JP5713646B2 - Electric pump - Google Patents

Description

  The present invention relates to a configuration of a motor control circuit unit provided in an in-vehicle electric pump, and is particularly excellent in assembling of a circuit board and an electronic component, and has improved shock resistance. It relates to an electric pump.

  In recent years, the mounting of electric pumps (electric water pumps, etc.) on vehicles has increased due to the progress of electrification and hybridization of vehicles. Of the electric pumps, a so-called integrated electric pump in which a portion having a motor function and a portion having a pump function are integrated is often used. In the integrated electric pump, a stator composed of a stator core and a coil serving as a stator of a motor, an inner magnet serving as a rotor of the motor, and an impeller integrated with the inner magnet are arranged. .

  Since this type of electric pump is used as a water pump for cooling the engine, it is often mounted near the engine. Therefore, the electric pump directly applies vibrations from the engine and shocks generated during traveling of the automobile. It is what you receive. In an electric pump used under such conditions, vibrations and impacts are particularly applied to circuit boards and electronic components, and vibrations and impacts are also generated at electrical connection points for energizing these circuit boards and electronic components. Communicated.

  The use of shock-resistant circuit boards and electronic components solves the problem, but the connection between the electrical connection points is cut off and the circuit board and the electronic components are disconnected from each other. Sometimes. Therefore, in order to prevent such cutting, there is one in which a lead frame is inserted into a resin member constituting a casing. Patent document 1 is mentioned as what was equipped with such a structure.

JP 2002-237422 A

  In Patent Document 1, a lead frame joint 2 formed in a series on a lead frame 1 is projected from a primary molding resin 10 to perform primary insert molding, and a lead of an electronic component 3 is welded through the lead frame joint 2. Secondary insert molding including electronic component 3 is performed. Further, in Patent Document 1, a lead frame joint 2 is vertically projected from a flat primary insert molded product 4, and a lead 15 of an electronic component 3 is mounted on a concave portion of the lead frame joint 2 and mounted by laser. Melt 15 and weld.

  It can be seen that the lead frame joint 2 protrudes vertically from the flat primary insert molded product 4, and the electronic component 3 is welded to the side surface of the lead frame joint 2 protruding vertically. As a result, Patent Document 1 describes that it is possible to reduce the size, increase the productivity, and improve the quality such as mechanical strength while enabling use even at high temperatures.

  However, Patent Document 1 has the following problems. Since the lead frame joint 2 protrudes vertically from the flat primary insert molded product 4, and the electronic component 3 is welded to the side surface of the lead frame joint 2 protruding vertically, the flat primary insert molded product 4 However, since the electronic component 3 and the like are arranged at a high (separated) position, the dimensions are increased in the height direction. In addition, since it is necessary to bend and form the lead frame joints 2 corresponding to the number of leads 15 of the electronic component 3, the number of bent portions increases, so that the number of manufacturing processes increases and there is a limit to increasing productivity.

  Further, since the lead frame joint 2 protrudes vertically from the flat primary insert molded product 4, the lead frame joint 2 is cantilevered and the electronic component 3 is welded to the side surface of the lead frame joint 2. The electronic components also vibrate in response to intense external vibrations and shocks such as vibrations from the engine, and there is room for further improvement in the durability of the welded part. An object (technical problem) of the present invention is to provide an electric pump having a compact electrical connection portion between electronic components of a circuit board and excellent in assembly.

  Therefore, as a result of intensive studies to solve the above-mentioned problems, the inventor is able to connect the invention of claim 1 to the motor unit mounted on the pump unit and to have a base plate, and a circuit board. A motor control unit comprising a power device, wherein the pump unit, the motor unit, and the motor control unit are arranged in this order, and a lead frame is insert-molded on the base plate, and an outer surface of the base plate On the side, an exposed opening is formed at a proper position where a part of the lead frame is exposed in parallel with the plate surface of the base plate. On the outer surface side of the base plate, a terminal of the power device is provided via the exposed opening. Is fixedly welded, and a circuit board is disposed on a closed peripheral wall portion formed on the inner surface side of the base plate. The power device is controlled by the circuit board, and the front of the base plate is The exposed opening is formed on the inner surface side so as to be in the same position corresponding to the exposed opening formed on the outer surface side, and the circuit board is exposed to the exposed opening in the closed peripheral wall portion. The above-described problems have been solved by using an electric pump that is in contact with the lead frame so as to be energized.

