JPH023764A - Working vehicle - Google Patents

Abstract

PURPOSE:To engage a hydraulic clutch rapidly without generating a shock, by a method wherein during engaging operation of a hydraulic clutch, after a control valve is opened to a given opening once, a feed oil amount is increased with given characteristics starting from an opening lower than the opening of the control valve. CONSTITUTION:When a hydraulic clutch is operated for engagement, a control valve 17 is opened to a given opening. After a feed oil amount to a hydraulic clutch is increased once, a feed oil amount is increased with given characteristics starting from an opening lower than the opening of the control valve, and the control valve 17 is opened to a full opening state being a value higher than a given opening. After the hydraulic clutch is operated to an extent that a friction plate in a clutch case makes contact therewith, the control valve 17 is gradually opened from a throttles state, where by the hydraulic clutch can be operated rapidly without generating a shock.

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention relates to a work vehicle, and more particularly, the present invention relates to a work vehicle, and more particularly, when the gear shift system completes a shift operation, a gear shift system is operated to transmit power from the gear shift system to the traveling system. Equipped with a hydraulic clutch,
The present invention relates to technology for smoothly controlling this hydraulic clutch.

[Conventional technology]

Conventionally, as a technique for smoothly controlling the hydraulic clutch as described above, there is a technique disclosed in Japanese Patent Application Laid-Open No. 62-231841, etc. In this reference, an acceleration sensor is provided on the traveling vehicle body, By adjusting the operating oil pressure for the hydraulic clutch based on the feedback signal from the acceleration sensor, smooth running is ensured without causing shock, regardless of the running conditions.

[Problem to be solved by the invention]

Furthermore, in the configuration of this reference, when changing gears, the supply of hydraulic oil to the hydraulic clutch is cut off, and at the same time, the oil is drained from the hydraulic clutch, and after setting the hydraulic clutch to the disengaged state, the gear shifting operation of the gear shifting system is performed. After this, an operation sequence is set so that hydraulic oil is supplied to the hydraulic clutch.

However, considering the case where a hydraulic clutch that has reached the disengaged state is engaged, this type of hydraulic clutch is designed to ensure that the power is cut off when the hydraulic clutch is disengaged.
Since it is equipped with a spring that applies a biasing force in the direction of separating the friction plates in the clutch case, even if a certain amount of hydraulic oil is supplied, the blockage will occur before the transmission state (engaged state) is reached. It takes a certain amount of time for the friction plates in the clutch case to start contacting each other and reach a press-contact state.

Therefore, even if the hydraulic clutch is configured to adjust the hydraulic oil pressure to the hydraulic clutch based on the feedback signal from the acceleration sensor as described above when the hydraulic clutch is engaged, in the initial stage of control, that is, the friction plate inside the clutch case In a state where the two are separated from each other, desired control cannot be performed, and there is room for improvement.

An object of the present invention is to set the hydraulic clutch to a transmission start state as quickly as possible when engaging and operating the hydraulic clutch that is disengaged during the gear shifting operation of a gear transmission system, and to generate as little shock as possible. The point is to configure the system to enter and operate the system.

[Means to solve the problem]

The features of the present invention include a gear transmission mechanism that changes the traveling speed;
It is equipped with a hydraulic clutch that is operated to disengage when the gear change operation of this gear transmission mechanism is performed, and a control valve that engages and operates the hydraulic clutch at the timing when the gear transmission mechanism is set to a transmission state, and when the hydraulic clutch is engaged and operated, After opening this control valve to a predetermined opening and once increasing the amount of oil supplied to the hydraulic clutch, the amount of oil supplied is increased using a predetermined characteristic starting from an opening that is lower than this opening. The control means is provided with a control means for opening the control valve to a fully open state with a value higher than the predetermined opening degree and setting the hydraulic clutch in a connected state, and its operation and effects are as follows. That's right.

[For production]

If the above characteristics are configured as shown in FIG. 1, for example, when the hydraulic clutch (C) is engaged, the configuration shown in FIG.
As shown, the control signal voltage for the control valve (17) is set to (
Em) and maintain this state as (Timel).
The control signal voltage for the control valve (17) is further lowered to ([En), and then the control valve ( 17), and finally, the control valve (17) is completely opened and the hydraulic clutch (17) is opened completely.
C) will be set to the connected state.

In other words, when operating the hydraulic clutch (C) in the disengaged state, the control valve (17) is temporarily opened wide,
After operating the hydraulic clutch (C) in advance to the extent that the friction plate (not shown) in the clutch case makes contact, the control valve (
17) gradually expands from the throttled state, it is possible to shorten the time required to set the hydraulic clutch (C) to the transmission state, and moreover, the initial operation of the control valve (17) in the opening direction can be performed in the fully open state. Therefore, by setting this release amount, it is possible to perform control starting from an appropriate half-clutch state without supplying an excessive amount of hydraulic oil.

〔Effect of the invention〕

Therefore, a system has been constructed in which the hydraulic clutch is quickly set to the transmission start state, and the hydraulic clutch is engaged without generating too much shock.

〔Example〕

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

FIG. 1 shows a transmission system of an agricultural tractor as an example of a working vehicle and a control system of a hydraulic clutch (C).

