Digital hydraulic cylinder and excavator

Abstract

This invention discloses a digital hydraulic cylinder and an excavator, relating to the field of hydraulic drive technology. It includes a hydraulic cylinder body and a control assembly mounted on the hydraulic cylinder body. A first ball screw has one end fixedly connected to the output end of a drive motor and the other end drivingly connected to a first screw nut, which is connected to the first end of a valve core. A second ball screw has one end connected to the second end of the valve core, drivingly connected to a second screw nut, and rotatably connected to a valve body. The second screw nut has helical teeth circumferentially arranged, and the hydraulic cylinder body also has a helical rack that slides along the axis of the valve core. The helical rack meshes with the helical teeth and is fixedly connected to a piston rod via a connecting rod. This design enables precise control of the hydraulic cylinder without altering its internal structure, simplifying the installation structure and facilitating future maintenance.

Description

Technical Field

[0001] The present invention relates to the technical field of hydraulic drive, and in particular to a digital hydraulic cylinder and an excavator. Background Art

[0002] The hydraulic cylinder is an energy conversion device that converts hydraulic energy into mechanical energy. It is a commonly used actuator in hydraulic systems. In traditional hydraulic control systems, the force, speed and position output by the hydraulic cylinder are controlled by external hydraulic components in the entire system, so precise adjustment and control cannot be achieved.

[0003] As the needs of society and industry put forward higher requirements for the control accuracy of hydraulic components, traditional hydraulic control systems cannot meet today's higher requirements. Therefore, in order to achieve the demand for precise control, digital hydraulic cylinders came into being. A ball screw is installed inside the digital hydraulic cylinder and connected to the valve core to accurately control the position of the hydraulic cylinder piston. The movement speed of the piston is adjusted by changing the pulse frequency received by the stepper motor. The piston position is determined by controlling the number of electrical pulses received by the stepper motor.

[0004] However, the existing digital hydraulic cylinder sets the ball screw, valve core, etc. inside the hydraulic cylinder, which requires reprocessing and modification of the internal structure of the hydraulic cylinder, causing difficulties in assembly and being unfavorable for subsequent maintenance. Summary of the invention

[0005] The purpose of the present invention is to provide a digital hydraulic cylinder and an excavator, which can realize accurate control of the hydraulic cylinder without changing the internal structure of the hydraulic cylinder, thereby simplifying the installation structure and facilitating subsequent maintenance.

[0006] The embodiment of the present invention is achieved as follows:

[0007] In one aspect of an embodiment of the present invention, a digital hydraulic cylinder is provided, comprising a hydraulic cylinder body and a regulating component arranged on the hydraulic cylinder body; the hydraulic cylinder body comprises a cylinder body and a piston rod arranged in the cylinder body, the piston rod divides the cylinder body into a rod chamber and a rodless chamber; the regulating component comprises a driving motor capable of receiving a pulse signal, a sliding valve, a first ball screw, a first screw nut, a second ball screw, and a second screw nut, the sliding valve comprises a valve body arranged on the hydraulic cylinder body and a valve core arranged in the valve body, the valve core can move axially along the valve body; one end of the first ball screw is fixedly connected to the output end of the driving motor, and the other end is connected to the first ball screw A lead screw nut is connected in a transmission manner, the first lead screw nut is connected to the first end of the valve core; one end of the second ball screw is connected to the second end of the valve core, the second ball screw is connected in a transmission manner to the second lead screw nut, and the second lead screw nut is rotationally connected to the valve body; a plurality of oil through holes are provided on the valve body, wherein the first oil through hole among the plurality of oil through holes is connected to the rod chamber, and the second oil through hole among the plurality of oil through holes is connected to the rodless chamber; the second lead screw nut is circumferentially provided with helical teeth, and the hydraulic cylinder body is also provided with a helical rack sliding along the direction of the axis of the valve core, the helical racks are meshed with the helical teeth for transmission, and the helical racks are fixedly connected to the piston rod through a connecting rod.

[0008] Optionally, the regulating component further includes a first coupling and a second coupling, the first ball screw nut is connected to the first end of the valve core through the first coupling, and the second ball screw is connected to the second end of the valve core through the second coupling.

[0009] Optionally, the first coupling and the second coupling are both universal couplings.

