JP2013062334A - Electronic control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an electronic control device which at least eases a pressure difference between the interior and the exterior of a seal material enclosing a screw member and thereby inhibiting the peeling of the seal material and the deterioration of the sealability.SOLUTION: In an electronic control device, a circuit board is housed in a housing 7 composed of a case 12 opening in one direction and a cover 15 closing the opening of the case 12, and a space between the case 12 and the cover 15 is sealed by an adhesive 44 which is applied to a seal groove 35, formed along an opening edge of the case 12, as a sealing material. A boss part 39, with which a cover attachment screw 45 serving as a screw member threadedly engages, is enclosed by the adhesive 44, and a gap S2 between the boss part 39 and the adhesive 44 communicates with an exterior space of the housing 7 through an air passage 48.

Description

  The present invention relates to an electronic control device.

  For example, as described in Patent Document 1, in an electronic control device in which a circuit board is accommodated in a case and the opening of the case is closed by a lid, a seal groove is formed at the opening edge of the case The case and the lid are sealed by a sealing material provided in the sealing groove.

JP 2010-132103 A

  By the way, although the through hole for fixing the said lid | cover to a case with a screw member is formed in the lid | cover in the technique of patent document 1, in such a case, it goes into the case through the said through hole. In order to prevent water and dust from entering, the outer peripheral side of the boss portion to which the screw member of the case is screwed is surrounded by a part of the seal groove, and the penetration is made by the seal material provided in the surrounding portion. It is desirable to seal between the hole and the internal space of the case.

  However, when a sealing material is provided so as to surround the boss portion, the air existing in the gap between the boss portion and the sealing material expands or contracts due to a temperature change, so that the gap and the case There is a possibility that a pressure difference is generated between the inner space and the sealing material is peeled off from the lid due to the pressure difference and the sealing performance is deteriorated.

  The present invention has been made in view of the problems as described above, and at least relaxes the pressure difference between the gap and the internal space of the case, thereby suppressing the peeling of the sealing material from the lid. An object of the present invention is to provide an electronic control device that suppresses deterioration in sealing performance.

  In particular, the present invention is characterized by including an air passage that communicates the gap between the boss portion and the sealing material and the external space of the housing.

  According to the present invention, when the air existing in the gap between the boss portion and the sealing material expands or contracts, the air is supplied to and discharged from the gap through the air passage. The pressure difference between the inner space and the inner space is relieved at least, and the peeling of the sealing material from the lid body is suppressed, so that the sealing performance can be prevented from being lowered.

1 is an exploded perspective view showing an actuator unit to which an electronic control device according to the present invention is applied as an embodiment of the present invention. The exploded perspective view which looked at the actuator unit in Drawing 1 from another angle. The perspective view which decomposes | disassembles and shows the motor control apparatus in FIG. Sectional drawing in alignment with the AA of the motor control apparatus in FIG. The top view which shows the state which removed the cover from the motor control apparatus in FIG. The expansion perspective view which shows the detail of the boss | hub part in FIG. It is BB sectional drawing of FIG. 6, Comprising: The figure which shows the state which closed the case with the cover.

  1 to 7 are views showing a preferred embodiment of the present invention, in which FIG. 1 is an exploded perspective view showing an actuator unit to which an electronic control device according to the present invention is applied, and FIG. 2 is shown in FIG. It is the disassembled perspective view which looked at the actuator unit from another angle. 3 is an exploded perspective view of the electronic control device, FIG. 4 is a cross-sectional view taken along line AA of the electronic control device shown in FIG. 2, and FIG. 5 is a plan view showing the electronic control device with the cover removed. It is.

  The actuator unit 1 shown in FIGS. 1 and 2 is used in 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 the brake fluid. There is provided an electric motor 2 and a motor control device 3 as an electronic control device that drives and controls the electric motor 2 based on a brake operation by a driver and a driving state of an automobile. In addition, although illustration is abbreviate | omitted, the electric motor 2 will move forward and backward the piston which is not shown in figure which controls the hydraulic pressure of brake fluid with what is called a ball screw mechanism.

