Fan positive and negative rotation control oil way and excavator

Abstract

The invention relates to a fan forward and reverse rotation control oil way and an excavator, and belongs to the technical field of fan forward and reverse rotation control. Comprising a heat dissipation pump, a reverse rotation control valve, a fan motor, a fan, a radiator and an oil tank, the heat dissipation pump is connected with the reverse rotation control valve, and a port A and a port B of the reverse rotation control valve are connected with a forward rotation oil port and a reverse rotation oil port respectively; the reverse rotation control valve comprises a forward and reverse rotation reversing electromagnetic valve, a back pressure control valve and a one-way valve; the reverse rotation control valve is connected with an oil inlet of the forward and reverse reversing electromagnetic valve through a first oil way, and a first working oil port and a second working oil port of the forward and reverse reversing electromagnetic valve are connected with a port A and a port B of the reverse rotation control valve respectively. An oil return opening of the forward and reverse reversing electromagnetic valve is connected with a T opening of the reverse control valve through a second oil way, and the back pressure control valve is arranged on the second oil way. In the reverse rotation switching process of the fan, the oil supplementing effect can be improved by increasing the oil return back pressure, and meanwhile rapid and safe speed reduction of the motor is achieved.

Description

Technical Field

[0001] The invention relates to a fan forward and reverse rotation control oil circuit and an excavator, belonging to the technical field of fan forward and reverse rotation control. Background Art

[0002] At present, most excavators use an independent cooling system with a hydraulic motor driving the fan, which can not only realize the on-demand control of the fan speed, but also realize the fan reversal, remove the dust and lint blocking the radiator surface, and improve the heat dissipation effect of the radiator. How to quickly and safely realize the fan reversal switching, how to prevent users from operating the fan reversal beyond the allowable temperature of the machine, how to avoid electrical failures that cause the cooling system to not work properly and increase power consumption losses, and ensure the reliability and energy saving of the cooling system are technical problems that need to be solved urgently in the existing technology. Summary of the invention

[0003] The purpose of the present invention is to provide a fan forward and reverse control oil circuit and an excavator. When the fan is switched between forward and reverse directions, the back pressure of the return oil circuit is increased by a back pressure control valve, and the flow of the fan motor oil return port (second oil circuit) is replenished to the fan motor oil inlet side (first oil circuit) through a one-way valve, so as to avoid air suction caused by insufficient oil supply to the motor oil inlet due to a sudden decrease in the output flow of the cooling pump. By increasing the oil replenishment effect, the purpose of quickly and safely slowing down the motor can be achieved.

[0004] In order to achieve the above object, the present invention adopts the following technical solutions to achieve: In the first aspect, the present invention provides a fan forward and reverse control oil circuit, which includes: a heat dissipation pump, a reverse control valve, a fan motor, a fan, a radiator and an oil tank, wherein the oil outlet of the heat dissipation pump is connected to the P port of the reverse control valve, and the A port and the B port of the reverse control valve are respectively connected to the forward oil port and the reverse oil port of the fan motor; the T port of the reverse control valve is connected to the oil tank through the radiator; the reverse control valve includes a forward and reverse switching solenoid valve, a back pressure control valve and a one-way valve; the P port of the reverse control valve is connected to the oil inlet of the forward and reverse switching solenoid valve through the first oil circuit, and the forward The first working oil port and the second working oil port of the reverse switching solenoid valve are respectively connected to the A port and the B port of the reverse control valve; by switching the valve core position of the forward and reverse switching solenoid valve, the oil inlet of the forward and reverse switching solenoid valve can be connected to the first working oil port or the second working oil port; the oil return port of the forward and reverse switching solenoid valve is connected to the T port of the reverse control valve through the second oil circuit, the back pressure control valve is arranged on the second oil circuit, the oil inlet side of the one-way valve is connected to the second oil circuit upstream of the back pressure control valve, and the oil outlet side of the one-way valve is connected to the first oil circuit.