  According to a second aspect of the present invention, the above-described problem is solved by using the electric pump according to the first aspect in which the exposed opening is formed in a hollow shape. According to a third aspect of the present invention, in the first aspect of the present invention, the above-described problem is solved by using an electric pump in which the exposed opening and the lead frame are flush with each other.

  According to the first aspect of the present invention, an exposed opening is formed in the base plate, which is inserted into the base plate of the resin circuit case, and a part of the lead frame is exposed, and the lead frame is exposed from the exposed opening. The part is made to be parallel to the base plate. As a result, when the circuit case is molded, the exposed opening is formed together with the molding of the circuit case only by molding so that the resin is not disposed at the exposed opening portion, and can be manufactured without requiring a dedicated process. .

  Therefore, the manufacturing cycle time and cost are not particularly increased. Since the electric element is disposed on the base plate of the circuit case, the lead frame is exposed so as to be parallel to the plate surface of the base plate, thereby facilitating welding of the terminals of the electric element. In addition, the exposed opening is formed as a slightly recessed surface, which eliminates the need to bend the lead frame substantially vertically in order to protrude outward from the circuit case, thereby reducing manufacturing cycle time and cost. be able to.

  In addition, since the lead frame does not protrude outward from the circuit case, the dimensions of the circuit portion in the height direction can be minimized by arranging the electric elements to lie down or lie down. Since the electric element is welded to the lead frame at the exposed opening portion, the electric element does not vibrate unnecessarily due to external vibration, and durability can be improved.

Is further mounted a circuit board on the inner surface side of the base plate, and a configuration in which a power device is mounted on the outer surface side, and the power device because the circuit board 3 and the power devices are connected by lead frame was inserted into the base plate The circuit board is separated from the base board. As a result, the heat transfer from the power device to the circuit board can be suppressed as much as possible through wiring by the lead frame, and the temperature of the circuit board can be kept low, so the reliability of the electrical elements mounted on the circuit board is improved. Therefore, even an inexpensive electric element having low heat resistance can be used for the circuit board, and the price of the entire motor control unit can be reduced.

  In the invention according to claim 1, the exposed openings formed on the inner surface side and the outer surface side of the base plate in the circuit case of the motor control unit are formed at the same position so as to correspond to each other. By using the pump, the configuration is extremely suitable for connecting electronic components such as power devices to the lead frame by resistance welding on the inner surface side and outer surface side of the base plate. In resistance welding, an electrode is pressed against both surfaces of a place to be welded, and a large current is applied and a load is applied in a state where a load is applied. The lead frame inserted into the base plate is exposed to the same corresponding positions on both the inner surface side and the outer surface side of the base plate through the exposed opening, so that electrodes are provided on both surfaces of the lead frame. It can be pressed, and is a very suitable configuration for resistance welding.

In the invention of claim 2, since the exposed opening is formed in a depression shape, when the terminal of the power device is welded and fixed to the lead frame, the molten metal is accommodated in the exposed opening, and the weld fixing is excellent in finish. Can be. In the invention of claim 3, since the exposed opening and the lead frame are formed in the same plane, the terminal of the power device can be easily installed, so that the operation can be facilitated.

