A hydraulic control system for a harvester feed chamber and front feed roller test stand

Abstract

The present application relates to a kind of hydraulic control system of harvester feeding chamber and front feeding roller test bench, including plunger pump, input shaft, tensioning mechanism and loading mechanism, one end of input shaft is connected with plunger pump, the other end is used to connect bridge chain;Plunger pump is communicated with loading mechanism by oil supply pipeline, and loading mechanism is communicated with one end of loading return oil pipeline;Tensioning mechanism is communicated with oil supply pipeline by tensioning pipeline, and it is communicated with one end of tensioning return oil pipeline.The beneficial effects of the present application are simple structure, reasonable design, loading is carried out to bridge chain wheel, chain harrow fastener by hydraulic system, adjustable loading can be realized, various crop harvesting conditions can be simulated;In addition, automatic tensioning is carried out to conveying chain by cylinder tensioning, the pressure of tensioning cylinder is adjusted by proportional pressure reducing valve, and the tensioning speed is controlled by proportional flow valve, when conveying chain loosens, it can be compensated by cylinder reserved stroke, so as to realize the purpose of constant tensioning force.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of hydraulic control system, in particular to a kind of hydraulic control system of harvester feeding chamber and front feeding roller test bench. BACKGROUND

[0002] The main test items of harvester feeding chamber and front feeding roller test are bridge chain wheel chain jump test, chain harrow fastener clamping load test, bridge chain and chain wheel wear test and chain harrow fatigue structure test. At present, these tests are mainly carried out by empty running or actual field crop harvesting. When empty running, various load ratios are too small compared with actual, and problems cannot be effectively found in advance. Field test is greatly affected by crop planting season and crop regional distribution. In order to test, crops must be mature, and test must be carried out in planting area. Test is greatly affected by weather. If it rains, harvesting test cannot be carried out. At night, dew is heavy, and harvesting cannot be carried out. Test cycle is long, which leads to slow development progress.

[0003] At present, bridge chain wheel chain jump test, chain harrow fastener clamping load test, bridge chain and chain wheel wear test and chain harrow fatigue structure test need to be carried out by empty running or field crop harvesting after complete assembly of whole machine. The tension of bridge conveying chain is manually tensioned by tensioning wheel, and the tensioning process is not easy to control, which causes tensioning sometimes tight and sometimes loose. The existing technology has the following defects:

[0004] 1) Empty running cannot effectively find problems in advance;

[0005] 2) Field harvesting test is affected by region, operation season and weather, which prolongs development cycle and increases test cost;

[0006] 3) Empty running or field harvesting test must be carried out after complete assembly of whole machine, and part test cannot be carried out in advance;

[0007] 4) During field harvesting, other parts are damaged, and maintenance is required, which affects the efficiency of special test;

[0008] 5) Affected by weather, limit load simulation cannot be carried out, test is not comprehensive, and some potential faults cannot be found in advance;

[0009] 6) Bridge conveying chain tension is manually adjusted, which is troublesome and tensioning force is not easy to control. SUMMARY

[0010] The technical problem to be solved by the present application is to provide a kind of hydraulic control system of harvester feeding chamber and front feeding roller test bench, which aims at solving the problems in the prior art.

[0011] The technical solution of the present application to solve the above technical problem is as follows:

[0012] The hydraulic control system of a harvester feeding chamber and front feeding roller test bench comprises a plunger pump, an input shaft, a tensioning mechanism and a loading mechanism, one end of the input shaft is connected with the plunger pump, and the other end is used for connecting a bridge chain; the plunger pump is communicated with the loading mechanism through an oil supply pipeline, and the loading mechanism is communicated with one end of a loading return oil pipeline; the tensioning mechanism is communicated with the oil supply pipeline through a tensioning pipeline, and the tensioning mechanism is communicated with one end of a tensioning return oil pipeline.

[0013] The beneficial effects of the present application are that during operation, the input shaft rotates and drives the plunger pump to rotate, the plunger pump divides the output oil into two paths: one path of oil is sent to the tensioning mechanism to control the tensioning and loosening of the conveying chain, and the oil in the tensioning mechanism is returned through the tensioning return oil pipeline, and this oil path is called the conveying chain tensioning control loop; the other path of oil is sent to the loading mechanism to load the system, which is called the loading loop.

[0014] The present application has the advantages of simple structure and reasonable design, the bridge chain wheel and chain harrow fastener are loaded through the hydraulic system, the loading can be adjusted, various crop harvesting conditions can be simulated, in addition, the conveying chain is automatically tensioned through the tensioning mechanism to control the tensioning force and tensioning speed of the conveying chain, when the conveying chain loosens, the oil cylinder reserved stroke can be used for compensation, so that the purpose of constant tensioning force is achieved.

