Accommodation device for electronic parts

An accommodation device of a water-proof casing has a casing body and a casing cover. A control unit is accommodated in an accommodation space formed in the accommodation device. An air breathing hole is formed in the casing cover for communicating the accommodation space to an outside of the accommodation device. A filter element is fixed to a bottom surface of a filter accommodation portion, which is formed on an outside surface of the casing cover, so as to close an open end of the air breathing hole. A filter cover is fixed to the casing cover so as to cover the filter element. A cover positioning portion is formed in the filter accommodation portion on the bottom surface, so that the filter cover can be easily and correctly positioned with respect to the casing cover.

CROSS REFERENCE TO RELATED APPLICATION

This application is based on Japanese Patent Application No. 2015-118375 filed on Jun. 11, 2015, the disclosure of which is incorporated herein by reference.

FIELD OF TECHNOLOGY

The present disclosure relates to an accommodation device for electronic parts and further relates to an electronic device having the accommodation device.

BACKGROUND

A water-proof housing for accommodating an electronic circuit board or the like is known in the art, for example, as disclosed in Japanese Patent Publication No. 2011-165748. According to the above prior art, a cover member is fixed to a housing for accommodating an electronic circuit board. An air ventilation through-hole is formed in the cover member. A filter element is attached to an outer surface of the cover member by a double-faced adhesive tape so as to cover the air ventilation through-hole. The filter element and the double-faced adhesive tape form an air breathing filter unit. A shielding member is further provided above the air breathing filter unit.

According to the above prior art, the shielding member of a plate shape is attached to the cover member by adhesive material at a position above the air breathing filter unit in order to protect the air breathing filter unit. According to the above prior art, there is no positioning means for the shielding member. It is, therefore, difficult to properly and easily assemble the shielding member to the cover member at a correct position.

SUMMARY OF THE DISCLOSURE

The present disclosure is made in view of the above problem. It is an object of the present disclosure to provide an accommodation device, to which a filter cover for protecting a filter member can be easily assembled. It is another object of the present disclosure to provide an electronic device for a vehicle having the above accommodation device.

According to one of features of the present disclosure, an accommodation device has a casing body, a casing cover, a filter accommodation portion, a filter element and a filter cover.

The casing body accommodates a protective component, for example, a control unit.

The casing cover is fixed to the casing body so as to form an accommodation space for accommodating the protective component. An air breathing hole is formed in the casing cover for communicating the accommodation space to an outside of the accommodation device.

The filter accommodation portion is formed on an outside surface of the casing cover. The filter accommodation portion has a bottom surface, wherein an outside end of the air breathing hole is opened at the bottom surface while an inside end of the air breathing hole is opened at an inside surface of the casing cover, that is, the accommodation space.

The filter element is fixed to the bottom surface of the filter accommodation portion for covering the outside end of the air breathing hole.

The filter cover is fixed to the casing cover for covering the filter element.

A cover positioning portion is formed in the filter accommodation portion of the casing cover for positioning the filter cover with respect to the casing cover.

According to the above feature of the present disclosure, it is possible to properly protect the filter element because the filter element is covered by the filter cover. In addition, since the cover positioning portion is formed in the recessed portion of the casing cover, it is possible to properly position the filter cover with respect to the casing cover. In other words, it becomes easier to assemble the filter cover to the casing cover.

DETAILED DESCRIPTION OF THE EMBODIMENTS

The present disclosure will be explained hereinafter by way of multiple embodiments and/or modifications with reference to the drawings. The same reference numerals are given to the same or similar structures and/or portions throughout the multiple embodiments and/or modifications in order to avoid repeated explanation.

First Embodiment

A first embodiment of the present disclosure will be explained with reference toFIGS. 1 to 10.

As shown inFIG. 1, a water-proof casing50, which is an accommodation device of the present disclosure, is applied to, for example, a driving device1for an electrical apparatus mounted in a vehicle. The driving device1is, for example, an electrical power steering device for the vehicle and usually mounted in an engine room of the vehicle.

The driving device1has an electric motor10, a control unit30and the water-proof casing50(the accommodation device50) for accommodating the control unit30. In the present disclosure, the control unit30corresponds to a protective component accommodated in the accommodation device50. In the driving device1, the control unit30is provided at one axial side of the electric motor10. In the present embodiment, the control unit30is provided on a rear side (an upper side inFIG. 1) of the electric motor10opposite to an output side (a lower side inFIG. 1) of the electric motor30. The driving device1of the present embodiment is a mechanical-and-electrical integrated device.

