Digital valve

Abstract

The application discloses a digital valve, which comprises a main valve output part, a pilot control part, a feedback mechanism, a main liquid supply path and a main liquid return path. The main valve output part comprises a main valve body and a main valve core, and the main valve core is located inside the main valve body. The pilot control part comprises a pilot valve body, a pilot valve core and a driving mechanism. The driving mechanism is connected in transmission with the pilot valve core in the pilot valve body, and adjusts the position of the pilot valve core in the pilot valve body. The feedback mechanism comprises a first feedback connecting rod, a second feedback connecting rod and a turning part. The pilot valve core is connected with the first feedback connecting rod, the main valve core is connected with the second feedback connecting rod, and the first feedback connecting rod and the second feedback connecting rod are connected in transmission with the turning part. The main liquid supply path and the main liquid return path are connected in communication with the pilot valve body and the main valve body respectively. The digital valve provided by the application has the advantages of good linearity and timely feedback.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of valves, in particular to a digital valve. BACKGROUND

[0002] The electro-hydraulic proportional valve is a kind of hydraulic valve between on-off hydraulic valve and servo valve, which can continuously control the pressure, flow and other parameters of the hydraulic system according to the input signal, and make it proportional to the input signal. The proportional valve or pilot proportional valve on the market currently relies on proportional electromagnet to drive the valve core. The magnetic attraction of the proportional electromagnet is affected by the position, which causes the force to be uneven when the valve core moves to a new position, resulting in poor linearity of the proportional valve. In the related technology, the position feedback of the proportional valve is mainly to detect the position of the valve core by a sensor, and to control the power of the proportional electromagnet by electric-hydraulic feedback. This electric-hydraulic feedback method has a certain signal delay, which reduces the control accuracy of the proportional valve. With the popularization of electronic information technology in the field of hydraulic transmission, the traditional hydraulic control system has problems such as sensitivity to pollution, low efficiency, and easy to be disturbed. Digital hydraulic technology has strong advantages in response speed, anti-interference, energy saving, fault tolerance and universality. Especially, the control form of digital signal is more simple and meets the information interface requirements of computers, Internet and other information interfaces, which can reduce the precision loss, time delay and cost increase caused by A / D and D / A conversion. Therefore, the modern digital hydraulic technology has been widely concerned since it was proposed, and it is called the future hydraulic technology. SUMMARY

[0003] The present application aims to at least solve one of the technical problems in the related art. To this end, an embodiment of the present application provides a digital valve, which has the advantages of good linearity and timely feedback.

[0004] The digital valve according to the embodiment of the present application, the digital valve comprises a main valve output part, a pilot control part, a feedback mechanism, a main liquid supply path and a main liquid return path, the main valve output part comprises a main valve body and a main valve core, the main valve core is located inside the main valve body, the pilot control part comprises a pilot valve body, a pilot valve core and a driving mechanism, the driving mechanism is connected in transmission with the pilot valve core in the pilot valve body, the driving mechanism adjusts the position of the pilot valve core in the pilot valve body, the feedback mechanism comprises a first feedback connecting rod, a second feedback connecting rod and a turning piece, the pilot valve core is connected with the first feedback connecting rod, the main valve core is connected with the second feedback connecting rod, the first feedback connecting rod and the second feedback connecting rod are connected in transmission with the turning piece, and the main liquid supply path and the main liquid return path are connected in communication with the pilot valve body and the main valve body respectively.

[0005] The digital valve according to the embodiment of the present application has the advantages of good linearity and timely feedback.

[0006] In some embodiments, the main valve body has control port C2, oil outlet port T port, A cavity, oil inlet port P port, B cavity and control port D2 in sequence, and the pilot valve body has oil outlet port T port, control port C1, oil inlet port P port and control port D1 in sequence, the main liquid supply path connects the P port of the main valve body and the P port of the pilot valve body, the main liquid return path connects the T port of the main valve body and the T port of the pilot valve body, the control port C1 communicates with the control port C2, and the control port D1 communicates with the control port D2.

[0007] In some embodiments, when the pilot valve core is located at the middle position of the pilot valve body, the pilot valve core closes the control port C1 and the control port D1 cavity of the pilot valve body.

[0008] In some embodiments, a damping screw plug is arranged on the pipeline between the control port C1 and the control port C2 and between the control port D1 and the control port D2.

[0009] In some embodiments, the driving mechanism includes a stepper motor, a shaft coupling and a guide screw nut, the output end of the stepper motor is connected with the guide screw nut through the shaft coupling, and the guide screw nut is connected with the pilot valve core through a guide screw.

