JPH064667Y2 - Hydraulic system for work vehicle - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION (a) Field of Industrial Application The present invention relates to a working vehicle equipped with a hydraulic actuator for operating a working portion and a hydraulic actuator for traveling operation, and more specifically, to enable these actuators to be operated simultaneously. The structure of the hydraulic system.

(B) Conventional technology Generally, a working vehicle, such as a combine, is equipped with a pretreatment unit for cutting grain culms, and a side clutch / brake device for changing or stopping the course of the machine body. -The brake device is operated by each actuator installed in the main oil passage to which the hydraulic oil is supplied by the hydraulic pump, and the operator switches the actuators in a timely manner to operate the pretreatment unit and the side clutch / brake respectively. They are working to cut grain culms. Then, when the aircraft reaches the end of the field during the mowing operation, the operator turns the aircraft, but at this time, the pretreatment unit rises from a lowered position near the field scene to a predetermined height and contacts the field scene. To prevent such problems.

(C) Problems to be solved by the device However, in the above-mentioned conventional hydraulic device, the actuator for the pretreatment part and the actuator for the side clutch / brake device are simply connected in parallel to the main oil passage, and therefore, there is a problem in turning. If the hydraulic lever and the side clutch lever are operated at the same time, the hydraulic pressure of the main circuit will drop due to the drain of the side clutch switching valve, and the pretreatment section cannot be raised.
In addition, a problem such as a slow response may occur.

(D) Means for Solving the Problem The present invention is intended to solve the above problems, and as shown in FIG. 1, for example, as shown in FIG. For example, hydraulic actuators 7A, A, 2 for operating side clutch and side brake
Switching valves V1 and V for controlling 1L and 21R respectively
2, V3 and V4 are respectively connected to the main oil passage 31 in parallel. Furthermore, the hydraulic actuators for traveling operation A, 21L
It is characterized in that relief valves 45 and 49 are installed in parallel in the oil passages 38 and 46 on the downstream side of the switching valves V3 and V4 for supplying pressure oil to the 21R.

(E) Operation Based on the above configuration, when the machine body 2 is turned to reach the end of the field during the mowing work by the working vehicle C, the switching valves V3 and V4 are switched and the traveling operation (for side clutch operation and Pressure oil is sent to the actuators A, 21L and 21R for side brake operation to operate the traveling operation unit. At this time, these actuators A, 21L and 21L
Excess flow after piston movement in 21R is relief valve 4
Since the throttle operation is performed by 5, 5 respectively, the main oil passage 3
Since the hydraulic pressure of No. 1 is not lowered and the switching valves V1 and V2 for operating the working unit operating hydraulic actuator 7A (for example, the preprocessing unit actuator) are connected in parallel to the main oil passage 31, The actuator 7A is the hydraulic actuator A for traveling operation, 21L.
The work unit 7 (for example, the pretreatment unit) operates smoothly even if it is operated simultaneously with 21R (for example, the side clutch or side brake actuator).

(F) Embodiment An embodiment according to the present invention will be described below with reference to the drawings.

The combine C has a sprocket S as shown in FIG.
Airframe 2 supported by a crawler 1 driven by
The engine 3 is mounted on one side of the machine body 2 on the rear side, the driver's seat 5 is arranged on the front side, and the Glen tank 6 is installed between them.
An automatic thresher is installed on the other side. Furthermore, Aircraft 2
A pre-processing unit 7 is arranged in the front of the vehicle so as to be able to move up and down, and the side clutch / brake device (A), (21L, 21R) (see FIG. 1) is housed in the lower portion of the machine body 2 behind it. A mission case 9 is installed. The driver's seat 5 has the driver's seat frame 1 on the body frame 2a.
0 is fixed, and a step surface 11 is fixed to the front portion of the frame 10. A seat 12 is installed in the rear part of the frame 10 via a seat frame, and a valve body 13 is placed and fixed on the driver's seat frame 10 below the seat 12. The valve body 13 has a block 13a in which a predetermined oil passage is formed, and the valves and filters detailed in FIG. 1 are arranged on the block 13a.