[0005] Optionally, the forward and reverse conversion solenoid valve includes a forward position, a middle position and a reverse position; when the forward and reverse conversion solenoid valve is in the forward position, the oil inlet of the forward and reverse conversion solenoid valve is connected to the first working oil port, and the second working oil port of the forward and reverse conversion solenoid valve is connected to the oil return port; when the forward and reverse conversion solenoid valve is in the middle position, the oil inlet of the forward and reverse conversion solenoid valve is connected to the oil return port; when the forward and reverse conversion solenoid valve is in the reverse position, the oil inlet of the forward and reverse conversion solenoid valve is connected to the second working oil port, and the first working oil port of the forward and reverse conversion solenoid valve is connected to the oil return port.

[0006] Optionally, the lower end and upper end of the forward-reverse conversion solenoid valve are respectively connected to a forward solenoid valve and a reverse solenoid valve. When the forward solenoid valve is energized, the forward-reverse conversion solenoid valve is in a forward position. When the reverse solenoid valve is energized, the forward-reverse conversion solenoid valve is in a reverse position. When both the forward solenoid valve and the reverse solenoid valve are not energized, the forward-reverse conversion solenoid valve is in a neutral position.

[0007] Optionally, the lower end and upper end of the forward-reverse conversion solenoid valve are respectively connected to a forward knob and a reverse knob. When the forward knob is rotated into place, the forward-reverse conversion solenoid valve is in a forward position. When the reverse knob is rotated into place, the forward-reverse conversion solenoid valve is in a reverse position.

[0008] Optionally, the back-pressure control valve includes a back-pressure position and an original position; after the back-pressure control valve is switched from the original position to the back-pressure position, the return oil back pressure on the second oil circuit increases.

[0009] Optionally, the back pressure control valve is a solenoid valve.

[0010] Optionally, the back pressure control valve switches from an original position to a back pressure position when energized.

[0011] Optionally, it also includes: A relief valve, wherein the oil inlet of the relief valve is connected to the first oil circuit, and the oil outlet of the relief valve is connected to the second oil circuit downstream of the back pressure control valve.

[0012] Optionally, a first pressure sensor and a second pressure sensor are respectively provided at port A and port B of the reversing control valve.

[0013] In a second aspect, the present invention provides an excavator, which includes the fan forward and reverse rotation control oil circuit.

[0014] Compared with the prior art, the present invention has the following beneficial effects: The present invention can increase the oil replenishment effect by increasing the oil return back pressure during the fan reverse switching process, and at the same time realize the rapid and safe deceleration of the motor; when the forward and reverse switching solenoid valve control wiring harness has an electrical fault, the fan can still work forward or reverse through manual reversing, providing better working guarantee for the machine. When the proportional valve control wiring harness of the heat dissipation pump has an electrical fault and heat dissipation is not required, the heat dissipation pump outputs the maximum flow oil directly to the return oil circuit through the mid-position H function PT oil circuit, with small power loss and avoiding increased fuel consumption. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 This is a schematic diagram of the structure of the fan forward and reverse rotation control oil circuit in Example 1.

[0016] Numbers in the figure: 1, cooling pump; 2, reverse control valve; 21, overflow valve; 22, back pressure control valve; 23, forward and reverse switching solenoid valve; 3, fan motor; 4, fan; 5, radiator; 6, fuel tank; 7, second pressure sensor; 8, first pressure sensor. DETAILED DESCRIPTION

[0017] In the description of the present invention, it should be understood that the terms "center", "longitudinal", "lateral", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like indicate positions or positional relationships based on the positions or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and the like are only used for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of technical features indicated. Thus, features defined as "first", "second", and the like may explicitly or implicitly include one or more of the features. In the description of the present invention, unless otherwise specified, "multiple" means two or more. In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood by specific circumstances.

[0018] The present invention will be further described below in conjunction with the accompanying drawings. The following embodiments are only used to more clearly illustrate the technical solution of the present invention, and cannot be used to limit the protection scope of the present invention. Example 1

[0019] Combination Figure 1 The present embodiment provides a fan forward and reverse control oil circuit, which includes: a heat dissipation pump 1, a reverse control valve 2, a fan motor 3, a fan 4, a radiator 5 and a hydraulic oil tank 6.