[0010] In some embodiments, the pilot valve body is provided with end covers at both ends, the guide screw passes through the end covers and is connected with the pilot valve core, and the end of the pilot valve core away from the guide screw is connected with the first feedback connecting rod.

[0011] In some embodiments, the steering member includes a screw nut and a sprocket, the first feedback connecting rod is connected with the first end of the sprocket through a screw nut, and the second feedback connecting rod is connected with the second end of the sprocket through a screw nut.

[0012] In some embodiments, the steering member includes a first steering gear, a second steering gear and a third steering gear, the first feedback connecting rod is connected with the first steering gear through a screw nut, the second feedback connecting rod is connected with the second steering gear through a screw nut, and the third steering gear is arranged between the first steering gear and the second steering gear and is engaged with the first steering gear and the second steering gear.

[0013] In some embodiments, the steering member includes a first bevel gear arranged on the first feedback connecting rod, a second bevel gear arranged on the second feedback connecting rod and a steering rod, the small end of the first bevel gear is adjacent to the small end of the second bevel gear, and the two ends of the steering rod are provided with third bevel gears, and the third bevel gears are engaged with the first bevel gear and the second bevel gear respectively.

[0014] In some embodiments, the steering member comprises a differential lever, the driving mechanism comprises a stepper motor and a lead screw nut, the output end of the stepper motor is connected with the lead screw nut through a shaft coupling, the first end of the differential lever is pivotally connected with the nut of the lead screw nut, the second end of the differential lever is pivotally connected with a second feedback connecting rod, and the first feedback connecting rod is pivotally connected with the middle part of the differential lever. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of a digital valve according to an embodiment of the present application.

[0016] Figure 2 is a structural schematic diagram of a digital valve according to another embodiment of the present application.

[0017] Figure 3 is a structural schematic diagram of a digital valve according to another embodiment of the present application.

[0018] Figure 4 is a structural schematic diagram of a digital valve according to another embodiment of the present application.

[0019] Figure 5 is a schematic diagram of the use state of a steering member of a digital valve according to another embodiment of the present application.

[0020] Figure 6 is a schematic diagram of the pressure moving state of a main valve core of a digital valve according to an embodiment of the present application.

[0021] Reference signs: 1, driving mechanism; 2, shaft coupling; 3, lead screw nut; 4, pilot valve end cover; 5, sealing ring baffle; 6, sealing ring; 7, pilot valve core; 8, centering spring; 9, guide cylinder; 10, first feedback connecting rod; 11, second feedback connecting rod; 12, differential lever; 13, main valve core; 14, main valve body; 15, damping screw plug; 16, steering member. DETAILED DESCRIPTION

[0022] Embodiments of the present application are described in detail below, examples of which are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to explain the present application, and cannot be understood as a limitation of the present application.

[0023] The digital valve is a stepper motor or a servo motor controlled by a digital signal, which is used as an electric-mechanical conversion element, and the rotation angle of the motor is converted into the linear opening of the valve core by a lead screw structure. Such a valve has the advantages of high repeatability, no hysteresis, and no need for D / A conversion and linear amplifiers, which is more conducive to the digital control and intelligent development of the hydraulic system.

[0024] As Figures 1 to 6As shown, the digital valve according to the embodiment of the present application comprises a main valve output part, a pilot control part, a feedback mechanism, a main liquid supply path and a main liquid return path. The main valve output part comprises a main valve body 14 and a main valve core 13, and the main valve core 13 is located inside the main valve body 14. The pilot control part comprises a pilot valve body, a pilot valve core 7 and a driving mechanism 1. The driving mechanism 1 is in transmission connection with the pilot valve core 7 in the pilot valve body. The driving mechanism 1 adjusts the position of the pilot valve core 7 in the pilot valve body. The feedback mechanism comprises a first feedback connecting rod 10, a second feedback connecting rod 11 and a turning piece 16. The pilot valve core 7 is connected with the first feedback connecting rod 10, and the main valve core 13 is connected with the second feedback connecting rod 11. The first feedback connecting rod 10 and the second feedback connecting rod 11 are in transmission connection with the turning piece 16. The main liquid supply path and the main liquid return path are connected with the pilot valve body and the main valve body 14 respectively. The first feedback connecting rod 10 is sleeved with a guide cylinder 9, and the guide cylinder 9 restricts the movement of the first feedback connecting rod 10 to keep the axial direction translation. The guide cylinder 9 is fixedly connected with the end cover 4 of the pilot valve body. Adjusting the position of the pilot valve core 7 in the pilot valve body can change the pressure on both sides of the main valve core 13 to change the opening of the main valve core 13. Adjusting the opening of the pilot valve core 7 by the driving mechanism 1 can realize the proportional adjustment and reversing of the pilot valve control main valve path, and realize the control of the hydraulic system pressure and flow. The main valve core 13 moves at the same time to feedback the pilot valve through the feedback mechanism. In the case of different control signals, the specific opening of the valve core is realized. The driving mechanism 1 can be driven by a stepping motor or a servo motor, which can realize the proportional control of the hydraulic system loop of the digital valve, realize the digitization of the control signal, reduce the control difficulty of the electro-hydraulic servo, and adjust the pilot valve core 7 and the main valve core 13 through the feedback mechanism. The valve core has good linearity and small hydraulic impact.

