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CN-122014843-A - Hydraulic control system and power shift tractor

CN122014843ACN 122014843 ACN122014843 ACN 122014843ACN-122014843-A

Abstract

The application belongs to the technical field of agricultural machinery, and discloses a hydraulic control system and a power shift tractor, wherein the hydraulic system comprises a working accessory hydraulic circuit and an accessory controller; the hydraulic pump unit is used for pumping oil from the gearbox and comprises a first pump and a second pump, a first oil way is hydraulically connected between an oil return port of the accessory controller and an oil return port of the PTO clutch control valve, and a second oil way is hydraulically connected between the oil return port of the PTO clutch control valve and the gearbox, so that the oil return oil of the accessory controller and the oil return oil of the PTO clutch control valve are converged to the gearbox to serve as oil slivers. The application can improve and promote the working performance of the hydraulic control system, avoid the valve member from being impacted by back pressure, prolong the service life of the valve member, and has large lubrication flow, more complete lubrication of the clutch in the gearbox and more loose selection of the clutch model.

Inventors

  • MA XIAOWEN
  • HE WEI
  • HUANG ZHEN
  • CHEN HAO
  • ZHANG KAIHUA

Assignees

  • 中联农业机械股份有限公司

Dates

Publication Date
20260512
Application Date
20251231

Claims (10)

  1. 1. A hydraulic control system for a tractor, the hydraulic control system comprising: a working accessory hydraulic circuit comprising an accessory controller; a gearbox (1) is internally provided with a PTO clutch (11) and a reversing clutch; The control valve group comprises a PTO clutch control valve (8) for on-off controlling the PTO clutch (11) and a reversing control valve (9) for on-off controlling the reversing clutch; A hydraulic pump group for pumping oil from the gearbox (1) and comprising a first pump (2) for pumping hydraulic oil towards an oil inlet of the accessory controller and a second pump (3) for pumping hydraulic oil towards an oil inlet of the PTO clutch control valve (8) and an oil inlet of the reversing control valve (9); the first oil way (L0) is hydraulically connected between an oil return port of the accessory controller and an oil return port of the PTO clutch control valve (8); The second oil way (L1) is hydraulically connected between an oil return port of the PTO clutch control valve (8) and the gearbox (1) so that the oil return oil of the accessory controller and the oil return oil of the PTO clutch control valve (8) are converged to the gearbox (1) to serve as lubricating oil of the PTO clutch (11) and the reversing clutch.
  2. 2. The hydraulic control system according to claim 1, characterized in that the return oil hydraulic pressure of the reversing control valve (9) is connected into the second oil circuit (L1) such that the return oil of the reversing control valve (9) merges into the gearbox (1) as the lubricating oil.
  3. 3. The hydraulic control system according to claim 1, characterized in that a radiator (7) is provided in the first oil passage (L0).
  4. 4. The hydraulic control system according to claim 1, characterized in that the pumped oil of the oil outlet of the second pump (3) is connected in parallel to the oil inlet of the PTO clutch control valve (8) and the oil inlet of the reversing control valve (9) after filtration via a pressure oil filter (6).
  5. 5. The hydraulic control system according to claim 4, characterized in that an oil suction filter (4, 5) is arranged in the oil suction line between the hydraulic pump group and the gearbox (1).
  6. 6. The hydraulic control system according to any one of claims 1 to 5, characterized in that the working attachment hydraulic circuit includes a steering hydraulic circuit in which a steering controller (14) as the attachment controller is provided; The first oil path (L0) comprises a steering oil return oil path which is hydraulically connected between an oil return port of the steering controller (14) and an oil return port of the PTO clutch control valve (8).
  7. 7. The hydraulic control system according to claim 6, characterized in that the working implement hydraulic circuit comprises a lifting hydraulic circuit in which a lifting multiplex valve (17) is provided as the implement controller; the first oil way (L0) further comprises a lifting oil return oil way which is hydraulically connected between an oil return port of the lifting multi-way valve and an oil return port of the PTO clutch control valve (8).
  8. 8. The hydraulic control system according to claim 7, characterized in that the working attachment hydraulic circuit comprises a chassis control hydraulic circuit in which a chassis control valve (19) is provided as the attachment controller; The first oil way (L0) further comprises a chassis oil return oil way which is hydraulically connected between an oil return port of the chassis control valve (19) and an oil return port of the PTO clutch control valve (8).
  9. 9. The hydraulic control system according to claim 8, characterized in that an on-off valve (20) is provided in each of the lift return oil passage and the chassis return oil passage.
  10. 10. A power shift tractor, characterized in that it comprises a hydraulic control system according to any one of claims 1-9.

