CN113148914B - Forklift potential energy recovery and release integrated device and working method - Google Patents

Abstract

The invention discloses a forklift potential energy recovery and release integrated device and a working method thereof, wherein the device integrates the recovery and release of gravitational potential energy, and realizes the recovery and release of energy through the same set of energy recovery and release units: in the process that the lifting oil cylinder drives the heavy object to be lowered, the hydraulic pump motor is used as a motor, the motor generator is used as a generator, pressure oil in the second rodless cavity of the lifting oil cylinder flows into the motor to push the motor to drive the generator to work, and output electric energy is stored in the storage battery; or the pressure oil in the second rodless cavity of the lifting oil cylinder flows into the first rodless cavity of the tilting oil cylinder to drive the tilting oil cylinder to act, so that the recovery of energy is completed. In the lifting process, the motor generator works in a motor state to draw electric energy from the storage battery, the hydraulic pump motor works in a hydraulic pump state to increase pressure oil for the system, the piston rod of the lifting oil cylinder or the piston rod of the tilting oil cylinder is pushed to extend out, and the lifting action is completed, and the lifting action is the energy release process.

Description

Forklift potential energy recovery and release integrated device and working method

Technical field

The invention relates to an integrated device and working method for recovering and releasing potential energy of a forklift.

Background technique

Forklifts refer to various wheeled transport vehicles that are used for loading, unloading, stacking and short-distance transportation of palletized goods. It is a commonly used lifting tool and is usually driven by an engine or motor. Its working principle is that the engine or motor The hydraulic pump is driven to generate hydraulic energy, thereby lifting the cylinder and converting the hydraulic energy into the gravitational potential energy of the cargo.

Electric forklifts use batteries as energy and use electric motors instead of engines to drive the hydraulic system to complete the lifting, lowering, transfer, and unloading of goods. Since the forklift contains a large amount of potential energy in the process of driving the heavy object down, traditional forklifts consume this energy on the throttle valve port, which on the one hand causes a large amount of energy loss and on the other hand increases the oil temperature. , affecting the life of hydraulic components and oil, and may cause problems such as leakage and unstable work. At present, for the research on the potential energy of forklifts, some studies use hydraulic accumulators to store the pressure oil of the lifting cylinder during the process of lowering the heavy objects. However, because the pressure of the accumulator gradually increases with the increase of the recovered pressure oil, causing heavy damage. The controllability of the object changes during the descent of the object; another part of the research uses an electrical energy recovery method, using a separate hydraulic motor-generator connected to the rodless cavity of the lifting cylinder; when the lifting cylinder drives the weight to descend, the lift The hydraulic oil in the rodless cavity of the lifting cylinder flows into the hydraulic motor to drive the generator to generate electricity, and the electric energy is stored in the battery. During lifting or other working conditions, the stored electrical energy is released. In this working method, the energy recovery system and the release system are two different systems. There are multiple energy conversions. The system is complex and the efficiency is low. In order to simplify the system and improve energy utilization efficiency, integrating recovery and release is an important direction of research.

Contents of the invention

The invention provides an integrated device and working method for recovering and releasing potential energy of a forklift, which overcomes the shortcomings of the background technology. One of the technical solutions adopted by the present invention to solve its technical problems is:

Forklift potential energy recovery and release integrated device, which includes: tilt cylinder, lifting cylinder, three-position four-way electromagnetic reversing valve, first two-position two-way electromagnetic reversing valve, second two-position two-way electromagnetic reversing valve , energy recovery and release unit, motor controller and battery. The tilt cylinder includes a first rod chamber and a first rodless chamber. The three-position four-way electromagnetic reversing valve is connected with the first rod chamber and the first rodless chamber. The rod cavity, the second two-position two-way electromagnetic reversing valve and the energy recovery and release unit are all connected, the energy recovery and release unit is connected to the motor controller, and the motor controller is connected to the battery; the lifting cylinder includes a second rod cavity and the second rodless cavity. The second rodless cavity is connected to the first two-position two-way electromagnetic reversing valve. The first two-position two-way electromagnetic reversing valve is connected to the second two-position two-way electromagnetic reversing valve and energy recovery. are connected to the release unit, and the second two-position two-way electromagnetic reversing valve is connected to the energy recovery and release unit.