[0010] Optionally, a limiting groove is provided on the inner wall of the valve body, and a limiting protrusion is correspondingly provided on the valve core to cooperate with the limiting groove, or a protrusion is provided on the inner wall of the valve body, and a groove cooperating with the protrusion is correspondingly provided on the valve core, so that the valve core can only move along the axial direction of the valve core.

[0011] Optionally, a slide groove is provided on the hydraulic cylinder body along the direction of the valve core axis, and a slide rail is correspondingly provided on the bevel rack, or a guide slide rail is provided on the hydraulic cylinder body along the direction of the valve core axis, and a guide slide groove is correspondingly provided on the bevel rack, so that the bevel rack slides along the direction of the axis of the valve core.

[0012] Optionally, the cross section of the slide groove or the guide slide groove is trapezoidal or rectangular.

[0013] Optionally, the regulating assembly further includes a bearing, which is disposed between the second lead screw nut and the valve body so as to enable the second lead screw nut to be rotationally connected to the valve body.

[0014] Optionally, a connecting seat is provided at one end of the first ball screw away from the first screw nut, and the first ball screw is fixedly connected to the output end of the driving motor through the connecting seat.

[0015] Optionally, the regulating component also includes a protective shell, which is arranged on a side of the valve body close to the drive motor, and the drive motor, the first ball screw, and the first screw nut are all located in the protective shell.

[0016] Another aspect of an embodiment of the present invention provides an excavator, comprising a working arm and a bucket connected to each other, and a digital hydraulic cylinder as described above, wherein the digital hydraulic cylinder is arranged on the working arm and is drivingly connected to the bucket.

[0017] The beneficial effects of the embodiments of the present invention include:

[0018] The digital hydraulic cylinder and excavator provided by the embodiment of the present invention facilitate the integrated control of the hydraulic cylinder through the hydraulic cylinder body and the through-hole assembly set on the hydraulic cylinder body, and there is no need to change the internal structure of the hydraulic cylinder. By fixing one end of the first ball screw with the output end of the driving motor and the other end with the first lead screw nut, when the driving motor moves according to the pulse signal, the output end of the driving motor drives the first ball screw to move synchronously, and the rotation of the first ball screw drives the first lead screw nut to move along the direction of the axis of the first ball screw. Since the first lead screw nut is connected to the first end of the valve core, the first lead screw nut drives the axial movement of the valve core when it moves. The axial movement of the valve core makes the first oil path through hole on the valve body communicate with the rod cavity, and the second oil path through hole communicates with the rodless cavity, thereby forming a hydraulic path to drive the piston rod to move. When the piston rod moves, the helical rack fixedly connected to the piston rod through the connecting rod moves synchronously with the piston rod. Due to the helical teeth meshing transmission of the helical rack and the circumferentially arranged helical teeth of the second lead screw nut, the second lead screw nut will be driven to rotate when the piston rod moves. The second ball screw is connected to the second screw nut in a transmission manner. When the second screw nut rotates, the second ball screw moves axially, thereby driving the valve core to move axially, and the direction of movement is opposite to the direction of movement of the valve core driven by the drive motor to form a mechanical negative feedback. In this way, the hydraulic path can be closed, so that the piston rod stops moving. The above movement is a microstep of the digital hydraulic cylinder movement. If the piston rod needs to move continuously, it is necessary to send a pulse signal to the drive motor at a specific frequency. Whenever the drive motor receives a pulse signal, it controls the movement of the valve core to open a small displacement of the oil circuit through hole to form a hydraulic path. The high-pressure oil pushes the piston rod to move a corresponding distance while closing the oil circuit through hole to stop the piston rod. When working, the digital hydraulic cylinder continues this action to complete the required amount of propulsion. Through the above structure, it is possible to achieve precise control of the hydraulic cylinder without changing the internal structure of the hydraulic cylinder, thereby simplifying the installation structure and facilitating later maintenance. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments are briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without creative work.

[0020] Figure 1 One of the structural schematic diagrams of the digital hydraulic cylinder provided in an embodiment of the present invention;

[0021] Figure 2 A schematic diagram of the structure of a control component provided by an embodiment of the present invention;

[0022] Figure 3 A schematic structural diagram of a double cross-type universal coupling provided in an embodiment of the present invention;

[0023] Figure 4 One of the cross-sectional schematic diagrams of the valve body and the valve core limit position provided in the embodiment of the present invention;

[0024] Figure 5 The second cross-sectional schematic diagram of the valve body and the valve core limit position provided in the embodiment of the present invention;

[0025] Figure 6 The second structural schematic diagram of the digital hydraulic cylinder provided in the embodiment of the present invention.

