JPH0929822A - Manufacture of silencing hose - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the dimensional and shape accuracies of both ends of a hose, to omit or simplify the cutting operation of both end flashes of a parison and to reduce the cost by inhibiting to cover both the ends of the hose with both the end flashes of the parison when a silencing expanding chamber is formed on the outer periphery of the hose by blow molding. SOLUTION: A plug tube 5 is externally inserted to the outer peripheries of both ends of an air cleaner hose, 2 and set between the opened blowing split molds 10. A parison 14 is extruded to the outer periphery of the hose 2. The molds 10 are closed to contract the separate two positions 15 of the parison 14 by pinch-off units 12, the outer periphery of the hose 2 is circumferentially bound, and both the end flashes 16 of the parison 14 are made to side on the outer periphery of the tube 5. The air is blown into the parison 14 to mold a silencing expanding chamber 17.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sound deadening hose for canceling noise generated or propagating inside, and more specifically, a sound deadening expansion chamber is formed by blow molding on the outer periphery of a hose having a sound deadening communication hole. It relates to a sound deadening hose.

[0002]

2. Description of the Related Art A muffler hose of this type is often used as an air cleaner hose for an intake system of an internal combustion engine. FIG.
14 and 14 show a conventional sound deadening hose 50 and a method for manufacturing the same, which are manufactured in the following process order. An air cleaner hose 51 made of synthetic resin is formed by blow molding, injection molding, extrusion molding, etc., and a muffling communication hole 52 is formed in a part of the air cleaner hose 51 by machining or the like. The air cleaner hose 51 is set between the opened blow split molds (not shown) by a slide mechanism (not shown). A cylindrical parison 53 made of molten resin is extruded from the crosshead 57 onto the outer periphery of the air cleaner hose 51. By closing the blow split mold, the diameters of the portions 54 near both ends of the parison 53 are reduced, and the parison 53 is attached to both end edges of the outer peripheral surface of the air cleaner hose 51. By blowing air into the parison 53 through the muffling communication hole 52, the parison 53 is expanded to form the muffling expansion chamber 55. The blow split mold is opened, and the burr portions 56 on both ends of the parison 53 protruding from both ends of the air cleaner hose 51 are cut off.

[0003]

In general, separate extension hoses 58 are connected to both ends of the air cleaner hose 51 manufactured as described above, so that the dimensional and shape accuracy of the both ends must be high. However, if the parts 54 near both ends of the parison 53 are attached to both ends of the outer peripheral surface of the air cleaner hose 51 as described above, the outer peripheral surface of the same portion 54 determines the size and shape accuracy. Part 5
There was a problem that the size and shape accuracy of No. 4 were low. Therefore, conventionally, the outer peripheral surface of the same portion 54 is post-finished to improve the dimensional and shape accuracy, which is costly. Further, when the burr portions 56 on both ends of the parison 53 are cut off, the cutting marks affect the size and shape accuracy of the both end portions, so it is necessary to cut them with high precision, and the cutting work is troublesome. Further, since the clamps 59 such as wire clamps and band clamps are used to connect the extension hoses 58 to both ends of the air cleaner hose 51, the cost of parts is high.

Therefore, a first object of the present invention is to form a burr part on both ends of a parison up to both end edges of a hose when a muffling expansion chamber is formed by blow molding on the outer periphery of a hose having a muffler communication hole. The size and shape accuracy of both ends of the hose can be improved by not wearing them, and the cutting work of the burr parts at both ends of the parison can be omitted or simplified, and thus the cost can be reduced. It is to provide a manufacturing method. A second object of the present invention is to provide a method for manufacturing a sound deadening hose that can connect extension hoses to both ends of the hose at the time of blow molding without using a clamp, thereby achieving cost reduction. is there.

[0005]

SUMMARY OF THE INVENTION Therefore, claim 1 of the present application is provided.
A method of manufacturing a noise-canceling hose according to the invention of claim 1, wherein a plug tube is externally inserted on the outer circumference of both ends of the hose having a noise-canceling communication hole, and the step of setting the hose and the plug tube between the open blow split molds, and the hose and The process of extruding a cylindrical parison made of molten resin on the outer circumference of the plug pipe and closing the blow split mold reduce the diameters of the two parts of the parison at the cutting edge of the blow split mold to the outer peripheral surface of the hose. Around the two ends of the parison by expanding the gap between the two parts by tightly binding it in a circumferential shape and by pushing the burr on both ends of the parison onto the outer peripheral surface of the plug tube, and by blowing air into the parison through the muffling communication hole. Molding the chamber.