[0020] The oil outlet of the heat dissipation pump 1 is connected to the P port of the reversing control valve 2, and the A port and the B port of the reversing control valve 2 are respectively connected to the forward oil port and the reverse oil port of the fan motor 3; the T port of the reversing control valve 2 is connected to the oil tank 6 through the radiator 5; the reversing control valve 2 includes a forward and reverse switching solenoid valve 23, a back pressure control valve 22 and a one-way valve; the P port of the reversing control valve 2 is connected to the oil inlet of the forward and reverse switching solenoid valve 23 through the first oil circuit, and the first working oil port and the second working oil port of the forward and reverse switching solenoid valve 23 are respectively Connect the A port and the B port of the reversing control valve 2; by switching the valve core position of the forward and reverse switching solenoid valve 23, the oil inlet of the forward and reverse switching solenoid valve 23 can be connected to the first working oil port or the second working oil port; the oil return port of the forward and reverse switching solenoid valve 23 is connected to the T port of the reversing control valve 2 through the second oil circuit, the back pressure control valve 22 is arranged on the second oil circuit, the oil inlet side of the one-way valve is connected to the second oil circuit upstream of the back pressure control valve 22, and the oil outlet side of the one-way valve is connected to the first oil circuit.

[0021] The forward and reverse switching solenoid valve 23 includes a forward rotation position, a neutral position and a reverse rotation position.

[0022] When the forward / reverse switching solenoid valve 23 is in the forward rotation position, the oil inlet of the forward / reverse switching solenoid valve 23 is connected to the first working oil port, and the second working oil port of the forward / reverse switching solenoid valve 23 is connected to the oil return port.

[0023] When the forward and reverse switching solenoid valve 23 is in the middle position, the forward and reverse switching solenoid valve 23 forms an H function, and the oil inlet is connected to the oil return port. Specifically, when the cooling pump 1 operates at the maximum displacement due to an electrical fault, the output flow of the cooling pump 1 directly returns the oil through the middle PT oil circuit of the reversing valve, and the fan 4 is not driven to rotate and no power loss is generated.

[0024] When the forward and reverse switching solenoid valve 23 is in the reverse position, the oil inlet of the forward and reverse switching solenoid valve 23 is connected to the second working oil port, and the first working oil port of the forward and reverse switching solenoid valve 23 is connected to the oil return port.

[0025] In a specific embodiment, the valve core position switching of the forward and reverse switching solenoid valve 23 is controlled by the solenoid valve, and the lower end and upper end of the forward and reverse switching solenoid valve 23 are respectively connected to the forward solenoid valve and the reverse solenoid valve. When the forward solenoid valve is energized, the forward and reverse switching solenoid valve 23 is in the forward rotation position; when the reverse solenoid valve is energized, the forward and reverse switching solenoid valve 23 is in the reverse position; when both the forward solenoid valve and the reverse solenoid valve are not energized, the forward and reverse switching solenoid valve 23 is in the middle position.

[0026] The back pressure control valve 22 includes a back pressure position and an original position. After the back pressure control valve 22 is switched from the original position to the back pressure position, the return oil back pressure on the second oil circuit increases. The back pressure control valve 22 is a solenoid valve with a return spring connected to the lower end. When the back pressure control valve 22 is energized, the back pressure control valve 22 is switched from the original position to the back pressure position.

[0027] In this embodiment, when switching the rotation direction of the fan 4, the forward rotation switching to the reverse rotation is taken as an example. When the fan 4 needs to be switched from forward rotation to reverse rotation, the reverse switch is operated by the instrument, and the controller keeps the forward rotation solenoid valve Y1 in the energized state, and the forward and reverse switching solenoid valve 23 is in the forward rotation position. The controller controls the heat pump 1 to the maximum current, so that the heat pump 1 outputs the minimum flow. At the same time, the controller controls the back pressure control valve 22 to be energized and reversed, and the back pressure of the return oil circuit increases. The flow of the return oil port of the fan motor 4 (the second oil circuit) is supplemented with oil to the oil inlet side (the first oil circuit) of the fan motor 4 through the one-way valve, so as to avoid air suction caused by insufficient oil supply at the motor oil inlet due to a sudden decrease in the output flow of the heat pump 1.