In other words, the transmission system consists of a system that transmits power from the engine (2) via the main clutch (1) to the traveling system, and a
The PTO system consists of a gear transmission mechanism (3) that changes gears in two stages, high and low, a transmission shaft (4), and a one-way clutch (5) installed on this transmission shaft (4). ), the PTO shaft (6), which takes out the power from the transmission shaft (4), (6
), and the traveling system includes a gear-type main transmission mechanism (9) that changes gears in four stages using two hydraulic actuators (7) and (8), and a transmission system from this main transmission mechanism (9). A hydraulic clutch (C) through which power is transmitted, and this hydraulic clutch (
A forward/reverse transmission mechanism (10) that manually switches the power from C) in the forward/reverse direction, and a gear type that uses a hydraulic actuator (11) to shift the power from this forward/reverse transmission mechanism (10) into two high and low gears. The sub-transmission mechanism (12) and the power from the sub-transmission mechanism (12) are transmitted to the output shaft (13) and the differential gear (12).
The power from the rear wheels (14) and the auxiliary transmission mechanism (12) is transmitted via the intermediate shaft (15) and the differential gear (14a).
16a) The hydraulic clutch (C) is disengaged immediately before the transmission operation of the traveling transmission system, and is operated after the transmission operation is completed. By being equipped with a control system (not shown) that operates the hydraulic clutch (C) in conjunction with the gear shifting operation so that the gear shifting operation is performed, the gear shifting operation can be performed easily without disengaging the main clutch (1). system is configured.

In addition, the hydraulic clutch (C) is equipped with an electromagnetic proportional pressure reduction type control valve (
A system for supplying pressure oil from the hydraulic pump (18) is formed through the control valve (17), and the control valve (17) is connected to the output shaft (17).
3) is operated in the entry direction by a signal from a control device (20) (an example of a control means) that operates based on a feedback signal from a torque sensor (19) provided in the control device (20).

In other words, as the voltage signal increases, the control valve (17)
The control device (20
) is operated by the control valve (1
7) The operation is as follows.

When the control to engage and operate the hydraulic clutch (C) is started, the control voltage (E
m), followed by the set time (Time2)
outputs the control voltage (Em) (#1.lt2 step.

This operation is to set the friction plates of the hydraulic clutch (C) to a sliding state in a short time, and immediately after this operation, the hydraulic clutch (C) is set to a substantially half-clutch state. The control voltage and control time are determined.

Next, input the signal from the torque sensor (19) after a while #3. #4 Stepper calculates the rate of increase in torque (Tx) in the travel transmission system from the difference between these signals (#5 Stepker).

In addition, the control reference value is set as shown in Figure 3 (b) so that the torque acting on the traveling transmission system increases at a predetermined rate.
In this figure, the control lower limit increase rate (TL) and the control upper limit increase rate (T, t) are determined based on the reference torque increase rate (TO).
is set, and the increase rate (T
The magnitude relationship between I) and (TL>, (TI) is determined (
#7.88 Stetska.

As a result of this determination, if TX<TL, the current control valve (
17) to the control voltage (Ex) output to the set voltage (
Bp) and set this value as the control voltage (Ox). Also, if TX>TI, set voltage from the control voltage (Ex) currently output to the control valve (17). (Bp) and convert this value into the control voltage ([Ex)
It should be set as #10, and also T, ≧TX≧T
In the case of t, the set voltage (Bp) is added to the control voltage (Bx) currently output to the control valve (17) to set the torque value in an upward trend and obtain the control voltage (Ex). , #9, #10 steps set control voltage (I
I! x), (Ex), set voltage (8p
) is added to obtain the control voltage (εX), and the control voltage (Ex) obtained by this process is output to the control valve (17) (
#11 Sticker.

Then, this control is performed until the set time (Time3) elapses (#12 sticker, this set time (Time3)
), the maximum control voltage is output to the control valve (17) to maintain the control valve (17) in an open state.

In addition, as shown in the graph of Figure 3 (b), the torque sensor (19)
When a signal is input from the control valve (17), the voltage signal output to the control valve (17) changes as shown in the graph of FIG. 3(A).

[Another example]

In addition to the above-mentioned embodiments, the present invention may also include, for example, the control means combined with elements such as logic gates and comparators.
Further, the control valve can be arbitrarily selected from a rotary type, a spool type, etc., and the present invention can also be applied to a combine harvester or a rice transplanter as a working vehicle.

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 the drawing]

The drawings show an embodiment of the working vehicle according to the present invention, FIG. 1 is a schematic diagram of the transmission system and control system, FIG. 2 is a flowchart showing the operation of the control device, and FIG. 3 (A) shows signals to the control valve. A graph representing the voltage, and FIG. 3 (b) is a graph representing the signal from the torque sensor. (9), (12)...Transmission mechanism, (17)...
...control valve, (20) ...control means,

Claims (1)

[Claims] Gear transmission mechanism (9), (12) that changes the traveling speed
, the hydraulic clutch (C) which is disengaged when the gear transmission mechanisms (9), (12), etc. are operated to change gears, and the timing at which the gear transmission mechanisms (9), (12), etc. are set to the transmission state. control valve (17) that engages and operates the hydraulic clutch (C) at
), and when the hydraulic clutch (C) is engaged, the control valve (17) is opened to a predetermined opening degree to temporarily increase the amount of oil supplied to the hydraulic clutch (C). , with a predetermined characteristic starting from an opening value lower than this opening degree, the amount of supplied oil is increased, and the control valve (17) is opened to a fully open state with a value higher than the predetermined opening degree,
Control means (2) for setting the hydraulic clutch (C) in a connected state
0).