Duct installation structure

A duct installation structure in which an air conditioning duct for sending warm air or cold air into a vehicle interior of an automobile is attached to a vehicle interior structure member and an outlet grill is attached to an outlet opening end portion of the air conditioning duct. A grill fixing portion to which the outlet grill is to be fixed is integrally molded with a duct main body portion at the outlet opening end portion of the air conditioning duct. The outlet grill is directly fixed to the grill fixing portion. The outlet opening end portion of the air conditioning duct including, at one point near its center in a width direction, a fastening fixing portion that is fastened and fixed to the vehicle interior structure member and including, at its opposite ends in the width direction, a pair of contact portions for coming in contact with the vehicle interior structure member.

TECHNICAL FIELD

The present invention relates to a duct installation structure in which an air conditioning duct for sending warm air or cold air into a vehicle interior of an automobile is attached to a vehicle interior structure member and an outlet grill is attached to an outlet opening end portion of the air conditioning duct.

BACKGROUND ART

There is a duct installation structure in which a heater duct for sending warm air into a vehicle interior of an automobile is installed (Patent Document 1).

As shown inFIG. 10, the prior-art duct installation structure is formed by attaching the heater duct91to a floor of the vehicle interior and attaching an outlet grill92to an outlet opening end portion911of the heater duct91.

The heater duct91is a resin molded article obtained by blow molding.

The heater duct91is fixed to the floor by a bolt941at an iron plate bracket93attached to the outlet opening end portion911by rivets931. After the heater duct91is attached onto the floor, a floor carpet is laid over the heater duct91and then the outlet grill92is fixed to the iron plate bracket93by bolts942.

In this way, it is possible to obtain the duct installation structure in which the heater duct91is fixed to the floor and the outlet grill92is disposed at the outlet opening end portion911.

In the prior-art duct installation structure, however, the iron plate bracket93is attached to the opening end portion911of the heater duct91, which increases the number of parts. As a result, the duct installation structure increases in weight and the cost increases as well. Because the number of parts increases, dimensions of the parts are likely to vary. In other words, dimensional accuracy is required between the heater duct91and the iron plate bracket93and also between the iron plate bracket93and the outlet grill92, for example, and therefore it is necessary to further reduce dimensional variations of respective component parts.

DISCLOSURE OF THE INVENTION

Problems to be Solved by the Invention

The present invention has been made in view of the above conventional problems and an object of the present invention is to provide a duct installation structure with fewer component parts that can achieve reduction in weight and cost.

Means for Solving the Problems

The present invention provide a duct structure, comprising:

an air conditioning duct for sending warm air or cold air into a vehicle interior of an automobile attached to a vehicle interior structure member, and

an outlet grill attached to an outlet opening end portion of the air conditioning duct,

wherein a grill fixing portion to which the outlet grill is to be fixed is integrally molded with a duct main body portion at the outlet opening end portion of the air conditioning duct, and

the outlet grill is directly fixed to the grill fixing portion.

Next, operation and effects of the present invention will be described.

In the duct installation structure, the grill fixing portions are integrally molded with the duct main body portion. The outlet grill is directly fixed to the grill fixing portions. This enables the outlet grill and the duct main body portion to be directly fixed to each other without interposing a bracket therebetween. Therefore, the number of component parts of the duct installation structure can be reduced.

As a result, it is possible to achieve reduction in weight and cost of the duct installation structure.

As described above, according to the present invention, it is possible to provide a duct installation structure with fewer component parts that can achieve reduction in weight and cost.

BEST MODE FOR CARRYING OUT THE INVENTION

In the present invention, the air conditioning duct may be made of a resin molded article formed by blow molding, for example.

Examples of the air conditioning duct include a heater duct for sending warm air, and a cooler duct for sending cold air.

Examples of the vehicle interior structure member include a floor and a ceiling panel of the vehicle interior.

It is preferable that the outlet opening end portion of the air conditioning duct has, at one point near its center in a width direction, a fastening fixing portion that is fastened and fixed to the vehicle interior structure member and is provided, at its opposite ends in the width direction, with a pair of contact portions for coming in contact with the vehicle interior structure member.