[0015] On the basis of the above technical scheme, the present application can also be improved as follows.

[0016] Further, the tensioning mechanism comprises a tensioning oil cylinder and a reversing valve, interfaces one, two, three and four are arranged on the reversing valve, the interface one can be communicated with the interface two, and the interface three can be communicated with the interface four, or the interface one can be communicated with the interface four, and the interface three can be communicated with the interface two;

[0017] The interface two is communicated with the rod cavity of the tensioning oil cylinder through a pipeline, and the interface four is communicated with the rodless cavity of the tensioning oil cylinder through a pipeline; the interface one is communicated with one end of the tensioning return oil pipeline, and the interface three is communicated with one end of the tensioning pipeline.

[0018] The beneficial effects of the above further scheme are that during operation, the input shaft rotates and drives the plunger pump to rotate, a part of the output oil of the plunger pump is sent to the tensioning oil cylinder through the reversing valve to control the tensioning and loosening of the conveying chain, and the oil in the tensioning oil cylinder is returned through the tensioning return oil pipeline; in addition, the reversing of the reversing valve realizes the change of the oil delivery direction of the oil at both ends of the tensioning oil cylinder, so that the tensioning and loosening of the conveying chain by the tensioning oil cylinder are realized, and the switching is convenient.

[0019] Further, the tensioning mechanism further comprises a tensioning flow valve, and the tensioning flow valve is respectively provided with an interface five and an interface six, and the interface five can be communicated with or disconnected from the interface six; the tensioning pipeline is provided with a notch, and the interface five and the interface six are respectively communicated with two ends of the notch.

[0020] The beneficial effect of the above further scheme is that when running, the amount of oil in the pipeline is controlled through the tensioning flow valve, so as to control the tensioning speed of the tensioning oil cylinder, and the structure is simple, reasonable in design, and convenient to adjust.

[0021] Further, a pressure reducing valve is fixedly installed on the tensioning pipeline corresponding to the position between the tensioning flow valve and the reversing valve, the pressure reducing valve is provided with a control interface one communicated with the internal valve core cavity thereof, and the control interface one is communicated with the tensioning oil return pipeline through a pipeline.

[0022] The beneficial effect of the above further scheme is that when running, the oil entering the tensioning flow valve is depressurized through the pressure reducing valve, so as to adjust the tensioning force of the tensioning oil cylinder.

[0023] Further, the loading mechanism comprises a loading overflow valve, and the loading overflow valve is provided with an interface seven and an interface eight, and the interface seven can be communicated with or disconnected from the interface eight; the interface seven and the interface eight are respectively communicated with one end of the oil supply pipeline and one end of the loading oil return pipeline; the loading overflow valve is further provided with a control interface two communicated with the internal valve core cavity thereof, and the control interface two is communicated with the oil supply pipeline through a pipeline.

[0024] The beneficial effect of the above further scheme is that when running, the input shaft rotates and drives the plunger pump to rotate, another part of the output oil of the plunger pump is sent to the loading overflow valve for system loading, and is returned through the loading oil return pipeline, so that adjustable loading can be realized, various crop harvesting working conditions can be simulated, the structure is simple, and the design is reasonable.

[0025] Further, a pressure sensor one is fixedly installed on the oil supply pipeline corresponding to the position between the loading overflow valve and the position where the tensioning pipeline and the oil supply pipeline are communicated.

[0026] The beneficial effect of the above further scheme is that the structure is simple, the design is reasonable, and the pressure regulated by the loading overflow valve is measured through the pressure sensor one, so that the measurement is convenient.

[0027] Further, a flow sensor and a pressure sensor two are fixedly installed on the loading oil return pipeline corresponding to the position between the other end of the loading oil return pipeline and the loading overflow valve.

[0028] The beneficial effect of the further scheme is that the structure is simple and reasonable in design, the oil flow of the loading overflow valve is measured by the flow sensor, the pressure of the oil flowing out of the loading overflow valve is measured by the second pressure sensor, the loading power of the input shaft is calculated according to the measured oil flow and pressure, and the loading power of the input shaft is adjusted by adjusting the opening pressure of the loading overflow valve, which is convenient to adjust.

[0029] Further, the flow sensor is located between the loading overflow valve and the second pressure sensor, and a heat dissipation mechanism is fixedly installed on the loading return oil pipeline corresponding to the position between the other end of the loading return oil pipeline and the second pressure sensor.

[0030] The beneficial effect of the further scheme is that the structure is simple and reasonable in design, the hydraulic system is cooled by the heat dissipation mechanism during operation, the pressure inside the hydraulic system is prevented from being too high, and the hydraulic system is ensured to operate safely.