(A) is a vertical side view of the electric pump of the present invention, (B) is an enlarged vertical side view of the motor control unit. (A) is a vertical side view of the circuit case, (B) is a view as seen from the inner surface side of the circuit case, and (C) is a view as seen from the outer surface side of the circuit case. (A) is the perspective view seen from the inner surface side of a circuit board, (B) is the (A) part enlarged view of (A), (C) is XX arrow sectional drawing of (B), (D) is It is a modification of (C), and is an enlarged vertical side view in which the exposed opening on the outer surface side and the lead frame are substantially in the same plane. (A) is a plan view showing the arrangement of the lead frame, (B) is a perspective view showing the shape of the lead frame, and (C) shows a state in which the lead frame and the terminals of the power device are resistance-welded through the exposed openings. It is an enlarged view. (A) is the top view seen from the outer surface side which shows the mounting state of the power device in a circuit case, (B) is the (A) part enlarged view of (A), (C) is Ya-Ya arrow view of (B). Sectional drawing and (D) are Yb-Yb arrow sectional views of (C).

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1A, the configuration of the electric pump according to the present invention includes a motor control unit A, a motor unit B, and a pump unit 9. As shown in FIG. 1B, the motor control unit A includes a circuit case 1, a lead frame 2, a circuit board 3, and a power device 4 such as an FET. The circuit case 1 is formed of a synthetic resin, and a cylindrical outer peripheral side portion 12 protruding from both side surfaces is formed on the outer periphery of a substantially disc-shaped base plate 11.

  As shown in FIG. 2, the base plate 11 has an inner surface side 1a and an outer surface side 1b. The inner surface side 1a is a side connected to the motor housing 1, and the circuit board 3 is mounted thereon. . Moreover, the closed peripheral wall part 13 mentioned later is formed in the inner surface side 1a [refer FIG. 2 (A), (B)]. A power device 4 is incorporated in the outer surface side 1b. A lead frame 2 is insert-molded on the base plate 11 of the circuit case 1 as shown in FIGS.

  As shown in FIGS. 4 (A) and 4 (B), the lead frame 2 is formed by three-dimensionally bending a strip plate-like conductor. A step portion is appropriately formed so as to form a step in the vertical direction on a linear strip piece that is continuously formed perpendicular to the plane. Further, the lead frame 2 is not limited to one, but is composed of a plurality of different shapes (see FIG. 4A). The insert of the lead frame 2 into the base plate 11 is completed by casting the lead frame 2 when the circuit case 1 is resin-molded.

  In the insert structure of the lead frame 2, there is a portion exposed to the outside with respect to the base plate 11. The exposed part is a part to which the terminal 41 of the power device 4 is fixed by resistance welding [see FIGS. 2 and 3A]. A portion where the lead frame 2 is exposed to the outside of the base plate 11 is formed with an exposed opening 14 as an opening hole in the base plate 11, and a part of the lead frame 2 inserted into the base plate 11 is part of the exposed opening 14. (See FIGS. 2A, 3C, and 3D).

  A part of the lead frame 2 exposed from the exposed opening 14 to the outside of the base plate 11 is disposed in parallel with the plate surface of the base plate 11 (see FIG. 2A). A plurality of the exposed openings 14 are formed on both the inner surface side 1 a and the outer surface side 1 b of the base plate 11. The exposed opening 14 is preferably formed in a square shape such as a square or a rectangle, but is not particularly limited to a square shape, and may be a circular shape as necessary.

  The positions of the plurality of exposed openings 14, 14,... Formed on the inner surface side 1a and the outer surface side 1b of the base plate 11 are formed at corresponding positions at the same position on the inner surface side 1a and the outer surface side 1b. [Refer to Drawing 2 (B) and (C), Drawing 3 (C), and (D)]. That is, the exposed opening 14 is also formed on the outer surface 1b so as to be in the same position as the exposed opening 14 formed on the inner surface 1a of the base plate 11 [FIG. (See (D)).

  The lead frame 2 inserted into the base plate 11 changes in shape of the exposed opening 14 depending on the depth from the surface of the base plate 11. For example, the lead frame 2 is connected to the surface (inner surface side) of the base plate 11. If it is in a deep position from 1a and the outer surface side 1b), the exposure opening part 14 will become a hollow shape (refer FIG.3 (C)). In the case where the lead frame 2 is simply covered with a thin film at a position extremely shallow from the surface (the inner surface side 1a, the outer surface side 1b) of the base plate 11, the surface of the base plate 11, the lead frame 2, and the like. Are substantially in the same plane (see FIG. 3D).

