Electric linear actuator

Abstract

The present invention relates to the technical field of electric push rods, and in particular to an electric push rod, comprising a stepper motor, a screw, a nut, a transmission seat, a force rod and a pressure detection sensor; the stepper motor, as a driving source, can drive the screw to rotate around its own axis, and then drive the nut to make linear reciprocating motion along the axis of the screw, thereby driving the transmission seat and the force rod to make linear reciprocating motion, and one end face of the force rod can apply a preset pressure to the workpiece. Compared with the form of servo motor as a driving source, the manufacturing cost and maintenance cost are lower. The force rod and the transmission seat are connected by an elastic connection method, instead of the traditional rigid connection form, which can achieve the purpose of spontaneous position compensation, and convert the position adjustment from step-by-step adjustment to stepless adjustment, which is more conducive to accurately controlling the pressure applied by the force rod to the workpiece, and achieves the purpose of stably applying more accurate pressure to the workpiece at a lower cost.

Description

Technical Field

[0001] The present invention relates to the technical field of electric push rods, and in particular to an electric push rod. Background Art

[0002] The production line of wireless Bluetooth headsets and headset boxes involves the parts assembly process. During the parts assembly process, it is necessary to apply a rated pressure to the workpiece and maintain the pressure for a certain period of time to ensure that the assembly process is carried out stably. Excessive pressure causes deformation of the parts, affecting the product yield. If the pressure is too low, there is a risk of poor contact between the parts, which will also affect the product yield. Therefore, how to achieve the purpose of applying more precise pressure to the workpiece at a lower cost has become a technical problem that needs to be solved urgently by those skilled in the art. Summary of the invention

[0003] The present invention provides an electric push rod for solving the problem of how to achieve the purpose of applying relatively accurate pressure to a workpiece at a relatively low cost.

[0004] In one aspect, the present invention provides an electric linear actuator, comprising:

[0005] Stepper motor;

[0006] A lead screw, one end of which is fixedly connected to the output shaft of the stepper motor;

[0007] The nut is sleeved on the screw rod and can perform linear reciprocating motion along the axis of the screw rod;

[0008] The transmission seat is fixedly connected to the nut and can perform linear reciprocating motion with the nut;

[0009] The force-applying rod is arranged in parallel with the lead screw, is elastically connected to the transmission seat, can perform linear reciprocating motion with the transmission seat, and one end surface is used to apply pressure to the workpiece;

[0010] The pressure detection sensor is installed on the force application rod.

[0011] In some embodiments, it also includes:

[0012] A limiting ring is sleeved on the middle part of the force application rod;

[0013] The spring is sleeved on the middle part of the force-applying rod, one end of which is connected to the limiting ring, and the other end of which is connected to the transmission seat.

[0014] In some embodiments, it also includes:

[0015] A limiting ring is sleeved on the middle part of the force application rod;

[0016] Shape memory alloy, installed between the limit ring and the transmission seat.

[0017] In some of the embodiments, one side of the limiting ring has an opening structure.

[0018] In some embodiments, the force application rod includes a first rigid connection section, a flexible connection section, and a second rigid connection section connected in sequence; a fluid temporary storage cavity is formed inside the flexible connection section; and the flexible connection section is connected to the transmission seat.

[0019] In some embodiments, a clearance hole for the screw rod to pass through is provided at one end of the transmission seat, and a clearance groove for the force application rod to pass through is provided at the other end;

[0020] The top and the bottom of the middle part of the force-applying rod are respectively provided with limited rotation grooves to limit the force-applying rod from rotating around its own axis.

[0021] In some embodiments, it also includes:

[0022] The shell has a partition inside and an end plate at one end; a stepper motor is detachably mounted on the side of the partition away from the end plate; a first guide hole is provided on the partition for one end of the force rod to pass through; and a second guide hole is provided on the end plate for the other end of the force rod to pass through.

[0023] In some embodiments, it also includes:

[0024] A first guide sleeve is installed in the first guide hole;

[0025] The second guide sleeve is installed in the second guide hole.

[0026] In some embodiments, it also includes:

[0027] The connecting ring is sleeved on one end of the force-applying rod, and a pressure detection sensor is installed on one end surface.

[0028] In some embodiments, it also includes:

[0029] The controller is connected with the stepping motor and the pressure detection sensor respectively.

