A hydraulic lifting system for a tractor

Abstract

The application relates to a hydraulic lifting system for a tractor, which comprises an oil suction filter, an oil pump, an oil return filter, a safety valve, a main compensation valve, a pilot pressure reducing valve, a pilot safety valve, a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly and a multi-way valve group, wherein the oil suction filter is connected with the oil pump, the oil return filter, the pilot pressure reducing valve and the pilot safety valve respectively; the oil pump is connected with the safety valve, the main compensation valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly and the fourth valve assembly respectively; and the oil return filter is connected with the safety valve, the main compensation valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly, the fourth valve assembly and the multi-way valve group respectively. The application meets the requirement of complex working condition operation.

Description

Technical Field

[0001] This application relates to the field of pressure control, and more particularly to a hydraulic lifting system for tractors. Background Technology

[0002] The existing hydraulic lifting system for tractors cannot meet the complex operating conditions control requirements of a 100-horsepower tractor for rear suspension accessories, so it needs to be improved. Summary of the Invention

[0003] In order to solve the above-mentioned technical problems, or at least partially solve the above-mentioned technical problems, this application provides a hydraulic lifting system for tractors.

[0004] In a first aspect, this application provides a hydraulic lifting system for a tractor, comprising: a suction filter, an oil pump, a return filter, a safety valve, a main compensating valve, a pilot pressure reducing valve, a pilot safety valve, a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, and a multi-way valve group. The suction filter is connected to the oil pump, the return filter, the pilot pressure reducing valve, and the pilot safety valve. The oil pump is connected to the safety valve, the main compensating valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly, and the fourth valve assembly. The return filter is connected to the safety valve, the main compensating valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly, the fourth valve assembly, and the multi-way valve group.

[0005] Preferably, the first valve assembly includes: a first compensation valve, which is connected to the return oil filter and the main compensation valve respectively.

[0006] Preferably, the first valve assembly further includes a first shuttle valve, which is connected to the safety valve and the first compensation valve respectively.

[0007] Preferably, the first valve assembly further includes a first pressure reducing valve, which is connected to the safety valve and the first shuttle valve respectively.

[0008] Preferably, the first valve assembly further includes a second pressure reducing valve, which is connected to both the safety valve and the first pressure reducing valve.

[0009] Preferably, the first valve assembly further includes: a first quick-connect fitting, which is connected to the first pressure reducing valve and the second pressure reducing valve respectively.

[0010] Preferably, the second valve assembly includes a second compensation valve, which is connected to the return oil filter and the main compensation valve, respectively.

[0011] Preferably, the second valve assembly further includes a second shuttle valve, which is connected to the safety valve and the second compensation valve respectively.

[0012] Preferably, the second valve assembly further includes a third pressure reducing valve, which is connected to both the safety valve and the second shuttle valve.

[0013] Preferably, the second valve assembly further includes a fourth pressure reducing valve, which is connected to the safety valve and the third pressure reducing valve respectively.

[0014] The technical solutions provided in this application have the following advantages compared with the prior art: The hydraulic lifting system for tractors provided in this application meets the requirements of complex working conditions and operational flexibility. Attached Figure Description

[0015] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments consistent with the invention and, together with the description, serve to explain the principles of the invention.

[0016] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, for those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] Figure 1 This is a schematic diagram of a hydraulic lifting system for a tractor provided in an embodiment of this application. Detailed Implementation

[0018] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, not all embodiments. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] like Figure 1This application provides a hydraulic lifting system for a tractor, comprising: an oil suction filter 1, an oil pump 2, a return oil filter 3, a safety valve 4, a main compensating valve 5, a pilot pressure reducing valve 6, a pilot safety valve 7, a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, and a multi-way valve group. The oil suction filter 1 is connected to the oil pump 2, the return oil filter 3, the pilot pressure reducing valve 6, and the pilot safety valve 7. The oil pump 2 is connected to the safety valve 4, the main compensating valve 5, the pilot pressure reducing valve 6, the pilot safety valve 7, the first valve assembly, the second valve assembly, the third valve assembly, and the fourth valve assembly. The return oil filter 3 is connected to the safety valve 4, the main compensating valve 5, the pilot pressure reducing valve 6, the pilot safety valve 7, the first valve assembly, the second valve assembly, the third valve assembly, the fourth valve assembly, and the multi-way valve group.

