A hydraulic device and digital hydraulic cylinder with mechanical position pilot feedback

Abstract

The present invention proposes a hydraulic device and a digital hydraulic cylinder with mechanical position pilot feedback, the hydraulic device includes: a pilot valve, a hydraulic cylinder and a transmission member, the pilot valve includes a first valve body and a first valve core, the first valve core is inserted on the first valve body, and the first valve core is movable along the axis of the first valve core, the hydraulic cylinder includes a cylinder body and a piston rod, the first end of the piston rod is located in the cylinder body and is movable along the extension direction of the cylinder body, the second end of the piston rod is located outside the cylinder body, the pilot valve is connected to the hydraulic cylinder to drive the piston rod to move, the first end of the transmission member is connected to the first end of the first valve core, the second end of the transmission member is connected to the first end of the piston rod, the pilot valve is used to drive the piston rod to move along the axial direction of the piston rod, and the movement of the piston rod is used to drive the first valve core to move along the axial direction of the first valve core. The hydraulic device with mechanical position pilot feedback of the present invention has the advantages of high control accuracy and fast response speed.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic systems, and in particular to a hydraulic device and a digital hydraulic cylinder with mechanical position pilot feedback. Background Art

[0002] With the promotion of electronic information technology in the field of hydraulic transmission, the problems of traditional hydraulic control systems such as sensitivity to pollution, low efficiency and susceptibility to interference have become increasingly prominent. Digital hydraulic technology has shown strong advantages in response speed, anti-interference, energy saving, fault tolerance, and versatility. In particular, the control form of digital signals is simpler and meets the requirements of information interfaces such as computers and the Internet. It can reduce the accuracy loss, time delay and cost increase caused by A / D and D / A conversion. Therefore, digital hydraulics in the modern sense have received widespread attention once proposed and are called the future hydraulic technology.

[0003] Digital valves use stepper motors or servo motors controlled by digital signals as electro-mechanical conversion elements, and rely on the screw structure to convert the motor's rotation angle into the linear opening of the valve core. This type of 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 hydraulic systems.

[0004] In the related art, sensors are generally used to detect the position of the valve core and provide position feedback, and electro-hydraulic feedback is used to control the output of the proportional solenoid on the valve core. However, this electro-hydraulic feedback method has a certain signal delay, which will reduce the control accuracy of the valve core. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent.

[0006] To this end, an embodiment of the present invention provides a hydraulic device with mechanical position pilot feedback, which has the advantages of high control accuracy and fast response speed.

[0007] An embodiment of the present invention provides a digital hydraulic cylinder, which has the advantages of high control accuracy and fast response speed.

[0008] The hydraulic device with mechanical position pilot feedback according to the embodiment of the present invention comprises:

[0009] A pilot valve, the pilot valve comprising a first valve body and a first valve core, the first valve core is inserted into the first valve body, and the first valve core is movable along the axis of the first valve core;

[0010] A hydraulic cylinder, the hydraulic cylinder comprising a cylinder body and a piston rod, the first end of the piston rod is located in the cylinder body and is movable along the extension direction of the cylinder body, the second end of the piston rod is located outside the cylinder body, and the pilot valve is connected to the hydraulic cylinder to drive the piston rod to move;

[0011] A transmission member, wherein the first end of the transmission member is connected to the first end of the first valve core, the second end of the transmission member is connected to the first end of the piston rod, the pilot valve is used to drive the piston rod to move axially along the piston rod, and the movement of the piston rod is used to drive the first valve core to move axially along the first valve core.

[0012] The hydraulic device with mechanical position pilot feedback in the embodiment of the present invention can use a transmission member to mechanically connect the first valve core and the piston rod, so that after the piston rod is actuated, the displacement information of the piston rod can be transmitted to the first valve core by mechanical feedback to improve the control accuracy of the hydraulic device.

[0013] In addition, the transmission member can also provide mechanical feedback to the first valve core after the piston rod is actuated, so that the first valve core can respond in time, thereby improving the response speed of the hydraulic device with mechanical position pilot feedback in the embodiment of the present invention.

