Digital valve pilot high-temperature fluid proportioning valve and control method

Abstract

The invention belongs to the technical field of special proportional regulating valves, and particularly relates to a digital valve pilot high-temperature fluid proportional regulating valve and a control method.The digital valve pilot high-temperature fluid proportional regulating valve comprises a valve body, a valve element, an array valve set and a control oil way, and a pilot valve cavity and a main valve cavity are formed in the valve body; a piston is arranged at the end, extending into the pilot valve cavity, of the valve element and divides the pilot valve cavity into a rodless cavity and a rod cavity. A first cold oil inlet formed in the rodless cavity and the array valve group form a pilot control half bridge which is used for controlling the position of a valve core; the array valve group comprises a plurality of high-speed switch valves communicated with the first cold oil outlet; the position change of the valve element controls the flow of the main oil way, and proportional adjustment of high-temperature fluid is achieved. The rod cavity communicates with the second cold oil inlet, the pilot oil way is a cold oil way, and the main oil way is used for controlling high-temperature fluid. By arranging the multiple high-speed switch valves connected in parallel, the response speed can be increased, fault tolerance can be achieved, and meanwhile the adjusting precision can be improved by selectively opening and closing the high-speed switch valves.

Description

Technical Field

[0001] The present invention belongs to the technical field of proportional control valves, and in particular relates to a high-temperature fluid proportional control valve piloted by a digital valve and a control method thereof. Background Art

[0002] In high-temperature fluid regulation applications (such as engine fuel and steam regulation systems), working fluid temperatures often exceed 600°C. Conventional electromechanical actuators cannot directly drive the main valve core due to temperature limitations. Therefore, "pilot-driven" technology is commonly used in this field, indirectly controlling the throttling of the high-temperature main valve via a low-temperature pilot fluid. The current mainstream solution uses a servo valve as a pilot, controlling the main valve core's movement in response to command via fluid flow, proportionally adjusting the flow through the main valve core. Because the hot fluid or steam regulated by the main valve core is very high, the pilot fluid must maintain a constant leak to ensure continuous circulation and prevent overheating. Conventional methods involve bypassing the main valve core with a fixed orifice, resulting in continuous leakage. This approach reduces response speed. Furthermore, using a servo valve as a pilot valve to regulate the main valve core has low contamination resistance, low reliability, and poor failure modes, which can easily lead to full opening of the main valve core. Furthermore, servo valves have strict operating environment requirements and rely on continuous analog signal input, making them susceptible to electromagnetic interference and difficult to implement nonlinear compensation. Summary of the Invention

[0003] In order to solve the problems in the above-mentioned background technology, the present invention provides a high-temperature fluid proportional control valve and control method with a digital valve pilot, which realizes selective control of the high-speed switching valve by adopting an array valve group, improves the adjustment accuracy, realizes on-demand adjustment and reduces overflow loss.

[0004] The first object of the present invention is to provide a high-temperature fluid proportional control valve with a digital valve pilot, the high-temperature fluid proportional control valve comprising a valve body, a valve core, an array valve group, and a control oil circuit, wherein:

[0005] A pilot valve chamber and a main valve chamber isolated from each other are formed in the valve body; the two ends of the valve core are slidably connected in the pilot valve chamber and the main valve chamber respectively, and a piston is provided at the end of the valve core extending into the pilot valve chamber, which separates the pilot valve chamber into a rodless chamber and a rod chamber; a first cold oil inlet and a first cold oil outlet are provided on the rodless chamber, and a second cold oil inlet is provided on the rod chamber; a high-temperature oil inlet and a high-temperature oil outlet are provided on the main valve chamber;

[0006] The array valve group includes a plurality of high-speed on-off valves arranged in parallel, each of which corresponds to a plurality of branch pipelines. The two ends of the high-speed on-off valves are respectively connected to a first main pipeline and a second main pipeline through the branch pipelines. The first main pipeline is connected to a first cold oil outlet, and the second main pipeline is connected to the oil tank. A damping orifice is provided on the oil inlet pipeline connected to the first cold oil inlet. The plurality of high-speed on-off valves are normally open high-speed on-off valves and / or normally closed high-speed on-off valves.

[0007] The control oil circuit includes a pilot oil circuit and a main oil circuit. The pilot oil circuit is used to control the pressure of the rodless chamber to change the position of the valve core in the valve body; the change in the position of the valve core controls the flow rate of the main oil circuit.