In a preferred embodiment: the energy recovery and release unit includes a hydraulic pump motor, an electric generator and a first oil tank. The hydraulic pump motor is in phase with the electric generator, a three-position four-way electromagnetic reversing valve, and the first oil tank. Connection, the motor generator is connected to the motor controller.

In a preferred embodiment: the hydraulic pump motor and the electric generator are coaxially arranged.

In a preferred embodiment: the device also includes a first one-way valve and a second one-way valve, the inlet of the first one-way valve is connected to the hydraulic pump motor and the outlet of the second one-way valve, and its outlet is connected to the three The four-position electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve are all connected; the inlet of the second one-way valve is connected with the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve. The valves are all connected, and the outlet of the second one-way valve is connected to the hydraulic pump motor.

In a preferred embodiment: the device further includes a throttle valve connected between the first two-position two-way electromagnetic reversing valve and the inlet of the second one-way valve.

In a preferred embodiment: the device further includes a relief valve and a second oil tank. The relief valve inlet is connected to the hydraulic pump motor, the first one-way valve inlet and the second one-way valve outlet. The relief valve outlet is connected to the hydraulic pump motor, the first one-way valve inlet and the second one-way valve outlet. The second fuel tank is connected.

In a preferred embodiment: the device further includes an oil supply check valve and a third oil tank. The oil supply check valve inlet is connected to the third oil tank. The oil supply check valve outlet is connected to the relief valve inlet and the hydraulic pump. The motor and the first one-way valve inlet are connected.

In a preferred embodiment: there are two lifting cylinders, and the second rodless chambers of the two lifting cylinders are connected to the first two-position two-way electromagnetic reversing valve.

The second technical solution adopted by the present invention to solve the technical problem is:

The working method of forklift potential energy recovery and release integration, which uses the forklift potential energy recovery and release integrated device, includes:

There are two states when the forklift potential energy is recovered:

When the lifting cylinder is driven to lower the heavy object, the three-position four-way electromagnetic reversing valve is in the neutral position and the tilt cylinder does not work. At this time, the first two-position two-way electromagnetic reversing valve is energized, and the second two-position two-way electromagnetic reversing valve is energized. When the reversing valve is not powered, the pressure oil in the second rodless chamber of the lifting cylinder flows into the hydraulic pump motor through the first two-position two-way electromagnetic reversing valve, the throttle valve, and the second one-way valve. The hydraulic pump motor 11 When used as a motor, the electric generator is in a power-generating state, and the electric energy is stored in the battery through the motor controller; due to the existence of the hydraulic pump motor, the pressure difference between the two ends of the throttle valve can be adjusted, thereby achieving precise control of the descent speed;

or,

When the lifting cylinder is driven to lower the heavy object, the left or right position of the three-position four-way electromagnetic reversing valve works. The tilt cylinder is in working condition and its working pressure is lower than the pressure of the second rodless chamber of the lifting cylinder. At this time, the first 2-position 2-way electromagnetic directional valve and the second 2-position 2-way electromagnetic directional valve are both energized, and the pressure oil in the second rodless chamber of the lifting cylinder passes through the first 2-position 2-way electromagnetic directional valve, The left or right position of the second two-position two-way electromagnetic reversing valve and the three-position four-way electromagnetic reversing valve flows into the first rodless cavity of the tilt cylinder, prompting the tilt cylinder to drive the heavy object to tilt forward and backward. tilt;

There are two states when energy is released:

