Hydraulic system for driving rake to be folded synchronously

Abstract

The utility model relates to a hydraulic system for driving a rake to fold synchronously, a bidirectional balance valve of the hydraulic system comprises a first throttle valve and a second throttle valve, pressures of first oil ports of the two throttle valves are throttling control pressures, the two throttle valves are connected with a one-way valve in parallel, and the first oil port of the first throttle valve is connected with a pump when located at the left position of a multi-way valve; a second oil port of the first throttling valve is connected with rodless cavities of the two oil cylinders after passing through the flow distributing and collecting valve, a first oil port of the second throttling valve is connected with the oil tank when located at the left position of the multi-way valve, a second oil port of the second throttling valve is connected with rod cavities of the two oil cylinders respectively, and a first oil port of the first throttling valve is connected with the oil tank when located at the right position of the multi-way valve. The first oil port of the second throttling valve is connected with the pump when located at the right position of the multi-way valve, and the first oil port of the first throttling valve and the first oil port of the second throttling valve are sealed through the middle position of the multi-way valve. Through the application of the flow distributing and collecting valve, the driving rake is forced to be synchronous in the folding and unfolding processes, and the problem of asynchronism caused by different loads on the two sides in the market is solved.

Description

Technical Field

[0001] The utility model relates to an eraser, in particular to a hydraulic system for synchronously folding a driving rake containing magnetic materials, belonging to a stationery item. Background Art

[0002] At present, a commonly used hydraulic system for a folding rake is to control the folding mechanism with a two-way hydraulic control check valve. As Figure 1 shown, the V1 and V2 ports are connected to the working ports of a multi-way valve. The control oils of the two hydraulic control check valves respectively come from the pressure of another check valve. The C1 port is connected to the small chamber of the luffing cylinder, and the C2 port is connected to the large chamber of the luffing cylinder. The overflow valve in the hydraulic control check valve protects the large chamber of the cylinder from overpressure and damage.

[0003] The specific working principle of the system is as follows: When the left path of the reversing valve works, the oil from the pump enters the multi-way valve and then enters the V2 port. It enters the large chamber of the cylinder through the left check valve inside, and the cylinder extends to achieve the folding function. The oil in the small chamber returns to the tank through the C1 port, enters the right check valve to the V1 port, and then returns to the tank from the multi-way valve.

[0004] When the right path of the reversing valve works, the oil from the pump enters the multi-way valve and then enters the V1 port. It enters the small chamber of the cylinder through the right check valve inside, and the cylinder retracts to achieve the unfolding function. The oil in the large chamber returns to the tank through the C2 port, enters the right check valve to the V2 port, and then returns to the tank from the multi-way valve.

[0005] When the reversing valve is in the neutral position, there is no control pressure through the hydraulic control check valve, and the check valve locks the oil passage to keep the cylinder stationary.

[0006] This kind of hydraulic system has a simple structure, is easy to implement, and has a low cost. However, because the gravity negative load changes continuously during the descent, it causes the action to shake when unfolding the folding rake, with large noise and vibration. Moreover, because the loads on both sides and the resistance of the hydraulic pipelines are different, there is no forced synchronization function, so the folding and unfolding actions cannot be completely synchronized, resulting in poor handling feel and aesthetic sense.

[0007] Figure 2 Another hydraulic system is provided, which uses a two-way balance valve to control the folding mechanism. The schematic diagram of the balance valve is as shown. The pressures of the V1 and V2 ports respectively serve as the control pressures for the opposing throttle ports, and the opening amount of the throttle port is controlled by the change of pressure to achieve the functions of decelerating and stabilizing the speed during descent. The V1 and V2 ports are connected to the working ports of the multi-way valve, the C1 port is connected to the small chamber of the luffing cylinder, and the C2 port is connected to the large chamber of the luffing cylinder.

[0008] The specific working principle of the system is as follows: When the left path of the reversing valve works, the oil from the pump enters the multi-way valve and then enters the V2 port. It enters the large chamber of the cylinder through the left check valve inside, and the cylinder extends to achieve a smooth folding function. The oil in the small chamber returns through the C1 port. At this time, the throttle port has been opened by the opposing control pressure, and the oil in the C1 port passes through the throttle port to the V1, and then returns to the tank from the multi-way valve.