  A pair of pedestal portions 5 extending in the axial direction of the electric motor 2 are formed on the outer surface of the motor housing 4 that is an actuator housing of the electric motor 2 at a predetermined interval in the direction perpendicular to the axis of the electric motor 2. Yes. Circular seating surfaces 6 each having a screw hole 6a are formed at both ends in the longitudinal direction of both pedestal portions 5 so as to project from each other, while a case 12 (to be described later) of the casing 7 of the motor control device 3 is formed. Are formed with four leg portions 8 respectively seated on the respective seating surfaces 6 on the motor housing 4 side. Then, the motor control device 3 is fixed to the electric motor 2 by the four control device mounting screws 9 screwed into the screw holes 6a on the motor housing 4 side while inserting the leg portions 8 on the housing 7 side. become.

  On the other hand, when the housing 7 of the motor control device 3 is fixed to the motor housing 4, a substantially flat rectangular tubular wall 10 is formed at a position between the pedestal portions 5 of the motor housing 4. A stator connecting portion 20 and a sensor connecting portion 21 described later on the motor control device 3 side face the motor housing 4 through the opening 11 that opens to the inner peripheral side of the cylindrical wall 10. The stator connecting portion 20 is connected to a stator (not shown) in the motor housing 4, and the sensor connecting portion 21 is connected to a rotational position sensor (not shown) in the motor housing 4. As is well known, the 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 a motor control device. 3 is used for the drive control of the electric motor 2 by 3. Further, a closed loop groove 10a is formed at the tip of the cylindrical wall 10, and a seal member (not shown) disposed in the groove 10a is in pressure contact with the bottom wall 13 of the case 12, so that the motor housing The inside and outside of 4 are sealed.

  As shown in FIG. 3 in addition to FIGS. 1 and 2, the housing 7 of the motor control device 3 has a bottom wall 13 and a peripheral wall 14, and is a metal case 12 having a substantially rectangular shape in plan view that opens upward. And a metal cover 15 having a substantially rectangular shape in plan view, which is a lid that closes the opening of the case 12, and the substrate housing space S <b> 1 formed inside the housing 7 includes a cover. In the order of the control module 17 and the power module 16 from the 15 side, the both 16 and 17 are stacked and arranged as a circuit board at 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. 3 and 4, the power module 16 is formed of a resin material in a substantially flat plate shape, a plate-like base portion 18 in which a large number of metal bus bars (not shown) are embedded, and the plate-like base portion 18. Among them, various electronic components mounted on the component mounting surface 18a facing the bottom wall 13 side of the case 12 and one end edge of the plate-like base 18 are integrally formed, and through an opening 31 described later on the case 12 side. Facing the outside (see FIG. 2), the external connection connector 19 for exchanging signals and electric power with external electronic devices, and the component mounting surface 18a of the plate-like base 18 are projected from the stator (not shown) of the electric motor 2. And a stator connection portion 20 that is electrically connected to the above-described rotational position sensor (not shown) and is protruded from the component mounting surface 18a of the plate-like base portion 18. 21 (Figure Is provided with a reference), the.

  As shown in FIG. 1, the power module 16 includes a stator connection portion 20 in the power supply terminal insertion hole 33 formed in the bottom wall 13 of the case 12 and a connector insertion hole formed in the bottom wall 13 of the case 12. As shown in FIG. 3, with the sensor connection portions 21 inserted into the respective 34, the case 12 is provided with a plurality of power module mounting screws 23 that respectively pass through the plurality of mounting holes 22 penetratingly formed in the plate-like base portion 18. It is fastened and fixed to. 3 indicates a screw hole on the case 12 side into which the power module mounting screw 23 is screwed.

  As shown in FIGS. 3 and 4, the control module facing surface 18b on the opposite side of the component mounting surface 18a of the plate-like base 18 protrudes from the outer peripheral edge of the control module facing surface 18b in a direction perpendicular to the surface. A plurality of snap fit portions 25 for engaging and holding the control module 17 by a so-called snap fit method and a plurality of connection terminals 26 for electrically connecting the power module 16 and the control module 17 are provided.

  On the other hand, the control module 17 forms conductor patterns (not shown) on both the front and back surfaces of a substrate made of a non-conductive resin material typified by glass epoxy resin, and a large number of electronic components (not shown) thereon. 1), and each of the snap fit portions 25 on the power module 16 side is spaced apart from the plate-like base portion 18 on the power module 16 side by a predetermined distance in the plane perpendicular direction. Specifically, it is positioned and held at a position closer to the cover 15 than the opening end of the case 12.

