JP2008055981A - Electronic control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To simplify a filter fixing structure of a ventilation hole for breathing the inside and the outside of a case of an electronic control device, and to suppress peeling of a filter by a jet stream or the like of high pressure washing. <P>SOLUTION: In the electronic control device provided with the ventilation hole 22c for breathing the inside and the outside on the case 20 for storing a print wiring board 10 mounted with an electronic part and a connector, a filter membrane 50 is stuck to a sheet 60 provided with a plurality of fine holes 61 so as to cover the ventilation hole 22c and having an adhesion part, and the filter membrane 50 is fixed by the sheet 60. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electronic control device that controls an automobile engine and the like, and more particularly to a filter fixing structure for ensuring air permeability between the inside and the outside of an electronic control device.

  In general, an electronic control device that controls an automobile engine or the like is configured by housing a printed wiring board on which an electronic component constituting an electronic circuit that achieves a function as an electronic control device is mounted in a case with a waterproof seal. Is done. The case is provided with a vent hole to obtain air permeability between the inside and the outside.

  In particular, when the electronic control unit is provided in the engine room, there is a risk of water splashing on the electronic control unit. In such a case, in order to prevent water from entering the case of the electronic control unit, Is fitted with a filter.

  Conventionally, in such a filter fixing structure of an electronic control device, a hole or a cylinder is provided in a partial region of the case, the filter membrane is fixed by resin welding, and the filter membrane is formed by a cap fixed to the case by a snap fit or the like. Is protecting.

  Moreover, the technique described in patent document 1 is known as another fixing structure. In the technique described in Patent Document 1, a filter is configured by a filter film attached to the outside of the case so as to cover a plurality of air holes communicating the inside and the outside of the case.

  Furthermore, as another technique, as described in Patent Document 2, there is a structure in which a filter membrane is pressed with an annular filter pressing plate in which a screw insertion hole is formed, and the filter pressing plate is screwed to the case with a screw. Are known.

JP-A-2005-2443829 JP 2000-138469 A

  As described above, in the filter fixing structure in which the filter film is welded to the resin, it is necessary to use resin for the filter housing, and the material is limited. Moreover, since a cap and a snap fit are provided, the shape becomes complicated and the moldability deteriorates. Furthermore, since the filter membrane is indirectly fixed with an O-ring or the like interposed therebetween, it is difficult to ensure airtightness.

  In the technique disclosed in Patent Document 1, an adhesive portion is provided on the filter film itself in order to fix the filter film to the case. The adhesive portion is required to have an adhesive force that can withstand peeling of the filter membrane due to a jet of high-pressure washing or the like. For this reason, it is necessary to enlarge the bonding portion to some extent, and it is difficult to fix the filter membrane with high accuracy when mounting. Further, since the filter membrane is directly exposed to the outside, there is a problem that it is easily damaged by an external load. Although the outer wall is provided, it is only temporary, and the filter membrane cannot be sufficiently protected. Furthermore, it is assumed that water, mud, and the like stop around the outer wall.

  In the technique disclosed in Patent Document 2, a filter holding plate is required, and this must be fixed with screws, which increases the number of parts, increases the time required for assembly, and increases costs. There's a problem.

  In order to solve the above-described problems in the prior art, the present invention provides a printed wiring board on which electronic components are mounted, a case that contains the printed wiring board and has ventilation holes for venting inside and outside of the printed wiring board. An electronic control device having a filter membrane covering a pore, wherein the filter membrane is fixed to the case by a sheet having a plurality of minute holes provided so as to cover the vent hole at a position corresponding to the vent hole. It is said.

  It is possible to simplify the filter fixing structure of the air holes for breathing the inside and outside of the case of the electronic control device, and it is possible to suppress the peeling of the filter due to the high pressure washing jet or the like.

  Hereinafter, the present invention will be specifically described based on examples. In addition, this invention is not limited to a following example, In the range of the summary described in the claim, it can change suitably.

  FIG. 1 is an exploded perspective view showing the configuration of an embodiment of an electronic control device according to the present invention.

