PROTECTION STRUCTURE FOR FUEL PUMP CONNECTION PART

A protection structure for the fuel pump connection part includes a top plate 20 that has fuel pump connection parts 23, 25, and a cover member 30 that covers the top plate 20 and the fuel pump connection parts 23, 25. The cover member 30 includes a top plate cover part 31, hole parts 39, 41, and connection-part cover parts 45, 55. The top plate cover part 31 and the connection-part cover parts 45, 55 are integrally formed. The connection-part cover parts 45, 55 includes movable parts 47, 57 that move with respect to the top plate cover part 31, and the fuel pump connection parts 23, 25 are exposed in a state where the movable parts 47, 57 have moved in a separating direction from a front surface side of the top plate cover part 31.

TECHNICAL FIELD

The present invention relates to a protection structure for protecting a fuel pump connection part of a connection member connected to a fuel pump disposed in a fuel tank via the fuel pump connection part.

BACKGROUND ART

To a fuel pump disposed inside a fuel tank of a vehicle are connected connection members such as a tube that supplies a fuel to an internal combustion engine and wiring for supplying electric power to the fuel pump. These are connected to the fuel pump via the fuel pump connection part provided on a top plate covering an opening part of the fuel tank.

The above-described top plate and fuel pump connection part are often formed of resin. When a liquid containing a strong acid, such as a vehicle cleaning liquid, a rust removing agent, or a brake cleaner, adheres to these, the resin may be deteriorated. Therefore, it is conceivable to cover the top plate and the fuel pump connection part with an acid-resistant cover.

For example, Patent Literature 1 below describes a fuel supply device including: an attachment part that covers an opening part formed in an upper part of a tank and has a fuel discharge pipe and an electric connector disposed; and a cover that has a substantially dome shape and has a flange part formed on four sides of the cover. This cover is attached to the attachment part via a plurality of fitting protruding parts to cover the electric connector.

CITATION LIST

Patent Literature

Patent Literature 1: JP 2007-303347 A

SUMMARY OF INVENTION

Technical Problem

While in the invention of Patent Literature 1, only the electric connector is covered with the cover, it is desirable that the top plate and a connection pipe other than the electric connector are also covered with the cover.

However, in a case where in order to cover the connection part, an integral cover that covers the top plate and the connection part is to be attached after the connector is connected, it is necessary to attach the cover so as to avoid the connected connector and the like, and the attachment of the cover is complicated. Moreover, when a cover that covers the top plate before connection and a cover that covers the connection part after connection are separately prepared, a number of parts and a number of processes increase, and in this case, attachment of the covers is also complicated.

Furthermore, since the covers that covers each of the members is a separate body, a gap is generated between the covers. Therefore, there is a risk that from the gap, a liquid such as a vehicle cleaning liquid flows into, for example, between the cover and the top plate.

Therefore, an object of the present invention is to provide a protection structure for a fuel pump connection part that enables a cover member to be easily attached to a top plate or the fuel pump connection part, can protect the fuel pump connection part, and can suppress inflow of liquid.

Solution to Problem

In order to achieve the above object, the present invention provides a protection structure for protecting a fuel pump connection part of a connection member connected to a fuel pump disposed inside a fuel tank via the fuel pump connection part, the protection structure including: a top plate that covers an opening part of the fuel tank and includes the fuel pump connection part; and a cover member that covers the top plate and the fuel pump connection part, wherein the cover member includes a top plate cover part that covers the top plate, a hole part that is formed in this top plate cover part and through which the fuel pump connection part protrudes, and a connection-part cover part that extends from this hole part so as to cover the fuel pump connection part and the connection member connected to the fuel pump connection part, the top plate cover part and the connection-part cover part are integrally formed, and the connection-part cover part includes a movable part movable in a separating direction and an approaching direction with respect to a front surface side of the top plate cover part, and the fuel pump connection part is exposed in a state where this movable part has moved in the separating direction from the front surface side of the top plate cover part.

