Transmission mechanism of an electrically controlled actuator and method for manufacturing the same

Abstract

This invention provides a transmission mechanism for an electronically controlled actuator and its manufacturing method. The transmission mechanism includes a transmission nut, which comprises: a hollow tube with a plurality of spaced-apart glue-passing holes on its wall; an injection-molded nut disposed within the hollow tube; and a plurality of limiting structures, each filling one of the glue-passing holes. The limiting structures and the injection-molded nut are integrally formed by a single injection molding process within the hollow tube. Compared to existing technologies, this invention separates the injection molding of the nut and the rotor housing. Separate injection molding of the nut simplifies the mold structure, reduces cost, and facilitates mass production. The simplified structure also optimizes the mold design, making it easier to ensure the dimensional accuracy of the nut, thereby improving the transmission accuracy of the lead screw nut.

Description

[Technical Field]

[0001] This invention relates to the field of actuator technology, and in particular to a transmission mechanism for an electronically controlled actuator and its manufacturing method. [Background Technology]

[0002] A car turbocharger uses the inertial force of the exhaust gas from the engine to drive the turbine to rotate. At the same time, the turbine drives the coaxial impeller, which compresses the fresh air delivered by the air filter, increasing its pressure before it enters the cylinder.

[0003] When boost pressure is not needed or exceeds the required pressure, some exhaust gas will be discharged through the bypass valve instead of entering the turbocharger. In this case, an actuator is needed to precisely control the opening of the exhaust bypass valve in real time according to actual needs, thereby accurately and reasonably controlling the turbine speed and ultimately achieving the most ideal intake pressure control.

[0004] Linear displacement electric actuators are driven by a lead screw and nut. Traditionally, the drive nut and rotor are injection molded together with a plastic insulating layer in a single process. However, due to the special location of the injection port in this process, the nut deforms significantly after injection molding. To ensure the frictional torque, the clearance between the lead screw and nut needs to be increased, resulting in excessive tooth backlash, which affects customer use. Furthermore, injection molding the nut and rotor with the plastic insulating layer in a single process results in a complex mold structure, which is not conducive to mass production.

[0005] The main problem with single injection molding is the complexity of the rotor's outer plastic structure, which makes it difficult to place the gate of the drive nut in the most ideal position. This makes it difficult for the plastic to enter and fill the cavity quickly, and to cool and seal it in time after filling. This results in quality defects such as shrinkage cavities, material shortages, white spots, weld lines, brittleness, decomposition, and warping.

[0006] Existing competitors use a one-time injection molding process for the nut and rotor housing. This method results in a very complex mold structure, and the complex structure makes the product prone to deformation after injection molding, affecting the accuracy of transmission.

[0007] Therefore, it is necessary to propose a new type of transmission mechanism for electronically controlled actuators and its manufacturing method. [Summary of the Invention]

[0008] One of the objectives of this invention is to provide a transmission mechanism for an electronically controlled actuator and its manufacturing method, which simplifies the mold structure and facilitates design and manufacturing by molding a nut in a single injection (or separately) inside a hollow rotor tube (or hollow tube).

[0009] According to one aspect of the present invention, the present invention provides a transmission mechanism for an electronically controlled actuator, comprising a transmission nut, the transmission nut comprising: a hollow tube having a plurality of glue-passing holes arranged at intervals on its wall; an injection-molded nut disposed within the hollow tube; and a plurality of limiting structures respectively filling the plurality of glue-passing holes, wherein the plurality of limiting structures and the injection-molded nut are integrally formed by injection molding in the hollow tube in a single process.

[0010] Furthermore, the transmission nut also includes: a plurality of anti-tension structures disposed on the outer surface of the tube wall of the hollow tube; a plurality of anti-rotation structures disposed on the outer surface of the tube wall of the hollow tube; wherein the plurality of limiting structures, the plurality of anti-tension structures, the plurality of anti-rotation structures and the injection-molded nut are integrally formed by injection molding in the hollow tube in one step.

[0011] Furthermore, the anti-stretching structure is a boss; the anti-rotation structure is a four-sided anti-rotation structure.

[0012] Furthermore, the plurality of anti-stretching structures and the plurality of anti-rotation structures are located in the middle of the tube wall of the hollow tube; the plurality of anti-stretching structures and the plurality of anti-rotation structures are arranged alternately along the circumferential direction on the outer surface of the tube wall of the hollow tube.

