The application discloses a mounting structure of a PCB control board of a micro electronic oil pump and the electronic oil pump

Abstract

An installation structure for a PCB control board of a miniature electronic oil pump is disclosed. The pump body has a pump function unit built into the upper section along the pump axis, and the lower section extends along the pump axis as a cylindrical body with an open bottom end. The opening is closed by a bottom cover through its flange, forming a control cavity for accommodating the PCB control board assembly. A first connecting terminal is inserted into a terminal block, limiting its socket contact portion and exposing its first pin portion. A small positioning pin protrudes from the exposed end of the terminal block at the first pin portion and is inserted into a small positioning hole on the PCB for accurate alignment. A first positioning post extends from the pump body toward the opening, inserts into a first through hole penetrating the PCB and then into a guide blind hole inside the bottom cover, reducing the impact of cumulative manufacturing errors of the three components. A second pin is embedded through the bottom cover, with the inner pin end of the second pin exposed inside the bottom cover. It is inserted into the socket contact portion, ensuring accurate alignment and preventing poor contact due to offset or deformation / displacement of the socket contact portion, thus avoiding burning of the socket contact portion.

Description

Technical Field

[0001] This utility model relates to a miniature electronic oil pump, and more particularly to the mounting structure of the PCB control board of the electronic oil pump, which can be classified as F04C14 / 00 by IPC. Background Technology

[0002] The existing internal meshing cycloidal gear pump (referred to as rotor pump) is a typical internal combustion engine oil pump (referred to as oil pump) in JB / T 8413. Its gears usually use powder metallurgy inner and outer rotors (referred to as inner and outer rotors). On this basis, its drive mechanism is changed to micro motor drive and an electronic control unit is introduced to adjust the oil volume and pressure of the pump, evolving into a new type of controllable oil pump (referred to as electronic oil pump). It can not only adjust the oil volume and pressure of the pump in real time according to the engine operating conditions (such as speed, temperature, load), but also be widely used in electric vehicle electric drive and battery thermal management cooling systems, braking and steering lubrication systems and other situations with high control and adjustment requirements. This electronic oil pump incorporates a micro-motor and an electronic control unit. A motor is located in the middle section of the pump housing, directly driving the inner and outer rotors of the pump mechanism located at one end of the pump housing. An electronic control unit is located at the other end of the pump housing. For example, the electronic oil pump described in Chinese patent CN222415219U forms a cavity (i.e., a control cavity) at the bottom of the pump housing to house the PCB control board. This cavity is covered with a bottom cover and secured with screws, while a sealing ring is used to seal the cover. However, sealing rings are mostly used to seal dry control cavities, and installing the sealing ring requires high-precision machining of the sealing groove, increasing processing difficulty and cost. Secondly, the cavity housing the PCB control board is a wet control cavity immersed in working oil. Even during normal operation, it must meet the harsh conditions of high temperature (150℃) and low temperature (-40℃) and be oil-resistant. Ordinary sealing rings are prone to aging. If oil-resistant materials with good high and low temperature performance are used, the cost increases significantly, and the production process is demanding, which is not conducive to mass production. On the other hand, existing technologies, such as the electronic oil pump described in Chinese patent CN222457752U, are limited by the small space for accommodating the PCB control board. The diameter of the PCB board cannot exceed 10cm. In order to retain more board area, the PCB board, the bottom cover, and the pump body are only indirectly positioned without direct limiting. In addition, the female connector is directly soldered to the PCB board without the use of plastic insulating base for installation constraint. As a result, the corresponding pins on the bottom cover generally adopt the blind-plug female connector electrical connection method, which is prone to poor contact failure and burn-out.

