Opposed direct-drive digital plunger pump and flow control method

Abstract

The invention provides an opposed direct-drive digital plunger pump and a flow control method. The opposed direct-drive digital plunger pump comprises a control device and at least one liquid output unit, the control device is used for regulating and controlling the total output flow of the liquid output unit so as to be suitable for at least one output state of full-flow output, partial-flow output, extremely-small-flow output and zero-flow output. According to the embodiment of the invention, the driving frequencies and the driving directions of the two oppositely-distributed driving devices are controlled in a coordinated manner through the digital control device, and all or part of fluid alternately flows between the two plunger cavities in combination with the connecting flow channel structure between the two plunger cavities; therefore, the total output flow can be rapidly adjusted in real time according to the liquid use requirement, and rapid switching among multiple flow output states can be achieved so as to meet the complex liquid use scenes such as intermittent liquid use, full-flow liquid use, partial-flow liquid use and extremely-small-flow liquid use.

Description

Technical Field

[0001] The present disclosure relates to the technical field of plunger pumps, and in particular to an opposed direct-drive digital plunger pump and a flow control method. Background Art

[0002] The plunger pump is the core power equipment of the fluid supply system of the fully-mechanized coal mining face, providing high-pressure emulsion with a certain pressure for the hydraulic support. In order to improve the performance and efficiency of the fully-mechanized coal mining face fluid supply system and reduce energy consumption, the plunger pump needs to quickly adjust the output flow rate according to the actual fluid demand of the hydraulic support. According to the different power mechanisms, the plunger pump can be divided into crank slider type, swash plate type, cam type, direct drive type, etc.

[0003] For crank slider, swash plate, and cam plunger pumps, the current coal mine fully mechanized working face fluid supply system mostly adopts valve-controlled flow control strategies, such as electromagnetic unloading valves, etc. However, on the one hand, the valve-controlled system has high energy consumption and the lost energy is dissipated in the form of heat energy; on the other hand, although the output flow can be changed by using a variable frequency motor to adjust the output speed of the crank slider or by changing the angle of the swash plate mechanism to adjust the displacement, the response speed of the output flow is slow due to the inertia of the movement of mechanical parts, and it is difficult to meet the needs of fluid supply scenarios such as long-distance fluid supply or central fluid supply in coal mines.

[0004] The digital plunger pump uses digital signals to control the output flow rate, and uses high-speed switch valves to quickly open and close, or adjusts the output flow rate by adjusting the driving frequency of high-frequency linear motors, electro-hydraulic actuators and other high-frequency drive devices to achieve rapid flow response. Compared with the digital plunger pump with a high-speed switch valve structure, the direct-drive digital plunger pump that uses a high-frequency drive device as a power source has fewer intermediate transmission links, and has the advantages of simple structure and control, and easy maintenance. However, linear motors or electro-hydraulic actuators usually have a minimum non-zero execution speed or non-zero stroke, so the corresponding digital plunger pump has a limited output flow range, and cannot achieve continuous adjustment from zero to maximum flow, making it difficult to achieve extremely small flow output and zero flow output requirements, especially unable to meet the frequent intermittent fluid supply scenarios of coal mine comprehensive mining working faces. Summary of the invention

[0005] In view of this, the present disclosure aims to provide an opposed direct-drive digital plunger pump and a flow control method to solve the technical problems in the prior art that the output flow range of the plunger pump is limited, continuous adjustment from zero to maximum flow cannot be achieved, and it is difficult to achieve the requirements of extremely small flow output and zero flow output.

[0006] One aspect of the present disclosure provides an opposed direct-drive digital piston pump, comprising a control device and at least one liquid output unit, wherein the control device is used to regulate the total output flow of the liquid output unit to adapt to at least one output state of full flow output, partial flow output, very low flow output and zero flow output.

[0007] In some embodiments, there are multiple liquid output units, and the multiple liquid output units are arranged in sequence according to a predetermined order.

[0008] In some embodiments, the liquid output unit includes a control unit and a first plunger chamber and a second plunger chamber that are interconnected and oppositely arranged. The control unit is connected to the control device. The first plunger chamber and the second plunger chamber are connected through a plunger chamber connecting channel. A movable first plunger and a movable second plunger are respectively arranged in the first plunger chamber and the second plunger chamber. The first plunger is connected to a first driving device through a first plunger rod, and the second plunger is connected to a second driving device through a second plunger rod.

[0009] In some embodiments, the first driving device and / or the second driving device is an electro-hydraulic actuator or a motor.

[0010] In some embodiments, the plunger cavity connecting flow channel is connected to the low-pressure circuit through a first flow channel, and the plunger cavity connecting flow channel is also connected to the high-pressure circuit through a second flow channel.

[0011] In some embodiments, a liquid suction one-way valve is disposed on the first flow channel, and a liquid discharge one-way valve is disposed on the second flow channel.

[0012] One aspect of the present disclosure provides a flow control method for an opposed direct-drive digital plunger pump, comprising:

[0013] Controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach the zero position respectively based on the maximum driving frequency;

[0014] When the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction. After the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the maximum drive frequency to achieve liquid discharge.

[0015] In some embodiments, it also includes:

[0016] When the first plunger and the second plunger reach the zero position, in response to the partial flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on a first predetermined driving frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the first predetermined driving frequency to achieve liquid discharge.