[0008] Furthermore, when the array valve group includes a plurality of high-speed switch valves arranged in parallel, at least one of the high-speed switch valves is a normally open high-speed switch valve, and the rest are normally closed high-speed switch valves;

[0009] The normally closed high-speed switch valve is in a closed state when it is not powered, and the normally open high-speed switch valve is in a normally open state when it is not powered.

[0010] Furthermore, a spring is fixed between the piston and the bottom wall of the rodless chamber; in the initial state, the spring is in a compressed state and applies pressure to the valve core, so that one end of the valve core blocks the high-temperature oil outlet.

[0011] Furthermore, the valve core is a heat conductor, and the valve core located in the main valve cavity is in contact with the high-temperature oil, transferring the heat of the hot oil in the main oil circuit to the cold oil in the pilot oil circuit.

[0012] Furthermore, the movement of the valve core in the main valve cavity can proportionally control the areas of the high-temperature oil inlet and the high-temperature oil outlet.

[0013] Furthermore, the oil inlet pipeline of the first cold oil inlet is further connected to an oil inlet branch pipeline, the oil inlet branch pipeline is communicated with the second cold oil inlet, and the damping hole is connected between the connection point of the oil inlet branch pipeline and the oil inlet pipeline and the first cold oil inlet;

[0014] The system pressure acts on the rod cavity from the oil inlet pipeline, and the system pressure in the rod cavity remains constant.

[0015] Furthermore, the invention also includes a controller, which controls the opening and closing of the high-speed switching valve.

[0016] Furthermore, a position sensor is provided at the end of the piston, and the controller controls the pilot oil circuit to move the piston to a certain position. The position sensor feeds back the position of the piston in the pilot valve cavity, and the position of the valve core feeds back the flow rate in the main oil circuit.

[0017] Furthermore, a first pressure sensor is provided on the front end pipeline of the damping hole, and the first pressure sensor is used to collect the pressure acting on the rod cavity; a second pressure sensor is provided on the rear end pipeline of the damping hole, and the second pressure sensor is used to collect the pressure acting on the rodless cavity; a third pressure sensor is provided on the pipeline of the high-temperature oil inlet, and the third pressure sensor is used to collect the high-temperature oil inlet pressure; a fourth pressure sensor is provided on the pipeline of the high-temperature oil outlet, and the fourth pressure sensor is used to collect the high-temperature oil outlet pressure.

[0018] A second object of the present invention is to provide a control method for a high-temperature fluid proportional control valve piloted by a digital valve, which is implemented based on any of the above-mentioned high-temperature fluid proportional control valves, comprising:

[0019] Initial state control mode: Multiple normally closed high-speed on-off valves in the array valve group are in the de-energized closed state, and the normally open high-speed on-off valves are in the de-energized normally open state. The system pressure formed by the high-pressure, low-temperature cold oil acts on the rod cavity. After the oil passes through the damping orifice, the pressure decreases and enters the rodless cavity from the first cold oil inlet. The oil in the rodless cavity flows back to the oil tank through the normally open high-speed on-off valve. The valve core moves to the equilibrium position, the valve core is stable, and the main oil circuit is not conductive;

[0020] Main oil circuit flow increase control mode: Controls the opening of one or more normally closed high-speed on-off valves and normally open high-speed on-off valves in the array valve group. The pressure in the rodless cavity of the valve core decreases, causing the valve core to be unbalanced and move toward the rodless cavity until the force on the valve core is balanced. The valve core opening increases, and the flow in the main oil circuit increases.

[0021] Main oil circuit flow reduction control mode: According to the flow reduction demand of the main oil circuit, one or more high-speed switching valves in the control array valve group are closed, the pressure in the rodless chamber of the valve core increases, the force on the valve core is unbalanced and moves toward the rod chamber until the force on the valve core is balanced, the valve core opening is reduced, and the flow of the main oil circuit is reduced.

[0022] Compared with the prior art, the present invention has the following beneficial effects:

[0023] The high-temperature fluid proportional control valve of the present invention includes a valve body, a valve core, an array valve group and a control oil circuit. The array valve group includes a plurality of high-speed switching valves arranged in parallel. The plurality of high-speed switching valves arranged in parallel correspond to a plurality of branch pipelines. The two ends of the high-speed switching valve are respectively connected to the first main pipeline and the second main pipeline through the branch pipelines. The first main pipeline is connected to the first cold oil outlet, and the second main pipeline is connected to the oil tank; a damping hole is provided on the oil inlet pipeline connected to the first cold oil inlet; the plurality of high-speed switching valves are normally open high-speed switching valves and / or normally closed high-speed switching valves; the plurality of high-speed switching valves arranged in parallel can work independently or in parallel, which can not only improve the response speed but also be fault-tolerant. When some high-speed switching valves fail, they can still work normally. Using high-speed switching valves instead of the downstream damping hole not only improves the adjustment accuracy.