[0025] The digital valve according to the embodiment of the present application has the advantages of good linearity and timely feedback.

[0026] In some embodiments, as shown in Figure 1 and Figure 6 The main valve body 14 has a control port C2, an oil outlet T port, an A cavity, an oil inlet P port, a B cavity and a control port D2 in sequence. Correspondingly, the pilot valve body has an oil outlet T port, a control port C1, an oil inlet P port and a control port D1 in sequence. The main liquid supply path connects the P port of the main valve body 14 and the P port of the pilot valve body. The main liquid return path connects the T port of the main valve body 14 and the T port of the pilot valve body. The control port C1 and the control port C2 are in communication. The control port D1 and the control port D2 are in communication.

[0027] Specifically, in the axial direction of the spool of the pilot valve, the spool moves left or right to connect one working oil port with one oil outlet, the main spool 13 in the main valve body 14 has two protrusions for closing the A cavity and the B cavity respectively, the pilot spool 7 has a protrusion for closing the P port, the two ends of the pilot valve are used to close the control port C1 and the control port D1, the movement of the main spool 13 in the main valve body 14 can move the protrusions to open the cavity, and the movement of the pilot spool 7 in the pilot valve body can connect the P port of the high-pressure oil way with the control port C1.

[0028] In some embodiments, as shown in Figure 1 When the pilot spool 7 is in the middle position of the pilot valve body, the pilot spool 7 closes the control port C1 and the control port D1 cavities of the pilot valve body.

[0029] Specifically, when the pilot spool 7 of the pilot valve is in the middle position, the protrusion of the pilot spool 7 closes the P port, and at this time the main spool 13 is also in the middle position of the main valve body 14.

[0030] In some embodiments, as shown in Figure 1 A damping screw plug 15 is arranged on the pipeline between the control port C1 and the control port C2 and between the control port D1 and the control port D2.

[0031] Specifically, the damping screw plug 15 has a damping hole inside, and the damping screw plug 15 placed in the pipeline can adjust the flow and pressure of the pipeline.

[0032] In some embodiments, as shown in Figures 1 to 4 The driving mechanism 1 includes a stepping motor, a shaft coupling 2 and a guide screw nut 3, the output end of the stepping motor is connected with the guide screw nut 3 through the shaft coupling 2, and the guide screw nut 3 is connected with the pilot spool 7 through a guide screw.

[0033] Specifically, the driving mechanism 1 drives the guide screw through the stepping motor to drive the pilot spool 7 to move, which can realize the digitization of the control signal and reduce the control difficulty of the electro-hydraulic servo. The structure of the guide screw nut 3 can make the pilot spool 7 have better moving precision and reduce hydraulic impact.

[0034] In some embodiments, as shown in Figures 1 to 3 The two ends of the pilot valve body are provided with end covers 4, the guide screw passes through the end covers 4 and is connected with the pilot spool 7, and the end of the pilot spool 7 away from the guide screw is connected with a first feedback connecting rod 10.

[0035] Specifically, the end cover 4 at both ends of the pilot valve is fixed in cooperation with the guide screw nut 3, the end cover 4 is provided with a sealing ring 6 and a sealing ring 6 baffle 5 between the pilot valve body, the sealing ring 6 baffle 5 is used to limit the sealing ring 6 to prevent the sealing ring 6 from moving, the sealing ring 6 baffle 5 is attached to the guide nut, the pilot valve core 7 is provided with a centering spring 8, the centering spring 8 is connected with the end cover 4, and when the driving mechanism 1 is not working, the centering spring 8 can automatically push the pilot valve core 7 to reset to the middle position of the pilot valve body.

[0036] In some embodiments, as shown in Figure 1 The turning piece 16 includes a screw nut and a sprocket, the first feedback link 10 is connected with the first end of the sprocket through the screw nut, and the second feedback link 11 is connected with the second end of the sprocket through the screw nut.