[0014] Therefore, the hydraulic device with mechanical position pilot feedback in the embodiment of the present invention has the advantages of high control accuracy and fast response speed.

[0015] In some embodiments, the first valve core is movable between a first direction and a second direction to drive the piston rod to move between a third direction and a fourth direction, the first direction is opposite to the second direction, and the third direction is opposite to the fourth direction.

[0016] In some embodiments, the first end of the transmission member is connected to the first valve core through a thread, and the second end of the transmission member is connected to the first end of the piston rod through a nut-screw pair.

[0017] In some embodiments, the hydraulic device also includes a control component and a drive component, the drive component includes a drive member, the drive member includes a drive unit, the drive unit is connected to the first valve core to drive the first valve core to move, the control component includes a controller, a first detection member and a second detection member, the controller is connected to the drive member, the first detection member is connected between the transmission member and the controller, the first detection member is used to detect the rotation angle of the transmission member, the second detection member is connected between the piston rod and the controller, and the second detection member is used to detect the moving distance of the piston rod.

[0018] In some embodiments, the drive assembly further comprises a coupling, a first end of the coupling is connected to the drive portion, and a second end of the coupling is connected to the first valve core via a spline.

[0019] The digital hydraulic cylinder of an embodiment of the present invention comprises a hydraulic device and a main valve. The hydraulic device is a hydraulic device with mechanical position pilot feedback according to any one of the above embodiments. The main valve comprises a second valve body and a second valve core. The second valve core is inserted into the second valve body, and the second valve core is movable along the axial direction of the second valve core. The valve cavity of the pilot valve is connected to the cavity of the main valve. The pilot valve is used to drive the second valve core to move. The main valve is connected to the hydraulic cylinder. The movement of the second valve core can drive the piston rod to move.

[0020] In some embodiments, the valve chamber of the pilot valve includes a first low-pressure chamber, a first chamber, a first high-pressure chamber, a second chamber, and a second low-pressure chamber that are connected in sequence; the valve chamber of the main valve includes a third chamber, a third low-pressure chamber, a second high-pressure chamber, a fourth low-pressure chamber, and a fourth chamber that are connected in sequence; the first chamber is connected to the third chamber, and the second chamber is connected to the fourth chamber; the main valve has a high-pressure oil port, a low-pressure oil port, a first inlet and outlet oil port, and a second inlet and outlet oil port; the first high-pressure chamber and the second high-pressure chamber are both connected to the high-pressure oil port; the first low-pressure chamber to the fourth low-pressure chamber are all connected to the low-pressure oil port; the high-pressure oil port is used to pass high-pressure oil; the low-pressure oil port is used to pass low-pressure oil; the first inlet and outlet oil port and the second inlet and outlet oil port are both connected to the hydraulic cylinder.

[0021] In some embodiments, the first valve core includes a first protrusion, a second protrusion and a third protrusion arranged in sequence, the first protrusion is used to connect and block the first low-pressure chamber and the first chamber, the second protrusion is used to connect and block the first high-pressure chamber with the first chamber and the second chamber, the third protrusion is used to connect and block the second chamber and the second low-pressure chamber, the second valve core includes a fourth protrusion, a fifth protrusion, a sixth protrusion and a seventh protrusion arranged in sequence, the fourth protrusion is used to connect and block the third chamber and the third low-pressure chamber, the fifth protrusion is used to connect and block the first inlet and outlet oil port with the third low-pressure chamber and the second high-pressure chamber, the sixth protrusion is used to connect and block the second inlet and outlet oil port with the second high-pressure chamber and the fourth low-pressure chamber, and the seventh protrusion is used to connect and block the fourth low-pressure chamber and the fourth chamber.

[0022] In some embodiments, the digital hydraulic cylinder has a first state and a second state. In the first state, the first high-pressure chamber is connected to the first chamber, the high-pressure oil flows into the third chamber, and drives the second valve core to move, so that the third low-pressure chamber is connected to the first inlet and outlet, and the first high-pressure chamber is connected to the second inlet and outlet.