[0024] In addition, this application utilizes multiple high-speed on-off valves to form a digital valve, replacing the less reliable electro-hydraulic servo valve, thereby improving system reliability and simplifying the system structure. A normally open high-speed on-off valve is also used to replace the downstream throttle orifice. During stable operation, the normally open high-speed on-off valve remains open to ensure pilot fluid circulation and prevent oil overheating. When a high-speed response is required, the normally open high-speed on-off valve closes, which can improve the response speed of closing the main oil circuit. The main purpose of using the normally open high-speed on-off valve instead of the throttle orifice is to make downstream leakage controllable. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0026] Figure 1 This is a structural diagram of the high-temperature fluid proportional control valve of the present invention;

[0027] Figure 2 This is a simplified structural diagram of the high-temperature fluid proportional control valve of the present invention;

[0028] Figure 3 This is a schematic diagram of the control oil circuit of the high-temperature fluid proportional control valve of the present invention;

[0029] Figure 4 Schematic diagram of the initial state of the high-temperature fluid proportional control valve of the present invention;

[0030] Figure 5 Schematic diagram of the main oil circuit flow rate increase process of the high-temperature fluid proportional control valve of the present invention (I);

[0031] Figure 6Schematic diagram of the main oil circuit flow rate increase process of the high-temperature fluid proportional control valve of the present invention (II);

[0032] Figure 7 Schematic diagram of the main oil circuit flow reduction process of the high-temperature fluid proportional control valve of the present invention;

[0033] Among them: 1-valve body, 11-pilot valve chamber, 111-rodless chamber, 112-rod chamber, 113-first cold oil inlet, 114-first cold oil outlet, 115-second cold oil inlet, 12-main valve chamber, 121-high-temperature oil inlet, 122-high-temperature oil outlet, 13-oil inlet pipeline, 14-damping hole, 15-oil inlet branch pipeline, 2-valve core, 21-piston, 3-array valve group, 31-normally open high-speed switching valve, 32-normally closed high-speed switching valve, 33-branch pipeline, 34-first main pipeline, 35-second main pipeline, 36-oil tank, 4-pilot oil circuit, 5-main oil circuit, 6-spring. DETAILED DESCRIPTION

[0034] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making any creative efforts are within the scope of protection of the present invention.

[0035] The following is combined with Figure 1 To the attached Figure 7 The present invention is described in detail with reference to specific embodiments.

[0036] like Figures 1 to 7 As shown, the present invention provides a high-temperature fluid proportional control valve with a digital valve pilot, the high-temperature fluid proportional control valve includes a valve body 1, a valve core 2, an array valve group 3 and a control oil circuit, wherein:

[0037] A pilot valve chamber 11 and a main valve chamber 12, which are isolated from each other, are formed in the valve body 1; the two ends of the valve core 2 are slidably connected in the pilot valve chamber 11 and the main valve chamber 12, respectively, and a piston 21 is provided at the end of the valve core 2 extending into the pilot valve chamber 11. The piston 21 divides the pilot valve chamber 11 into a rodless chamber 111 and a rod chamber 112; the rodless chamber 111 is provided with a first cold oil inlet 113 and a first cold oil outlet 114, and the rod chamber 112 is provided with a second cold oil inlet 115; the main valve chamber 12 is provided with a high-temperature oil inlet 121 and a high-temperature oil outlet 122;