[0013] Furthermore, the transmission mechanism of the electronically controlled actuator also includes: a rotor core, wherein the transmission nut is sleeved inside the rotor core; and a secondary injection molding structure in which the transmission nut and the rotor core, which are sleeved together, are injection molded together.

[0014] According to another aspect of the present invention, the present invention provides a method for manufacturing a transmission mechanism of an electronically controlled actuator, comprising: providing a hollow tube, wherein a plurality of glue-passing holes are provided on the tube wall of the hollow tube at intervals; providing a threaded core puller and a slider, wherein the threaded core puller and the slider are arranged sequentially along the axial direction of the hollow tube inside the hollow tube to form a first cavity surrounding the sidewall of the threaded core puller and the sidewall of the slider inside the hollow tube; providing an annular mold, wherein the annular mold is sleeved on the outside of the tube body of the hollow tube to form a second cavity surrounding the hollow tube between the annular mold and the tube wall of the hollow tube, and the first cavity and the second cavity are connected through the glue-passing holes; and obtaining a transmission nut by performing a single injection molding into the hollow tube and the annular mold.

[0015] Furthermore, the annular mold is provided with a glue inlet; the drive nut is obtained by injection molding into the hollow tube and the annular mold through the glue inlet on the annular mold.

[0016] Furthermore, the transmission nut includes the hollow tube, the injection-molded nut, several limiting structures, several anti-stretching structures, and several anti-rotation structures. The injection-molded nut is formed by plastic material injected into the first cavity; the several limiting structures are formed by plastic material injected into the several through holes; and the several anti-stretching structures and several anti-rotation structures are formed by plastic material injected into the second cavity.

[0017] Furthermore, the anti-stretching structure is a boss; the anti-rotation structure is a four-sided anti-rotation structure.

[0018] Furthermore, the plurality of anti-stretching structures and the plurality of anti-rotation structures are disposed in the middle of the wall of the hollow tube; the plurality of anti-stretching structures and the plurality of anti-rotation structures are arranged alternately along the circumferential direction on the outer surface of the wall of the hollow tube.

[0019] Furthermore, the threaded core puller is provided with an exhaust position; the slider is provided with an exhaust position.

[0020] Furthermore, the manufacturing method of the transmission mechanism of the electronically controlled actuator also includes: fitting the transmission nut inside the rotor core; and performing secondary injection molding on the transmission nut and the rotor core fitted together to obtain the transmission mechanism.

[0021] Compared with existing technologies, this invention separates the injection molding of the nut and the rotor housing. First, the nut is injection molded (or separately) inside the rotor hollow tube. Then, the injection-molded transmission nut is pressed onto the rotor silicon steel sheet (or rotor core), and finally, a second injection molding is performed. Separate injection molding of the nut simplifies the mold structure, reduces cost, and facilitates mass production. Simultaneously, the simplified structure allows for optimization of the mold structure, making it easier to ensure the dimensional accuracy of the nut, thereby improving the transmission accuracy of the lead screw nut. [Attached Image Description]

[0022] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort. Wherein:

[0023] Figure 1 This is a flowchart illustrating a method for manufacturing the transmission mechanism of an electronically controlled actuator according to one embodiment of the present invention.

[0024] Figure 2 This is a perspective view of a hollow tube in one embodiment of the present invention;

[0025] Figure 3This is a perspective view of the transmission nut mold in one embodiment of the present invention;

[0026] Figure 4 This is a perspective view of the transmission nut in one embodiment of the present invention;

[0027] Figure 5 This is a longitudinal cross-sectional schematic diagram of the transmission nut in one embodiment of the present invention;

[0028] Figure 6 This is a longitudinal cross-sectional schematic diagram of the transmission mechanism of the electronically controlled actuator in one embodiment of the present invention.

Detailed Implementation Methods

[0029] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0030] The term "an embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that excludes other embodiments. Unless otherwise specified, the terms "connected," "linked," and "connected" used herein to indicate electrical connection refer to direct or indirect electrical connection.

