CN110056549B - Automatic control lifting hydraulic cylinder potential energy recovery system and method - Google Patents

Abstract

The invention discloses an automatically controlled lifting hydraulic cylinder potential energy recovery system and method, comprising a variable pump, a relief valve, a three-position four-way reversing valve, a lifting hydraulic cylinder and other components. The upper chamber of the hydraulic cylinder and the lower chamber of the hydraulic cylinder are respectively connected to the first two-position three-way reversing valve and the three-position four-way reversing valve, the first two-position three-way reversing valve is connected to the oil tank and the variable motor, and the variable motor is connected to the water pump. The input end of the water pump is connected to the low-level water tank, the output end is connected to the second two-position three-way reversing valve, the second two-position three-way reversing valve is connected to the high-level water tank and the cooler, the temperature sensor is connected to the fuel tank, and the liquid level sensor is connected to the high-level water tank. The devices are respectively connected with a temperature sensor, a liquid level sensor, a first two-position three-way reversing valve and a second two-position three-way reversing valve. The invention can recover the potential energy when the lifting hydraulic cylinder is lowered, and at the same time, the recovered potential energy can be converted into the potential energy of water, and can also be used for cooling the hydraulic system, thereby improving the energy utilization rate.

Description

An automatically controlled lifting hydraulic cylinder potential energy recovery system and method

technical field

The invention relates to the field of heavy machinery, in particular to an automatically controlled lifting hydraulic cylinder potential energy recovery system and method.

Background technique

Heavy machinery plays an important role in the production activities of the national economy. There is a large amount of gravitational potential energy in the lifting hydraulic cylinder in heavy machinery and the heavy objects it lifts. During the descending process of the hydraulic cylinder, a large amount of gravitational potential energy often passes through the hydraulic valve. The throttling effect is converted into heat energy and dissipated in vain, which increases the production cost of the enterprise and causes a huge waste of energy. If we recycle this part of the energy through some means, it will be of great significance for enterprises to reduce production costs and save energy and protect the environment.

The lifting hydraulic cylinder performs a regular reciprocating lifting movement, and the potential energy is recovered when it is lowered. Usually, the hydraulic motor is arranged in the oil return circuit to connect to the generator to generate electricity, and then sent to the battery for storage through the rectifier. However, the number of energy conversions in this process is large. , the energy recovery efficiency is low, and the cost of large-capacity power storage devices is high.

SUMMARY OF THE INVENTION

In view of the above situation, the present invention provides an automatically controlled lifting hydraulic cylinder potential energy recovery system, which overcomes the deficiencies of the prior art. For heat dissipation, most of the energy can also be converted into the potential energy of water, so as to be used in the production of industrial production lines and save costs.

The technical solution adopted in the present invention is to provide an automatically controlled lifting hydraulic cylinder potential energy recovery system, including a hydraulic oil tank, a variable pump, a relief valve, a three-position four-way reversing valve, a one-way valve, a lifting hydraulic cylinder, a first Two-position three-way reversing valve, speed control valve, variable motor, water pump, low-level water tank, cooler, second two-position three-way reversing valve, high-level water tank, liquid level sensor, temperature sensor, controller and motor, the described The first oil port of the variable pump is connected with the hydraulic oil in the hydraulic oil tank, the rotating shaft of the variable pump is connected with the electric motor, and the second oil port of the variable pump is connected with the three-position four-way reversing valve. The second oil port is connected, the relief valve is connected in parallel with the variable pump, and the control oil circuit of the relief valve is connected to the oil pipe between the variable pump and the three-position four-way reversing valve. The third oil port of the four-way reversing valve is connected to the first oil port of the one-way valve, the second oil port of the one-way valve is connected to the first oil port of the lifting hydraulic cylinder, and the one-way valve One-way conduction from the first oil port to the second oil port, the fourth oil port of the three-position four-way reversing valve is connected to the second oil port of the lifting hydraulic cylinder, and the three-position four-way reversing valve The first oil port of the valve is closed, and the piston rod of the lift hydraulic cylinder is connected to the load.

