An efficient hydraulic soft-switching variable pressure circuit based on a high-speed switching valve

Abstract

The present invention relates to a high-efficiency hydraulic soft-switch voltage conversion circuit based on a high-speed switching valve, comprising a main system and an auxiliary system. The main system comprises a motor inertia flywheel assembly A1, a high-speed switching valve B1, a hydraulically controlled one-way valve C1, and a one-way valve D1; the auxiliary system comprises a motor inertia flywheel A2, a high-speed switching valve B2, a hydraulically controlled one-way valve C2, and a one-way valve D2; the pump source output end is connected to the oil inlet of the motor inertia flywheel A1; the oil outlet of the motor inertia flywheel A1 is connected to the oil inlet of the motor inertia flywheel A2, the oil inlet of the high-speed switching valve B1, and the oil inlet of the one-way valve D1; the oil outlet of the motor inertia flywheel A2 is connected to the oil inlet of the high-speed switching valve B2 and the oil inlet of the one-way valve D2. The present invention has a reasonable design and realizes the zero-pressure opening and zero-pressure closing functions of the switching valve; the hydraulically controlled one-way valve is used as the basic medium to realize the four zero functions, eliminating the four overlapping areas caused by the opening and closing of the two high-speed switching valves in the system circuit, thereby improving the efficiency of the voltage conversion system.

Description

Technical field:

[0002] The present invention belongs to the technical field of switch hydraulics, and in particular relates to a high-efficiency hydraulic soft-switch voltage-changing circuit based on a high-speed switch valve. Background technology:

[0004] The theory of switching hydraulic power sources originates from the DC / DC conversion theory in power electronics technology. It is a hydraulic circuit that achieves pressure conversion based on a combination of high-speed switching valves, liquid capacitance, and liquid inductance. This device has the potential to provide high-efficiency and high-bandwidth pressure conversion. It utilizes the inherent characteristics of hydraulic components, such as the liquid inductance effect of slender tubes and the liquid capacitance effect of accumulators. In theory, this switching hydraulic system transformed from a DC / DC conversion system can achieve 100% pressure conversion efficiency. However, in practice, the high-speed switching valve, as the core component for achieving pressure conversion, has a delay time when it opens and closes. During this delay time, there is an overlapping area of pressure and flow, which makes it impossible for the switching hydraulic power source system to achieve 100% efficiency. Compared with the DC / DC conversion system, the pressure conversion efficiency of the switching hydraulic power source system is much lower.

[0005] To address the overlap losses of the switching hydraulic power source and improve the efficiency of the switching hydraulic power source system, researchers drew on soft switching technology from power electronics. In the circuit, soft switching relies primarily on three basic components: a capacitor, a diode, and an inductor connected in parallel across the switching tube. By leveraging the resonant effect of the capacitor and inductor, and using auxiliary switching tubes, efficiency is improved at different circuit duty cycles and frequencies. Existing hydraulic soft-switching technology is primarily represented by basic hydraulic soft-switching units with spring locking mechanisms and hydraulic soft-switching circuits designed based on circuit soft-switching circuits. The paper "Soft Switch Lock-Release Mechanism for a Switch-Mode Hydraulic Pump Circuit," published in the Journal of dynamic systems measurement and control-transactions of the ASME, proposes a spring locking mechanism that eliminates losses in the switch overlap zone by setting a spring stroke to cushion the pressure shock generated when a high-speed switch valve is closed and opened. Similarly, similar hydraulic soft-switching circuits, such as Chinese invention patent CN202110557022.8, disclose a hydraulic soft-switching transformer for achieving pressure rise and fall. This transformer, based on a four-switch circuit topology, utilizes a spring accumulator and one-way valves connected in parallel at both ends of the four switch valves to achieve zero-pressure closing and zero-flow opening, respectively, eliminating the switch overlap zone and improving system efficiency. While the feasibility of the soft-switching scheme has been verified through theoretical analysis, existing hydraulic soft-switching conversion schemes still have some shortcomings, primarily reflected in the following aspects:

[0006] (1) The hydraulic soft switch solution is a basic hydraulic soft switch unit represented by a spring locking mechanism. Under different working conditions, the limitations of using a spring as a hydraulic soft switch mechanism are: 1. The locking stroke is fixed, so the spring cannot completely or partially absorb the pressure shock when the switch valve is opened or closed under different working conditions, and the introduction of an oversized valve front cavity increases the energy loss of the valve at the moment of opening; 2. When the switch hydraulic source system is actuated, the actuation frequency of the valve is usually very good, and the response characteristics of the spring cannot keep up with the actuation frequency of the valve;

[0007] (2) The realization of soft switching in the circuit relies on the resonance process of capacitors and inductors, and this process can only be realized in a closed system. However, the hydraulic soft switching circuit designed in full accordance with the basic circuit of soft switching in the circuit ignores the characteristics that the hydraulic circuit is an open circuit and the circuit is a closed circuit. Theoretically, it can achieve the same function as the circuit soft switch, but in actual application, the oil tank does not provide reverse pressure, making it impossible to open the one-way valve connected in parallel at both ends of the switch valve. The one-way valve cannot divert the flow in the overlapping area loss to the oil tank, realizing the zero flow effect of the switch valve, and the circuit efficiency cannot be effectively improved;

