JPH10117506A - Work machine elevating and lowering device for tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the work machine elevating and lowering device of a tractor capable of utilizing a hydraulic switching valve in common even for the tractors of different specifications. SOLUTION: The hydraulic cylinder 2a of the tractor provided with the elevating and lowering part 2 of a work machine provided with the hydraulic cylinder 2a on the rear part of a machine body 1c and the hydraulic switching valve 2b for operating the hydraulic cylinder 2a is provided between a transmission case 10 for constituting the machine body 1c and a lift arm 16 pivotally supported by a column 5a erected on the transmission case 10 and the hydraulic switching valve 2b is separated from the hydraulic cylinder 2a and installed at the appropriate part of the machine body 1c.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a lifting and lowering device for a working machine, which is mounted on a rear portion of a tractor, such as a tilling device, and is operated to move up and down.

[0002]

2. Description of the Related Art Conventionally, as shown in Japanese Utility Model Publication No. 47-10021, a working machine elevating device for a tractor is equipped with a tilling device and a hydraulic cylinder of an elevating unit for raising and lowering, and a hydraulic pressure for switching the hydraulic cylinder. The switching valve and the switching valve are integrally formed on the transmission case.

[0003]

As disclosed in the above publication, when the hydraulic cylinder and the hydraulic switching valve are integrally formed, for example, the hydraulic switching valve is provided together with the hydraulic cylinder for each of various tractors having different horsepower and handling specifications. Since it has to be manufactured, the hydraulic switching valve cannot be used for another model, and there is a problem that the configuration becomes complicated and the cost increases. Further, when the hydraulic switching valve is configured together with the hydraulic cylinder, the size of the device becomes large, so that there is a problem that it takes up installation space and it is difficult to install it on a small tractor.

[0004]

According to the present invention, there is provided a lifting and lowering device for a working machine for a tractor, comprising a lifting and lowering portion of a working machine having a hydraulic cylinder 2a at a rear portion of a body 1c, and a hydraulic switching valve 2b for operating the hydraulic cylinder 2a. The hydraulic cylinder 2a is provided between a transmission case 10 constituting the machine body 1c and a lift arm 16 pivotally supported on a support 5a provided on the transmission case 10 and a hydraulic switch is provided. The valve 2b is separated from the hydraulic cylinder 2a so as to be installed at an appropriate position on the body 1c. Further, the support column 5a is characterized in that it is a guard frame that stands upright behind the control section.

[0005]

Embodiments of the present invention will now be described with reference to the drawings. 1 is an elevating unit 2 formed at the rear of the fuselage
A tractor (running work machine) capable of performing various works such as tilling work by attaching a work machine (not shown) such as a tilling device to the tractor 1. The tractor 1 has a machine base (machine body) having front wheels 1a and rear wheels 1b. 1) A control unit 4 including an engine unit 3, a steering wheel 4a, and a seat 4b is arranged from the front on 1c, and a transmission (transmission case) 10 formed below the seat 4b and at the rear of the machine base 1c. Hydraulic cylinder 2a constituting the elevating unit 2 and its hydraulic switching valve 2
b and the like are externally assembled.

The transmission case 10 has a rear end provided with a PTO shaft 10P for transmitting a working machine, and a rear axle case (support case) 11 integrally formed on both left and right sides for supporting the rear wheel shaft 1b. An upper bracket 12 for pivotally supporting the hydraulic cylinder 2a via mounting pins 2P is provided on the upper surface of the left and right support cases 11, and a lower bracket 15 for pivotally supporting the lower link 13 via mounting pins 2R on the lower surface. It is fixed detachably by screwing.

Reference numeral 5 denotes a guard frame which is erected in the form of a gate behind the seat 4b.
Is fixedly fitted in the lower end base of the lower support 5a in the upper bracket 12 and has a hydraulic cylinder 2
The support arm 50 pivotally supports the base of the lift arm 16 that pivotally supports the other end of the support arm 2a via the mounting pin 2P. Adjustably supported.

As shown in FIG. 3, both ends of the support shaft 50 are rotatably mounted on cylindrical metal parts 51 formed on left and right lower supports 5a, 5a. The lift arm 16 is integrally protruded rearward near the inside of 5a. In addition, by connecting the distal end of the lift arm 16 and an intermediate portion of the lower link 13 with a lift rod 17, the lifting unit 2 has a three-point link mechanism, similarly to a conventional tractor.

The hydraulic switching valve 2b is connected to the seat 4
The hydraulic cylinder 2a is compactly installed below the transmission cylinder 10 by utilizing the upper surface space of the transmission case 10 and is switched by an elevation lever (not shown).
Is expanded and contracted by pressurized oil so that the working unit can be smoothly moved up and down via the elevating unit 2. By configuring the tractor working machine elevating device as described above, it is only necessary to change the hydraulic cylinder 2a for the tractors having different sizes and specifications while also using the hydraulic switching valve 2b, thereby reducing costs. In addition, since the hydraulic switching valve 2b and the hydraulic cylinder 2a are configured separately from each other, the hydraulic cylinder 2a can be installed in a highly rigid state with a simple mechanism with respect to the support case 11. Can be.

[0010]

The hydraulic switching valve 2b and the hydraulic cylinder 2a
By separately installing the hydraulic pressure control valve 2b and the airframe 1c, the hydraulic switching valve 2b can be shared and used for tractors having different specifications, so that the manufacturing cost of the tractor can be reduced. In addition, the above-mentioned hydraulic cylinder 2a
By interposing a lift arm 16 provided on a transmission case 10 and a column 5 erected on the transmission case 10, a highly rigid elevating unit can be configured with a simple structure. It can also serve as a guard frame for the control unit 4.

[Brief description of the drawings]

FIG. 1 is a side view of a tractor.

FIG. 2 is a rear view of FIG.

FIG. 3 is a sectional view of a main part showing a mounting structure of the lift arm.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 Tractor (working machine) 1c Machine base (body) 2 Elevating part 2a Hydraulic cylinder 2b Hydraulic switching valve 5 Guard frame 5a Prop 10 Transmission (transmission case) 11 Support case 16 Lift arm

Claims (2)

[Claims] 1. A tractor comprising a lifting / lowering part 2 of a working machine having a hydraulic cylinder 2a at a rear portion of a body 1c and a hydraulic switching valve 2b for operating the hydraulic cylinder 2a, the hydraulic cylinder 2a being connected to the body 1c. Between the transmission case 10 and the lift arm 16 pivotally supported by the column 5a erected on the transmission case 10, and the hydraulic switching valve 2b is separated from the hydraulic cylinder 2a so that the machine body 1c is properly positioned. Tractor lifting and lowering device installed on the tractor. 2. The tractor working machine lifting / lowering device according to claim 1, wherein the support column 5a is a guard frame that stands upright behind the control section.