A fully closed-loop high-precision servo electric cylinder

Abstract

The present invention discloses a fully closed-loop high-precision servo electric cylinder, comprising an electric cylinder body and a control system for issuing control instructions thereto, wherein a ball screw, a built-in pressure sensor, a communication module, a coupling, a reducer and a servo motor are sequentially arranged at the upper end of the electric cylinder body from bottom to top, and an end displacement sensor is also arranged in the electric cylinder body for fully closed-loop monitoring of the position in the electric cylinder body; the present invention has a simple structure and is convenient and quick to use, and has a high-precision fully closed-loop control system by arranging a pressure sensor and a magnetic end displacement sensor inside the electric cylinder, and is also equipped with a communication module to integrate all external wirings in the electric cylinder, so that the data signal detected by the sensor can be transmitted by the communication module to the control system for feedback and analysis, thereby accurately reading the position signal of the guide push rod, and the communication module and the control system are connected by a data connection line to avoid transmission interference.

Description

Technical Field

[0001] The present invention relates to the technical field of electric cylinders, and in particular to a full-closed-loop high-precision servo electric cylinder. Background Art

[0002] The servo electric cylinder is a product that integrates a servo motor and a lead screw. By converting the rotational motion of the servo motor into linear motion, it can accurately control the speed, torque, thrust and position. It is a high-precision product.

[0003] The displacement sensor used in the electric cylinder currently available on the market is the rotary encoder that comes with the servo motor. It is a semi-closed control and cannot effectively form a good feedback signal for the parts during the press-fitting process. It is a feedback control mode with low accuracy.

[0004] Most of them use external pressure sensors, which will result in more cables at the end of the push rod. During use, the cables are easily damaged, resulting in inaccurate pressure feedback and damage to the servo electric cylinder. In addition, the external pressure sensor is easily damaged when the electric cylinder loses control, resulting in the need to replace it and re-calibrate it, which requires manpower, material resources and maintenance time, increasing production costs.

[0005] In addition, the guide structure of the existing electric cylinder is to connect a flange at the end of the guide cylinder and then embed it into a copper sleeve. The copper sleeve and the push rod cooperate to control the straightness of the push rod. However, the push rod is easily limited by the thickness of the flange and the length of the copper sleeve, which makes the electric cylinder produce a poor state when controlling the straightness of the push rod. In addition, the end of the push rod is prone to large deflection, which affects the accuracy of use.

[0006] Therefore, it is necessary to study a new technical solution to solve the above problems. Summary of the invention

[0007] In view of this, the present invention aims to solve the deficiencies in the prior art, and its main purpose is to provide a fully closed-loop high-precision servo electric cylinder.

[0008] To achieve the above purpose, the present invention adopts the following technical solutions:

[0009] A fully closed-loop high-precision servo electric cylinder comprises an electric cylinder body and a control system for issuing control instructions thereto, wherein the upper end of the electric cylinder body is provided with a ball screw, a built-in pressure sensor, a communication module, a coupling, a reducer and a servo motor in sequence from bottom to top, and an end displacement sensor is also provided in the electric cylinder body for performing fully closed-loop monitoring of the position in the electric cylinder body, the communication module is electrically connected to the built-in pressure sensor and the end displacement sensor respectively, the servo motor controls the reducer for output transmission, and transmits power to the electric cylinder body through the coupling and the ball screw, thereby causing the guide push rod in the electric cylinder body to perform push-pull motion, the end displacement sensor and the built-in pressure sensor are used to detect the push-out distance and internal pressure value of the electric cylinder body and transmit the monitored data to the control system through the communication module.

