JPS63285389A - Tube made of high molecule for automobile - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a synthetic resin vibrator suitable for forming a liquid conduit for an automobile.

(Prior art and its problems) Metal pipes are used to transfer fuel for automobiles and refrigerant for automobile coolers, but they not only require bending in advance to match the piping route, but also have trouble connecting to the main body. Since this requires a joint member, there is a problem in that construction is time-consuming.

In order to solve these problems, for large vehicles etc. where the piping can be arranged relatively straight in a plane, we have installed pipes that have excellent oil resistance, crack resistance and mechanical strength, as well as high flexibility. Tubes made of nylon 11 or nylon 12 are used in some cases.

With such a tube, it is not only possible to pipe a simple route without requiring pretreatment by taking advantage of its elasticity, but also without using a special joint member due to the elasticity of the tube itself. It can be connected to the main body, making it possible to reduce construction costs.

However, in cars where piping space is limited, such as small cars, it is necessary to bend the piping in a three-dimensional manner with a small radius of curvature, which can lead to buckling if the bending process is not performed in advance. Not only is this a problem, but even if bending is done, the shape of long objects like fuel pipes cannot be fixed independently due to their high elasticity, making it more labor-intensive to construct. In addition to the problem of having to prepare a mold that can be bent each time,
There is a problem in that the equipment is expensive.

In order to solve this problem, it may be possible to add a large amount of plasticizer to Nylon 1 or Nylon 12, but this would reduce the strength, make it more likely to buckle, and limit the bending radius. rupture pressure may decrease,
There is a problem that the permeability of gasoline, freon, etc. increases by several tens to hundreds of times, and furthermore, there is a risk that the dimensions will change due to volatilization of the plasticizer and the connection will come off.

(Means for Solving the Problems) The present invention was made in view of the above-mentioned circumstances, and its purpose is to improve the chemical properties of nylon 11, nylon 12, and nylon 612. An object of the present invention is to provide a polymer tube for automobiles that makes good use of its mechanical properties and allows easy piping work.

That is, the present invention is characterized by the fact that nylon 1]
, nylon 12, and nylon 612, and has an outer diameter of 5 mmφ to 20 mm.
A tube consisting of a straight section with a diameter of mmφ and a wall thickness of 1/20 to 115 times the outer diameter, the tube has a bellows section in all or a plurality of regions other than both ends, and the bellows section is , the wall thickness is 1/4 to 3/2 times the wall pressure of the straight pipe part, and the pitch is
The groove is 1/20 to 11 times the outer diameter of the peak, the outer diameter of the trough is 1/3 to 1 times the outer diameter of the straight pipe, and the outer diameter of the peak is 1/20 to 11 times the outer diameter of the straight pipe. The point is that it is 2/3 to 3/2 times as large.

Therefore, the details of the present invention will be explained below based on one illustrated embodiment.

FIG. 1 shows one embodiment of the present invention, and the reference numeral 1 in the figure is a tube characterized by the present invention, made of nylon 11
It is made of nylon 12, or nylon 612, and is designed to ensure a sufficient flow rate to enable the engine and cooler to operate.
In the following, straight pipe parts 2.2 having a wall thickness dt of 1/20 times or more and 115 times or less of the outer diameter are provided at both ends, and parts other than both ends have the shape of an automobile (combined with bellows parts 3.3. 3...
. . . are formed at multiple locations with straight pipe portions 2 interposed therebetween.

Nylon 11 in the present invention is polyaminoundecanoic acid, and nylon 12 is polylauryllactam,
or polyaminododecanoic acid, which is nylon 61
2 is polyhexane methylene dodecamide. In addition, nylon 11, nylon 12, and nylon 612 may also be copolymerized with 20% by weight or less of a nylon monomer such as caprolactam or adipic acid hexamethylene diamine salt in addition to the above monomers (in the case of nylon 12, nylon 1
It goes without saying that nylon 11 and nylon 612 monomers can also be used as copolymerization monomers, and the same can be said for other nylon 11.612).
In addition, 40% by weight or less of a modifying monomer such as polytetramethylene glycol or polyolefinic acid having functional groups at both ends may be copolymerized, or a plasticizer for nylon such as butylbenzenesulfonamide or parahydroxyoctylbene sheet may be copolymerized. It may contain up to 20 parts by weight per 100 parts by weight, it may further contain up to 30% by weight of rubber, elastomer, etc., it may also contain pigments and stabilizers.