Further, in the method for manufacturing a noise-canceling hose according to a second aspect of the present invention, the connection ends of the extension hose are externally inserted to the outer circumferences of the both ends of the hose having the muffler communication holes, and a part of the connection end is exposed. The process of inserting the plug tube onto the outer circumference of the extension hose and setting the hose, the extension hose and the plug tube between the open blow split molds and the molten resin on the outer circumference of the hose, the extension hose and the plug tube. The process of extruding the cylindrical parison and closing the blow split mold reduce the diameters of the two locations apart from the parison at the cutting edge of the blow split mold to tightly bind the outer circumference of the hose in a circumferential manner. The part adjacent to the part is reduced in diameter to be tightly bound to the outer peripheral surface of the connecting end of the extension hose in a circular shape, and the burr on both ends of the parison is mounted on the outer peripheral surface of the plug pipe, and the parison is passed through the muffler communication hole. The by blowing air, and a step of forming a sound-absorbing expansion chamber is expanded between the parison two places.

According to the method of manufacturing a sound deadening hose of the first aspect of the present invention, since the burr portions at both ends of the parison are allowed to ride on the outer peripheral surface of the plug tube in the mold closing step, the both end burr portions are at both ends of the outer peripheral surface of the hose. It does not adhere to the edges. For this reason,
The dimensions and shape accuracy of both ends of the outer surface of the hose do not deteriorate,
Of course, it is not necessary to finish the both ends. Further, the burr portions at both ends can be cut from any appropriate position, and the cut marks do not affect the size and shape accuracy of both ends of the hose, so that the cutting is not required to be accurate, and the cutting work is not troublesome.
Further, the cutting work of the burr portions at both ends can be sometimes omitted.

In addition to the above-mentioned action, according to the method for manufacturing a sound deadening hose according to the invention of claim 2, in the mold closing step, the diameters of two adjacent parts of the parison are reduced to form an outer peripheral surface of the connecting end part of the extension hose. It is not necessary to use a clamp because the hose and the muffling expansion chamber are connected to the extension hose by binding the hose in a circumferential shape.

[0009]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments in which the present invention is applied to an air cleaner hose for an intake system of an internal combustion engine will be described below with reference to the drawings.

First, FIGS. 1 to 6 show a method of manufacturing the muffling hose 1 according to the first embodiment. The sound deadening hose 1 manufactured by this method is of a type in which extension hoses are connected to both ends of the sound deadening hose after manufacturing, and it was manufactured in the following process order.

[Hose Forming Step] As shown in FIG.
An air cleaner hose 2 made of synthetic resin was formed by blow molding, and four silencer communication holes 3 were formed in the center of the air cleaner hose 2 by machining. The air cleaner hose 2 can also be formed by injection molding, extrusion molding or the like.

[Mold Setting Step] As shown in FIGS. 1 and 2, plug members 4 were inserted into both ends of the air cleaner hose 2. The plug member 4 includes a plug tube portion 5 that is externally inserted on the outer circumferences of both ends of the air cleaner hose 2, and a support pin portion 6 that is inserted on the inner circumferences of both end portions of the air cleaner hose 2.
It is composed of a base portion 7 connecting the both portions 5 and 6, and a shaft portion 8 protruding from the base portion 7, and is made of a highly rigid metal material. By inserting the support pin portion 6 into the inner circumference of the air cleaner hose 2, centering can be performed. The shaft portion 8 is gripped by a slide mechanism (not shown), the air cleaner hose 2 and the plug member 4 are opened, and the blow split mold 10 is opened.
It was arranged by sliding it from below during 10 minutes. The blow split molds 10 and 10 have a concave molding surface 11 and a bite 1 respectively.
2, and is supported so that it can be opened and closed in the lateral direction.

[Parison Extrusion Process] As shown in FIG. 2, on the outer periphery of the air cleaner hose 2 and the plug pipe portion 5,
A cylindrical parison 14 made of molten resin was extruded from the crosshead 13 of the upper extruder.

[Mold Closing Step] As shown in FIG. 3, by closing the blow split molds 10 and 10, two separate locations 15 and 15 of the parison 14 at the bite parts 12 and 12 of the blow split molds 10 and 10. Was reduced in diameter to be tightly bound to the outer peripheral surface of the air cleaner hose 2 in a circumferential shape, and the burr portions 16 and 16 at both ends of the parison 14 were mounted on the outer peripheral surface of the plug tube portion 5.

[Air Blowing Step] As shown in FIG. 4, air is blown into the parison 14 through the air flow passage 9 formed in the lower plug member 4 and the muffler communication hole 3 to remove the parison 14. The space between the two parts 15 and 15 is expanded and pressed against the concave molding surface 11, and the sound expansion chamber 17
Was molded.