[0010] As a preferred embodiment, the electric cylinder body includes an outer shell, a guide cylinder, a guide push rod and a flange fixing block. The guide cylinder and the guide push rod are arranged to be concentrically precisely assembled. Within the stroke range, the guide push rod and the guide cylinder are precisely slidably matched throughout the entire stroke and have full-stroke guiding capabilities. The guide push rod is provided with a sensing element for the end displacement sensor to read the position scale. When the guide push rod moves and changes, the end displacement sensor reads the sensing element at the corresponding position and converts the sensed signal into a pulse value signal, which is transmitted to the communication module and then to the control system to form a closed-loop control; the top end of the guide cylinder is connected to the built-in pressure sensor, and the two are coaxially arranged and generate feedback force when subjected to tension and compression, so that the built-in pressure sensor can accurately feedback the pressure value formed during the tension and compression process.

[0011] As a preferred embodiment, the flange fixing block and the built-in pressure sensor are respectively arranged at the upper and lower ends of the outer shell, and a cavity is formed in the outer shell. One end of the ball screw passes through the center of the built-in pressure sensor and is connected to the coupling, and the other end passes through the top end of the guide push rod and is used to control the movement of the guide push rod. The tail end of the guide push rod passes through the flange fixing block and makes a pushing motion. The guide cylinder is arranged between the guide push rod and the outer shell for allowing the guide push rod to slide along its axial extension direction.

[0012] Preferably, the guide push rod is provided with a rotatable cam, and the cam is horizontally mounted on the upper outer surface of the guide push rod. The guide cylinder is provided with a guide groove for placing the cam, and the guide groove is arranged along the axial direction of the guide cylinder. The outer surface of the cam slides against the inner end surface of the guide groove, and when the guide push rod moves, the cam slides and rolls along the guide groove on the guide cylinder.

[0013] Preferably, a mounting groove is provided at the lower end of the guide cylinder, the end displacement sensor is fixed in the mounting groove and faces the direction of the guide push rod, the sensing element is configured as a magnetic sensing element, the end displacement sensor is located on the outside of the sensing element and is used to sense and detect the position change of the sensing element, thereby analyzing the detected data information and uploading it to the control system via the communication module to obtain the position of the guide push rod.

[0014] Preferably, the sensing element is configured as an inwardly recessed trapezoidal tooth groove located on the outer surface of the guide push rod, the trapezoidal tooth groove is distributed in an array along the axial extension direction of the guide push rod, and the magnetic field signals emitted by the guide push rods at different distances are different, so that the displacement sensor can detect the position signal of the guide push rod and upload it for analysis, and the outer surface of the guide push rod is also provided with a non-magnetic chrome plating layer.

[0015] As a preferred embodiment, the guide push rod is also provided with an external pressure sensor, which is arranged on the end face of the tail end of the guide push rod. The external pressure sensor is used to sense the force borne by touch sensing. The external pressure sensor is connected to the communication module and uploads the measured force for analysis.

[0016] Preferably, a protective shell is further provided on the electric cylinder body, and the protective shell is installed between the built-in pressure sensor and the reduction motor, so as to form a protective chamber therebetween, and the protective chamber is used for placing the coupling therein, and an opening is provided at one side end of the protective shell, and the communication module is embedded and installed in the opening.

[0017] Preferably, the protective shell is further provided with a waterproof side cover, which is arranged at the opening of the protective shell in a flip-opening manner, and a wire hole is provided at the lower end of the waterproof side cover for cables to pass through.

[0018] As a preference, the control system and the communication module are connected by a data transmission line. The communication module is provided with a connection port for plugging the data connection line at the upper end. The communication module uploads the received data signal to the control system via the data transmission line for user viewing.

[0019] Preferably, the end displacement sensor is a coaxial magnetic end displacement sensor, which is used to detect and sense the induction element on the guide push rod, thereby calculating the position information of the guide push rod.

[0020] Compared with the prior art, the present invention has obvious advantages and beneficial effects. Specifically, it can be seen from the above technical scheme that: the present invention has a simple structure and is easy and quick to use. By arranging the pressure sensor and the magnetic end displacement sensor inside the electric cylinder, it has a high-precision full-closed-loop control system. It is also equipped with a communication module to integrate all external wiring in the electric cylinder, so that the data signal detected by the sensor can be transmitted by the communication module to the control system for feedback and analysis, so as to accurately read the position signal of the guide push rod. The communication module and the control system are connected by a data connection line, so that the data information between the two can be accurately and quickly transmitted, avoiding transmission interference, so that the user can view the working data of the electric cylinder in a timely, accurate and fast manner.