[0031] Please refer to Figure 1 The diagram shown is a flowchart illustrating a method for manufacturing the transmission mechanism of an electronically controlled actuator according to one embodiment of the present invention. Please refer to [link / reference]. Figure 2 The image shown is a perspective view of a hollow tube according to one embodiment of the present invention. Please refer to... Figure 3 The image shown is a perspective view of a transmission nut mold according to one embodiment of the present invention. Please refer to... Figure 4 The image shown is a perspective view of the transmission nut in one embodiment of the present invention. Please refer to... Figure 5 The diagram shown is a longitudinal cross-sectional view of the transmission nut in one embodiment of the present invention. Please refer to... Figure 6 As shown, it is a longitudinal cross-sectional schematic diagram of the transmission mechanism of the electronically controlled actuator in one embodiment of the present invention.

[0032] Figure 1 The manufacturing method of the transmission mechanism of the electronically controlled actuator shown includes the following steps.

[0033] Step 110, as follows Figure 2 As shown, a hollow tube 1 is provided. The tube wall of the hollow tube 1 has a plurality of glue-passing holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6 arranged sequentially and at intervals along its axial direction. These glue-passing holes are cut using a CNC machine tool or laser equipment. Figure 2In the illustrated embodiment, the glue passage holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6 have different specifications.

[0034] Step 120, as follows Figure 5 As shown, a threaded core puller 2-4 and a slider 2-3 are provided. The threaded core puller 2-4 and the slider 2-3 are arranged sequentially in the hollow tube 1 along the axial direction of the hollow tube 1 to form a first cavity (i.e. the area where the injection nut 2 is located) surrounding the side wall of the threaded core puller 2-4 and the side wall of the slider 2-3 in the hollow tube 1.

[0035] Step 130, as Figure 3 As shown, an annular mold 4 is provided, which is sleeved on the outside of the hollow tube 1 to form a second cavity (not labeled) surrounding the hollow tube 1 between the annular mold 4 and the tube wall of the hollow tube 1, and the first cavity and the second cavity are connected through a glue-through hole. Figure 4 In the specific embodiment shown, the annular mold 4 is fitted in the middle of the hollow tube 1; the first cavity and the second cavity are connected through the glue passage hole 1-3; the annular mold 4 is provided with a glue inlet 4-1, preferably, the glue inlet 4-1 is a side gate.

[0036] Step 140: Inject the hollow tube 1 through the injection port 4-1 on the annular mold 4 to obtain the transmission nut, as detailed below. Figure 4 and Figure 5 As shown. After one injection molding, the plastic material can fuse with the hollow tube 1. That is, after one injection molding, the plastic material can fill several through holes 1-1, 1-2, 1-3, 1-4, 1-5, 1-6, the first cavity and the second cavity, so as to form the injection nut 2, several limiting structures 2-5, several anti-stretching structures 2-1 and several anti-rotation structures 2-2 in one injection molding.

[0037] Step 150, as follows Figure 6 As shown, the transmission nut is fitted inside the rotor core 5;

[0038] Step 160, as follows Figure 6 As shown, the transmission nut and rotor core 5, which are sleeved together, undergo secondary injection molding. During the secondary injection molding, the plastic material is injected through point 3-1, filling the entire rotor and simultaneously combining with the hollow tube 1 and injection nut 2 after the first injection molding, thus forming a secondary encapsulation (or secondary injection molding structure) 3.

[0039] exist Figure 4 and Figure 5 In the embodiment shown, the transmission nut includes a hollow tube 1 formed by one-time injection molding, an injection nut 2, several limiting structures 2-5, several anti-stretching structures 2-1, and several anti-rotation structures 2-2.

[0040] The injection nut 2 is formed from plastic material injected into the first cavity and can be used to mount the lead screw. Several limiting structures 2-5 are formed from plastic material injected into several through holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6. These limiting structures 2-5 can limit movement in both the axial and radial directions, ensuring the reliability of the axial and radial connection of the injection nut 2 under load and preventing the failure of force transmission if the injection nut 2 breaks off from the hollow tube 1 under stress.

[0041] Several anti-stretching structures 2-1 and several anti-rotation structures 2-2 are formed by plastic material injected into the second cavity. Figure 4 and Figure 5 In the specific embodiment shown, the anti-tension structure 2-1 is a boss; the anti-rotation structure 2-2 is a square anti-rotation structure; a plurality of anti-tension structures 2-1 and a plurality of anti-rotation structures 2-2 are arranged alternately along the circumferential direction on the outer surface of the hollow tube 1.

[0042] To prevent insufficient bonding force between the secondary overmolding 3 and the hollow tube 1 during secondary injection molding, an anti-stretch boss 2-1 is set in the middle section, and a four-sided anti-rotation structure 2-2 is set in the radial direction. This can increase the axial and radial loosening force during the secondary overmolding 3.