[0017] In some embodiments, it also includes:

[0018] When the first plunger and the second plunger reach the zero position, in response to the minimum flow output signal, the first drive device is controlled to drive the first plunger based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency; when the first plunger reaches the end of the stroke, the first drive device is controlled to drive the first plunger to move in the second direction based on the second predetermined drive frequency, and the second drive device is controlled to drive the second plunger to move in the second direction based on the minimum drive frequency to achieve liquid discharge; when the first plunger and the second plunger reach the end of the stroke at the same time, the first drive device is controlled to drive the first plunger to move in the first direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency.

[0019] In some embodiments, it also includes:

[0020] When the first plunger and the second plunger reach the zero position, in response to the zero flow output signal, the first driving device and the second driving device are controlled to drive the first plunger and the second plunger to move in the first direction based on a third predetermined driving frequency.

[0021] The disclosed embodiment coordinates and controls the driving frequency and driving direction of two oppositely distributed driving devices through a digital control device, and then combines the connecting flow channel structure between the two plunger chambers to enable all or part of the fluid to flow alternately between the two plunger chambers, thereby being able to quickly adjust the total output flow in real time according to liquid demand, thereby being able to quickly switch between multiple flow output states to meet complex liquid usage scenarios such as intermittent liquid usage, full flow liquid usage, partial flow liquid usage, and extremely small flow liquid usage.

[0022] In order to make the above-mentioned objectives, features and advantages of the present disclosure more obvious and easy to understand, preferred embodiments are specifically cited below and described in detail with reference to the attached drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In the drawings that are not necessarily drawn to scale, the same reference numerals may describe similar parts in different views. The same reference numerals with letter suffixes or different letter suffixes may represent different instances of similar parts. The drawings generally illustrate various embodiments by way of example and not limitation, and together with the specification and claims, are used to illustrate the disclosed embodiments. When appropriate, the same reference numerals are used throughout the drawings to refer to the same or similar parts. Such embodiments are illustrative and are not intended to be exhaustive or exclusive embodiments of the present apparatus or method. The drawings described herein are used to provide a further understanding of the present disclosure and constitute a part of this application. The illustrative embodiments of the present disclosure and their descriptions are used to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the drawings:

[0024] Figure 1 is a schematic diagram of the arrangement of an opposed direct-drive digital plunger pump provided in an embodiment of the present disclosure;

[0025] Figure 2 It is a schematic diagram of the zero position in the opposed direct-drive digital plunger pump provided in the embodiment of the present disclosure;

[0026] Figure 3 is a schematic diagram of an opposed direct-drive digital plunger pump provided in an embodiment of the present disclosure for full flow output;

[0027] Figure 4 It is a schematic diagram of an opposed direct-drive digital plunger pump provided in an embodiment of the present disclosure for partial flow output;

[0028] Figure 5 It is a schematic diagram of an opposed direct-drive digital plunger pump provided in an embodiment of the present disclosure for outputting extremely small flow rates;

[0029] Figure 6 It is a schematic diagram of an opposed direct-drive digital plunger pump provided in an embodiment of the present disclosure for zero full flow output.

[0030] The above drawings include the following reference numerals:

[0031] 1-first liquid output unit; 2-low-pressure circuit; 3-high-pressure circuit; 4-second liquid output unit; 5-third liquid output unit; 6-control device; 11-first drive device; 12-second drive device; 21-first plunger rod; 22-second plunger rod; 31-first plunger; 32-second plunger; 41-first plunger cavity; 42-second plunger cavity; 51-plunger cavity connecting flow channel; 61-liquid suction one-way valve; 71-liquid discharge one-way valve; 81-control unit. DETAILED DESCRIPTION

[0032] The specific embodiments of the present disclosure are described in detail below with reference to the accompanying drawings, but are not intended to limit the present disclosure.

[0033] It should be understood that various modifications may be made to the embodiments disclosed herein. Therefore, the above description should not be considered as limiting, but merely as an example of an embodiment. Other modifications within the scope and spirit of the present disclosure will occur to those skilled in the art.

[0034] The accompanying drawings, which are incorporated in and constitute a part of the specification, illustrate embodiments of the present disclosure and, together with the general description of the present disclosure given above and the detailed description of the embodiments given below, serve to explain the principles of the present disclosure.

[0035] These and other characteristics of the present disclosure will become apparent from the following description of a preferred form of embodiment given as a non-limiting example, with reference to the attached drawings.

[0036] It should also be understood that, although the present disclosure has been described with reference to some specific examples, those skilled in the art will be able to realize many other equivalent forms of the present disclosure that have the features described in the claims and are therefore within the scope of protection defined thereby.

[0037] The above and other aspects, features and advantages of the present disclosure will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings.

[0038] Specific embodiments of the present disclosure are described hereinafter with reference to the accompanying drawings; however, it should be understood that the disclosed embodiments are merely examples of the present disclosure, which may be implemented in a variety of ways. Well-known and / or repeated functions and structures are not described in detail to avoid obscuring the present disclosure with unnecessary or redundant details. Therefore, the specific structural and functional details disclosed herein are not intended to be limiting, but merely serve as a basis and representative basis for the claims to teach those skilled in the art to use the present disclosure in a variety of ways with substantially any suitable detailed structure.

[0039] It should be noted that the terms "first", "second", etc. in the specification and claims of the present disclosure and the above-mentioned drawings are used to distinguish similar objects, and are not necessarily used to describe a specific order or sequence. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the present disclosure described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions, for example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units that are clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products, or devices.

[0040] This specification may use the phrases "in one embodiment," "in another embodiment," "in a further embodiment," or "in other embodiments," all of which may refer to one or more of the same or different embodiments according to the present disclosure.