[0031] Further, the heat dissipation mechanism includes a radiator and a heat dissipation fan, both ends of the heat dissipation fan are communicated with the loading return oil pipeline through pipelines, a one-way throttle valve is fixedly installed on the loading return oil pipeline corresponding to the position between the two ends of the heat dissipation fan and the loading return oil pipeline, and the one-way throttle valve is connected in parallel with a heat dissipation overflow valve.

[0032] The radiator is fixedly installed on the loading return oil pipeline and located between the other end of the loading return oil pipeline and the heat dissipation fan, and the radiator is also connected in parallel with a bypass pipeline, and a bypass valve is fixedly installed on the bypass pipeline.

[0033] The beneficial effect of the further scheme is that the hydraulic system is cooled by the radiator during operation, the pressure inside the hydraulic system is prevented from being too high, and the hydraulic system is ensured to operate safely; at the same time, the heat dissipation fan can accelerate the heat dissipation effect of the radiator, the heat dissipation effect is better, the structure is simple and reasonable in design.

[0034] Further, the oil supply pipeline is communicated with the loading return oil pipeline through a safety pipeline, and a safety overflow valve is fixedly installed on the safety pipeline.

[0035] The beneficial effect of the further scheme is that during operation, the safety overflow valve and the loading overflow valve are distributed in parallel, when the pressure inside the hydraulic system exceeds the set pressure value, the safety overflow valve is opened, part of the oil in the hydraulic system is returned through the safety overflow valve, pressure relief is realized, the pressure inside the hydraulic system is prevented from continuously rising, and thus damage to each component in the hydraulic system is avoided, the structure is simple and reasonable in design, and safe and reliable. BRIEF DESCRIPTION OF DRAWINGS

[0036] Fig. 1Fig. 1 is a schematic diagram of the overall structure of the present application;

[0037] Fig. 2 Fig. 2 is a schematic diagram of the structure of the loading mechanism of the present application when operating alone;

[0038] Fig. 3 Fig. 3 is a schematic diagram of the structure of the loading mechanism and the tensioning mechanism of the present application when operating simultaneously.

[0039] In the drawings, the components represented by the respective reference numerals are listed as follows:

[0040] 1, oil tank; 2, oil suction filter; 3, plunger pump; 4, input shaft; 5, high-pressure filter; 6, tensioning flow valve; 7, pressure reducing valve; 8, pressure sensor three; 9, reversing valve; 10, tensioning oil cylinder; 11, pressure sensor one; 12, loading overflow valve; 13, flow sensor; 14, pressure sensor two; 15, motor; 16, fan; 17, check valve; 18, radiator overflow valve; 19, throttle valve; 20, pressure sensor four; 21, temperature sensor one; 22, radiator; 23, temperature sensor two; 24, bypass valve; 25, safety overflow valve; 26, oil return filter; 27, oil drain tank one; 28, oil drain tank two. DETAILED DESCRIPTION

[0041] It should be noted that the embodiments in the present application and the features in the embodiments can be combined with each other without conflict.

[0042] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the purpose of facilitating the description of the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application. In addition, the terms "first", "second" and the like are only for the purpose of description and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features limited by "first", "second" and the like can explicitly or implicitly include one or more of the features. In the description of the present application, unless otherwise stated, the meaning of "a plurality of" is two or more.

[0043] In the description of the present application, it should be noted that unless specifically defined and limited otherwise, the terms "mounting", "connection", "connecting" should be understood in a broad sense, for example, it can be fixed connection, or detachable connection, or integrally connected; it can be mechanical connection, or electrical connection; it can be directly connected, or indirectly connected through intermediate medium, or the communication inside two elements. For those skilled in the art, the specific meaning of the above terms in the present application can be understood according to the specific circumstances.

[0044] The present application will be described in detail below with reference to the accompanying drawings and in conjunction with the embodiments.

[0045] Embodiment 1

[0046] As Figs. 1 to 3 shown, the present embodiment provides a hydraulic control system of a harvester feeding chamber and a front feeding roller test bench, which comprises a plunger pump 3, an input shaft 4, a tensioning mechanism and a loading mechanism, one end of the input shaft 4 is connected with the plunger pump 3, and the other end is used for connecting a bridge chain; the plunger pump 3 communicates with the loading mechanism through an oil supply pipeline, and the loading mechanism communicates with one end of a loading return oil pipeline; the tensioning mechanism communicates with the oil supply pipeline through a tensioning pipeline, and it communicates with one end of a tensioning return oil pipeline.

[0047] In operation, the input shaft 4 rotates and drives the plunger pump 3 to rotate, and the plunger pump 3 divides the output oil into two paths: one path of oil is sent to the tensioning mechanism to control the tensioning and loosening of the conveying chain, and the oil in the tensioning mechanism is returned through the tensioning return oil pipeline, and this oil path is called the conveying chain tensioning control loop; the other path of oil is sent to the loading mechanism to load the system, which is called the loading loop.