[0038] The array valve group 3 includes a plurality of high-speed switching valves arranged in parallel, and the plurality of high-speed switching valves arranged in parallel correspond to a plurality of branch pipelines 33. The two ends of the high-speed switching valves are respectively connected to the first main pipeline 34 and the second main pipeline 35 through the branch pipeline 33. The first main pipeline 34 is connected to the first cold oil outlet 114, and the second main pipeline 35 is connected to the oil tank 36. A damping hole 14 is provided on the oil inlet pipeline 13 connected to the first cold oil inlet 113. The first cold oil inlet 113, the damping hole 14 and the array valve group 3 provided on the rodless cavity 111 constitute a pilot control half bridge for controlling the position of the valve core 2. The plurality of high-speed switching valves are normally open high-speed switching valves 31 and / or normally closed high-speed switching valves. 32; Through the coordinated work of multiple high-speed switching valves, continuous proportional adjustment of the cold oil can be achieved, and when a single valve fails, the remaining valves can still maintain basic functions, and the fault tolerance is strong; at the same time, due to the short response time of the high-speed switching valve, it can meet the special needs of fast response under high-temperature conditions; It should be noted that the high-speed switching valve is a valve that can be opened or closed quickly in a very short time. Its core characteristics are fast response speed and high operating frequency. It can complete the opening and closing action in a very short time, and in this application, the high-speed switching valve is a discrete switch. This application does not introduce the specific structure of the high-speed switching valve. Those skilled in the art can choose the high-speed switching valves commonly used on the market, or design it according to their needs.

[0039] See Figure 3 The high-temperature fluid proportional control valve of the present application is divided into two parts, one part is the pilot drive part, and the other part is the main oil circuit part. Therefore, the control oil circuit includes the pilot oil circuit 4 and the main oil circuit 5. The pilot oil circuit 4 uses cold oil circulation to work, and the main oil circuit 5 is a high-temperature fluid. The pilot oil circuit 4 is used to control the pressure of the rodless chamber 111 to change the position of the valve core 2 in the valve body 1; the position change of the valve core 2 can directly change the oil outlet opening of the main oil circuit 5, thereby controlling the flow rate of the high-temperature fluid. The present application avoids the mixing of high-temperature fluid and low-temperature oil by isolating the pilot oil circuit 4 and the main oil circuit 5 from each other. The use of cold oil circulation in the pilot drive part can reduce the thermal stress of the control components, avoid problems such as aging of precision components caused by high temperature, and extend the service life of precision components.

[0040] In some embodiments, see Figures 2 to 6, when the array valve group 3 includes a plurality of high-speed switch valves arranged in parallel, at least one of the high-speed switch valves is a normally open high-speed switch valve 31, and the rest are normally closed high-speed switch valves 32; the normally closed high-speed switch valve 32 is in a closed state when not powered, and the normally open high-speed switch valve 31 is in a normally open state when not powered. The present application utilizes a plurality of high-speed switch valves to form a digital valve, replacing the low-reliability electro-hydraulic servo valve, thereby improving the reliability of the system and simplifying the system structure. At the same time, the normally open high-speed switch valve 31 is used as the basic flow channel to replace the downstream damping hole. When working stably, the normally open high-speed switch valve 31 is continuously opened to ensure the circulation of the pilot fluid and avoid overheating of the oil. When a high-speed response is required, the normally open high-speed switch valve 31 is closed, which can improve the response speed of closing the main oil circuit. The main purpose of using the normally open high-speed switch valve 31 to replace the downstream damping hole is to make the downstream leakage controllable. In this application, a normally open high-speed on-off valve 31 replaces the traditional downstream damping orifice, eliminating the non-adjustability of a fixed damping orifice. Dynamic regulation of leakage is achieved by actively controlling the opening and closing of the normally open high-speed on-off valve 31. The normally closed high-speed on-off valve 32, however, is closed without power and requires power to open, serving as an auxiliary flow channel for supplementing or rapidly adjusting flow to accommodate dynamic operating conditions. It should be noted that high-speed on-off valves have lower oil cleanliness requirements than electro-hydraulic servo valves, significantly reducing the risk of sticking due to contamination.

[0041] The valve array 3 of the present invention achieves on-demand regulation through digital signals, reducing overflow losses. For example, it can reduce no-load energy consumption in engineering machinery, meeting the goal of green manufacturing. Furthermore, the high-speed switching control valve has high pollution resistance and reliability.

[0042] For example, hot oil is used as fuel. When the aircraft accelerates, the demand for fuel increases, and the opening of the main oil circuit 5 needs to be increased. Conversely, when the aircraft decelerates, the demand for fuel decreases, and the opening of the main oil circuit 5 needs to be reduced. The opening size of the main oil circuit 5 is precisely controlled by the position sensor at the piston 21. The opening of the main oil circuit 5 is determined by the position of the piston 21, and the flow rate of the main oil circuit 5 is also determined. The position of the piston 21 is adjusted by adjusting some high-speed switching valves. The entire adjustment process is a dynamic adjustment process with an extremely fast response speed.