[0023] In the second state, the first high-pressure chamber is connected to the second chamber, the high-pressure oil flows into the second chamber, and drives the second valve core to move, so that the fourth low-pressure chamber is connected to the second oil inlet and outlet, and the second high-pressure chamber is connected to the first oil inlet and outlet.

[0024] In some embodiments, the digital hydraulic cylinder of the embodiment of the present invention further includes a first elastic member and a second elastic member, the main valve includes a first mounting portion and a second mounting portion, the first mounting portion and the second mounting portion are relatively arranged in the axial direction of the second valve core, the first mounting portion is adjacent to the fourth protrusion and is located on the side of the fourth protrusion away from the second mounting portion, the second mounting portion is adjacent to the seventh protrusion and is located on the side of the seventh protrusion away from the first mounting portion, the first elastic member is arranged between the first mounting portion and the fourth protrusion, and the second elastic member is arranged between the second mounting portion and the seventh protrusion. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 The invention discloses a digital hydraulic cylinder.

[0026] Figure 2 It is a structural schematic diagram of a pilot valve and a main valve of a digital hydraulic cylinder according to an embodiment of the present invention.

[0027] Reference numerals:

[0028] Pilot valve 1; first valve body 11; first low-pressure chamber 111; first chamber 112; first high-pressure chamber 113; second chamber 114; second low-pressure chamber 115; first valve core 12; first protrusion 121; second protrusion 122; third protrusion 123;

[0029] Hydraulic cylinder 2; cylinder body 21; piston rod 22;

[0030] Transmission part 3;

[0031] Driving assembly 4; driving member 41; driving part 42; coupling 43;

[0032] Control component 5; controller 51; first detection member 52; second detection member 53;

[0033] Main valve 6; second valve body 61; third chamber 611; third low-pressure chamber 612; second high-pressure chamber 613; fourth low-pressure chamber 614; fourth chamber 615; high-pressure oil port 616; low-pressure oil port 617; first oil inlet and outlet 618; second oil inlet and outlet 619; second valve core 62; fourth protrusion 621; fifth protrusion 622; sixth protrusion 623; seventh protrusion 624; first mounting portion 63; second mounting portion 64;

[0034] a first elastic member 71 and a second elastic member 72 . DETAILED DESCRIPTION

[0035] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0036] The hydraulic device with mechanical position pilot feedback according to an embodiment of the present invention will be described below with reference to the accompanying drawings.

[0037] like Figure 1 and Figure 2 As shown, the hydraulic device with mechanical position pilot feedback according to the embodiment of the present invention comprises: a pilot valve 1 , a hydraulic cylinder 2 and a transmission member 3 .

[0038] The pilot valve 1 includes a first valve body 11 and a first valve core 12. The first valve core 12 is inserted into the first valve body 11 and is movable along the axis of the first valve core 12. The hydraulic cylinder 2 includes a cylinder body 21 and a piston rod 22. The first end of the piston rod 22 is located in the cylinder body 21 and is movable along the extension direction of the cylinder body 21. The second end of the piston rod 22 is located outside the cylinder body 21. The pilot valve 1 is connected to the hydraulic cylinder 2 to drive the piston rod 22 to move. The first end of the transmission member 3 is connected to the first end of the first valve core 12, and the second end of the transmission member 3 is connected to the first end of the piston rod 22. The pilot valve 1 is used to drive the piston rod 22 to move along the axial direction of the piston rod 22. The movement of the piston rod 22 is used to drive the first valve core 12 to move along the axial direction of the first valve core 12.