When the lifting cylinder drives the fork to lift, the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve are both energized. At this time, the energy stored in the battery is supplied to the motor generator to It is in the motor state, and the hydraulic pump motor is used as a hydraulic pump. The hydraulic pump outputs pressure oil to the outside. The pressure oil passes through the first one-way valve, the second two-position two-way electromagnetic reversing valve and the first two-position two-way electromagnetic reversing valve. The directional valve enters the second rodless cavity of the lifting cylinder, and pushes the lifting cylinder to drive the fork to complete the lifting action, realizing the reuse of recovered energy;

or,

When the tilting cylinder is driven and the lifting cylinder is not working, the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve are not energized, and the three-position four-way electromagnetic reversing valve is energized and is on the left It works in the first or right position. At this time, the energy stored in the battery is supplied to the motor generator so that it is in the motor state. The hydraulic pump motor is used as a hydraulic pump. The hydraulic pump outputs pressure oil to the outside. The pressure oil output by the hydraulic pump passes through The first one-way valve and the three-position four-way electromagnetic reversing valve flow into the first rodless cavity of the tilt cylinder, prompting it to drive the fork to tilt forward or backward, realizing the reuse of recovered energy.

Compared with the background technology, this technical solution has the following advantages:

1. This device integrates the recovery and release of gravitational potential energy, and realizes energy recovery and release through the same energy recovery and release unit: when the lifting cylinder drives the weight to lower, the hydraulic pump motor is used as a motor, and the electric power is generated The machine is used as a generator. The pressure oil in the second rodless chamber of the lifting cylinder flows into the motor to push the motor to drive the generator. The output electric energy is stored in the battery to complete energy recovery. During the lifting process, the electric generator works in the motor state and draws electric energy from the battery. The hydraulic pump motor works in the hydraulic pump state, increasing the pressure oil for the system and pushing the piston rod of the lifting cylinder to extend to complete the lifting action. This is the energy release process.

2. In terms of energy release, on the one hand, it can be released through the energy recovery and release unit to continue to push the lifting cylinder to work; on the other hand, when the working pressure of the tilt cylinder is lower than the pressure of the second rodless chamber of the lifting cylinder, The pressure oil in the second rodless chamber of the lift cylinder can directly flow into the tilt cylinder, pushing the tilt cylinder to complete related operations. At this time, since the pressure oil-pressure oil is directly used, there is no energy conversion, so the efficiency is high.

Description of the drawings

The present invention will be further described below in conjunction with the accompanying drawings and examples.

Figure 1 illustrates an overall structural block diagram of a device for integrating potential energy recovery and release of a forklift according to a preferred embodiment.

Detailed ways

In the claims, description and above-mentioned drawings of the present invention, unless otherwise expressly limited, the terms "first", "second" or "third" are used to distinguish different objects and are not used for Describe a specific sequence.

In the claims, description and above-mentioned drawings of the present invention, unless otherwise expressly limited, the terms "center", "horizontal", "vertical", "horizontal", "vertical" and "top" are used for directional terms. , "bottom", "inside", "outside", "up", "down", "front", "back", "left", "right", "clockwise", "counterclockwise" and other directions or The positional relationships are based on the orientations and positional relationships shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation or be constructed and operated in a specific orientation. , therefore it cannot be understood as limiting the specific protection scope of the present invention.

In the claims, description and above-mentioned drawings of the present invention, unless otherwise expressly limited, if the terms "fixed connection" and "fixed connection" are used, they should be understood in a broad sense, that is, there is no displacement relationship or relative rotation relationship between the two. Any connection method, that is to say, including non-detachable fixed connection, detachable fixed connection, integration and fixed connection through other devices or components.

In the claims, description, and above-mentioned drawings of the present invention, if the terms "include," "have," and their variations are used, they are intended to mean "including but not limited to."

Please refer to Figure 1, which is a preferred embodiment of a device for integrating potential energy recovery and release for a forklift. The device for integrating potential energy recovery and release for a forklift includes a tilt cylinder 1 and a lifting cylinder 2.1 and 2.2. , three-position four-way electromagnetic reversing valve 3, first two-position two-way electromagnetic reversing valve 4, second two-position two-way electromagnetic reversing valve 5, energy recovery and release unit 20, motor controller 13 and battery 14.

The tilt cylinder 1 includes a first rod cavity and a first rodless cavity, and the three-position four-way electromagnetic reversing valve 3 is connected to the first rod cavity, the first rodless cavity, and the second two-position two-way electromagnetic reversing valve. The reversing valve 5 and the energy recovery and release unit 20 are connected, the energy recovery and release unit 20 is connected to the motor controller 13, the motor controller 13 is connected to the battery 14; the lifting cylinders 2.1 and 2.2 include a second rod chamber and a third Two rodless chambers, the second rodless chamber is connected to the first two-position two-way electromagnetic reversing valve 4, and the first two-position two-way electromagnetic reversing valve 4 is connected to the second two-position two-way electromagnetic reversing valve 5. Energy The recovery and release units 20 are both connected, and the second two-position two-way electromagnetic reversing valve 5 is connected with the energy recovery and release unit 20 .

In this embodiment, there are two lifting cylinders 2.1 and 2.2, and the second rodless chambers of the two lifting cylinders 2.1 and 2.2 are connected to the first two-position two-way electromagnetic reversing valve 4.

In this embodiment, the energy recovery and release unit 20 includes a hydraulic pump motor 11, an electric generator 12 and a first oil tank 15. The hydraulic pump motor 11 and electric generator 12, a three-position four-way electromagnetic reversing valve 3, and a third A fuel tank 15 is connected to each other, and the motor generator 12 is connected to the motor controller 13 . Preferably, the hydraulic pump motor 11 and the electric generator 12 are arranged coaxially to reduce friction and improve efficiency.

In this embodiment, the device also includes a first one-way valve 6 and a second one-way valve 7. The inlet of the first one-way valve 6 is connected to the hydraulic pump motor 11 and the outlet of the second one-way valve 7. It is connected to the three-position four-way electromagnetic reversing valve 3 and the second two-position two-way electromagnetic reversing valve 5; the inlet of the second one-way valve 7 is connected to the first two-position two-way electromagnetic reversing valve 4 and the second two-position electromagnetic reversing valve 5. The two-way electromagnetic reversing valves 5 are all connected, and the outlet of the second one-way valve 7 is connected to the hydraulic pump motor 11.

In this embodiment, the device also includes a throttle valve 8 connected between the first two-position two-way electromagnetic reversing valve 4 and the inlet of the second one-way valve 7 .

In this embodiment, the device also includes a relief valve 9 and a second oil tank 17. The inlet of the relief valve 9 is connected to the hydraulic pump motor 11, the inlet of the first one-way valve 6 and the outlet of the second one-way valve 7. The outlet of valve 9 is connected with the second oil tank 17 .

In this embodiment, the device also includes an oil supply check valve 10 and a third oil tank 16. The oil supply check valve 10 has an inlet connected to the third oil tank 16, and the oil supply check valve 10 has an outlet connected to the relief valve 9 inlet. , hydraulic pump motor 11, and the inlet of the first one-way valve 6 are all connected.

The working method of the forklift potential energy recovery and release integrated device includes:

There are two states when the forklift potential energy is recovered:

When the operating handle of the forklift drives the lifting cylinders 2.1 and 2.2 to lower the heavy object, the three-position four-way electromagnetic reversing valve 3 is in the neutral position and the tilt cylinder 1 does not work. At this time, the first two-position two-way electromagnetic reversing valve 4 is energized, and the second two-position two-way electromagnetic reversing valve 5 is de-energized. The pressure oil in the second rodless chamber of the lifting cylinders 2.1 and 2.2 passes through the first two-position two-way electromagnetic reversing valve 4, throttle valve 8, After the second one-way valve 7 flows into the hydraulic pump motor 11, the hydraulic pump motor 11 is used as a motor to drive the electric generator 12 to generate electricity, and the electric energy is stored in the battery 14 through the motor controller 13; due to the power of the hydraulic pump motor 11 Yes, the pressure difference between the two ends of the throttle valve 8 can be adjusted to achieve precise control of the descending speed;

or,

When the lifting cylinders 2.1 and 2.2 are driven to lower the heavy object, the left or right position of the three-position four-way electromagnetic reversing valve 3 works. The tilt cylinder 1 is in working condition and its working pressure is lower than that of the lifting cylinders 2.1 and 2.2. The pressure of the second rodless chamber. At this time, the first two-position two-way electromagnetic reversing valve 4 and the second two-position two-way electromagnetic reversing valve 5 are both energized, and the pressure of the second rodless chamber of the lifting cylinders 2.1 and 2.2 The oil passes through the left or right position of the first two-position two-way electromagnetic reversing valve 4, the second two-position two-way electromagnetic reversing valve 5 and the three-position four-way electromagnetic reversing valve 3 and then flows into the first part of the tilt cylinder 1. In the rodless cavity, the tilt cylinder 1 drives the weight to tilt forward and backward;

There are two states when energy is released:

When the lifting cylinders 2.1 and 2.2 are driven to drive the forks to lift, the first two-position two-way electromagnetic reversing valve 4 and the second two-position two-way electromagnetic reversing valve 5 are both energized. At this time, the energy stored in the battery 14 The motor generator 12 is supplied to make it in the motor state. The hydraulic pump motor 11 is used as a hydraulic pump. The hydraulic pump outputs pressure oil to the outside. The pressure oil passes through the first one-way valve 6 and the second two-position two-way electromagnetic reversing valve. 5 and the first two-position two-way electromagnetic reversing valve 4 enter the second rodless cavity of the lifting cylinders 2.1 and 2.2, and push the lifting cylinders 2.1 and 2.2 to drive the forks to complete the lifting action, realizing the reuse of recovered energy. ;

or,

When the tilting cylinder 1 is driven and the lifting cylinder 2 is not working, neither the first two-position two-way electromagnetic reversing valve 4 nor the second two-position two-way electromagnetic reversing valve 5 is energized, and the three-position four-way electromagnetic reversing valve 3 is powered on and works in the left or right position. At this time, the energy stored in the battery 14 is supplied to the motor generator 12 so that it is in the motor state. The hydraulic pump motor 11 is used as a hydraulic pump, and the hydraulic pump outputs pressure oil to the outside. , the pressure oil output by the hydraulic pump flows into the first rodless chamber of the tilt cylinder 1 after passing through the first one-way valve 6 and the three-position four-way electromagnetic reversing valve 3, prompting it to drive the fork to tilt forward or backward. Realize the reuse of recovered energy.

The above are only preferred embodiments of the present invention, and therefore cannot be used to limit the scope of the present invention. That is, equivalent changes and modifications made based on the patent scope of the present invention and the content of the specification should still be covered by the present invention. within the range.

Claims (6)

1. The forklift potential energy recovery and release integrated device is characterized by: it includes: tilt cylinder, lifting cylinder, three-position four-way electromagnetic reversing valve, first two-position two-way electromagnetic reversing valve, second two-position electromagnetic reversing valve A two-way electromagnetic reversing valve, an energy recovery and release unit, a motor controller and a battery. The tilt cylinder includes a first rod cavity and a first rodless cavity. The three-position four-way electromagnetic reversing valve is connected to the first rodless cavity. The rod cavity, the first rodless cavity, the second two-position two-way electromagnetic reversing valve and the energy recovery and release unit are all connected, the energy recovery and release unit is connected to the motor controller, and the motor controller is connected to the battery; the lifting cylinder It includes a second rodless cavity and a second rodless cavity. The second rodless cavity is connected to the first two-position two-way electromagnetic reversing valve. The first two-position two-way electromagnetic reversing valve is connected to the second two-position two-way electromagnetic reversing valve. The reversing valve, energy recovery and release unit are all connected, and the second two-position two-way electromagnetic reversing valve is connected with the energy recovery and release unit; The energy recovery and release unit includes a hydraulic pump motor, an electric generator and a first oil tank. The hydraulic pump motor is connected to the electric generator, a three-position four-way electromagnetic reversing valve, and the first oil tank. The electric generator is connected to the motor control unit. devices connected; The device also includes a first one-way valve and a second one-way valve. The inlet of the first one-way valve is connected to the hydraulic pump motor and the outlet of the second one-way valve. Its outlet is connected to the three-position four-way electromagnetic reversing valve. The second two-position two-way electromagnetic reversing valve is connected to each other; the inlet of the second one-way valve is connected to the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve. The valve outlet is connected to the hydraulic pump motor. 2. The integrated device for recovering and releasing potential energy of a forklift according to claim 1, characterized in that: the device further includes a throttle valve connected between the first two-position two-way electromagnetic reversing valve and the second between the inlets of the one-way valve. 3. The integrated device for recovering and releasing potential energy of a forklift according to claim 2, characterized in that: the device further includes a relief valve and a second oil tank, and the inlet of the relief valve is connected to a hydraulic pump motor and a first one-way valve. The inlet and the outlet of the second one-way valve, the outlet of the relief valve are connected with the second oil tank. 4. The integrated device for recovering and releasing potential energy of a forklift according to claim 3, characterized in that: the device further includes an oil replenishment check valve and a third oil tank, and the inlet of the oil replenishment check valve is connected to the third oil tank. The outlet of the oil supply check valve is connected to the inlet of the relief valve, the hydraulic pump motor, and the inlet of the first check valve. 5. The integrated device for recovering and releasing potential energy of a forklift according to claim 4, characterized in that: there are two lifting cylinders, and the second rodless chambers of the two lifting cylinders are connected to the first two positions. The two-way electromagnetic reversing valve is connected. 6. A working method for integrating recovery and release of potential energy of a forklift, which uses the device for integrating recovery and release of potential energy of a forklift according to any one of claims 4 to 5, and is characterized by: including: There are two states when the forklift potential energy is recovered: When the lifting cylinder is driven to lower the heavy object, the three-position four-way electromagnetic reversing valve is in the neutral position and the tilt cylinder does not work. At this time, the first two-position two-way electromagnetic reversing valve is energized, and the second two-position two-way electromagnetic reversing valve is energized. The reversing valve is not energized, and the pressure oil in the second rodless chamber of the lifting cylinder flows into the hydraulic pump motor through the first two-position two-way electromagnetic reversing valve, the throttle valve, and the second one-way valve. The hydraulic pump motor serves as When the motor is used, the motor-generator is in the power-generating state, and the electric energy is stored in the battery through the motor controller; due to the existence of the hydraulic pump motor, the pressure difference between the two ends of the throttle valve can be adjusted, thereby achieving precise control of the descent speed; or, When the lifting cylinder is driven to lower the heavy object, the left or right position of the three-position four-way electromagnetic reversing valve works. The tilt cylinder is in working condition and its working pressure is lower than the pressure of the second rodless chamber of the lifting cylinder. At this time, the first 2-position 2-way electromagnetic directional valve and the second 2-position 2-way electromagnetic directional valve are both energized, and the pressure oil in the second rodless chamber of the lifting cylinder passes through the first 2-position 2-way electromagnetic directional valve, The left or right position of the second two-position two-way electromagnetic reversing valve and the three-position four-way electromagnetic reversing valve flows into the first rodless cavity of the tilt cylinder, prompting the tilt cylinder to drive the heavy object to tilt forward and backward. tilt; There are two states when energy is released: When the lifting cylinder drives the fork to lift, the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve are both energized. At this time, the energy stored in the battery is supplied to the motor generator to It is in the motor state, and the hydraulic pump motor is used as a hydraulic pump. The hydraulic pump outputs pressure oil to the outside. The pressure oil passes through the first one-way valve, the second two-position two-way electromagnetic reversing valve and the first two-position two-way electromagnetic reversing valve. The directional valve enters the second rodless cavity of the lifting cylinder, and pushes the lifting cylinder to drive the fork to complete the lifting action, realizing the reuse of recovered energy; or, When the tilting cylinder is driven and the lifting cylinder is not working, the first two-position two-way electromagnetic reversing valve and the second two-position two-way electromagnetic reversing valve are not energized, and the three-position four-way electromagnetic reversing valve is energized and is on the left It works in the first or right position. At this time, the energy stored in the battery is supplied to the motor generator so that it is in the motor state. The hydraulic pump motor is used as a hydraulic pump. The hydraulic pump outputs pressure oil to the outside. The pressure oil output by the hydraulic pump passes through The first one-way valve and the three-position four-way electromagnetic reversing valve flow into the first rodless cavity of the tilt cylinder, prompting it to drive the fork to tilt forward or backward, realizing the reuse of recovered energy.