[0043] In some embodiments, a spring 6 is further secured between the piston 21 and the bottom wall of the rodless chamber 111. Initially, the spring 6 is compressed and applies pressure to the valve core 2, causing one end of the valve core 2 to block the high-temperature oil outlet 122. By providing spring 6, the spring force directly drives the valve core 2 to seal the high-temperature oil outlet 122 when power is lost, providing dual protection against pressure relief from the normally open, high-speed on / off valve of the array valve assembly 3. Even if the control oil circuit completely loses pressure, the valve remains closed, preventing leakage of the high-temperature medium.

[0044] In some embodiments, the valve core 2 is a heat conductor, and the valve core 2 located in the main valve cavity 12 is in contact with the high-temperature oil, transferring the heat of the hot oil in the main oil circuit 5 to the cold oil in the pilot oil circuit 4. The valve core 2 axially penetrates the pilot valve cavity 11 and the main valve cavity 12, and the main valve end (in contact with the high-temperature oil) and the pilot end (in contact with the cold oil) of the valve core 2 form a stable heat flow, avoiding local overheating and reducing the axial temperature difference of the valve core 2. Preferably, the valve core 2 is made of steel or alloy steel. It should be noted that for safety reasons, if the high-temperature fluid of 600°C is not cooled when ignited, it will cause heat accumulation, trigger material failure, and cause damage to the proportional control valve structure.

[0045] The valve core 2 of the present application moves in the main valve chamber 12 to proportionally control the area of the high temperature oil inlet 121 and the high temperature oil outlet 122, that is, to control the flow rate of the main oil circuit. Figure 1 and Figure 2 The oil inlet direction of the high-temperature oil inlet 121 is perpendicular to the sliding direction of the valve core 2, and the high-temperature oil outlet 122 is arranged opposite to the valve core 2, and the cross-sectional size of the valve core 2 can cover the high-temperature oil outlet 122. The oil inlet direction of the high-temperature oil inlet 121 of the present application is perpendicular to the sliding direction of the valve core 2, so that the radial force of the valve core 2 is consistent, and the heating area of the valve core 2 is large, so that heat can be quickly transferred to the other end of the valve core 2. At the same time, the high-temperature oil outlet 122 is arranged opposite to the valve core 2 to form a symmetrical flow field, so that the force on the valve core 2 is more balanced.

[0046] In some embodiments, see Figure 2The oil inlet pipe 13 of the first cold oil inlet port 113 is also connected to an oil branch pipe 15, and the oil branch pipe 15 is communicated with the second cold oil inlet port 115, and the damping hole 14 is connected between the connection point of the oil branch pipe 15 and the oil inlet pipe 13 and the first cold oil inlet port 113; the system pressure acts on the rod chamber 112 from the oil branch pipe 15, and the system pressure in the rod chamber 112 is kept constant by adjusting the system pressure in advance; of course, a pressure regulating valve can also be provided on the oil branch pipe 15, and the system pressure in the rod chamber 112 can be adjusted to remain constant by the pressure regulating valve. The cold oil acts on the rodless chamber 111 through the damping hole 14. After passing through the damping hole 14, the cold oil generates a pressure drop, making the pressure of the rodless chamber 111 lower than the initial pressure of the system. The oil inlet branch line 15 branches from the oil inlet line 13 and is connected to the rod chamber 112, directly introducing the system pressure into the rod chamber, ensuring that the pressure in the rod chamber 112 remains constant, and preventing the rod chamber 112 from being affected by the main oil circuit, resulting in valve core oscillation and affecting the response speed. It should be noted that the second cold oil inlet 115 of the present application is both an oil inlet and an oil outlet. When the piston 21 moves toward the rod chamber 112, the oil in the rod chamber 112 flows back from the second cold oil inlet 115, and the rod chamber 112 is connected to the system oil. The second cold oil inlet 115 is used to realize the inflow and outflow of oil, and ensures that the oil pressure in the rod chamber 112 is always the system oil pressure P0.

[0047] Specifically, the present application also includes a controller that controls the opening and closing of the high-speed switching valve. It should be noted that the controller in the embodiment of the present invention has the function of acquiring information and controlling the status of certain devices according to a set program.

[0048] Furthermore, a position sensor is provided at the end of piston 21. The controller controls pilot oil circuit 4 to move piston 21 to a certain position. The position sensor provides feedback on the position of piston 21 within pilot valve chamber 11, and the position of valve core 2 provides feedback on the flow rate in main oil circuit 5. During use, the controller controls the opening and closing of the high-speed on-off valve to control the position of valve core 2.