[Burr Cutting Step] After the parison 14 is cooled and hardened, the blow split molds 10 and 10 are opened to remove the air cleaner hose 2 and the like, and the parison 1 is removed as shown in FIG.
The burr portions 16, 16 at both ends of No. 4 were cut off from arbitrary positions.
In the present embodiment, by cutting at the arrow positions in the figure, only the edge portions 16a, 16a of the burr portions 16, 16 where the shape tends to undulate are cut off, and the burr portions 16, 16 at both ends are cut.
The rest was left as part of the product. As described above, the muffling hose 1 as shown in FIGS. 5 and 6 was completed. afterwards,
As shown in FIG. 5, the ends of the extension hose 18 were externally attached to the outer peripheries of both ends of the air cleaner hose 2 and tightened with a wire clamp 19 for connection.

According to the first embodiment configured as described above, the burr portions 16 on both ends of the parison 14 are formed in the mold closing step.
Since the plug 16 is mounted on the outer peripheral surface of the plug pipe portion 5, the both-end burr portions 16 and 16 are not attached to both end edges of the outer peripheral surface of the air cleaner hose 2. Therefore, the dimension and shape accuracy of both ends of the outer peripheral surface of the air cleaner hose 2 do not deteriorate,
Of course, it is not necessary to finish the both ends. Then, the extension hoses 18 can be accurately connected to the both ends. Also,
Both ends burr parts 16 and 16 can be cut from any appropriate position, and the cutting marks do not affect the size and shape accuracy of both ends of the air cleaner hose 2. Therefore, the cutting is not required to be accurate, and the cutting work does not take time. .

Next, FIGS. 7 to 12 show a method of manufacturing the muffling hose 20 according to the second embodiment. The sound deadening hose 20 manufactured by this method is
It is a type in which the extension hose 21 is connected at the time of blow molding, and was manufactured in the following process order.

[Hose Forming Step] Similar to the same step of the first embodiment, the air cleaner hose 2 as shown in FIG. 7 was formed, and further two extension hoses 21 were formed. A large number of circumferential projections 22 are formed on the outer peripheral surface of the extension hose 21 at small intervals.

[Mold Setting Step] As shown in FIGS. 7 and 8, the connection ends 23 of the extension hose 21 are externally fitted to the outer peripheries of both ends of the air cleaner hose 2, and the first embodiment is provided at both ends of the extension hose 21. A plug member 4 similar to the above was inserted. At this time, part of the connection end 23 is exposed,
The plug tube portion 5 was externally attached to the outer circumference of the extension hose 21. The shaft portion 8 was gripped by a slide mechanism (not shown), and the air cleaner hose 2, the extension hose 21, and the plug member 4 were arranged between the opened blow split dies 10, 10 by sliding them from below.

[Parison Extrusion Process] As shown in FIG. 8, a cylindrical parison 14 made of molten resin is provided on the outer periphery of the air cleaner hose 2, the extension hose 21, and the plug pipe portion 5 from the crosshead 13 of the upper extruder. I pushed it out.

[Mold Closing Step] As shown in FIG. 9, by closing the blow split molds 10 and 10, two separate portions 15 and 15 of the parison 14 are separated by the biting parts 12 and 12 of the blow split molds 10 and 10. To reduce the diameter of the air cleaner hose and tightly bind it to the outer peripheral surface of the air cleaner hose 2.
The adjacent portions 24, 24 of 15 are reduced in diameter to be tightly bound to the outer peripheral surface of the connecting end portion 23 of the extension hose 21 in a circumferential shape, and the burr portions 16, 16 at both ends of the parison 14 are mounted on the outer peripheral surface of the plug tube portion 5. Let

[Air Blowing Step] As in the same step of the first embodiment, as shown in FIG. 10, the muffling expansion chamber 17 was molded by blowing air into the parison 14.

[Burr Cutting Step] Similar to the step of the first embodiment, after the parison 14 is cooled and hardened, the blow split molds 10 and 10 are opened to release the air cleaner hose 2 and the like, and as shown in FIG. The edge portions 16a, 16a of the burr portions 16, 16 at both ends were cut off. As described above, the muffling hose 20 as shown in FIGS. 11 and 12 was completed.

According to the second embodiment configured as described above, the same effect as that of the first embodiment can be obtained. Further, in the mold closing process, the diameters of the adjacent portions 24, 24 of the two locations 15, 15 of the parison 14 are reduced and tightly bound to the outer peripheral surface of the connecting end portion 23 of the extension hose 21 in a circumferential manner, so that the air cleaner hose 2 and Since the silencing expansion chamber 17 and the extension hose 21 are connected, it is not necessary to use a clamp. In particular, in this embodiment, the circumferential protrusion 22 is formed on the outer peripheral surface of the connection end 23.
(Other protrusions or protrusions composed of protrusions may be provided.) The peripheral protrusions 22 are provided with the adjacent portion 2 of the parison 14 to be tightly bound.
Since 4 is locked, the connection strength is high.

