JP5960630B2 - Electronic control unit - Google Patents

Description

  The present invention relates to an electronic control device that controls an electric actuator.

  In recent years, techniques using electric actuators such as regenerative cooperative braking have become widespread.For example, an electric actuator that performs brake control via an electric motor and an electric motor based on a brake operation by a driver, a driving state of an automobile, etc. A configuration combining an electronic control device that controls driving is known.

  Further, Patent Document 1 discloses an electric power steering device in which the electric motor and the electronic control device have an electromechanical integrated structure.

  Furthermore, in an automatic transmission with an electromechanical integrated structure, Patent Document 2 discloses a structure in which a cover is provided on the cover of the electronic control device to prevent direct moisture on the seal joint between the case of the electronic control device and the cover. Yes.

JP 2002-127721 A JP 2010-71348 A

  However, in patent document 2, there existed a possibility that a water | moisture content may approach by the capillary phenomenon between the case of an electronic controller, and a collar. If such a state is left excessively, impurities (salt content, calcium, etc.) contained in water may be gradually crystallized and deposited, and there is a concern about the influence.

  The present invention has been devised in view of such technical problems, and in an electronic control device having an electromechanical integrated structure, it is an object to ensure the robustness of the sealing performance of the seal coupling portion.

  The present invention is an electronic control device having a case and a cover for housing a circuit board, wherein a part of the bottom wall of the case is seal-coupled to a cylindrical wall forming an opening of an electric motor, A protrusion protruding to the electric motor side is formed on the outer edge side of the seal coupling portion in the case bottom wall, and the length of the protrusion in the protruding direction is a cylindrical wall of the protrusion and the electric motor due to capillary action. The size is such that moisture is not drawn between the two.

  According to the present invention, it is possible to secure the robustness of the sealing performance of the seal coupling portion in the electronic control device having an electromechanical integrated structure.

It is an exploded perspective view of an actuator unit provided with the electronic control unit in an embodiment. It is a disassembled perspective view of the electronic control unit in an embodiment. It is the perspective view which looked at the case of the electronic control unit in an embodiment from the lower part side. It is the top view which looked at the electronic control unit in an embodiment from the lower part side. It is a fragmentary sectional view showing an electronic controller outline. It is AA sectional drawing of the actuator unit of FIG. It is a schematic sectional drawing which shows the seal | sticker coupling | bond part and projection part of the actuator unit in embodiment. It is a schematic sectional drawing which shows the other example of the seal | sticker coupling | bond part and projection part of an actuator unit.

  Hereinafter, an example in which the electronic control device according to the present embodiment is applied to an electric actuator for a brake of an automobile will be described in detail with reference to FIGS.

  First, an actuator unit 1 shown in FIG. 1 is used for an electric brake booster mounted on an automobile, and is an electric actuator that is driven by three-phase AC power and controls the hydraulic pressure of brake fluid. An electric motor 2 and a motor control device (hereinafter referred to as an electronic control device) 3 that drives and controls the electric motor 2 based on a brake operation by a driver and a driving state of the automobile are provided. In addition, although illustration is abbreviate | omitted, the electric motor 2 moves the piston which is not shown in figure which controls the hydraulic pressure of brake fluid by a so-called ball screw mechanism.

  On the cylindrical outer surface of the motor housing 4 of the electric motor 2, a pair of pedestal portions 5 extending in the axial direction of the electric motor 2 are formed at predetermined intervals in the direction perpendicular to the axis of the electric motor 2. A circular seating surface 6 with screw holes 6a is formed at both ends in the longitudinal direction of both pedestal portions 5 while projecting and formed on a case 12 (described later) of the casing 7 of the electronic control unit 3. Are formed with four leg portions 8 respectively seated on the respective seating surfaces 6 on the motor housing 4 side. The electronic control device 3 is fixed to the electric motor 2 by four control device mounting screws 9 that are screwed into the screw holes 6a on the motor housing 4 side while inserting the leg portions 8 on the housing 7 side.