[0037] Specifically, the first feedback link 10 is connected with the nut of the screw nut, the nut is provided with a non-self-locking internal thread, the screw passes through the first end of the sprocket to drive the sprocket to rotate, the second segment of the sprocket is provided with a screw, the screw is threadedly connected with the nut, the nut is connected with the second feedback link 11, when the pilot valve body moves to the first feedback link 10, the high-pressure oil path is communicated with the control port C1 and the control port C2, so that the main valve core 13 is unbalanced in force and moves to the second feedback link 11, the main valve core 13 moves while driving the second feedback link 11 to move, the second feedback link 11 drives the screw to rotate in the opposite direction to drive the pilot valve core 7 to reset. After the driving signal of the driving mechanism 1, the main valve core 13 is in a balanced state again after the pilot valve core 7 is reset, and the closed-loop position feedback is completed.

[0038] In some embodiments, as shown in Figure 2 The turning piece 16 includes a first turning gear, a second turning gear and a third turning gear, the first feedback link 10 is connected with the first turning gear through the screw nut, the second feedback link 11 is connected with the second turning gear through the screw nut, and the third turning gear is arranged between the first turning gear and the second turning gear and is engaged with the first turning gear and the second turning gear. The rotation axes of the first turning gear, the second turning gear and the third turning gear are parallel to each other.

[0039] Thus, the mechanical feedback of the feedback mechanism is realized by the transmission of the three gears to make the pilot valve core 7 realize closed-loop position feedback.

[0040] In some embodiments, as shown in Figure 3As shown, the steering member 16 comprises a first bevel gear provided on the first feedback link 10, a second bevel gear provided on the second feedback link 11, and a steering rod, the small end of the first bevel gear is adjacent to the small end of the second bevel gear, and the steering rod is provided with a third bevel gear at both ends, and the third bevel gears are respectively engaged with the first bevel gear and the second bevel gear. The two third bevel gears at both ends of the steering rod are symmetrical about the steering rod, the steering rod rotates relative to the valve body of the digital valve, and the axial direction of the steering rod is perpendicular to the first feedback link 10 and the second feedback link 11.

[0041] Thus, the mechanical feedback of the feedback mechanism is realized by the cooperation of multiple bevel gears to drive the pilot spool 7 to close-loop position feedback.

[0042] In some embodiments, as shown in Figure 4 and Figure 5 As shown, the steering member 16 comprises a differential rod 12, the driving mechanism 1 comprises a stepper motor and a guide screw nut 3, the output end of the stepper motor is connected with the guide screw nut 3 through a shaft coupling 2, the first end of the differential rod 12 is pivotably connected with the nut of the guide screw nut 3, the second end of the differential rod 12 is pivotably connected with the second feedback link 11, and the first feedback link 10 is pivotably connected with the middle part of the differential rod 12.

[0043] Specifically, the stepper motor is fixed on the side of the pilot valve body away from the main valve body 14, the guide screw is rotatably connected with the valve body of the digital valve, the nut of the guide screw nut 3 is hinged with the first end of the differential rod 12, the second end of the differential rod 12 is rotatably connected with the second feedback link 11, and the first feedback link 10 is rotatably connected with the middle part of the differential rod 12.

[0044] In the description of the present application, it should be understood that the terms "center", "longitudinal", "transverse", "length", "width", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", "clockwise", "counterclockwise", "axial", "radial", "circumferential" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and therefore cannot be understood as indicating or implying that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as limiting the present application.

[0045] In addition, the terms "first", "second" are only for descriptive purposes, and cannot be understood as indicating or implying relative importance or implicitly indicating the number of the technical features indicated. Therefore, the features defined with "first", "second" can explicitly or implicitly include at least one of the features. In the description of the present application, the meaning of "multiple" is at least two, such as two, three, etc., unless otherwise explicitly specified.

[0046] In the present application, unless specifically defined otherwise, the terms "mount", "connected", "connecting", "fixed", "unfixed", and the like are to be construed in their broadest possible sense, such as, for example, fixedly connected, detachably connected, or integral; mechanically connected, electrically connected, or communicatively connected; directly connected, or indirectly connected via intervening medium; or internal communication between elements, or interaction between elements, unless specifically defined otherwise. The specific meaning of the above terms in the present application can be understood according to the specific circumstances by those of ordinary skill in the art.

