JPH0659799B2 - Hydraulic clutch device for traveling of work vehicle - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a traveling hydraulic clutch device for a work vehicle, and in order to suppress a shock when operating a traveling hydraulic clutch of a friction type in an engaged state. Of technology.

[Prior Art] As a technique for suppressing a shock when the hydraulic clutch for traveling of a work vehicle is operated to an engaged state, for example, Japanese Patent Laid-Open No. 62-62160
-231841 has a structure disclosed.

With this structure, the pressure of the hydraulic oil supplied to the traveling hydraulic clutch is adjusted based on the acceleration of the machine body when the traveling hydraulic clutch is operated to the on state, and shock is suppressed. However, the operation of the running hydraulic clutch is not performed slowly.

[Problems to be Solved by the Invention]

When operating the friction-type hydraulic clutch for traveling as described above, a certain amount of hydraulic oil is required from the start of hydraulic oil supply until each friction plate starts contact and reaches the half-clutch state. Is. Then, after reaching the half-clutch state, while maintaining the half-clutch state for an appropriate time,
Generally, the internal pressure of the clutch is gradually increased to accelerate the aircraft.

On the other hand, in the above-described structure, the sensor for detecting the acceleration of the machine during traveling is provided, and the detection signal from the sensor is fed back to the traveling hydraulic clutch even when the speed is increased in the half-clutch state.

Therefore, in a state in which the front-rear posture of the machine body is likely to change, such as when traveling on an uneven terrain, when the half-clutch state of the traveling hydraulic clutch is applied, the change in the front-rear posture of the machine body causes a change in the acceleration of the machine body to the traveling hydraulic clutch. Since the feedback occurs, the internal pressure of the traveling hydraulic clutch changes and the hydraulic oil pulsates when a half-clutch is generated, causing a shock, or the traveling hydraulic clutch takes a long time to be engaged. There are cases.

It is an object of the present invention to configure the traveling hydraulic clutch so that the traveling hydraulic clutch can be quickly put into the engaged state while suppressing shock as much as possible when traveling on rough terrain.

[Means for Solving the Problems]

A feature of the present invention is to configure the hydraulic clutch device for traveling of a work vehicle as described above as follows.

After the clutch engagement command is issued, hydraulic oil of a predetermined pressure is supplied to the traveling hydraulic clutch, and when the acceleration of the aircraft increases in acceleration due to the supply of the hydraulic oil and reaches a predetermined value, the clutch engagement command is issued. There is provided control means for increasing the clutch internal pressure of the traveling hydraulic clutch at an increasing rate in accordance with a predetermined characteristic that is set on the basis of the time point at which the hydraulic pressure is output.

[Action]

(I) When configured as in the present invention, for example, as shown in FIG.
When a clutch engagement command for the traveling hydraulic clutch is issued,
Regardless of the acceleration of the airframe, the hydraulic oil (Ima
x, Ic) is supplied to the traveling hydraulic clutch.

As a result, the traveling hydraulic clutch quickly reaches the half-clutch state, the traveling speed of the machine body starts to increase, and the acceleration of the machine body also increases. In this case, the hydraulic oil (Imax, Ic, Ic, Ic
Is supplied to the traveling hydraulic clutch.

Then, when the acceleration in the accelerating direction of the machine body rises to a predetermined value, the clutch internal pressure of the traveling hydraulic clutch is increased according to a preset predetermined characteristic (If), and the traveling hydraulic clutch is in the on state. Reach In this case, the clutch internal pressure of the traveling hydraulic clutch will be in accordance with the preset characteristic (If) regardless of the state where the acceleration of the machine body increases while fluctuating due to changes in the front-back posture of the machine body, etc. Is operated to rise.

(Ii) As described above, even in a state where the acceleration of the machine body rises while fluctuating due to changes in the front-back posture of the machine body, regardless of this, hydraulic oil of a predetermined pressure and a predetermined characteristic set in advance Since hydraulic oil with a pressure along the line is supplied to the traveling hydraulic clutch, the clutch internal pressure of the traveling hydraulic clutch does not change and the hydraulic fluid does not pulsate when traveling on rough terrain. There is no occurrence.