[0039] Specifically, Figure 1 and Figure 2 As shown, the first valve cavity and the first valve core 12 extend in the same direction (i.e., in the same direction as Figure 1 The first valve core 12 is movable in the left-right direction, and the extension direction of the cylinder body 21 of the hydraulic cylinder 2 is consistent with the extension direction of the piston rod 22 (i.e., consistent with the left-right direction of the cylinder body 21 of the hydraulic cylinder 2). Figure 1 The right end of the first valve core 12 is the first end of the first valve core 12, the left end of the transmission member 3 is the first end of the transmission member 3, the right end of the transmission member 3 is the second end of the transmission member 3, and the left end of the piston rod 22 is the first end of the piston rod 22.

[0040] It is understandable that if Figure 1 and Figure 2 As shown, the left and right ends of the first valve core 12 are both placed on the outside of the pilot valve 1, that is, the left end of the first valve core 12 can be connected to a driving device, such as a motor, to drive the first valve core 12 to move, and the right end of the first valve core 12 is connected to the left end of the transmission member 3.

[0041] In some embodiments, the first end of the transmission member 3 is connected to the first valve core 12 via a thread, and the second end of the transmission member 3 is connected to the first end of the piston rod 22 via a nut-screw pair.

[0042] It can be understood that the first valve core 12 can be driven by a driving device to rotate the first valve core 12. Since the right end of the first valve core 12 is threadedly connected to the first transmission member 3, the first valve core 12 also moves while rotating, thereby realizing the opening and closing of the pilot valve 1, so as to utilize hydraulic transmission to drive the piston rod 22 to move.

[0043] The piston rod 22 moves. Since the piston rod 22 is connected to the transmission member 3 through a nut-screw pair, the movement of the piston rod 22 can drive the transmission member 3 to rotate. The left end of the transmission member 3 is connected to the first valve core 12 through a thread. The rotation of the transmission member 3 can move the first valve core 12, thereby realizing the transmission of the displacement information of the piston rod 22 to the first valve core 12 by mechanical feedback, so as to improve the control accuracy of the hydraulic device.

[0044] That is to say, the hydraulic device with mechanical position pilot feedback in the embodiment of the present invention can use the transmission member 3 to mechanically connect the first valve core 12 and the piston rod 22, so that after the piston rod 22 is actuated, the displacement information of the piston rod 22 can be transmitted to the first valve core 12 by mechanical feedback, so as to improve the control accuracy of the hydraulic device.

[0045] In addition, the transmission member 3 can also provide mechanical feedback to the first valve core 12 after the piston rod 22 is actuated, so that the first valve core 12 can respond in time, thereby improving the response speed of the hydraulic device with mechanical position pilot feedback in the embodiment of the present invention.

[0046] In some embodiments, the first valve core 12 is movable between a first direction and a second direction to drive the piston rod 22 to move between a third direction and a fourth direction, wherein the first direction is opposite to the second direction and the third direction is opposite to the fourth direction.

[0047] It is understandable that if Figure 1 and Figure 2As shown, the first direction and the third direction are from the left to the right, and the second direction and the fourth direction are from the right to the left. It should be noted that, for example, the first valve core 12 moves in the first direction to open the pilot valve 1, and the hydraulic pressure difference is used to drive the piston rod 22 to move in the third direction. The movement of the piston rod 22 can drive the first valve core 12 to move in the second direction through the transmission member 3, thereby realizing mechanical feedback to the first valve core 12.

[0048] In some embodiments, the hydraulic device also includes a control component 5 and a drive component 4, the drive component 4 includes a drive member 41, the drive member 41 includes a drive unit 42, the drive unit 42 is connected to the first valve core 12 to drive the first valve core 12 to move, the control component 5 includes a controller 51, a first detection member 52 and a second detection member 53, the controller 51 is connected to the drive member 41, the first detection member 52 is connected between the transmission member 3 and the controller 51, the first detection member 52 is used to detect the rotation angle of the transmission member 3, the second detection member 53 is connected between the piston rod 22 and the controller 51, and the second detection member 53 is used to detect the moving distance of the piston rod 22.