According to the above invention, after the cover member is attached and covers the top plate and the fuel pump connection part in a state where the fuel pump connection part protrudes from the hole part of the cover member, the movable part of the connection-part cover part is moved in the separating direction from the front surface side of the top plate cover part to expose the fuel pump connection part, which makes it possible to connect the connection member to the fuel pump connection part. Therefore, the cover member can be easily attached as compared with a case where the top plate cover part and the connection-part cover part are separate bodies and are separately attached.

Moreover, after the connection member is connected to the fuel pump connection part, the movable part is moved in the approaching direction with respect to the front surface side of the top plate cover part, which makes it possible to cover the fuel pump connection part and the connection member with the connection-part cover part. Therefore, the fuel pump connection part can be protected, and inflow of a liquid such as a cleaning liquid can be suppressed.

In the protection structure for the fuel pump connection part of the present invention, it is preferable that a wall part having a height higher than a height of a front surface of the top plate cover part is erected on a front-side peripheral edge of the hole part.

According to the above aspect, since the wall part having a height higher than the height of the front surface of the top plate cover part is erected on the front-side peripheral edge of the hole part, even if liquid attempts to flow into the hole part from a gap between the movable part and the top plate cover part, the liquid can be blocked by the wall part, so that the inflow of the liquid into the hole part can be suppressed.

In the protection structure for the fuel pump connection part of the present invention, it is preferable that the connection-part cover part includes a fixed part fixed to the top plate cover part, and a fragile part having a lower rigidity than the fixed part and the movable part is provided between the fixed part and the movable part.

According to this aspect, when the movable part is moved in the separating direction from the front surface side of the top plate cover part, the movable part can be moved with respect to the fixed part via the fragile part having a lower rigidity, the movable part can be easily moved, and the connection workability of the connection member with respect to the fuel pump connection part can be enhanced.

In the protection structure for the fuel pump connection part of the present invention, it is preferable that at least the movable part is formed of an elastic material. According to this aspect, the movable part can be moved in the separating direction from the front surface side of the top cover part so as to be turned up by using elasticity, and the fuel pump connection part can be easily exposed.

In the protection structure for the fuel pump connection part of the present invention, it is preferable that the top plate cover part is disposed with a gap interposed with respect to the top plate, and a rib extending toward the top plate and abutting on a front surface side of the top plate is provided on a back surface side of the top plate cover part and in a vicinity of the wall part.

According to this aspect, since the rib extending toward the top plate and abutting on the front side of the top plate is provided in the vicinity of the wall part on the back side of the top plate cover part, even if the vicinity of the wall part is pressed by an external force or the like, the rib abuts on the front surface side of the top plate, which makes it possible to suppress the deformation of the wall part by receiving an external force or the like, and more surely suppress the inflow of liquid into the hole part.

Advantageous Effects of Invention

According to the present invention, after the cover member is attached to the top plate, the movable part of the connection-part cover part is moved in the separating direction from the front surface side of the top plate cover part to expose the fuel pump connection part, which makes it possible to connect the connection member to the fuel pump connection part. Therefore, the cover member can be easily attached as compared with the case where the top plate cover part and the connection part cover part are separate bodies. Moreover, after the connection member is connected to the fuel pump connection part, the movable part is moved to the front surface side of the top plate cover part, which makes it possible to protect the fuel pump connection part and suppress inflow of a liquid such as a cleaning liquid can be suppressed.

DESCRIPTION OF EMBODIMENTS

Hereinafter, one embodiment of a protection structure for a fuel pump attachment part according to the present invention will be described with reference to the drawings.

As illustrated inFIG.4, a fuel pump10for feeding fuel to an internal combustion engine or the like is disposed inside a fuel tank1having a predetermined shape. An opening part5having a predetermined shape is formed in an upper wall of the fuel tank1. A top plate20is attached to this opening part5, and the opening part5is covered with the top plate20. Further, the top plate20is provided with a first fuel pump connection part23(hereinafter, also simply referred to as a “first connection part23”) and a fuel pump connection part25(hereinafter, also simply referred to as a “second connection part25”).

