JPH02266117A - Controller for hydraulic clutch - Google Patents

Abstract

PURPOSE:To make a shock hard to occur even if discharge pressure of a hydraulic pump gets out of a condition by adjusting a set time of initial open operation to be shorter at time of on-operation to be done after this operation in the state that time of up to torque surge occurrence is shorter than the specified value. CONSTITUTION:A controller 25 has a control means A directly controlling each of valves V1, V2, and a time adjusting means B loading a parameter to determine a set time for initial open operation to the former. When an operating signal is outputted, if a torque surge occurs within the preset time, operation takes place on the basis of time of up to the occurrence timing, and it changes a parameter so as to shorten the set time. Accordingly, when clutches C1, C2 are subjected to on-operation, the set time is shortened, therefore the surge corrence timing is settled within the ideal time range, and that a peak value is set to a lower one.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention provides a method for controlling the valve mechanism in a preset manner when operating the valve mechanism to the input side for operating the hydraulic clutch installed in the travel transmission system. A hydraulic clutch comprising a control means that performs an initial opening operation to open the valve mechanism for a set time at an opening degree, and after this initial opening operation, opens the valve mechanism from an opening degree lower than the opening degree according to predetermined characteristics. More specifically, the present invention relates to an improvement for reducing shock when a hydraulic clutch is engaged.

[Conventional technology]

Conventionally, a method for adjusting the opening degree of a valve mechanism when engaging a hydraulic clutch as described above is disclosed in Japanese Patent Application Laid-open No. 63-3.
There is a control system disclosed in Japanese Patent No. 08225, and as explained in this reference, in this type of control system, at the start of the engagement operation of the hydraulic clutch, the piston of the hydraulic clutch is moved between the friction plates of the hydraulic clutch. By operating the clutch until it touches the clutch, the time required for the engagement operation is shortened, and after this operation, the pressure on the piston is increased from a relatively low value to maintain the half-clutch state for an appropriate amount of time. It is constructed so that the hydraulic clutch engagement operation can be completed without generating much shock.

[Problem to be solved by the invention]

Now, considering the control operation in the above cited example, in this cited example, when the hydraulic clutch is engaged, the valve mechanism is opened wide for a set time, and then the valve mechanism is adjusted to a predetermined characteristic from a small opening degree. It is configured to be operated along the opening line.

However, with a valve mechanism like this that opens the valve mechanism widely for a set time, for example, when the engine speed is set high or the discharge pressure of the hydraulic pump is high, the unit of pressure oil for the hydraulic clutch is Since the supply amount per unit of time increases, the clutch may reach an engaged state within the set time period in which the valve mechanism is largely opened at the beginning of control, causing a shock.

In other words, in the cited example, the set time for opening the valve mechanism is predetermined at the beginning of the control.
In this way, a shock may occur if the discharge pressure of the hydraulic pump or the like deviates from the conditions assumed when determining the set time.

Another cause of such shock is a decrease in the viscosity of the hydraulic oil due to an increase in the oil temperature.

An object of the present invention is to construct a control device which, through rational improvements, does not cause a shock as much as possible even if the discharge pressure of a hydraulic pump deviates from the conditions assumed for the hydraulic clutch.

[Failure to solve the problem]

As described above, the present invention is characterized in that in a control device that performs an initial opening operation of a hydraulic clutch, a sensor for detecting torque is provided in the travel transmission system, and the torque is detected by the sensor based on the timing at which the initial opening operation is started. The time until the torque surge occurs is determined, and if the time value thus determined is smaller than a predetermined value, the set time of the initial opening operation is set to a smaller value in the engagement operation performed after this engagement operation. The present invention has a time adjustment means for adjusting the value, and its functions and effects are as follows.

[For production]

If the above characteristics are configured as shown in Fig. 1, for example, as shown in Fig. 3 (A), the hydraulic clutch (C) is engaged and operated by setting the set time for initial opening to (To). At this time, the surge pressure (P) is measured by the sensor (
S), when the hydraulic clutch (C) is subsequently engaged, the setting time of the initial opening operation is set to (T,), which is a smaller value than (T,), as shown in Figure 4 (A).
2).

In other words, in the present invention, the time range (Tx) shown in FIG.
Ideally, the torque surge should be detected within the time range (Tx ) The phenomenon in which a torque surge is detected before reaching ) means that there is an oversupply of pressure oil, so by shortening the decision time for the initial opening operation as described above, the timing of the occurrence of the torque surge can be set to the ideal timing. It can be set to a value.

In addition, when detecting a torque surge within the ideal time range (Tx), the opening degree of the valve mechanism (v) is low, so the peak value of the torque surge is low and the shock is small. When increasing the opening degree, a half-clutch state can be obtained from an early stage, so that the clutch engagement operation can be completed smoothly.

〔Effect of the invention〕

Therefore, by providing a sensor that detects torque and providing a time adjustment means that adjusts the setting time of the initial opening operation based on the detection result from this sensor, the discharge pressure of the hydraulic pump can be increased, etc. Even if the clutch becomes disengaged, a control device has been constructed that can engage and operate the clutch without generating too much shock.

〔Example〕

Embodiments of the present invention will be described below based on the drawings.

As shown in Figure 2, a running latch (2) to which power from the engine (1) is transmitted, and an external clutch (3)
The power from the running latch (2) is transmitted to the cylindrical input shaft (4) for the running system, and the power from the external clutch (3) drives the external power shaft (5). It is transmitted to the power transmission shaft (6) that fits inside the human power shaft (4) of the reservoir.