The electric motor10of the present embodiment is composed of a three-phase brush-less type electric motor. An outer frame of the electric motor10is composed of a cylindrical motor casing11, a front end frame12and a rear end frame13, wherein each of the front and the rear end frames12and13closes each axial end of the motor casing11. Although not shown in the drawings, a stator, a rotor, a rotating shaft rotating together with the rotor, and so on are accommodated in the motor casing11.

Multiple stator coils are wound on a stator core and each coil terminal extending from the respective stator coil is outwardly projected from the rear end frame13of the electric motor10. Power modules35(explained below) are provided on the rear side of the electric motor10and the coil terminals are electrically connected to the power modules35.

The control unit30is composed of a control circuit board (not shown), a power circuit board32, the power modules35, a heat sink40and so on.

Electronic parts and/or components (not shown) for a control system, such as, a micro-computer, pre-driver circuits and so on, are mounted to the control circuit board (not shown), which is provided between the heat sink40and the rear side of the electric motor10(on a front side of the heat sink40) and fixed to the heat sink40and/or the electric motor10by any well-known fixing means, such as screws, bolts or the like.

The power circuit board32, which is provided on a rear side of the heat sink40(opposite to the front side of the heat sink40facing the electric motor10), is likewise fixed to the heat sink40and/or the electric motor10by any well-known fixing means, such as screws, bolts or the like. Electrical parts and/or components (not shown) of a power system having relatively high current-carrying capacity, such as, a choke coil, a capacitor and so on, are mounted to the power circuit board32.

Each of the power modules35, which has switching elements for controlling electrical power supply to the stator coils, is fixed to the heat sink40so that heat can be transferred from the power module35to the heat sink40.

The power module35is arranged in such a way that it is parallel to an axial direction of the electric motor10, more exactly, in parallel to a virtual line outwardly extending from a center axis of the electric motor10. The power module35is electrically connected to the control circuit board and the power circuit board32. Motor terminals36are provided in the power module35so as to outwardly extend from the power circuit board32. The motor terminals36are electrically connected to the respective coil terminals (not shown) of the stator coils. In the present embodiments, two sets of the three-phase stator coils are provided. The power module35is provided for each set of the three-phase stator coils. Therefore, two power modules35are provided at both sides of the heat sink40, which are opposing to each other in a radial direction of the electric motor10.

In the present embodiment, each of the control circuit board, the power circuit board32, parts and/or components mounted to those of the circuit boards and the power modules35separately or collectively corresponds to electronic components included in the meaning of the protective component, which are accommodated in the water-proof casing50.

The heat sink40, which is made of such material having high heat conductivity, such as, aluminum or the like, supports the control circuit board, the power circuit board32and the power modules35. The heat sink40is fixed to the rear end frame13by any suitable fixing means (such as, screws, bolts and so on), in a condition that the above control circuit board, the power circuit board32and the power modules35are assembled to the heat sink40.

The water-proof casing50(the accommodation device50) has a connector casing51and a casing cover71.

The connector casing51is made of resin or the like in such a way that a first connector portion53, a second connector portion54and a main body portion55are integrally formed as one unit. The connector casing51is fixed to the rear end frame13by screws59. An O-ring (not shown) is provided between the connector casing51and the rear end frame13at such a portion, at which the connector casing51and the rear end frame13are in contact with each other. According to such a structure, extraneous material including water is prevented from entering an inside space formed by the connector casing51, the rear end frame13and the casing cover71via a gap between the connector casing51and the rear end frame13. The connector casing51is also referred to as a casing body51.

Each of the first and the second connector portions53and54is integrally formed with the main body portion55so as to outwardly protrude from the main body portion55in the radial direction. The electronic components accommodated in the water-proof casing50are electrically connected to a battery, CAN (Controller Area Network), various kinds of sensors and so on via the first and the second connector portions53and54.

The main body portion55is formed in a cylindrical shape. An adhesion groove56is formed on a rear side of the main body portion55, that is, on a side of the main body portion55opposite to the electric motor10.