[0030] The beneficial effects of the present invention are as follows: the electric push rod of the present invention is provided with a pressure detection sensor, and the pressure detection sensor is used to detect the pressure applied by the force rod to the workpiece. The stepper motor is used as a driving source, which can drive the screw rod to rotate around its own axis, and then drive the nut to make a linear reciprocating motion along the axis of the screw rod, thereby driving the transmission seat and the force rod to make a linear reciprocating motion, and one end face of the force rod can apply a preset value of pressure to the workpiece. Compared with the form of a servo motor as a driving source, the manufacturing cost and maintenance cost are lower. The use of a screw rod and a nut to convert rotary motion into linear motion has a long service life, less resistance to transmission, high transmission stability, and low transmission cost. The force rod and the transmission seat are connected by an elastic connection method, instead of the traditional rigid connection method, which can achieve the purpose of spontaneous position compensation, and convert the position adjustment from step-by-step adjustment to stepless adjustment, which is more conducive to accurately controlling the pressure applied by the force rod to the workpiece, and achieves the purpose of stably applying a more accurate pressure to the workpiece at a lower cost. In addition, compared with the method of applying pressure with a cylinder or hydraulic cylinder, there is no need to use battery valves, pressure reducing valves, relays, etc. to build a pressure control system, which reduces the use of parts and saves costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 It is a structural schematic diagram of some specific embodiments of an electric linear actuator of the present invention;

[0032] Figure 2 yes Figure 1 The schematic diagram of the structure of the electric linear actuator from another perspective is shown;

[0033] Figure 3 yes Figure 1 A top view of the electric actuator shown;

[0034] Figure 4 yes Figure 1 The schematic structural diagrams of some specific embodiments of the force-applying rod in the electric push rod are shown;

[0035] Figure 5 Schematic diagram of the structure of other embodiments of the force application rod.

[0036] In the accompanying drawings, 110, stepper motor; 120, screw rod; 130, nut; 140, transmission seat; 150, force rod; 151, rotation limiting groove; 152, first rigid connection section; 153, flexible connection section; 154, second rigid connection section; 160, pressure detection sensor; 170, limit ring; 180, spring; 191, partition; 192, first guide sleeve; 193, second guide sleeve; 194, connecting ring. DETAILED DESCRIPTION

[0037] The technical solution of the present invention will be clearly and completely described below in conjunction with the embodiments. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all of the embodiments. 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.

[0038] As described in the background technology, the production line of wireless Bluetooth headsets and headset boxes involves a parts assembly process. During the parts assembly process, it is necessary to apply a rated pressure to the workpiece and maintain the pressure for a certain period of time to ensure that the assembly process is carried out stably. Excessive pressure causes deformation of the parts, affecting the product yield. If the pressure is too low, there is a risk of poor contact between the parts, which will also affect the product yield. Therefore, how to achieve the purpose of applying more precise pressure to the workpiece at a lower cost has become a technical problem that needs to be solved urgently by those skilled in the art.

[0039] To solve the above problems, refer to Figure 1 , Figure 2 , Figure 3 , Figure 4 and Figure 5The present invention provides an electric push rod, including a stepping motor 110, a screw rod 120, a nut 130, a transmission seat 140, a force rod 150 and a pressure detection sensor 160. One end of the screw rod 120 is fixedly connected to the output shaft of the stepping motor 110. The nut 130 is sleeved on the screw rod 120 and can make linear reciprocating motion along the axis of the screw rod 120. The transmission seat 140 is fixedly connected to the nut 130 and can make linear reciprocating motion with the nut 130. The force rod 150 is arranged in parallel with the screw rod 120, elastically connected to the transmission seat 140, and can make linear reciprocating motion with the transmission seat 140, and one end face is used to apply pressure to a workpiece. The pressure detection sensor 160 is installed on the force rod 150, and is used to detect the pressure applied by the force rod 150 to the workpiece. The stepper motor 110, as a driving source, can drive the screw 120 to rotate around its own axis, and then drive the nut 130 to make linear reciprocating motion along the axis of the screw 120, thereby driving the transmission seat 140 and the force rod 150 to make linear reciprocating motion, and one end face of the force rod 150 can apply a preset pressure to the workpiece. Compared with the form of a servo motor as a driving source, the manufacturing cost and maintenance cost are lower. The use of the screw 120 and the nut 130 to convert rotational motion into linear motion has a long service life, less resistance to transmission, high transmission stability, and low transmission cost. Due to the step angle characteristics of the stepper motor 110, the transmission component has a certain transmission error. Therefore, an elastic connection is introduced between the driving source and the output end, that is, the force rod 150 and the transmission seat 140 are connected by an elastic connection method, replacing the traditional rigid connection form, which can achieve the purpose of spontaneous position compensation, and convert the position adjustment from step-by-step adjustment to stepless adjustment, which is more conducive to accurately controlling the pressure applied by the force rod 150 to the workpiece, and achieves the purpose of stably applying more accurate pressure to the workpiece at a lower cost. In addition, compared with the method of applying pressure by a cylinder or a hydraulic cylinder, there is no need to build a pressure control system with the help of a battery valve, a pressure reducing valve, and a relay, which reduces the use of parts and saves costs.