A connector7connected to one end of a tube8joined to the internal combustion engine or the like is connected to the first connection part23. Moreover, as illustrated inFIG.4, a through hole21ais formed at a predetermined position of the top plate20, and a pump connection pipe21hangs down from a back-side peripheral edge of this through hole21a. By connecting a connection pipe (not illustrated) to this pump connection pipe21, the fuel pump10and the first connection part23are connected to each other via the connection pipe (not illustrated).

On the other hand, to the second connection part25is connected an electric connector (not illustrated) joined to electric supply wiring to the fuel pump10. Moreover, the fuel pump10and the second connection part25are electrically connected via wiring (not illustrated).

The above-described connector7and the electric connector (not illustrated) constitute a “connection member” in the present invention. Note that a checker7athat can be removed when connection with the first connection part23is completed is mounted on an outer periphery of the connector7.

As illustrated inFIGS.2to4, the protection structure for the fuel pump connection part (hereinafter, also simply referred to as a “protection structure”) of the present invention is for protecting the fuel pump connection parts23,25as described above, and has the top plate20that covers the opening part5of the fuel tank1and has the fuel pump connection parts23,25, and a cover member30that covers the top plate20and the fuel pump connection parts23,25.

As illustrated inFIG.4, a plurality of frame mounting claws11are provided in a protruding manner from a peripheral edge of the opening part5. An annular frame15made of a metal is mounted on the plurality of frame mounting claws11(seeFIG.1). This annular frame15is disposed on a front-side peripheral edge of the top plate20and presses the top plate20to suppress detachment of the top plate20from the opening part5. Moreover, in the annular frame15, a plurality of grooves15aare formed along a peripheral direction (seeFIG.1).

By inserting the plurality of frame mounting claws11into the plurality of grooves15a, respectively, and rotating the annular frame15in a predetermined direction, each of the frame mounting claws11is engaged with each of the grooves15a, so that the annular frame15is mounted in a state being retained so as to prevent coming-off (seeFIGS.3and4).

While as described above, the cover member30of this embodiment is indirectly attached to the top plate20via the annular frame15, the cover member30may be directly attached to the top plate20.

Moreover, the first connection part23that is substantially L-shaped and tubular is provided at a position of the top plate20that is aligned with the pump connection pipe21. This first connection part23includes a base part23athat is provided in a protruding manner from a front-side peripheral edge of the through hole21a, and an extension part23bextending in a horizontal direction from an upper end of this base part23a. As illustrated inFIGS.6and7, the connector7as the connection member is connected to the extension part23b.

Further, as shown inFIG.3, the second connection part25having a substantially square frame shape is provided at a position of the top plate20adjacent to the first connection part23. As described above, to the second connection part25are connected the electric connector (not illustrated) joined to the electric supply wiring to the fuel pump10, and the like.

Note that the shapes and the structures of the top plate and the fuel pump connection part are not limited to the aspect described above. Moreover, while this top plate is provided with the two fuel pump connection parts, a number of the fuel pump connection parts may be one, or may be three or more.

Next, the cover member30will be described.

As illustrated inFIGS.2and3, this cover member30includes a top plate cover part31having a substantially disk shape so as to cover the top plate20. Referring also toFIG.8, this top plate cover part31includes a base part33formed in a constant thickness, and a peripheral edge part35formed on an outer periphery of the base part33and formed to be thicker than the base part33. An inner periphery35aof the peripheral edge part35has a shape gradually increasing in thickness toward an outer diameter direction from a boundary part with the base part33. As a result, a rigidity of the top plate cover part31increases toward an outer diameter side. Moreover, as described above, since the inner periphery35aof the peripheral edge part35is made thick, a length on an inner surface side of the top plate cover part31is longer than a length of an inner periphery35a′ that is not thick.