[0028] In addition, the first pressure sensor 8 and the second pressure sensor 7 are respectively provided at the A port and the B port of the reversing control valve 2. The back pressure value can be adjusted according to the demand by detecting the pressure value of the second pressure sensor 7 on the oil return side, and the rotation speed of the fan motor 3 can be reduced quickly under the premise that the pressure value on the oil return side does not exceed the set maximum safety value. When it is detected that the pressure value of the second pressure sensor 7 on the oil return side of the motor is reduced to the set minimum safety value, the controller controls the forward solenoid valve Y1 to lose power, controls the reverse solenoid valve Y2 to be energized, and the forward and reverse conversion solenoid valve 23 is switched from the middle position to the reverse position, and at the same time controls the back pressure control valve 22 to lose power to cancel the back pressure. During the middle position process, the oil on the oil return side of the motor continues to replenish oil to the oil inlet side of the motor through the middle position H function of the forward and reverse conversion solenoid valve 23 (the oil inlet and the oil return port are connected) under the action of residual pressure, thereby reducing the risk of motor air absorption. After the forward and reverse conversion solenoid valve 23 is switched to the reverse position, the controller simultaneously controls the heat dissipation pump 1 to increase the output flow rate to achieve back-blowing of the fan 4. After the back-blowing is finished, the fan 4 is controlled to switch to forward rotation according to the above switching method.

[0029] Based on the forward and reverse oil circuit of the fan 4 and the above method, this embodiment can increase the oil replenishment effect by increasing the return oil back pressure during the reverse switching process of the fan 4, and at the same time achieve rapid and safe deceleration of the motor.

[0030] In a specific embodiment, the lower end and the upper end of the forward-reverse switching solenoid valve 23 are respectively connected to a forward knob and a reverse knob. The forward knob and the reverse knob can be rotated manually, so that when an electrical fault occurs and the forward solenoid valve and the reverse solenoid valve of the forward-reverse switching solenoid valve 23 cannot be electrically switched, the H1 knob, i.e., the forward knob, can be manually operated to switch the forward-reverse switching solenoid valve 23 to the forward position, so that the forward oil circuit works, at this time PA and BT are connected, and the heat dissipation pump 1 outputs oil to drive the motor to rotate forward. Similarly, the H2 knob, i.e., the reverse knob, can be manually operated to switch the forward-reverse switching solenoid valve 23 to the reverse position, and the reverse oil circuit works, at this time PB and AT are connected, and the heat dissipation pump 1 outputs oil to drive the motor to rotate in the reverse direction, so as to improve the working reliability of the forward and reverse control oil circuit of the fan 4.

[0031] The heat pump 1 is a variable displacement pump, and the maximum pressure of the heat pump 1 is controlled by the relief valve 21. When the actual load pressure does not reach the set pressure of the relief valve 21, the heat pump 1 works at the maximum displacement. When the current value of the proportional valve is 0, the relief pressure set by the relief valve 21 of the heat pump 1 is the maximum. The larger the control current of the heat pump 1, the smaller the relief pressure set by the relief valve 21 of the heat pump 1. The oil inlet of the relief valve 21 is connected to the first oil circuit, and the oil outlet of the relief valve 21 is connected to the second oil circuit downstream of the back pressure control valve 22.

[0032] In addition, the oil temperature and water temperature can be monitored by sensors. When the maximum oil temperature and water temperature exceed the set limit, the use of fan 4 reverse rotation is limited through a pre-arranged program to prevent the oil temperature and water temperature from continuing to rise during the reversal process, causing system damage. Example 2

[0033] This embodiment provides an excavator, which includes the fan forward and reverse rotation control oil circuit described in Embodiment 1.

[0034] The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the technical principles of the present invention. These improvements and modifications should also be regarded as the scope of protection of the present invention.