[0049] Specifically, Figure 1 and Figure 2 As shown, the driving member 41 can be a motor, and the driving part 42 is the output shaft of the motor, so the driving part 42 can be connected to the first valve core 12 through the coupling 43. Therefore, after the driving member 41 is started, the function of driving the first valve core 12 to rotate can be realized, and through the connection between the first valve core 12 and the transmission member 3, the first valve core 12 can be moved in the left and right directions while rotating.

[0050] It is understandable that the first detection member 52 may be an encoder to detect the rotation angle of the transmission member 3, thereby transmitting the detected data to the controller 51 to control the output of the driving member 41. The second detection member 53 may be a displacement sensor to detect the displacement of the piston rod 22.

[0051] It should be noted that, when the driving member 41 is started and the piston rod 22 is driven to move through the pilot valve 1, etc., the displacement of the piston rod 22 can be detected in real time by the second detection member 53. At the same time, the movement of the piston rod 22 drives the transmission member 3 to rotate, and the movement of the piston rod 22 can be mechanically fed back to the first valve core 12. In addition, the first detection member 52 can also detect the rotation amount of the transmission member 3 in real time, so as to transmit the detected information to the controller 51.

[0052] That is, the driving member 41 can be started to move the first valve core 12 from the initial position in the first direction or the second direction, and the movement of the piston rod 22 can drive the first valve core 12 to move from the moved position to the initial position through the transmission member 3, so that the response speed of the pilot valve 1 in subsequent use is faster. In addition, the movement amount of the piston rod 22 and the rotation amount of the transmission member 3 are transmitted to the controller 51 through the second detection member 53 and the first detection member 52 respectively, so that the piston rod 22 can be corrected in time using the feedback information before it moves to the preset position, so that the movement accuracy of the piston rod 22 is more accurate.

[0053] In some embodiments, the driving assembly 4 further includes a coupling 43 , a first end of the coupling 43 is connected to the driving portion 42 , and a second end of the coupling 43 is connected to the first valve core 12 via a spline.

[0054] It can be understood that the second end of the coupling 43 is connected to the first valve core 12 via a spline, so that the first valve core 12 can rotate along the axis of the first valve core 12 and can also move in the left and right directions.

[0055] The digital hydraulic cylinder 2 of the embodiment of the present invention includes a hydraulic device and a main valve 6. The hydraulic device is a hydraulic device with mechanical position pilot feedback according to any one of the above embodiments. The main valve 6 includes a second valve body 61 and a second valve core 62. The second valve core 62 is inserted into the second valve body 61, and the second valve core 62 is movable along the axial direction of the second valve core 62. The valve cavity of the pilot valve 1 is connected to the cavity of the main valve 6. The pilot valve 1 is used to drive the second valve core 62 to move. The main valve 6 is connected to the hydraulic cylinder 2. The movement of the second valve core 62 can drive the piston rod 22 to move.

[0056] Specifically, Figure 1 and Figure 2 As shown, the second valve core 62 can move in the left-right direction, and the valve cavity of the pilot valve 1 is connected to the valve cavity of the main valve 6 so that external oil flows into the valve cavity of the main valve 6 through the valve cavity of the pilot valve 1.

[0057] It can be understood that the valve chamber of the pilot valve 1 can pass high-pressure liquid and low-pressure liquid. When the first valve core 12 moves, the high-pressure liquid and the low-pressure liquid flow into the valve chamber of the main valve 6 respectively, and form different pressures on the left and right sides of the second valve core 62, so that the pressure difference is used to drive the second valve core 62 to move, so as to realize the movement of the driving piston rod 22.

[0058] It should be noted that the pressure of the high-pressure liquid is greater than 16Mpa, and the pressure of the low-pressure liquid is less than 8Mpa.

[0059] In some embodiments, Figure 1 and Figure 2As shown, the valve chamber of the pilot valve 1 includes a first low-pressure chamber 111, a first chamber 112, a first high-pressure chamber 113, a second chamber 114 and a second low-pressure chamber 115 which are connected in sequence from left to right, and the valve chamber of the main valve 6 includes a third chamber 611, a third low-pressure chamber 612, a second high-pressure chamber 613, a fourth low-pressure chamber 614 and a fourth chamber 615 which are connected in sequence from left to right, the first chamber 112 is connected to the third chamber 611, and the second chamber 114 is connected to the fourth chamber 615.