  On the other hand, a substantially rectangular cylindrical wall 10 protrudes from the motor housing 4 at a position between the pedestals 5, and when the casing 7 of the electronic control device 3 is fixed to the motor housing 4, the electronic control is performed. The stator connecting portion 20 (see FIGS. 2 and 4) and the rotational position sensor connecting portion 23 (see FIG. 4) on the apparatus 3 side are provided in the motor housing 4 through the opening 11 opened to the inner peripheral side of the cylindrical wall 10. It comes to face. Examples of the stator connection portion 20 include those having terminals connected to a stator (not shown) in the motor housing 4. In the rotational position sensor connection portion 23, a harness (not shown) from the rotational position sensor in the motor housing 4 is connected. As is well known, this rotational position sensor detects the rotational position of a rotor (not shown) provided in the motor housing 4, and the output signal of the rotational position sensor is electrically driven by the electronic control unit 3. What is used for drive control of the motor 2 is mentioned.

  An endless continuous groove 10 a is formed at the tip of the cylindrical wall 10 surrounding the opening 11, and a seal member (not shown) disposed in the groove 10 a is pressed against the bottom wall of the case 12. As a result, the inside and outside of the motor housing 4 are sealed.

  As shown in FIGS. 1 and 2, the housing 7 of the electronic control device 3 includes a case 12 and a cover 15. The case 12 has a bottom wall 13 and a peripheral wall 14 surrounding the four sides, and has a substantially rectangular shape in a plan view in which an upper surface opens upward. The cover 15 has a substantially rectangular shape in a plan view that closes the upper surface opening of the case 12. A power module 16 corresponding to a “circuit board” and a control module 17 corresponding to a “second circuit board” are accommodated in the housing 7. Specifically, the power module 16 is positioned near the bottom wall 13 of the case 12, and the control module 17 is laminated and disposed above the power module 16 with a predetermined interval. The housing 7 is fixed to the motor housing 4 with the bottom wall 13 of the case 12 facing the motor housing 4 side.

  As shown in FIGS. 1 and 2, the cover 15 is formed, for example, by press-molding a metal plate in a substantially dish shape, and on the opposite side to the case 12 to accommodate the control module 17. A bulging portion 43 bulging out, a flange portion 44 formed on the outer peripheral edge of the bulging portion 43, and a protruding edge portion formed by bending the outer peripheral edge of the flange portion 44 downward (case 12 side). 45.

  As shown in FIG. 2, the case 12 is formed by a so-called aluminum die casting method using, for example, an aluminum alloy having relatively good heat conduction. In the first wall portion 14a corresponding to one side of the rectangular peripheral wall 14 in the case 12, an opening 36 through which the external connection connector 19 on the power module 16 side is inserted has a large portion of the first wall portion 14a on the upper side. It is formed so as to be cut out from. The opening 36 has a shape that matches the flange portion 19a formed at the base of the external connector 19, and the opening edge of the opening 36 is provided with an adhesive sealing material (not shown). The flange portion 19a is bonded and fixed. 2 indicates a cooling fin formed on the outer surface of the case 12.

  A continuous seal groove 46 is formed at the front end edge of the peripheral wall 14 of the case 12 and the upper end edge of the flange portion 19 a of the external connection connector 19. The cover 15 and the case 12 are fastened and fixed by a plurality of cover mounting screws 34 in a state where the protruding edge 45 on the cover 15 side is inserted into the seal groove 46. Although not shown, the gap between the cover 15 and the case 12 can be sealed by filling the seal groove 46 with a sealing material.

  The bottom wall 13 of the case 12 is formed with four substantially cylindrical power module support portions 37 protruding from the positions near the four corners of the bottom wall 13 toward the cover 15. A screw hole 37 a into which the power module mounting screw 61 is screwed is formed at the top of each power module support portion 37. Furthermore, in the position corresponding to the mounting area (not shown) of the switching element provided on the power module 16 side in the bottom wall 13, as a heat receiving part, a substantially rectangular block shape from the bottom wall 13 toward the cover 15 side. A block-shaped protruding portion 38 protruding in the shape of is formed. This block-shaped protrusion 38 functions as a heat sink having a large heat capacity.