Moreover, a fitting recessed part35bhaving an annular recessed shape is formed inside the peripheral edge part35, and an outer peripheral edge part15bof the annular frame15is fitted into this fitting recessed part35b. As a result, as illustrated inFIGS.3and4, the cover member30is attached to the top plate20via the annular frame15. At this time, the top plate cover part31is disposed with respect to the top plate20with a gap interposed therebetween (seeFIG.4).

Further, a seal flange37extends obliquely outward from a back-side outer periphery of the peripheral edge part35. As described above, when the cover member30is attached to the top plate20via the annular frame15, the seal flange37elastically abuts (abuts in an elastically deformed state) on a surface of the fuel tank1. As a result, a gap between the cover member30and the surface of the fuel tank1is sealed, and sealing performance is improved.

Moreover, as illustrated inFIG.8, a notch37ais formed on an outer periphery of a base end part of the seal flange37. Since this notch37ais provided, a reaction force received from the tank surface when the seal flange37abuts on the surface of the fuel tank1is reduced, and the seal flange37is easily elastically deformed.

Moreover, as illustrated inFIGS.4and5, a first hole part39having a substantially rectangular elongated hole shape is formed at a position of the top plate cover part31that is aligned with the first connection part23formed on the top plate20. Further, a second hole part41having a substantially square hole shape is formed at a position of the top plate cover part31that is aligned with the second connection part25provided on the top plate20(seeFIGS.5and9). In a state where the cover member30is attached to the top plate20, the first connection part23protrudes from the first hole part39, and the second connection part25protrudes from the second hole part41.

Moreover, a first connection-part cover part45(hereinafter, also simply referred to as a “first cover part45”) is extended from a front-side peripheral edge of the first hole part39so as to cover the first connection part23and the connector7connected thereto. On the other hand, a second connection-part cover part55(hereinafter, also simply referred to as a “second cover part55”) is extended from a front-side peripheral edge of the second hole part41so as to cover the second connection part25and the connection member (not illustrated) (here, the above-mentioned electric connector) connected thereto.

The cover parts45,55respectively have movable parts47,57that are movable in a separating direction and an approaching direction with respect to a front surface side of the top plate cover part31. In a state where the movable parts47,57have moved from the front surface side of the top plate cover part31, the first connection part23and the second connection part25are exposed, and the connection members can be connected.

Moreover, the first cover part45has a fixed part46fixed to the top plate cover part31, and a fragile part48having a lower rigidity than the fixed part46and the movable part47is provided between the fixed part46and the movable part47.

More specifically, as illustrated inFIGS.3to5, the fixed part46of the first cover part45in this embodiment is constituted of a pair of side walls46a,46aerected from both side peripheral edges in a longitudinal direction of the first hole part39, an end wall46bjoining one-ends in the longitudinal direction of the side walls46a,46ato each other, and a ceiling wall46cjoining the side walls46a,46aand the end wall46bto each other, and has a substantially rectangular frame shape that surrounds the first hole part39and has another end side in the longitudinal direction opened.

Moreover, on the other end side (opening side) in the longitudinal direction of the fixed part46, the fragile part48having a thickness thinner than thicknesses of the fixed part46and the movable part47is disposed, and the movable part47is provided continuously to the other end side in the longitudinal direction of the fixed part46via this fragile part48. As illustrated inFIGS.2and5, the movable part47of this embodiment has a substantially semi-cylindrical shape extending by a predetermined length with a semicircular cross-sectional shape slightly larger than a transverse cross-sectional shape of the fixed part46, and a distal end side in an extension direction is opened.

Moreover, as illustrated inFIG.9, both-side end surfaces47a,47aof the movable part47are separated from a front surface of the top plate cover part31, so that the movable part47is movable. Further, flange parts47b,47bare provided in a protruding manner from an outside of the both-side end surfaces47a,47aof movable part47. These flange parts47b,47bfacilitate gripping and movement of the movable part47and increase rigidity of the movable part47itself.

