CN110968114A

CN110968114A - a linear actuator

Info

Publication number: CN110968114A
Application number: CN201911112347.4A
Authority: CN
Inventors: 胡仁昌; 陆小健; 何思韦; 马勇
Original assignee: Zhejiang Jiecang Linear Motion Technology Co Ltd
Current assignee: Zhejiang Jiecang Linear Motion Technology Co Ltd
Priority date: 2019-11-14
Filing date: 2019-11-14
Publication date: 2020-04-07

Abstract

The invention discloses a linear actuator, comprising a casing, a motor arranged in the casing, a controller, a transmission assembly, an outer tube fixed on the casing, and an inner tube arranged in the outer tube. The inner tube is connected to the outer tube. The tubes are slidably connected, and the motor pushes the inner tube to extend or retract the outer tube through the transmission assembly. A distance measuring device is arranged between the inner tube and the outer tube. The distance measuring device includes a magnetic part arranged on the inner tube and a The circuit board is connected with the controller, and the circuit board is provided with a plurality of magnetic force detection devices corresponding to the sliding track of the magnetic piece. The invention converts the measured vertical magnetic field strength into a voltage value and transmits it to the controller through the magnetic force detection device, and the controller calculates the distance of the magnetic piece relative to the initial position through the magnitude and order of the voltage value, that is, calculates the operation position of the inner tube. On this basis, the controller drives the motor to push the inner tube to expand to the specified height, without resetting the inner tube, and the operation is more convenient and quick.

Description

Linear actuator

Technical Field

The invention belongs to the technical field of linear transmission, and particularly relates to a linear actuator.

Background

At present, when the platform that linear actuator promoted need reach a take the altitude, the controller control motor rotates, through the extension of transmission assembly drive inner tube in order to promote the platform to a take the altitude, current linear brake is after the inner tube extension reaches a take the altitude and stops, if situations such as power failure take place, the controller among the linear brake loses the height (the absolute position of inner tube promptly) data of inner tube easily, perhaps the inner tube gliding leads to recording the inner tube height inaccurate in the controller, later stage if the platform need continue to rise to a take the altitude, can only reset linear actuator, extend again in the whole withdrawal outer tubes of inner tube promptly, it is very inconvenient to use.

Disclosure of Invention

The invention aims to provide a linear actuator for measuring a push-out distance.

In order to solve the technical problems, the invention adopts the following technical scheme: a linear actuator comprises a shell, a motor arranged in the shell, a controller, a transmission assembly, an outer tube fixed on the shell and an inner tube arranged in the outer tube, wherein the inner tube is connected with the outer tube in a sliding mode, the motor pushes the inner tube to extend out of or retract into the outer tube through the transmission assembly, a distance measuring device is arranged between the inner tube and the outer tube, the distance measuring device comprises a magnetic part arranged on the inner tube and a circuit board arranged on the outer tube and connected with the controller, and a plurality of magnetic force detection devices are arranged on the circuit board corresponding to sliding tracks of the magnetic part.

Furthermore, the transmission assembly comprises a screw rod driven by the motor, the inner pipe comprises an inner pipe wall and a screw rod nut arranged at the end part of the inner pipe wall, and the screw rod nut is matched with the screw rod.

Furthermore, a mounting groove is formed in the lead screw nut, and the magnetic part is arranged in the mounting groove.

Further, the magnetic member is bonded to the feed screw nut.

Further, the magnetic force detection device is a hall element.

Further, the magnetic member is a permanent magnet.

Compared with the prior art, the invention has the beneficial effects that:

the motor works to drive the transmission assembly to push the inner pipe and the magnetic part to displace together along the axial direction of the inner pipe, so that the inner pipe slides relative to the outer pipe. When the inner pipe does not extend outwards, the position of the magnetic part on the inner pipe is an initial position, the magnetic field intensity detected by a plurality of magnetic detection devices on the circuit board is different, the plurality of magnetic detection devices convert the detected vertical magnetic field intensity into a voltage value and transmit the voltage value to the controller, when the inner pipe slides relative to the outer pipe, the magnetic part on the inner pipe displaces relative to the circuit board, the vertical magnetic field intensity detected by each magnetic detection device is different, the vertical magnetic field intensity detected by each magnetic detection device continuously changes along with the position change of the magnetic part, the magnetic detection devices convert the detected vertical magnetic field intensity into a voltage value and transmit the voltage value to the controller, the controller calculates the distance of the magnetic part relative to the initial position through the size and the sequence of the voltage value, namely calculates the position where the inner pipe operates, so that the controller drives the motor to push the inner pipe to stretch to a specified height on the, the inner tube does not need to be reset, and the operation is more convenient and faster.

Drawings

The invention is further described with reference to the accompanying drawings and the detailed description below:

FIG. 1 is a schematic view of a linear actuator of the present invention;

FIG. 2 is a schematic view of the distance measuring device when the inner tube is not extended out of the outer tube;

FIG. 3 is a schematic view of the device for measuring distance when the inner tube extends outward from the outer tube.

Wherein: 1. a housing; 2. a motor; 3. a transmission assembly; 4. an outer tube; 5. an inner tube; 6. a distance measuring device; 61. a magnetic member; 62. a circuit board; 63. magnetic force detection device.

Detailed Description

An embodiment of a linear actuator of the present invention is further described with reference to fig. 1 to 3.