[0047] In the present application, unless specifically defined otherwise, a first feature "on", "above", or "over" a second feature can be direct contact between the first and second features, or indirect contact between the first and second features via intervening medium. Furthermore, the first feature "above", "over", and "on top of" the second feature can be directly above or obliquely above the second feature, or simply indicate that the first feature is at a higher horizontal level than the second feature. The first feature "below", "under", and "underneath" the second feature can be directly below or obliquely below the second feature, or simply indicate that the first feature is at a lower horizontal level than the second feature.

[0048] In the present application, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" mean that the particular feature, structure, material, or characteristic being described is included in at least one embodiment or example of the present application. The illustrative appearances of the above terms in various places in the specification are not necessarily referring to the same embodiment or example. Furthermore, the particular features, structures, materials, or characteristics can be combined in any suitable manner in one or more embodiments or examples. In addition, the terms "comprising", "including", "containing", and "consisting" and their variations are intended to be accorded the broadest possible interpretation to encompass all the features that they mean, including the possibility of equivalence. It is intended that the application have as broad a scope as possible with respect to the subject matter recited in each of the claims below.

[0049] Although embodiments of the present application have been shown and described above, it is to be understood that the above embodiments are merely exemplary, and are not to be taken as limiting the present application. Those of ordinary skill in the art can make changes, modifications, replacements, and variations to the above embodiments within the scope of the present application.

Claims

1. A digital valve, characterized in that, include: The main valve output section includes a main valve body and a main valve core, wherein the main valve core is located inside the main valve body. A pilot control unit, comprising a pilot valve body, a pilot valve core, and a drive mechanism, wherein the drive mechanism is throttlely connected to the pilot valve core within the pilot valve body, and the drive mechanism adjusts the position of the pilot valve core within the pilot valve body; The feedback mechanism includes a first feedback link, a second feedback link, and a steering component. The pilot valve core is connected to the first feedback link, the main valve core is connected to the second feedback link, and the first feedback link and the second feedback link are connected to the steering component in a transmission manner. The main supply line and the main return line connect the pilot valve body and the main valve body respectively. The drive mechanism includes a stepper motor, a coupling, and a guide screw nut. The output end of the stepper motor is connected to the guide screw nut via the coupling, and the guide screw nut is connected to the pilot valve core via the guide screw. The steering component includes a lead screw nut and a sprocket. The first feedback link is connected to the first end of the sprocket via the lead screw nut, and the second feedback link is connected to the second end of the sprocket via another lead screw nut. The first feedback link is connected to the nut of the lead screw nut, which has a non-self-locking internal thread. The lead screw passes through the first end of the sprocket and drives the sprocket to rotate. The second end of the sprocket is connected to another lead screw, which is threadedly connected to another nut. The other nut is connected to the second feedback link. Alternatively, the steering component includes a first steering gear, a second steering gear, and a third steering gear. The first feedback link is connected to the first steering gear via a lead screw nut, the second feedback link is connected to the second steering gear via another lead screw nut, and the third steering gear is disposed between the first steering gear and the second steering gear and meshes with the first steering gear and the second steering gear. Alternatively, the steering component includes a first bevel gear on the first feedback link, a second bevel gear on the second feedback link, and a steering rod. The small end of the first bevel gear is adjacent to the small end of the second bevel gear. The steering rod has third bevel gears at both ends, which mesh with the first bevel gear and the second bevel gear respectively. The first feedback link is connected to the first bevel gear through a lead screw nut, and the second feedback link is connected to the second bevel gear through another lead screw nut.

2. The digital valve according to claim 1, characterized in that, The main valve body has a control port C2, an oil outlet T port, a cavity A, an oil inlet P port, a cavity B, and a control port D2 in sequence. Correspondingly, the pilot valve body has an oil outlet T port, a control port C1, an oil inlet P port, and a control port D1 in sequence. The main fluid supply circuit is connected to the P port of the main valve body and the P port of the pilot valve body. The main fluid return circuit is connected to the T port of the main valve body and the T port of the pilot valve body. Control port C1 is connected to control port C2, and control port D1 is connected to control port D2.

3. The digital valve according to claim 2, characterized in that, When the pilot valve core is in the middle position of the pilot valve body, the pilot valve core closes the control port C1 and control port D1 cavities of the pilot valve body.

4. The digital valve according to claim 2, characterized in that, Damping plugs are installed on the pipelines between control ports C1 and C2 and between control ports D1 and D2.

5. The digital valve according to claim 1, characterized in that, The pilot valve body has end caps at both ends, the guide screw passes through the end caps and is connected to the pilot valve core, and the end of the pilot valve core away from the guide screw is connected to the first feedback link.

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