The casing cover71is formed in a cylindrical shape having a closed top end. The casing cover71is provided at the rear side of the main body portion55(that is, a rear side of the driving device1opposite to the electric motor10). The casing cover71has a top end portion711and a peripheral wall portion712. A fitting portion713is formed at a front side of the peripheral wall portion712(at a lower side of the peripheral wall portion712inFIG. 1). The fitting portion713is inserted into the adhesion groove56of the connector casing51and fixed to the connector casing51, for example, by adhesive material. According to such a structure, the extraneous material (for example, water) is prevented from entering the inside space formed by the connector casing51, the rear end frame13and the casing cover71via a gap between the connector casing51and the casing cover71.

In the present embodiment, the control unit30(including the power circuit board32, the power modules35and so on) is accommodated in an accommodation space49, which corresponds to the inside space formed by the connector casing51, the rear end frame13and the casing cover71.

As shown inFIGS. 2 and 3, a recessed portion70is formed in the top end portion711of the casing cover71as a filter accommodation portion. A filter fixing surface73is formed at a bottom of the recessed portion70. The filter fixing surface73is also referred to as a bottom surface73of the recessed portion70. The filter fixing surface73is formed at a position, which is recessed in the axial direction to the electric motor10from an axial end surface715of the top end portion711. An air breathing hole74is formed in the top end portion711at a center of the recessed portion70, so that an outside end (an upper-side end) of the air breathing hole74is opened at the filter fixing surface73, while an inside end (a lower-side end; not shown in the drawings) is opened at a front surface of the casing cover71. As above, the air breathing hole74communicates the accommodation space49to an outside of the water-proof casing50of the driving device1. In the present embodiment, a cross section of the air breathing hole74is formed in a circular shape.

Four columnar portions75are provided in the recessed portion70on the filter fixing surface73at a radial outside of the air breathing hole74. Each of the columnar portions75has a filter positioning portion76formed at a lower end of the columnar portion75and extending in a radial inward direction from the lower end toward the air breathing hole74. The columnar portion75has a cover positioning portion77formed at a radial outside of the filter positioning portion76. A height of the cover positioning portion77in the axial direction is larger than that of the filter positioning portion76.

A peripheral wall portion78is formed at the recessed portion70at a radial-outside of the columnar portions75. In the present embodiment, the peripheral wall portion78is formed in a circular shape, so that the peripheral wall portion78continuously extends in its circumferential direction. The peripheral wall portion78is outwardly projected in the axial direction (in an upward direction) from the top end portion711. The peripheral wall portion78is separated from each of the columnar portions75in the radial direction.

A filter element80, which is made of such material having water-proof property and ventilation characteristic, is formed in a disc shape. The filter element80is attached to the filter fixing surface73(on a side opposite to the electric motor10) so as to cover the outside end of the air breathing hole74. The filter element80is thermally adhered to the casing cover71. According to the above structure, the accommodation space49has water-proof property and it is possible to suppress a pressure change in the accommodation space49, which may be caused by a temperature change in the driving device1.

The filter element80has a shape (a size) corresponding to a filter fixing area defined in an inside of the filter positioning portions76. More exactly, the filter element80is slightly smaller than the filter fixing area in the radial direction. According to such a structure, the filter element80can be properly and easily positioned by the filter positioning portions76with respect to the recessed portion70.

As shown inFIGS. 1 to 10, a filter cover81is arranged at a position above the filter element80and inside of the peripheral wall portion78so as to cover the filter element80.

As shown inFIGS. 8 to 10, the filter cover81, which is made of resin, has a flat plate portion82and multiple leg portions85(four leg portions85in the present embodiment).FIG. 8shows a top plane of the filter cover81, that is, a rear side plane opposite to the electric motor10when it is assembled to the casing cover71. More exactly,FIG. 8is a view when viewed the filter cover81in a direction indicated by an arrow VIII inFIG. 10.FIG. 9shows a front side of the filter cover81, that is,FIG. 9is a view of the filter cover81on the side to the electric motor10when it is assembled to the casing cover71. More exactly,FIG. 9is a view when viewed the filter cover81in a direction indicated by an arrow IX inFIG. 10.