[0020] In this embodiment, the first valve assembly includes: a first compensating valve 8.1, a first shuttle valve 8.2, a first pressure reducing valve 8.3, a second pressure reducing valve 8.4, and a first quick-connect fitting 8.5. The first compensating valve 8.1 is connected to the return oil filter 3 and the main compensating valve 5, respectively. The first shuttle valve 8.2 is connected to the safety valve 4 and the first compensating valve 8.1, respectively. The first pressure reducing valve 8.3 is connected to the safety valve 4 and the first shuttle valve 8.2, respectively. The second pressure reducing valve 8.4 is connected to the safety valve 4 and the first pressure reducing valve 8.3, respectively. The first quick-connect fitting 8.5 is connected to the first pressure reducing valve 8.3 and the second pressure reducing valve 8.4, respectively.

[0021] In this embodiment, the second valve assembly includes: a second compensating valve 9.1, a second shuttle valve 9.2, a third pressure reducing valve 9.3, a fourth pressure reducing valve 9.4, and a second quick-connect fitting 9.5. The second compensating valve 9.1 is connected to the return oil filter 3 and the main compensating valve 5, respectively. The second shuttle valve 9.2 is connected to the safety valve 4 and the second compensating valve 9.1, respectively. The third pressure reducing valve 9.3 is connected to the safety valve 4 and the second shuttle valve 9.2, respectively. The fourth pressure reducing valve 9.4 is connected to the safety valve 4 and the third pressure reducing valve 9.3, respectively. The second quick-connect fitting 9.5 is connected to the third pressure reducing valve 9.3 and the fourth pressure reducing valve 9.4, respectively.

[0022] This application provides a hydraulic lifting system for a tractor, which consists of four circuits: a bypass flow regulation control circuit, a pilot control circuit, a pressure compensation feedback circuit, and a lifting circuit. These four circuits are intertwined and interdependent, forming a perfectly unified whole. The specific control principle is as follows: (1) Bypass flow regulation control circuit: Oil pump 2 delivers oil to multi-way valve group 12 through suction filter 1. Pressure oil is delivered to main compensation valve 5 through P port of multi-way valve group 12. Main bypass valve 5 can automatically adjust according to the actual flow requirements of multi-way valve and lifter. Excess flow is delivered to T port of multi-way valve group 12 through main bypass valve 5, and then returned to oil tank through return oil filter 3.

[0023] (2) Pilot control circuit: The pilot control circuit is used to control the output of the three-way multi-way valve, that is, the switching of different positions 1 / 0 / 2, F, and four positions. The pressure oil passes through the P port of the multi-way valve group 12 and then to the pressure reducing valve 6 for pilot pressure control, which is used to adjust the pilot pressure. The pilot pressure oil then reaches the first compensation valve 8.1 and the first shuttle valve 8.2, the second compensation valve 9.1 and the second shuttle valve 9.2, and the third compensation valve 10.1 and the third shuttle valve 10.2 of the three-way multi-way valve output. When one of the channels needs to be reversed, the first compensation valve 8.1 is energized and the first shuttle valve 8.2 is de-energized. At this time, the pilot control oil passes through the first compensation valve 8.1 and reaches the lower end of the valve stem 8.6. The main valve stem 8.6 moves upward against the spring force, that is, it is adjusted from position 0 to position 1. The pressure oil is delivered from the P port through the first compensation valve 8.1 and then through the valve stem 8.6 to the first quick-change connector 8.5 to realize the output of oil.

[0024] (3) Pressure Compensation Feedback Oil Circuit: This oil circuit is used to control the output flow of the three-way multi-way valve, enabling on-demand supply. Excess flow is returned to the oil tank through the main compensation valve 5. For example, when the first compensation valve 8.1 is energized and the first shuttle valve 8.2 is de-energized, the output flow of the valve stem 8.6 is determined by the displacement of the valve stem 8.6. At the same time, the pressure oil is also fed back to the main compensation valve 5 through the first shuttle valve 8.2 to adjust the flow supplied by the oil pump to the valve stem 8.6. Excess flow is returned to the oil tank through the main compensation valve 5. The control principle is the same for the other two circuits.

[0025] (4) Lifting Circuit: This circuit is used to control the extension and retraction of the lifting cylinder 11.7. Pressurized oil is delivered to the compensating valve 11.1 through the P port of the multi-way valve group 12. When the lifting cylinder needs to extend, the solenoid valve 11.4 is energized, and the pressurized oil is delivered to the large chamber of the lifting cylinder 11.7 after passing through the solenoid valve 11.4 and the check valve 11.5, and the lifting cylinder 11.7 is in the extended state. At the same time, the pressurized oil is also fed back to the main compensating valve 5 through the shuttle valve 11.2, and the supply flow can be controlled according to the lifting speed. Excess flow is returned to the housing.

[0026] (5) When the lifting cylinder needs to retract, the solenoid valve 11.3 is energized, and the oil in the large chamber of the lifting cylinder 11.7 returns to the housing through the solenoid valve 11.3 under the load; the speed at which the lifting cylinder 11.7 descends is controlled by the solenoid valve 11.3.