[0026] Icon: 100-digital hydraulic cylinder; 110-hydraulic cylinder body; 111-cylinder body; 1112-rod chamber; 1114-rodless chamber; 112-piston rod; 114-slide groove; 120-regulating component; 121-driving motor; 122-slide valve; 1222-valve body; 1222a-limiting groove; 1222b-protrusion; 1224-valve core; 1224a-limiting protrusion; 1224b-groove; 1226-first oil circuit through hole; 122 8-second oil passage hole; 123-first ball screw; 1232-connecting seat; 124-first screw nut; 125-second ball screw; 126-second screw nut; 1262-bearing; 127-bevel rack; 1272-slide rail; 128-first coupling; 129-second coupling; 130-connecting rod; 140-universal coupling; 142-first connecting part; 144-second connecting part; 146-rotating part; 150-protective shell. DETAILED DESCRIPTION

[0027] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Generally, the components of the embodiments of the present invention described and shown in the drawings here can be arranged and designed in various different configurations.

[0028] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the invention claimed for protection, but merely represents selected embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0029] It should be noted that similar reference numerals and letters represent similar items in the following drawings, so once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. In addition, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0030] In the description of the present invention, it is also necessary to explain that, unless otherwise clearly specified and limited, the terms "disposed" and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be an indirect connection through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0031] Please refer to Figure 1The present embodiment provides a digital hydraulic cylinder 100, comprising a hydraulic cylinder body 110 and a regulating component 120 arranged on the hydraulic cylinder body 110; the hydraulic cylinder body 110 comprises a cylinder body 111 and a piston rod 112 arranged in the cylinder body 111, the piston rod 112 divides the cylinder body 111 into a rod chamber 1112 and a rodless chamber 1114; the regulating component 120 comprises a driving motor 121 capable of receiving a pulse signal, a sliding valve 122, a first ball screw 123, a first screw nut 124, a second ball screw 125, and a second screw nut 126, the sliding valve 122 comprises a valve body 1222 arranged on the hydraulic cylinder body 110 and a valve core 1224 arranged in the valve body 1222, the valve core 1224 being capable of moving axially along the valve body 1222; one end of the first ball screw 123 is fixedly connected to the output end of the driving motor 121, The other end is connected to the first screw nut 124 for transmission, and the first screw nut 124 is connected to the first end of the valve core 1224; one end of the second ball screw 125 is connected to the second end of the valve core 1224, the second ball screw 125 is connected to the second screw nut 126 for transmission, and the second screw nut 126 is rotatably connected to the valve body 1222; the valve body 1222 is provided with a plurality of oil through holes, wherein the first oil through hole 1226 among the plurality of oil through holes is connected to the rod chamber 1112, and the second oil through hole 1228 among the plurality of oil through holes is connected to the rodless chamber 1114; the second screw nut 126 is circumferentially provided with helical teeth, and the hydraulic cylinder body 110 is also provided with a helical rack 127 which slides along the direction of the axis of the valve core 1224, the helical rack 127 is meshed with the helical teeth for transmission, and the helical rack 127 is fixedly connected to the piston rod 112 through a connecting rod 130.

[0032] It should be noted that, first, the piston rod 112 includes a push rod and a piston connected to one end of the push rod, and the piston divides the hydraulic cylinder body 110 into a rod chamber 1112 and a rodless chamber 1114 that are not connected to each other, that is, the piston rod 112 divides the cylinder body 111 into a rod chamber 1112 and a rodless chamber 1114. Among them, the rod chamber 1112 refers to the cavity space with the push rod, and the rodless chamber 1114 refers to the cavity space without the push rod.

[0033] Second, the drive motor 121 that can receive the pulse signal includes a stepper motor and a servo motor. The drive motor 121 used in this embodiment can be a stepper motor or a servo motor, as long as it can ensure the normal operation of the control component 120. In addition, the pulse signal includes a positive pulse and a negative pulse to control the forward rotation and flipping of the drive motor 121, thereby controlling the extension and retraction of the piston rod 112.