In addition, an operation console 15 is provided above the front of the driver's seat frame 10.
Is erected, and the upper surface of the operation console 15 is the operation panel 1
It is 6. A monolever 17 is erected on the operation panel 16, and various operation switches,
A meter and an indicator lamp are provided, and a side clutch lever 19 is rotatably installed. The monolever 17 is constructed so as to be able to swing in two steps only in the left-right direction, controls the side clutch solenoid valve V3 in conjunction with the movement of the first step thereof, and also operates the single piston 20 and the left-right cylinder 20L. , 20R actuates the side clutch actuator A to disconnect the left and right side clutches, and controls the side brake solenoid valve V4 in synchronism with the movement of the second stage of the side clutch. Actuator 21
The left and right side brakes are braked and operated by operating L and 21R. A hydraulic lever 22, an FR stepless speed change lever 23, and an auxiliary speed change lever are arranged on a side operation panel installed adjacent to the inside of the body of the driver's seat 5. The valve V for manually lowering the pretreatment section of the valve body is interlocked with the tilting operation of the hydraulic lever 22.
2 and the raising valve V1 are controlled, whereby the actuator 7A for the pretreatment unit 7 can be controlled to move up and down (see FIG. 1). Further, the F / R continuously variable transmission lever 23 is supported so as to be swingable in the left-right direction and biased in a standing posture so as to be swingable in the front-rear direction of the machine body, and therefore is neutral along the crank-shaped guide hole. It is possible to operate over a forward drive range and a reverse drive range that extend from the position to the front and back.

Next, the hydraulic circuit will be described with reference to FIG.

The hydraulic pump P communicates with a flow divider 30 provided in the oil passage 29 through a filter F, and the flow divider 30 connects the oil passage 29 to a variable pressure main oil passage 31 and a constant pressure main oil passage 32. It is divided into two. Then, in the variable pressure system main oil passage 31, a switching valve V11 located at the uppermost stream of the variable pressure system main oil passage 31 for operating the grain barrel actuator 6A of the Glen tank.
Are connected in series, and further, unload solenoid valves V6, V7, pretreatment section raising valve V1, pretreatment section lowering valve V2, side clutch solenoid valve V3, side brake solenoid valve V4 and none. Solenoid valves V5 for operating the gear shift actuator 25A are connected in parallel, and a forward clutch actuator FA, a reverse clutch actuator RA, and a parking brake actuator BA are respectively connected to the constant pressure main oil passage 32. F / R for switching operation
The clutch valve V8 is connected, and the unloading valves V9 and V10 and the check valve 33 are also interposed.

On the other hand, the unloading valves V6 and V7 are solenoid valves for respective actuating devices such as valves V1 and V2 for raising and lowering the pretreatment section on the downstream side of the valve V11 for frying cylinders of the variable pressure main oil passage 31. Are arranged in parallel on the upstream side of, and are installed so as to flow the pressure oil on the downstream side of the main oil passage 31 or from the main oil passage 31 toward the tank T under the control thereof. Further, from the variable pressure system main oil passage 31, a pretreatment section raising valve V1, a side clutch solenoid valve V3,
The parallel oil passages 35, 36, 37, 39 for supplying pressure oil to the side brake solenoid valve V4 and the continuously variable transmission solenoid valve V5 are connected from the respective switching valve side to the main oil passage 31. Check valves 40, 41, 42, 43 for preventing backflow are provided. Further, from the side clutch solenoid valve V3 to the left and right cylinders 20 of the side clutch actuator A.
One variable relief valve 45 is connected in parallel to the oil passage 38 communicating with each of the L and 20R via a surplus oil passage 44 and a check valve 50. The oil pressure of the oil passage 31 is configured to be variablely throttled. Further, similar to the solenoid valve V3, the side brake solenoid valve V4
Actuator for braking and operating the left and right brakes from
One variable relief valve 49 is connected in parallel to the oil passage 46 communicating with each of the L and 21R via the surplus oil passage 47 and the check valve 50.
The left and right brakes are operated by the lever 1 by operating the variable flow of the excess flow sent to the oil passage 47 by the valve 49 in conjunction with
A braking pressure corresponding to the tilting angle of 7 is applied.

Since the present embodiment is configured as described above, when the operator operates the monolever 17 in either the left or right direction during the combine operation, the side clutch solenoid valve V3 is switched and the side clutch actuator A is operated. Release one side clutch. At this time, the pressure oil supplied from the main oil passage 31 to the actuator A via the solenoid valve V3 is sent to the left cylinder 20L or the right cylinder 20R to move the single piston 20 by a predetermined stroke to operate the actuator A. However, since the surplus flow after the movement of the piston 20 is sent to the surplus oil passage 44 and the variable relief valve 45 performs the variable throttle operation, the hydraulic pressure in the main oil passage 31 does not drop below a predetermined pressure.