  As shown in FIGS. 3 and 5, through holes 27 through which the connection terminals 26 are inserted are formed at positions corresponding to the connection terminals 26 on the power module 16 side of the control module 17. Yes. Each connection terminal 26 on the power module 16 side passes through each through hole 27 and protrudes from the control module 17 to the cover 15 side, and is electrically connected to each through hole 27 with solder (not shown).

  That is, the control module 17 inputs information on the brake operation by the driver and the driving state of the vehicle via the external connection connector 19 and each connection terminal 26, and also connects the drive command signal generated based on the information to each connection. The power is output to the power module 16 via the terminal 26. The power module 16 supplies power to the electric motor 2 based on the drive command signal input from the control module 17 and drives the electric motor 2.

  As shown in FIGS. 3 and 4, the cover 15 of the housing 7 is formed by pressing a metal plate in a substantially dish shape, and faces the side opposite to the case 12 to accommodate the control module 17. The bulging portion 28 that bulges, the flange portion 29 extending from the outer peripheral edge of the bulging portion 28 toward the outer peripheral side, and the outer peripheral edge of the flange portion 29 are bent downward (case 12 side). And a projecting edge portion 30.

  On the other hand, as shown in FIGS. 3 and 5, the case 12 is molded by a so-called aluminum die casting method, and the power module 16 side is provided on one side of the peripheral wall 14 having a substantially rectangular shape in plan view. An opening 31 for receiving the external connection connector 19 is cut out from above. The opening 31 has a shape that matches the flange portion 19a formed at the base of the external connection connector 19, and the opening edge of the opening 31 is flanged by a sealing material (not shown). The part 19a is bonded and fixed. 3 indicates a cooling fin formed on the outer surface of the case 12, and reference numeral 32 in FIG. 5 indicates a breathing filter that is attached to the peripheral wall 14 and allows air to pass but not water. Show.

  In addition, a sealing groove 35 that is continuous in a closed loop shape is formed in a substantially rectangular shape in plan view at the open end of the peripheral wall 14 including the upper end of the flange portion 19a in the case 12. The seal groove 35 is formed between an outer peripheral side wall 36 surrounding the outer peripheral side of the seal groove 35 and an inner peripheral side wall 37 surrounding the inner peripheral side of the seal groove 35.

  In addition, one of the side walls 36 and 37 is convex toward a direction away from the other at a predetermined position in the longitudinal direction of the seal groove 35, specifically, at a position near the four corners of the seal groove 25. The bulged portions 36a and 37a that are curved in this manner are formed, and the boss portion 39 for fixing the cover 15 to the inner peripheral side of the bulged portions 36a and 37a in the opening end of the case 12 is formed. Are protruded. As a result, the outer groove 38a along the outer peripheral side wall 36 of the seal groove 35 and the inner wall 37 along the inner peripheral side 37 of the seal groove 35 are located at positions corresponding to the bosses 39 in the seal groove 35. Enclosed portions 38 that form a closed loop with the circumferential groove 38b are formed, and the outer peripheral sides of the boss portions 39 are surrounded by the respective enclosed portions 38, respectively.

  6 is an enlarged perspective view showing details of the boss portion 39 in FIG. 5, and FIG. 7 is a cross-sectional view taken along the line B-B in FIG. 6, showing a state where the case 12 is closed by the cover 15. 6 and 7, only one of the boss portions 39 is illustrated, but the other boss portions 39 are configured in substantially the same manner.

  As shown in FIG. 6, the boss portion 39 includes a substantially cylindrical boss portion body 40 having a screw hole 41 into which a cover mounting screw 45 (see FIG. 7) described later is screwed, and the boss portion body 40. A pair of land portions 43 projecting from the root portion toward the outer peripheral side, and the outer edge shape in plan view of the entire boss portion 39 including both land portions 43 is the outer edge in plan view of the surrounding portion 38. It is set to be similar to the shape.