Then, in this first cover part45, when the movable part47is moved in the direction separating from the front surface of the top plate cover part31, the movable part47is elastically deformed and turned up so as to have a flat shape as illustrated inFIG.9with respect to the fixed part46via the fragile part48, and when the movable part47is further moved in a direction approaching the fixed part46, as illustrated inFIG.6, the movable part47is moved so as to be folded back and the first connection part23is exposed.

Moreover, as illustrated inFIG.5, a wall part49having a height higher than the front surface of the top plate cover part31is erected on the front-side peripheral edge of the first hole part39. The wall part49of this embodiment is constituted of a pair of extension walls49a,49aextending from the other end side (opening side) in the longitudinal direction of the pair of side walls46a,46aconstituting the fixed part46toward the extension direction of the movable part47, and a joining wall49bjoining dismal ends of this pair of extension walls49a,49ain the extension direction, and has a frame shape surrounding the base part23aof the first connection part23. Further, as shown inFIG.9, a groove part49chaving an arc shape adapted to an outer peripheral shape (circular shape) of the extension part23bof the first connection part23is formed in an upper edge part of the joining wall49b.

Further, as shown inFIG.9, on the front surface side of the top plate cover part31and on one side of the movable part47of the first cover part45, a side wall part51extending in parallel along an extension direction of the first cover part45is erected at an interval that does not interfere when the movable part47is deformed to have a flat shape. The side wall part51restrains a liquid such as a cleaning liquid from flowing into a gap between the movable part47of the first cover part45and the top plate cover part31, and does not interfere when the movable part47is deformed into a flat shape (seeFIG.9), and does not hinder the moving operation of the movable part47.

Moreover, as described above, the top plate cover part31is disposed with respect to the top plate20with the gap interposed therebetween (seeFIG.4), and ribs53extending toward the top plate20and abutting on a front surface side of the top plate20are provided on a back surface side of the top plate cover part31and in the vicinity of the wall part49. As shown inFIG.4, in this embodiment, one of the ribs53is vertically provided from a position closest to the wall part49on the back surface side of the top plate cover part31, and the other rib53is vertically provided from a position away from the foregoing rib53by a predetermined length.

On the other hand, the second cover part55in this embodiment has a substantially square cover shape opened in the same direction as the opening of the first cover part45in the extension direction. In this embodiment, as shown inFIG.9, a frame-shaped inner cover54is erected from the front-side peripheral edge of the second hole part41having a substantially square hole shape, and the second cover part55is disposed outside the inner cover54. The second cover part55has a movable part57having a square frame shape with one side part opened, and a base end part58thereof is joined to the top plate cover part31. Moreover, flange parts57b,57bthat facilitate movement of the movable part57and enhance rigidity are provided in a protruding manner from an outside of both-side end surfaces57a,57aof the movable part57similarly to the flange parts47bof the first cover part45.

In the second connection-part cover part55, when the movable part57is moved in the direction separating from the front surface of the top plate cover part31, the movable part57is elastically deformed so as to be turned up via the base end part58, and the second connection part25is exposed.

Moreover, as illustrated inFIG.9, the second cover part55is disposed on the side of the first cover part45at an interval that prevents interference when the movable part47of the first cover part45moves so as to form a flat shape. Therefore, when the movable part47is deformed to have a flat shape, it is prevented from interfering with the second cover part55, and the moving work of the movable part47is not hindered.

The top plate cover part31, the first cover part45, and the second cover part55described above are integrally formed. In this embodiment, all the parts (top plate cover part, both the cover parts, and the like) constituting the cover member30are integrally formed of an elastic material such as rubber. Note that the cover member may be formed of a synthetic resin material such as polyethylene (PE) or polyoxymethylene (POM) in addition to the foregoing elastic material. However, in the cover member30, at least the movable parts47,57are preferably formed of an elastic material. Moreover, the cover member is preferably formed of a material having excellent acid resistance such as rubber (EPDM, MBR).