Further, the nylon 11.12.612 used in the present invention has a relative viscosity of 1.5 to 3.0 at 25°C in a 0.5% metacresol solution.

FIG. 2 shows an embodiment of a processing device for forming the above-mentioned bellows portion 3. In the figure, a core metal 11 has an outer diameter that can be inserted into the straight pipe portion 2, and a forming device for forming the bellows portion 3. The spiral groove 11a is formed to have the depth of the bellows part 3 and a pitch roughly matching the bellows part 3. On the other hand, on the outside of this core metal 11, rollers 12, 12, 12 having grooves 12a formed on the outer periphery that can push a straight tube into the spiral groove 11a are disposed at equal intervals so as to be able to approach and separate. It is configured to be rotationally driven by a drive source.

In this insertion, the core metal 11 is inserted into the tube up to the point where the bellows is to be formed, and the tube is rotated by applying elastic pressure to the surface while heating the straight tube to the extent that it becomes soft. 11 and roller 12.12.12
At the stage where the bellows of a predetermined length has been formed in this way, the roller 12 is moved to the core metal 1.
1, remove the core bar 11 while pulling the tube, and perform the same processing on the next location.

Next, the dimensions of the straight pipe portion 2 and the bellows portion 3 of the tube 1 described above will be explained.

1 even if the pitch of the bellows part 3 is less than 1/20 times the outer diameter.
Even if it is more than twice as large, the bending radius of the tube cannot be made too small.

The outer diameter φ2 of the valley portion 3a of the bellows portion 3 is the outer diameter φ1 of the straight pipe portion 2.
The outer diameter φ3 of the peak portion 3b is 2/3 times or more and 3/2 times or less of the straight pipe portion outer diameter φ1,
Preferably, the middle outer diameter of the trough is 1/2 of the straight pipe outer diameter φ1.
It is desirable that the outer diameter φ3 of the peak portion is approximately equal to the outer diameter φ□ of the straight pipe portion 2, which is greater than or equal to 2/3 times and less than 2/3 times.

This means that the outer diameter φ2 of the valley portion is 1/3 of the outer diameter φ1 of the straight pipe portion 2.
If it is less than double, the inner diameter will become too thin and the flow resistance will be large. On the other hand, if it is more than one time, the outer diameter Φ3 of the peak forming the bellows part 3 will become too large and the straight pipe part 2 will float from the chassis. This makes it difficult to fix.

On the other hand, the outside diameter φ3 of the peak part of the bellows part 3 is 2 of the outside diameter φ1 of the straight pipe part.
If it is less than 73, the diameter of the valley part to obtain the bellows part 3 will be too small, and if it is more than 3/2, the outer diameter of the bellows part 3 will become too thick, and only that part of the piping route where the tube should be accommodated will be used. When it becomes necessary to change the dimensions, etc., and when connecting tubes for brakes, etc. together, there are disadvantages such as the large outer diameter part getting in the way, and generally the bellows part 3 is As the wall thickness of the bellows tends to decrease, the bursting pressure of the three peaks of the bellows portion will decrease significantly.

If the wall thickness d1 of the straight pipe part 2 is less than 1/20 times the outer diameter of the straight pipe part, there is a problem that the withstand pressure will be low and the reliability for automobiles will be lacking.On the other hand, if the wall thickness d1 is 115 times or more There is a problem that not only is the material required unnecessarily, but the outer diameter of the tube becomes unnecessarily thick.

The wall thickness d2 of the roughly bellows portion 3 is equal to 1 of the wall thickness d1 of the straight pipe portion 2.
/4 times or more and 3/2 times or less, preferably 2/3 times or more and 1 time or less.