Multiple (four) notched portions83are formed at an outer periphery of the flat plate portion82. Each of the notched portions83has a shape corresponding to that of the cover positioning portion77. A number of the notched portions83corresponds to that of the cover positioning portions77. The filter cover81is arranged at a position in such a manner that each of the notched portions83is fitted to the respective cover positioning portion77. According to such a structure, the filter cover81can be easily and correctly positioned to the filter element80and the air breathing hole74. In the present embodiment, fitting portions between the filter cover81and the cover positioning portions77are thermally adhered, so that the filter cover81is firmly fixed to the casing cover71.

As shown inFIG. 4, the filter cover81is separated from the peripheral wall portion78in the radial direction, in a condition that the filter cover81is fixed to the casing cover71.

Each of the leg portions85is formed at the outer periphery of the flat plate portion82, at such portions at which the notched portions83are not formed. Each of the leg portions85extends in the axial direction (a thickness direction of the flat plate portion82). When the filter cover81is fixed to the casing cover71, a forward end of each leg portion85is in contact with the filter fixing surface73, as shown inFIG. 6.

Each of the notched portions83is separated from the neighboring leg portions85in the circumferential direction. As shown inFIG. 4, when the filter cover81is fixed to the casing cover71, air ventilation portions86are formed between each of the columnar portions75and each of the leg portions85in the circumferential direction. As shown inFIGS. 4 to 7, positions for the cover positioning portions77(FIG. 5) or positions of the leg portions85(FIG. 6) and positions of the air ventilation portions86are alternately arranged along the outer periphery of the filter cover81, when the filter cover81is fixed to the casing cover71.

In addition, since the filter cover81is separated from the peripheral wall portion78in the radial direction, an inside space formed inside of the filter cover81is communicated to the outside of the driving device1via the air ventilation portions86. Accordingly, it is possible to properly control the inside pressure of the driving device1.

Each ofFIGS. 5 to 7is a cross sectional view corresponding to respective cross sections inFIG. 4. In each ofFIGS. 5 to 7, the filter cover81and its related portions are schematically enlarged.

As shown inFIG. 6, a height “H1” of the peripheral wall portion78from the filter fixing surface73is larger than a height “H2” of the filter cover81from the filter fixing surface73. In other words, the peripheral wall portion78is taller than the filter cover81by a height “d”. Therefore, a top end surface815of the filter cover81is located at a position, which is lower than a top end surface785of the peripheral wall portion78, when the filter cover81is fixed to the casing cover71. Namely, the top end surface815is recessed from the top end surface785in the axial direction to the electric motor10.

Since the driving device1is located in the engine room of the vehicle, a relatively large external force may be applied to the filter cover81, for example, by collision of a flying stone during a running of the vehicle. In a case that the filter cover81is fixed to the casing cover71by the adhesive material, strength poverty may occur depending on the external force to be applied to the filter cover81. According to the present embodiment, therefore, the filter cover81is thermally adhered to the casing cover71by a thermal welding process, in order to increase adhesion strength when compared with the case of the adhesive material. In addition, the height of the peripheral wall portion78is made to be larger than that of the filter cover81, so that the flying stone is not likely to directly collide against the filter cover81. According to the above structure, it is possible to prevent a situation that the filter cover81drops out of the casing cover71and the filter element80is thereby exposed to the outside of the driving device1.

As explained above, the water-proof casing50(the accommodation device) of the present embodiment has the connector casing51, the casing cover71, the filter element80and the filter cover81.

The control unit30(the protective component) is accommodated in the accommodation space49formed by the connecter casing51and the casing cover71. The air breathing hole74is formed in the casing cover71for communicating the accommodation space49with the outside of the driving device1. The casing cover71is fixed to the connector casing51.

The filter element80covers the outside end of the air breathing hole74, that is, the rear side of the casing cover71opposite to the accommodation space49. The filter element80is attached to the casing cover71. The filter cover81, which covers the filter element80on the side of the casing cover71opposite to the accommodation space49, is fixed to the casing cover71.

The cover positioning portions77are formed on the casing cover71for positioning the filter cover81to the casing cover71.

In the present embodiment, the filter element80, which is made of the material having the water-proof property and the ventilation characteristic, covers the air breathing hole74so as to not only prevent the water from entering the inside of the water-proof casing50but also properly control the inside pressure of the water-proof casing50. Since the filter element80is covered by the filter cover81, it is possible to properly protect the filter element80. In addition, the cover positioning portions77are formed in the recessed portion70of the casing cover71in order to correctly position the filter cover81with respect to the casing cover71. It is, therefore, possible to easily assemble the filter cover81to the casing cover71.