[0048] Preferably, the present embodiment further comprises an oil tank 1, and the oil inlet of the plunger pump 3 communicates with the oil tank 1 through an oil inlet pipeline, and a suction filter 2 is fixedly installed on the oil inlet pipeline. In operation, the oil from the oil tank 1 to the plunger pump 3 is filtered through the suction filter 2, which ensures the cleanliness of the oil entering the plunger pump 3 and prevents impurities or foreign matters from entering the plunger pump 3 and damaging the plunger pump 3.

[0049] Preferably, in the present embodiment, a high-pressure filter 5 is fixedly installed on the oil supply pipeline corresponding to the oil outlet of the plunger pump 3, which filters the impurities of the output oil of the plunger pump 3 and outputs clean oil to the downstream of the hydraulic system.

[0050] In addition, the above-mentioned high-pressure filter 5 is located on the part of the oil supply pipeline between the communication part of the plunger pump 3 and the tensioning pipeline and the oil supply pipeline.

[0051] Preferably, in the embodiment, the plunger pump 3 is provided with a drain port, which has two functions: one is to inject hydraulic oil before the plunger pump 3 operates to lubricate the plunger pump 3; the other is to cool the plunger pump 3; the drain port is directly connected to the drain tank 27 and is not connected in parallel to the oil tank 1 to prevent the drain circuit pressure from being too high, damaging the sealing elements of the plunger pump 3 and causing the plunger pump 3 to leak oil.

[0052] The embodiment has simple structure and reasonable design, loads the over-bridge chain wheel and the chain harrow fastener through the hydraulic system, can realize adjustable loading, simulates various crop harvesting working conditions, and automatically tensions the conveying chain through the tensioning mechanism to control the tensioning force and tensioning speed of the conveying chain, can compensate through the oil cylinder reserved stroke when the conveying chain is loose, and thus realizes the purpose of constant tensioning force.

[0053] Embodiment 2

[0054] On the basis of embodiment 1, in the embodiment, the tensioning mechanism comprises a tensioning oil cylinder 10 and a reversing valve 9, the reversing valve 9 is provided with an interface one, an interface two, an interface three and an interface four, the interface one can communicate with the interface two and the interface three can communicate with the interface four or the interface one can communicate with the interface four and the interface three can communicate with the interface two.

[0055] The interface two communicates with the rod cavity of the tensioning oil cylinder 10 through a pipeline, and the interface four communicates with the rodless cavity of the tensioning oil cylinder 10 through a pipeline; the interface one communicates with one end of a tensioning return pipeline, and the interface three communicates with one end of a tensioning pipeline.

[0056] When running, the input shaft 4 rotates and drives the plunger pump 3 to rotate, the plunger pump 3 sends part of the output oil to the tensioning oil cylinder 10 through the reversing valve 9 to control the tensioning and loosening of the conveying chain, and the oil in the tensioning oil cylinder 10 returns through the tensioning return pipeline; in addition, the reversing of the reversing valve 9 realizes the change of the oil delivery direction of the two ends of the tensioning oil cylinder, so as to realize the tensioning and loosening of the conveying chain by the tensioning oil cylinder 10, and the switching is convenient.

[0057] Preferably, in the embodiment, one end of the piston rod of the tensioning oil cylinder 10 is in transmission connection with the conveying sprocket of the conveying chain, for driving the conveying sprocket to move to tension the conveying chain.

[0058] Preferably, in the embodiment, the reversing valve 9 preferably adopts a three-position four-way electromagnetic reversing valve, which is convenient to reverse.

[0059] Embodiment 3

[0060] On the basis of embodiment 2, in the embodiment, the tensioning mechanism further comprises a tensioning flow valve 6, the tensioning flow valve 6 is respectively provided with an interface five and an interface six, the interface five can communicate with the interface six or be disconnected; the tensioning pipeline is provided with a gap, and the interface five and the interface six respectively communicate with two ends of the gap.

[0061] When in operation, the amount of oil in the pipeline is controlled by the tension flow valve 6, so as to control the tension speed of the tension cylinder 10, which is simple in structure, reasonable in design and convenient in adjustment.

[0062] Preferably, in the embodiment, the tension flow valve 6 is preferably a proportional flow valve.

[0063] Embodiment 4

[0064] On the basis of Embodiment 3, in the embodiment, a pressure reducing valve 7 is fixedly installed on the part of the tension pipeline corresponding to the part between the tension flow valve 6 and the reversing valve 9, the pressure reducing valve 7 is provided with a control interface one in communication with the internal valve core cavity thereof, and the control interface one is in communication with the tension return pipeline through a pipeline.

[0065] When in operation, the oil entering the tension flow valve 6 is depressurized by the pressure reducing valve 7, so as to adjust the tension force of the tension cylinder 10.