[0008] (3) Similar to the circuit, since the overlap loss of the valve cannot be effectively eliminated by adjusting the voltage and changing the structure, the reference circuit eliminates the switch overlap area. In the hydraulic circuit, in order to achieve the soft switching effect, it is necessary to use external components to eliminate the switch overlap area loss; however, this method of introducing components from the outside will inevitably introduce new losses into the system. Summary of the invention:

[0010] The present invention aims to improve the problems existing in the above-mentioned prior art. That is, the technical problem to be solved by the present invention is to provide a high-efficiency hydraulic soft-switching voltage-converting circuit based on a high-speed switching valve.

[0011] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a high-efficiency hydraulic soft-switching voltage-converting circuit based on a high-speed switching valve, comprising a main system and an auxiliary system, wherein the main system comprises a motor inertia flywheel assembly A1, a high-speed switching valve B1, a hydraulically controlled one-way valve C1, and a one-way valve D1; the auxiliary system comprises a motor inertia flywheel A2, a high-speed switching valve B2, a hydraulically controlled one-way valve C2, and a one-way valve D2, the pump source output end is connected to the oil inlet of the motor inertia flywheel A1, and the oil outlet of the motor inertia flywheel A1 is respectively connected to the oil inlet of the motor inertia flywheel A2. , the oil inlet of the high-speed switching valve B1 and the oil inlet of the one-way valve D1; the oil outlet of the motor inertia flywheel A2 is connected to the oil inlet of the high-speed switching valve B2 and the oil inlet of the one-way valve D2, and the oil outlet of the high-speed switching valve B1 and the oil outlet of the high-speed switching valve B2 are connected to the oil tank; the hydraulically controlled one-way valve C1 is connected in parallel at both ends of the high-speed switching valve B1, and the hydraulically controlled one-way valve C2 is connected in parallel at both ends of the high-speed switching valve B2, the control oil port end of the hydraulically controlled one-way valve C1 is connected to the oil inlet of the high-speed switching valve B2, and the control oil port end of the hydraulically controlled one-way valve C2 is connected to the oil inlet of the high-speed switching valve B1.

[0012] Furthermore, the opening sequence of the high-speed switching valve B1 and the high-speed switching valve B2 must satisfy that the high-speed switching valve B2 opens before the high-speed switching valve B1 within a single cycle, and there is an overlapping opening time between the high-speed switching valve B1 and the high-speed switching valve B2.

[0013] Furthermore, by changing the time when the high-speed switching valve B1 and the high-speed switching valve B2 are simultaneously opened in the current cycle, the closing time of the high-speed switching valve B1 and the high-speed switching valve B2 in their respective cycles can be controlled, thereby controlling the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 to open before the high-speed switching valve B1 is closed, and the flow in the delayed overlapping area of the high-speed switching valve is diverted to the oil tank through the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2, thereby realizing the zero flow effect of the high-speed switching valve.

[0014] Furthermore, valve core springs are provided inside the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 to ensure that the pressure shock is buffered when the valve pressure suddenly changes, so that the pressure in the delayed overlapping area of the high-speed switching valve B1 and the high-speed switching valve B2 is zero, thereby realizing the zero-pressure effect of the high-speed switching valve.

[0015] Another technical solution adopted by the present invention is: a working method of a high-efficiency hydraulic soft-switch transformer circuit based on a high-speed switching valve. The way to improve the efficiency of the hydraulic transformer is divided into zero pressure action and zero flow action, which can be specifically divided into four stages according to zero pressure opening, zero pressure closing, zero flow opening and zero flow closing: (1) Realizing the zero-pressure opening of the high-speed switching valve B1: the valve core spring of the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switching valve B1 buffers the pressure impact when the high-speed switching valve B1 is opened, so that the pressure in the overlapping area loss generated when the high-speed switching valve B1 is opened is zero; (2) Realizing the zero-pressure closing of the high-speed switching valve B2 .... The valve core spring of the hydraulically controlled one-way valve C2 at both ends of the shut-off valve B2 buffers the pressure impact when the high-speed switch valve B2 is shut off, so that the pressure in the overlapping area loss generated when the high-speed switch valve B2 is shut off is zero; (3) Achieve zero flow shut-off of the high-speed switch valve B1: the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switch valve B1 is opened before the high-speed switch valve B1 is shut off, so that the flow in the overlapping area loss generated when the high-speed switch valve B1 is shut off is zero; (4) Achieve zero flow opening of the high-speed switch valve B2: the hydraulically controlled one-way valve C2 connected in parallel at both ends of the high-speed switch valve B2 is opened before the high-speed switch valve B2 is opened, so that the flow in the overlapping area loss when the high-speed switch valve B2 is opened is zero.