The peripheral wall portion78of the recessed portion70is formed on the casing cover71at the radial outside of the filter cover81. The peripheral wall portion78continuously surrounds the filter element80and the filter cover81in the circumferential direction. The height “H1” of the peripheral wall portion78from the filter fixing surface73is made to be larger than the height “H2” of the filter cover81from the filter fixing surface73. Accordingly, the extraneous material, such as, the flying stone, cannot easily and directly collide against the filter cover81.

The filter positioning portions76are formed in the recessed portion70of the casing cover71. It is, therefore, possible to properly position the filter element80with respect to the casing cover71.

The filter positioning portion76is integrally formed with the cover positioning portion77. It is, therefore, possible to form the filter positioning portion76and the cover positioning portion77in a relatively small area. In other words, a size of the driving device1can be made smaller.

The filter cover81has the flat plate portion82and the leg portions85. The notched portions83, each of which is fitted to the respective cover positioning portion77, are formed in the flat plate portion82. Each of the leg portions85is projected in the axial direction from the flat plate portion82and its forward end is brought into contact with the casing cover71.

The air ventilation portions86are formed between each of the cover positioning portions77and each of the leg portions85, in the condition that the filter cover81is fixed to the casing cover71.

According to the above structure, it is possible to properly control the inside pressure of the water-proof casing50.

The filter cover81is thermally adhered to the casing cover71. The filter element80is likewise thermally adhered to the casing cover71. According to the above structure, it is possible to increase peeling strength, when compared with the case in which the filter element80as well as the filter cover81is fixed to the casing cover71by the adhesive material.

The driving device1of the present embodiment has the water-proof casing50(the accommodation device) and the control unit30(the protective component), which includes the power circuit board32and the power modules35as the electronic components. According to the present embodiment, it is possible to properly protect the control unit30(the protective component) from the extraneous material.

Second Embodiment

A driving device2according to a second embodiment of the present disclosure is shown inFIG. 11.

A casing cover171of the driving device2of the second embodiment differs from that of the first embodiment. More exactly, a shape of a peripheral wall portion172is different from that of the first embodiment.

As shown inFIG. 11, which is a view showing a rear side of the driving device2when viewed it from an opposite side to the electric motor10(not shown inFIG. 11), the peripheral wall portion172is formed in a pentagonal shape. The peripheral wall portion172may be formed in any other polygonal shape, such as, a rectangular shape, a hexagonal shape and so on.

The same advantages to those of the first embodiment can be also obtained in the second embodiment.

Third Embodiment

A driving device3according to a third embodiment of the present disclosure is shown inFIG. 12.

A casing cover174of the driving device3of the third embodiment differs from that of the first embodiment. More exactly, a shape of a peripheral wall portion175is different from that of the first embodiment.

As shown inFIG. 12, which is a view showing a rear side of the driving device3when viewed it from an opposite side to the electric motor10(not shown inFIG. 12), the peripheral wall portion175is formed in a circular shape in the same manner to the first embodiment. However, the peripheral wall portion175of the present embodiment is composed of a first wall portion176and a second wall portion177. A pair of grooves178is formed between the first and the second wall portions176and177in its circumferential direction. In the first embodiment, the peripheral wall portion78continuously surrounds the recessed portion70for the filter element80, the filter cover81and the cover positioning portions77. In the third embodiment, however, the first and the second wall portions176and177intermittently surround the recessed portion70for the filter element80, the filter cover81and the cover positioning portions77. According to the above structure, it is possible to increase a productivity of a step for assembling the filter element80and the filter cover81to the casing cover71.

In addition, the same advantages to those of the first embodiment can be also obtained in the third embodiment.

Further Modifications

In the above embodiments, the recessed portion70is formed in the rear side of the casing cover71(171,174), that is, the axial side of the driving device1(2,3) opposite to the electric motor10. However, the recessed portion70may be formed in the casing cover71(171,174) at any other portion, such as, the peripheral wall portion712of the casing cover71(171,174), so long as it is possible to communicate the accommodation space49to the outside of the driving device1(2,3) via the air breathing hole74.