(Iii) Since hydraulic oil having a predetermined pressure is supplied to the traveling hydraulic clutch until the acceleration in the acceleration direction of the machine body reaches a predetermined value, the traveling hydraulic clutch quickly reaches the half-clutch state. Therefore, it does not take a long time until the traveling hydraulic clutch reaches the engaged state.

(Iv) When switching from a state in which hydraulic oil of a predetermined pressure is being supplied to the traveling hydraulic clutch to a state in which the clutch internal pressure of the traveling hydraulic clutch is increased in accordance with a predetermined characteristic, the machine is increased. When the acceleration in the speed direction reaches a predetermined value, that is, when the acceleration of the machine body reaches a predetermined value while increasing from a value lower than the predetermined value, the switching operation described above is performed.

As described above, since the above-described switching operation is performed while the speed of the machine body is being increased, the shock caused by the switching operation is less likely to occur.

〔The invention's effect〕

As described above, even when traveling on rough terrain, it is possible to quickly operate the hydraulic clutch for traveling while suppressing the shock without being affected by changes in the front-back posture of the aircraft. We were able to improve the running performance of the car.

Then, even in the case of performing a switching operation from a state in which hydraulic oil of a predetermined pressure is being supplied to the traveling hydraulic clutch to a state in which the clutch internal pressure is increased according to a predetermined characteristic,
Since the switching operation is performed with less shock, the traveling performance of the work vehicle can be further improved.

〔Example〕

 Embodiments of the present invention will be described below with reference to the drawings.

As shown in FIG. 2, a traveling clutch (2) to which power from the engine (1) is transmitted and an external clutch (3) are provided, and the power from the traveling clutch (2) is a tubular shape for the traveling system. The power from the external clutch (3) is transmitted to the input shaft (4), and is transmitted to the transmission shaft (6) fitted inside the input shaft (4) for driving the external power shaft (5). The clutch case (8) is externally fitted and fixed to the input shaft (4) via the key (7), and the output gear (9) is externally fitted to the input shaft (4) so as to be coaxial with the input shaft (4). The input gear (11) is fixed to the cylindrical intermediate shaft (10) arranged.

Idle gear (12) between output gear (9) and input gear (11)
And a reverse gear transmission system composed of two gears (13) and (14) is formed, and the first hydraulic pressure for transmitting the power from the input shaft (4) to the output gear (9) in the clutch case (8). Contains the clutch (C ₁ ) (corresponding to the traveling hydraulic clutch) and the second hydraulic clutch (C ₂ ) (corresponding to the traveling hydraulic clutch) that transmits the power from the input shaft (4) directly to the input gear (11). Has been. The first and second hydraulic clutches (C ₁ ) and (C ₂ ) have a large number of friction plates (15) and (16).
And hydraulic pistons (17), (18), and is configured to be operated in an on state by supplying hydraulic oil.

Power from the intermediate shaft (10) is passed through the transmission (19) to the wheels (20).
And a transmission system for traveling is formed. This transmission system is configured to be installed in an agricultural tractor. In the transmission system of this transmission system, the first and second transmission systems are provided.
Hydraulic clutch (C _1), the operation so as not to generate as much as possible shock during shifting by the (C _2), first and second hydraulic clutch (C _1), control system for controlling the pressure of hydraulic fluid to (C ₂₎ Is provided.

Next, this control system will be described. As shown in FIG. 1, the hydraulic oil from the hydraulic pump (21) is sent to the forward / reverse switching valve (22), and the first / second hydraulic clutch (C ₁ ), Electromagnetic proportional pressure reducing valves (V ₁ ) and (V ₂ ) are provided in the oil passages (23) and (24) for sending the hydraulic oil to (C ₂ ), respectively. The electromagnetic proportional pressure reducing valves (V ₁ ) and (V ₂ ) are operated by an operation signal from a control device (25) that incorporates a microprocessor (not shown), and the control device (25) operates the forward / reverse switching valve (22 Signal from the changeover switch (26) for detecting the operating position of (1) and the sensor (S) for detecting the number of rotations of the wheel (20). Control device (25) is set the program to operate according to the flowchart of FIG. 3, this program first or second hydraulic clutch (C _1), the operation to the state to enter the (C ₂₎ Along with this, a control means (T) for increasing the clutch internal pressure at a predetermined increase rate is formed.

Next, based on the flowchart of FIG. 3, the control device (25)
The operation of will be described.