[0034] Third, the slide valve 122 of this embodiment adopts a reciprocating structure, the valve core 1224 can move axially along the valve body 1222, the valve core 1224 is provided with a shoulder, and the valve body 1222 is provided with an annular groove. The slide valve 122 controls the size and position of the throttle by controlling the sliding of the valve core 1224 in the valve body 1222, thereby controlling the flow rate flowing through the oil passage hole. For examples, please refer to Figure 1 and Figure 2 In the initial state, the valve core 1224 is in the middle position, at which time, the hydraulic oil inlet P is disconnected from the first oil circuit through hole 1226 and the second oil circuit through hole 1228. When the drive motor 121 receives a positive pulse, the drive motor 121 moves, thereby driving the valve core 1224 to move rightward through the first ball screw 123 and the first screw nut 124, so that the hydraulic oil inlet P on the valve body 1222 is connected with the second oil circuit through hole 1228 and the oil port B at the rodless chamber 1114 in sequence, and the oil return port T on the valve body 1222 is connected with the first oil circuit through hole 1226 and the oil port A at the rod chamber 1112 in sequence. When the piston rod 112 is extended, the valve core 1224 is reset to the initial state under the action of mechanical negative feedback. Similarly, when the drive motor 121 receives a negative pulse, the drive motor 121 moves, thereby driving the valve core 1224 to move leftward through the first ball screw 123 and the first screw nut 124, so that the hydraulic oil inlet P on the valve body 1222 is connected with the first oil circuit through hole 1226 and the oil port A at the rod chamber 1112 in sequence, and the oil return port T on the valve body 1222 is connected with the second oil circuit through hole 1228 and the oil port B at the rodless chamber 1114 in sequence. When the piston rod 112 retracts, the valve core 1224 is reset to the initial state under the action of mechanical negative feedback. In addition, depending on the different rotation directions of the first ball screw 123 and the first screw nut 124, when the drive motor 121 receives a positive pulse, the piston rod 112 retracts; when the drive motor 121 receives a negative pulse, the piston rod 112 extends.

[0035] Fourth, when the piston rod 112 is extended, the connecting rod 130 drives the bevel rack 127 to move synchronously, and the bevel rack 127 and the bevel teeth arranged circumferentially on the second screw nut 126 are meshed and transmitted. Since the second screw nut 126 is rotationally connected to the valve body 1222, and the second ball screw 125 is transmission-connected to the second screw nut 126, one end of the second ball screw 125 is connected to the second end of the valve core 1224, so that the piston rod 112 drives the bevel rack 127 to move, the bevel rack 127 drives the second screw nut 126 to move, the second screw nut 126 drives the second ball screw 125 to move, and the second ball screw 125 drives the valve core 1224 to return to the initial state, so as to form mechanical negative feedback. Similarly, when the piston rod 112 is retracted, the valve core 1224 also needs to be restored to the initial state according to this connection relationship. In addition, when the transmission is specifically connected, the inclination direction of the helical teeth circumferentially arranged on the helical rack 127 and the second screw nut 126, as well as the rotation direction between the second ball screw 125 and the second screw nut 126 are all related. The present application does not impose specific restrictions on this, as long as the valve core 1224 can be reset to its initial state when the piston rod 112 is extended or retracted.

[0036] Fifth, the present embodiment does not impose any specific restrictions on the position at which the connecting rod 130 is fixedly connected to the piston rod 112. For example, the connecting rod 130 can be disposed at the end of the piston rod 112, or at other suitable positions, as long as it does not affect the connection between the piston rod 112 and other transmission components and the retraction of the piston rod 112.