[0049] In some embodiments, a first pressure sensor is provided on the front end pipeline of the damping hole 14, and the first pressure sensor is used to collect the pressure P0 acting on the rod cavity 112; a second pressure sensor is provided on the rear end pipeline of the damping hole 14, and the second pressure sensor is used to collect the pressure Pk acting on the rodless cavity 111; a third pressure sensor is provided on the pipeline of the high-temperature oil inlet 121, and the third pressure sensor is used to collect the high-temperature oil inlet pressure Pg; a fourth pressure sensor is provided on the pipeline of the high-temperature oil outlet 122, and the fourth pressure sensor is used to collect the high-temperature oil outlet pressure Pg0. The system pressure and flow are monitored in real time through sensors and data analysis, and the operating strategy is dynamically adjusted to reduce energy waste. The pressure sensor in this application is used for measuring pressure and uploading signals, and the specific product type of the sensor is not limited. It should also be noted that in this application, Pk=D 4 / (D 4 +d 4 )*P0 (Pk is the pressure in the rodless chamber 111, D is the aperture of the damping hole 14, and d is the opening aperture of the opened high-speed switching valve), Pk*Ak+Fk=P0*A0+Pg0*A1, Ak is the circular area of the end face of the piston 21, Fk is the preload force of the spring 6, A0 is the annular area of the valve core 2 acted upon by the pressure P0 in the rod chamber 112, and A1 is the area of action of the main oil circuit on the valve core. When the pressure in the rodless chamber 111 of the valve core increases, the force on the valve core 2 becomes unbalanced, and the valve core 2 moves to the right, reducing the spring force until the force on the valve core 2 is balanced, causing the valve core 2 to open smaller, thereby regulating the flow rate in the main oil circuit 5 to decrease; when the pressure in the rodless chamber 111 of the valve core decreases, the force on the valve core 2 becomes unbalanced, and the valve core 2 moves to the left, increasing the spring force until the force on the valve core 2 is balanced, causing the valve core 2 to open wider, thereby regulating the flow rate in the main oil circuit 5 to increase;

[0050] The present invention also provides a control method for a high-temperature fluid proportional control valve piloted by a digital valve, which is implemented based on any one of the above-mentioned high-temperature fluid proportional control valves, comprising:

[0051] Initial state control mode (see Figure 4 ): Multiple normally closed high-speed switch valves 32 in the array valve group 3 are in a closed state without power supply, and the normally open high-speed switch valve 31 is in a normally open state without power supply. The system pressure formed by the high-pressure and low-temperature cold oil acts on the rod chamber. After the oil passes through the damping hole 14, the pressure decreases and enters the rodless chamber 111 from the first cold oil inlet 113. The oil in the rodless chamber 111 flows back to the oil tank 36 through the normally open high-speed switch valve 31 (as the red arrow represents the flow direction of the oil circuit), the valve core 2 moves to the equilibrium position, the valve core 2 is stable, and the main oil circuit 5 is not conductive; when a spring 6 is fixed between the piston 21 and the bottom wall of the rodless chamber 111, in the initial state, the pressure in the rodless chamber 111 and the spring force of the spring 6 are balanced with the pressure in the rod chamber 112, the valve core 2 is stable, and the main oil circuit 5 is not conductive.

[0052] Main oil flow increase control mode (see Figure 5 and Figure 6 ): Control the single or multiple normally closed high-speed switch valves 32 and the normally open high-speed switch valve 31 in the array valve group 3 to open, the pressure of the rodless chamber 111 of the valve core is reduced, and the valve core 2 is unbalanced and moves in the direction of the rodless chamber 111 (i.e., to the left, as shown in the figure). Figure 4 As shown by the yellow arrow on the valve core 2 in the figure, the valve core 2 moves until the force on the valve core 2 is balanced, the valve core 2 opens wider, and the flow rate of the main oil circuit 5 increases (as shown in the figure). Figure 4 and Figure 5 The red arrows in the figure represent the flow direction of the oil circuit); specifically, according to the flow increase demand of the main oil circuit 5, the controller controls the single or multiple normally closed high-speed switch valves 32 and the normally open high-speed switch valves 31 in the array valve group 3 to open. The opening of the single or multiple normally closed high-speed switch valves 32 and the normally open high-speed switch valves 31 is equivalent to the increase of the damping hole downstream of the rodless chamber 111 to varying degrees (each opened high-speed switch valve is equivalent to a downstream damping hole). According to Pk=D 4 / (D 4 +d 4 )*P0 (Pk is the pressure in the rodless chamber 111, D is the aperture of the damping hole 14, and d is the opening aperture of the opened high-speed switching valve), Pk*Ak+Fk=P0*A0+Pg0*A1, Fk is the preload force of the spring 6, the pressure in the rodless chamber 111 of the valve core decreases, the force on the valve core 2 is unbalanced, and it moves to the left to increase the spring force until the force on the valve core 2 is balanced, and the opening of the valve core 2 increases, thereby regulating the flow in the main oil circuit 5 to increase.