Moreover, the shapes and the structures of the top plate cover part, the hole parts, and the connection-part cover parts of the cover member described above are not limited to the above aspects. Note that while in the cover member of this embodiment, the two hole parts and the two connection-part cover parts are provided, it is possible to provide one or three or more hole parts and connection-part cover parts corresponding to the fuel pump connection part provided on the top plate side.

Next, actions and effects of the protection structure having the above constitution will be described.

In this embodiment, as shown inFIG.1, the cover member30is attached to the top plate20via the annular frame15from a state where the annular frame15is retained by the plurality of frame mounting claws11so as to prevent coming-off and is mounted, the plurality of frame mounting claws being provided at the peripheral edge of the opening part5. That is, after the first cover part45and the second cover part55of the cover member30are aligned with the first connection part23and the second connection part25of the top plate20, the cover member30is pushed into the top plate20.

Then, the first connection part23and the second connection part25of the top plate20protrude from the first hole part39and the second hole part41of the cover member30, respectively, and the seal flange37of the cover member30abuts on the surface of the fuel tank1and is flexurally deformed. Further, the outer peripheral edge part15bof the annular frame15presses the back side of the peripheral edge part35of the top plate cover part31, and the peripheral edge part35is flexurally deformed so as to warp toward an outside of the front side of the top plate cover part31.

At this time, as illustrated inFIG.8, in the top plate cover part31in this embodiment, the inner periphery35aof the peripheral edge part35gradually becomes thicker in the outer diameter direction, the rigidity of the top plate cover part31increases toward the outer diameter side, and the length on the inner surface side of the top plate cover part31is longer than the length of the inner periphery35a′ that is not thick. Therefore, when the cover member30is pushed into the top plate20, by pushing a vicinity of a boundary between the base part33and the peripheral edge part35of the top plate cover part31, the peripheral edge part35can be easily flexurally deformed toward an outside of the front side of the top plate cover part31.

Further, when the cover member30is pushed into the top plate20, the outer peripheral edge part15bof the annular frame15enters and fits into the fitting recessed part35bof the cover member30, and the peripheral edge part35elastically returns to the base part33, so that the cover member30can be attached to the top plate20via the annular frame15as illustrated inFIGS.3and4.

In the above state, the top plate20is covered with the top plate cover part31, the first connection part23of the top plate20protruding from the first hole part39of the cover member30is covered with the first cover part45, and further, the second connection part25of the top plate20protruding from the second hole part41of the cover member30is covered with the second cover part55. Note that in this state, the extension part23bof the first connection part23is supported by the groove part49cof the joining wall49bof the wall part49(seeFIG.9), and the plurality of ribs53vertically provided from the back surface of the top plate cover part31abut on the front surface of the top plate20(seeFIG.4).

Moreover, in a state where the cover member30is attached to the top plate20via the annular frame15, the seal flange37elastically abuts on the surface of the fuel tank1. At this time, the seal flange37is easily elastically deformed by reducing, by the notch37a(seeFIG.8), the reaction force received from the tank surface when the seal flange37abuts on the surface of the fuel tank1, the notch37abeing formed on the outer periphery of the base end part of the seal flange37. As a result, even when the fuel tank is deformed due to pressure fluctuation or the like caused by temperature, the seal flange37is elastically deformed as appropriate, so that a state in contact with the surface of the fuel tank1can be maintained Therefore, the peripheral edge part35of the top plate cover part31can be retained at a predetermined position, and the outer peripheral edge part15bof the annular frame15can be restrained from being detached from the fitting recessed part35b.

When the connector7is connected to the first connection part23, the movable part47of the first cover part45is moved in the separating direction with respect to the front surface of the top plate cover part31. Then, in this first cover part45, the movable part47is elastically deformed and turned up so as to have a flat shape with respect to the fixed part46via the fragile part48as illustrated inFIG.9, and when the movable part47is further moved in the direction approaching the fixed part46, the movable part47is moved so as to be folded back as illustrated inFIG.6, and the first connection part23is exposed.