  The block-shaped protruding portion 38 is located at a substantially central portion of the case 12 and is separated from the first wall portion 14a and the second wall portion 14b facing each other out of the rectangular peripheral wall 14 with a predetermined interval therebetween. The fourth wall portion 14d facing the third wall portion 14c having the cooling fins 12a is also separated by a predetermined distance. And the block-shaped protrusion part 38 is integrally formed continuously by the 3rd wall part 14c which has the fin 12a for cooling. A total of four screw holes 38 a into which the power module mounting screws 62 are screwed are formed in the vicinity of the four corners of the top surface of the block-shaped protruding portion 38.

  2 and 3 is a connector insertion hole 40 having a substantially rectangular cross section formed through the end of the block-shaped protruding portion 38 on the third wall portion 14c side. The reference numeral 39 denotes a power supply terminal insertion hole 39 formed through the corner portion formed by the end wall on the fourth wall portion 14 d side of the block-shaped protruding portion 38 and the bottom wall 13 of the case 12. Further, reference numeral 41 in FIG. 2 is formed through the third wall portion 14c at a position closer to the second wall portion 14b than the block-shaped protruding portion 38, and allows breathing air to pass air but not water (see FIG. 1). Is the breathing hole attached.

  As shown in FIG. 2, the power module 16 is molded by using, for example, a synthetic resin material. The power module 16 is formed in a substantially flat plate shape, and a metal bus bar (not shown) is inserted on the surface or inside. The plate-like base portion 18, the external connection connector 19 integrally formed at one end edge of the plate-like base portion 18, and the above-described stator protruding from the plate-like base portion 18 in a direction perpendicular to the plane of the plate-like base portion 18. A connection unit 20 and a sensor connection unit 23 (see FIG. 4). The external connection connector 19 corresponds to a “power supply connector”, faces the outside through the opening 36 on the case 12 side, and exchanges signals and electric power with external electronic devices. Various electronic components are mounted on the component mounting surface that is the surface of the plate-like base 18 on the case 12 bottom wall 13 side. The stator connection portion 20 protrudes from a substantially central portion of the component mounting surface. In addition, the sensor connection portion 23 protrudes from one end edge of the component mounting surface. The stator connection portion 20 and the sensor connection portion 23 each have a rectangular plate shape and extend in parallel to each other.

  Further, as shown in FIG. 2, the control module facing surface 18c on the side opposite to the component mounting surface 18a in the plate-like base portion 18 projects from the outer peripheral edge of the control module facing surface 18a in the direction perpendicular to the surface. A plurality of snap-fit portions 47 for engaging and holding the module 17 by a so-called snap-fit method are formed, and a plurality of connection terminals 52 for electrically connecting the power module 16 and the control module 17 are provided. .

  In the assembled state, the control module 17 is seated on the control module support portion 48, and the tip (claw-like tip) of the holding piece 49 is engaged with the cover facing surface 17 b of the control module 17. . As a result, the control module 17 is placed at a position spaced apart from the plate-like base 18 in a direction perpendicular to the plane, specifically, at a position where the control module 17 enters the cover 15 from the opening end of the case 12. Positioned and held by the portion 47. That is, the control module 17 is accommodated in the bulging portion 43 of the cover 15.

  As shown in FIG. 2, the control module 17 forms wiring patterns (not shown) on both the front and back surfaces of a substrate made of a non-conductive resin material represented by, for example, glass epoxy resin, on which various electronic components are formed. It is configured by mounting components (not shown), and the cross-sectional shape of the body portion of each holding piece 49 is located at a position corresponding to each holding piece 49 on the outer peripheral edge of the control module 17. Are formed in the shape of the notch 17c. That is, the control module 17 is positioned in a state parallel to the plate-like base portion 18 by receiving the body portion of each holding piece 49 in each notch portion 17c.