The first oil port of the variable motor is connected to the second oil port of the cooler, the first oil port of the cooler is communicated with the hydraulic oil in the hydraulic oil tank, and the second oil port of the variable motor is connected The first oil port of the first two-position three-way reversing valve, the second oil port of the speed control valve is connected to the second oil port of the first two-position three-way reversing valve, the speed control valve The first oil port of the first oil port is connected to the oil pipe between the variable motor and the cooler, and the third oil port of the first two-position three-way reversing valve is connected to the oil pipe between the one-way valve and the lifting hydraulic cylinder, The output shaft of the variable motor is connected to the rotating shaft of the water pump, the first interface of the water pump is connected to the low-level water tank, the second interface is connected to the third interface of the second two-position three-way reversing valve, and the cooling The first cooling water port of the device is connected with the cooling water of the low-level water tank, and the second cooling water port is connected with the second port of the second two-position three-way reversing valve, and the second two-position three-way reversing valve The first interface of the valve communicates with the cooling water of the high-level water tank; and the liquid level sensor detects the water level of the high-level water tank, and feeds back a detection signal to the controller, and the temperature sensor detects the hydraulic oil tank. The temperature of the hydraulic oil in the interior is measured, and the detection signal is fed back to the controller, and the first two-position three-way reversing valve and the second two-position three-way reversing valve communicate with the controller.

Preferably, the controller adopts a logic control unit PLC.

Preferably, when the lifting hydraulic cylinder rises, the three-position four-way reversing valve is in the left position.

Further, the first two-position three-way reversing valve and the second two-position three-way reversing valve are electromagnetic reversing valves.

Preferably, the variable displacement pump is a unidirectional variable displacement pump, and the variable displacement motor is a unidirectional variable displacement motor.

Preferably, all the pipelines through which the hydraulic oil passes are steel wire high-pressure pipes.

Preferably, the provided method for an automatically controlled lifting hydraulic cylinder potential energy recovery system includes the following steps:

S1: When the lifting hydraulic cylinder descends, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature exceeds the pre-set temperature upper limit, the controller controls the first two-position three-way reversing The valve is in the right position, and the second two-position three-way reversing valve is in the left position. At this time, the variable motor drives the water pump to work, and the water pump drives the water into the cooler to cool the oil, that is, the recovered energy is used to drive the water pump to Cooling the hydraulic system;

S2: When the lifting hydraulic cylinder is lowered, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor detects that the liquid level does not reach the pre-set temperature range When the upper limit of the liquid level is reached, the controller controls the first two-position three-way reversing valve to be in the right position, and the second two-position three-way reversing valve is in the right position. At this time, the variable motor drives the water pump to work, and the water is pumped into the high position. The water tank converts the potential energy recovered when the lifting hydraulic cylinder is lowered into the potential energy of water;

S3: When the lifting hydraulic cylinder is lowered, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor detects that the liquid level reaches the pre-set temperature range When the upper limit of the liquid level is reached, the controller controls the first two-position three-way reversing valve to be in the left position. At this time, the variable motor and water pump device do not work, and the potential energy of the lifting hydraulic cylinder cannot be recovered, and the oil flows back through the speed control valve. Hydraulic tank.

Compared with the prior art, the present invention has the following advantages:

1. The potential energy recovery system of the lifting hydraulic cylinder can realize the automatic switching between the normal mode and the energy-saving mode. In the energy-saving mode, the recovered potential energy can be converted into the potential energy of the water in the high-level water tank, which can be used as the water supply source in the factory area, and can also be used by the water pump. Water is used for hydraulic system cooling, realizing multi-purpose recovery of energy;

2. The recovered potential energy will be directly used for cooling the hydraulic system and supplying water to the plant area. Compared with the traditional variable motor-driven generator, the generator is connected to the rectifier, and finally the electrical energy is stored in the large-capacity battery, the number of intermediate conversions is less, High energy recovery efficiency;

3. The variable motor, high-level water tank, temperature sensor, liquid level sensor, controller and other components required by the system have low cost, strong environmental adaptability, and high reliability of the system;

4. During the descending process of the hydraulic cylinder, the detection control unit firstly judges whether the hydraulic system needs to be cooled, and then judges whether the high-level water tank needs to be filled with water. When the above two functions do not require water source, the system will automatically switch to the normal mode, reducing the need for manual work. the process of intervention.