[0037] The digital hydraulic cylinder 100 provided in the embodiment of the present invention facilitates integrated control of the hydraulic cylinder through the hydraulic cylinder body 110 and the through-hole assembly provided on the hydraulic cylinder body 110, and there is no need to change the internal structure of the hydraulic cylinder. By fixing one end of the first ball screw 123 to the output end of the drive motor 121 and the other end to the first screw nut 124 in transmission connection, when the drive motor 121 moves according to the pulse signal, the output end of the drive motor 121 drives the first ball screw 123 to move synchronously, and the rotation of the first ball screw 123 drives the first screw nut 124 to move along the direction of the axis of the first ball screw 123. Since the first lead screw nut 124 is connected to the first end of the valve core 1224, the first lead screw nut 124 drives the valve core 1224 to move axially when it moves. The axial movement of the valve core 1224 makes the first oil path through hole 1226 on the valve body 1222 communicate with the rod chamber 1112, and the second oil path through hole 1228 communicates with the rodless chamber 1114, thereby forming a hydraulic path to drive the piston rod 112 to move. When the piston rod 112 moves, the bevel rack 127 fixedly connected to the piston rod 112 through the connecting rod 130 moves synchronously with the piston rod 112. Since the bevel rack 127 and the bevel teeth arranged circumferentially on the second lead screw nut 126 are meshed and driven, the second lead screw nut 126 will be driven to rotate when the piston rod 112 moves. The second ball screw 125 is connected to the second screw nut 126 in a transmission manner. When the second screw nut 126 rotates, the second ball screw 125 moves axially, thereby driving the valve core 1224 to move axially, and the direction of movement is opposite to the direction of movement of the valve core 1224 driven by the drive motor 121, so as to form a mechanical negative feedback. In this way, the hydraulic path can be closed, so that the piston rod 112 stops moving. The above movement is a microstep of the movement of the digital hydraulic cylinder 100. If the piston rod 112 needs to move continuously, a pulse signal needs to be sent to the drive motor 121 at a specific frequency. Whenever the drive motor 121 receives the pulse signal, the valve core 1224 is controlled to move, so that the oil circuit through hole opens a small displacement to form a hydraulic path. The high-pressure oil pushes the piston rod 112 to move a corresponding distance while closing the oil circuit through hole, so that the piston rod 112 stops. When working, the digital hydraulic cylinder 100 continues this action to complete the required amount of propulsion. Through the above structure, the hydraulic cylinder can be accurately controlled without changing the internal structure of the hydraulic cylinder, thereby simplifying the installation structure and facilitating later maintenance.

[0038] like Figure 2 As shown, the regulating assembly 120 also includes a first coupling 128 and a second coupling 129 , the first screw nut 124 is connected to the first end of the valve core 1224 through the first coupling 128 , and the second ball screw 125 is connected to the second end of the valve core 1224 through the second coupling 129 .

[0039] Specifically, the first lead screw nut 124 includes a connection cavity connected to the first ball screw 123, and a connection end connected to the first coupling 128. When the first lead screw nut 124 and the first ball screw 123 rotate relative to each other, there is a movable margin between the first lead screw nut 124 and the first ball screw 123. Since the relative movement distance between the first lead screw nut 124 and the first ball screw 123 is small each time, this structure does not affect the normal transmission. Since the first end of the first lead screw nut 124 and the valve core 1224 is a connection between shafts, the first coupling 128 can make the first lead screw nut 124 and the first end of the valve core 1224 more convenient and reliable. Similarly, since the second end of the second ball screw 125 and the valve core 1224 is a connection between shafts, the second coupling 129 can make the second ball screw 125 and the second end of the valve core 1224 more convenient and reliable.

[0040] In order to avoid the situation where the valve core 1224 rotates during axial movement when other couplings are used, thereby affecting the sealing between the valve body 1222 and the valve core 1224, in a preferred embodiment of the present embodiment, the first coupling 128 and the second coupling 129 are both universal couplings 140. Figure 3 As shown, the universal coupling 140 of this embodiment includes a first connection part 142, a second connection part 144 and a rotating part 146, wherein one end of the first connection part 142 and one end of the second connection part 144 are rotatably connected through the rotating part 146. In this embodiment, the universal coupling 140 specifically refers to a coupling in which the first connection part 142 and the second connection part 144 can be rotatably connected, and the first connection part 142 and the second connection part 144 can be rotatably connected by the form of shaft hole matching, or can be realized by other forms such as bearings 1262, and can be limited by a retaining spring. When assembled and used, the other end of the first connection part 142 and the other end of the second connection part 144 are respectively connected to the two parts that need to be connected, such as connecting the first screw nut 124 with the first end of the valve core 1224, or connecting the second ball screw 125 with the second end of the valve core 1224. In this way, when the first ball screw 123 or the second ball screw 125 rotates, the valve core 1224 is prevented from synchronously rotating with the first ball screw 123 or the second ball screw 125 , which is beneficial to improving the sealing performance of the sliding valve 122 .