In this state, as illustrated inFIG.6, the connector7with the checker7ais connected to the first connection part23. When the connection between the connector7and the first connection part23is completed, the checker7ais enabled to be removed, and thus the checker7ais removed. Thereafter, as illustrated inFIG.7, by moving the movable part47in the approaching direction with respect to the front surface of the top plate cover part31, the first connection part23and a part of the connector7connected thereto can be covered with the movable part47.

On the other hand, also when the connection member such as the electrical connector is connected to the second connection part25, by moving the movable part57of the second cover part55in the separating direction with respect to the front surface of the top plate cover part31, the movable part57is elastically deformed so as to be turned up via the base end part58, and the second connection part25is exposed. Thereafter, after the connection member such as the electrical connector is connected to the second connection part25, the movable part57is moved in the approaching direction with respect to the front surface of the top plate cover part31, which makes it possible to cover the second connection part25and the connection member such as the electrical connector connected thereto with the movable part57.

Thus, in this protection structure, as described above, after the cover member30is attached so as to cover the top plate20and the connection parts23,25in the state where the connection parts23,25protrude from the hole parts39,41of the cover member30, the movable parts47,57of the cover parts45,55are moved in the separating direction from the front surface side of the top plate cover part31to expose the cover parts45,55, which makes it possible to connect the connection members such as the connector7and the electrical connector to the connection parts23,25, respectively. Therefore, the cover member30can be easily attached as compared with a case where the top plate cover part and the connection-part cover part are separate bodies, and are separately attached.

Moreover, as described above, after the connection members such as the connector7and the electrical connector are connected to the connection parts23,25, the movable parts47,57are moved in the approaching direction with respect to the front surface side of the top plate cover part31, which makes it possible to cover the first connection part23and the connector7, and the second connection part25and the connection member such as the electrical connector with the cover parts45,55. Therefore, the connection parts23,25and a part of the connection members connected thereto can be protected, and the inflow of a liquid containing strong acid such as a vehicle cleaning liquid, a rust removing agent, or a brake cleaner can be suppressed.

Moreover, in this embodiment, as illustrated inFIG.6, when the movable part47of the first cover part45is moved in the separating direction from the front surface side of the top plate cover part31, the movable part47can be moved with respect to the fixed part46via the fragile part48having a lower rigidity. Therefore, since the movable part47of the first cover part45can be easily moved, connection workability of the connector7with respect to the first connection part23can be enhanced.

Further, in this embodiment, at least the movable parts47,57of the cover parts45,55are formed of an elastic material. Therefore, when the movable parts47,57are moved, the movable parts47,57can be moved so as to be turned up in the separating direction from the front surface side of the top plate cover part31by using the elasticity, so that the connection parts23,25can be easily exposed.

Moreover, in this embodiment, as illustrated inFIGS.3and9, the wall part49having a height higher than the front surface of the top plate cover part31is erected on the front-side peripheral edge of the first hole part39. Therefore, even if a liquid such as a cleaning agent attempts to flow into the first hole part39from a gap between the movable part47and the front surface of the top plate cover part31, the liquid can be blocked by the wall part49, so that the inflow of the liquid into the first hole part39can be suppressed.

Further, as shown inFIG.4, the top plate cover part31is disposed with the gap with respect to the top plate20, and the plurality of ribs53extending toward the top plate20and abutting on the front surface side of the top plate20are provided on the back surface side of the top plate cover part31and in the vicinity of the wall part49. Therefore, even if the vicinity of the wall part49is pressed by an external force or the like, the plurality of ribs53abut on the front surface side of the top plate20, and receives the external force or the like, so that deformation of the wall part49can be suppressed. As a result, it is possible to suppress the inflow of the liquid into the first hole part39more reliably.

Note that the present invention is not limited to the above-described embodiments, and various modifications can be made within the scope of the gist of the present invention, and such embodiments are also included in the scope of the present invention.

REFERENCE SIGNS LIST