Description of drawings

1 is a schematic diagram of an automatically controlled lifting hydraulic cylinder potential energy recovery system of the present invention; and

FIG. 2 is a flow chart of the control strategy of the present invention.

The main reference signs of the present invention are as follows:

1. Hydraulic tank; 2. Variable pump; 3. Relief valve; 4. Three-position four-way reversing valve; 5. One-way valve; 6. Lifting hydraulic cylinder; 7. Load; 8. First two-position three-way Reversing valve; 9. Speed regulating valve; 10. Variable motor; 11. Water pump; 12. Low water tank; 13. Cooler; 14. Second two-position three-way reversing valve; 15. High water tank; 16. Liquid level sensor; 17, temperature sensor; 18, controller; 19, motor.

Detailed ways

In order to detail the technical content, structural features, achieved objects and effects of the present invention, the following will be described in detail with reference to the accompanying drawings.

The present invention provides an automatically controlled lifting hydraulic cylinder potential energy recovery system, as shown in FIG. 1 , including a hydraulic oil tank 1, a variable pump 2, a relief valve 3, a three-position four-way reversing valve 4, a one-way valve 5, a lift Hydraulic cylinder 6, first two-position three-way reversing valve 8, speed regulating valve 9, variable motor 10, water pump 11, low-level water tank 12, cooler 13, second two-position three-way reversing valve 14, high-level water tank 15, The liquid level sensor 16, the temperature sensor 17, the controller 18 and the motor 19, the first oil port of the variable pump 2 is connected with the hydraulic oil in the hydraulic oil tank 1, the rotating shaft of the variable pump 2 is connected with the motor 19, the second The oil port is connected to the second oil port of the three-position four-way reversing valve 4, the relief valve 3 is connected in parallel with the variable pump 2, and the control oil circuit of the relief valve 3 connects the variable pump 2 and the three-position four-way reversing valve 4 The third oil port of the three-position four-way reversing valve 4 is connected to the first oil port of the check valve 5, and the second oil port of the check valve 5 is connected to the first oil port of the lifting hydraulic cylinder 6, and The one-way valve 5 is unidirectionally connected from its first oil port to the second oil port, and the fourth oil port of the three-position four-way reversing valve 4 is connected to the second oil port of the lifting hydraulic cylinder 6, and the three-position four-way reversing The first oil port of the valve 4 is closed, and the piston rod of the lifting hydraulic cylinder 6 is connected to the load 7 .

The first oil port of the variable motor 10 is connected to the second oil port of the cooler 13, the first oil port of the cooler 13 is communicated with the hydraulic oil in the hydraulic oil tank 1, and the second oil port of the variable motor 10 is connected to the first two-position three The first oil port of the reversing valve 8, the second oil port of the speed control valve 9 is connected to the second oil port of the first two-position three-way reversing valve 8, and the first oil port of the speed control valve 9 is connected to the variable motor 10. It is connected to the oil pipe between the cooler 13, the third oil port of the first two-position three-way reversing valve 8 is connected to the oil pipe between the check valve 5 and the lifting hydraulic cylinder 6, and the output shaft of the variable motor 10 is connected to the water pump 11. The rotating shaft, the first interface of the water pump 11 is connected to the low-level water tank 12, the second interface is connected to the third interface of the second two-position three-way reversing valve 14, the first cooling water interface of the cooler 13 is communicated with the cooling water of the low-level water tank 12, The second cooling water port is connected to the second port of the second two-position three-way reversing valve 14, and the first port of the second two-position three-way reversing valve 14 is communicated with the cooling water of the high-level water tank 15; and the liquid level sensor 16 Detect the water level of the high-level water tank 15, and feed back the detection signal to the controller 18. The temperature sensor 17 detects the temperature of the hydraulic oil in the hydraulic oil tank 1, and feeds the detection signal back to the controller 18. The first two-position three-way reversing valve 8 and the second 3/2 directional valve 14 are both in communication with the controller 18 .