[0003] Common knowledge and related terms can be found in Chinese patents CN222415219U and CN222457752U, as well as JB / T8413 "Internal Combustion Engine Oil Pump", JB / T 14395 "Technical Specification for Powder Metallurgy Inner and Outer Rotors for Automobile Oil Pumps", QC / T 289 "Automobile Engine Oil Pump", GB / T 33925.1 "General Terms, Definitions, Quantities, Characters and Units for Liquid Pumps and Their Devices - Part 1: Liquid Pumps", GB / T 7021 "Centrifugal Pump Terminology", JB / T5415 "Miniature Centrifugal Electric Pump", "IEC Electrical and Electronic Standards Terminology Dictionary" (China Standards Press, 1st edition, 1992), "Electrical Manufacturing Technology" (Mechanical Industry Press, 1st edition, 1982), "Mechanical Engineering Handbook", and "Electrical Engineering Handbook" (Mechanical Industry Press, 1st edition, 1978 and 2nd edition, 1997). Utility Model Content

[0004] This invention aims to at least solve one of the aforementioned technical problems existing in the prior art. To this end, this invention proposes a miniature electronic oil pump with an improved mounting structure for its PCB control board.

[0005] The technical solution of this utility model is:

[0006] A mounting structure for a PCB control board of a miniature electronic oil pump is disclosed. The pump body has a built-in pump functional unit in the upper section along the pump axis, and the lower section extends along the pump axis as a cylindrical body with an open bottom end. This opening is closed by a bottom cover through its flange, forming a control cavity for accommodating the PCB control board assembly.

[0007] The first connecting terminal includes a first pin portion and a socket contact portion. The first connecting terminal is inserted into a terminal block and is limited such that its socket contact portion is constrained within the terminal block, while its first pin portion is exposed outward.

[0008] The terminal block has at least two small positioning pins protruding from the exposed end of the first pin portion. The small positioning pins are inserted into at least two corresponding small positioning holes on the PCB board. The first pin portion is soldered to the PCB board, thereby assembling the PCB control board assembly.

[0009] The pump body extends a first positioning post along the pump axis from deep within the control cavity toward the opening. The PCB board has a first through hole corresponding to the first positioning post, and the bottom cover has a corresponding guide blind hole on the inner side facing the control cavity.

[0010] During assembly, the first positioning post is inserted into and passes through the first through hole and then into the guide blind hole to install and fix the PCB control board assembly in the control cavity. The first positioning post is used as a common reference to achieve axial alignment of the pump body, PCB board and bottom cover.

[0011] A second pin is embedded through the bottom cover. The second pin has an outer pin end that protrudes from the outside of the bottom cover and an inner pin end that protrudes from the inside of the bottom cover along the pump axis.

[0012] The inner pin end is inserted into the socket contact portion within the terminal block to form an electrical connection.

[0013] The first positioning post on the pump body passes through the first through hole on the PCB board and is accurately aligned with the guide blind hole on the bottom cover. Compared with the existing technology where the PCB board is fixed to the pump body first and lacks direct alignment with the bottom cover, this reduces the cumulative error of the three components during manufacturing. The two small positioning pins on the terminal block are inserted into the corresponding two small positioning holes on the PCB board for accurate alignment. Compared with snap-fit ​​or direct welding limit, the positioning accuracy is high. At the same time, the terminal block blocks and limits the insertion hole contact part, ensuring that the inner pin end on the pump cover can be accurately inserted into the insertion hole contact part in the terminal block when blindly inserted. It will not cause poor contact due to the misalignment of the two or the deformation or displacement of the insertion hole contact part, thereby avoiding the burning of the insertion hole contact part.

[0014] The typical design of this technical solution is as follows: the maximum external dimension D of the PCB board does not exceed 10cm, the number of the first positioning post, the first through hole, and the guide blind hole is one each, and the distance S between the center of the first through hole and the terminal block does not exceed 4cm, the number of the first connecting terminals is not less than two, the number of the second pins is not less than two, the first through hole is a round hole with an inner diameter not exceeding 3mm, and the small positioning hole is a round hole with an inner diameter not exceeding 1.5mm.

[0015] With the PCB board fixed to the pump body, by controlling the distance S between the center of the first through hole and the terminal block to not exceed 4cm, only one first positioning post is used to achieve precise alignment of the pump body, PCB board, and bottom cover, thereby saving the board layout space of the small area PCB board; the first through hole is a round hole, and the positioning post and positioning pin are cylindrical, which has high positioning accuracy and is easy to manufacture. At the same time, the positioning hole with a small inner diameter is used to further save the board layout space of the small area PCB board.