[0009] When the right path of the reversing valve is working, the oil from the pump enters the multi-way valve and then into port V1. It enters the small chamber of the oil cylinder through the right check valve inside, and the oil cylinder retracts to achieve the smooth unfolding function. The oil returning from the small chamber passes through port C2. At this time, the throttle port has been opened by the opposing control pressure. The oil from port C2 passes through the throttle port to V2 and then returns to the fuel tank from the multi-way valve.

[0010] When the reversing valve is in the neutral position, there is no control pressure through the throttle port, and the check valve and the throttle port lock the oil passage to keep the oil cylinder stationary.

[0011] This hydraulic system, through the application of a two-way balance valve, solves the problem of unstable descent during the folding and unfolding of the driving harrow, avoids jitter and noise, and improves the operation comfort and the service life of the machine. However, due to different loads on both sides and different hydraulic pipeline resistances, and without a forced synchronization function, the folding and unfolding actions cannot be completely synchronized, resulting in poor operating feeling and aesthetic feeling. Summary of the Utility Model

[0012] The purpose of the present utility model is to provide a hydraulic system for synchronous folding of a driving harrow to solve the problem that the hydraulic system for synchronous folding of the driving harrow in the prior art cannot be completely synchronized during the folding and unfolding actions due to the lack of a forced synchronization function.

[0013] To solve the above problems, the hydraulic system for synchronous folding of the driving harrow involved in the present utility model adopts the following technical solutions: A hydraulic system for synchronous folding of a driving harrow includes a left luffing oil cylinder, a right luffing oil cylinder, and a two-way balance valve connecting the pump and the fuel tank through a multi-way valve. The two-way balance valve includes a first throttle valve and a second throttle valve. The first oil port of any one throttle valve is connected to the throttle hydraulic control port of the other throttle valve. Check valves are connected in parallel between the first oil port and the second oil port of the two throttle valves. The check valve conducts from the first oil port of the corresponding throttle valve to the second oil port of the corresponding throttle valve. The first oil port of the first throttle valve is connected to the outlet of the pump through a check valve when the multi-way valve is in the left position. The second oil port of the first throttle valve is respectively connected to the rodless chambers of the left luffing oil cylinder and the right luffing oil cylinder. The first oil port of the second throttle valve is connected to the fuel tank when the multi-way valve is in the left position. The second oil port of the second throttle valve is respectively connected to the rod chambers of the left luffing oil cylinder and the right luffing oil cylinder. The first oil port of the first throttle valve is connected to the fuel tank when the multi-way valve is in the right position. The first oil port of the second throttle valve is connected to the outlet of the pump through a check valve when the multi-way valve is in the right position. The multi-way valve in the neutral position closes the first oil ports of the first throttle valve and the second throttle valve. The second oil port of the first throttle valve is connected to the rodless chambers of the left luffing oil cylinder and the right luffing oil cylinder through a flow dividing and collecting valve.

[0014] An overflow valve serving as a safety valve is provided at the outlet of the pump.

[0015] By applying the two-way balance valve, the present utility model solves the problem of unstable descent during the folding and unfolding of the driving harrow, avoids jitter and noise, improves the operation comfort and the service life of the machine. By applying the flow dividing and flow collecting valve, the driving harrow is forced to be synchronized during the folding and unfolding process, avoiding the out-of-synchronization problem caused by different loads on both sides in the market. At the same time, the working efficiency is improved, and the operation is more comfortable and safe. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] In order to more clearly illustrate the technical solutions of the embodiments of the present utility model, the following will briefly introduce the drawings required to be used in the embodiments:

[0017] Figure 1 FIG. is a hydraulic system diagram of an existing synchronized folding driving harrow;

[0018] Figure 2 FIG. is another hydraulic system diagram of an existing synchronized folding driving harrow;

[0019] Figure 3 FIG. is the hydraulic system diagram of the present utility model;

[0020] Figure 4 For Figure 3 the structural diagram of the two-way balance valve in DETAILED DESCRIPTION OF THE EMBODIMENTS

[0021] In order to make the technical objectives, technical solutions and beneficial effects of the present utility model clearer, the following further explains the technical solutions of the present utility model in conjunction with the drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model, that is, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Usually, the components of the embodiments of the present utility model described and shown in the drawings here can be arranged and designed in various different configurations.