[0041] The first embodiment of the present disclosure provides an opposed direct-drive digital plunger pump, such as Figure 1 As shown, it is suitable for working scenarios that require hydraulic supply, and is particularly suitable for liquid use scenarios that require frequent liquid supply on the fully mechanized working face of a coal mine. The opposed direct-drive digital plunger pump includes at least one liquid output unit, and the liquid output unit is used to output liquid with a predetermined flow rate. Of course, in order to increase the output flow rate, the opposed direct-drive digital plunger pump may include a plurality of the liquid output units, wherein when there are a plurality of liquid output units, the plurality of liquid output units are arranged in sequence according to a predetermined order, and the plurality of liquid units may be arranged in parallel, for example.

[0042] In this embodiment, the opposed direct-drive digital piston pump includes a control device 6 and, for example, a first liquid output unit 1, a second liquid output unit 4 and a third liquid output unit 5 arranged in parallel. The control device 6 is used to regulate the total output flow of the opposed direct-drive digital piston pump.

[0043] Here, the structure of each liquid output unit is the same. The following is a specific introduction taking the first liquid output unit 1 as an example. Specifically, the first liquid output unit 1 includes a control unit 81 and a first plunger cavity 41 and a second plunger cavity 42 that are interconnected and relatively arranged. The control unit 81 in the first liquid output unit 1 here is connected to the control device 6. It should be noted that the control unit 81 of each liquid output unit is connected to the control device 6, so that the control device 6 can regulate the output flow of each liquid output unit through the control unit 81.

[0044] Further, the first plunger cavity 41 and the second plunger cavity 42 are respectively provided with a first plunger 31 and a second plunger 32, and the first plunger 31 and the second plunger 32 respectively move in the first plunger cavity 41 and the second plunger cavity 42. Here, the first plunger cavity 41 and the second plunger cavity 42 have a predetermined stroke.

[0045] Further, the first plunger 31 is connected to the first drive device 11 through the first plunger rod 21, and the second plunger 32 is connected to the second drive device 12 through the second plunger rod 22. Under the drive of the first drive device 11 and the second drive device 12, the first plunger 31 and the second plunger 32 can move in opposite directions or in the same direction. The first drive device 11 and the second drive device 12 are high-frequency drive devices, which are electro-hydraulic actuators or motors.

[0046] Furthermore, the first plunger cavity 41 and the second plunger cavity 42 are connected via a plunger cavity connecting flow channel 51. In addition, the plunger cavity connecting flow channel 51 is connected to the low-pressure circuit 2 via the first flow channel, and the plunger cavity connecting flow channel 51 is also connected to the high-pressure circuit 3 via the second flow channel. Here, the low-pressure circuit 2 is connected to a liquid source device for absorbing liquid from the liquid source device, and the high-pressure circuit 3 is connected to a working object for discharging liquid to the working object. In order to control the flow rate of liquid absorption and discharge, a liquid absorption check valve 61 is provided on the first flow channel, and a liquid discharge check valve 71 is provided on the second flow channel.

[0047] Taking the first liquid output unit 1 as an example, the control unit 81 controls the first driving device 11 to directly drive the first plunger 31 to reciprocate in the first plunger cavity 41 at a certain driving frequency through the first plunger rod 21; and controls the second driving device 12 to directly drive the second plunger 32 to reciprocate in the second plunger cavity 42 at a certain driving frequency through the second plunger rod 22. The reciprocating motion of the first plunger 31 and the second plunger 32 here will cause the total volume of the space formed by the first plunger cavity 41, the second plunger cavity 42 and the plunger cavity connecting flow channel 51 to change in real time.

[0048] On the one hand, when the total volume of the space formed by the first plunger chamber 41, the second plunger chamber 42 and the plunger chamber connecting flow channel 51 increases, the liquid suction one-way valve 61 is controlled to open, and the liquid enters the space formed by the first plunger chamber 41, the second plunger chamber 42 and the plunger chamber connecting flow channel 51 through the low-pressure circuit 2. At this time, the first plunger chamber 41 and the second plunger chamber 42 are in a liquid suction state.

[0049] On the other hand, when the total volume of the space formed by the first plunger chamber 41, the second plunger chamber 42 and the plunger chamber connecting channel 51 decreases, the discharge check valve 71 is controlled to open, and liquid enters the high-pressure circuit 3 from the space. At this time, the first plunger chamber 41 and the second plunger chamber 42 are in a discharge state.

[0050] In addition, when the total volume of the space formed by the first plunger chamber 41, the second plunger chamber 42 and the plunger chamber connecting flow channel 51 remains unchanged, the liquid alternately flows between the first plunger chamber 41 and the second plunger chamber 42 through the plunger chamber connecting flow channel 51, and the liquid suction check valve 61 and the liquid discharge check valve 71 are controlled to be closed, and the first plunger chamber 41 and the second plunger chamber 42 are in a stopped state. In this embodiment, the control unit 81 in each of the liquid output units is used to control the output frequency of the driving device, and the opening and closing of the liquid suction check valve 61 and the liquid discharge check valve 71.

[0051] In this way, the control unit 81 of each liquid output unit is controlled by the control device 6, and the driving frequency of the driving device in each liquid output unit and the opening and closing state of the one-way valve are coordinated and controlled, so as to adjust the total output flow of the opposed direct-drive digital plunger pump.