[0041] like Figure 4 As shown, the inner wall of the valve body 1222 is provided with a limiting groove 1222a, and the valve core 1224 is correspondingly provided with a limiting protrusion 1224a that cooperates with the limiting groove 1222a. Please refer to Figure 5In this embodiment, the inner wall of the valve body 1222 may be provided with a protrusion 1222b, and the valve core 1224 may be provided with a corresponding groove 1224b that cooperates with the protrusion 1222b, so that the valve core 1224 can only move along the axial direction of the valve core 1224.

[0042] It should be noted that the extending direction of the limiting groove 1222a or the protrusion 1222b needs to be consistent with the axial direction of the valve core 1224 to ensure that the valve core 1224 does not rotate when moving along the axial direction of the valve core 1224. When the valve core 1224 moves axially, the rotating part 146 rotates to ensure normal transmission.

[0043] like Figure 1 and Figure 6 As shown, a slide groove 114 is provided on the hydraulic cylinder body 110 along the direction of the axis of the valve core 1224, and a slide rail 1272 is correspondingly provided on the bevel rack 127, or a guide slide rail 1272 is provided on the hydraulic cylinder body 110 along the direction of the axis of the valve core 1224, and a guide slide groove 114 is correspondingly provided on the bevel rack 127, so that the bevel rack 127 slides along the direction of the axis of the valve core 1224.

[0044] In this way, when the piston rod 112 is extended or retracted, the bevel rack 127 can be ensured to slide along a specific track to prevent the bevel rack 127 from being skewed, so as not to affect the normal meshing between the bevel rack 127 and the bevel teeth arranged circumferentially on the second lead screw nut 126. Through the above structure, it can be ensured that the linear motion of the bevel rack 127 is converted into the rotational motion of the second lead screw nut 126, thereby driving the axial motion of the second ball screw 125. In this embodiment, the bevel rack 127 specifically refers to a rack that can normally mesh with the bevel teeth arranged circumferentially on the second lead screw nut 126.

[0045] In an optional solution of this embodiment, the cross section of the slide groove 114 or the guide slide groove 114 is a trapezoid or a rectangle. Specifically, when the cross section of the slide groove 114 is a trapezoid, the corresponding slide rail 1272 on the bevel rack 127 is also a trapezoid, so that the slide groove 114 forms a dovetail groove structure, which can further limit the bevel rack 127. When the cross section of the guide slide groove 114 is a rectangle, the corresponding guide slide rail 1272 on the bevel rack 127 is also a rectangle. At this time, the bevel rack 127 can be limited by the connecting rod 130, or by the cavity, so as to ensure the stability of the bevel rack 127 when it moves.

[0046] like Figure 2As shown, the regulating assembly 120 further includes a bearing 1262, which is disposed between the second lead screw nut 126 and the valve body 1222 so as to enable the second lead screw nut 126 to be rotatably connected to the valve body 1222. Specifically, the outer ring of the bearing 1262 is fixedly connected to the inner wall of the valve body 1222, and the inner ring of the bearing 1262 is fixedly connected to the second lead screw nut 126. At the same time, a retaining spring can also be used to axially limit the bearing 1262 to ensure the stability of the connection, so that the second lead screw nut 126 rotates more stably and reliably.

[0047] like Figure 2 As shown, a connection seat 1232 is provided at one end of the first ball screw 123 away from the first screw nut 124, and the first ball screw 123 is fixedly connected to the output end of the drive motor 121 through the connection seat 1232. Specifically, a fixing hole may be provided on the side of the connection seat 1232 to facilitate connection and positioning from the side by bolts. The connection seat 1232 facilitates the connection and fixation of the first ball screw 123 and the output end of the drive motor 121, which is conducive to simplifying the installation form.

[0048] like Figure 2 As shown, the regulating assembly 120 further includes a protective shell 150, which is disposed on a side of the valve body 1222 close to the drive motor 121, and the drive motor 121, the first ball screw 123, and the first screw nut 124 are all located in the protective shell 150. In this way, the drive motor 121 and the first ball screw 123, the first screw nut 124 and other transmission parts can be stably connected during use, ensuring stability during operation and reducing the influence of external interference.

