JPH078689U - Duct connection structure - Google Patents

Abstract

(57) [Abstract] [Purpose] Use a fastener with a band body curved in the shape of a duct bulge to attach the outer circumference of a flexible hose attached to a duct provided with a bulge from above the bulge. Tighten and prevent displacement of the hose when pressurizing to maintain airtightness. [Structure] A flexible hose 3 is attached to a duct 1 having a bulged portion 2. The width direction cross section of the band body 5 of the tightening tool 4 including the band body 5 and the bolt body 6 has the same shape as the bulging portion 2, and the outer circumference of the hose 3 on the bulging portion 2 is tightened.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a duct connecting structure that requires airtightness such as connecting an air intake duct and an air cleaner of an internal combustion engine, and relates to a duct connecting structure in which a flexible hose is attached to the duct and tightened with a fastener.

[0002]

[Prior art]

 An example of a duct connecting structure in which a flexible hose is attached to a duct and the hose is tightened with a fastener is shown in FIG. 3, for example. The duct 1 is made of synthetic resin, has an annular bulge 2 near its one end, which bulges larger than the outer diameter of the duct and projects in the outer peripheral direction, and the other end is connected to an unillustrated intemmark manifold of the internal combustion engine. It has a mounting part. The hose 3 is made of synthetic rubber and synthetic resin and has flexibility on one side and rigidity on the other side. The inner diameter of the one side is slightly smaller than the outer diameter of the duct 1, and the other end is The portion has a connecting portion connected to an air cleaner or an air flow meter (not shown), and one side is deeply fitted and attached to one end of the duct 1. The fastening tool 14 has a toothed shape in which a flat strip is curved to an inner diameter larger than the outer diameter of the hose 3, one end is provided with a locking portion, and the other end is cut out in a part of the strip in the outer peripheral longitudinal direction. A hose on the other side with respect to the duct bulging portion 2. The band body 15 is formed with a toothed portion, and the bolt body 6 is provided with a worm gear that meshes with the toothed portion and is locked with the locking portion. The hose 3 is located at the outer circumference of the hose 3 and the bolt 6 is tightened to reduce the diameter in the circumferential direction to tighten the hose 3 and maintain airtightness with the duct 1. Therefore, the connecting portion between the duct 1 and the hose 3 is shielded from the outside air, and the combustion air passes through without sucking dust.

[0003]

[Problems to be solved by the device]

 In the conventional duct connection structure, the heat of the internal combustion engine causes a permanent strain in the tightening part of the hose, and the tightening force from the tightening tool is reduced. When a pressure is applied, the hose swells and the tightening part is pulled in the pulling direction to create a gap with the duct, and when sucking combustion air, dust enters through the gap.

[0004]

[Means for Solving the Problems]

 In a duct connection structure in which a flexible hose is attached to a duct having an annular bulge and the hose is tightened with a tightening tool consisting of a band body and a bolt body, in the width direction of the band body of the tightening tool. Make the cross section the same shape as the bulge and tighten the outer circumference of the hose located at the duct bulge.

[0005]

[Action]

 When pressure is applied to the hose, the hose expands and a pulling force is applied. At this time, the fastener is lifted up by the bulge of the hose at the end of the duct with the outermost periphery of the bulging part as the sakai, and conversely, the end of the hose is pressed inward to further compress the hose periphery and There is no deviation in

[0006]

【Example】

 Hereinafter, the illustrated embodiment will be described. The same components as those in the conventional example are designated by the same reference numerals and the description thereof will be omitted. The bulging portion 2 formed in the vicinity of one end of the duct in FIGS. 1 and 2 is formed by the wall of the duct 1 bulging in an annular shape larger than the outer diameter and the cross section protruding in an arc shape. One end of the duct 1 is made of synthetic rubber and has flexibility, and the other end is made of synthetic resin and is integrally molded. And is pressed and attached.

The fastener 4 includes a band body 5 and a bolt body 6. The band body 5 is a band metal whose outer surface is curved so as to match the outer surface of the duct bulging portion 2 and is increased by the wall thickness of the hose 3 and has an arcuate cross section. It is curved so as to have a larger inner diameter, a locking part is provided on one end side, and a part of the strip is continuously cut out in a crescent shape in the longitudinal direction of the outer periphery on the other end side to form a toothed part. There is. A bolt body 6 having a worm gear engraved on its tooth portion is meshed with the band body 5 and is rotatably pivotally supported on the locking portion. The fastening tool is not limited to the one described above, but the cross section has the same shape as the duct bulge and both ends of the circular curved metal strip are bent outward to form the insertion hole. Alternatively, the bolt may be inserted and tightened with a nut.

The fastener 4 is tightened around the outer periphery of the hose 3 attached to the duct 1 at the duct bulging portion 2, and the hose 3 is uniformly pressed against the entire surface of the duct bulging portion 2.

Therefore, in the duct connection structure of the embodiment, when the inside of the hose 3 is pressurized, the outermost circumference of the bulging portion 2 serves as a fulcrum and the end of the duct 1 of the fastener 4 is lifted outward. On the contrary, the end of the hose 3 is pressed inward, and the pressing force on the hose 3 by the fastener 4 is increased, so that the hose 3 is not displaced in the pull-out direction.

[0010]

[Effect of device]

 As described above, in the duct connection structure of the present invention, the band body of the fastener has the same cross section in the width direction as the bulging portion of the duct, and is attached to the duct and is located at the bulging portion. Since the outer circumference is tightened, a swelling of the hose during pressurization causes a new pressing force on the hose end side of the fastener, which compresses the hose and prevents displacement in the pulling direction. Therefore, no air gap is formed on the pressure contact surface between the hose and the duct, airtightness is maintained, and no dust enters.

[Brief description of drawings]

FIG. 1 shows a duct connecting structure of the present invention, (a) is a front view and (b) is a side view.

FIG. 2 is a central sectional view of FIG.

FIG. 3 is a front view showing a conventional duct connection structure.

[Explanation of symbols]

 1 duct 2 bulging part 3 hose 4, 14 tightening tool 5, 15 band body

Claims (1)

[Scope of utility model registration request] 1. A duct connecting structure in which a flexible hose is attached to a duct having an annular bulge, and the hose is tightened with a tightening tool composed of a band body and a bolt body. A duct connection structure in which the width direction cross section of the band body has the same shape as the bulging portion, and the outer circumference of the hose located at the duct bulging portion is tightened.