[0016] Furthermore, the pump body cylinder opening has an annular groove on its end face, and the flange portion of the bottom cover facing the end face has an annular rib corresponding to the position of the annular groove. The flange portion also has a convex stop, which forms an annular boss. The annular boss is inserted into and fits against the inner circumferential wall of the cylinder. The annular boss extends along the pump axis with an inwardly inclined guide platform. The guide platform is used to guide the annular boss to smoothly insert into and fit against the inner circumferential wall of the cylinder during assembly. The annular boss and the inner circumferential wall of the cylinder form a circumferential welding area by ultrasonic welding. The annular rib and the annular groove form the most suitable annular end face welding area for ultrasonic welding. Compared with vibration welding and rotary friction welding, there is no significant vibration or displacement perpendicular to the axial direction, which makes it easier for the first positioning post on the pump body to be aligned with the guide blind hole of the bottom cover after penetrating the PCB board. The inwardly inclined guide platform extending axially from the annular boss can smoothly guide the inner circumferential wall of the cylinder with opening deformation, improving production efficiency and reducing defect rate.

[0017] The more specific design and technical effects of this utility model are further explained in conjunction with the accompanying drawings in the specific embodiments. Attached Figure Description

[0018] Figure 1 This is an axial sectional view of the electronic oil pump of this utility model;

[0019] Figure 2 yes Figure 1 A magnified view of a portion of region A in the middle;

[0020] Figure 3 yes Figure 1 A magnified view of a portion of region B in the middle;

[0021] Figure 4 This is a schematic axial cross-sectional view of the electronic oil pump of this utility model along another cutting plane;

[0022] Figure 5 This is an exploded view of the pump body, PCB control board assembly, and bottom cover;

[0023] Figure 6 This is an exploded view of the pump body, PCB control board assembly, and bottom cover from another angle;

[0024] Figure 7 This is a three-dimensional partial cross-sectional view of the pump body, PCB control board assembly, and bottom cover assembly.

[0025] Figure 8 This is a bottom view of the PCB control board assembly;

[0026] Figure 9 yes Figure 8 CC section view in the image.

[0027] Figure label:

[0028] Pump body 100, cylinder 110, control chamber 111, first positioning post 112, annular groove 113;

[0029] PCB control board assembly 200, PCB board 210, first through hole 211, small positioning hole 212, first connecting terminal 220, first pin part 221, socket contact part 222, terminal block 230, small positioning pin 231;

[0030] Bottom cover 300, annular rib 301, annular boss 302, guide platform 303, guide post 304, guide blind hole 305, receiving groove 306, flange part 307, second pin 310, inner pin end 311, outer pin end 312, connecting section 313;

[0031] Circumferential welding area 10, circumferential end welding area 20;

[0032] Stator 400, motor rotor 500, pump internal rotor 600, pump external rotor 700. Detailed Implementation

[0033] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only a part of the embodiments of the present utility model, and not all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the protection scope of the present utility model.

[0034] The terms "center," "top or above," and "bottom or below" used in the text are based on Figure 1 The indicated orientation or positional relationship Figure 1 The centerline is the central axis of the pump body (i.e., the pump and motor axis), and the orientation of "top or above" and "bottom or below" can be interchanged.

[0035] like Figure 1-4As shown, the electronic oil pump of this utility model adopts a typical internal meshing cycloidal gear pump assembly. The electronic oil pump includes a pump body 100, a PCB control board assembly 200, and a bottom cover 300. A motor section consisting of a stator 400 and a motor rotor 500 is installed in the middle section of the pump body 100. Along the motor axis, a gear pump functional section consisting of an internal pump rotor 600 and an external pump rotor 700 is built into the upper section of the pump body 100. The lower section of the pump body 100 extends into a cylindrical body 110 with an open bottom end. This cylindrical body 110 can be cylindrical, elliptical, square, or other shapes suitable for industrial production. The cylindrical body 110 forms an opening towards the bottom. The cavity has a first circular positioning post 112 and several connecting terminals extending axially from the stator portion deep within the cavity toward the opening. The end face of the opening of the cylinder 110 is provided with an annular groove 113. The PCB control board assembly 200 is installed and fixed in the cavity and electrically connected to the stator through several connecting terminals to control the pump motor. The end face of the opening of the cylinder 110 is covered by a flange portion 307 on the bottom cover 300, forming a control cavity 111 that accommodates the PCB control board assembly 200, which includes the aforementioned cavity. The flange portion 307 of the bottom cover 300 is also provided with a protruding stop that inserts into the opening of the cylinder 110.