[0052] The disclosed embodiment utilizes a digital control device to control a high-frequency driving device to directly drive the plunger to reciprocate within a predetermined stroke based on a set driving frequency, thereby realizing the suction and discharge functions.

[0053] Based on the opposed direct-drive digital plunger pump described in the first embodiment, the second embodiment of the present disclosure provides a flow control method for an opposed digital plunger pump. The flow control method can control the flow of different liquid output units, so that the opposed direct-drive digital plunger pump can switch between multiple working states. For example, rapid switching between multiple working states such as full flow output, partial flow output, extremely small flow output and no flow output can be achieved to meet complex liquid usage scenarios such as intermittent liquid usage, full flow or partial flow liquid usage, and extremely small flow liquid usage.

[0054] The flow control method of the opposed direct-drive digital plunger pump specifically controls the output flow of each of the liquid output units. In this embodiment, taking the control of the output flow of the first liquid output unit 1 as an example, the method specifically includes the following steps:

[0055] S101, controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach the zero position respectively based on the maximum driving frequency.

[0056] In this step, the first driving device and the second driving device are controlled to drive the first plunger and the second plunger to the zero position respectively based on the maximum driving frequency. Figure 2As shown, when the working state of each flow output is switched, it is necessary to first control the first drive device 11 and the second drive device 12 to quickly drive the first plunger 31 and the second plunger 32 to the zero position of the first plunger cavity 41 and the second plunger cavity 42 at the maximum drive frequency fmax, respectively. The zero position here refers to the midpoint of the stroke of the first plunger cavity 41 and the second plunger cavity 42, and fmax here is the maximum drive frequency allowed by the drive device.

[0057] S102, when the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the maximum drive frequency to achieve liquid discharge.

[0058] After controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to reach the zero position based on the maximum drive frequency through the above-mentioned step S101, in this step, when the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction, and after the liquid suction is completed, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move towards each other based on the maximum drive frequency to achieve liquid discharge.

[0059] Specifically, when the first plunger 31 and the second plunger 32 reach the zero position of the first plunger chamber 41 and the second plunger chamber 42 respectively, if the opposed direct-drive digital plunger pump needs to achieve full flow output, in response to the full flow output signal, the first drive device 11 and the second drive device 12 are controlled to drive the first plunger 31 and the second plunger 32 to move away from each other based on the maximum drive frequency fmax to achieve liquid suction. The drive stroke here is the length of the first plunger chamber 41 or the second plunger chamber 42. After the liquid suction is completed, the first drive device 11 and the second drive device 12 are controlled to drive the first plunger 31 and the second plunger 32 to move towards each other based on the maximum drive frequency to achieve liquid discharge, thereby achieving full flow output.

[0060] Specifically, after responding to the full flow output signal, as Figure 3 As shown in (a), the first driving device 11 and the second driving device 12 are driven by the first predetermined driving frequency fn1 respectively, and the first plunger 31 moves to Figure 3(a) in the left movement, the second plunger 32 moves to Figure 3 a moves to the right side, at this time, the first plunger chamber 41 and the second plunger chamber 42 are both in the liquid suction state, and at the same time, the liquid suction one-way valve 61 is controlled to open, and the liquid flows from the low-pressure circuit 2 and through the plunger chamber connecting channel 51 into the first plunger chamber 41 and the second plunger chamber 42 respectively.

[0061] like Figure 3 As shown in (b) of FIG. 1 , when the first plunger 31 and the second plunger 32 each reach the corresponding stroke end, the liquid absorption state ends, and then the first driving device 11 and the second driving device 12 change the driving direction, and drive the first plunger 31 to the maximum driving frequency fmax. Figure 3 b moves to the right, driving the second plunger 32 to Figure 3 b) the left side moves, at this time Figure 3 As shown in (c), the first plunger chamber 41 and the second plunger chamber 42 are both in a discharge state, and the discharge one-way valve 71 is controlled to open, so that liquid enters the high-pressure circuit 3 to achieve discharge.

[0062] This step can realize the full flow output of the opposed direct-drive digital plunger pump, wherein, assuming that the effective volume of the first plunger chamber 41 (the same as the second plunger chamber 41) is V, the output flow Q of the single liquid output unit is Q=120Vfmax, thereby realizing the full flow output of the opposed direct-drive digital plunger pump.

[0063] In addition, the flow control method further includes:

[0064] S103, when the first plunger and the second plunger reach the zero position, in response to the partial flow output signal, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move away from each other based on the first predetermined drive frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move towards each other based on the first predetermined drive frequency to achieve liquid discharge.

[0065] After controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to reach the zero position based on the maximum drive frequency through step S101, in this step, when the first plunger and the second plunger reach the zero position, in response to the partial flow output signal, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move away from each other based on the first predetermined drive frequency to achieve liquid suction, and after the liquid suction is completed, the first drive device and the second drive device are controlled to respectively drive the first plunger and the second plunger to move towards each other based on the first predetermined drive frequency to achieve liquid discharge.

[0066] Specifically, when the first plunger 31 and the second plunger 32 reach the zero position of the first plunger chamber 41 and the second plunger chamber 42 respectively, if the opposed direct-drive digital plunger pump needs to achieve full flow output, in response to the partial flow output signal and controlling the first drive device 11 and the second drive device 12 to drive the first plunger 31 and the second plunger 32 to move away from each other based on the first predetermined drive frequency fn1 to achieve liquid suction, where the drive stroke is set to the length of the first plunger chamber 41 or the second plunger chamber 42, after the liquid suction is completed, the first drive device 11 and the second drive device 12 are controlled to drive the first plunger 31 and the second plunger 32 to move towards each other based on the first predetermined drive frequency fn1 to achieve liquid discharge.