[0066] Preferably, in the embodiment, the pressure reducing valve 7 is preferably a proportional pressure reducing valve.

[0067] Preferably, in the embodiment, a pressure sensor three 8 is fixedly installed on the part between the tension pipeline and the pressure reducing valve 7 and the reversing valve 9, and the pressure sensor three 8 plays a role of displaying the set pressure of the pressure reducing valve 7.

[0068] Embodiment 5

[0069] On the basis of the above embodiments, in the embodiment, the loading mechanism comprises a loading overflow valve 12, the loading overflow valve 12 is provided with an interface seven and an interface eight, the interface seven can be in communication or disconnected with the interface eight; the interface seven and the interface eight are in communication with one end of the oil supply pipeline and one end of the loading return pipeline, respectively; the loading overflow valve 12 is further provided with a control interface two in communication with the internal valve core cavity thereof, and the control interface two is in communication with the oil supply pipeline through a pipeline.

[0070] When in operation, the input shaft 4 rotates and drives the plunger pump 3 to rotate, and another part of the output oil of the plunger pump 3 is sent to the loading overflow valve 12 for system loading, and is returned through the loading return pipeline, so as to realize adjustable loading, simulate various crop harvesting conditions, and have a simple structure and reasonable design.

[0071] Preferably, in the embodiment, the loading overflow valve 12 is preferably a proportional overflow valve.

[0072] Embodiment 6

[0073] On the basis of Embodiment 5, in the embodiment, a pressure sensor one 11 is fixedly installed on the part of the oil supply pipeline corresponding to the part between the loading overflow valve 12 and the part where the tension pipeline and the oil supply pipeline are in communication.

[0074] The scheme has simple structure and reasonable design, and the pressure regulated by the loading overflow valve 12 is measured by the pressure sensor 11, so the measurement is convenient.

[0075] Embodiment 7

[0076] In this embodiment, on the basis of any one of Embodiments 5 to 6, the loading return oil pipeline is provided with the flow sensor 13 and the pressure sensor 14 fixedly installed at intervals at a position corresponding to the other end of the loading return oil pipeline and the loading overflow valve 12.

[0077] The scheme has simple structure and reasonable design, and the oil flow of the loading overflow valve 12 is measured by the flow sensor 13, and the pressure of the oil flowing out of the loading overflow valve 12 is measured by the pressure sensor 14, and then the loading power (kW) is calculated according to the measured oil flow and pressure, and the loading power of the input shaft 4 is adjusted by adjusting the opening pressure of the loading overflow valve 12, so the adjustment is convenient.

[0078] Embodiment 8

[0079] In this embodiment, on the basis of Embodiment 7, the flow sensor 13 is located between the loading overflow valve 12 and the pressure sensor 14, and the loading return oil pipeline is provided with the heat dissipation mechanism fixedly installed at a position corresponding to the other end of the loading return oil pipeline and the pressure sensor 14.

[0080] The scheme has simple structure and reasonable design, and the heat dissipation mechanism is used to dissipate heat and cool the hydraulic system during the operation of the hydraulic system, so that the pressure inside the hydraulic system is prevented from being too large, and the safe operation of the hydraulic system is ensured.

[0081] Embodiment 9

[0082] In this embodiment, on the basis of Embodiment 8, the heat dissipation mechanism includes the radiator 22 and the heat dissipation fan, the two ends of the heat dissipation fan are respectively connected to the loading return oil pipeline through pipelines, the loading return oil pipeline is provided with the one-way throttle valve fixedly installed at a position corresponding to the two ends of the heat dissipation fan and the connection position of the loading return oil pipeline, and the one-way throttle valve is connected in parallel with the heat dissipation overflow valve 18.

[0083] The radiator 22 is fixedly installed on the loading return oil pipeline and located between the other end of the loading return oil pipeline and the heat dissipation fan, and the radiator 22 is also connected in parallel with the bypass pipeline, and the bypass valve 24 is fixedly installed on the bypass pipeline.

[0084] During the operation of the hydraulic system, the heat dissipation mechanism is used to dissipate heat and cool the hydraulic system, so that the pressure inside the hydraulic system is prevented from being too large, and the safe operation of the hydraulic system is ensured; at the same time, the heat dissipation fan can accelerate the heat dissipation of the radiator 22, so that the heat dissipation effect is better, the structure is simple, and the design is reasonable.

[0085] Preferably, in the embodiment, the one-way throttle valve comprises a one-way valve 17 and a throttle valve 19, and the loading return oil pipeline is provided with a gap, and the one-way valve 17 and the throttle valve 19 are arranged in parallel and communicate with both ends of the gap through pipelines.