In the above embodiments, the recessed portion70is formed in the cylindrical shape. However, the recessed portion70may be formed in any other shape than the cylindrical shape.

In the above embodiments, the peripheral wall portion78of the recessed portion70is made to be taller than the top end surface715of the casing cover71(171,174). The height of the peripheral wall portion78may be made to be the same level to that of the top end surface715of the casing cover71(171,174), so long as the peripheral wall portion78is taller than the filter cover81. In this case, the top end surface715of the casing cover71(171,174) works itself as the peripheral wall portion for the recessed portion70. In other words, the peripheral wall portion78outwardly projecting is not necessarily formed for the recessed portion70.

In the above embodiments, the recessed portion70is formed as the filter accommodation portion. However, the present disclosure is not limited to the recessed portion. For example, the filter accommodation portion may be formed in such a manner that the filter fixing surface73(that is, the bottom surface of the filter accommodation portion) is formed on the same level to that of the axial end surface715of the casing cover71and the peripheral wall portion78is upwardly projected from the bottom surface. Alternatively, the bottom surface of the filter accommodation portion may be formed at a position elevated in the upward direction from the axial end surface715of the casing cover71.

In the third embodiment shown inFIG. 12, the pair of the grooves178is formed between the first and the second wall portions176and177in the circumferential direction. The number as well as the shape of the grooves178is not limited to those of the third embodiment shown inFIG. 12, so long as the filter cover81and the filter element80can be protected from the extraneous material, such as the flying stone.

In the second embodiment shown inFIG. 11, the peripheral wall portion172is formed in the polygonal shape. The grooves178of the third embodiment may be formed at edges of the polygonal shape. In addition, the peripheral wall portion172for the recessed portion70may be formed in any other forms than the circular shape and the polygonal shape.

In the above embodiments, the cover positioning portion77and the filter positioning portion76are integrally formed as one unit. However, the cover positioning portion77may be formed as a separate member from the filter positioning portion76. Alternatively, the cover positioning portion77may not be necessarily formed.

In the above embodiments, four cover positioning portions77are formed. A number of the cover positioning portions77is not limited to four. The shape of the cover positioning portion77is not limited to the shape shown in the embodiments, for example, shown inFIG. 2, so long as it is possible to correctly position the filter cover81in the recessed portion70. In the same manner, the number and the shape of the filter positioning portion76are not limited to those of the embodiments, for example, shown inFIG. 2.

In the above embodiments, the filter element80is thermally adhered to the casing cover71. However, the filter element80may be fixed to the casing cover71by any other methods than the thermal adhesion.

In the above embodiments, the filter cover81is thermally adhered to the casing cover71. However, the filter cover81may be fixed to the casing cover71by any other methods, for example, ultrasonic adhesion. In addition, the filter cover81may be fixed to the casing cover71by any other method than the adhesion, for example, by adhesive material.

In the above embodiments, the connector casing51, to which the first and the second connector portions53and54are integrally formed, is formed as the casing body for accommodating the control unit30. However, any other part or portion of the driving device1may be used as the casing body for accommodating the protective component (the control unit30).

In the above embodiments, the connector casing51is formed in the cylindrical shape and one axial end thereof (on the side to the electric motor10) is closed by the rear end frame13of the electric motor10. However, the casing body for accommodating the protective component may be formed in a cup shape having a closed bottom on the side to the electric motor10and having an open end on the side to the casing cover71.

In the above embodiments, the protective component is composed of the control unit30having the control circuit board, the power circuit board32and the power modules35. However, the protective component may include any other electronic or non-electronic parts, so long as they are accommodated in the accommodation space49.

In the above embodiments, the accommodation device (the water-proof casing50) is applied to the driving device1, in which the electric motor10and the control unit30are integrally assembled to each other. However, the accommodation device may be applied to any other electronic devices other than the driving device1(2,3) of the above embodiments.

In the above embodiments, the driving device1(2,3) is applied to the electric power steering device for the vehicle, which is usually located in the engine room. The driving device1(2,3) may be located in any other places than the engine room. The driving device may be applied to any other electronic devices for the vehicle or any other electronic devices for use of non-automotive purpose.

The present disclosure is not limited to the above embodiments and/or modifications but can be further modified in various manners without departing from a spirit of the present disclosure.