[0016] Furthermore, by setting the duty cycle of the high-speed switching valve, the timing control of the hydraulically controlled one-way valve can be achieved, thereby realizing the four basic modes of hydraulic soft switching: zero pressure opening, zero pressure closing, zero flow opening, and zero flow closing. The following steps are included:

[0017] Step S1: During the delayed opening of the high-speed on-off valve B1 and the delayed closing of the high-speed on-off valve B2, the valve core spring of the hydraulically controlled one-way valve C2 absorbs the pressure shock when the high-speed on-off valve B1 is opened, thereby achieving zero-pressure opening of the high-speed on-off valve B1 and controlled opening of the hydraulically controlled one-way valve C1;

[0018] Step S2: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 accelerates to store energy, the motor inertia flywheel A2 decelerates, the hydraulically controlled one-way valve C1 remains open, and the one-way valve D2 opens;

[0019] Step S3: During the period when the high-speed on-off valve B1 is delayed in closing and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 continues to decelerate, the hydraulically controlled one-way valve C1 remains open, achieving zero-flow shutoff of the high-speed on-off valve B1, and the hydraulically controlled one-way valve C2 begins to open;

[0020] Step S4: While the high-speed on-off valve B1 and the high-speed on-off valve B2 are closed, the motor inertia flywheel A1 is accelerated, the motor inertia flywheel A2 is decelerated, and the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 are opened.

[0021] Step S5: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 is delayed in opening, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 begins to accelerate, the hydraulically controlled one-way valve C2 remains open, achieving zero-flow opening of the high-speed on-off valve B2, and the hydraulically controlled one-way valve C1 begins to close;

[0022] Step S6: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 continues to decelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C2 remains open, and the hydraulically controlled one-way valve C1 remains closed;

[0023] Step S7: During the period when the high-speed on-off valve B1 is delayed in opening and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 begins to accelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C1 remains closed, and the hydraulically controlled one-way valve C2 begins to close;

[0024] Step S8: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 is delayed in closing, the motor inertia flywheel A1 continues to accelerate, and the motor inertia flywheel A2 begins to decelerate. The valve core spring of the hydraulically controlled one-way valve C1 buffers the pressure shock caused by the closing of the high-speed on-off valve B2, thereby achieving zero-pressure opening of the high-speed on-off valve B2. The hydraulically controlled one-way valve C2 remains closed, and a complete working cycle ends.

[0025] Furthermore, by setting the duty cycle of the high-speed switching valve B2, the high-speed switching valve B1 can eliminate the switching overlap loss at any duty cycle and any switching frequency, and realize the four soft switching functions of zero pressure opening, zero pressure closing, zero flow opening and zero flow closing.

[0026] Compared with the prior art, the present invention has the following effects:

[0027] (1) The hydraulic control one-way valve is used as the basic element to realize the hydraulic soft switch. The hydraulic soft switch circuit designed by comparison with the circuit ignores the difference between the DC / DC conversion circuit being a closed circuit and the switch hydraulic source system being an open circuit. As a result, the oil inlet pressure of the one-way valve connected in parallel at both ends of the high-speed switch valve in the hydraulic soft switch circuit directly compared with the design is always lower than the oil outlet pressure, resulting in the one-way valve being unable to open and unable to achieve zero flow effect. The introduction of the accumulator in front of the valve will increase the volume in front of the valve, increase the loss in front of the valve and make the efficiency low. With the help of the controlled opening property of the hydraulic control one-way valve and the property of the rising pressure in front of the valve when the high-speed switch valve is closed, the opening and closing of the hydraulic control one-way valve is controlled to achieve zero flow effect. The spring accumulator composed of the valve core spring of the hydraulic control one-way valve and the hydraulic control port not only reduces the volume in front of the valve, but also absorbs the pressure shock generated when the valve is opened and closed, thereby achieving the zero pressure opening and closing effect of the switch valve.

[0028] (2) An auxiliary system consisting of a motor inertia flywheel A2, a high-speed switch valve B2 and a one-way valve D3 is introduced into the original boost circuit. The purpose of introducing the auxiliary system is to realize the control of the hydraulically controlled one-way valve C1. The auxiliary system is powered by the main system. The energy provided by the main system is temporarily absorbed by the motor inertia flywheel A2. The energy stored in the motor inertia flywheel A2 is released to the load through the one-way valve D3 when the high-speed switch valve B2 is turned off. At the same time, the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switch valve B1 is opened to realize the zero-flow shutoff of the high-speed switch valve B1.