This means that the wall thickness d2 of the bellows portion 3 is 1/1/1 of the wall thickness dL of the straight pipe portion.
When it is 20 times or less, the pressure resistance is low, and when it is 3/2 or more, the bellows part 3 not only becomes difficult to bend, but also has a problem that the outer diameter becomes too thick and the inner diameter becomes too thin.

Roughly speaking, the length of one tube should be 10M or less as long as it is enough to cover the length of the fuel transportation route of a car, and if it is this long, it is relatively easy to make bellows from both ends. Can be done.

Of course, it is also possible to cut and pipe a continuous tube with a bellows part on site.

When forming a fuel transfer line using the tube 1 configured in this way, when one end of the tube 1 is inserted into the joint member of the fuel tank, a liquid-tight connection is established due to the elasticity of the straight pipe section 2. be done. Thereafter, the bellows part 3 is placed along the chassis so as to lie at the bent part of the piping route, and the tube 1 is then bent around the bellows part 3 in accordance with the pipe route. Thereby, the tube 1 changes its shape three-dimensionally with the smallest possible radius of curvature without buckling due to the flexible flexibility of the bellows portion 3.

Thereafter, by repeating this operation each time the pipe contacts a bend in the route, the piping can be formed more freely.

When the piping is completed, the straight pipe section 27a at the other end of the tube 1 is inserted into the suction port of the fuel pump, and the piping is completed.

Even if the tube 1 that is connected in this way expands or contracts due to temperature changes or is subjected to forces such as vibrations, the elasticity of the bellows part 3 absorbs these forces, so the connections at both ends are It does not become such that an unreasonable force acts on it.

In addition, depending on the transfer fluid, i.e., fuel such as gasoline, alcohol, gasohol, light oil, etc. and its vapor, and the refrigerant of the cooler (fluorinated hydrocarbons used in this case and its vapor), even if the tube length changes, the bellows 3 absorbs dimensional changes due to its elasticity, so the tube does not bend or sag.

In this embodiment, the pipe is cut to a predetermined length before use, but it may be cut at the time of construction according to the length of the piping route.

In addition, in this embodiment, the bellows portion 38 is formed separately in multiple locations to match the structure of the automobile, but it is clear that the same effect can be achieved even if the bellows portion is formed continuously other than at both ends. It is.

Generally speaking, in this embodiment, the bellows are formed on the straight tube by post-processing, but the bellows can be added at the same time when the straight tube is formed. can be achieved.

Generally speaking, in this embodiment, the bellows is formed by roller processing, but it may also be formed by other processing methods such as blow processing.

[Example 1] Nylon 11 (manufactured by Toshi Co., Ltd.) (Rilsan BESNO
TL, relative viscosity 1.89), inner diameter 6 mm, outer diameter 8
mm tube, the outer diameter of the peak part is 8.0 mm, and the outer diameter of the valley part is 5.0 mm.
A tube having a total length of 200 mm and having a bellows portion of approximately 100 mm with a diameter of 0 mm, a minimum wall thickness of 0.6 mm, and a pitch of 3.0 mm, and having straight pipe portions of 50 mm at each end was used for the test.

By winding this tube around mandrels of different diameters, we determined the minimum radius of curvature at which buckling occurs.

One end of this tube was sealed with a bamboo joint, and the other end was connected to a water pressure pump to determine the pressure until it burst.

Also, fill the tube with gasoline, seal both ends with bamboo joints, and place it in an oven at 50°C.
After leaving it for a week, the amount of gasoline permeated was determined from the weight loss.

On the other hand, for comparison, the same tube without the bellows part 3 was also tested under the same conditions.

[Example 2] A straight tube with an inner diameter of 6 mm and an outer diameter of 8 mm made of nylon 12 (manufactured by Daicel-Hüls Co., Ltd.) (Diamide L-2140, relative viscosity 2.15) was coated with a crest outer diameter of 8 mm.
0mm, trough outer diameter 5.5mm, minimum wall thickness 0.7mm, pitch 3.0mm, approximately 100mm of bellows part, and 50mm straight pipe parts at both ends, total length 200m.
m tube and a tube without bellows as described in Example 1.
A comparative test was conducted under the following conditions, and the results shown in Table 2 were obtained.