[0036] like Figure 3 , Figure 5-9 As shown, the PCB control board assembly 200 includes a PCB board 210, a terminal block 230, and three first connection terminals 220. Each first connection terminal 220 has a first pin portion 221 and a socket contact portion 222. The three first connection terminals 220 are inserted into the terminal block 230 and are limited, so that their socket contact portions 222 are constrained within the terminal block 230, while their first pin portions 221 protrude outward. The terminal block 230 has two small positioning pins 231 protruding from the exposed end of the first pin portion 221. The PCB board 210 has a first through hole 211 corresponding to the first positioning post 112 and two small positioning holes 212 corresponding to the two small positioning pins 231. The two small positioning pins 231 of the terminal block 230 are inserted into the two small positioning holes 212 of the PCB board 210, and the first pin portion 221 is soldered onto the PCB board 210, thereby assembling the PCB control board assembly 200.

[0037] like Figure 2-4As shown, the flange portion 307 of the bottom cover 300 is provided with an annular rib 301 that is inserted into the annular groove 113. The flange portion 307 has a convex stop forming an annular boss 302. The annular boss 302 extends along the pump axis with an inwardly inclined guide platform 303. The guide platform 303 can also be intermittently set into several segments along the circumferential direction on the continuous annular ring of the annular boss 302. The bottom cover 300 is provided with a guide post 304. The guide post 304 is hollow inward to form an axial guide blind hole 305 corresponding to the first positioning post 112. Three second pins 310 are embedded through the bottom cover 300. Each second pin 310 has an inner pin end 311 for internal electrical connection and an outer pin end 312 for external electrical connection, as well as a connecting section 313 between the two. The inner pin end 311 and the outer pin end 312 are connected by the connecting section 313. 3. The connection is offset, and the offset L2 is (5 to 10) times the thickness t of the second pin 310. The inner pin end 311 is partially exposed on the inner side of the bottom cover 300 along the pump axis, and the outer pin end 312 is partially exposed on the outer side of the bottom cover 300 along the pump axis. The connecting section 313 is embedded in the material of the bottom cover 300. The bottom cover 300, annular rib 301, annular boss 302, guide platform 303, guide post 304 and guide blind hole 305 are integrally formed by injection molding with the second pin 310 as the insert. A receiving groove 306 is formed around the inner pin end 311. The receiving groove 306 is filled with sealant (not shown). The insert injection molding here can also first use the second pin 310 as the insert to injection mold a plastic seat with the second pin 310, and then use the plastic seat as the insert to injection mold the bottom cover 300 and the above-mentioned auxiliary structures.

[0038] like Figure 1-9 As shown, during the specific installation of the pump body 100, PCB control board assembly 200, and bottom cover 300, the first positioning post 112 on the pump body 100 is first inserted into and passes through the first through hole 211 of the PCB control board assembly 200. Then, the PCB board 210 is welded perpendicular to the pump axis and to several connecting terminals on the pump body 100 and fixed in the control cavity 111. Then, the first positioning post 112 is inserted into the guide blind hole 305 of the bottom cover 300, and the guide platform 303 guides the annular boss 302 to be inserted into the inner peripheral wall of the cylinder 110 and fits with it, thereby guiding the inner needle end 311 of the bottom cover 300 to be inserted into the insertion hole contact part 222 in the terminal seat 230 to form an electrical connection. The annular boss 302 and the inner peripheral wall of the cylinder 110 are welded to form an annular surface welding area 10. The annular rib 301 of the bottom cover and the annular groove 113 of the cylinder are matched and welded to form an annular end face welding area 20. Ultrasonic welding is preferred.

