RU2634950C1 - Rear hinged device of agricultural tractor - Google Patents

Abstract

FIELD: agriculture.

SUBSTANCE: rear hinged device of an agricultural tractor comprises lower links (1) and an central upper link (7). The lower links (1) comprise adjustable hooks (4) with replaceable hinges (12). The central upper link (7) comprises a helical pair (8) with the possibility of adjusting the length of the central top link (7) in the range from 580 to 1,020 mm. Side reactive links (13) comprise damping devices (19) with locks (23) and helical pairs (17, 18) with the possibility of adjusting the length of the suspension axis (28) in the range from 825 to 1,100 mm.

EFFECT: versatility of working with hinged working equipment due to the use of an adjustable lever system with the necessary adjustment range, compensation of lateral loads arising during the tractor operation in the unit with hinged working equipment, due to the use of side reaction links with damping devices in the design.

8 dwg

Description

The present invention relates to "three-point" rear mounted attachments designed for aggregation of wheeled agricultural tractors with various mounted working equipment (implements), in particular with standard size NU-2 and NU-3 implements (hereinafter, the sizes of the rear mounted device are indicated in accordance with GOST 10677 -2001), but can be extended to tools of other sizes, including non-standard ones.

A hinged device is known that contains an upper, two lower longitudinal rods with extensions, a hook bracket with a fork and a hook (SU 648153, AB 59/042, publ. 02.25.1979).

The closest analogue (prototype) to the proposed invention is a hinged device containing upper and lower rods (RU 2132118, АВВ 59/04, publ. 06/27/1999).

The disadvantages of the known inventions include the impossibility of fully aggregating the tractor with implements designed to work with mounted devices of various sizes, subject to all requirements for geometric characteristics, safety and stability of power characteristics. In particular, in the transport position, the lifting height of the attachments may not be sufficient for safe transport. The possibility of adjustment (adjustment) of the working position of the elements of the mounted implements, for example, the angle of inclination of the plow to the soil surface, is not guaranteed. Due to the lack of shock absorbing devices in the attachment, the lateral forces arising from the operation of the tractor in the unit with attachments are transmitted to the tractor skeleton. Due to the presence of such shortcomings, the operating efficiency of the mounted implements and the tractor is reduced.

The task to which the invention is directed is to increase the versatility of the use of an agricultural tractor through the use of implements of various sizes and reduce the load on the skeleton of the tractor.

The technical result of the invention is the creation of a rear mounted attachment that provides versatility to work with mounted attachments made in the sizes NU-2 and NU-3, through the use of a reconfigurable linkage system with the necessary adjustment range, as well as compensating for lateral loads that occur when the tractor is operating in unit with mounted working equipment, due to the use of lateral draft rods with shock absorbing devices in the design.

The technical result is ensured by the fact that in the rear mounted attachment of an agricultural tractor, comprising lower links and a central upper link, according to the invention, the lower links include adjustable hooks with interchangeable joints, the central upper link contains a screw pair with the possibility of adjusting the length of the central upper link in the range from 580 to 1020 mm, and the lateral reaction rods introduced into the design with shock absorbing devices are equipped with screw pairs, and the size of the screw pairs allows adjustment of the suspension axis length from 825 mm to 1100 mm.

The essence of the technical solution is illustrated by the following drawings:

FIG. 1 - rear attachment, side view,

FIG. 2 - rear attachment, top view,

FIG. 3 - lower draft

FIG. 4 - side jet thrust,

FIG. 5 - rear attachment, connecting triangle,

FIG. 6 is a loading diagram of a rear attachment,

FIG. 7 - calculation results of the load capacity of the rear attachment with adjustments for size NU-2,

FIG. 8 - calculation results of the load capacity of the rear attachment with adjustments for size NU-3,

where the following notation is given:

1 - lower draft

2 - front end of lower link 1

3 - the rear end of the lower rod 1

4 - hook

5 - clamp

6 - cavity

7 - central upper thrust

8 - screw pair

9 - upper lever

10 - hydraulic cylinder

11 - vertical brace

12 - interchangeable joint

13 - lateral jet thrust

14 - lower draft

15 - upper draft

16 - clamp

17 - screw pair

18 - screw pair

19 - shock absorbing device

20 - cylinder

21 - piston

22 - spring

23 - latch

24 - cover

25 - tabs

26 - mount

27 - connecting triangle

28 - suspension axis

29 - supporting surface.