[0029] (3) Adding an auxiliary commutation system controlled by a high-speed switching valve B2 to the original system means introducing new losses into the system. To address the switching overlap losses caused by the high-speed switching valve B2 introduced into the auxiliary system, a hydraulically controlled one-way valve C2 controlled by a high-speed switching valve B1 is connected in parallel at both ends of the high-speed switching valve B2, and an actuation sequence is designed to achieve zero flow shutoff of the high-speed switching valve B1 and zero flow opening of the high-speed switching valve B2; the hydraulically controlled one-way valves connected in parallel at both ends of the high-speed switching valve are controlled to open when the high-speed switching valve is shut off. By setting the duty cycle of the high-speed switching valve B2, the zero pressure effect and zero flow effect in the switching delay time overlap loss of the high-speed switching valve B1 and the high-speed switching valve B2 at different duty cycles and different frequencies can be achieved. Description of the drawings:

[0031] Figure 1 1 is a schematic diagram of the circuit composition of an embodiment of the present invention;

[0032] Figure 2 This is a schematic diagram of the working principle of an embodiment of the present invention. Figure 1 ;

[0033] Figure 3 This is a schematic diagram of the working principle of an embodiment of the present invention. Figure 2 ;

[0034] Figure 4 This is a schematic diagram of the working principle of an embodiment of the present invention. Figure 3 ;

[0035] Figure 5 This is a schematic diagram of the working principle of an embodiment of the present invention. Figure 4 .

[0036] In the picture:

[0037] A1-motor inertia flywheel A1; A2-motor inertia flywheel A2; B1-high-speed switching valve B1; B2-high-speed switching valve B2; C1-hydraulic control one-way valve C1; C2-hydraulic control one-way valve C2; D1-one-way valve D1; D2-one-way valve D2; E-gas-charged accumulator; F-load F; Ch1-valve upstream chamber of high-speed switching valve B1; Ch2-valve upstream chamber of high-speed switching valve B2; Ps-pump source pressure; PL-tank pressure. Specific implementation method:

[0039] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0040] In the description of the present invention, it should be understood that the terms "longitudinal", "transverse", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside" and the like to indicate orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present invention, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the present invention.

[0041] The present invention discloses a high-efficiency hydraulic soft-switching transformer circuit based on a high-speed switching valve. The specific implementation method is to introduce an auxiliary commutation system into the system. The basic concept of auxiliary commutation comes from the zero-current conversion technology in power electronics technology. The zero-current conversion technology is a soft switching scheme in the circuit that reduces the switching loss of the DC / DC converter. Its core idea is to reduce the current in the switching process to zero. By introducing a closed loop circuit consisting of a capacitive element, an inductive element, an anti-parallel diode and an auxiliary switch, a resonance process is introduced before and after the switch. The auxiliary switch tube is used to control the anti-parallel diodes at both ends of the switch tube to conduct before and after the switch, so that the switching process of the switch tube is in a short-circuit state. At this time, no current passes through the switch tube, thereby eliminating the overlapping area of the switch tube. The advantage of this zero-current conversion technology existing in power electronics technology is that the added inductive element has the function of suppressing current spikes and reducing the switching loss of the externally introduced switch tube. At the same time, the switching loss of the main circuit switch tube is also effectively reduced, and the soft switching effect is further exerted. Inspired by the zero-current conversion technology in power electronics technology, the core idea of the auxiliary commutation system is to reduce the current to zero during the switching process. The goal is to reduce the flow rate during the high-speed on-off valve switching process to zero. This has the advantage of eliminating the pressure fluctuations associated with high-speed on-off valve switching and eliminating switching losses by simply eliminating the flow rate during the switching process. However, to achieve auxiliary commutation, an auxiliary commutation system consisting of a fluid-sensing element, an auxiliary high-speed on-off valve, and a hydraulically controlled check valve must be introduced into the switching transformer system. The fluid-sensing element in the auxiliary commutation system suppresses flow spikes, and its stable pressure output effectively reduces the flow spikes generated during the switching of the series-connected on-off valve. The auxiliary high-speed on-off valve controls the opening timing of the hydraulically controlled check valve, causing it to open before or after the main circuit high-speed on-off valve. This preemptively diverts the flow passing through the on-off valve switching process to the tank, eliminating flow during the switching process and thus eliminating switching losses in the main circuit high-speed on-off valve. Although the fluid-sensing element effectively suppresses the flow spikes generated during the switching of the auxiliary circuit high-speed on-off valve, flow still passes through the auxiliary circuit high-speed on-off valve during the switching process, and the switching overlap losses of the auxiliary circuit high-speed on-off valve are not completely eliminated. Compared with electrical circuits, due to the characteristics of the open circuit of the hydraulic system, the switch valves connected in series with the inductive element are all independent flow branches. There is no need to consider the impact of the main circuit on the auxiliary system circuit in the closed-loop system. This also creates conditions for eliminating the unnecessary switching losses of the auxiliary high-speed switch valve. Therefore, in order to solve the loss problem caused by the high-speed switch valve introduced in the auxiliary circuit, adhering to the idea of auxiliary commutation, a hydraulically controlled one-way valve is connected in parallel at both ends of the auxiliary circuit high-speed switch valve. This hydraulically controlled one-way valve is controlled by the hydraulic flow branch composed of the liquid sensing element and the high-speed switch valve in the main circuit system. The hydraulically controlled one-way valve is opened before and after the auxiliary switch valve is switched, thereby diverting the flow to the oil tank in advance, achieving the purpose of eliminating the loss in the switching overlap area.