  The electronic control device 1 is a control device that is mounted, for example, in an engine room of an automobile and controls at least a part of various mechanical elements of the automobile such as an engine and various actuators. The electronic control device 1 includes a printed wiring board 10 on which electronic components that constitute an electronic circuit for realizing various controls are mounted, and a case 20 that houses the printed wiring board 10. In the figure, the connector terminals are not shown.

  A connector 12 for exchanging signals with the outside is connected to the printed wiring board 10. The connector 12 is attached to the opening of the case 20, and a harness is connected when the vehicle is mounted.

  The case 20 includes a case main body 21 serving as a base, and a cover 22 that seals the opening of the case main body 21 and forms a space for accommodating the printed wiring board 10 together with the case main body 21. Sealing material 31 is waterproof between the opening edge portion 21 a of the case body 21 and the inner surface of the peripheral edge portion 22 b of the cover 22 and between the connector lower surface portion 12 c and the front wall portion upper surface 21 b of the case body 21. . Further, the space between the connector opening inner surface 22 a of the cover 22 and the side surface portion 12 b and the upper surface portion 12 a of the connector is waterproofed by a sealing material 30. The case main body 21 and the cover 22 are fixed by screws 40.

  A ventilation hole 22c is provided on the upper surface of the cover 22, and ventilation between the inside and the outside of the electronic control device 1 is ensured. The ventilation hole 22c is covered with a filter film 50 from the outside of the cover 22, and the filter film 50 is fixed to the cover 22 by an adhesive sheet 60 provided with a plurality of minute hole portions 61. The cover 22 is formed by press, casting, injection molding with resin, or the like.

  FIG. 2 is a cross-sectional view of the main part showing the filter protection structure of the electronic control device according to the present invention.

  The filter membrane 50 is disposed so as to cover the vent hole 22 c, is covered with the sheet 60 from above, and is fixed to the cover 22. The filter membrane 50 has a water resistance strength enough to withstand a jet such as high-pressure washing. The filter membrane 50 is made of a member made of a material that has air permeability but inhibits passage of water or the like.

  The minute hole portion 61 provided in the sheet 60 is provided so as to be located at the position of the air hole 22 c, and the inside and the outside of the electronic control device 1 through the air hole 22 c, the filter film 50, and the minute hole portion 61. Air is allowed in and out of the air. On the other hand, since the vent hole 22c is covered with the filter film 50, water does not enter the electronic control device 1 from the outside.

  As the sheet 60, it is possible to substitute a sheet used for the traceability such as a name plate or the identification of the electronic control device 1. In this way, the number of parts can be reduced by using a sheet such as a name plate. In this case, it is desirable that the minute hole portion 61 is composed of a plurality of minute holes that are large enough to distinguish characters written on the sheet 60 and to breathe inside and outside the case 20.

  FIG. 3 is a top view of the main part showing the filter fixing structure of the electronic control unit.

  FIG. 3A shows a fixing structure in which a rectangular filter membrane 50a having a side length larger than the diameter of the vent hole 22c is attached as a filter membrane 50 to the circular vent hole 22c. Show. FIG. 3B shows a fixed structure in which a circular filter membrane 50b having a radius larger than the radius of the vent hole 22c is attached as a filter membrane 50 to the circular vent hole 22c.

  As described above, the shape of the filter membrane 50 may be rectangular or circular as long as it can be formed in a shape larger than the shape of the vent hole 22c of the cover 22 and smaller than the shape of the sheet 60 to be attached. It may have an arbitrary shape such as a circular shape.

  FIG. 3C shows a filter membrane fixing structure in which an elliptical filter membrane 50c larger than the vent hole 22c ′ is attached to the oval vent hole 22c ′. As described above, the shape of the filter membrane can be freely adjusted to the size of the case 20 and the shape of the vent hole communicating between the inside and the outside.

  In this way, the filter membrane has a filter fixing structure that matches the shape of the case and vent holes, and the shape of the adhesive sheet that covers it has a degree of freedom, so that it is waterproof and reliable. Improvement can be secured.