[0021] In addition, the use of built-in magnetic end displacement sensors and pressure sensors can effectively reduce the layout of lines and prevent them from being hit by external parts, playing an effective protective role and improving the overall reliability and safety of the electric cylinder.

[0022] A cam is provided on the guide push rod and a guide groove is provided on the guide cylinder, so that the two can abut against each other and rotate and move through the outer surface of the cam and the inner surface of the guide groove, thereby reducing damage to parts, increasing the service life of the electric cylinder, reducing the generation of mechanical noise and reducing the maintenance frequency, further ensuring the operating state of the electric cylinder and good reliability and practicality. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative labor.

[0024] Figure 1 It is a schematic diagram of the overall structure of the present invention.

[0025] Figure 2 It is a schematic diagram of the decomposition structure of the present invention.

[0026] Figure 3 It is a schematic diagram of the structure of the electric cylinder body of the present invention.

[0027] Figure 4 It is a schematic diagram of the exploded structure of the electric cylinder body of the present invention.

[0028] Figure 5 It is a schematic diagram of the guide push rod structure of the present invention.

[0029] Among them, the reference numerals in the figure are:

[0030] 100, electric cylinder body; 110, outer shell; 120, guide cylinder; 121, guide groove; 122, mounting groove; 130, guide push rod; 131, cam; 132, induction component; 140, flange fixing block; 200, ball screw; 300, built-in pressure sensor; 310, external pressure sensor; 400, communication module; 500, coupling; 600, reducer; 700, servo motor; 800, end displacement sensor; 900, protective shell; 910, opening; 920, waterproof side cover; 930, wire hole; 940, data transmission line. DETAILED DESCRIPTION

[0031] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present application more clearly understood, the present application is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present application and are not used to limit the present application.

[0032] It should be noted that when an element is referred to as being "fixed to" or "disposed on" another element, it can be directly on the other element or indirectly on the other element. When an element is referred to as being "connected to" another element, it can be directly connected to the other element or indirectly connected to the other element.

[0033] It should be understood that the terms "length", "width", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0034] 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. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of the features. In the description of this application, the meaning of "plurality" is two or more, unless otherwise clearly and specifically defined.

[0035] In order to make the purpose, technical solutions and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments.

[0036] Reference Figure 1-5As shown: a fully closed-loop high-precision servo electric cylinder, including an electric cylinder body 100 and a control system (not marked in the figure) for controlling instructions below it, by arranging a ball screw 200, a built-in pressure sensor 300, a communication module 400, a coupling 500, a reducer 600 and a servo motor 700 in sequence from bottom to top at the upper end of the electric cylinder body 100, and an end displacement sensor 800 is also arranged in the electric cylinder body 100, so that the electric cylinder body 100 can realize full closed-loop position monitoring, and the position information of the electric cylinder body 100 can be obtained in time and effectively, and the communication module 400 is electrically connected to the built-in pressure sensor 300, the end displacement sensor 800 and the control system respectively, so that the data information detected by them can be transmitted to the control system by the communication module 400.

[0037] Specifically, the servo motor 700 is operated, and then the output transmission is performed by controlling the reducer 600, and then the power is transmitted to the electric cylinder body 100 through the coupling 500 and the ball screw 200, so that the guide push rod 130 in the electric cylinder body 100 performs a push-pull movement. In addition, during the movement, the end displacement sensor 800 and the built-in pressure sensor 300 are used to detect the push-out distance of the electric cylinder body 100 and the change of the internal pressure value, and the monitored data is timely transmitted to the control system through the communication module 400 for analysis and processing.