Claims

1. A fan forward and reverse control oil circuit, characterized in that: include: A heat dissipation pump (1), a reversing control valve (2), a fan motor (3), a fan (4), a radiator (5) and an oil tank (6), wherein the oil outlet of the heat dissipation pump (1) is connected to the P port of the reversing control valve (2), and the A port and the B port of the reversing control valve (2) are respectively connected to the forward oil port and the reverse oil port of the fan motor (3); the fan motor (3) is used to drive the fan (4) to rotate forward or reverse; the T port of the reversing control valve (2) is connected to the oil tank (6) through the radiator (5); the reversing control valve (2) comprises a forward-reversing switching solenoid valve (23), a back pressure control valve (22) and a one-way The reverse control valve (2) is connected to the oil inlet of the forward and reverse switching solenoid valve (23) through a first oil circuit, and the first working oil port and the second working oil port of the forward and reverse switching solenoid valve (23) are respectively connected to the A port and the B port of the reverse control valve (2); the oil return port of the forward and reverse switching solenoid valve (23) is connected to the T port of the reverse control valve (2) through a second oil circuit, and the back pressure control valve (22) is arranged on the second oil circuit; the oil inlet side of the one-way valve is connected to the second oil circuit upstream of the back pressure control valve (22), and the oil outlet side of the one-way valve is connected to the first oil circuit.

2. The fan forward and reverse rotation control oil circuit according to claim 1, characterized in that: The forward and reverse switching solenoid valve (23) comprises a forward rotation position, a middle position and a reverse rotation position; when the forward and reverse switching solenoid valve (23) is in the forward rotation position, the oil inlet of the forward and reverse switching solenoid valve (23) is connected to the first working oil port, and the second working oil port of the forward and reverse switching solenoid valve (23) is connected to the oil return port; when the forward and reverse switching solenoid valve (23) is in the middle position, the oil inlet of the forward and reverse switching solenoid valve (23) is connected to the oil return port; when the forward and reverse switching solenoid valve (23) is in the reverse rotation position, the oil inlet of the forward and reverse switching solenoid valve (23) is connected to the second working oil port, and the first working oil port of the forward and reverse switching solenoid valve (23) is connected to the oil return port.

3. The fan forward and reverse rotation control oil circuit according to claim 2, characterized in that: The lower end and upper end of the forward-reverse switching solenoid valve (23) are respectively connected to a forward solenoid valve and a reverse solenoid valve; when the forward solenoid valve is energized, the forward-reverse switching solenoid valve (23) is in a forward rotation position; when the reverse solenoid valve is energized, the forward-reverse switching solenoid valve (23) is in a reverse rotation position; when both the forward solenoid valve and the reverse solenoid valve are not energized, the forward-reverse switching solenoid valve (23) is in a neutral position.

4. The fan forward and reverse rotation control oil circuit according to claim 2, characterized in that: The lower end and upper end of the forward-reverse switching solenoid valve (23) are respectively connected to a forward knob and a reverse knob; when the forward knob is rotated to a certain position, the forward-reverse switching solenoid valve (23) is in a forward rotation position; and when the reverse knob is rotated to a certain position, the forward-reverse switching solenoid valve (23) is in a reverse rotation position.

5. The fan forward and reverse rotation control oil circuit according to claim 1, characterized in that: The back pressure control valve (22) comprises a back pressure position and an original position; after the back pressure control valve (22) is switched from the original position to the back pressure position, the return oil back pressure on the second oil circuit increases.

6. The fan forward and reverse rotation control oil circuit according to claim 5, characterized in that: The back pressure control valve (22) is a solenoid valve.

7. The fan forward and reverse rotation control oil circuit according to claim 6, characterized in that: The back pressure control valve (22) switches from the original position to the back pressure position when energized.

8. The fan forward and reverse rotation control oil circuit according to claim 6, characterized in that: Also includes: A relief valve (21), wherein an oil inlet of the relief valve (21) is connected to the first oil circuit, and an oil outlet of the relief valve (21) is connected to a second oil circuit downstream of the back pressure control valve (22).

9. The fan forward and reverse rotation control oil circuit according to claim 1, characterized in that: A first pressure sensor (8) and a second pressure sensor (7) are respectively provided at the A port and the B port of the reversing control valve (2).

10. An excavator, characterized in that: It comprises the fan forward and reverse rotation control oil circuit as described in any one of claims 1 to 9.

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