[0022] Specific embodiments of the hydraulic system for synchronized folding of the driving harrow involved in the present utility model, in Figure 3 and Figure 4Among them, the two-way balance valve 1 has two throttle valves, one is the first throttle valve 2 and the other is the second throttle valve 3. Both the first throttle valve 2 and the second throttle valve 3 are hydraulically controlled throttle valves. The first throttle valve 2 and the second throttle valve 3 respectively have a first oil port and a second oil port. The first oil port of the first throttle valve 2 is connected to the throttle hydraulic control port of the second throttle valve 3 to provide hydraulic control pressure for the second throttle valve 3 so as to adjust the opening size of the second throttle valve 3. The first oil port of the second throttle valve 3 is connected to the throttle hydraulic control port of the first throttle valve 2 to provide hydraulic control pressure for the first throttle valve 2 so as to adjust the opening size of the first throttle valve 2. Check valves 4 are connected in parallel between the first oil port and the second oil port of the two throttle valves. The check valve 4 conducts in the direction from the first oil port of the corresponding throttle valve to the second oil port of the corresponding throttle valve. That is to say, in the conducting direction of the check valve 4, the oil fluid can directly flow from the first oil port of the throttle valve to the second oil port without passing through the throttle valve.

[0023] When the multi-way valve 5 is in the left position, the first oil port of the first throttle valve 2 is connected to the outlet of the pump 6 through a check valve, and the first oil port of the second throttle valve 3 is connected to the fuel tank. When the multi-way valve 5 is in the right position, the first oil port of the first throttle valve 2 is connected to the fuel tank, and the first oil port of the second throttle valve 3 is connected to the outlet of the pump through a check valve. The second oil port of the first throttle valve 2 is divided into two paths, which are respectively connected to the rodless chambers of the left luffing cylinder 7 and the right luffing cylinder 8. The second oil port of the second throttle valve 3 is also divided into two paths, which are respectively connected to the rod chambers of the left luffing cylinder 7 and the right luffing cylinder 8. The neutral position of the multi-way valve 5 closes the first oil ports of the first throttle valve 2 and the second throttle valve 3.

[0024] The second oil port of the first throttle valve 2 is divided into two paths after passing through the flow dividing and collecting valve 9, which are respectively connected to the rodless chambers of the left luffing cylinder 7 and the right luffing cylinder 8.

[0025] An overflow valve 10 acting as a safety valve is provided at the outlet of the pump 6, which is a conventional setting.

[0026] The multi-way valve in this embodiment has a total of six oil ports. The first oil port is directly connected to the pump, the second oil port is connected to the pump through a check valve that allows the oil from the pump to pass through, the third oil port is connected to the fuel tank, the fourth oil port is connected to the first oil port of the first throttle valve, the fifth oil port is connected to the first oil port of the second throttle valve, and the sixth oil port is vacant. When the multi-way valve is in the left position, the first oil port is closed, the second oil port is connected to the fourth oil port, the third oil port is connected to the fifth oil port, and the sixth oil port is closed. When in the right position, the first oil port is closed, the second oil port is connected to the fifth oil port, the third oil port is connected to the fourth oil port, and the sixth oil port is closed. When in the middle position, the first oil port is connected to the sixth oil port, the second oil port is closed, the third oil port is closed, the fourth oil port is closed, and the fifth oil port is closed. Only one path is shown in this embodiment. In actual use, there can be multiple oil circuits. The sixth oil port is connected to other oil circuits. In this embodiment, the sixth oil port is vacant and the other oil circuits are not shown. Of course, the other oil circuits can also be provided with a pump and a directional control valve separately.