A linear actuator comprises a shell 1, a motor 2 arranged in the shell 1, a controller, a transmission assembly 3, an outer tube 4 fixed on the shell 1 and an inner tube 5 arranged in the outer tube 4, wherein the inner tube 5 is connected with the outer tube 4 in a sliding mode, the motor 2 pushes the inner tube 5 to extend out of or retract into the outer tube 4 through the transmission assembly 3, a distance measuring device 6 is arranged between the inner tube 5 and the outer tube 4, the distance measuring device 6 comprises a magnetic part 61 arranged on the inner tube 5 and a circuit board 62 arranged on the outer tube 4 and connected with the controller, and a plurality of magnetic force detection devices 63 are arranged on the circuit board 62 corresponding to the sliding track of the magnetic part 61.

The first embodiment is as follows:

a linear actuator is shown in figure 1 and comprises a shell 1, a motor 2, a controller, a transmission assembly 3, an outer tube 4 fixed on the shell 1 and an inner tube 5 arranged in the outer tube 4, wherein the motor 2, the controller and the transmission assembly 3 are arranged in the shell 1, the inner tube 5 is in sliding connection with the outer tube 4, the motor 2 pushes the inner tube 5 to extend out of or retract into the outer tube 4 through the transmission assembly 3, a distance measuring device 6 is arranged between the inner tube 5 and the outer tube 4, the distance measuring device 6 comprises a magnetic part 61 arranged on the inner tube 5 and a circuit board 62 arranged on the outer tube 4 and connected with the controller, and a plurality of magnetic force detection devices 63 are arranged on the circuit board 62 corresponding to the sliding track of the magnetic part 61. The transmission assembly 3 in this embodiment includes a lead screw driven by the motor 2, the inner tube 5 includes a tube wall of the inner tube 5 and a lead screw nut provided at an end of the tube wall of the inner tube 5, and the lead screw nut is engaged with the lead screw. Preferably, the magnetic member 61 is a permanent magnet, which is low in cost, does not demagnetize, and is more stable as the magnetic member 61.

The working principle is as follows:

the motor 2 works to drive the screw rod of the transmission assembly 3 to rotate, the screw rod rotates to enable the screw rod nut matched with the screw rod and the magnetic part 61 on the screw rod nut to displace along the axial direction of the screw rod, and the screw rod nut and the pipe wall of the inner pipe 5 are fixed together, so that the pipe wall of the inner pipe 5 jointly displaces along the axial direction of the screw rod along with the screw rod nut, and the inner pipe 5 slides relative to the outer pipe 4. As shown in fig. 2, when it is determined that the inner tube 5 does not extend out of the outer tube 4, the position of the magnetic member 61 on the inner tube 5 is an initial position, the magnetic field strengths detected by the plurality of magnetic force detection devices 63 on the circuit board 62 are different, the plurality of magnetic force detection devices 63 convert the measured vertical magnetic field strength into a voltage value and transmit the voltage value to the controller, while the inner tube 5 slides relative to the outer tube 4, as shown in fig. 3, the magnetic member 61 on the inner tube 5 is displaced relative to the circuit board 62, the vertical magnetic field strength detected by each magnetic force detection device 63 is different, the vertical magnetic field strength detected by each magnetic force detection device 63 continuously changes with the position change of the magnetic member 61, the magnetic force detection devices 63 convert the measured vertical magnetic field strength into a voltage value and transmit the voltage value to the controller, and the controller calculates the distance of the magnetic member 61 relative to, the position of the inner pipe 5 is calculated, so that the controller drives the motor 2 to push the inner pipe 5 to stretch to a specified height on the basis, the inner pipe 5 does not need to be reset, and the operation is more convenient and faster.

In this embodiment, be equipped with the mounting groove on the feed screw nut, during the mounting groove was located to magnetic part 61, the mounting groove was spacing to magnetic part 61 for magnetic part 61 is more stable, the installation and the dismantlement of the magnetic part 61 of being convenient for. It is understood that the magnetic member 61 may also be bonded to the lead screw nut, facilitating replacement of the magnetic member 61 when the magnetic member 61 is damaged.

It is preferable that magnetic force detection device 63 is the hall element of this embodiment, and the hall element detects different vertical magnetic field intensity because of the distance difference with magnetic part 61, and then outputs different voltage signal and gives the controller, and after the controller calculated magnetic part 61's position, by the flexible of controller drive inner tube 5 again, adopt the hall element as magnetic force detection device 63, have small, the high advantage of measurement accuracy, can accurate measurement inner tube 5's operating position, measuring effect is good.

The above description is only a preferred embodiment of the present invention, and the protection scope of the present invention is not limited to the above embodiments, and all technical solutions belonging to the idea of the present invention belong to the protection scope of the present invention. It should be noted that modifications and embellishments within the scope of the invention may occur to those skilled in the art without departing from the principle of the invention, and are considered to be within the scope of the invention.

Claims

1. A linear actuator, comprising a housing, a motor, a controller, a transmission assembly, an outer tube fixed on the housing, and an inner tube arranged in the outer tube, the inner tube and the The outer tube is slidably connected, and the motor pushes the inner tube to extend or retract the outer tube through the transmission assembly. The magnetic piece on the inner tube and the circuit board arranged on the outer tube and connected with the controller are provided with a plurality of magnetic force detection devices corresponding to the sliding track of the magnetic piece.

2 . The linear actuator according to claim 1 , wherein the transmission assembly comprises a screw rod driven by a motor, and the inner tube comprises an inner tube wall and an end of the inner tube wall. 3 . The lead screw nut of the part is matched with the lead screw.

3 . The linear actuator according to claim 2 , wherein a mounting groove is provided on the screw nut, and the magnetic member is provided in the mounting groove. 4 .

4 . The linear actuator according to claim 2 , wherein the magnetic member is adhered to the screw nut. 5 .

5 . The linear actuator according to claim 1 , wherein the magnetic force detection device is a Hall element. 6 .

6 . The linear actuator according to claim 1 , wherein the magnetic element is a permanent magnet. 7 .