[0060] like Figure 1 and Figure 2 As shown, the main valve 6 has a high-pressure oil port 616, a low-pressure oil port 617, a first oil inlet and outlet 618 and a second oil inlet and outlet 619, the first high-pressure chamber 113 and the second high-pressure chamber 613 are both connected to the high-pressure oil port 616, and the first low-pressure chamber 111 to the fourth low-pressure chamber 614 are all connected to the low-pressure oil port 617. The high-pressure oil port 616 is used to introduce high-pressure oil, and the low-pressure oil port 617 is used to introduce low-pressure oil. The first oil inlet and outlet 618 and the second oil inlet and outlet 619 are both connected to the hydraulic cylinder 2, so that when the first oil inlet and outlet 618 and the second oil inlet and outlet 619 flow out liquids of different pressures, the piston rod 22 can be driven to move in the left and right directions.

[0061] In some embodiments, Figure 1 and Figure 2 As shown, the first valve core 12 includes a first protrusion 121, a second protrusion 122 and a third protrusion 123 arranged in sequence, the first protrusion 121 is used to connect and block the first low-pressure chamber 111 and the first chamber 112, the second protrusion 122 is used to connect and block the first high-pressure chamber 113 and the first chamber 112 and the second chamber 114, the third protrusion 123 is used to connect and block the second chamber 114 and the second low-pressure chamber 115, and the second valve core 62 includes a fourth protrusion 621, a fifth protrusion 622 and a third protrusion 123 arranged in sequence. 622, the sixth protrusion 623 and the seventh protrusion 624, the fourth protrusion 621 is used to connect and block the third chamber 611 and the third low-pressure chamber 612, the fifth protrusion 622 is used to connect and block the first oil inlet and outlet 618 with the third low-pressure chamber 612 and the second high-pressure chamber 613, the sixth protrusion 623 is used to connect and block the second oil inlet and outlet 619 with the second high-pressure chamber 613 and the fourth low-pressure chamber 614, and the seventh protrusion 624 is used to connect and block the fourth low-pressure chamber 614 and the fourth chamber 615.

[0062] It can be understood that, for example, when the first valve core 12 moves from left to right, the first chamber 112 is connected to the first high-pressure chamber 113, and the second chamber 114 is connected to the second low-pressure chamber 115. The high-pressure liquid in the first high-pressure chamber 113 flows into the third chamber 611 through the first chamber 112, and the low-pressure liquid in the second low-pressure chamber 115 flows into the fourth chamber 615 through the second chamber 114. Due to the difference in liquid pressure, and the hydraulic pressure acting on the Disney protrusion acts on the pressure on the seventh protrusion, the second valve core 62 moves from left to right, and the third low pressure is connected to the first inlet and outlet oil port 618, and the second high-pressure chamber 613 is connected to the second inlet and outlet oil port 619. The low-pressure liquid in the third low-pressure chamber 612 can be discharged through the first inlet and outlet oil port 618, and the high-pressure liquid in the second high-pressure chamber 613 can be discharged through the second inlet and outlet oil port 619, thereby moving the piston rod 22 from right to left.

[0063] In some embodiments, the digital hydraulic cylinder 2 has a first state and a second state. In the first state, the first high-pressure chamber 113 is connected to the first chamber 112, and the high-pressure oil flows into the third chamber 611, and drives the second valve core 62 to move, so that the third low-pressure chamber 612 is connected to the first oil inlet and outlet 618, and the first high-pressure chamber 113 is connected to the second oil inlet and outlet 619. In the second state, the first high-pressure chamber 113 is connected to the second chamber 114, and the high-pressure oil flows into the second chamber 114, and drives the second valve core 62 to move, so that the fourth low-pressure chamber 614 is connected to the second oil inlet and outlet 619, and the second high-pressure chamber 613 is connected to the first oil inlet and outlet 618.