The controller 18 adopts a logic control unit PLC; when the lifting hydraulic cylinder 6 rises, the three-position four-way reversing valve 4 is in the left position; the first two-position three-way reversing valve 8 and the second two-position three-way reversing valve 14 are both The electromagnetic reversing valve is used; the variable pump 2 is a one-way variable pump, and the variable motor 10 is a one-way variable motor; the pipelines through which the hydraulic oil passes are made of steel wire high-pressure pipes.

As shown in Figure 1 and Figure 2, the method for automatically controlling the potential energy recovery system of the lifting hydraulic cylinder includes the following steps:

S1: When the lifting hydraulic cylinder 6 is lowered, the three-position four-way reversing valve 4 is in the right position. When the temperature sensor 17 detects that the oil temperature exceeds the temperature upper limit set in advance, the controller 18 controls the first and second positions The three-way reversing valve 8 is in the right position, and the second two-position three-way reversing valve 14 is in the left position. At this time, the variable motor 10 drives the water pump 11 to work. Cooling, that is, using the recovered energy to drive the water pump 11 to cool the hydraulic system;

S2: When the lifting hydraulic cylinder 6 is lowered, the three-position four-way reversing valve 4 is in the right position. When the temperature sensor 17 detects that the oil temperature is within the temperature range set in advance, and the liquid level sensor 16 detects that the liquid level is not When the upper limit of the liquid level set in advance is reached, the controller 18 controls the first two-position three-way reversing valve 8 to be in the right position, and the second two-position three-way reversing valve 14 is in the right position. At this time, the variable motor 10 drives the When the water pump 11 works, the water is pumped into the high-level water tank 15, and the potential energy recovered when the lifting hydraulic cylinder 6 is lowered is converted into the potential energy of water;

S3: When the lifting hydraulic cylinder 6 descends, the three-position four-way reversing valve 4 is in the right position. When the temperature sensor 17 detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor 16 detects that the liquid level reaches When the upper limit of the liquid level is set in advance, the controller 18 controls the first two-position three-way reversing valve 8 to be in the left position. At this time, the variable motor 10 and the water pump 11 do not work, and the potential energy of the lifting hydraulic cylinder 6 cannot be recovered. , the oil flows back to the hydraulic oil tank 1 through the speed regulating valve 9 .

The optional concrete implementation process of the present invention is as follows:

Connect the oil inlet of the variable pump 2 with the hydraulic oil pipe in the hydraulic oil tank 1, this part of the operation can be carried out last, and then connect the rotating shaft of the variable pump 2 and the motor 19 with a coupling, the output of the variable pump 2. The oil port is connected to the second oil port of the three-position four-way reversing valve 4, the relief valve 3 is connected in parallel with the variable pump 2, and the control oil circuit of the relief valve 3 connects the variable pump 2 and the three-position four-way reversing The oil pipe between the valves 4, the third oil port of the three-position four-way reversing valve 4 is connected to the first oil port of the check valve 5, and the second oil port of the check valve 5 is connected to the rodless cavity oil of the lifting hydraulic cylinder 6 and the one-way valve 5 leads from the first oil port to the second oil port of the one-way valve 5 in a one-way direction, and the fourth oil port of the three-position four-way reversing valve 4 is connected to the rod cavity oil port of the lifting hydraulic cylinder 6 , and the first oil port of the three-position four-way reversing valve 4 is closed, and the piston rod of the lifting hydraulic cylinder 6 is connected to the load 7 .

The oil outlet of the variable motor 10 is connected to the second oil port of the cooler 13, the first oil port of the cooler 13 is communicated with the hydraulic oil in the hydraulic oil tank 1, and the oil inlet of the variable motor 10 is connected to the first two-position three-way exchange The first oil port of the direction valve 8, one oil port of the speed control valve 9 is connected to the second oil port of the first two-position three-way reversing valve 8, and the other oil port of the speed control valve 9 is connected to the variable motor 10 and the cooler. The oil pipes between 13 are connected, the third oil port of the first two-position three-way reversing valve 8 is connected to the oil pipe between the check valve 5 and the lifting hydraulic cylinder 6, the output shaft of the variable motor 10 is connected to the rotating shaft of the water pump 11, and the water pump The first interface of 11 is connected to the low-level water tank 12, the second interface is connected to the third interface of the second two-position three-way reversing valve 14, the first cooling water interface of the cooler 13 is communicated with the cooling water of the low-level water tank 12, and the second cooling water interface The water interface is connected with the second interface of the second two-position three-way reversing valve 14, and the first interface of the second two-position three-way reversing valve 14 is communicated with the cooling water of the high-level water tank 15; and the liquid level sensor 16 detects the high-level water tank. 15, and the detection signal is fed back to the controller 18, the temperature sensor 17 detects the temperature of the hydraulic oil in the hydraulic oil tank 1, and the detection signal is fed back to the controller 18, the first two-position three-way reversing valve 8 and the third The 2/2/3-way reversing valves 14 are all in communication with the controller 18 . After the whole system is assembled, it can be put into the control cabinet.