[0042] like Figure 1 As shown, the high-efficiency hydraulic soft-switching voltage conversion circuit based on the high-speed switching valve includes a main system and an auxiliary system. The main system includes a motor inertia flywheel combination A1, a high-speed switching valve B1, a hydraulically controlled one-way valve C1, and a one-way valve D1; the auxiliary system includes a motor inertia flywheel A2, a high-speed switching valve B2, a hydraulically controlled one-way valve C2, and a one-way valve D2. The pump source output end is connected to the oil inlet of the motor inertia flywheel A1, and the oil outlet of the motor inertia flywheel A1 is connected to the oil inlet of the motor inertia flywheel A2 and the inlet of the high-speed switching valve B1 respectively. The oil port and the oil inlet of the one-way valve D1; the oil outlet of the motor inertia flywheel A2 is connected to the oil inlet of the high-speed switching valve B2 and the oil inlet of the one-way valve D2, and the oil outlet of the high-speed switching valve B1 and the oil outlet of the high-speed switching valve B2 are connected to the oil tank; the hydraulically controlled one-way valve C1 is connected in parallel at both ends of the high-speed switching valve B1, and the hydraulically controlled one-way valve C2 is connected in parallel at both ends of the high-speed switching valve B2, the control oil port end of the hydraulically controlled one-way valve C1 is connected to the oil inlet of the high-speed switching valve B2, and the control oil port end of the hydraulically controlled one-way valve C2 is connected to the oil inlet of the high-speed switching valve B1.

[0043] In this embodiment, the opening timing of the high-speed switching valve B1 and the high-speed switching valve B2 must satisfy that the high-speed switching valve B2 opens before the high-speed switching valve B1 within a single cycle, and there is a certain opening overlap time between the two.

[0044] In this embodiment, a switch valve overlap zone loss due to overlapping pressure and flow is generated during the delay time between the opening and closing of the high-speed switch valves. By utilizing the characteristic that the hydraulically controlled one-way valve opens when the high-speed switch valves B1 and B2 are closed, and by changing the time when the high-speed switch valves B1 and B2 are simultaneously opened in the current cycle, the closing time of the high-speed switch valves B1 and B2 in their respective cycles can be controlled, thereby controlling the hydraulically controlled one-way valves C1 and C2 to open before the high-speed switch valve B1 is closed, and diverting the flow in the delayed overlapping zone of the high-speed switch valves to the oil tank through the hydraulically controlled one-way valves C1 and C2, thereby achieving the zero-flow effect of the high-speed switch valves.

[0045] In this embodiment, both hydraulically controlled check valves C1 and C2 are equipped with spool springs to cushion sudden pressure shocks. This ensures that the pressure within the delayed overlap region of high-speed on / off valves B1 and B2 is zero, thus achieving zero-pressure operation for the high-speed on / off valves. By adjusting the duty cycle of high-speed on / off valve B2, high-speed on / off valve B1 can eliminate switching overlap losses at any duty cycle and switching frequency, achieving four soft-switching functions: zero-pressure on, zero-pressure off, zero-flow on, and zero-flow off.

[0046] In this embodiment, the hydraulically controlled check valve is the core component for implementing the four basic hydraulic soft switching modes. The valve core spring of the hydraulically controlled check valve absorbs the pressure shock generated during the opening and closing delay time of the high-speed switching valve, achieving a zero-pressure effect. The opening time of the hydraulically controlled check valve within a single cycle of the high-speed switching valve is controlled by the actuation timing relationship of the high-speed switching valve, achieving a zero-flow effect. By introducing an auxiliary system into the main system (i.e., the basic boost circuit) to control the hydraulically controlled check valve, the auxiliary system does not dissipate system energy in the circuit, but instead stores energy through an inertial flywheel. The stored energy is then used to control the opening and closing of the hydraulically controlled check valve, retransmitting the kinetic energy stored in the inertial flywheel to the load. Therefore, the load not only receives inertial flywheel energy from the main system, but also receives inertial flywheel energy transmitted by the auxiliary system. This results in higher load pressure and greater flow rate than without the auxiliary system.

[0047] In this embodiment, the working method of the high-efficiency hydraulic soft-switch transformer circuit based on the high-speed switching valve is as follows: the way to improve the efficiency of the hydraulic transformer is divided into zero pressure effect and zero flow effect, which can be specifically divided into four stages according to zero pressure opening, zero pressure closing, zero flow opening and zero flow closing: (1) realizing zero pressure opening of the high-speed switching valve B1: the valve core spring of the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switching valve B1 buffers the pressure impact when the high-speed switching valve B1 is opened, so that the pressure in the overlapping area loss generated when the high-speed switching valve B1 is opened is zero; (2) realizing zero pressure closing of the high-speed switching valve B2: the valve core spring of the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switching valve B2 buffers the pressure impact when the high-speed switching valve B1 is opened, so that the pressure in the overlapping area loss generated when the high-speed switching valve B1 is opened is zero; The valve core spring of the hydraulically controlled one-way valve C2 at the end buffers the pressure impact when the high-speed switch valve B2 is closed, so that the pressure in the overlapping area loss generated when the high-speed switch valve B2 is closed is zero; (3) Realize the zero flow shutdown of the high-speed switch valve B1: the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed switch valve B1 is opened before the high-speed switch valve B1 is closed, so that the flow in the overlapping area loss generated when the high-speed switch valve B1 is closed is zero; (4) Realize the zero flow opening of the high-speed switch valve B2: the hydraulically controlled one-way valve C2 connected in parallel at both ends of the high-speed switch valve B2 is opened before the high-speed switch valve B2 is opened, so that the flow in the overlapping area loss when the high-speed switch valve B2 is opened is zero. The valve core spring of the hydraulically controlled one-way valve connected in parallel at both ends of the high-speed switching valve is used to buffer the pressure impact generated when the switching valve is opened and closed, thereby realizing the zero-pressure opening and zero-pressure closing effects of the switching valve; the hydraulically controlled one-way valve is used as the basic medium to realize the four zero effects, eliminating the four overlapping areas caused by the opening and closing of the two high-speed switching valves in the system loop, thereby improving the efficiency of the transformer system.