[0027] The hydraulic lifting system for tractors provided in this application meets the requirements of complex working conditions and operational flexibility.

[0028] It should be noted that, in this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0029] The above description is merely a specific embodiment of the present invention, enabling those skilled in the art to understand or implement the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features claimed herein.

Claims

1. A hydraulic lifting system for a tractor, characterized in that, include: The system comprises an oil suction filter, an oil pump, a return oil filter, a safety valve, a main compensating valve, a pilot pressure reducing valve, a pilot safety valve, a first valve assembly, a second valve assembly, a third valve assembly, a fourth valve assembly, and a multi-way valve group. The oil suction filter is connected to the oil pump, the return oil filter, the pilot pressure reducing valve, and the pilot safety valve. The oil pump is connected to the safety valve, the main compensating valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly, and the fourth valve assembly. The return oil filter is connected to the safety valve, the main compensating valve, the pilot pressure reducing valve, the pilot safety valve, the first valve assembly, the second valve assembly, the third valve assembly, the fourth valve assembly, and the multi-way valve group. The first valve assembly includes: a first compensating valve, a first shuttle valve, a first sub-pressure reducing valve, a second sub-pressure reducing valve, and a first quick-connect coupling. The first compensating valve is connected to the return oil filter and the main compensating valve, the first shuttle valve is connected to the safety valve and the first compensating valve, the first sub-pressure reducing valve is connected to the safety valve and the first shuttle valve, the second sub-pressure reducing valve is connected to the safety valve and the first sub-pressure reducing valve, and the first quick-connect coupling is connected to the first sub-pressure reducing valve and the second sub-pressure reducing valve. The second valve assembly includes: a second compensating valve, a second shuttle valve, a third sub-pressure reducing valve, and a fourth sub-pressure reducing valve. The second compensating valve is connected to the return oil filter and the main compensating valve, respectively. The second shuttle valve is connected to the safety valve and the second compensating valve, respectively. The third sub-pressure reducing valve is connected to the safety valve and the second shuttle valve, respectively. The fourth sub-pressure reducing valve is connected to the safety valve and the third sub-pressure reducing valve, respectively. The hydraulic lifting system for the tractor consists of the following four circuits: bypass flow regulation control circuit, pilot control circuit, pressure compensation feedback circuit, and lifting circuit. The bypass flow regulation control circuit is as follows: the oil pump delivers oil to the multi-way valve group through the oil suction filter, the pressurized oil is delivered to the main compensation valve through the P port of the multi-way valve group, the main bypass valve automatically adjusts according to the actual required flow of the multi-way valve and the lifter, and the excess flow is delivered to the T port of the multi-way valve group through the main bypass valve, and then returned to the oil tank through the return oil filter. The pilot control circuit is as follows: The pilot control circuit is used to control the output of the three-way multi-way valve. The pressure oil passes through the P port of the multi-way valve group to the pressure reducing valve controlled by the pilot pressure, which is used to adjust the pilot pressure. The pilot pressure oil reaches the first compensation valve and the first shuttle valve, the second compensation valve and the second shuttle valve, and the third compensation valve and the third shuttle valve of the three-way multi-way valve output. When one of the channels needs to be reversed, the first compensation valve is energized and the first shuttle valve is de-energized. At this time, the pilot control oil passes through the first compensation valve to the lower end of the valve stem. The valve stem moves upward against the spring force, that is, it is adjusted from position 0 to position 1. The pressure oil passes through the first compensation valve and then through the valve stem from the P port to the first quick-connect coupling to realize the output of the oil. The pressure compensation feedback loop is as follows: This loop controls the output flow of the three-way multi-way valve, enabling on-demand supply. Excess flow is returned to the oil tank through the main compensation valve. When the first compensation valve is energized and the first shuttle valve is de-energized, the flow rate output by the valve stem is determined by the valve stem displacement. Simultaneously, pressure oil is also fed back to the main compensation valve through the first shuttle valve to regulate the flow rate supplied by the oil pump to the valve stem. Excess flow is returned to the oil tank through the main compensation valve. The second compensation valve, the second shuttle valve, the third compensation valve, and the third shuttle valve operate on the same control principle. The lifting circuit is as follows: This circuit is used to control the extension and retraction of the lifting cylinder; pressurized oil is delivered to the compensating valve through the P port of the multi-way valve group; when the lifting cylinder needs to extend, the solenoid valve is energized, and pressurized oil is delivered to the large chamber of the lifting cylinder after passing through the solenoid valve and the check valve, and the lifting cylinder is in the extended state; at the same time, the pressurized oil is also fed back to the main compensating valve through the shuttle valve, which can control the supply flow according to the lifting speed, and the excess flow is returned to the housing.

Images