  In the insert structure of the lead frame 2 with respect to the base plate 11, the lead frame 2 is exposed to the outside of the base plate 11 through the exposed opening 14. For this reason, the exposed opening portion is formed when the circuit case 1 is resin-molded. By using a mold in which 14 locations are formed, a part of the lead frame 2 can be easily exposed to the outside of the base plate 11 together with the exposed opening 14. The terminals 41, 41,... Of the power device 4 are fixed to a part of the lead frame 2 exposed to the outside of the base plate 11 from the exposed opening 14 by resistance welding. The circuit board 3 is installed on the closed peripheral wall portion 13 on the inner surface side 1a.

  As described above, the positions of the exposed openings 14, 14,... Correspond to the inner surface 1a and the outer surface 1b of the base plate 11 at the same position, so that the inner surface 1a and the outer surface of the base plate 11 correspond to each other. 1b is an extremely suitable configuration for connecting an electronic component such as the power device 4 to the lead frame 2 by resistance welding. In resistance welding, the lead frame 2 and the terminal 41 of the power device 4 are brought into contact with each other, the electrodes T and T are pressed against both surfaces of the lead frame 2, and a large current is applied to the lead frame 2 in a state where a load is applied. Thus, it is a structure convenient for using the welding means by resistance welding.

  The base plate 11 of the circuit case 1 is not actually a completely flat surface, and has some unevenness for mounting the circuit board 3 and the power device 4 and the like. The positions of the two exposed portions in the height direction are also different. Therefore, as described above, the lead frame 2 has a stepped surface formed in the vertical direction on the band plate through the stepped portion so that it can correspond to the respective positions on the inner surface side 1a and the outer surface side 1b of the base plate 11. The position in the height direction is changed. That is, the lead frame 2 has a shape obtained by appropriately and intricately combining a bent portion perpendicular to the band plate and a parallel portion due to a step (see FIG. 4B).

  As described above, in the power device 4, the terminals 41, 41,... Are resistance-welded to the exposed surface of the lead frame 2. This enables resistance welding of the terminals 41, 41,... Of the power device 4 in a state of being parallel and lying down on the base plate 11 of the circuit case 1, and the dimension of the power device 4 in the height direction from the base plate 11. Can be minimized.

  The terminals 41, 41,... Of the power device 4 and a part of the lead frame 2 exposed from the exposed opening 14 of the base plate 11 need only be energized. For example, resistance welding, laser welding, spot welding, It may be a fixing means such as caulking or soldering. The lead frame 2 is configured to be inserted into the base plate 11 of the circuit case 1, and the power circuit by the power device 4 does not exist on the substrate, and is directly on the outer surface side 1 b of the base plate 11 of the circuit case 1. Installed. The wiring between the electric elements of the power device 4 is carried by the lead frame 2 inserted in the base plate 11, thereby eliminating the need for a power substrate. As a result, the circuit board 3 as a control circuit and the power device 4 as a power circuit can be substantially separated by the base plate 11 (see FIG. 1B).

  The power device 4 is a power electronic component such as an FET, and serves to supply electric power to the coil of the motor unit. The circuit board 3 serves to control the power device 4. And the circuit board 3 is installed in the closed surrounding wall part 13 formed in the inner surface side 1a of the base board 11, and this circuit board 3 contacts the lead frame 2 exposed to the exposed opening part 14 in the closed surrounding wall part 13 so that electricity supply is possible. Is done. The circuit board 3 installed in the closed peripheral wall portion 13 is filled with a coating resin R such as silicone gel so that the circuit board 3 is covered with the resin.

  The coating resin R is filled so as to cover the circuit board 3 and serves to protect the electrical elements on the circuit board 3 and to dissipate heat or to insulate. The potting material such as silicone gel, urethane, ceramic, epoxy, etc. The material is used. The power device 4 that is a heat generating component is disposed in contact with or close to the back surface of a heat sink C, which will be described later, and the power device can effectively dissipate heat by the fins of the heat sink C.