[0048] In this embodiment, by setting the duty cycle of the two high-speed switching valves, the timing control of the hydraulically controlled one-way valve can be achieved, thereby eliminating the loss in the switching overlap area, and further realizing the four basic modes of hydraulic soft switching: zero pressure opening, zero pressure closing, zero flow opening, and zero flow closing. The specific steps include:

[0049] Step S1: During the delayed opening of the high-speed on-off valve B1 and the delayed closing of the high-speed on-off valve B2, the valve core spring of the hydraulically controlled one-way valve C2 absorbs the pressure shock when the high-speed on-off valve B1 is opened, thereby achieving zero-pressure opening of the high-speed on-off valve B1 and controlled opening of the hydraulically controlled one-way valve C1;

[0050] Step S2: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 accelerates to store energy, the motor inertia flywheel A2 decelerates, the hydraulically controlled one-way valve C1 remains open, and the one-way valve D2 opens;

[0051] Step S3: During the period when the high-speed on-off valve B1 is delayed in closing and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 continues to decelerate, the hydraulically controlled one-way valve C1 remains open, achieving zero-flow shutoff of the high-speed on-off valve B1, and the hydraulically controlled one-way valve C2 begins to open;

[0052] Step S4: While the high-speed on-off valve B1 and the high-speed on-off valve B2 are closed, the motor inertia flywheel A1 is accelerated, the motor inertia flywheel A2 is decelerated, and the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 are opened.

[0053] Step S5: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 is delayed in opening, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 begins to accelerate, the hydraulically controlled one-way valve C2 remains open, achieving zero-flow opening of the high-speed on-off valve B2, and the hydraulically controlled one-way valve C1 begins to close;

[0054] Step S6: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 continues to decelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C2 remains open, and the hydraulically controlled one-way valve C1 remains closed;

[0055] Step S7: During the period when the high-speed on-off valve B1 is delayed in opening and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 begins to accelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C1 remains closed, and the hydraulically controlled one-way valve C2 begins to close;

[0056] Step S8: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 is delayed in closing, the motor inertia flywheel A1 continues to accelerate, and the motor inertia flywheel A2 begins to decelerate. The valve core spring of the hydraulically controlled one-way valve C1 buffers the pressure shock caused by the closing of the high-speed on-off valve B2, thereby achieving zero-pressure opening of the high-speed on-off valve B2. The hydraulically controlled one-way valve C2 remains closed, and a complete working cycle ends.

[0057] In a complete working cycle, the motor flywheels of the main and auxiliary systems undergo acceleration and deceleration processes. The motor flywheels suppress the sudden pressure changes in the system in a very short time. By storing energy in the motor flywheels, the load energy is transferred and the hydraulically controlled one-way valve is controlled within one working cycle.

[0058] In this embodiment, by setting the duty cycle of the high-speed switching valve B2, the high-speed switching valve B1 can eliminate the switching overlap zone loss at any duty cycle and any switching frequency, and realize the four soft switching functions of zero pressure opening, zero pressure closing, zero flow opening and zero flow closing.

[0059] Figures 2 to 5 The figure shows the specific working process of the embodiment of the present invention. By setting the duty cycle of the high-speed switching valve B2, four methods of eliminating the switching overlap zone loss of the high-speed switching valve B1 at any frequency and any duty cycle are realized.

[0060] Specific implementation process: High-speed on-off valve B1 and high-speed on-off valve B2 are alternately actuated in one cycle, so the original working cycle is divided into four stages and four time segments. , , , , :

[0061] like Figure 2 As shown: During the time period, the high-speed on-off valve B1 is in the open state, and the high-speed on-off valve B2 is in the closed state. The motor inertia flywheel A1 accelerates to store energy, and the hydraulically controlled one-way valve C1 is controlled to open; During the period from the moment the high-speed on-off valve B2 is completely closed, the small spring accumulator composed of the control chamber of the hydraulically controlled one-way valve C1 and the valve core spring plays a role, realizing the zero-pressure shutdown of the auxiliary on-off valve.