In this case, it is possible to stably fix the outlet opening end portion of the air conditioning duct to the floor and it is also possible to secure the rigidity of the outlet opening end portion.

It is preferable that the grill fixing portion is formed between the fastening fixing portion and the contact portion of the outlet opening end portion and is provided with a through hole, the outlet grill is fixed to the grill fixing portion by a spring nut that is disposed and fitted to pinch the grill fixing portion from upper and lower sides and a bolt screwed into the spring nut, the grill fixing portion is provided with a rib protruding in a thickness direction of the grill fixing portion, and an inner face of the spring nut is in contact with the rib.

In this case, it is possible to easily and reliably fix the outlet grill to the grill fixing portions. Because the rib is formed at the grill fixing portion, the spring nut can reliably pinch the grill fixing portion. If the rib is not provided and thicknesses of the grill fixing portion vary, a force of the spring nut for pinching the grill fixing portion may become insufficient or it may become difficult to fit the spring nut over the grill fixing portion.

In other words, if the thickness of the grill fixing portion is excessively small, the force of the spring nut for pinching the grill fixing portion may become insufficient. As a result, the spring nut may come off or be displaced before fixing the outlet grill with the bolt after disposing the spring nut at the grill fixing portion.

If the thickness of the grill fixing portion is excessively large, on the other hand, an insertion load at the time of attaching the spring nut to the grill fixing portion may become so large that attachment work of the spring nut may become difficult.

Especially when the duct main body portion is molded by blow molding, it is difficult to control the thickness of the grill fixing portion and the above problems are likely to occur.

Therefore, in the present invention, by providing the rib to the grill fixing portion, height of the rib provides a fitting thickness required to be fitted in the spring nut irrespective of the thickness of the grill fixing portion, which can suppress variations in the fitting thickness. As a result, it is possible to prevent coming off and displacement of the spring nut to thereby improve workability in attaching the spring nut to the grill fixing portion. Moreover, providing the rib reduces a contact area between the spring nut and the grill fixing portion to thereby reduce the insertion load. As a result, the spring nut can be smoothly attached to the grill fixing portion.

It is preferable that the grill fixing portion is formed at a plurality of positions in the outlet opening end portion.

In this case, it is possible to stably fix the outlet grill to the outlet opening end portion.

Embodiment

A duct installation structure according to an embodiment of the present invention will be described by usingFIGS. 1 to 8.

In the duct installation structure1in the present embodiment, as shown inFIGS. 1 and 2, a heater duct2for sending warm air into a vehicle interior of an automobile is attached to a floor6(floor panel61) that is a vehicle interior structure member and an outlet grill3is attached to an outlet opening end portion21of the heater duct2.

As shown inFIGS. 3 and 4, at the outlet opening end portion21of the heater duct2, grill fixing portions22for fixing the outlet grill3are integrally molded with a duct main body portion20.

The outlet grill3is directly fixed to the grill fixing portions22.

The heater duct2is formed of a resin molded article formed by blow molding. The heater duct2is in a cylindrical shape having, inside itself, a warm air flow path in which warm air flows. The outlet opening end portion21is formed at one end of the warm air flow path. The heater duct2has a flat shape having substantially flat upper and lower faces.

The heater duct2is fixed to the floor6of the vehicle interior and then the upper face of the heater duct2excluding the outlet opening end portion21is covered with a floor carpet63. Then, the outlet grill3is attached to the outlet opening end portion21.

As shown inFIGS. 4 and 5, the grill fixing portions22are formed on a lower plate portion24constituting a lower face of the outlet opening end portion21and provided with through holes221. The outlet grill3is fixed to the grill fixing portions22by spring nuts4that are disposed and fitted to pinch the grill fixing portions22from upper and lower sides and bolts51screwed into the spring nuts4. As shown inFIGS. 7 and 8, at each of the grill fixing portions22, ribs222protruding in a direction of a thickness of the grill fixing portion22are formed. An inner face41of the spring nut4is in contact with the ribs222.