[0064] It can be understood that when the first valve core 12 moves from left to right, it is in the first state, and when the first valve core 12 moves from right to left, it is in the second state.

[0065] In some embodiments, the digital hydraulic cylinder 2 of the embodiment of the present invention also includes a first elastic member 71 and a second elastic member 72, the main valve 6 includes a first mounting portion 63 and a second mounting portion 64, the first mounting portion 63 and the second mounting portion 64 are arranged relatively to each other in the axial direction of the second valve core 62, the first mounting portion 63 is adjacent to the fourth protrusion 621 and is located on the side of the fourth protrusion 621 away from the second mounting portion 64, the second mounting portion 64 is adjacent to the seventh protrusion 624 and is located on the side of the seventh protrusion 624 away from the first mounting portion 63, the first elastic member 71 is arranged between the first mounting portion 63 and the fourth protrusion 621, and the second elastic member 72 is arranged between the second mounting portion 64 and the seventh protrusion 624.

[0066] Specifically, Figure 1 and Figure 2As shown, the first mounting portion 63 is located on the left side of the second valve cavity, and the second mounting portion 64 is displaced to the right side of the second valve cavity. Optionally, the first elastic member 71 and the second elastic member 72 are both springs. Of course, the first elastic member 71 and the second elastic member 72 can also be elastic components such as rubber.

[0067] It can be understood that in the initial state of the digital hydraulic cylinder 2 of the embodiment of the present invention, both the first elastic member 71 and the second elastic member 72 are not subjected to force. When the second valve core 62 moves under the action of the hydraulic pressure difference, so that one of the first elastic member 71 and the second elastic member 72 is subjected to tension, and the other is subjected to pressure, then after the effect of the hydraulic pressure difference on the second valve core 62 is cancelled, under the action of the elastic force of the first elastic member 71 and the second elastic member 72, it is conducive to the second valve core 62 to quickly return to the initial state (i.e., the balanced state).

[0068] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0069] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0070] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0071] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0072] In the present invention, the terms "one embodiment", "some embodiments", "examples", "specific examples", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0073] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A digital hydraulic cylinder, characterized in that: The invention comprises a hydraulic device and a main valve with mechanical position pilot feedback, wherein the hydraulic device comprises: A pilot valve, the pilot valve comprising a first valve body and a first valve core, the first valve core is inserted into the first valve body, and the first valve core is movable along the axis of the first valve core; A hydraulic cylinder, the hydraulic cylinder comprising a cylinder body and a piston rod, the first end of the piston rod is located in the cylinder body and is movable along the extension direction of the cylinder body, the second end of the piston rod is located outside the cylinder body, and the pilot valve is connected to the hydraulic cylinder to drive the piston rod to move; a transmission member, wherein a first end of the transmission member is connected to a first end of the first valve core, a second end of the transmission member is connected to a first end of the piston rod, the pilot valve is used to drive the piston rod to move along the axial direction of the piston rod, and the movement of the piston rod is used to drive the first valve core to move along the axial direction of the first valve core; A control assembly and a drive assembly, wherein the drive assembly includes a drive member, the drive member includes a drive part, the drive part is connected to the first valve core to drive the first valve core to move, the control assembly includes a controller, a first detection member and a second detection member, the controller is connected to the drive member, the first detection member is connected between the transmission member and the controller, the first detection member is used to detect the rotation angle of the transmission member, the second detection member is connected between the piston rod and the controller, and the second detection member is used to detect the movement distance of the piston rod; The main valve comprises a second valve body and a second valve core, the second valve core is inserted into the second valve body, and the second valve core is movable along the axial direction of the second valve core, the valve cavity of the pilot valve is connected to the cavity of the main valve, the pilot valve is used to drive the second valve core to move, the main valve is connected to the hydraulic cylinder, and the movement of the second valve core can drive the piston rod to move; The valve chamber of the pilot valve includes a first low-pressure chamber, a first chamber, a first high-pressure chamber, a second chamber, and a second low-pressure chamber that are connected in sequence. The valve chamber of the main valve includes a third chamber, a third low-pressure chamber, a second high-pressure chamber, a fourth low-pressure chamber, and a fourth chamber that are connected in sequence. The first chamber is connected to the third chamber, and the second chamber is connected to the fourth chamber. The main valve has a high-pressure oil port, a low-pressure oil port, a first oil inlet and outlet, and a second oil inlet and outlet. The first high-pressure chamber and the second high-pressure chamber are both connected to the high-pressure oil port, and the first low-pressure chamber to the fourth low-pressure chamber are all connected to the low-pressure oil port. The high-pressure oil port is used to introduce high-pressure oil, and the low-pressure oil port is used to introduce low-pressure oil. The first oil inlet and outlet and the second oil inlet and outlet are both connected to the hydraulic cylinder.