[0038] In this embodiment, the electric cylinder body 100 includes an outer shell 110, a guide cylinder 120, a guide push rod 130 and a flange fixing block 140. The guide cylinder 120 and the guide push rod 130 are arranged to be concentrically precisely assembled, so that the two can be precisely slidably matched throughout the stroke range and have full stroke guiding capability. In addition, a sensing element 132 for the end displacement sensor 800 to read the position scale is provided on the guide push rod 130. When the guide push rod 130 moves, the end displacement sensor 800 will read the corresponding position. The sensing element 132 senses the magnetic field signal, and then converts the sensed signal into a pulse value signal and transmits it to the communication module 400, which then transmits the data to the control system for analysis, so that the electric cylinder body 100 forms a closed-loop control; the top of the guide cylinder 120 is connected to the built-in pressure sensor 300, so that the two are coaxially arranged and generate feedback force when they are pulled or compressed, so that the built-in pressure sensor 300 can accurately feedback the pressure value formed during the pulling and pressing process, and transmit it to the communication module 400 and then to the control system for analysis and processing.

[0039] Specifically, the flange fixing block 140 and the built-in pressure sensor 300 are respectively arranged at the left and right ends of the outer shell 110, and a cavity is formed inside the outer shell 110, and then one end of the ball screw 200 is passed through the center of the built-in pressure sensor 300 and connected to the coupling 500, and then the other end is passed through the top of the guide push rod 130, and the ball screw 200 can control the guide push rod 130 to move, and then the tail end of the guide push rod 130 is passed through the flange fixing block 140 and moves; wherein, the guide cylinder 120 is arranged Between the guide push rod 130 and the outer shell 110, the guide push rod 130 can slide precisely along the axial extension direction of the guide cylinder 120; during use, when the ball screw 200 controls the guide push rod 130 to slide, the built-in pressure sensor 300 can monitor the pressure value change of the electric cylinder body 100, and read the position information of the sensing element 132 through the end displacement sensor 800, and upload the corresponding data signal to the control system through the communication module 400 for data analysis, so as to determine the specific position of the guide push rod 130.

[0040] Furthermore, an angular contact bearing is provided between the ball screw 200 and the built-in pressure sensor 300, so that the upper end of the inner ring of the angular contact bearing abuts against the rear end of the ball screw 200 for force, and the lower end of the inner ring of the angular contact bearing abuts against the built-in pressure sensor 300, so that when the ball screw 200 moves backward, it abuts against the upper end surface of the angular contact bearing, so that the inner ring of the angular contact bearing is subjected to pressure, and then the lower end surface of the angular contact bearing transmits the pressure it is subjected to to the built-in pressure sensor 300, so that the built-in pressure sensor 300 can detect the corresponding pressure value change, and the measured data signal is transmitted from the communication module 400 to the control system for data analysis.

[0041] In this embodiment, a rotatable cam 131 is further provided on the guide push rod 130, and the cam 131 is horizontally installed on the outer surface of the guide push rod 130, and a guide groove 121 for placing the cam 131 is opened on the guide cylinder 120, and the guide groove 121 is set along the axial direction of the guide cylinder 120 and the guide distance is extended backward, so that during assembly, the outer surface of the cam 131 slides against the inner end surface of the guide groove 121, so that when the guide push rod 130 moves, the cam 131 slides and rolls along the guide groove 121 on the guide cylinder 120, so that the outer surface of the guide push rod 130 can maintain a certain distance from the inner wall of the guide cylinder 120 to avoid friction, etc., effectively protect the rigidity between the two, and can also improve the pushing accuracy of the guide push rod 130 and reduce the assembly of parts.

[0042] Furthermore, by providing a sealing ring at the movable part of the guide push rod 130 and the guide cylinder 120 , internal oil leakage can be effectively prevented, and external dust can be prevented from entering the interior, thereby affecting the service life of the electric cylinder body 100 .

