high pressure air source 4 to be cut off. The normally open solenoid valve 2 always opens the air cylinder 3 to the atmosphere, closes the air cylinder 3 when it is on, and operates to open and close in response to a pulse signal with an arbitrary time ratio, so that the air pressure in the air cylinder 3 can be controlled in an arbitrary pattern over time. , thereby displacing the clutch from the disengagement direction to the engagement direction.

For example, when starting a vehicle, the clutch stroke (corresponding to the engaged and disengaged state of the clutch) is changed over time as shown in Fig. 2, and as shown in Fig. 3, each rotation of the engine and clutch output shaft is Start control is performed by controlling the numbers N and N1. In the pressure holding operations from time a to b and from time d to e, as shown in FIG. 5, the normally open solenoid valve 2 is controlled to be continuously energized and held in the closed position. Furthermore, from time point b to time point c, the normally open solenoid valve is turned off, the pressure is reduced all at once, and the clutch is moved in the tangential direction to the position P2 in FIG. In the pressure reduction operation from time c to time d, the normally open solenoid valve 2 is
The duty of the clutch is controlled so that the displacement of the clutch in the engagement direction over time becomes an arbitrary pattern.

(Problems to be solved by the invention) By the way, since the conventional normally open solenoid valve 2 shown in FIG. 7 performs both continuous closing control and duty control by continuous energization, the response during duty control is It is necessary to have both continuous current conductivity during continuous closing control. However, conventionally, when the normally open solenoid valve 2 increases the amount of current to improve responsiveness, heat generation during continuous energization becomes a problem, resulting in poor continuous energization.On the contrary, when continuous energization is improved (low heat When a small current is applied), there is a problem in that the responsiveness deteriorates, and the conventional normally open solenoid valve 2 could only maintain performance at a compromise. Furthermore, if such a normally open solenoid valve fails in a closed state where exhaust is not possible, the clutch cannot be engaged, which has been a problem. An object of the present invention is to provide a clutch switching device equipped with a plurality of electromagnetic valves that can improve clutch switching control characteristics.

(Means for Solving the Problems) In order to achieve the above object, the present invention provides a fluid pressure actuator that connects and disconnects a clutch between a vehicle engine and a transmission, and a fluid pressure chamber of the fluid pressure actuator. a normally closed first solenoid valve that is interposed in a passage communicating with a high-pressure fluid source and is continuously operated to open;
A normally closed second solenoid valve is installed in the discharge passage for discharging the fluid pressure supplied to the fluid pressure chamber and whose duty is controlled by a pulse signal during operation; and a normally closed second solenoid valve is installed in the discharge passage in parallel with the second solenoid valve. The normally open solenoid valve is continuously operated to close, and the normally closed first solenoid valve and the normally open solenoid valve are continuously operated to displace the clutch in the cross direction, and the normally open solenoid valve is continuously operated. The invention is characterized in that it further comprises clutch control means for duty-operating the normally closed second solenoid valve to displace the clutch in the tangential direction.

(Function) When the clutch control means displaces the clutch in the distal direction, it continuously operates the normally closed first solenoid valve and the normally open solenoid valve, and when it displaces the clutch in the concentric direction, it continuously operates the normally open solenoid valve. At the same time, the normally closed second solenoid valve is operated on a duty basis, and the continuous energization of the normally closed first and second solenoid valves can be significantly reduced.
Moreover, when the clutch is held, only the normally open solenoid valve is turned on.

(Embodiment) FIG. 1 shows a clutch switching device as an embodiment of the present invention. This clutch switching device controls switching of a clutch 10 between an engine and a transmission in a power transmission system mounted on a vehicle (not shown).
This clutch switching device includes an air cylinder 11 as a fluid pressure actuator that switches the clutch 10 via a link (not shown), an air supply/discharge pipe system 13 connected to an air chamber 12 which is a fluid pressure chamber of the air cylinder 11, and the clutch. The clutch controller 14 is comprised of a microcomputer that controls the switching of the clutch 10 in an arbitrary manner over time.

The air supply/drainage pipe system 13 is a pipe 1 that supplies high pressure air from an air tank 15, which is a high pressure air source, to the air chamber 12.
6, a normally closed first solenoid valve (hereinafter simply referred to as the first normally closed valve) 17, which connects and disconnects the pipe 16 midway, and the air chamber 12 and the atmosphere opening 18, which are intermittently opened and closed at an arbitrary time ratio. a normally closed second solenoid valve (hereinafter simply referred to as a second normally closed valve) 19 whose duty can be controlled; and an air pipe 22 which can shut off the air chamber 12 and the atmosphere opening 20
It is formed by a normally open solenoid valve (hereinafter simply referred to as a normally open valve) 21 that opens via the normally open solenoid valve. In particular, a second normally closed valve 19 and a normally open valve 21 are connected in parallel to an air pipe 22 forming an exhaust passage for exhausting air from the air chamber 12.
The first normally closed valve 17 is a duty control valve similar to the second normally closed valve 19, and when the clutch is returned to the disengaged direction by a predetermined amount, it can be opened and closed by a pulse signal with a predetermined duty ratio. The clutch is opened only while receiving continuous drive signals from the clutch controller 14 (duration is relatively short). The normally open valve 21 has good continuous current conductivity and closes only while receiving a drive signal from the clutch controller 14. The second normally closed valve 19 has good responsiveness in duty operation, and opens intermittently only while receiving a pulse signal of an arbitrary time ratio from the clutch controller 14.