The rear attachment of an agricultural tractor consists of two lower rods 1 (Fig. 1), each of which has front and rear ends 2 and 3 (Fig. 3), respectively, hook 4, lock 5 and cavity 6 for installing hook 4, the central upper rods 7 with a screw pair 8, two upper levers 9, two hydraulic cylinders 10, two vertical braces 11, interchangeable hinges 12, intended for fastening working equipment (not shown), and two side jet rods 13 (Fig. 2). The vertical brace 11 consists of a lower link 14, an upper link 15 and a clamp 16, while the upper link 14 and a clamp 16 form a screw pair 17. The lateral reaction rod 13 includes a screw pair 18 (Fig. 4), a shock-absorbing device 19, structurally consisting of a cylinder 20, a piston 21, a spring 22 and a latch 23, made in the form of a cover 24 with a slot fixed on the cylinder 20, and protrusions 25 on the piston 21, from the side of the latch 23, the cover 24 has a mount 26 to the tractor frame (not shown) . The connecting triangle 27 (Fig. 5) is formed by lines connecting the connecting points of the lower links 1 and the central upper link 7, the line connecting the connecting points of the lower links 1 forms the axis of the suspension 28.

The device operates as follows:

Setting the rear attachment for a certain size is carried out by adjusting the following elements: the hooks 4 of the lower links 1 can move along the cavities 6, while the hook 4 is fixed with a latch 5, the lengths of the side reaction rods 13, the central upper link 7 and the vertical braces 11 are changed due to changes in the screwing depth of screw pairs 8, 18 and 17, respectively. Moreover, the length L ₁ has the ability to adjust from 580 to 1020 mm, and the length L of the axis of the suspension 28 has the ability to adjust in the range from 825 to 1100 mm.

For example, the adjustment of the rear attachment to the frame size NU-2 according to GOST 10677-2001 is carried out in the following order:

- set the lower link hooks to the front position, fix the clamps;

- by rotating the screw pairs 17 on the side jet rods 13 to establish the required length L of the axis of the suspension 28;

- lower the hydraulic cylinders 10;

- by rotating the clamps 16 of the vertical braces 11 to establish the required minimum height H from the supporting surface 29 to the axis of the suspension 28;

- install replaceable hinges 12 of standard size NU-2 in hooks 4;

- by rotating the screw pair 8, adjust the length of the central upper link 7 to ensure the required height B of the connecting triangle 27.

Setting the rear attachment to frame size NU-3 is carried out similarly, but the hooks 4 of the lower rods 1 are moved to the extreme rear position and replaceable hinges 12 corresponding to frame size NU-3 are installed in the hooks 4.

The shock-absorbing device 19 operates as follows: when the tractor is operating in an aggregate with attached working equipment (for example, with a plow), the cover 24 of the latch 23 is in the raised position (Fig. 1) so that the protrusion 25 is not engaged with the cover 24, due to this the spring 21 of the shock absorbing device 19 has the ability to compress under the influence of some axial force applied to the lateral thrust rod 13. In the event of lateral forces on the attached work equipment, the force is transmitted through the lower link 1 to the lateral thrust active traction 13, in which the piston 21 compresses the spring 22. The compression force of the spring 22 compensates for the lateral forces arising on the mounted implements, which significantly reduces the lateral load transmitted to the tractor frame from the implement. With the working equipment raised up, the cover 24 is lowered onto the lateral thrust rod 13 and engages with the protrusion 25, blocks the movement of the piston 21, and therefore the possibility of changing the length of the lateral thrust rod 13 when side forces occur (for example, due to inertia or lateral forces wind), which increases safety when driving a tractor with working equipment raised up.

When designing the proposed rear attachment, an analysis of its effectiveness was performed based on mathematical modeling of load tests.

When modeling, the change in effort at the control point was estimated depending on the change in the position (stroke) of the lower rods 1. The distance C to the load measuring point on the aggregated implement was taken in 3 versions (Fig. 6):

1) 0 mm (at the rear ends of the 3 lower rods 1),

2) 610 mm from the rear ends 3 of the lower rods 1,

3) 1220 mm from the rear ends of the 3 lower rods 1.

The analysis was carried out for ideal working conditions of the rear attachment, characterized by the absence of friction in the joints of the linkage system and the absence of losses in the tractor hydraulic system (the hydraulic system gives out 100% of its power).

According to the results of the analysis of the graphs (Fig. 7, Fig. 8), we can conclude that the kinematic diagram of the rear attachment ensures a constant increase in the force generated by the tractor’s hydraulic system necessary to extract from the soil and lift the working equipment to the transport position regardless of the position of the center of gravity equipment for both frame size NU-2 and frame size NU-3.

Claims (1)

An agricultural tractor rear mounted attachment comprising lower links and a central upper link, characterized in that the lower links include adjustable hooks with interchangeable joints, the central upper link contains a helical pair with the possibility of adjusting the length of the central upper link in the range from 580 to 1020 mm, and the fact that it has side reaction rods containing shock absorbing devices with clamps and screw pairs with the possibility of adjusting the length of the suspension axis in the range from 825 to 1100 mm.

Images