The present invention is not limited to the configuration of the above-described embodiment, and may be embodied with appropriate modifications, for example, as follows, without departing from the spirit of the invention. (1) In the above-described embodiment, the burrs on both ends are cut off mainly for the sake of appearance. Therefore, if the appearance of the burrs on both ends is not a problem or an obstacle, the cutting operation may be omitted. Good. (2) In addition to air cleaner hoses, specify hoses for various applications where noise is a problem.

[0027]

As described in detail above, according to the method of manufacturing a muffling hose according to the invention of claim 1 of the present application, when the muffling expansion chamber is formed by blow molding on the outer periphery of the hose having the muffling communication hole. In addition, the burrs on both ends of the parison can be prevented from adhering to both edges of the hose to improve the size and shape accuracy of both ends of the hose, and the cutting work of the burrs on both ends of the parison can be omitted or simplified. Therefore, the cost can be reduced.

In addition to the above effects, according to the method of manufacturing a sound deadening hose according to the invention of claim 2, extension hoses can be connected to both ends of the hose at the time of the blow molding without using a clamp, thereby reducing the cost. Can be achieved.

[Brief description of drawings]

FIG. 1 is an exploded perspective view showing an air cleaner hose and a plug member according to a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a mold setting process in the same embodiment.

FIG. 3 is a cross-sectional view showing a mold closing step in the same embodiment.

FIG. 4 is a cross-sectional view showing an air blowing step in the same embodiment.

FIG. 5 is a cross-sectional view showing a burr excision step in the same embodiment.

FIG. 6 is a perspective view showing a sound deadening hose manufactured according to the same embodiment.

FIG. 7 is an exploded perspective view showing an air cleaner hose, an extension hose, and a plug member according to a second embodiment of the present invention.

FIG. 8 is a cross-sectional view showing a mold setting step in the same embodiment.

FIG. 9 is a cross-sectional view showing a mold closing step in the same embodiment.

FIG. 10 is a cross-sectional view showing an air blowing step in the same embodiment.

FIG. 11 is a cross-sectional view showing a burr excision step in the same embodiment.

FIG. 12 is a perspective view showing a sound deadening hose manufactured according to the same embodiment.

FIG. 13 is a cross-sectional view showing a method for manufacturing a conventional sound deadening hose.

FIG. 14 is a cross-sectional view showing a sound deadening hose manufactured by the same conventional method.

[Explanation of reference numerals] 1 muffling hose 2 air cleaner hose 3 muffling communication hole 4 plug member 5 plug tube part 10 blow split type 11 concave molding surface 12 biting part 14 parison 15 two places 16 both ends burr part 17 muffling expansion chamber 20 Noise reduction hose 21 Extension hose 23 Connection end 24 Adjacent part

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hidetoshi Ishihara, No. 1 Nagahata, Ochiai, Kasuga-cho, Nishikasugai-gun, Aichi Toyoda Gosei Co., Ltd. Toyoda Gosei Co., Ltd.

Claims (2)

[Claims] 1. A step of externally inserting a plug pipe around both ends of a hose having a muffler communication hole, and setting the hose and the plug pipe between open blow split molds, and the outer periphery of the hose and the plug pipe. And a step of extruding a cylindrical parison made of molten resin, and by closing the blow split mold, the two separate parts of the parison are reduced in diameter by the cutting portion of the blow split mold to surround the outer peripheral surface of the hose. While tightly binding the parison, a step of riding the burr portions at both ends of the parison on the outer peripheral surface of the plug pipe, and by blowing air into the parison through the sound deadening communication hole, the two portions of the parison are expanded. And a method of manufacturing a sound deadening hose, the method including molding a sound deadening expansion chamber. 2. A plug pipe is attached to the outer circumference of the extension hose such that the connection ends of the extension hose are externally inserted to the outer circumferences of both ends of the hose having the noise-supplementing communication hole, and a part of the connection end is exposed. Extrapolating, setting the hose between the open blow split mold, the extension hose and the plug pipe, and extruding a cylindrical parison made of molten resin on the outer periphery of the hose, the extension hose and the plug pipe, By closing the blow split mold, the two separate parts of the parison are reduced in diameter by the erosion part of the blow split mold to be tightly bound circumferentially on the outer peripheral surface of the hose, and the adjacent part of the two parts of the parison is bound. The diameter of the extension hose is circumferentially tightly bound to the outer peripheral surface of the connecting end portion, and the burr portions at both ends of the parison are mounted on the outer peripheral surface of the plug pipe; A method of manufacturing a sound deadening hose, comprising the step of expanding the space between the two parts of the parison by blowing air into the parison to form a sound deadening expansion chamber.