[0040] In some practical applications, the electric push rod also includes a limit ring 170, a spring 180 and a controller. The limit ring 170 is fixedly sleeved on the middle part of the force rod 150. The spring 180 is sleeved on the middle part of the force rod 150, one end of which is fixedly connected to the limit ring 170, and the other end is fixedly connected to the transmission seat 140. With the characteristic that the spring 180 can be deformed, the purpose of spontaneous position compensation is achieved, which is more conducive to accurately controlling the position of the force rod 150 and the pressure applied by the force rod 150 to the workpiece. The controller is electrically connected to the stepper motor 110 and the pressure detection sensor 160 respectively. The pressure detection sensor 160 detects the pressure applied by the force rod 150 to the workpiece and feeds it back to the controller, and the controller controls whether the stepper motor 110 is working.

[0041] In other practical applications, the electric push rod also includes a limit ring 170, a shape memory alloy and a controller. The limit ring 170 is fixedly sleeved on the middle part of the force rod 150. The shape memory alloy is installed between the limit ring 170 and the transmission seat 140. The shape memory alloy can undergo plastic deformation within a certain temperature range and can recover the deformation within another temperature range. The controller is electrically connected to the stepper motor 110, the pressure detection sensor 160, and the shape memory alloy respectively. The pressure detection sensor 160 detects the pressure applied by the force rod 150 to the workpiece and feeds it back to the controller, which controls whether the stepper motor 110 and the shape memory alloy are working. When the shape memory alloy is not working, the transmission seat 140 and the force rod 150 are rigidly connected. When the shape memory alloy is required to participate in the pressure regulation task, the transmission seat 140 and the force rod 150 are elastically connected to meet more working conditions.

[0042] In some other applications, the electric push rod is not provided with the limit ring 170, the spring 180 and the shape memory alloy. Figure 5 As shown, the force-applying rod 150 includes a first rigid connection section 152, a flexible connection section 153, and a second rigid connection section 154 which are connected in sequence. The flexible connection section 153 is a bellows made of rubber or silicone and can deform to a certain extent. A fluid storage chamber is formed inside the flexible connection section 153. The flexible connection section 153 is fixedly connected to the transmission seat 140 so that the force-applying rod 150 and the transmission seat 140 are elastically connected. Inputting different volumes of fluids such as liquid or gas into the fluid storage chamber can change the rigidity of the flexible connection section 153, so that the flexible connection section 153 has different elastic coefficients to meet more working conditions.

[0043] Preferably, one side of the limiting ring 170 has an open structure, so that it is convenient to install, use, disassemble and replace the limiting ring 170. A locking nut is arranged on the open side of the limiting ring 170 to prevent the limiting ring 170 from falling off from the force rod 150.

[0044] Preferably, a clearance hole for the screw rod 120 to pass through is provided at one end of the transmission seat 140, and a clearance groove for the force application rod 150 to pass through is provided at the other end. The clearance groove is a C-shaped structure. Figure 4 As shown, limited rotation grooves 151 are respectively provided at the top and bottom of the middle part of the force-applying rod 150, the limit groove at the top contacts the top wall of the clearance groove, and the limit groove at the bottom contacts the bottom wall of the clearance groove, so as to limit the force-applying rod 150 from rotating around its own axis. In this way, the force-applying rod 150 is effectively prevented from rotating with the workpiece, and the force-applying rod 150 is guaranteed to apply stable pressure to the workpiece.