[0053] Main oil flow reduction control mode (see Figure 7 ): According to the flow reduction demand of the main oil circuit, the single or multiple high-speed switch valves in the control array valve group are closed, so that the pressure of the rodless chamber 111 of the valve core 2 increases, and the valve core 2 is subjected to unbalanced force and moves toward the rod chamber 112 (i.e., to the right, as shown in the figure). Figure 7 As shown by the yellow arrow on the valve core 2 in the figure) until the force on the valve core 2 is balanced, the valve core 2 opening decreases, and the flow rate of the main oil circuit 5 decreases (as shown in the figure). Figure 7 The red arrow in the figure represents the flow direction of the oil circuit). In this application, the controller controls the closing of one or more high-speed switching valves in the array valve group 3, which is equivalent to reducing the damping hole downstream of the rodless chamber 111 to varying degrees (each open high-speed switching valve is equivalent to a downstream damping hole). According to Pk=D 4 / (D 4 +d 4)*P0 (Pk is the pressure in the rodless chamber 111, D is the aperture of the damping hole 14, and d is the opening aperture of the opened high-speed switching valve), Pk*Ak+Fk=P0*A0+Pg0*A1, Fk is the preload force of the spring 6, the pressure in the rodless chamber 111 of the valve core increases, the force on the valve core 2 is unbalanced, and it moves to the right to reduce the spring force until the force on the valve core 2 is balanced, and the opening of the valve core 2 becomes smaller, thereby adjusting the flow of the main oil circuit 5 to decrease. It is worth emphasizing that according to the flow reduction requirement of the main oil circuit 5, it is necessary to increase the pressure in the rodless chamber 111 to a certain fixed value. The process of increasing the pressure in the rodless chamber 111 is achieved by closing the high-speed switching valve. During the adjustment process, it can be adjusted by closing one high-speed switching valve and two high-speed switching valves in turn. When the pressure in the rodless chamber 111 is about to reach the fixed pressure value, that is, when it is about to reach the limit state, at least one high-speed switching valve is in the open state ( Figure 7 (In the figure, two high-speed switching valves are in the open state). The pressure can be adjusted to fluctuate around a fixed pressure value by adjusting the open high-speed switching valve.

[0054] The present invention is further described above with the aid of specific embodiments. However, it should be understood that the specific description herein should not be construed as limiting the essence and scope of the present invention. Various modifications made to the above embodiments by ordinary technicians in this field after reading this specification are all within the scope of protection of the present invention.

Claims

1. A high-temperature fluid proportional control valve with a digital valve pilot, characterized in that: The high-temperature fluid proportional control valve includes a valve body, a valve core, an array valve group and a control oil circuit, wherein: A pilot valve chamber and a main valve chamber isolated from each other are formed in the valve body; both ends of the valve core are slidably connected in the pilot valve chamber and the main valve chamber respectively, and a piston is provided at one end of the valve core extending into the pilot valve chamber, and the piston divides the pilot valve chamber into a rodless chamber and a rod chamber; a first cold oil inlet and a first cold oil outlet are provided on the rodless chamber, and a second cold oil inlet is provided on the rod chamber; a high-temperature oil inlet and a high-temperature oil outlet are provided on the main valve chamber; The array valve group includes a plurality of high-speed on-off valves arranged in parallel, each of which corresponds to a plurality of branch pipelines. Both ends of the high-speed on-off valves are connected to a first main pipeline and a second main pipeline respectively through branch pipelines. The first main pipeline is connected to the first cold oil outlet, and the second main pipeline is connected to the oil tank. A damping orifice is provided on the oil inlet pipeline connected to the first cold oil inlet. The plurality of high-speed on-off valves are normally open high-speed on-off valves and / or normally closed high-speed on-off valves. The control oil circuit includes a pilot oil circuit and a main oil circuit. The pilot oil circuit is used to control the pressure of the rodless chamber to change the position of the valve core in the valve body; the position change of the valve core controls the flow rate of the main oil circuit.