[0039] The annular rib 301 and annular groove 113 form an annular end face welding area 20 at the end face of the opening of the cylinder 110 and the flange portion 307 of the bottom cover 300. The convex stop of the bottom cover 300 is inserted into the inner peripheral wall of the cylinder 110 in the form of an annular boss 302 to form an annular surface welding area 10. This fully utilizes the welding in both directions of the thin wall end face and the inner peripheral surface of the cylinder 110 to achieve double sealing, improve sealing performance, and save materials. The guide platform 303, which extends axially and tilts inward through the annular boss 302, can smoothly guide the cylinder 110 inner peripheral wall that is deformed at the opening, thereby improving production efficiency and reducing defect rate. The axial length L0 of the annular boss 302 is not less than 1.5mm, and the axial length L1 of the annular surface welding area 10 is not less than 1.5mm. When the pump cylinder 110 has a thin wall, it can increase the welding contact area and improve the sealing effect. The axial length L1 of the annular surface welding area 10 is preferably 1.7-4.0mm, which has good manufacturability and excellent sealing effect. The annular groove and annular rib that are paired and welded here can also be set on the flange of the bottom cover and the end face of the cylinder opening, respectively.

[0040] The offset L2 between the inner and outer ends of the second pin 310 embedded in the bottom cover 300 is (5 to 10) times the thickness t of the pin. This increases the plastic seal contact length, extends the liquid leakage path from the inside to the outside along the pin, and enhances the sealing performance. The bottom cover 300 forms a receiving groove 306 around the exposed part of the inner pin end 311 and fills it with sealant to further enhance the sealing performance of the pin.

[0041] The first positioning post 112 on the pump body 100 passes through the first through hole 211 on the PCB board 210 and is accurately aligned with the guide blind hole 305 on the bottom cover 300. Using the first positioning post as a common reference, the axial alignment of the pump body 100, PCB board 210 and bottom cover 300 is achieved. Compared with the prior art, where the PCB board is fixed to the pump body first and lacks direct alignment with the bottom cover, this reduces the cumulative error in manufacturing. The two small positioning pins 231 on the terminal block 230 are inserted into the corresponding two small positioning holes 212 on the PCB board 210 for accurate alignment. Compared with snap-fit ​​or direct welding limit, the positioning accuracy is high. At the same time, the terminal block 230 blocks and limits the insertion hole contact part 222, ensuring that the inner pin end 311 on the bottom cover 300 can be accurately inserted into the insertion hole contact part 222 in the terminal block 230 in the case of blind insertion. It will not cause poor contact due to the offset of the two or the deformation or displacement of the insertion hole contact part, thereby avoiding the burning of the insertion hole contact part.

[0042] For a small-area PCB board 210 with a maximum external dimension D not exceeding 10cm, the distance S between the center of the first through hole 211 on the PCB board and the terminal block 230 is set to not exceed 4cm, and preferably to be close to each other by no more than 1cm. With the PCB board 210 fixed to the pump body 100, only one first positioning pin 112 is used to achieve accurate alignment of the pump body 100, PCB board 210, and bottom cover 300, thus saving space on the small-area PCB board. To further save space, the first through hole 211 on the PCB board 210 is set as a circular hole with an inner diameter not exceeding 3mm, and the small positioning hole 212 is set as a circular hole with an inner diameter not exceeding 1.5mm. The first positioning pin 112 and the small positioning pin 231 are both cylindrical, providing high positioning accuracy and ease of manufacturing.

[0043] In the above embodiments, the number of the first connecting terminal 220 inserted into the terminal block 230 and the number of the second pin 310 embedded through the bottom cover 300 are both 3. In other embodiments, the corresponding number can also be 1, 2 or more, and the above technical solution can be applied in the same way.

[0044] The pump functional unit, consisting of an internal rotor and an external rotor, is an internal meshing cycloidal gear pump. The pump functional unit can also be replaced by another typical external meshing involute gear pump, such as an oil pump. Alternatively, the pump functional unit can be replaced by a centrifugal pump with an impeller rotating inside the pump casing, used as an electronic water pump in the power thermal management system of electric vehicles.

[0045] It is understood that the present invention has been described through some embodiments, and those skilled in the art will recognize that various changes or equivalent substitutions can be made to these features and embodiments without departing from the spirit and scope of the invention. Furthermore, under the teachings of the present invention, these features and embodiments can be modified to adapt to specific situations and materials without departing from the spirit and scope of the invention. Therefore, the present invention is not limited to the specific embodiments disclosed herein, and all embodiments falling within the scope of the claims of this application are within the protection scope of the present invention.