[0086] Preferably, in the embodiment, the radiator overflow valve 18 is arranged in parallel with the one-way valve 17, and communicates with both ends of the gap through pipelines.

[0087] Preferably, in the embodiment, the radiator fan comprises a motor 15 and a fan 16, the motor 15 is arranged in parallel with the throttle valve 19, and communicates with both ends of the gap through pipelines; the fan 16 is fixedly installed on the driving end of the motor 15, and the motor 15 drives the fan 16 to rotate.

[0088] Preferably, in the embodiment, the motor 15 is provided with a second oil drain port, which communicates with a second oil drain tank 28 through a pipeline, and the oil in the motor 15 directly drains into the second oil drain tank 28 and does not enter the oil tank in parallel with other pipelines, so as to prevent the pressure of the oil drain circuit from being too high, damage the sealing elements of the motor 15, and cause the motor 15 to leak oil.

[0089] The one-way valve 17 and the throttle valve 19 form a one-way throttle valve, and the one-way throttle valve and the radiator overflow valve 18 jointly stabilize the pressure difference between both ends of the motor 15, so as to stabilize the rotation of the motor 15.

[0090] In addition, the radiator overflow valve 18 limits the pressure difference between both ends of the motor 15, so as to stabilize the rotation of the motor 15.

[0091] The throttle valve 19 is arranged in parallel with the motor 15, and by adjusting the flow of the throttle valve 19, the initial working flow required by the motor 15 can be adjusted, so as to achieve the purpose that the motor 15 does not work when the flow is low and the motor 15 starts to work when the flow is high.

[0092] Preferably, in the embodiment, the loading return oil pipeline is fixedly installed with a pressure sensor four 20 and a temperature sensor one 21 between the position corresponding to the throttle valve 19 and the position where the bypass pipeline and the loading return oil pipeline communicate.

[0093] In addition, the temperature sensor one 21 is used before the radiator 22, and plays a role of displaying the temperature of the oil before flowing through the radiator 22.

[0094] Preferably, in the embodiment, a temperature sensor 23 is fixedly installed at the position corresponding to the connection between the outlet of the oil supply pipeline and the outlet of the bypass pipeline of the radiator 22, and is used after the radiator 22 to display the temperature of the oil after flowing through the radiator 22, so as to compare the displayed temperature with the temperature displayed by the temperature sensor 21 to determine whether the heat dissipation effect of the radiator 22 meets the requirements.

[0095] Preferably, in the embodiment, the bypass valve 24 is set to be opened at a pressure of 5 Bar, and when the inlet pressure of the radiator 22 exceeds 5 Bar, the bypass valve 24 is opened to protect the radiator 22.

[0096] Embodiment 10

[0097] On the basis of the above-mentioned embodiments, in the embodiment, the oil supply pipeline is communicated with the loading return pipeline through a safety pipeline, preferably, the connection between the tensioning pipeline and the oil supply pipeline is communicated with the loading return pipeline through the safety pipeline, and a safety overflow valve 25 is fixedly installed on the safety pipeline.

[0098] During operation, the safety overflow valve 25 is distributed in parallel with the loading overflow valve 12, and when the pressure inside the hydraulic system exceeds the set pressure value, the safety overflow valve 25 is opened, part of the oil in the hydraulic system is returned through the safety overflow valve 25 to realize pressure relief, so as to prevent the pressure inside the hydraulic system from continuously rising, thereby avoiding damage to each component in the hydraulic system, and the structure is simple, reasonable, safe and reliable.

[0099] Preferably, in the embodiment, a return filter 26 is fixedly installed on the loading return pipeline at the position corresponding to the connection between the other end of the loading return pipeline and the safety pipeline and the loading return pipeline, and the return filter 26 filters the impurities in the hydraulic oil in the loading return pipeline.

[0100] The working principle of the present application is as follows:

[0101] During operation, the input shaft 4 rotates and drives the plunger pump 3 to rotate, the plunger pump 3 absorbs oil from the oil tank 1 through the oil absorption filter 2, and the oil is divided into three paths after passing through the high-pressure filter 5, one path controls the tensioning of the tensioning cylinder 10 to control the tensioning and loosening of the conveying chain, which is called the conveying chain tensioning control loop; the second path loads the system through the loading overflow valve 12, the loaded hydraulic oil drives the motor 15 to rotate, thereby driving the radiator fan 16 to rotate, providing power for the radiator, and then the hydraulic oil returns to the tank through the radiator 22, which is called the loading loop; the third path is the loop through the safety overflow valve 25, which is called the overflow loop.