[0062] like Figure 3 As shown: During this time period, the high-speed switching valve B1 and the high-speed switching valve B2 are in the closed state. From the moment the high-speed on-off valve B1 is completely closed, the hydraulically controlled one-way valve C1 remains open, diverting the flow that was originally going to pass through the main on-off valve to the oil tank, thereby achieving zero-flow shutdown of the high-speed on-off valve B1. During this period, the control port of the hydraulically controlled one-way valve C2 loses pressure and cannot be opened. The one-way valve D2 is controlled to open, and the flow is supplied to the load.

[0063] like Figure 4 As shown: During this time period, the high-speed switch valve B1 is in the closed state, and the high-speed switch valve B2 is in the open state. The motor inertia flywheel A1 releases energy to the load and the inertia flywheel A2. During the period from the moment the high-speed switch valve B2 is completely closed, the hydraulically controlled one-way valve C1 is closed and the hydraulically controlled one-way valve C2 is controlled to open, diverting the flow that was originally going to pass through the high-speed switch valve B1 to the oil tank, thereby achieving zero-flow opening of the high-speed switch valve B2.

[0064] like Figure 5 As shown: During this time period, the high-speed on-off valve B1 and the high-speed on-off valve B2 are in the open state. The inertial flywheel A1 accelerates to store energy, and the high-speed on-off valve B2 maintains a constant speed. During the previous time period, the small spring accumulator composed of the hydraulically controlled one-way valve C2 cavity and the valve core spring plays a role. During the period when the high-speed on-off valve B1 is fully open, the pressure in front of the valve is balanced by the valve core spring of the hydraulically controlled one-way valve C2, realizing zero-pressure opening of the main on-off valve.

[0065] If the present invention discloses or involves components or structures that are fixedly connected to each other, then, unless otherwise stated, the fixed connection can be understood as: a detachable fixed connection (for example, connection using bolts or screws), and can also be understood as: a non-detachable fixed connection (for example, riveting, welding). Of course, the mutual fixed connection can also be replaced by an integrated structure (for example, manufactured by integral molding using a casting process) (except where it is obviously not possible to use an integrated molding process).

[0066] In addition, unless otherwise stated, the terms used in any technical solution disclosed in the present invention to express positional relationships or shapes include states or shapes that are approximate, similar, or close thereto.

[0067] Any component provided by the present invention may be assembled from multiple separate components, or may be a separate component manufactured by an integral molding process.

[0068] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to preferred embodiments, ordinary technicians in the field should understand that the specific implementation methods of the present invention can still be modified or some technical features can be replaced by equivalents without departing from the spirit of the technical solutions of the present invention. They should all be included in the scope of the technical solutions claimed for protection by the present invention.

Claims

1. A high-efficiency hydraulic soft-switching voltage conversion circuit based on a high-speed switching valve, characterized by: It includes a main system and an auxiliary system. The main system includes a motor flywheel assembly A1, a high-speed switch valve B1, a hydraulically controlled one-way valve C1, and a one-way valve D1. The auxiliary system includes a motor flywheel A2, a high-speed switch valve B2, a hydraulically controlled one-way valve C2, and a one-way valve D2. The pump source output end is connected to the oil inlet of the motor flywheel A1, and the oil outlet of the motor flywheel A1 is connected to the oil inlet of the motor flywheel A2, the oil inlet of the high-speed switch valve B1, and the oil inlet of the one-way valve D1. The oil outlet of the motor inertia flywheel A2 is connected to the oil inlet of the high-speed switch valve B2 and the oil inlet of the one-way valve D2, and the oil outlet of the high-speed switch valve B1 and the oil outlet of the high-speed switch valve B2 are connected to the oil tank; the hydraulically controlled one-way valve C1 is connected in parallel at both ends of the high-speed switch valve B1, and the hydraulically controlled one-way valve C2 is connected in parallel at both ends of the high-speed switch valve B2. The control oil port end of the hydraulically controlled one-way valve C1 is connected to the oil inlet of the high-speed switch valve B2, and the control oil port end of the hydraulically controlled one-way valve C2 is connected to the oil inlet of the high-speed switch valve B1; The opening sequence of the high-speed on-off valve B1 and the high-speed on-off valve B2 must satisfy that the high-speed on-off valve B2 opens before the high-speed on-off valve B1 within a single cycle, and there is an overlap in the opening time of the two valves. By changing the time when the high-speed on-off valve B1 and the high-speed on-off valve B2 are simultaneously opened in the current cycle, the off time of the high-speed on-off valve B1 and the high-speed on-off valve B2 in their respective cycles can be controlled, thereby controlling the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 to open before the high-speed on-off valve B1 is closed. The flow in the delayed overlapping area of the high-speed on-off valve is diverted to the oil tank through the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2, thereby realizing the zero flow effect of the high-speed on-off valve.

2. The high-efficiency hydraulic soft-switching voltage conversion circuit based on a high-speed switching valve according to claim 1 is characterized in that: Both the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 are provided with valve core springs to buffer the pressure shock when the valve pressure suddenly changes, so that the pressure in the delayed overlapping area of the high-speed switching valve B1 and the high-speed switching valve B2 is zero, thereby realizing the zero-pressure effect of the high-speed switching valve.