[0067] Specifically, after responding to the full flow output signal, as Figure 4 As shown in (a), the first driving device 11 and the second driving device 12 are driven by the first predetermined driving frequency fn1 respectively, and the first plunger 31 moves to Figure 4 (a) in the left movement, the second plunger 32 moves to Figure 4 The first plunger chamber 41 and the second plunger chamber 42 are both in the liquid suction state, and the liquid suction one-way valve 61 is controlled to open. The liquid flows from the low-pressure circuit 2 and through the plunger chamber connecting channel 51 into the first plunger chamber 41 and the second plunger chamber 42 respectively.

[0068] like Figure 4 As shown in (b) of FIG. 1 , when the first plunger 31 and the second plunger 32 each reach the corresponding stroke end, the liquid suction state ends, and then the first driving device 11 and the second driving device 12 change the driving direction, and drive the first plunger 31 to the first predetermined driving frequency fn1. Figure 4 (b) moves to the right, driving the second plunger 32 to Figure 4 In (b), the left side moves. Figure 4 As shown in (c), the first plunger chamber 41 and the second plunger chamber 42 are both in a discharge state, and the discharge one-way valve 71 is controlled to open, so that liquid enters the high-pressure circuit 3 to achieve discharge.

[0069] The value range of the first predetermined driving frequency fn here is fmax>fn1≥fmin, wherein fmin is the minimum driving frequency allowed by the driving device, and the driving stroke is set to the length of the corresponding plunger cavity.

[0070] This step can realize partial flow output of the opposed direct-drive digital plunger pump. The output flow Q of a single liquid output unit is Q=120Vfn1. The value of the first predetermined driving frequency fn1 is changed quickly and in real time according to the actual liquid supply demand. The partial flow output can be adjusted by controlling the driving frequency of the driving device. The adjustable flow range here is 120Vfmax>Q≥120Vfmin.

[0071] In addition, the flow control method further includes:

[0072] S104, when the first plunger and the second plunger reach the zero position, in response to the minimum flow output signal, the first drive device is controlled to drive the first plunger based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency; when the first plunger reaches the end of the stroke, the first drive device is controlled to drive the first plunger to move in the second direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the second direction based on the minimum drive frequency to achieve liquid discharge; when the first plunger and the second plunger reach the end of the stroke at the same time, the first drive device is controlled to drive the first plunger to move in the first direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency.

[0073] After controlling the first drive device and the second drive device to drive the first plunger and the second plunger to reach the zero position based on the maximum drive frequency respectively through step S101, in this step, when the first plunger and the second plunger reach the zero position, in response to the minimum flow output signal, the first drive device is controlled to drive the first plunger based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency; when the first plunger reaches the end of the stroke, the first drive device is controlled to drive the first plunger to move in the second direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger 32 to move in the second direction based on the minimum drive frequency and open the discharge one-way valve to achieve discharge; when the first plunger and the second plunger reach the end of the stroke at the same time, the first drive device is controlled to drive the first plunger to move in the first direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency.

[0074] Further, in the process of controlling the first driving device to drive the first plunger based on the second predetermined driving frequency and controlling the second driving device to drive the second plunger to move toward the first direction based on the minimum driving frequency, the liquid suction one-way valve is controlled to open.

[0075] The minimum flow range here refers to 120Vfmin>Q>0. Specifically, when the first plunger 31 and the second plunger 32 reach the zero position of the first plunger cavity 41 and the second plunger cavity 42 respectively, if the opposed direct-drive digital plunger pump is required to achieve a minimum flow output, in response to the minimum flow output signal, the first drive device 11 is controlled to drive the first drive plunger 31 to move to the first drive cavity 41 at a second predetermined drive frequency fn2. Figure 5 The left side movement in (a) of FIG. 1 is a left side movement, where the value range of fn2 is 2fmin>fn2>fmin, wherein fmin is the minimum driving frequency allowed by the driving device, and at the same time, the second driving device 12 is controlled to drive the second plunger 32 to move at the minimum driving frequency fmin. Figure 5 The left side movement in (a), that is, the movement directions of the first plunger 31 and the second plunger 32 are the same, but the driving frequencies are different.

[0076] The first plunger cavity 41 is in a liquid absorbing state, and the second plunger cavity 42 is in a liquid discharging state, and all the liquid in the second plunger cavity 42 flows into the first plunger cavity 41 through the plunger cavity connecting flow channel 51. Figure 5 As shown in (a), since the driving frequency of the first plunger 31 is greater than the driving frequency of the second plunger 32, the suction check valve 61 is controlled to open slightly to facilitate the suction of a small amount of liquid from the low-pressure circuit 2 into the first plunger chamber 41.

[0077] Furthermore, if Figure 5 As shown in (b) of FIG. 1 , since the driving frequency fn2 of the first plunger 31 is greater than the driving frequency fmin of the second plunger 32, the first plunger 31 will reach the end of the stroke of the first plunger cavity 41 faster than the second plunger 32. At this time, the second plunger 32 is still a certain distance away from the left end of the second plunger cavity 42. In this way, when the first plunger 31 reaches the left end of the first plunger cavity 41, the driving directions of the first driving device 11 and the second driving device 12 are changed at the same time, but the driving frequencies of each are kept unchanged. At this time, the first plunger 31 moves to the left end of the first plunger cavity 41 at the second predetermined driving frequency fn2. Figure 5 In (b), the second plunger 32 also moves to the right at the minimum driving frequency fmin. Figure 5 The first plunger cavity 41 is changed from the liquid absorbing state to the liquid discharging state, and the second plunger cavity 42 is changed from the liquid discharging state to the liquid absorbing state.