[0027] In this embodiment, the multi-way valve here functions as a three-position four-way directional control valve. In other embodiments, a three-position four-way directional control valve can also be directly used. When in the middle position, the oil ports connected to the two throttle valves are closed.

[0028] The specific working principle of the system is as follows: When the left path of the directional control valve is working, the oil from the pump enters the V2 port, that is, the first oil port of the first throttle valve, through the left check valve inside, and then passes through the flow dividing valve and flow collecting valve (acting as a flow dividing valve at this time) to reach the C2 and C3 ports, that is, it is divided into two paths, and finally flows into the rodless cavities of the left luffing cylinder 7 and the right luffing cylinder 8 respectively. The piston rods of the cylinders extend to achieve the synchronous and stable folding function. The oil flowing back from the rod cavities converges and passes through the C1 port, that is, the second oil port of the second throttle valve. At this time, the throttle orifice has been opened by the control pressure opposite to the first oil port of the first throttle valve. The oil in the C1 port passes through the throttle orifice to V1, that is, the first oil port of the second throttle valve, and then returns to the fuel tank from the multi-way valve.

[0029] When the right path of the directional control valve is working, the oil from the pump enters the V1 port, that is, the first oil port of the second throttle valve, passes through the right check valve inside, reaches the C1 port, the second oil port of the second throttle valve, and then enters the rod cavities of the left luffing cylinder 7 and the right luffing cylinder 8. The piston rods of the cylinders retract to achieve the synchronous and stable unfolding function. The oil in the rodless cavities of the left luffing cylinder 7 and the right luffing cylinder 8 respectively enter the C2 and C3 ports, and then pass through the flow dividing valve and flow collecting valve (acting as a flow collecting valve at this time). At this time, the throttle orifice has been opened by the control pressure at the first oil port of the second throttle valve, and flows out from the V2 port, that is, flows out from the first oil port of the first throttle valve, and finally returns to the fuel tank from the multi-way valve.

[0030] When the directional control valve is in the neutral position, there is no control pressure at the throttling hydraulic control ports of the two throttle valves. The one-way valves and the two throttle valves lock the oil passage, keeping the oil cylinder stationary.

[0031] Finally, it should be noted that the above embodiments are only used to illustrate rather than limit the technical solutions of the present invention. Any equivalent replacement of the present invention and any modification or partial replacement that does not depart from the spirit and scope of the present invention shall be covered by the scope of protection of the claims of the present invention.

Claims

1. A hydraulic system for driving a rake to fold synchronously, comprising a left luffing oil cylinder and a right luffing oil cylinder and a two-way balancing valve connected to a pump and an oil tank through a multi-way valve, wherein the two-way balancing valve comprises a first throttle valve and a second throttle valve, wherein a first oil port of any throttle valve is connected to a throttle hydraulic control port of another throttle valve, and a check valve is connected in parallel between the first oil port and the second oil port of the two throttle valves, wherein the check valve is connected from the first oil port of the corresponding throttle valve to the second oil port of the corresponding throttle valve, and when the first oil port of the first throttle valve is in the left position of the multi-way valve, the check valve is connected to the pump through the check valve. The outlet of the first throttle valve is connected, the second oil port of the first throttle valve is connected to the rodless chamber of the left and right luffing cylinders respectively, the first oil port of the second throttle valve is connected to the oil tank when the multi-way valve is in the left position, the second oil port of the second throttle valve is connected to the rod chamber of the left and right luffing cylinders respectively, the first oil port of the first throttle valve is connected to the oil tank when the multi-way valve is in the right position, the first oil port of the second throttle valve is connected to the outlet of the pump through a one-way valve when the multi-way valve is in the right position, the first oil port of the first throttle valve and the second throttle valve is closed in the middle position of the multi-way valve, characterized in that: The second oil port of the first throttle valve is connected to the rodless chambers of the left and right luffing cylinders through the flow dividing and collecting valves.

2. The hydraulic system for driving the synchronous folding of the rake according to claim 1, characterized in that: An overflow valve serving as a safety valve is arranged at the outlet of the pump.

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