Claims

1. A mounting structure for a PCB control board of a miniature electronic oil pump, wherein the pump body (100) has a pump function unit built into the upper section along the pump axis, and the lower section extends along the pump axis as a cylindrical body (110) with an open bottom end, the opening being covered by a bottom cover (300) through its flange (307), thus sealing a control cavity (111) for accommodating a PCB control board assembly (200), characterized in that: The first connecting terminal (220) includes a first pin portion (221) and a socket contact portion (222). The first connecting terminal (220) is inserted into a terminal block (230) and is limited such that its socket contact portion (222) is constrained within the terminal block (230), while its first pin portion (221) is exposed outward. The terminal block (230) has at least two small positioning pins (231) protruding from one end of the first pin portion (221). The small positioning pins (231) are inserted into at least two corresponding small positioning holes (212) on the PCB board (210). The first pin portion (221) is soldered to the PCB board (210) to assemble the PCB control board assembly (200). The pump body (100) extends a first positioning post (112) from the depth of the control cavity (111) toward the opening along the pump axis. The PCB board (210) is provided with a first through hole (211) corresponding to the first positioning post (112), and the bottom cover (300) is provided with a guide blind hole (305) on the inner side facing the control cavity (111). During assembly, the first positioning post (112) is inserted into and passes through the first through hole (211) and then inserted into the guide blind hole (305) to install and fix the PCB control board assembly (200) in the control cavity (111). With the first positioning post as a common reference, the axial alignment of the pump body (100), PCB board (210) and bottom cover (300) is achieved. The bottom cover (300) is provided with a second pin (310) which has an outer pin end (312) exposed on the outside of the bottom cover (300) for external electrical connection and an inner pin end (311) exposed on the inside of the bottom cover (300) along the pump axis. The inner pin end (311) is inserted into the socket contact portion (222) within the terminal block (230) to form an electrical connection.

2. The installation structure according to claim 1, characterized in that: The maximum external dimensions of the PCB board (210) do not exceed 10cm. The number of the first positioning post (112), the first through hole (211), and the guide blind hole (305) are all one, and the distance S between the center of the first through hole (211) and the terminal block (230) does not exceed 4cm.

3. The installation structure according to claim 2, characterized in that: The number of the first connection terminal (220) is not less than 2, and the number of the second pin (310) is not less than 2.

4. The installation structure according to claim 3, characterized in that: The first through hole (211) is a round hole with an inner diameter not exceeding 3 mm; the small positioning hole (212) is a round hole with an inner diameter not exceeding 1.5 mm.

5. The mounting structure according to any one of claims 1-4, characterized in that: The end face of the opening of the cylinder (110) is provided with an annular groove (113), and the flange part (307) of the bottom cover (300) is provided with an annular rib (301) corresponding to the position of the annular groove (113); The flange (307) also has a raised stop, which is configured as an annular annular boss (302) that is inserted into and fits against the inner peripheral wall of the cylinder (110). The annular boss (302) and the inner circumferential wall of the cylinder (110) are ultrasonically welded to form an annular surface welding area (10); The annular rib (301) and the annular groove (113) are ultrasonically welded to form an annular end face welding area (20).

6. The installation structure according to claim 5, characterized in that: The annular boss (302) extends along the pump axis and has an inwardly inclined guide platform (303), which is used to guide the annular boss (302) to be smoothly inserted into the inner peripheral wall of the cylinder (110) during assembly.

7. The installation structure according to claim 5, characterized in that: The axial length L1 of the circumferential welding area (10) is 1.7-4.0 mm.

8. The mounting structure according to any one of claims 1-4, characterized in that: The outer needle end (312) that is partially exposed on the outside of the bottom cover (300) is partially exposed along the pump axis. The inner needle end (311) and the outer needle end (312) of the second needle (310) are connected by a connecting section (313) and offset. The offset L2 is 5-10 times the thickness t of the second needle (310). The bottom cover (300) is injection molded with the second needle (310) as an insert.

9. The installation structure according to claim 8, characterized in that: The bottom cover (300) is integrally injection molded around the inner needle end (311) to form a receiving groove (306), which is filled with sealant.

10. A miniature electronic oil pump, characterized in that: The mounting structure includes the PCB control board as described in any one of claims 1 to 9.

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