  That is, the corner portion 36b formed by the longitudinal end portions 36c and 36d of the bulging portion 36a and the general portion 36e of the side wall 36 is formed at a substantially right angle, and the outer edge shape in the plan view of the surrounding portion 38 is substantially semicircular or Whereas the outer edge shape of the boss main body 40 in a plan view has a substantially circular shape while having a substantially D-shape, the boss main body 40 and the side walls 36, which should be the width of the surrounding portion 38, 37 is wider than the other portions at a position corresponding to the connecting portion between the outer peripheral groove portion 38a and the inner peripheral groove portion 38b. In the plan view of the entire boss portion 39 including both the land portions 43, the land portions 43 having a substantially triangular shape in plan view are formed at positions where the gap C between them 36 and 37 is relatively wide. The outer edge is almost D-shaped It is. As a result, the width dimension W of the surrounding portion 38 is substantially uniform in the longitudinal direction of the surrounding portion 38 and is substantially the same as the general portion 35 a excluding the surrounding portion 38 in the seal groove 35.

  The boss portion main body 40 is formed higher than both side walls 36 and 37 of the seal groove 35 in the projecting direction of the boss portion main body 40, and an annular seating surface 42 formed at the tip of the boss portion main body 40. A pair of communication grooves 42 a extending from the inner peripheral edge of the seating surface 42 toward both the land portions 43 are formed.

  Then, as shown in FIG. 7, a thermosetting adhesive 44 having sealing properties is applied as a sealing material in the seal groove 35, and the protrusion 30 on the cover 15 side is inserted into the seal groove 35. While the flange portion 29 of the cover 15 is seated on the seating surface 42 of each boss portion 39, the case 12 is closed by the cover 15. Further, a shaft portion 45a of a cover mounting screw 45, which is a screw member, is inserted into a through hole 29a formed through the flange portion 29 of the cover 15 at a position corresponding to the boss portion 39, and the cover mounting screw 45 is inserted. The cover 15 is fastened and fixed to the case 12 by being screwed to the boss portion 39. A spring washer 46 and a flat washer 47 are interposed between the head 45 b of the cover mounting screw 45 and the flange portion 29 of the cover 15.

  That is, after applying the liquid or paste adhesive 44 in a series of seal grooves 35 including the outer peripheral groove 38a and the inner peripheral groove 38b, before the adhesive 35 is cured, the protruding edge on the cover 15 side. The cover 15 is immersed in the adhesive 44 and the cover 15 is fastened and fixed to the case 12 with the cover mounting screw 45, and the adhesive 54 is heated and cured in this state, whereby the cover 15 and the case 12 are bonded. A liquid-tight seal is formed between the two 12 and 15 while being bonded and fixed.

  More specifically, the portion of the adhesive 44 corresponding to the general portion 35a of the seal groove 35 and the outer peripheral groove portion 38a of each surrounding portion 38 has the tip end side of the protruding edge portion 30 on the cover 15 side around the entire circumference. On the other hand, the portion of the adhesive 44 corresponding to the inner circumferential groove 38b of each surrounding portion 38 is in close contact with the inner surface of the flange portion 29 of the cover 15 without a gap. As a result, between the stepped surface 43a formed by the boss portion main body 40 and the land portion 43 and the flange portion 29 on the cover 15 side, and between the boss portion main body 40 and the adhesive 44, A gap S <b> 2 isolated from the substrate housing space S <b> 1 of the housing 7 is formed. The gap S2 is configured such that the width dimension W of the surrounding portion 38 is substantially uniform in the longitudinal direction of the surrounding portion 38 and substantially the same as the general portion 35a excluding the surrounding portion 38. Thus, the variation in the application amount of the sealing material 44 to be described later is reduced, and is favorably ensured on the stepped surface 43a.

  The gap S2 and the external space of the housing 7 include the communication groove 42a, the radial gap G1 formed between the shaft portion 45a of the cover mounting screw 45 and the through hole 29a, and the cover mounting screw 45. Communicating with each other through an air passage 48 constituted by a radial gap G2 formed between the shaft 45a and the flat washer 47 and a circumferential gap G3 formed between both ends of the spring washer 46 in the circumferential direction. Yes.

  Therefore, according to the present embodiment, when heat is applied to the adhesive 44 to cure the adhesive 44, the air existing in the gap S2 is also heated and the air expands. Since the air thus discharged is discharged to the outside of the housing 7 through the air passage 48, the adhesive 44 does not peel off from the flange portion 29 of the cover 15 due to the pressure of the air in the gap S2, and the sealing performance Can be prevented.