2. The digital hydraulic cylinder according to claim 1, characterized in that: The first valve core is movable between a first direction and a second direction to drive the piston rod to move between a third direction and a fourth direction, the first direction is opposite to the second direction, and the third direction is opposite to the fourth direction.

3. The digital hydraulic cylinder according to claim 2, characterized in that: The first end of the transmission member is connected to the first valve core through a thread, and the second end of the transmission member is connected to the first end of the piston rod through a nut and screw pair.

4. The digital hydraulic cylinder according to claim 3, characterized in that: The driving assembly further comprises a coupling, a first end of the coupling is connected to the driving part, and a second end of the coupling is connected to the first valve core via a spline.

5. The digital hydraulic cylinder according to claim 1, characterized in that: The first valve core comprises a first protrusion, a second protrusion and a third protrusion arranged in sequence, the first protrusion is used to connect and block the first low-pressure chamber and the first chamber, the second protrusion is used to connect and block the first high-pressure chamber, the first chamber and the second chamber, and the third protrusion is used to connect and block the second chamber and the second low-pressure chamber. The second valve core includes a fourth protrusion, a fifth protrusion, a sixth protrusion and a seventh protrusion arranged in sequence, the fourth protrusion is used to connect and block the third chamber and the third low-pressure chamber, the fifth protrusion is used to connect and block the first oil inlet and outlet port and the third low-pressure chamber and the second high-pressure chamber, the sixth protrusion is used to connect and block the second oil inlet and outlet port and the second high-pressure chamber and the fourth low-pressure chamber, and the seventh protrusion is used to connect and block the fourth low-pressure chamber and the fourth chamber.

6. The digital hydraulic cylinder according to claim 5, characterized in that: The digital hydraulic cylinder has a first state and a second state. In the first state, the first high-pressure chamber is connected to the first chamber, the high-pressure oil flows into the third chamber, and drives the second valve core to move, so that the third low-pressure chamber is connected to the first oil inlet and outlet, and the second high-pressure chamber is connected to the second oil inlet and outlet; In the second state, the first high-pressure chamber is connected to the second chamber, the high-pressure oil flows into the second chamber, and drives the second valve core to move, so that the fourth low-pressure chamber is connected to the second oil inlet and outlet, and the second high-pressure chamber is connected to the first oil inlet and outlet.

7. The digital hydraulic cylinder according to claim 5, characterized in that: It also includes a first elastic member and a second elastic member, the main valve includes a first mounting portion and a second mounting portion, the first mounting portion and the second mounting portion are arranged relatively to each other in the axial direction of the second valve core, the first mounting portion is adjacent to the fourth protrusion and is located on a side of the fourth protrusion away from the second mounting portion, the second mounting portion is adjacent to the seventh protrusion and is located on a side of the seventh protrusion away from the first mounting portion, the first elastic member is arranged between the first mounting portion and the fourth protrusion, and the second elastic member is arranged between the second mounting portion and the seventh protrusion.

Images