As shown inFIG. 7, each of the spring nuts4has an upper chip43and a lower chip44facing each other and formed successively with a folded portion42interposed therebetween. The spring nut4is fitted over the grill fixing portion22while the upper chip43and the lower chip44are biased in such directions as to approach each other. A through hole451through which the bolt51is inserted is formed in the upper chip43and a pawl452to be screwed engagement with the bolt51is provided to the lower chip44.

As shown inFIG. 1, the lower plate portion24constituting the lower face of the outlet opening end portion21of the heater duct2protrudes farther forward than an upper plate portion25constituting an upper face of the outlet opening end portion21. The grill fixing portions22are formed at left and right two positions in a width direction of the lower plate portion24protruding forward.

As shown inFIGS. 1 and 3, a pair of contact portions23for coming in contact with the floor6is provided at opposite ends of the lower face of the outlet opening end portion21of the heater duct2. In other words, the pair of left and right contact portions23is formed outside the pair of left and right grill fixing portions22.

The outlet opening end portion21has a fastening fixing portion that is fastened and fixed, at one point near its center in the width direction, to the floor6. In other words, in the lower plate portion24of the outlet opening end portion21at a substantially intermediate position between the pair of left and right grill fixing portions22, a bolt insertion hole241through which a bolt52for fixing the outlet opening end portion21of the heater duct2to the floor6is to be inserted is formed. The outlet opening end portion21of the heater duct2is fixed, as shown inFIG. 3, at the one point near the center in the width direction, to the floor6by inserting the bolt52through the bolt insertion hole241and screwing the bolt52into a screw grommet62provided to the floor6. In this manner, the fastening fixing portion is configured.

As shown inFIG. 3, each of the grill fixing portions22is formed to rise higher than the lower plate portion24located to the left and right of the grill fixing portion22. As shown inFIGS. 7 and 8, at each of the grill fixing portions22, the pair of ribs222is formed on opposite sides of the through hole221along an opening direction of the outlet opening end portion21. As shown inFIG. 8, each of the ribs222has a substantially semicircular shape protruding upward in section orthogonal to a longitudinal direction.

The outlet grill3is formed of a resin molded article obtained by injection molding or the like and formed by forming outlets32in a frame body31as shown inFIGS. 1 and 6. As shown inFIGS. 3,7, and8, at each of lower side plate portions321constituting lower sides of the outlets32, a fixing seat portion33for coming in contact with the grill fixing portion22of the heater duct2is formed in such a manner as to sink below the lower side plate portion321. As shown inFIGS. 6 and 8, a bolt insertion hole331through which the bolt51is to be inserted is formed in each of the fixing seat portions33.

As shown inFIGS. 3,7, and8, a cap332for covering the fixing seat portion33is fitted in an upper portion of the fixing seat portion33. An upper face of the cap332forms substantially the same plane as an upper face of the lower side plate portion321of the outlet grill3around the cap332, which improves the design of the outlet grill3.

To install the heater duct2and the outlet grill3on the floor6of the vehicle interior, the heater duct2is first fixed to the floor panel61constituting the floor6as shown inFIG. 3. A square hole is formed in the floor panel61and the screw grommet62in which the bolt52is to be screwed is fitted in the square hole. Then, by inserting the bolt52through the bolt insertion hole241provided in the lower plate portion24of the outlet opening end portion21of the heater duct2and screwing the bolt52into the screw grommet62, the outlet opening end portion21of the heater duct2is fixed to the floor panel61.

The spring nut4is fitted over each of the grill fixing portions22of the heater duct2. The spring nut4may be fitted over the grill fixing portion22before or after fixing the heater duct2to the floor panel61.

Then, the floor carpet63is laid over the whole floor6so as to cover the upper face of the heater duct2. At this time, in order to expose the outlet opening end portion21of the heater duct2from the floor carpet63, an opening portion is formed in advance in a predetermined position of the floor carpet63. In this way, the heater duct2excluding the outlet opening end portion21is covered with the floor carpet63. The outlet grill3is then fixed to the outlet opening end portion21of the heater duct2exposed from the floor carpet63.