2. The high-temperature fluid proportional control valve with digital valve pilot according to claim 1, characterized in that: When the array valve group includes a plurality of high-speed switch valves arranged in parallel, at least one of the high-speed switch valves is a normally open high-speed switch valve, and the rest are normally closed high-speed switch valves; The normally closed high-speed switch valve is in a closed state without power supply, and the normally open high-speed switch valve is in a normally open state without power supply.

3. The high-temperature fluid proportional control valve with digital valve pilot according to claim 2, characterized in that: A spring is also fixed between the piston and the bottom wall of the rodless chamber; in an initial state, the spring is in a compressed state and applies pressure to the valve core, so that one end of the valve core blocks the high-temperature oil outlet.

4. The high-temperature fluid proportional control valve with digital valve pilot according to claim 1, characterized in that: The valve core is a heat conductor, and the valve core located in the main valve cavity is in contact with high-temperature oil, transferring the heat of the hot oil in the main oil circuit to the cold oil in the pilot oil circuit.

5. The high-temperature fluid proportional control valve with digital valve pilot according to claim 4, characterized in that: The valve core moves in the main valve chamber to proportionally control the areas of the high-temperature oil inlet and the high-temperature oil outlet.

6. The high-temperature fluid proportional control valve with digital valve pilot according to claim 1, characterized in that: The oil inlet pipeline of the first cold oil inlet is further connected to an oil inlet branch pipeline, the oil inlet branch pipeline is communicated with the second cold oil inlet, and the damping hole is connected between the connecting point of the oil inlet branch pipeline and the oil inlet pipeline and the first cold oil inlet; The system pressure acts on the rod chamber from the oil inlet branch pipeline, and the system pressure in the rod chamber is constant.

7. The high-temperature fluid proportional control valve with digital valve pilot according to claim 1, characterized in that: A controller is also included, which controls the opening and closing of the high-speed switching valve.

8. The high-temperature fluid proportional control valve with digital valve pilot according to claim 7, characterized in that: A position sensor is provided at the end of the piston. The controller controls the pilot oil circuit to move the piston to a certain position. The position sensor feeds back the position of the piston in the pilot valve cavity, and the position of the valve core feeds back the flow rate in the main oil circuit.

9. The high-temperature fluid proportional control valve with digital valve pilot according to claim 7, characterized in that: A first pressure sensor is provided on the front end pipeline of the damping hole, and the first pressure sensor is used to collect the pressure acting on the rod cavity; a second pressure sensor is provided on the rear end pipeline of the damping hole, and the second pressure sensor is used to collect the pressure acting on the rodless cavity; a third pressure sensor is provided on the pipeline of the high-temperature oil inlet, and the third pressure sensor is used to collect the high-temperature oil inlet pressure; a fourth pressure sensor is provided on the pipeline of the high-temperature oil outlet, and the fourth pressure sensor is used to collect the high-temperature oil outlet pressure.

10. A control method for a high-temperature fluid proportional control valve piloted by a digital valve, implemented based on the high-temperature fluid proportional control valve according to any one of claims 1 to 9, characterized in that: include: Initial state control mode: Multiple normally closed high-speed on-off valves in the array valve group are in the de-energized closed state, and the normally open high-speed on-off valves are in the de-energized normally open state. The system pressure formed by the high-pressure, low-temperature cold oil acts on the rod cavity. After the oil passes through the damping orifice, the pressure decreases and enters the rodless cavity from the first cold oil inlet. The oil in the rodless cavity flows back to the oil tank through the normally open high-speed on-off valve. The valve core moves to the equilibrium position, the valve core is stable, and the main oil circuit is not conductive; Main oil circuit flow increase control mode: Controls the opening of one or more normally closed high-speed on-off valves and normally open high-speed on-off valves in the array valve group. The pressure in the rodless cavity of the valve core decreases, causing the valve core to be unbalanced and move toward the rodless cavity until the force on the valve core is balanced. The valve core opening increases, and the flow in the main oil circuit increases. Main oil circuit flow reduction control mode: According to the flow reduction demand of the main oil circuit, one or more high-speed switching valves in the control array valve group are closed, so that the pressure in the rodless chamber of the valve core increases, the force on the valve core is unbalanced and moves toward the rod chamber until the force on the valve core is balanced, the valve core opening is reduced, and the flow of the main oil circuit is adjusted to decrease.

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