[0043] Furthermore, a mounting groove 122 is provided at the lower end of the guide cylinder 120, and the end displacement sensor 800 is installed and fixed in the mounting groove 122, and the end displacement sensor 800 is oriented in the direction of the guide push rod 130. The sensing element 132 used is a magnetic sensing element 132, which is set in the axial extension direction of the guide push rod 130, and then the end displacement sensor 800 is located on the outside of the sensing element 132, and during the movement of the guide push rod 130, the end displacement sensor 800 can sense and detect the change in the position of the magnetic field on the sensing element 132, so that the detected data information is uploaded to the control system 400 via the communication module 400, and the accurate position of the guide push rod 130 is obtained.

[0044] Specifically, the sensing element 132 is a trapezoidal tooth groove that is recessed inward on the outer surface of the guide push rod 130. The trapezoidal tooth groove is distributed in an array along the axial extension direction of the guide push rod 130, and the magnetic field signals emitted by the guide push rods 130 at different distances are different, so that the end displacement sensor 800 can detect the position signal of the guide push rod 130 and upload it. In addition, a non-magnetic chrome-plated layer is provided on the outer surface of the guide push rod 130 to protect the trapezoidal tooth groove from wear and tear, and to avoid the magnetic relationship between the two due to long-term reciprocating motion in the guide cylinder 120, thereby affecting the induced magnetic field of the guide push rod 130.

[0045] In this embodiment, an external pressure sensor 310 is also provided on the guide push rod 130. The external pressure sensor 310 is set on the end face of the tail end of the guide push rod 130, so that the external pressure sensor 310 can touch the object during use to sense the force it is subjected to, and the external pressure sensor 310 is connected to the communication module 400. The measured data signal is transmitted by the communication module 400 to the control system for analysis through the external pressure sensor 310, and a more accurate position can be measured in combination with other sensors.

[0046] In this embodiment, a protective shell 900 is further provided on the electric cylinder body 100. The protective shell 900 is installed between the built-in pressure sensor 300 and the reduction motor to form a protective chamber therebetween. The coupling 500 can be placed in the protective chamber to protect the coupling 500. An opening 910 is provided at one side end of the protective shell 900 to allow the communication module 400 to be embedded and installed in the opening 910. The connecting lines of the end displacement sensor 800, the built-in pressure sensor 300 and the external pressure sensor 310 are all laid from the inside to reduce leakage of the lines and avoid damage to the wiring harness during use, thereby affecting the use.

[0047] Furthermore, a waterproof side cover 920 is provided on the protective shell 900, and the waterproof side cover 920 is set at the opening 910 of the protective shell 900 in a flip-opening and closing manner. A wire hole 930 is also provided at the lower end of the waterproof side cover 920 to facilitate the cable to pass through from the lower end and connect to the internal communication module 400.

[0048] Furthermore, a data transmission line 940 is used to connect the control system and the communication module 400, and a connection port is provided on the communication module 400 for plugging a data connection line at the upper end, wherein the data connection line can be a network connection line or a high-speed transmission line, so that the data signal received by the communication module 400 is uploaded to the control system through the data transmission line 940, so that the data can be quickly and accurately transmitted to the control system for analysis and processing, and the user can view the position and operating status of the electric cylinder body 100.

[0049] Specifically, the end displacement sensor 800 used is a coaxial magnetic end displacement sensor 800, which can detect and sense the sensing element 132 on the guide push rod 130, thereby calculating the accurate position information of the guide push rod 130, thereby realizing a fully enclosed high-precision servo electric cylinder.

[0050] The above are only preferred embodiments of the present invention, and only specifically describe the technical principles of the present invention. These descriptions are only for explaining the principles of the present invention and cannot be interpreted as limiting the scope of protection of the present invention in any way. Based on the explanations here, any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention, and other specific implementations of the present invention that can be associated with by technicians in this field without creative labor, should be included in the scope of protection of the present invention.