[0078] Here, since the driving frequency fn2 of the first plunger 31 is greater than the driving frequency fmin of the second plunger 32, as shown in FIG. Figure 5As shown in (c), the suction check valve 61 is controlled to be closed and the discharge check valve 71 is controlled to be opened, most of the liquid flows from the first plunger chamber 41 into the second plunger chamber 42 through the plunger connecting channel 51, and a small amount of liquid flows from the discharge check valve 71 into the high-pressure circuit 3. At this time, the output flow Q of the single liquid output unit is Q=120V(fn-fmin).

[0079] Furthermore, if Figure 5 As shown in (d) in FIG. 1 , when the first plunger 31 and the second plunger 32 simultaneously reach the right end of the first plunger cavity 41 and the right end of the second plunger cavity 42, the driving directions of the first driving device 11 and the second driving device 12 are changed again, and the first plunger 31 and the second plunger 32 keep the original driving frequency unchanged and move to the right end of the first plunger cavity 41 and the second plunger cavity 42 at the same time. Figure 5 The left movement in (e) starts the next cycle of suction and discharge process.

[0080] In this step, the value of the second predetermined driving frequency fn2 is changed according to the actual liquid supply demand, and the minimum flow output adjustment can be achieved by controlling the driving speed of the first driving device 11. Here, the adjustable flow range is 120Vfmin>Q>0.

[0081] S105, when the first plunger and the second plunger reach the zero position, in response to the zero flow output signal, the first driving device and the second driving device are controlled to drive the first plunger and the second plunger to move in the first direction respectively based on a third predetermined driving frequency.

[0082] After controlling the driving device to drive the first plunger and the second plunger to reach the zero position based on the maximum driving frequency through step S101, in this step, when the first plunger and the second plunger reach the zero position, in response to the zero flow output signal, the first driving device and the second driving device are controlled to drive the first plunger and the second plunger to move in the first direction respectively based on the third predetermined driving frequency.

[0083] like Figure 6 As shown in (a)-(c) in the figure, specifically, when the first plunger 31 and the second plunger 32 reach the zero position of the first plunger cavity 41 and the second plunger cavity 42 respectively, if the opposed direct-drive digital plunger pump is required to achieve zero flow output, in response to the zero flow output signal, the first drive device 11 and the second drive device 12 are controlled to drive the first plunger 31 and the second plunger 32 to move in the first direction based on the third predetermined drive frequency fn3, where the value range of fn3 is fmax≥fn3≥fmin. Considering the energy consumption problem, fn3 here can preferably be fn3=fmin.

[0084] Specifically, the first plunger 31 and the second plunger 32 simultaneously move Figure 6 The first plunger chamber 41 is in the state of absorbing liquid, and the second plunger chamber 42 is in the state of discharging liquid. Since the driving frequencies of the first plunger 31 and the second plunger 32 are the same, the fluid in the second plunger chamber 42 will all flow into the first plunger chamber 41 through the plunger chamber connecting flow channel 51, and the suction check valve 61 and the discharge check valve 71 are controlled to remain closed. At this time, the output flow rate Q of a single liquid output unit is 0.

[0085] When the liquid demand of the working scene changes, it is necessary to switch between different flow output states. At this time, it is only necessary to control the driving device to quickly return the two plungers to zero position at the maximum driving frequency fmax, and then adjust to the corresponding flow output state according to the liquid demand signal to quickly switch between the flow output states. Specifically, according to different liquid supply needs, the control device is used to correspondingly set the two plungers to face the same or opposite directions and reciprocate based on the same or different driving frequencies, so that all or part of the fluid flows alternately in the two plunger cavities through the plunger cavity connecting flow channel, thereby regulating the output flow of the high-pressure circuit.

[0086] Compared with the method of variable frequency motor speed regulation and adjusting the inclination angle of the swash plate, the embodiment disclosed in the present invention has a faster response speed for flow regulation and a larger flow variation range. In particular, it can realize the functions of extremely small flow output and zero flow output, thus solving the problem of limited variable range of existing direct-drive digital piston pumps.

[0087] The disclosed embodiment coordinates and controls the driving frequency and driving direction of two oppositely distributed driving devices through a digital control device, and then combines the connecting flow channel structure between the two plunger chambers to enable all or part of the fluid to flow alternately between the two plunger chambers, thereby being able to quickly adjust the total output flow in real time according to liquid demand, thereby being able to quickly switch between multiple flow output states to meet complex liquid usage scenarios such as intermittent liquid usage, full flow liquid usage, partial flow liquid usage, and extremely small flow liquid usage.

[0088] Based on the same inventive concept as the above-mentioned second embodiment, the third embodiment of the present disclosure provides a flow control device for an opposed direct-drive digital plunger pump, comprising:

[0089] A first control module, used for controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach a zero position respectively based on a maximum driving frequency;

[0090] The second control module is used for controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction after the first plunger and the second plunger reach the zero position in response to the full flow output signal, and controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to move towards each other based on the maximum drive frequency to achieve liquid discharge after the liquid suction is completed.