Description

Hydraulic control system and power shift tractor Technical Field The application belongs to the technical field of agricultural machinery, and particularly relates to a tractor and a hydraulic control system thereof. Background As shown in fig. 1, in the existing tractor, common oil is contained in a gearbox, after return oil of a steering controller (for short, a steering gear) passes through a radiator, a reversing valve and a PTO clutch control valve are controlled, and finally lubrication flow is provided for a PTO clutch and a reversing clutch in the gearbox through return oil of the PTO clutch control valve. When the lubrication oil supply mode is adopted, the lubrication flow of the reversing clutch and the PTO clutch is provided by the steering pump, once the provided lubrication flow is insufficient, the service lives of the reversing clutch and the PTO clutch are reduced, and meanwhile, the oil temperature is increased to influence the gearbox and the whole common oil hydraulic system. Further, the types of the reversing clutch and the PTO clutch used in the transmission are limited, and only a clutch having a small required lubrication flow rate can be selected. Disclosure of Invention In order to overcome the defects or shortcomings, the application discloses a hydraulic control system and a power shift tractor, so as to improve and promote the working performance of the hydraulic control system. To achieve the above object, the present application provides a hydraulic control system for a power shift tractor, the hydraulic system including: a working accessory hydraulic circuit comprising an accessory controller; A gearbox, in which a PTO clutch and a reversing clutch are arranged; the control valve group comprises a PTO clutch control valve for on-off controlling the PTO clutch and a reversing control valve for on-off controlling the reversing clutch; a hydraulic pump group for pumping oil from the gearbox and comprising a first pump for pumping hydraulic oil towards an oil inlet of the accessory controller and a second pump for pumping hydraulic oil towards an oil inlet of the PTO clutch control valve and an oil inlet of the reversing control valve; the first oil way is hydraulically connected between an oil return port of the accessory controller and an oil return port of the PTO clutch control valve; And the second oil way is hydraulically connected between the oil return port of the PTO clutch control valve and the gearbox, so that the oil return oil of the accessory controller and the oil return oil of the PTO clutch control valve are converged to the gearbox to serve as lubricating oil of the PTO clutch and the reversing clutch. In some embodiments, the return oil of the reversing control valve is hydraulically connected to the second oil passage, so that the return oil of the reversing control valve merges into the gearbox as the lubricating oil. In some embodiments, a radiator is disposed in the first oil passage. In some embodiments, the pumped oil of the oil outlet of the second pump is connected in parallel to the oil inlet of the PTO clutch control valve and the oil inlet of the reversing control valve after being filtered by a hydraulic oil filter. In some embodiments, an oil suction filter is disposed in an oil suction path between the hydraulic pump unit and the gearbox. In some embodiments, the working attachment hydraulic circuit includes a steering hydraulic circuit having a steering controller therein as the attachment controller; the first oil way comprises a steering oil return oil way which is hydraulically connected between an oil return port of the steering controller and an oil return port of the PTO clutch control valve. In some embodiments, the working implement hydraulic circuit includes a lift hydraulic circuit having a lift multi-way valve as the implement controller disposed therein; The first oil way further comprises a lifting oil return oil way which is hydraulically connected between the oil return port of the lifting multi-way valve and the oil return port of the PTO clutch control valve. In some embodiments, the working implement hydraulic circuit includes a chassis control hydraulic circuit having a chassis control valve therein as the implement controller; the first oil way further comprises a chassis oil return oil way which is hydraulically connected between an oil return port of the chassis control valve and an oil return port of the PTO clutch control valve. In some embodiments, on-off valves are respectively arranged in the lifting oil return oil path and the chassis oil return oil path. In addition, the application also provides a power shift tractor which comprises the hydraulic control system. In the power shift tractor and the hydraulic control system thereof, the single pump is additionally arranged to provide control oil for the PTO clutch control valve and the reversing control valve, instead of connecting the return oil of the hydraulic circu