During the descending process of the lifting hydraulic cylinder 6, the controller 18 obtains the control signal through the temperature sensor 17 and the liquid level sensor 16, and realizes the automatic switching of the three working modes by controlling the reversing valve direction. The details are as follows:

1) Energy saving work - system cooling mode

When the lifting hydraulic cylinder 6 descends, the three-position four-way reversing valve 4 is in the right position. When the temperature sensor 17 detects that the oil temperature exceeds the pre-set temperature upper limit, the controller 18 controls the first two-position three-way The reversing valve 8 is in the right position, and the second two-position three-way reversing valve 14 is in the left position. At this time, the variable motor 10 drives the water pump 11 to work, and the water pump 11 drives the water into the cooler 13 to cool the oil. That is, the recovered energy is used to drive the water pump 11 to cool the hydraulic system.

2) Energy saving work-potential energy storage mode

When the lifting hydraulic cylinder 6 descends, the three-position four-way reversing valve 4 is in the right position, when the temperature sensor 17 detects that the oil temperature is within the temperature range set in advance, and the liquid level sensor 16 detects that the liquid level has not reached the advance When the upper limit of the liquid level is set, the controller 18 controls the first two-position three-way reversing valve 8 to be in the right position, and the second two-position three-way reversing valve 14 is in the right position. At this time, the variable motor 10 drives the water pump 11 When working, the water is pumped into the high-level water tank 15, and the potential energy recovered when the lifting hydraulic cylinder 6 is lowered is converted into the potential energy of water.

3) Normal working mode

When the lifting hydraulic cylinder 6 is lowered, the three-position four-way reversing valve 4 is in the right position. When the temperature sensor 17 detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor 16 detects that the liquid level reaches the pre-set temperature range. When the upper limit of the liquid level is determined, the controller 18 controls the first two-position three-way reversing valve 8 to be in the left position. At this time, the variable motor-water pump device does not work, and the potential energy of the lifting hydraulic cylinder cannot be recovered. The speed valve 9 flows back to the hydraulic oil tank 1 .

The above are the preferred embodiments of the present application, which do not limit the protection scope of the present invention. It should be pointed out that for those of ordinary skill in the technical field, some improvements can be made without departing from the technical principles of the present invention. and modifications, these improvements and modifications should also be considered as the scope of protection of the present application.

Claims (7)