  As shown in FIG. 2, through holes 53 are formed through the control module 17 at positions corresponding to the connection terminals 52 on the power module 16 side. Each through-hole 53 receives a corresponding connection terminal 52 and is electrically connected to the connection terminal 52 by solder. Then, the control module 17 inputs and calculates information related to the brake operation by the driver and the driving state of the vehicle to the CPU (not shown) or the like via the external connection connector 19 and each connection terminal 52, and based on the information. The drive command signal generated in this manner is output to each switching element (not shown) provided in the power module 16 via each connection terminal 52, so that the switching motor is driven to drive the electric motor 2. become.

  As described above, the electric motor 2 and the electronic control device 3 (case 12) are inserted by the plurality of control device mounting screws 9 in a state where the seal member (for example, an O-ring) 70 is inserted into the groove portion 10a of the electric motor 2. And the sealing member 70 is pressed against each other to seal the inside and outside of the motor housing 4 and the inside and outside of the electronic control unit 3. As shown in FIGS. 3, 4, and 6, when the electric motor 2 and the electronic control device 3 are assembled, the seal member 70 is disposed so as to surround the connector insertion hole 40 and the power supply terminal insertion hole 39. Is done.

  As shown in FIGS. 3, 4, and 6, a protrusion 71 projecting toward the electric motor 2 so as to surround the seal member 70 from the outer edge side of the seal member 70 in the bottom wall 13 of the case 12. Is formed. In addition, since the part which the said protrusion part 71 interrupted protrudes from the bottom wall 13 of the case 12 to the electric motor 2 side other than the protrusion part 71, formation of the protrusion part 71 was abbreviate | omitted about the part It is.

  As shown in FIG. 5, the length a in the projecting direction of the protrusion 71 in the first embodiment only needs to be high enough to guide moisture in the falling direction of the side wall 14 of the case 12. Further, the length a of the protruding portion 71 in the protruding direction is formed shorter than the shortest length among the lengths in which capillary action is caused between the side wall 14 of the case 12 and the cylindrical wall 10 to raise moisture. The Further, the length a of the protruding portion 71 in the protruding direction is formed to be smaller than the distance b between the cylindrical wall 10 of the motor housing 4 and the protruding portion 71. Further, the length a of the protruding portion 71 in the protruding direction is shorter than the thickness c of the bottom wall 13 of the case 12. Further, the distance b between the cylindrical wall 10 and the protruding portion 71 is also formed to a size such that moisture does not enter between the side wall 14 of the case 12 and the cylindrical portion 10 due to capillary action.

  When the seal member 70 is used for an electric motor 2 or an electronic control device 3 mounted on a vehicle having a severe use environment, the degree of deterioration is remarkable. Become. Here, the moisture that has dropped onto the cover 15 of the electronic control device 3 is transmitted from the side wall 14 of the case 12 to the bottom wall 13 and is wetted by the seal member 70. When the sealing member 70 is flooded in this way, moisture enters the deteriorated portion of the sealing member 70, and in some cases, corrosion proceeds, and the strength of the bonding surface in the corroded portion may further decrease.

  Here, as in the present embodiment, the protrusion 71 is provided on the outer edge side of the seal coupling portion with the cylindrical wall 10 in the bottom wall 13, so that the moisture transmitted through the side wall 14 of the case 12 is the protrusion 71. As a guide path, and falls from the protrusion 71 without being transmitted to the bottom wall 13 of the case 12. As a result, it is possible to prevent moisture from being transferred to the bottom wall 13 of the case 12 and being wetted by the seal member 70, and deterioration of the seal member 70 can be suppressed. For this reason, the electronic control device 3 and the electric motor 2 are kept sufficiently airtight by the seal member 70.

  Further, as in Patent Document 2, when the length a of the protruding portion 71 in the protruding direction is formed long, moisture transmitted through the side wall 14 of the case 12 is between the protruding portion 71 and the cylindrical wall 10 due to a capillary phenomenon. There is also a possibility of entering into the water, and if it is left too much, impurities (salt content, calcium, etc.) contained in the water may gradually crystallize and deposit, and there is a concern about the influence.