Based on the signal from the selector switch (26), the forward / reverse selector valve (2
When it is detected that 2) has been operated (steps # 1 and # 2) (corresponding to the clutch engagement command), a signal (If) (corresponding to the predetermined characteristic) having the characteristic shown by the broken line in FIG. 4 is sent. generator for generating (program software to is constituted by) actuates the (# 3 step), the solenoid proportional pressure reducing valve of the supply side of the hydraulic oil (V _1), the (V _2), a relatively high current value ( Im
The operation signal of ax) is supplied only for the time (T ₁ ) (# 4 step). Then, the operation signal is lowered to a current value (Ic) lower than the current value (Imax) (# 6 step).

The electromagnetic proportional pressure reducing valves (V ₁ ) and (V ₂ ) are configured to increase / decrease the pressure of the hydraulic oil in response to the increase / decrease in the supplied current value. As described above, the operation signal (current value (Imax))
The reason for increasing only (T ₁ ) is that the first and second hydraulic clutches (C ₁ ), (C ₂ ) have the friction plates (15), (16) narrowed in advance, and This is to shorten the operation time of the second hydraulic clutches (C ₁ ) and (C ₂ ) to the engaged state.

Next, the acceleration (X) in the acceleration direction of the aircraft is detected based on the signal from the sensor (S) (step # 8), and the detected acceleration (X) and a predetermined value (α) set in advance. And (# 9 step). As a result of this comparison, when the acceleration (X) substantially coincides with the predetermined value (α), the operation signal is increased to the current value (Imax) along the signal (If) from the generator, and the first or second Operate the hydraulic clutches (C ₁ ) and (C ₂ ) in the engaged state (steps # 10 and # 11).

In this case, the timer (configured as a software program) is started at the same time (# 5 step), and the timer determines whether the time (T ₂ ) has elapsed (# step), Even if the acceleration (X) in the acceleration direction of the aircraft has not reached the predetermined value (α), if the time (T ₂ ) elapses, the operation signal is changed to the current value along the signal (If) from the generator as described above. It is configured to operate up to (Imax). As a result, the first or second hydraulic clutch (C ₁ ),
The operation time of (C ₂ ) to the ON state is prevented from becoming unnecessarily long (# 7, # 11 steps).

In Fig. 4, the time (T _X ) from when the clutch engagement command is output
After passing, the operation signal is changed from the signal from the generator (I
The state is switched to f), and it is # 3, # 6, # 8.
Steps # 11 to # 11 are called control means (T). The sensor (S) is
The rotation of the gear (27) attached to the drive shaft (20a) of the wheel (20) is detected by the pickup type coil (28).

[Another embodiment]

The present invention may be applied to, for example, a multi-speed transmission system or provided in a transport vehicle other than the above-described embodiments, and the control means may be configured by hardware by combining a comparator, a logic gate and the like. Further, the signal (If) for setting the increase rate may be a non-linear type such as a curve, in addition to the linear type described above.

It should be noted that reference numerals are added to the claims for convenience of comparison with the drawings, but the present invention is not limited to the configurations of the accompanying drawings by the entry.

[Brief description of drawings]

The drawings show an embodiment of a hydraulic clutch device for traveling of a work vehicle according to the present invention. FIG. 1 is a block diagram of a control system, FIG. 2 is a schematic diagram of a transmission system for traveling, and FIG. FIG. 4 is a flowchart showing the operation, and FIG. 4 is a graph of an operation signal (current value) to the electromagnetic proportional pressure reducing valve at the start of traveling. (C ₁ ), (C ₂ ) …… hydraulic clutch for traveling, (T) …… control means,
(X) …… acceleration, (If) …… predetermined characteristic, (α) …… predetermined value.

Claims (1)

[Claims] 1. A hydraulic oil of a predetermined pressure is supplied to the traveling hydraulic clutches (C ₁ ) and (C ₂ ) after a clutch engagement command is issued,
Acceleration (X) in the acceleration direction of the aircraft due to the supply of the hydraulic oil
When a predetermined value (α) is reached while increasing, the traveling hydraulic clutch is increased at an increasing rate in accordance with a predetermined characteristic (If) set in advance based on the time point when the clutch engagement command is issued.
A hydraulic clutch device for traveling of a work vehicle, comprising a control means (T) for increasing the clutch internal pressure of (C ₁ ) and (C ₂ ).