Claims

1. A fully closed-loop high-precision servo electric cylinder, comprising an electric cylinder body and a control system for issuing control instructions thereto, characterized in that: The upper end of the electric cylinder body is provided with a ball screw, a built-in pressure sensor, a communication module, a coupling, a reducer and a servo motor in sequence from bottom to top. The electric cylinder body is also provided with an end displacement sensor for performing full closed-loop monitoring of the position inside the electric cylinder body. The communication module is electrically connected to the built-in pressure sensor, the end displacement sensor and the control system respectively. The servo motor controls the reducer for output transmission, and transmits power to the electric cylinder body through the coupling and the ball screw, so that the guide push rod in the electric cylinder body performs push-pull motion. The end displacement sensor and the built-in pressure sensor are used to detect the push-out distance and internal pressure value of the electric cylinder body and transmit the monitored data to the control system through the communication module; The electric cylinder body includes an outer shell, a guide cylinder, a guide push rod and a flange fixing block. The guide cylinder and the guide push rod are arranged to be concentrically precisely assembled. Within the stroke range, the guide push rod and the guide cylinder are precisely slidably matched throughout the entire stroke and have full-stroke guiding capabilities. The guide push rod is provided with a sensing piece for the end displacement sensor to read the position scale. When the guide push rod moves and changes, the end displacement sensor reads the sensing piece at the corresponding position and converts the sensed signal into a pulse value signal, which is transmitted to the communication module and then to the control system to form a closed-loop control; the top end of the guide cylinder is connected to the built-in pressure sensor, and the two are arranged coaxially and generate feedback force when subjected to tension and compression, so that the built-in pressure sensor can accurately feedback the pressure value formed during the tension and compression process.

2. The fully closed-loop high-precision servo electric cylinder according to claim 1 is characterized in that: The guide push rod is provided with a rotatable cam, and the cam is horizontally installed on the outer surface of the guide push rod. The guide cylinder is provided with a guide groove for the cam to be placed therein, and the guide groove is arranged along the axial direction of the guide cylinder. The outer surface of the cam slides against the inner end surface of the guide groove. When the guide push rod moves, the cam slides and rolls along the guide groove on the guide cylinder.

3. The fully closed-loop high-precision servo electric cylinder according to claim 1 is characterized in that: The lower end of the guide cylinder is provided with a mounting groove, the end displacement sensor is installed and fixed in the mounting groove and faces the direction of the guide push rod, the sensing element is configured as a magnetic sensing element, the end displacement sensor is located outside the sensing element and is used to sense and detect the position change of the sensing element, thereby analyzing the detected data information and uploading it to the control system via the communication module to obtain the position of the guide push rod.

4. The fully closed-loop high-precision servo electric cylinder according to claim 3 is characterized in that: The sensing element is configured as an inwardly recessed trapezoidal tooth groove located on the outer surface of the guide push rod. The trapezoidal tooth groove is distributed in an array along the axial extension direction of the guide push rod, and the magnetic field signals emitted by the guide push rods at different distances are different, so that the displacement sensor can detect the position signal of the guide push rod and analyze and upload it. The outer surface of the guide push rod is also provided with a non-magnetic chrome plating layer.

5. The fully closed-loop high-precision servo electric cylinder according to claim 1 is characterized in that: The guide push rod is also provided with an external pressure sensor, which is arranged on the end face of the tail end of the guide push rod. The external pressure sensor is used to sense the force borne by touch sensing. The external pressure sensor is connected to the communication module and uploads the measured force for analysis.

6. The fully closed-loop high-precision servo electric cylinder according to claim 1 is characterized in that: The control system and the communication module are connected by a data transmission line. The communication module is provided with a connection port for inserting the data connection line at the upper end. The communication module uploads the received data signal to the control system through the data transmission line for user viewing.

7. The fully closed-loop high-precision servo electric cylinder according to claim 3 is characterized in that: The end displacement sensor is a coaxial magnetic end displacement sensor, which is used to detect and sense the induction element on the guide push rod, thereby calculating the position information of the guide push rod.

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