In other words, as shown inFIGS. 3,7, and8, the pair of fixing seat portions33of the outlet grill3is brought into contact with the spring nuts4disposed at the pair of grill fixing portions22of the heater duct2. Then, the bolts51are inserted through the bolt insertion holes331of the respective fixing seat portions33and the through holes221of the respective grill fixing portions22and screwed into the spring nuts4. In this way, as shown inFIGS. 2 and 3, the outlet grill3is fixed to the outlet opening end portion21of the heater duct2.

At this time, as shown inFIG. 3, the frame body31of the outlet grill3retains an opening end631of the floor carpet63. The caps332for covering the fixing seat portions33are fitted in the upper portions of the fixing seat portions33where head portions of the bolts51are disposed.

By this process, the duct installation structure1(FIG. 2) is obtained in which the heater duct2fixed to the floor6is covered with the floor carpet63and the outlet opening end portion21of the heater duct2is open into the vehicle interior via the outlet grill3. It is to be noted that inFIG. 2, the floor carpet63is not shown.

Next, operation and effects of the present embodiment will be described.

In the duct installation structure1, the grill fixing portions22are integrally molded with the duct main body portion20. The outlet grill3is directly fixed to the grill fixing portions22. In this way, it is possible to directly fix the outlet grill3and the duct main body portion20to each other without interposing a bracket therebetween. Therefore, the number of component parts of the duct installation structure1can be reduced.

As a result, it is possible to achieve reduction in weight and cost of the duct installation structure1.

The pair of contact portions23is provided at the opposite ends of the lower face of the outlet opening end portion21of the heater duct2. Therefore, it is possible to stably fix the outlet opening end portion21of the heater duct2to the floor6and it is also possible to secure rigidity of the outlet opening end portion21.

The outlet grill3is fixed to the grill fixing portions22by the spring nuts4that are disposed and fitted to pinch the grill fixing portions22from the upper and lower sides and the bolts51screwed into the spring nuts4. In this way, the outlet grill3can be easily and reliably fixed to the grill fixing portions22. Because the ribs222are formed at the grill fixing portions22as shown inFIG. 8, the spring nuts4can reliably pinch the grill fixing portions22.

If the ribs222(seeFIG. 8) are not provided as shown inFIG. 9and thicknesses t of the grill fixing portions22vary, a force of the spring nut4for pinching the grill fixing portion22may become insufficient or it may become difficult to fit the spring nut4over the grill fixing portion22.

In other words, if the thickness t of the grill fixing portion22is excessively small, the force of the spring nut4for pinching the grill fixing portion22may become insufficient. As a result, the spring nut4may come off or be displaced before fixing the outlet grill3with the bolt51after disposing the spring nut4at the grill fixing portion22.

If the thickness t of the grill fixing portion22is excessively large, on the other hand, an insertion load at the time of attaching the spring nut4to the grill fixing portion22may become so large that attachment of the spring nut4may become difficult.

Especially because the duct main body portion20is molded by blow molding, it is difficult to control the thickness t of the grill fixing portion22and the above problems are likely to occur.

Therefore, in the present invention, by providing the ribs222to each of the grill fixing portions22, heights of the ribs222provide a fitting thickness T required to be fitted in the spring nut4irrespective of the thickness t of the grill fixing portion22, which can suppress variations in the fitting thickness T. As a result, it is possible to prevent coming off and displacement of the spring nut4to thereby improve workability in attaching the spring nut4to the grill fixing portion22. Moreover, providing the ribs222reduces a contact area between the spring nut4and the grill fixing portion22to thereby reduce the insertion load. As a result, it is possible to smoothly attach the spring nut4to the grill fixing portion22.

Because the grill fixing portions22are formed at two positions of the outlet opening end portion21, the outlet grill3can be stably fixed to the outlet opening end portion21.

As described above, according to the embodiment, it is possible to provide a duct installation structure with fewer component parts that can achieve reduction in weight and cost.

Although the present invention is applied to the duct installation structure in which the heater duct is attached to the floor of the vehicle interior in the above embodiment, it is also possible to apply the invention to the duct installation structure in which a cooler duct is attached to a ceiling of a vehicle interior.