[Example 3] A straight tubular tube with an inner diameter of 6 mm and an outer diameter of 8 mm, made of nylon 12 kneaded with 5 parts by weight of butylbenzenesulfonamide as a plasticizer per 100 parts by weight, has a peak outer diameter of 7.9 mm and a trough outer diameter. Outer diameter 5.5mm, minimum wall thickness 0.8mm
, a bellows part 3 having a pitch of 3.0 mm and a length of about 100 mm, and a straight pipe with 5 mm at each end having a total length of 20 mm.
When a tube with 0 resistance and a straight tube without IllI were tested under the conditions of Example 10, the results shown in Table 3 were obtained.

From these results, the outer diameter of nylon 11 and nylon 12 is 5 mm or more and 20 mm or less, and the wall thickness is 1/1/2 of the outer diameter.
A tube consisting of a straight pipe part of 20 times or more and 115 times or less, which has a bellows part in all or multiple regions other than both ends, and whose wall thickness is 1/4 times or more the wall thickness of the straight pipe part. 3/
2 times or less, the pitch is 1/20 to 1 times the outer diameter of the ridge, the outer diameter of the trough is 1/3 to 1 times the outer diameter of the straight pipe, and the pitch is 1/20 to 1 times the outer diameter of the ridge, and The diameter is 2/3 or more times the outer diameter of the straight pipe 3/
It was confirmed that by forming a bellows portion that is twice as large or less, it is possible to reduce the radius of curvature to 1/3 or less while minimizing the permeation amount of volatile oil such as gasoline and the decrease in bursting pressure.

In addition, when a similar test was conducted using nylon 612 (stiff), the same results as for the above-mentioned nylon 11.12 were obtained.

(Effects) As explained above, according to the present invention, one selected from nylon 11, nylon 12, and nylon 612 is used.
Made of polymeric material with an outer diameter of 5mmφ to 20mm
A tube consisting of a straight part with a diameter of φ and a wall thickness of 1/20 to 115 times the outer diameter, the tube has a bellows part in all or multiple regions other than both ends, and the bellows part is , the wall thickness is 1/4 to 3/2 times the wall pressure of the straight pipe part, the pitch is 1/20 to 1 time the outer diameter of the ridge part, and the outer diameter of the trough part is the outer diameter of the straight pipe part. Since the outer diameter of the ridge is 2/3 to 3/2 times the outer diameter of the straight pipe part, it has excellent blocking properties for volatile liquids that are transferred, weather resistance, and durability. Made of nylon 1]
While maintaining the excellent properties of Nylon 12 and Nylon 612, the minimum bending radius required for automotive piping can be applied at any time during construction, and piping work can be performed without the need for special joint members. .

[Brief explanation of drawings]

Figure 1 is a perspective view showing one embodiment of the present invention, Figure 2 (A)
(B) is a cross-sectional view and a front view showing one embodiment of bellows-forming snowmaking, respectively, and FIG. 3 is an explanatory diagram showing the dimensions of the straight pipe portion and the bellows portion 3. 1...Tube 2...Straight pipe section 3...Bronze part Figure 1 Figure 3 Figure 2 (A) (B)

Claims (1)

[Claims] Made of one type of polymer material selected from nylon 11, nylon 12, and nylon 612, with an outer diameter of 5 m.
mφ to 20mmφ, and the wall thickness is 1/20 to 1 times the outer diameter.
/ A tube consisting of a straight pipe part of 5 times, which has a bellows part in all or multiple regions other than both ends of the tube,
The wall thickness of the bellows portion is 1/4 to 3/2 of the wall thickness of the straight pipe portion.
double, the pitch is 1/20 to 1 times the outer diameter of the peak, the outer diameter of the valley is 1/3 to 1 times the outer diameter of the straight pipe, and the outer diameter of the peak is 1/20 to 1 times the outer diameter of the straight pipe. A polymer tube for an automobile, characterized in that the outer diameter is 2/3 to 3/2 times the outer diameter of the tube.