  As a matter of course, even after the adhesive 44 is cured, the air in the substrate housing space S1 and the gap S2 may expand or contract due to a temperature change. 7, while air is supplied to and discharged from the external space of the housing 7, while the substrate receiving space S <b> 1 supplies and discharges air to and from the external space of the housing 7 through the breathing filter 32. The pressure difference between the two will be at least relaxed. Thereby, even after the adhesive 44 is cured, peeling of the sealing material from the lid body is suppressed, and a decrease in sealing performance can be suppressed.

  In addition, by forming the land portion 43 between the surrounding portion 38 of the seal groove 35 and the communication groove 42 a of the boss portion 39, the communication groove 42 a and the seal groove 35 are separated in the radial direction of the boss portion 39. Therefore, it is possible to prevent the communication groove 42a from being blocked by the adhesion of the adhesive 44, and to more reliably supply and discharge air into the gap S2.

  Further, the seal groove 35 is configured such that the width dimension W of the surrounding portion 38 is substantially uniform in the longitudinal direction of the surrounding portion 38 and is substantially the same as the general portion 35 a excluding the surrounding portion 38. Therefore, it is not necessary to positively change the coating amount of the sealing material 44 between the outer peripheral groove 38a and the inner peripheral groove 38b and between the surrounding portion 38 and the general portion 35a. As a result, the application amount of the sealing material 44 to the both portions 35a and 38 can be made constant, and as a result, the application workability of the sealing material 44 can be improved. At the same time, it is also used to improve the sealing performance of the sealing material 44 by reducing the variation in the coating amount (coating thickness). In other words, by making the application amount of the sealing material 44 to both the portions 35a and 38 constant, the application operation can be automated using, for example, a coating machine (not shown), and the number of work steps can be reduced. This can contribute to improving productivity and reducing manufacturing costs.

  Furthermore, as described above, by using an applicator for the application work of the seal material 44, the seal material 44 can be applied almost certainly along the seal groove 35. As a result, the seal material 44 is sealed into the seal groove. There is no fear that it will slightly deviate from 35 and adhere to, for example, the stepped surface 43a, and this also serves to suppress inconveniences that hinder the formation of the gap S2.

  As described above, in the above embodiment, the electronic control device according to the present invention is applied to the brake booster. However, the present invention is not limited to the configuration of the embodiment. The present invention can be applied to various devices such as a power steering device and an automatic transmission.

3. Motor controller (electronic controller)
7 ... Case 12 ... Case 15 ... Cover (lid)
16 ... Power module (circuit board)
17 ... Control module (circuit board)
29a ... Through-hole 35 ... Sealing groove 38 ... Surrounding part 39 ... Boss part 41 ... Screw hole 42 ... Seating surface 42a ... Communication groove 43a ... Stepped surface 44 ... Adhesive (sealant)
45 ... Cover mounting screw (screw member)
48 ... Air passage S2 ... Gap between boss and adhesive

Claims (3)

In an electronic control device in which a circuit board is housed in a housing composed of a case that opens toward one side and a lid that closes the opening of the case,
A boss projecting from the opening edge of the case toward the lid,
A through-hole formed in a position corresponding to the boss portion of the lid;
A screw member that is screwed into the boss while passing through the through hole, and fastens and fixes the case and the lid;
A seal groove that is formed along the opening edge of the case and has a surrounding portion that surrounds the outer peripheral side of the boss portion in a closed loop shape;
A seal material provided in the seal groove and sealing between the opening edge of the case and the lid;
An air passage communicating the gap between the boss portion and the sealing material and the external space of the housing;
An electronic control device comprising:   The boss part includes a screw hole into which the screw member is screwed, a seating surface on which the lid is seated, and a stepped surface formed at a predetermined interval between the lid and the boss portion. The electronic control device according to claim 1, wherein the gap is formed between the stepped surface and the lid.   While a radial gap is formed between the outer peripheral edge of the through hole and the screw member, a communication groove that communicates the radial gap and the gap is formed on the seating surface of the boss portion. 3. The electronic control device according to claim 1, wherein the radial gap and the communication groove function as a part of the air passage.

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