[0043] exist Figure 4 In the specific embodiment shown, the threaded core puller 2-4 is provided with an exhaust position; the slider 2-3 is provided with an exhaust position.

[0044] In this invention, the adhesive is injected from the middle of the hollow tube 1, and the adhesive is evenly distributed on both sides. At the same time, the threaded core puller 2-4 and the slider 2-3 are both provided with venting positions, which can make the internal threads of the injection nut 2 shrink evenly after injection molding, prevent the nut from deforming, and facilitate the control of the nut's precision.

[0045] According to another aspect of the present invention, the present invention provides a transmission mechanism for an electronically controlled actuator, based on Figures 2-6 As shown, the transmission mechanism of the electronically controlled actuator provided by the present invention includes a transmission nut (such as...). Figure 4 and Figure 5 (as shown), rotor core 5 and secondary injection molding structure 3.

[0046] Among them, the transmission nut (such as Figure 4 and Figure 5 (As shown) includes a hollow tube 1, an injection nut 2, several limiting structures 2-5, several anti-stretching structures 2-1 and several anti-rotation structures 2-2.

[0047] The hollow tube 1 has several glue-passing holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6 arranged sequentially and at intervals along its axial direction. These glue-passing holes are cut using a CNC machine tool or laser equipment. Figure 2 In the illustrated embodiment, the glue passage holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6 have different specifications.

[0048] The injection nut 2 is disposed inside the hollow tube 1. Several limiting structures 2-5 are respectively filled in several glue passage holes 1-1, 1-2, 1-3, 1-4, 1-5, and 1-6; several anti-stretching structures 2-1 are disposed on the outer surface of the tube wall of the hollow tube 1; several anti-rotation structures 2-2 are disposed on the outer surface of the tube wall of the hollow tube 1; wherein, the several limiting structures 2-5, the several anti-stretching structures 2-1, the several anti-rotation structures 2-2 and the injection nut 2 are integral structures formed by injection molding in one step inside the hollow tube 1.

[0049] The injection nut 2 is used to mount the lead screw; several limiting structures 2-5 can limit the movement in the axial and radial directions, which can ensure the reliability of the axial and radial connection of the injection nut 2 when it is under load, and can prevent the injection nut 2 from breaking with the hollow tube 1 when under force and thus failing to transmit force.

[0050] Figure 4 and Figure 5 In the embodiment shown, the anti-tension structure 2-1 is a boss; the anti-rotation structure 2-2 is a square anti-rotation structure; a plurality of anti-tension structures 2-1 and a plurality of anti-rotation structures 2-2 are located in the middle of the tube wall of the hollow tube 1; a plurality of anti-tension structures 2-1 and a plurality of anti-rotation structures 2-2 are arranged alternately along the circumferential direction on the outer surface of the tube wall of the hollow tube 1.

[0051] To prevent insufficient bonding force between the secondary overmolding (or secondary injection molding structure) 3 and the hollow tube 1 during secondary injection molding, an anti-stretching boss 2-1 is set in the middle section of the hollow tube 1, and a four-sided anti-rotation structure 2-2 is set in the radial direction to increase the axial and radial loosening force during secondary overmolding (or secondary injection molding structure) 3.

[0052] exist Figure 6 In the illustrated embodiment, the transmission nut is fitted inside the rotor core 5; the transmission nut and rotor core 5, fitted together, are subjected to secondary injection molding. This secondary injection molding involves injecting plastic at point 3-1, filling the entire rotor with plastic, and simultaneously combining it with the hollow tube 1 and injection nut 2 after the first injection molding, thus forming a secondary encapsulation (or secondary injection molding structure) 3. Alternatively, the secondary injection molding structure 3 can be described as injection molding the fitted transmission nut and rotor core 5 together.

[0053] In summary, this invention separates the injection molding of the nut and the rotor housing. First, the nut is injection molded (or separately) inside the rotor hollow tube in one step. Then, the injection-molded transmission nut is pressed onto the rotor silicon steel sheet (or inside the rotor core), and finally, a second injection molding is performed. This invention simplifies the mold structure and facilitates design and manufacturing by injection molding (or separately) the nut inside the rotor hollow tube in one step. Furthermore, the simple mold structure allows for a more rational design of the injection gate position and the arrangement of venting positions, thereby enabling better control of injection molding quality. This significantly improves the surface quality of the nut and controls warping deformation of the nut threads, thus reducing friction in the screw nut and better controlling tooth backlash.