The clutch controller 14 includes a clutch stroke sensor 23, a load sensor 24 that outputs an accelerator opening signal, an engine rotation speed sensor 25, a clutch rotation speed sensor 26 that outputs a clutch output shaft rotation speed signal, and a gear shift switch that outputs a gear shift signal. 27 and a gear position sensor 28 that outputs a gear position signal of the transmission, and the first
The normally closed valve 17, the second normally closed valve 19, and the normally open valve 21 are also connected.

A data table for determining the duty ratio α corresponding to the accelerator opening signal as shown in FIG. 6 is stored in the memory (not shown) of the clutch controller. A control program for obtaining temporal displacement characteristics in the bonding direction from the disconnected state is also stored and processed.

When such a clutch switching device operates when the vehicle starts, first, the clutch controller 14
checks the input signals of each sensor, turns off the output to the three solenoid valves 17, 19, and 21, maintains the clutch 10 in the engaged state, initializes it, and starts the start control. As shown in FIGS. 2 to 4, when time point a is reached, first the first normally closed valve 17
outputs a drive signal for a relatively short time t1,
At the same time, a drive signal is continuously outputted to continuously close the normally open valve 21 from time point a, and start control is entered. In this way, only the normally open valve 21 is kept on during the time point b after the elapse of the time t1 following the time point a. The clutch is in a completely disengaged state until time b, and at this point, when the controller 14 receives the driver's intention to start moving (for example, from the value of the load sensor 24), it opens the second normally closed valve 18, thereby increasing the clutch stroke. It is lowered to a predetermined value P2. From here, the second normally closed valve 18 opens and closes in response to a pulse signal with a smaller duty ratio α, causing the clutch air pressure to decrease slightly over time and entering a half-clutch state. In addition, if the engagement displacement of the clutch is too quick, the first normally closed valve 17 is duty-controlled to open and close for a predetermined time t2 (indicated by a two-dot chain line in FIG. 4). During this period, the engine speed N gradually increases, and at time d, a portion of the engine rotational force begins to be transmitted to the clutch output shaft side.
At this time point d, the output of the pulse signal to the second normally closed valve 19 is cut off, only the normally open valve 21 is kept on, and the clutch stroke pressure is held at a constant value P3. After time d, the rotational speeds N and N1 of the engine and the clutch output shaft become close to each other, and at time e, both rotations match, and at that time, the output of the continuous drive signal to the normally open valve 21 is also cut off, and the air chamber is closed. 12 is completely exposed to the atmosphere and the start process is completed.

In the above, the air cylinder 11 was explained as a fluid pressure actuator, but instead of this, a hydraulic cylinder is used, high pressure oil is supplied from a hydraulic source, and three electromagnetic valves similar to those explained in FIG. The used clutch may be displaced over time in any manner toward the joining direction.

(Effects of the invention) As described above, the clutch switching device according to the invention can be used in combination with the duty valve, which is the second normally closed valve with good responsiveness during duty control, and the normally open valve with good continuous energization. The overall durability is improved by using the first normally closed valve, the second normally closed valve, and the normally open valve, and in particular, the responsiveness of the second normally closed valve and the continuous conductivity of the normally open valve are sufficiently ensured. This improves the responsiveness and reliability of clutch switching control.

[Brief explanation of the drawing]

Fig. 1 is a schematic configuration diagram of a clutch switching device as an embodiment of the present invention, Fig. 2 is a graph of changes over time in the clutch stroke controlled by the above device, and Fig. 3 is a diagram showing the engine and Figure 4 is a diagram of the change in rotation speed of the clutch output shaft over time, Figure 4 is a diagram of the operating characteristics of the solenoid valve in the same device, Figure 5 is a diagram of the operating characteristics of the solenoid valve used in the conventional clutch switching device, and Figure 6 is the diagram of the operating characteristics of the solenoid valve used in the conventional clutch switching device. FIG. 1 shows a data table for determining the duty ratio stored in the clutch controller, and FIG. 7 shows a block diagram of the main parts of a conventional clutch switching device. 10...Clutch, 11...Air cylinder, 1
2...Air chamber, 14...Clutch controller,
15... Air tank, 17... First normally closed valve, 19
...Second normally closed valve, 21...Normally open valve, 18, 20...
...Atmospheric opening.

Claims (1)

[Scope of utility model registration request] A fluid pressure actuator that connects and disconnects a clutch between the engine and transmission of a vehicle, and a normally closed valve that is continuously operated to open and is interposed in a passage that communicates a fluid pressure chamber of the fluid pressure actuator with a high pressure fluid source. a normally-closed second solenoid valve that is interposed in a discharge passage for discharging fluid pressure supplied to the fluid pressure chamber and whose duty is controlled by a pulse signal during operation; and a second solenoid valve that is disposed in the discharge passage. A normally open solenoid valve is inserted in parallel with the normally open solenoid valve and the normally open solenoid valve is continuously operated to displace the clutch in the cross direction by continuously operating the normally closed first solenoid valve and the normally open solenoid valve to displace the clutch in the cross direction. A clutch switching device comprising clutch control means for continuously operating a solenoid valve and duty-operating the normally closed second solenoid valve to displace the clutch in the tangential direction.