[0091] Furthermore, it also includes:

[0092] The third control module is used for controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to move away from each other based on a first predetermined driving frequency to achieve liquid suction after the first plunger and the second plunger reach the zero position in response to a partial flow output signal, and controlling the first drive device and the second drive device to respectively drive the first plunger and the second plunger to move toward each other based on the first predetermined driving frequency to achieve liquid discharge after the liquid suction is completed.

[0093] Furthermore, it also includes:

[0094] The fourth control module is used for, when the first plunger and the second plunger reach the zero position, in response to the minimum flow output signal, controlling the first drive device to drive the first plunger based on a second predetermined drive frequency and controlling the second drive device to drive the second plunger to move in the first direction based on a minimum drive frequency; when the first plunger reaches the end of the stroke, controlling the first drive device to drive the first plunger to move in the second direction based on the second predetermined drive frequency and controlling the second drive device to drive the second plunger to move in the second direction based on the minimum drive frequency to achieve liquid discharge; when the first plunger and the second plunger reach the end of the stroke at the same time, controlling the first drive device to drive the first plunger to move in the first direction based on the second predetermined drive frequency and controlling the second drive device to drive the second plunger to move in the first direction based on the minimum drive frequency.

[0095] Furthermore, it also includes:

[0096] The fifth control module controls the first driving device and the second driving device to drive the first plunger and the second plunger to move in the first direction based on a third predetermined driving frequency respectively in response to the zero flow output signal after the first plunger and the second plunger reach the zero position.

[0097] The disclosed embodiment coordinates and controls the driving frequency and driving direction of two oppositely distributed driving devices through a digital control device, and then combines the connecting flow channel structure between the two plunger chambers to enable all or part of the fluid to flow alternately between the two plunger chambers, thereby being able to quickly adjust the total output flow in real time according to liquid demand, thereby being able to quickly switch between multiple flow output states to meet complex liquid usage scenarios such as intermittent liquid usage, full flow liquid usage, partial flow liquid usage, and extremely small flow liquid usage.

[0098] A fourth embodiment of the present disclosure provides a storage medium storing a computer program. When the computer program is executed by a processor, the steps of implementing the above control method include:

[0099] S11, controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach a zero position respectively based on a maximum driving frequency;

[0100] S12, when the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the maximum drive frequency to achieve liquid discharge.

[0101] Of course, other steps of the control method can also be used to implement the above embodiment.

[0102] The disclosed embodiment coordinates and controls the driving frequency and driving direction of two oppositely distributed driving devices through a digital control device, and then combines the connecting flow channel structure between the two plunger chambers to enable all or part of the fluid to flow alternately between the two plunger chambers, thereby being able to quickly adjust the total output flow in real time according to liquid demand, thereby being able to quickly switch between multiple flow output states to meet complex liquid usage scenarios such as intermittent liquid usage, full flow liquid usage, partial flow liquid usage, and extremely small flow liquid usage.

[0103] A fifth embodiment of the present disclosure provides an electronic device, the electronic device comprising at least a memory and a processor, the memory storing a computer program, and the processor implementing the steps of the above control method when executing the computer program on the memory, specifically comprising:

[0104] S21, controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach the zero position respectively based on the maximum driving frequency;

[0105] S22, when the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the maximum drive frequency to achieve liquid discharge.

[0106] The disclosed embodiment coordinates and controls the driving frequency and driving direction of two oppositely distributed driving devices through a digital control device, and then combines the connecting flow channel structure between the two plunger chambers to enable all or part of the fluid to flow alternately between the two plunger chambers, thereby being able to quickly adjust the total output flow in real time according to liquid demand, thereby being able to quickly switch between multiple flow output states to meet complex liquid usage scenarios such as intermittent liquid usage, full flow liquid usage, partial flow liquid usage, and extremely small flow liquid usage.

[0107] The technicians in the relevant field can clearly understand that for the convenience and simplicity of description, only the division of the above-mentioned functional units and modules is used as an example for illustration. In practical applications, the above-mentioned function allocation can be completed by different functional units and modules as needed, that is, the internal structure of the device can be divided into different functional units or modules to complete all or part of the functions described above. The functional units and modules in the embodiment can be integrated in a processing unit, or each unit can exist physically separately, or two or more units can be integrated in one unit. The above-mentioned integrated unit can be implemented in the form of hardware or in the form of software functional units. In addition, the specific names of the functional units and modules are only for the convenience of distinguishing each other, and are not used to limit the scope of protection of this application. The specific working process of the units and modules in the above-mentioned system can refer to the corresponding process in the aforementioned method embodiment, which will not be repeated here.

[0108] In the above embodiments, the description of each embodiment has its own emphasis. For parts that are not described or recorded in detail in a certain embodiment, reference can be made to the relevant descriptions of other embodiments.

[0109] Those of ordinary skill in the art will appreciate that the units and algorithm steps of each example described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, or a combination of computer software and electronic hardware. Whether these functions are performed in hardware or software depends on the specific application and design constraints of the technical solution. Professional and technical personnel can use different methods to implement the described functions for each specific application, but such implementation should not be considered to be beyond the scope of this application.

[0110] In the embodiments provided in the present application, it should be understood that the disclosed devices / terminal equipment and methods can be implemented in other ways. For example, the device / terminal equipment embodiments described above are only schematic. For example, the division of the modules or units is only a logical function division. There may be other division methods in actual implementation, such as multiple units or components can be combined or integrated into another system, or some features can be ignored or not executed. Another point is that the mutual coupling or direct coupling or communication connection shown or discussed can be through some interfaces, indirect coupling or communication connection of devices or units, which can be electrical, mechanical or other forms.