[0102] (1) Conveying chain tensioning control loop:

[0103] When the tension flow valve 6 and the b1 electromagnet of the reversing valve 9 are powered at the same time, the tension state of the conveying chain is shown in Fig. 3 . The hydraulic oil enters the pressure reducing valve 7 through the tension flow valve 6, and the pressure reducing valve 7 reduces the pressure of the hydraulic oil and then delivers the hydraulic oil to the reversing valve 9. The pressure reducing valve 7 can infinitely adjust the output oil pressure, and then enters the rodless cavity of the tension cylinder 10 to push the piston rod of the tension cylinder 10 to tension the conveying chain, and the tension force is controlled by the pressure reducing valve 7;

[0104] When the tension force reaches the set value, the outlet pressure of the pressure reducing valve 7 reaches the set value, the pressure reducing valve 7 is closed, and no oil flows through the pressure reducing valve 7 (see Fig. 2 );

[0105] When the conveying chain wheel loosens, the pressure in the rodless cavity of the tension cylinder 10 decreases, the pressure reducing valve 7 opens, and continues to supply oil to the tension cylinder 10, and the piston rod of the tension cylinder 10 continues to tighten the tension wheel until the set pressure is reached and the pressure reducing valve 7 is closed. The pressure in the rodless cavity of the tension cylinder 10 is always stable, so that the output tension force of the tension cylinder 10 is stable and automatically tensioned;

[0106] When the a1 electromagnet of the reversing valve 9 is powered, the oil enters the rod cavity of the tension cylinder 10 to push the piston to recover, and at this time the tension wheel loosens and no longer provides tension to the conveying chain.

[0107] (2) Loading circuit:

[0108] The oil passes through the high-pressure filter 5 and passes through the loading overflow valve 12. The opening pressure of the loading overflow valve 12 is adjusted by adjusting the current of the loading overflow valve 12. When the hydraulic oil pressure before the loading overflow valve 12 reaches the set pressure, the loading overflow valve 12 is opened under the action of the hydraulic pressure, and the pressure sensor one 11 displays the hydraulic oil pressure before the loading overflow valve 12 at this time;

[0109] After the loading overflow valve 12 is opened, the hydraulic oil passes through the loading overflow valve 12 and then passes through the flow sensor 13. The flow sensor 13 displays the flow rate of the hydraulic oil flowing through the loading overflow valve 12. The pressure displayed by the pressure sensor two 14 and the flow rate displayed by the flow sensor 13 are used to calculate the corresponding power, which is the input shaft loading power. By adjusting the opening pressure of the loading overflow valve 12, the input shaft loading power can be adjusted;

[0110] The hydraulic oil flows through the flow sensor 13, passes through the throttle valve 19 and the motor 15, and due to the throttling effect of the throttle valve 19, the pressure before the motor 15 gradually rises. When the pressure difference between the front and back of the motor 15 reaches 120 Bar, the heat dissipation overflow valve 18 is opened, the pressure sensor two 14 displays the hydraulic oil pressure before the motor 15, and the pressure sensor four 20 displays the hydraulic oil pressure after the motor 15. The excess hydraulic oil reaches the downstream of the hydraulic system through the heat dissipation overflow valve 18, and the pressure difference between the two ends of the motor 15 is stabilized, so that the motor 15 works stably, and the motor 15 drives the fan 16 to work.

[0111] After passing through the motor 15, the hydraulic oil is combined with the oil passing through the throttle valve 19 and the heat dissipation overflow valve 18, and then enters the radiator 22. The pressure sensor four 20 displays the inlet pressure of the radiator 22, and the temperature sensor one 21 displays the oil temperature entering the inlet of the radiator 22. When the pressure exceeds the pressure set by the bypass valve 24, the bypass valve 24 is opened, and the oil flows to the downstream through the bypass valve 24 and is combined with the oil passing through the radiator 22. The temperature sensor two 23 displays the hydraulic oil temperature after the radiator 22. By observing the temperature difference between the temperature sensor one 21 and the temperature sensor two 23, the heat dissipation effect of the radiator 22 can be judged.

[0112] After heat dissipation, the hydraulic oil is filtered by the oil return filter 26 and returns to the hydraulic oil tank 1.

[0113] (3) Overflow circuit:

[0114] When the hydraulic system behind the loading overflow valve 12 is blocked or the like, the safety overflow valve 25 is opened when the pressure before the loading overflow valve 12 exceeds 375 Bar, and the system pressure is stabilized at 375 Bar, which plays the role of a safety valve to prevent the system pressure from continuously rising and damaging various components of the hydraulic system.

[0115] It should be noted that all the electronic components involved in the present application are of existing technology, and the above-mentioned components are electrically connected with the controller. The control circuit between the controller and each component is of existing technology.

[0116] The beneficial effects of the present application are:

[0117] 1. The conveying chain and the chain wheel and the chain harrow can be infinitely loaded, and the test of crops in the field is replaced;

[0118] 2. The test period is greatly shortened, which provides guarantee for the research and development progress;

[0119] 3. The conveying chain is automatically tensioned, and manual adjustment is not required;

[0120] 4. The test is free from the constraints of crop maturity season, region and weather, and can be carried out at any time, which provides guarantee for early problem detection.