Further, when the mono-lever 17 is further tilted, the side brake solenoid valve V4 is switched and pressure oil is sent to the left side brake actuator 21L or the right side brake actuator 21R. And
After moving the pistons of these actuators 21L and 21R by a predetermined stroke, the pressure oil is sent to the surplus flow oil passage 47 as a surplus flow, but the variable relief valve 49 controls the surplus flow by variable throttling operation, and the side flow is controlled. The brakes (21L and 21R) are operated to a braking pressure according to the tilt angle of the lever 17, and the hydraulic pressure in the main oil passage 31 is maintained in a stable state without dropping.

Therefore, since the hydraulic pressure in the main oil passage 31 does not drop even while the side clutch actuator A and the side brake actuators 21L and 21R are operating, the hydraulic pressure for the pretreatment unit connected in parallel to the oil passage 31 is reduced. The actuator 7A can operate smoothly without causing a problem even if it is operated simultaneously with the side clutch and side brake actuators A, 21L and 21R.

The cylinders 20L or 20R, 21L or 21R of the side clutch and side brake actuators
During the predetermined stroke, the pressure oil is sent to the cylinder, so that the pressure in the main oil passage 31 may drop and the pretreatment section 7 may not be able to rise. However, the stroke of the cylinder is short and the pretreatment It does not have a great influence on the rise of part 7. Further, when controlling the variable pressure main oil passage 31, the unloading valves V6 and V7 are switched simultaneously with the control of the respective valves, and the hydraulic pressure is applied to the variable pressure main oil passage 31.

(G) Effect of the Invention As described above, according to the present invention, the hydraulic actuators 7A, A, 21L.
Switching valves V1, V2, V for controlling 1R respectively
Since V3 and V4 are respectively connected in parallel to the main oil passage 31, the working unit 7 (for example, the pretreatment unit) and the traveling operation unit (A),
(21L and 21R) (for example, side clutch and side brake) can be operated simultaneously. Further, oil passages 38, 4 downstream of the switching valves V3, V4 for supplying pressure oil to the traveling operation hydraulic actuators A, 21L, 21R.
Since the relief valves 45 and 49 were installed in parallel in 6,
When the traveling parts (A) and (21L · 21R) (for example, side clutch and side brake) are operated, the pistons of the hydraulic actuators A, 21L and 21R (for example, side clutch actuator and side brake actuator) have moved by a predetermined stroke. By operating the relief valves 45 and 49 to throttle the remaining excess flow, it is possible to stably maintain the hydraulic pressure in the main oil passage 31 without lowering the hydraulic pressure, and thereby the traveling operation parts (A), (21L, 21R). )
Hydraulic actuator 7A for operating the working part while operating the
(For example, a hydraulic actuator for the pretreatment unit) can be supplied with a predetermined pressure of oil to smoothly operate the working unit 7 (for example, the pretreatment unit). Therefore, when the end of the field is reached during the cutting operation, the work can be performed. Section 7 and traveling operation section (A), (21L ・ 21R)
It is possible to quickly and smoothly turn the machine by simultaneously operating and to improve the operation feeling by the operator.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram according to the present invention, and FIG. 2 is a side view showing the entire combine thereof. 7 ... Working unit (pretreatment unit), 7A ... Working unit operating hydraulic actuator (Pretreatment unit hydraulic actuator), 21L
21R, A ... Traveling hydraulic actuators (left and right side brake actuators, side clutch actuators), 31 ... Main oil passage (variable pressure main oil passage), 3
8, 46 ... Oil passage, 45, 49 ... (Variable) relief valve, C ... Working vehicle (combine), V1, V2, V3
V4 ... Switching valve (pretreatment section raising valve, pretreatment section lowering valve, side clutch solenoid valve, side brake solenoid valve).

Claims (2)

[Scope of utility model registration request] 1. A hydraulic system for a working vehicle comprising switching valves for controlling a hydraulic actuator for operating a working portion and a hydraulic actuator for traveling, respectively, wherein the switching valves are connected in parallel to a main oil passage, respectively. A hydraulic system for a working vehicle in which a relief valve is installed in parallel in an oil passage downstream of the switching valve that supplies pressure oil to the traveling hydraulic actuator. 2. A practical use in which the working unit operating hydraulic actuator is a pre-processing unit hydraulic actuator, the traveling operating hydraulic actuator is a side clutch and side brake hydraulic actuator, and the working vehicle is a combine. A hydraulic system for a work vehicle according to claim 1 of the new model registration claim.