3. A method for operating a high-efficiency hydraulic soft-switching voltage conversion circuit based on a high-speed switching valve according to any one of claims 1 to 2, characterized in that: The methods to improve the efficiency of hydraulic transformers are divided into zero pressure action and zero flow action, which can be specifically divided into four stages: zero pressure opening, zero pressure shutoff, zero flow opening and zero flow shutoff: (1) Realize zero pressure opening of high-speed switch valve B1: The valve core spring of the hydraulic control one-way valve C1 connected in parallel at both ends of the high-speed switch valve B1 buffers the pressure impact when the high-speed switch valve B1 is opened, so that the pressure in the overlapping area loss generated when the high-speed switch valve B1 is opened is zero; (2) Realize zero pressure shutoff of high-speed switch valve B2: The valve core spring of the hydraulic control one-way valve C2 connected in parallel at both ends of the high-speed switch valve B2 is at high pressure. When the high-speed on-off valve B2 is closed, the pressure shock during the closing is buffered, so that the pressure in the overlapping area loss generated when the high-speed on-off valve B2 is closed is zero; (3) to achieve zero flow closing of the high-speed on-off valve B1: the hydraulically controlled one-way valve C1 connected in parallel at both ends of the high-speed on-off valve B1 is opened before the high-speed on-off valve B1 is closed, so that the flow in the overlapping area loss generated when the high-speed on-off valve B1 is closed is zero; (4) to achieve zero flow opening of the high-speed on-off valve B2: the hydraulically controlled one-way valve C2 connected in parallel at both ends of the high-speed on-off valve B2 is opened before the high-speed on-off valve B2 is opened, so that the flow in the overlapping area loss when the high-speed on-off valve B2 is opened is zero.

4. The method for operating a high-efficiency hydraulic soft-switching voltage conversion circuit based on a high-speed switching valve according to claim 3, characterized in that: By setting the duty cycle of the high-speed switching valve, the timing control of the hydraulically controlled check valve can be achieved, thereby realizing the four basic modes of hydraulic soft switching: zero pressure opening, zero pressure closing, zero flow opening, and zero flow closing. The following steps are included: Step S1: During the delayed opening of the high-speed on-off valve B1 and the delayed closing of the high-speed on-off valve B2, the valve core spring of the hydraulically controlled one-way valve C2 absorbs the pressure shock when the high-speed on-off valve B1 is opened, thereby achieving zero-pressure opening of the high-speed on-off valve B1 and controlled opening of the hydraulically controlled one-way valve C1; Step S2: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 accelerates to store energy, the motor inertia flywheel A2 decelerates, the hydraulically controlled one-way valve C1 remains open, and the one-way valve D2 opens; Step S3: During the period when the high-speed on-off valve B1 is delayed in closing and the high-speed on-off valve B2 remains closed, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 continues to decelerate, the hydraulically controlled one-way valve C1 remains open, achieving zero-flow shutoff of the high-speed on-off valve B1, and the hydraulically controlled one-way valve C2 begins to open; Step S4: While the high-speed on-off valve B1 and the high-speed on-off valve B2 are closed, the motor inertia flywheel A1 is accelerated, the motor inertia flywheel A2 is decelerated, and the hydraulically controlled one-way valve C1 and the hydraulically controlled one-way valve C2 are opened. Step S5: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 is delayed in opening, the motor inertia flywheel A1 begins to decelerate, the motor inertia flywheel A2 begins to accelerate, the hydraulically controlled one-way valve C2 remains open, achieving zero-flow opening of the high-speed on-off valve B2, and the hydraulically controlled one-way valve C1 begins to close; Step S6: While the high-speed on-off valve B1 remains closed and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 continues to decelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C2 remains open, and the hydraulically controlled one-way valve C1 remains closed; Step S7: During the period when the high-speed on-off valve B1 is delayed in opening and the high-speed on-off valve B2 remains open, the motor inertia flywheel A1 begins to accelerate, the motor inertia flywheel A2 continues to accelerate, the hydraulically controlled one-way valve C1 remains closed, and the hydraulically controlled one-way valve C2 begins to close; Step S8: While the high-speed on-off valve B1 remains open and the high-speed on-off valve B2 is delayed in closing, the motor inertia flywheel A1 continues to accelerate, and the motor inertia flywheel A2 begins to decelerate. The valve core spring of the hydraulically controlled one-way valve C1 buffers the pressure shock caused by the closing of the high-speed on-off valve B2, thereby achieving zero-pressure opening of the high-speed on-off valve B2. The hydraulically controlled one-way valve C2 remains closed, and a complete working cycle ends.

5. The method for operating a high-efficiency hydraulic soft-switching voltage conversion circuit based on a high-speed switching valve according to claim 4, characterized in that: By setting the duty cycle of the high-speed switching valve B2, the high-speed switching valve B1 can eliminate the switching overlap loss at any duty cycle and any switching frequency, and realize the four soft switching functions of zero pressure opening, zero pressure closing, zero flow opening and zero flow closing.

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