  The closed peripheral wall portion 13 constitutes a peripheral wall that is closed in a planar shape. Specifically, the closed peripheral wall portion 13 completely surrounds the outer periphery of the circuit board 3 placed on the inner surface 1 a of the base plate 11. The molten coating resin is filled in the closed peripheral wall portion 13 to protect the circuit board 3. The closed peripheral wall portion 13 is formed so as to be substantially the same as the planar outer peripheral shape of the circuit board 3.

  In the motor part B, an iron alloy stator 6 and an inner magnet 7 are mounted inside the motor housing 5. In the stator 6, a coil 62 is wound around a stator core 61, and these are covered with a resin 63 and are waterproof. The magnetic field is switched by sequentially switching the energization of the coil 62 wound around the stator core 61 by control, and the inner magnet 7 disposed near the axis center can be rotationally driven. If the inner magnet 7 is rotated by the magnetic force of the stator 6, the impeller that is integrally attached to the inner magnet 7 rotates, and can function as a pump.

  The engine coolant enters the area near the axis of the motor part B and up to the region where the inner magnet 7 and the impeller shaft 92 are disposed. That is, cooling water is also present in the inner peripheral region of the motor part B. Therefore, on the side far from the impeller 91 blade and in the vicinity of the shaft end of the impeller shaft 92, a partition wall 51 made of resin or aluminum alloy that partitions the motor portion B and the motor control portion A is formed in a substantially disc shape. Yes. The partition wall 51 is a boundary between the motor part B and the motor control part A, and is a wall for sealing the cooling water [see FIG. 1 (A)].

  The motor part B is configured to allow fluid to enter the inner peripheral side of the motor housing 5. Since the stator 6 is generally a heat generating component, the heat of the stator 6 is radiated by the fluid that enters the inner peripheral side of the motor housing 5. Therefore, the heat of the stator 6 is difficult to be transmitted to the circuit board 3 on the motor control unit A side. Since the fluid and the circuit board 3 are close to each other via the partition wall 51, the heat of the circuit board 3 is easily radiated by the fluid, and the temperature rise of the circuit board 3 can be suppressed.

  The pump unit 9 includes a resin impeller 91 in which a plurality of blades are radially arranged evenly in the circumferential direction, and an iron alloy impeller shaft 92 that is fixed to the impeller 91 and disposed at the center of rotation of the impeller. It consists of. The impeller 91 is integrated with an inner magnet 7 that is a permanent magnet disposed in the motor part B. The inner magnet 7 is formed of a plastic magnet.

  A heat sink C is attached to the outer surface side 1 b of the circuit case 1. The heat sink C is made of an aluminum alloy, and a power device 4 such as an FET is mounted thereon. The power device 4 can effectively dissipate heat by being placed in contact with or close to the back surface of the heat sink C.

A ... Motor control unit, B ... Motor unit, 1 ... Circuit case, 11 ... Base plate,
14 ... exposed opening, 2 ... lead frame, 3 ... circuit board, 4 ... power device,
41 ... terminal, 8 ... pump part.

Claims (3)

A motor control unit that is connectable to a motor unit mounted on a pump unit and has a base plate, a circuit board, and a power device, the motor control unit comprising the pump unit, the motor unit, and the motor control unit A lead frame is insert-molded in the base plate, and an exposed opening is provided on the outer surface side of the base plate where a part of the lead frame is exposed in parallel with the plate surface of the base plate. is formed on the at the outer surface side of the base plate terminal of the power device via the exposed opening is welded and fixed, is arranged the circuit board in a closed peripheral wall portion formed on an inner surface side of the base plate the power device is controlled by a circuit board, so that the same position in response to the exposure opening portion formed in the outer surface side to the inner surface side of the base plate Serial exposure opening is formed, the circuit board is an electric pump, characterized in that formed by contact with energizable and the lead frame exposed on the exposed opening in the closure wall portion.   2. The electric pump according to claim 1, wherein the exposed opening is formed in a hollow shape.   2. The electric pump according to claim 1, wherein the exposed opening and the lead frame are flush with each other.

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