As shown in the figure, a clutch case (8) is externally fitted and fixed to the input shaft (4) via a key (7), and an output gear (9) is externally fitted in a reversed state, and Input shaft (4)
An input gear (11) is externally fitted and fixed to a cylindrical intermediate shaft (10) disposed coaxially with the cylindrical intermediate shaft (10).

Moreover, an idle gear (12) and two gears (13) and (14) are connected between the output gear (9) and the input gear (11).
) is formed, and the clutch case (8) transfers the power from the input shaft (4) to the output gear (
9) and the input shaft (4).
) and a second hydraulic clutch (C2) that directly transmits the power from the input gear (11) to the input gear (11).
(16)...and hydraulic pistons (17), (18)
), each hydraulic clutch (CI), (
Both C2) can be set to a transmission state by supplying pressure oil.

Incidentally, the power from the intermediate shaft (10) is transmitted to the transmission device (1
9), and the wheel (20) via the torque sensor (S)
A transmission system is formed so that the power is transmitted to the

Further, this transmission system is configured to be installed in an agricultural tractor, and in this transmission system for traveling, the first and second hydraulic clutches (CI), ((2)) are configured to generate as little shock as possible when changing gears by operation. A system is provided for controlling the pressure of hydraulic fluid to the first and second hydraulic clutches (CI) and (C2).

In other words, as shown in Fig. 1, pressure oil from the hydraulic pump (21) is sent to the forward/reverse switching valve (22);
2) to the first and second hydraulic clutches (CI) (C2), respectively, and the oil passages (23) and (24) are equipped with electromagnetic proportional pressure reducing valves (Vl) and (Vz) (an example of a valve mechanism). ) are interposed, and these two electromagnetic proportional pressure reducing valves (vl) (ν
2) is controlled by an operation signal from a control device (25) that includes a microprocessor (not shown), and the control device (25) includes a changeover switch (2) that detects the operating position of the valve (22). 26) and a control system to which signals from the torque sensor (S) are input.

Further, each of the electromagnetic proportional pressure reducing valves (Vl) and (V2) is configured to adjust its opening degree in proportion to the current value of the operation signal output from the control device (25), and the control device (25) When both clutches (CI) and (C2) are engaged, they are opened at a preset large opening for a set time (TO) as shown in Figure 3 (a), and After this initial opening operation, the valve (Vl), (V2) (7) opening degree is changed from an opening degree lower than this large opening degree.
Said 1. The operation is programmed to feed back the signal from the engine to obtain and increase the predetermined torque, and furthermore, this control system can reduce the shock by adjusting the set time. , its behavior is set.

In other words, as shown in FIG. 1, the control device (25) includes a control means (A) that directly controls the valves (Vl) and (V2), and a control means (8) that controls the initial opening operation. and a time adjustment means (B) for loading parameters for determining the set time, and when the operation signal is output as shown in FIG. The torque surge (P) is maintained for a predetermined setting time (
When the torque surge (P) occurs at time (TI) within TO), calculations are performed based on the time until the occurrence timing of the torque surge (P), and the parameters are changed so as to shorten the set time.

Therefore, when the parameters are changed in this way, the next time the clutch (CIL (C2)) is engaged and operated, the setting time will be shortened to (T2) as shown in Figure 4 (a). , As a result, the timing of occurrence of torque surge (P) is within the ideal time range (Tx
), and the peak is also low.

Note that FIG. 3 (D) and FIG. 4 ([+) are graphs showing the clutch internal pressure when the set time is set to (To) and (T2), respectively.

Furthermore, as shown in Fig. 5, this control system adjusts the set time of the initial opening operation even when a torque surge (P) is detected at a timing delayed from the ideal time range (Tx) described above. In this case, the set time is increased the next time the clutches (C+) and (cz) are engaged, and as a result, the torque surge (P) is increased as described above.
The timing of occurrence of Tx falls within an ideal time range (Tx).

The above operation is called a learning function, and each time clutches (C+) and (C) are engaged and operated, the timing of occurrence of torque surge (P) is sampled and the set time is adjusted. This ensures that the shock is constantly reduced.

[Another example]

In addition to the embodiments described above, the present invention may also include, for example, a hydraulic clutch used for speed change, and the control means and time adjustment means can each be configured by either hardware or software. .

Incidentally, although reference numerals are written in the claims section for convenient comparison with the drawings, the present invention is not limited to the structure shown in the accompanying drawings.

[Brief explanation of drawings]

The drawings show an embodiment of a control device for a hydraulic clutch according to the present invention, in which FIG. 1 is a block circuit diagram of the control device, FIG. 2 is a schematic diagram of a transmission system, and FIG. 3 shows a valve in a preset state. Fig. 4 is a timing chart showing the current value, clutch pressure, and torque when the initial opening time of the valve is shortened, and Fig. 5 is a timing chart showing the current value, clutch pressure, and torque when controlling the valve. 2 is a timing chart showing the current value, clutch pressure, and torque when the initial opening time of the clutch is increased. (8)...Control means, (B)...Time adjustment means, (C)...Hydraulic clutch, (s)
...sensor, (v) ...valve mechanism.

Claims (1)

[Claims] An initial stage in which the valve mechanism (V) is opened at a preset opening degree for a set time when the valve mechanism (V), which operates the hydraulic clutch (C) installed in the travel transmission system, is operated to the input side. A control device for a hydraulic clutch comprising a control means (A) that performs an opening operation and, after the initial opening operation, opens the valve mechanism (V) from an opening degree lower than the opening degree according to predetermined characteristics. A sensor (S) for detecting torque is provided in the travel transmission system, and the time until the occurrence of a torque surge detected by the sensor (S) is determined based on the timing at which the initial opening operation is started. In a state where the value of the time obtained in this way is smaller than a predetermined value, the time adjustment means (B
) A hydraulic clutch control device comprising: