CN204512035U - A kind of hydraulic energy-saving controller - Google Patents

Abstract

A hydraulic energy-saving controller, comprising a high-pressure oil inlet 1, a low-pressure oil inlet 2, an oil outlet 9, a high-speed switch valve 4, a one-way valve 5, an inertia device 6, a two-position three-way high-speed reversing valve 7 and an accumulator energy device 8. The PWM signal is used as the control signal 3 of the valve in the hydraulic energy-saving controller. By controlling the switching timing of the high-speed switching valve and repeating the above working process, the oil outlet can continuously output stable pressure and flow, so that the excess energy of the high-pressure oil can be used to do work and achieve the effect of energy saving. By adjusting the PWM control signal The air ratio can realize the adjustment of the output pressure and flow, that is, by controlling the time of the high-pressure oil port and the low-pressure oil supply port, the total energy input can always be controlled to match the energy required by the load, and finally the goal of energy saving and high efficiency can be achieved.

Description

A hydraulic energy-saving controller

technical field

The utility model relates to a hydraulic energy-saving controller.

Background technique

In recent years, mobile robots have made great progress in the fields of structure, perception, path planning, and control, and have realized complex functions such as entertainment services, human-computer interaction, and extreme environment detection. limited, which restricts the practical application of mobile robots. Existing studies have shown that when the output pressure of the power source exceeds 3.5MPa, the hydraulic drive system with the same power has a higher power density than the pure electromechanical drive system. Adopting hydraulic drive system is an effective way to improve load capacity. At present, many research institutes are beginning to try to use hydraulic power systems to drive mobile robots, such as BIGDOG and petman developed by Boston Dynamics, KenKen II hydraulically driven quadruped robots of the Italian Polytechnic University, and high-performance robots funded by China's 863 High-tech Research and Development Program. The quadruped robot project explicitly calls for a hydraulic drive system.

Due to weight and volume limitations, the hydraulic drive system of mobile robots adopts a single pump source-multi-actuator system structure. The efficiency of this type of hydraulic drive system is very low. The main reason is that the load of each actuator is different at the same time, and the load of the same actuator is also different at different times. One pump source cannot simultaneously provide power to the loads of multiple actuators. Matching, the load of high-power actuators is generally selected for matching. The current method of controlling actuators is the proportional throttling control method, which leads to a large amount of throttling loss in the actuator branch with low load, resulting in low efficiency.

Inefficiency will cause the following problems: the power requirement of the power source is high, and the weight and volume of the power source will increase; the energy (such as gasoline) required to complete the same work will increase, and the weight will increase; the performance index requirements of the hydraulic components of the system will increase, and the hydraulic components will The weight and volume of the cooling system will increase; the heating of the system will be more serious, the power of the cooling system will become larger, and the volume and weight of the cooling system will increase. Therefore, the inefficiency will seriously affect the payload capacity of the mobile robot.

Utility model content

The purpose of this utility model is to provide an energy-saving controller and a control method that can effectively improve the efficiency of the hydraulic drive system of a mobile robot for the deficiencies of the prior art. The method realizes the matching of the output power and the load power by adjusting the pulse width of the PWM signal. Finally, the purpose of improving the efficiency of the hydraulic system is achieved. The utility model realizes above-mentioned object through following technical scheme.

A hydraulic energy-saving controller, comprising a high-pressure oil inlet, a low-pressure oil inlet, and an oil outlet connected to an actuator. The high-pressure oil inlet communicates with the actuator through an energy-saving system, and the energy-saving system includes a first high-speed On-off valve, second high-speed on-off valve, reversing valve and inertial device, the inertial device includes a mass block, the two sides of the mass block are symmetrically provided with a hydraulic piston, and the end of the piston rod of the hydraulic piston is installed on the On both sides of the mass block, the high-pressure oil inlet communicates with the rodless cavity of the hydraulic piston at both ends of the inertial device through the pipeline and the first high-speed on-off valve and the second high-speed on-off valve arranged on the pipeline respectively. The rodless chamber of the hydraulic piston is respectively connected to the oil inlet A and the oil inlet B of the reversing valve through the oil circuit, the oil outlet C of the reversing valve is connected with the actuator, and the oil outlet of the reversing valve An accumulator is also connected in parallel on the oil path between the port C and the actuator, and the rodless chambers of the two hydraulic pistons of the inertial device are also communicated with the low-pressure oil inlet.

The first one-way valves to prevent hydraulic oil from flowing back to the inertial device are respectively installed on the oil paths between the rodless chambers of the two hydraulic pistons of the inertial device and the oil inlet A and oil inlet B of the reversing valve. A second one-way valve is installed on the oil circuit between the reversing valve and the actuator to prevent the hydraulic oil from flowing back to the oil outlet C. A third non-return valve is installed on the oil circuit between them to prevent hydraulic oil from flowing back to the low-pressure oil inlet.

It includes two sets of energy-saving systems, and the oil outlets C of the reversing valves of the two sets of energy-saving systems are connected.

The reversing valve is a two-position three-way high-speed reversing valve.

The hydraulic piston is installed on the support frame and is wrapped with a protective cover, and an elastic stopper is provided on the opposite surface of the hydraulic piston to the mass block to prevent collision damage.

The cylinder barrel of the hydraulic piston is a high-pressure straight pipe with high pressure resistance.

The end cover of the hydraulic piston is fixed on both ends of the protective cover by screws, and an elastic gasket is arranged between the end cover and the protective cover.

Both the high-speed switching valve and the reversing valve use PWM signals as control signals.

Due to the adoption of the above-mentioned structure, this device sets an energy-saving system between the high-pressure oil inlet and the actuator. On the one hand, the hydraulic energy of the high-pressure oil through the energy-saving system supplies energy to the actuator; The mass block accelerates and converts excess hydraulic energy into kinetic energy of the mass block. At the same time, the mass block pushes out the hydraulic oil in the high-pressure straight pipe at the other end, and the discharged hydraulic oil flows to the actuator through the reversing valve. When the high-speed switching valve is closed state, the high-pressure oil inlet is cut off, and the mass block continues to move under the action of inertia to suck the hydraulic oil from the low-pressure oil inlet into the hydraulic piston cavity on one side of the inertial device, and the piston on the other end of the mass block will Continue to push out the hydraulic oil in the cylinder, the discharged hydraulic oil flows to the actuator through the reversing valve, and the mass block decelerates under the action of hydraulic thrust until the speed decreases to zero, at this time the kinetic energy of the mass block is completely converted into hydraulic energy. By controlling the opening and closing timing of the high-speed switching valve and repeating the above working process, the oil outlet can continuously output stable pressure and flow, so that the excess energy of the high-pressure oil can be used to do work and achieve energy-saving effects.

The PWM signal is used as the control signal of the valve in the utility model (PWM signal is a periodic signal with adjustable pulse width. This signal is a mature technology and can be obtained by various means. It is relatively simple and efficient to adopt this kind of signal control, and the signal is easy. get). When the amplitude of the control signal is 1, the high-speed switching valve port is opened, and when the amplitude is 0, the high-speed switching valve port is closed. When the amplitude of the control signal is 1, port B and port C of the two-position three-way valve are connected, and when the amplitude is 0, port A and port C of the two-position three-way valve are connected.

In summary, the utility model can realize the output pressure by adjusting the duty cycle of the PWM control signal, (the duty cycle is the ratio of the time occupied by the amplitude of 1 (pulse width) in one cycle to one cycle time.) And the flow is matched with the load pressure and flow, that is, by controlling the time of the high-pressure oil port and the low-pressure oil supply port, the total energy input is always matched with the energy required by the load, and the ultimate goal of energy saving and high efficiency is achieved. Compared with the prior art, this patent is more energy-saving (that is, reduces the consumption of gasoline). Energy-saving can reduce the weight and volume of the power source, reduce the weight of gasoline carried, and reduce the weight and volume of the radiator, thereby reducing the robot Its own weight, thereby increasing the weight of the load that the robot can carry. The utility model can be used on various small and medium-sized mobile platforms with large variations in the load of each actuator with energy autonomy, such as biped robots, quadruped robots, small unmanned excavators, exoskeleton equipment, etc., and can effectively improve the performance of such equipment. Improve the efficiency of the hydraulic drive system, thereby improving its load capacity, promoting its further practical application, and at the same time realizing energy saving and environmental protection, which has good economic value.

Description of drawings

Fig. 1 schematic diagram of the utility model;

Fig. 2 is the structural representation of the inertia device of the utility model;

Fig. 3 (a) the working process schematic diagram of the present utility model;

Fig. 3 (b) schematic diagram of the working process of the utility model;

The valve control signal schematic diagram of Fig. 4 the utility model;

Fig. 5 is an application example of the utility model: a schematic diagram of load changes that can be matched with different duty ratios K.

Detailed ways

Below in conjunction with accompanying drawing, the specific implementation manner of this patent is described in further detail.

Embodiment: As shown in FIG. 1 , in this example, two sets of energy-saving systems are set. The hydraulic energy-saving controller has three oil ports, a high-pressure oil inlet 1 , a low-pressure oil inlet 2 and an oil outlet 9 . Each set of energy-saving system has the same structure including high-speed on-off valve 4, one-way valve 5, inertial device 6 and reversing valve 7. In this example, the first energy-saving system includes first high-speed on-off valve 41, second high-speed on-off valve 43, An inertial device 61, a one-way valve and a first reversing valve 71, the second energy-saving system includes a third high-speed switching valve 42, a fourth high-speed switching valve 44, a one-way valve, a second inertial device 62 and a second reversing valve 72. The reversing valve is a two-position three-way high-speed reversing valve with oil inlet ports A and B, and oil outlet port C. The rodless chambers of the two hydraulic pistons of the first inertial device are connected to the first reversing valve. Check valves 52 and 53 are respectively installed on the oil circuit between the oil inlet A and the oil inlet B of the valve to prevent the hydraulic oil from flowing back to the first inertial device. A non-return valve 59 is also installed on the oil circuit to prevent the hydraulic oil from flowing back to the oil outlet C, and a check valve 59 is installed on the oil circuit between the rodless chamber of the two hydraulic pistons of the first inertial device and the low-pressure oil inlet to prevent the hydraulic oil from flowing back to the oil outlet C. The one-way valves 51 and 54 that return to the low-pressure oil inlet; the oil passage between the rodless cavity of the two hydraulic pistons of the second inertial device and the oil inlet A and oil inlet B of the second reversing valve One-way valves 56 and 58 are respectively installed to prevent hydraulic oil from flowing back to the second inertial device, and the hydraulic oil is installed on the oil circuit between the rodless chamber of the two hydraulic pistons of the second inertial device and the low-pressure oil inlet to prevent hydraulic oil from flowing back to the second inertial device. The one-way valves 55 and 57 that return to the low-pressure oil inlet, because the first energy-saving system and the second energy-saving system have the same structure, so the first energy-saving system is used as an example to describe here. port 1, and the other end communicates with the rodless chamber of the hydraulic piston at both ends of the first inertial device 61, and the rodless chamber of the hydraulic piston is also connected with the low pressure inlet, the oil inlet A and the oil inlet B of the first reversing valve respectively. The oil outlet C of the reversing valve 61 is connected to the outlet 9, and the outlet is connected to the actuator, and an accumulator 8 is connected in parallel on the oil path between the check valve 59 and the outlet 9.

The actual structure of the energy-saving controller is limited by the external dimensions and installation structure of the selected high-speed valves and accumulators, as well as the layout space of the specific use object, and its structure can be designed arbitrarily. Wherein, this patent provides a specific structure of the core component inertial device 6, as shown in FIG. 2 . The inertial device 6 adopts a symmetrical structure design, and is composed of an oil port 611, an end cover 612, an elastic gasket 613, a support frame 614, an elastic stopper 615, a high-pressure straight pipe 616, a mass block 617, and an outer protective cover 618. The oil ports 611 are located at both ends of the inertial device 61 and are respectively connected to one end of a high-pressure straight pipe 616 . The end caps 611 are fixed on both ends of the protective cover 618 by screws, and elastic gaskets 613 are placed below to ensure that the end caps 611 can compress the high-pressure straight pipe 616 when the screws are tightened. Mass block 617 is made up of mass block 6173 and piston rod 6172 and piston 6171 at both ends. Piston 6171 slides in high pressure straight pipe 616. An elastic block 615 is installed on the end surface of the high-pressure straight pipe 616 in contact with the mass block 6173 to prevent the mass block 616 from colliding with the high-pressure straight pipe 616 . The mass block can only be supported by the pistons at both ends, and the frictional resistance and gravity generated by the mass of the mass block can be ignored compared to the thrust generated by the hydraulic oil.

Working principle of the utility model: a working process of the hydraulic energy-saving controller is shown in Figure 3, and the working process includes two stages of energy storage and release of the inertial device. Figure 3(a) shows the energy storage process, and the dotted arrow indicates the hydraulic oil flow circuit. At this time, the high-speed on-off valve 41 is in the open state, the high-speed on-off valve 43 is in the closed state, and the hydraulic oil enters the inertial device 6 from the high-pressure oil port 1 . Port B and port C of the two-position three-way valve 71 are connected. At this time, the pressure p _S of the high-pressure oil port 1 is higher than the load pressure p _L , and the mass block 617 in the inertial device accelerates to move to the right under the action of the hydraulic thrust, so the excess hydraulic energy is converted into the kinetic energy E of the mass block, namely:

$\mathrm{<span\; class="notranslate">\; E.</span>}<span\; class="notranslate">\; =</span>\frac{\mathrm{<span\; class="notranslate">\; 1</span>}}{\mathrm{<span\; class="notranslate">\; 2</span>}}{\mathrm{<span\; class="notranslate">\; mv</span>}}^{\mathrm{<span\; class="notranslate">\; 2</span>}}$

$\mathrm{<span\; class="notranslate">\; m</span>}\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; S</span>}$

Wherein, v is the velocity of the mass block, m is the mass of the mass block, and S is the cross-sectional area of the piston 6171 of the mass block. During this process, due to the continuous increase of the speed of the mass block, the flow discharged from the inertial device increases. At this time, the accumulator 8 absorbs the excess flow to keep the output pressure and flow stable.

Figure 3(b) shows the energy release process, and the dotted arrow indicates the hydraulic oil flow circuit. At this time, the high-speed switching valves 41 and 43 are both closed, and the B port and the C port of the two-position three-way valve 71 are also kept open. At this time, the mass block continues to move under the action of inertia, and the hydraulic oil is sucked into the inertial device 6 from the low-pressure oil supply port 2 . At this time, because the load pressure p _L is higher than the oil supply pressure p _{T of} the low-pressure oil port, the mass block decelerates under the action of hydraulic thrust until the speed of the mass block drops to zero, and the mass block completely releases the stored kinetic energy and converts it into hydraulic pressure. able. The process mass performs deceleration motion, namely:

$<span\; class="notranslate">\; -</span>\mathrm{<span\; class="notranslate">\; m</span>}\stackrel{<span\; class="notranslate">\; \&Center\; Dot;</span>}{\mathrm{<span\; class="notranslate">\; v</span>}}<span\; class="notranslate">\; =</span><span\; class="notranslate">\; (</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; S</span>}}<span\; class="notranslate">\; -</span>{\mathrm{<span\; class="notranslate">\; p</span>}}_{\mathrm{<span\; class="notranslate">\; L</span>}}<span\; class="notranslate">\; )</span>\mathrm{<span\; class="notranslate">\; S</span>}$

During this process, due to the continuous decrease of the speed of the mass block, the flow discharged from the inertial device decreases. At this time, the accumulator 8 discharges the absorbed hydraulic oil to make up for the shortage of output flow, so as to keep the output pressure and flow stable.

Figure 4 shows the control signal of the hydraulic energy-saving controller valve, where k is the duty cycle and T ₀ is the time period. As shown in Figure 1, the signals 31, 32, 33 and 34 are the control signals of the high-speed on-off valve 4. When the signal amplitude is 1, the high-speed on-off valve 4 is in the open state, and when the amplitude is 0, it is in the closed state. Signals 35 and 36 are the control signals of the two-position three-way valve 7. When the signal amplitude is 1, the B port and the C port of the two-position three-way valve 7 are connected. When the amplitude is 0, the two-position three-way valve 7 is connected. Port A is connected to port C. Under the control of the signal shown in Fig. 4, the valve in the hydraulic energy-saving controller repeats the working process shown in Fig. 3 . That is, the complete working process of the energy-saving controller is as follows: under the control of the signal in Figure 4, the amplitude of the control signal 31 is 1 at first, the high-speed on-off valve 41 is opened, and the other high-speed on-off valves are in the closed state. At this time, the first inertial device 61 executes the In the working process shown in Figure 3(a), when the amplitude of the control signal 31 is zero, the high-speed switching valve 42 is closed, and the first inertial device 61 executes the working process shown in Figure 3(b). Then the amplitude of the control signal 32 is 1, the high-speed on-off valve 42 is opened, and the other high-speed on-off valves are in the closed state, and the second inertial device 62 executes the work process shown in Figure 3 (a). When the amplitude of the control signal 32 is zero, the high-speed on-off valve The on-off valve 42 is closed, and the second inertial device 62 executes the work process shown in FIG. 3( b ). When performing these four work processes, ports B and C of the two-position three-way reversing valves 71 and 72 are connected. When the amplitude of the control signal 33 is 1 at first, the high-speed on-off valve 43 is opened, and the other high-speed on-off valves are in the closed state. At this time, the first inertial device 61 performs the work process shown in FIG. Contrary to what is shown in (a), the A port and the C port of the two-position three-way reversing valve 71 are connected. When the amplitude of the control signal 33 is zero, the high-speed switching valve 43 is closed, and the first inertial device 61 performs the operation shown in Fig. 3 ( In the working process shown in b), the running direction of the mass block is also opposite to that shown in FIG. When the amplitude of the control signal 34 is 1 at first, the high-speed on-off valve 44 is opened, and the other high-speed on-off valves are in the closed state. At this time, the second inertial device 62 performs the work process shown in FIG. Contrary to what is shown in (a), the port A and port C of the two-position three-way reversing valve 72 are connected. When the amplitude of the control signal 34 is zero, the high-speed switching valve 44 is closed, and the first inertial device 62 performs the operation shown in Fig. 3 ( In the working process shown in b), the running direction of the mass block is also opposite to that shown in FIG. Through the cyclic execution of the above work projects, the oil outlet continuously outputs stable pressure and flow.

When the output flow is kept constant, the output pressure can be adjusted by adjusting the duty ratio k. The output pressure p _L can be expressed as:

p _L ＝p _T +(p _S -p _T )k

Similarly, to keep the output pressure constant, the output flow can be adjusted by adjusting the duty cycle k. Figure 5 shows the output pressure and flow curves of a hydraulic energy-saving controller under different duty ratios k.

Therefore, the utility model can match the output pressure and flow with the load pressure and flow by adjusting the duty cycle, that is, by controlling the time of the high-pressure oil port and the low-pressure oil supply port, so that the total input energy is always consistent with the load required Energy matching, and finally achieve the purpose of energy saving and high efficiency.

Claims (8)

1. a hydraulic energy-saving controller, comprise high pressure filler opening, low pressure oil filler opening and the oil outlet be communicated with final controlling element, it is characterized in that, described high pressure filler opening is communicated with final controlling element by energy conserving system, described energy conserving system comprises the first high-speed switch valve, second high-speed switch valve, selector valve and inertia device, described inertia device comprises mass block, the bilateral symmetry of described mass block is provided with hydraulic piston, the end of the piston rod of described hydraulic piston is arranged on the both sides of described mass block, described high pressure filler opening is communicated with the rodless cavity of the second high-speed switch valve with the hydraulic piston at the two ends of inertia device with the first high-speed switch valve be arranged on pipeline respectively by pipeline, the rodless cavity of two described hydraulic pistons is connected with the filler opening A of selector valve and filler opening B respectively by oil circuit, the oil outlet C of described selector valve is communicated with final controlling element, and the oil circuit between the oil outlet C of selector valve and final controlling element is also parallel with accumulator, the rodless cavity of two hydraulic pistons of described inertia device is also communicated with low pressure filler opening.

2. hydraulic energy-saving controller according to claim 1, it is characterized in that: the oil circuit between the rodless cavity of two hydraulic pistons of described inertia device and the filler opening A of selector valve and filler opening B is separately installed with the first one-way valve preventing hydraulic oil from refluxing to inertia device, oil circuit between described selector valve and final controlling element is also provided with the second one-way valve preventing hydraulic oil from refluxing to oil outlet C, the oil circuit between the rodless cavity of two hydraulic pistons of described inertia device and low pressure filler opening is provided with the 3rd one-way valve preventing hydraulic oil from refluxing to low pressure filler opening.

3. hydraulic energy-saving controller according to claim 2, is characterized in that: comprise the described energy conserving system of two covers, and the oil outlet C of the selector valve of the described energy conserving system of two covers is communicated with.

4. hydraulic energy-saving controller according to claim 3, is characterized in that: described selector valve is two-bit triplet high speed selector valve.

5. according to the hydraulic energy-saving controller one of Claims 1-4 Suo Shu; it is characterized in that: described hydraulic piston is arranged on supporting frame and outer wrap has safety cover, and described hydraulic piston and described mass block opposing side are provided with the flexible block preventing collsion damage.

6. hydraulic energy-saving controller according to claim 5, is characterized in that: the cylinder barrel of described hydraulic piston is high voltage bearing high pressure straight tube.

7. hydraulic energy-saving controller according to claim 6, is characterized in that: the end cap of described hydraulic piston is fixed by screws in safety cover two ends, and is provided with resilient pad between described end cap and safety cover.

8. according to the hydraulic energy-saving controller one of Claims 1-4 Suo Shu, it is characterized in that: described high-speed switch valve and selector valve all adopt pwm signal as control signal.