[0054] Furthermore, in order to prevent the bonding force during secondary injection molding and secondary overmolding, an axial anti-tension boss 2-1 is designed in the middle section of the hollow tube 1, and a radial four-way anti-rotation structure 2-2 is designed at the same time, thereby increasing the axial and radial loosening force during secondary overmolding 3 and preventing axial and radial loosening.

[0055] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", and "outer" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0056] It should be noted that any modifications made by those skilled in the art to the specific embodiments of the present invention do not depart from the scope of the claims. Accordingly, the scope of the claims is not limited to the foregoing specific embodiments.

Claims

1. A transmission mechanism for an electrically controlled actuator, characterized by comprising: It comprises a transmission nut, the transmission nut comprises: A hollow tube, a plurality of glue holes are arranged on the tube wall of the hollow tube in a spaced manner; An injection nut arranged in the hollow tube; A plurality of limiting structures, respectively filled in the plurality of glue holes, Wherein, the plurality of limiting structures and the injection nut are an integral structure formed by one-time injection in the hollow tube, The transmission nut further comprises: A plurality of anti-stretching structures arranged on the outer surface of the tube wall of the hollow tube; A plurality of anti-rotation structures arranged on the outer surface of the tube wall of the hollow tube; Wherein, the plurality of limiting structures, the plurality of anti-stretching structures, the plurality of anti-rotation structures and the injection nut are an integral structure formed by one-time injection in the hollow tube, and the anti-rotation structure is a square anti-rotation structure, It also includes: Rotor core, wherein the transmission nut is sleeved in the rotor core; The transmission nut and the rotor core sleeved together are injection molded together to obtain a transmission mechanism.

2. The transmission mechanism of the electric control actuator according to claim 1, wherein The plurality of anti-stretching structures and the plurality of anti-rotation structures are located in the middle part of the tube wall of the hollow tube; The plurality of anti-stretching structures and the plurality of anti-rotation structures are arranged in a circumferential direction on the outer surface of the tube wall of the hollow tube.

3. A method of manufacturing a transmission mechanism of an electrically controlled actuator, characterized by, It comprises: Providing a hollow tube, a plurality of glue holes are arranged on the tube wall of the hollow tube in a spaced manner; Providing a threaded core and a slider, the threaded core and the slider are arranged in the hollow tube in a sequential manner along the axial direction of the hollow tube to form a first cavity around the side wall of the threaded core and the side wall of the slider in the hollow tube; Providing an annular mold, the annular mold is sleeved outside the tube body of the hollow tube to form a second cavity around the hollow tube between the annular mold and the tube wall of the hollow tube, and the first cavity and the second cavity are communicated through the glue holes; By one-time injection into the hollow tube and the annular mold to obtain a transmission nut, The transmission nut comprises the hollow tube, the injection nut, the plurality of limiting structures, the plurality of anti-stretching structures and the plurality of anti-rotation structures, The injection nut is formed by plastic material injected into the first cavity; The plurality of limiting structures are formed by plastic material injected into the plurality of glue holes; The plurality of anti-stretching structures and the plurality of anti-rotation structures are formed by plastic material injected into the second cavity, It also includes: Sleeving the transmission nut in the rotor core; The transmission nut and the rotor core sleeved together are injection molded to obtain a transmission mechanism.

4. The manufacturing method of the transmission mechanism of the electric control actuator according to claim 3, wherein The annular mold is provided with a glue inlet; By one-time injection into the hollow tube and the annular mold through the glue inlet on the annular mold to obtain a transmission nut.

5. The manufacturing method of the transmission mechanism of the electric control actuator according to claim 4, wherein The anti-stretching structure is a boss; The anti-rotation structure is a square anti-rotation structure.

6. The manufacturing method of the transmission mechanism of the electric control actuator according to claim 4, wherein The stretch-preventing structures and the rotation-preventing structures are arranged in the middle of the wall of the hollow pipe. The stretch-preventing structures and the rotation-preventing structures are arranged in the middle of the wall of the hollow pipe.

7. The manufacturing method of the transmission mechanism of the electric control actuator according to claim 3, wherein An exhaust position is arranged on the threaded core. An exhaust position is arranged on the slider.

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