1. An automatically controlled lifting hydraulic cylinder potential energy recovery system is characterized in that, comprising a hydraulic oil tank, a variable displacement pump, a relief valve, a three-position four-way reversing valve, a one-way valve, a lifting hydraulic cylinder, a first two position three Reversing valve, speed regulating valve, variable motor, water pump, low water tank, cooler, second two-position three-way reversing valve, high water tank, liquid level sensor, temperature sensor, controller and motor, The first oil port of the variable pump is communicated with the hydraulic oil in the hydraulic oil tank, the rotating shaft of the variable pump is connected to the electric motor, and the second oil port of the variable pump is commutated with the three-position four-way The second oil port of the valve is connected to the second oil port of the valve, the relief valve is connected in parallel with the variable pump, and the control oil circuit of the relief valve is connected to the oil pipe between the variable pump and the three-position four-way reversing valve. The third oil port of the three-position four-way reversing valve is connected to the first oil port of the one-way valve, the second oil port of the one-way valve is connected to the first oil port of the lifting hydraulic cylinder, and the The directional valve is unidirectionally connected from its first oil port to the second oil port, the fourth oil port of the three-position four-way reversing valve is connected to the second oil port of the lifting hydraulic cylinder, and the three-position four-way The first oil port of the reversing valve is closed, and the piston rod of the lifting hydraulic cylinder is connected with the load; The first oil port of the variable motor is connected to the second oil port of the cooler, the first oil port of the cooler is communicated with the hydraulic oil in the hydraulic oil tank, and the second oil port of the variable motor is connected The first oil port of the first two-position three-way reversing valve, the second oil port of the speed control valve is connected to the second oil port of the first two-position three-way reversing valve, the speed control valve The first oil port of the first oil port is connected to the oil pipe between the variable motor and the cooler, and the third oil port of the first two-position three-way reversing valve is connected to the oil pipe between the one-way valve and the lifting hydraulic cylinder, The output shaft of the variable motor is connected to the rotating shaft of the water pump, the first interface of the water pump is connected to the low-level water tank, the second interface is connected to the third interface of the second two-position three-way reversing valve, and the cooling The first cooling water port of the device is connected with the cooling water of the low-level water tank, and the second cooling water port is connected with the second port of the second two-position three-way reversing valve, and the second two-position three-way reversing valve The first port of the valve is in communication with the cooling water of the high-level water tank; and The liquid level sensor detects the water level of the high-level water tank and feeds back the detection signal to the controller, the temperature sensor detects the temperature of the hydraulic oil in the hydraulic oil tank, and feeds back the detection signal to the controller , the first two-position three-way reversing valve and the second two-position three-way reversing valve communicate with the controller. 2 . The automatically controlled lifting hydraulic cylinder potential energy recovery system according to claim 1 , wherein the controller adopts a logic control unit PLC. 3 . 3 . The automatically controlled lifting hydraulic cylinder potential energy recovery system according to claim 1 , wherein when the lifting hydraulic cylinder rises, the three-position four-way reversing valve is in the left position. 4 . 4 . The automatically controlled lifting hydraulic cylinder potential energy recovery system according to claim 1 , wherein the first two-position three-way reversing valve and the second two-position three-way reversing valve are electromagnetic reversing valves. 5 . . 5 . The automatically controlled lifting hydraulic cylinder potential energy recovery system according to claim 1 , wherein the variable displacement pump is a unidirectional variable displacement pump, and the variable displacement motor is a unidirectional variable displacement motor. 6 . 6 . The automatically controlled lifting hydraulic cylinder potential energy recovery system according to claim 5 , wherein all the pipelines through which the hydraulic oil passes are high-pressure steel wire pipes. 7 . 7. A method of utilizing the automatically controlled lifting hydraulic cylinder potential energy recovery system provided by one of claims 1 to 6, wherein the method comprises the following steps: S1: When the lifting hydraulic cylinder descends, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature exceeds the pre-set temperature upper limit, the controller controls the first two-position three-way reversing The valve is in the right position, and the second two-position three-way reversing valve is in the left position. At this time, the variable motor drives the water pump to work, and the water pump drives the water into the cooler to cool the oil, that is, the recovered energy is used to drive the water pump to Cooling the hydraulic system; S2: When the lifting hydraulic cylinder is lowered, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor detects that the liquid level does not reach the pre-set temperature range When the upper limit of the liquid level is reached, the controller controls the first two-position three-way reversing valve to be in the right position, and the second two-position three-way reversing valve is in the right position. At this time, the variable motor drives the water pump to work, and the water is pumped into the high position. The water tank converts the potential energy recovered when the lifting hydraulic cylinder is lowered into the potential energy of water; S3: When the lifting hydraulic cylinder is lowered, the three-position four-way reversing valve is in the right position. When the temperature sensor detects that the oil temperature is within the pre-set temperature range, and the liquid level sensor detects that the liquid level reaches the pre-set temperature range When the upper limit of the liquid level is reached, the controller controls the first two-position three-way reversing valve to be in the left position. At this time, the variable motor and water pump device do not work, and the potential energy of the lifting hydraulic cylinder cannot be recovered, and the oil flows back through the speed control valve. Hydraulic tank.

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