[0111] The units described as separate components may or may not be physically separated, and the components shown as units may or may not be physical units, that is, they may be located in one place or distributed on multiple network units. Some or all of the units may be selected according to actual needs to achieve the purpose of the solution of this embodiment.

[0112] In addition, each functional unit in each embodiment of the present application may be integrated into one processing unit, or each unit may exist physically separately, or two or more units may be integrated into one unit. The above-mentioned integrated unit may be implemented in the form of hardware or in the form of software functional units.

[0113] If the integrated module is implemented in the form of a software functional unit and sold or used as an independent product, it can be stored in a computer-readable storage medium. Based on this understanding, the present application implements all or part of the processes in the above-mentioned embodiment method, and can also be completed by instructing the relevant hardware through a computer program. The computer program can be stored in a computer-readable storage medium. When the computer program is executed by the processor, the steps of the above-mentioned motor torque control method embodiments can be implemented. Among them, the computer program includes computer program code, and the computer program code can be in source code form, object code form, executable file or some intermediate form. The computer-readable medium may include: any entity or device capable of carrying the computer program code, recording medium, U disk, mobile hard disk, disk, optical disk, computer memory, read-only memory (ROM, Read-Only Memory), random access memory (RAM, Random Access Memory), electric carrier signal, telecommunication signal and software distribution medium. It should be noted that the content contained in the computer-readable medium can be appropriately increased or decreased according to the requirements of legislation and patent practice in the jurisdiction. For example, in some jurisdictions, according to legislation and patent practice, computer-readable media do not include electric carrier signals and telecommunication signals.

[0114] In addition, the features of the embodiments shown in the drawings of the present application or the various embodiments mentioned in this specification are not necessarily understood as independent embodiments. Instead, each feature described in one example of an embodiment can be combined with one or more other desired features from other embodiments to produce other embodiments not described in words or with reference to the drawings.

[0115] The embodiments described above are only used to illustrate the technical solutions of the present application, rather than to limit them. Although the present application has been described in detail with reference to the aforementioned embodiments, a person skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. Such modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present application, and should all be included in the protection scope of the present application.

Claims

1. An opposed direct-drive digital piston pump, characterized in that: It comprises a control device and at least one liquid output unit, wherein the control device is used to regulate the total output flow of the liquid output unit to adapt to at least one output state of full flow output, partial flow output, very little flow output and zero flow output.

2. The opposed direct-drive digital plunger pump according to claim 1, characterized in that: There are multiple liquid output units, and the multiple liquid output units are arranged in sequence according to a predetermined order.

3. The opposed direct-drive digital plunger pump according to claim 1, characterized in that: The liquid output unit includes a control unit and a first plunger cavity and a second plunger cavity that are interconnected and arranged opposite to each other. The control unit is connected to the control device. The first plunger cavity and the second plunger cavity are communicated with each other through a plunger cavity connecting channel. A movable first plunger and a movable second plunger are respectively arranged in the first plunger cavity and the second plunger cavity. The first plunger is connected to a first driving device through a first plunger rod, and the second plunger is connected to a second driving device through a second plunger rod.

4. The opposed direct-drive digital piston pump according to claim 3, characterized in that: The first driving device and / or the second driving device is an electro-hydraulic actuator or a motor.

5. The opposed direct-drive digital plunger pump according to claim 3, characterized in that: The plunger cavity connecting flow channel is connected to the low-pressure circuit through the first flow channel, and the plunger cavity connecting flow channel is also connected to the high-pressure circuit through the second flow channel.

6. The opposed direct-drive digital piston pump according to claim 5, characterized in that: A liquid suction one-way valve is arranged on the first flow channel, and a liquid discharge one-way valve is arranged on the second flow channel.

7. A flow control method for an opposed direct-drive digital plunger pump, characterized in that: include: Controlling the first driving device and the second driving device to drive the first plunger and the second plunger to reach the zero position respectively based on the maximum driving frequency; When the first plunger and the second plunger reach the zero position, in response to the full flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on the maximum drive frequency to achieve liquid suction. After the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the maximum drive frequency to achieve liquid discharge.

8. The flow control method according to claim 7, characterized in that: Also includes: When the first plunger and the second plunger reach the zero position, in response to the partial flow output signal, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move away from each other based on a first predetermined driving frequency to achieve liquid suction; after the liquid suction is completed, the first drive device and the second drive device are controlled to drive the first plunger and the second plunger to move toward each other based on the first predetermined driving frequency to achieve liquid discharge.

9. The flow control method according to claim 8, characterized in that: Also includes: When the first plunger and the second plunger reach the zero position, in response to the minimum flow output signal, the first drive device is controlled to drive the first plunger based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency; when the first plunger reaches the end of the stroke, the first drive device is controlled to drive the first plunger to move in the second direction based on the second predetermined drive frequency, and the second drive device is controlled to drive the second plunger to move in the second direction based on the minimum drive frequency to achieve liquid discharge; when the first plunger and the second plunger reach the end of the stroke at the same time, the first drive device is controlled to drive the first plunger to move in the first direction based on the second predetermined drive frequency and the second drive device is controlled to drive the second plunger to move in the first direction based on the minimum drive frequency.

10. The flow control method according to claim 9, characterized in that: Also includes: When the first plunger and the second plunger reach the zero position, in response to the zero flow output signal, the first driving device and the second driving device are controlled to drive the first plunger and the second plunger to move in the first direction based on a third predetermined driving frequency.

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