JP2000312504A - Device for lifting and lowering working machine in tractor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide the subject device capable of constituting a lifting and lowering part having a high rigidity with a simple structure, and enhancing the adaptability to a small size tractor, or the like, by pivotally supporting a lift arm on the midway parts of right and left lower props constituting a guard frame through supporting shafts so as to be freely turned. SOLUTION: Right and left lower props 5a are stood on a transmission case 10 installed in the rear part of a machine body 1c in a tractor having a lifting and lowering part 2 of a working machine having a hydraulic cylinder 2a at the rear part of the machine body 1c. An upper prop 5c having a reversed U-shape is supported by the right and left lower props 5a so that the angle may be freely adjusted, and a portal guard frame 5 is constituted in the rear direction of a seat 4b. A lift arm 16 constituting the lifting and lowering part 2 of a working machine connected to the hydraulic cylinder 2a is pivotally supported by the midway parts of the right and left lower props 5a constituting the guard frame 5 through supporting shafts 50 so as to be freely turned.

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 and is provided with a working unit such as a tilling device to perform a lifting operation.

[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, and the rear end of the hydraulic cylinder is connected to a lift arm also provided on the transmission case to raise and lower the tilling device.

[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. Also, if a hydraulic switching valve is configured together with a hydraulic cylinder, the size of the device will increase, occupying installation space, and if a lift arm or the like is provided on the transmission case below the seat, the seat will be at an even higher position, and installation on a small tractor etc. It has problems such as difficulty.

[0004]

According to the present invention, there is provided a tractor working machine lifting / lowering device comprising a working machine lifting / lowering section 2 having a hydraulic cylinder 2a at a rear portion of a body 1c.
Left and right lower supports 5 are mounted on a transmission case 10 provided at the rear of the fuselage.
a, and a column-shaped guard frame 5 is provided behind the seat 4b while an inverted U-shaped upper support 5c is supported on the left and right lower supports so as to be adjustable in angle, while a hydraulic cylinder 2a is provided. A lift arm 16 constituting a lifting unit of the working machine connected to the support frame 50 is rotatably pivoted to a middle part of the left and right lower columns 5a constituting the guard frame 5 via a support shaft 50 thereof. I have.

[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 mounting a work machine (not shown) such as a tilling device on the tractor 1. ) A control unit 4 including an engine unit 3, a steering wheel 4 a, and a seat 4 b is arranged from 1 c on the front side.
A hydraulic cylinder 2a constituting the elevating unit 2 and a hydraulic switching valve 2b thereof are externally attached to a transmission (transmission case) 10 formed below the machine base 1c and below the machine base 1c.

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. The guard frame 5 fits the lower end base of the lower support 5a into the upper bracket 12 and fixes the lower support 5a. The base of the lift arm 16 that pivotally supports the other end of the hydraulic cylinder 2a via a mounting pin 2P is pivotally supported by a support shaft 50, and has an inverted U-shaped upper support at the upper end via an angle adjusting portion 5b. 5c is supported so that the angle can be adjusted.

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]

According to the present invention, the lift arm 16 constituting the elevating part of the working machine connected to the hydraulic cylinder 2a is connected to the seat 4
(b) Since it is pivotally supported on the rear gate-shaped guard frame 5 via the support shaft 50, the lift arm 16 for raising and lowering the working machine is separately provided on the transmission case 10 as in the related art.
It is possible to use the guard frame 5 for protecting the operator directly without using a supporting portion to rotatably support the supporting frame. Therefore, the highly rigid lifting and lowering portion 2 can be formed with a simple structure. It can be configured at low cost. Also, since the guard frame 5 has its lower support 5a erected on the transmission case 10 and is arranged behind the seat 4b, the lift arm 16 attached to the guard frame 5 is also located behind the seat 4b. Since there is no need to provide a space for installing the lift arm 16 and the like below the seat 4b, there is an advantage that the adaptability to a small tractor or the like having a low seat position is increased.

[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 (traveling work machine) 1c Machine base (body) 2 Elevating part 2a Hydraulic cylinder 2b Hydraulic switching valve 4b Seat 5 Guard frame 5a Lower support 5c Upper support 5c 10 Transmission (transmission case) 16 Lift arm

Claims (1)

[Claims] 1. A tractor comprising a lifting unit (2) of a working machine provided with a hydraulic cylinder (2a) at a rear part of a body (1c). A support (5a) is erected, and an inverted U-shaped upper support (5c) is supported on the left and right lower supports so as to be adjustable in angle, and a seat (4b) is provided.
While forming a gate-shaped guard frame (5) behind the
A lift arm (16), which constitutes an elevating part of the working machine connected to the hydraulic cylinder (2a), is connected via a support shaft (50) to a middle part of the left and right lower supports (5a) which constitute the guard frame (5). A tractor working machine elevating device, which is pivotally supported by a pivot.