[0045] Specifically, in the exemplary embodiment, the electric push rod also includes a shell, which can protect the stepper motor 110, the screw rod 120, the nut 130, the transmission seat 140 and the force rod 150, thereby extending their service life. A partition 191 is provided inside the shell, and an end plate is provided at one end. The stepper motor 110 is detachably mounted on the side surface of the partition 191 facing away from the end plate. A first guide hole is provided on the partition 191 for one end of the force rod 150 to pass through. A second guide hole is provided on the end plate for the other end of the force rod 150 to pass through. The first guide hole and the second guide hole cooperate with each other to guide the moving direction of the force rod 150, and at the same time, can constrain the force rod 150 from shaking up and down and left and right, thereby ensuring the stability of the applied pressure.

[0046] Preferably, the stepper motor 110 is detachably connected to the partition plate 191 via screws.

[0047] Preferably, the electric push rod further includes a first guide sleeve 192 and a second guide sleeve 193. The first guide sleeve 192 is installed in the first guide hole, which can effectively reduce the degree of wear between the partition plate 191 and the force rod 150, and extend the service life of the force rod 150. The second guide sleeve 193 is installed in the second guide hole, which can effectively reduce the degree of wear between the end plate and the force rod 150, and extend the service life of the force rod 150.

[0048] Specifically, in the exemplary embodiment, the electric push rod further includes a connecting ring 194. The connecting ring 194 is fixedly sleeved on one end of the force rod 150, and a pressure detection sensor 160 is installed on one end surface. The connecting ring 194 effectively increases the contact area when the pressure detection sensor 160 is connected to the force rod 150, and improves the stability of the connection between the pressure detection sensor 160 and the force rod 150. Installing the pressure detection sensor 160 at the position where the force rod 150 contacts the workpiece is more direct, accurate and reliable than installing it at other positions.

[0049] Preferably, one side of the connecting ring 194 has an open structure, so that it is convenient to install, use, disassemble and replace the connecting ring 194. A locking nut is arranged on the open side of the connecting ring 194 to prevent the connecting ring 194 from falling off from the force applying rod 150.

[0050] It should be noted that, in order to achieve the position compensation function, an elastic member such as a spring 180 may be provided between the connecting ring 194 and the pressure detection sensor 160 , or an elastic member such as a spring 180 may be provided at the connection between the nut 130 and the transmission seat 140 .

[0051] 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.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. An electric push rod, characterized in that: include: Stepper motor; A screw rod, one end of which is fixedly connected to the output shaft of the stepping motor; A nut, sleeved on the screw rod, capable of performing linear reciprocating motion along the axis of the screw rod; A transmission seat, fixedly connected to the nut and capable of linear reciprocating motion with the nut; A force-applying rod, arranged in parallel with the screw rod, elastically connected to the transmission seat, capable of linear reciprocating motion with the transmission seat, and having one end surface used for applying pressure to the workpiece; A pressure detection sensor is installed on the force application rod; The force-applying rod comprises a first rigid connection section, a flexible connection section and a second rigid connection section which are connected in sequence; a fluid temporary storage cavity is formed inside the flexible connection section; and the flexible connection section is connected to the transmission seat.

2. The electric linear actuator according to claim 1, characterized in that: One end of the transmission seat is provided with a clearance hole for the screw rod to pass through, and the other end is provided with a clearance groove for the force application rod to pass through; The top and the bottom of the middle part of the force applying rod are respectively provided with limited rotation grooves to limit the force applying rod from rotating around its own axis.

3. The electric linear actuator according to claim 1, characterized in that: Also includes: The shell has a partition plate inside and an end plate at one end; the stepper motor is detachably mounted on a side surface of the partition plate facing away from the end plate; a first guide hole is provided on the partition plate for one end of the force rod to pass through; and a second guide hole is provided on the end plate for the other end of the force rod to pass through.

4. The electric linear actuator according to claim 3, characterized in that: Also includes: A first guide sleeve, installed in the first guide hole; The second guide sleeve is installed in the second guide hole.

5. The electric linear actuator according to claim 4, characterized in that: Also includes: The connecting ring is sleeved on one end of the force-applying rod, and the pressure detection sensor is installed on one end surface.

6. The electric linear actuator according to claim 1, characterized in that: Also includes: The controller is connected to the stepping motor and the pressure detection sensor respectively.

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