[0049] The embodiment of the present invention further provides an excavator, comprising a working arm and a bucket connected to each other, and a digital hydraulic cylinder 100 as described above, wherein the digital hydraulic cylinder 100 is arranged on the working arm and is drivingly connected to the bucket. The excavator includes the same structure and beneficial effects as the digital hydraulic cylinder 100 in the aforementioned embodiment. The structure and beneficial effects of the digital hydraulic cylinder 100 have been described in detail in the aforementioned embodiment, and will not be repeated here.

[0050] The above are only preferred embodiments of the present invention and are not intended to limit the present invention. For those skilled in the art, the present invention may have various modifications and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.

Claims

1. A digital hydraulic cylinder, characterized in that: It includes a hydraulic cylinder body and a regulating component arranged on the hydraulic cylinder body; the hydraulic cylinder body includes a cylinder body and a piston rod arranged in the cylinder body, and the piston rod divides the cylinder body into a rod chamber and a rodless chamber; the regulating component includes a driving motor capable of receiving a pulse signal, a sliding valve, a first ball screw, a first screw nut, a second ball screw, and a second screw nut, the sliding valve includes a valve body arranged on the hydraulic cylinder body and a valve core arranged in the valve body, and the valve core can move axially along the valve body; one end of the first ball screw is fixedly connected to the output end of the driving motor, and the other end is drivingly connected to the first screw nut, and the first screw The nut is connected to the first end of the valve core; one end of the second ball screw is connected to the second end of the valve core, the second ball screw is connected to the second screw nut in transmission connection, and the second screw nut is rotationally connected to the valve body; a plurality of oil through holes are provided on the valve body, wherein a first oil through hole among the plurality of oil through holes is connected to the rod chamber, and a second oil through hole among the plurality of oil through holes is connected to the rodless chamber; the second screw nut is circumferentially provided with helical teeth, and the hydraulic cylinder body is also provided with a helical rack sliding along the direction of the axis of the valve core, the helical rack is meshed with the helical teeth for transmission, and the helical rack is fixedly connected to the piston rod through a connecting rod.

2. The digital hydraulic cylinder according to claim 1, characterized in that: The regulating component also includes a first coupling and a second coupling. The first ball screw nut is connected to the first end of the valve core through the first coupling, and the second ball screw is connected to the second end of the valve core through the second coupling.

3. The digital hydraulic cylinder according to claim 2, characterized in that: The first coupling and the second coupling are both universal couplings.

4. The digital hydraulic cylinder according to claim 3, characterized in that: A limiting groove is provided on the inner wall of the valve body, and a limiting protrusion matching with the limiting groove is correspondingly provided on the valve core, or a protrusion is provided on the inner wall of the valve body, and a groove matching with the protrusion is correspondingly provided on the valve core, so that the valve core can only move along the axial direction of the valve core.

5. The digital hydraulic cylinder according to claim 1, characterized in that: A slide groove is provided on the hydraulic cylinder body along the direction of the valve core axis, and a slide rail is correspondingly provided on the bevel rack, or a guide slide rail is provided on the hydraulic cylinder body along the direction of the valve core axis, and a guide slide groove is correspondingly provided on the bevel rack, so that the bevel rack slides along the direction of the axis where the valve core is located.

6. The digital hydraulic cylinder according to claim 5, characterized in that: The cross section of the slide groove or the guide slide groove is trapezoidal or rectangular.

7. The digital hydraulic cylinder according to claim 1, characterized in that: The regulating component also includes a bearing, which is arranged between the second lead screw nut and the valve body so that the second lead screw nut is rotatably connected to the valve body.

8. The digital hydraulic cylinder according to claim 1, characterized in that: A connecting seat is provided at one end of the first ball screw away from the first screw nut, and the first ball screw is fixedly connected to the output end of the driving motor through the connecting seat.

9. The digital hydraulic cylinder according to claim 1, characterized in that: The regulating component also includes a protective shell, which is arranged on a side of the valve body close to the drive motor, and the drive motor, the first ball screw, and the first screw nut are all located in the protective shell.

10. An excavator, characterized in that: It comprises a working arm and a bucket connected to each other, and a digital hydraulic cylinder according to any one of claims 1 to 9, wherein the digital hydraulic cylinder is arranged on the working arm and is drive-connected to the bucket.

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