  According to the embodiment described above, the filter membrane is attached to the adhesive sheet provided with a plurality of micro hole portions, and the air holes provided in the cover are closed, so that the water resistance is reduced in a simplified shape. Sex can be obtained. Further, the filter film is not directly exposed to the outside, and the filter film is protected by the sheet. Furthermore, peeling of the filter due to a high-pressure washing jet or the like can be suppressed, and improvement in waterproofness and reliability can be ensured.

  FIG. 4 is a cross-sectional view of the main part showing the filter fixing structure in the second embodiment of the electronic control apparatus according to the present invention. In the present embodiment, the configuration other than the filter fixing structure described below will be described as having the same configuration as the first embodiment.

In the present embodiment, a recess 22d having substantially the same shape as the contact surface of the filter film 50 to the cover 22 and deeper than the thickness of the filter film 50 is provided on the outer surface side of the cover 22 and the periphery of the vent hole 22c. The filter membrane 50 is attached so as to be fitted into the recess 22d.

  With such a fixing structure, the filter film 50 can be easily positioned at the time of manufacture, and can be accurately attached by an automatic machine.

  FIG. 5 is a cross-sectional view of the main part showing the filter fixing structure in the third embodiment of the electronic control unit according to the present invention. In this embodiment, the configuration other than the filter fixing structure described below will be described as having the same configuration as that of the first embodiment.

In the present embodiment, a concave portion 22 e that matches the shape of the sheet 60 is provided on the outer surface side of the cover 22 and on the attachment position of the sheet 60 that fixes the filter film 50. As in the second embodiment, a recess 22d having substantially the same shape as the contact surface of the filter film 50 with the cover 22 and deeper than the thickness of the filter film 50 is provided in the recess 22e and the periphery of the vent hole 22c. It is done. The filter film 50 is attached so as to be fitted into the recess 22d, and is covered with a sheet 60 attached to the recess 22e.

  By adopting such a fixed structure, it is possible to prevent a jet of high-pressure cleaning or the like from being directly applied to the end portion 60a of the sheet 60, it is possible to suppress peeling of the filter film 50 due to high-pressure cleaning or the like, and more waterproof. Improvement in reliability and reliability.

  According to the embodiment described above, it is possible to simplify the filter fixing structure of the air holes provided in the cover of the electronic control device and to reduce the number of parts. In addition, the filter film can be protected because the filter film is not directly exposed to the outside while the filter film is prevented from being peeled off by a high-pressure cleaning jet or the like.

1 is an exploded perspective view of an electronic control apparatus according to a first embodiment of the present invention. It is principal part sectional drawing which shows the filter fixing structure in a 1st Example. It is a principal part top view of the filter fixing structure of an electronic control unit. It is principal part sectional drawing which shows the filter fixing structure in a 2nd Example. It is principal part sectional drawing which shows the filter fixing structure in a 3rd Example.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Electronic control apparatus, 10 ... Printed wiring board, 12 ... Connector, 20 ... Case, 21 ... Case main body, 22 ... Cover, 22c ... Air hole, 22d ... Recessed part (for filter attachment),
22e ... concave portions (for attaching a sheet), 30, 31 ... sealing material, 50 ... filter membrane, 60 ... sheet, 61 ... minute hole.

Claims (4)

  An electronic control device comprising: a printed wiring board on which an electronic component is mounted; a case including a vent hole for accommodating the printed wiring board and venting the inside and outside of the printed wiring board; and a filter film covering the vent hole. An electronic control device, wherein the membrane is fixed to the case by a sheet-like member having a plurality of minute holes provided so as to cover the vent hole at a position corresponding to the vent hole.   The electronic control device according to claim 1, wherein the filter film is larger than the vent hole and smaller than the sheet-like member.   3. The electronic control device according to claim 1, wherein a recess deeper than the thickness of the filter film is provided at a peripheral edge of the vent hole, and the filter film is disposed in the recess.   The electronic control device according to claim 1, wherein the sheet-like member is attached to a recess provided in a substantially same shape as the sheet-like member on a periphery of the vent hole.

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