  However, in this embodiment, since the length a of the protruding portion 71 in the protruding direction is formed short, it is possible to prevent moisture that has traveled along the side wall 14 of the case 12 from entering between the protruding portion 71 and the cylindrical wall 10 due to capillary action. can do. As a result, it is possible to prevent the case 12 from being deformed due to the crystallization of impurities (such as salt and calcium) contained in moisture gradually between the side wall 14 and the cylindrical wall 10 of the case 12, It becomes possible to suppress a decrease in sealing performance between the cylindrical wall 10 and the bottom wall 13.

  Further, since the length a of the protruding portion 71 in the protruding direction is shorter than the thickness c of the bottom wall of the case 12, impurities contained in moisture between the cylindrical wall 10 and the side wall 14 of the case 12 ( Even if the salinity, calcium, etc.) are crystallized, the stress due to the crystal is related to the bottom wall 13 of the case 12, so that the stress on the protrusion 71 is relaxed and the warping of the protrusion 71 can be suppressed. . As a result, a decrease in sealing performance between the cylindrical wall 10 and the bottom wall of the case 12 due to the sealing member 70 is suppressed, and the air tightness of the electric motor 2 and the electronic control device 3 is maintained by the sealing member 70.

  As shown in FIG. 7, in the present embodiment, the protrusion 71 is formed at the outer edge of the bottom wall 13, and the root of the protrusion 71 is substantially L-shaped. Here, as shown in FIG. 8, the protrusion 71 may be formed between the seal member 70 and the outer edge of the bottom wall 13. That is, in FIG. 8, the protrusion 71 is not formed at the outer edge of the bottom wall 13 but is formed slightly toward the seal member 70 from the outer edge of the bottom wall 13.

  In this manner, by forming the protruding portion 71 slightly on the seal member 70 side from the outer edge of the bottom wall 13, the root portion of the protruding portion 71 becomes T-shaped. Therefore, even if impurities (salt content, calcium, etc.) contained in moisture are crystallized between the protrusion 71 and the cylindrical wall 10, stress due to the crystallization escapes from the protrusion 71 to the bottom wall 13. Compared to the case where the portion is L-shaped, warping of the protrusion 71 can be suppressed. As a result, a decrease in sealing performance due to the sealing member 70 is suppressed, and sufficient airtightness of the electric motor 2 and the electronic control device 3 is maintained by the sealing member 70.

  Moreover, by forming the length a in the protruding direction of the protrusion 71 short, it is possible to facilitate the assembly to the vehicle and to suppress interference with the motor housing 4.

DESCRIPTION OF SYMBOLS 1 ... Actuator unit 2 ... Electric motor 3 ... Electronic control apparatus (motor control apparatus)
DESCRIPTION OF SYMBOLS 10 ... Cylindrical wall 11 ... Opening part 12 ... Case 15 ... Cover 16 ... Power module (circuit board)
17 ... Control module (second circuit board)
70 ... Sealing member 71 ... Projection part a ... Length in the protrusion direction of the projection part b ... Distance between the projection part and the cylindrical wall c ... Thickness of the case bottom wall

Claims (3)

An electronic control device having a case and a cover for housing a circuit board, wherein a part of the bottom wall of the case is seal-coupled to a cylindrical wall forming an opening of the electric motor,
On the outer edge side of the seal bottom portion of the case bottom wall with the cylindrical wall of the electric motor, a protrusion protruding to the electric motor side is formed,
The length of the protrusion method of the protrusion is shorter than the shortest length among capillaries in which moisture is drawn between the protrusion and the cylindrical wall of the electric motor. apparatus.   The electronic control device according to claim 1, wherein a length of the protruding portion in a protruding direction is shorter than a thickness of the case bottom wall. The protrusion is
2. The electronic control device according to claim 1, wherein the electronic control device is formed between an outer edge of the case bottom wall and a seal coupling portion of the electric motor.

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