[0121] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the present application can be implemented in other particular forms without departing from the spirit or essential characteristics of the present application. The presently disclosed embodiments are, therefore, to be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference to an item in the claims is to be construed as a disavowal of the support of that item by the other claims.

[0122] In addition, it should be understood that although the description herein is made on the basis of the embodiments, not every embodiment contains only one independent technical solution, and the description herein is made in this way only for the sake of clarity, and those skilled in the art should consider the description as a whole, and the technical solutions in each embodiment can also be properly combined to form other embodiments which can be understood by those skilled in the art.

[0123] The above description is only the preferred embodiment of the present application, and is not intended to limit the present application, and any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall be included in the protection scope of the present application.

Claims

1. A hydraulic control system for a harvester feed chamber and front feed roller test stand, characterized by: The tensioning mechanism includes a tensioning oil cylinder (10) and a reversing valve (9), the reversing valve (9) is provided with an interface one, an interface two, an interface three and an interface four, the interface one can be communicated with the interface two and the interface three can be communicated with the interface four or the interface one can be communicated with the interface four and the interface three can be communicated with the interface two. The interface two is communicated with the rod cavity of the tensioning oil cylinder (10) through a pipeline, the interface four is communicated with the rodless cavity of the tensioning oil cylinder (10) through a pipeline, the interface one is communicated with one end of the tensioning back oil pipeline, and the interface three is communicated with one end of the tensioning pipeline. The tensioning mechanism further includes a tensioning flow valve (6), the tensioning flow valve (6) is respectively provided with an interface five and an interface six, the interface five can be communicated with the interface six or disconnected; a notch is arranged on the tensioning pipeline, and the interface five and the interface six are respectively communicated with two ends of the notch. A pressure relief valve (7) is fixedly installed on the tensioning pipeline corresponding to the position between the tensioning flow valve (6) and the reversing valve (9), the pressure relief valve (7) is provided with a control interface one communicated with the valve core cavity inside the pressure relief valve (7), and the control interface one is communicated with the tensioning back oil pipeline through a pipeline. The tensioning oil cylinder (10) has a reserved stroke for compensating the tensioning force of the conveying chain when the conveying chain is loose. The loading mechanism includes a loading overflow valve (12), the loading overflow valve (12) is provided with an interface seven and an interface eight, the interface seven can be communicated with the interface eight or disconnected; the interface seven and the interface eight are respectively communicated with one end of the oil supply pipeline and one end of the loading back oil pipeline; the loading overflow valve (12) is further provided with a control interface two communicated with the valve core cavity inside the loading overflow valve (12), and the control interface two is communicated with the oil supply pipeline through a pipeline.

2. The harvester feedroom and front feedroll test stand hydraulic control system of claim 1 wherein: A pressure sensor one (11) is fixedly installed on the oil supply pipeline corresponding to the position between the loading overflow valve (12) and the tensioning pipeline and the oil supply pipeline.

3. The harvester feed shoe and front feed roller test stand hydraulic control system of claim 2, characterized in that: Flow sensors (13) and pressure sensor two (14) are fixedly installed on the loading back oil pipeline at intervals.

4. The harvester feed shoe and front feed roller test stand hydraulic control system of claim 2, characterized in that: The flow sensor (13) is located between the loading overflow valve (12) and the pressure sensor two (14), and a heat dissipation mechanism is fixedly installed on the loading back oil pipeline corresponding to the position between the other end of the loading back oil pipeline and the pressure sensor two (14).

5. The harvester feed shoe and front feed roller test stand hydraulic control system of claim 4, wherein: ​ 6. The harvester feed shoe and front feed roller test stand hydraulic control system of claim 5, wherein: The heat dissipation mechanism comprises a heat radiator (22) and a heat dissipation fan, two ends of the heat dissipation fan are communicated with the loading back oil pipeline through pipelines, a one-way throttle valve is fixedly installed on a position between the two ends of the heat dissipation fan communicated with the loading back oil pipeline, and a heat dissipation overflow valve (18) is connected in parallel with the one-way throttle valve; The heat radiator (22) is fixedly installed on the loading back oil pipeline and located between the other end of the loading back oil pipeline and the heat dissipation fan; the heat radiator (22) is further connected in parallel with a bypass pipeline, and a bypass valve (24) is fixedly installed on the bypass pipeline.

7. The harvester feed shoe and front feed roller test stand hydraulic control system of claim 1 wherein: The oil supply pipeline is communicated with the loading back oil pipeline through a safety pipeline, and a safety overflow valve (25) is fixedly installed on the safety pipeline.

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