JPH08219961A - Brake hose pressure resistance test equipment - Google Patents

Abstract

PURPOSE: To obtain a withstanding pressure test equipment for brake hose having a function for detecting the defect of a product after the withstanding pressure test in which the productivity can be enhanced by decreasing the number of test steps. CONSTITUTION: The withstanding pressure test equipment for brake hose comprises a high pressure test system 28 for detecting a defect (e.g. inflation of outer surface) caused by leakage on the outer surface side of a brake hose 4, and a low pressure test system 39 for detecting inflation of inner surface. Each of the high pressure test system 28 and the low pressure test system 39 comprises branch piping communicating a hose 4 to be tested and a master sample 5 having same structure as the hose 4. A differential pressure sensor 24 for high pressure airtightness test is inserted between the branch piping 27 of the high pressure test system 28 and a differential pressure sensor 36 for measuring the inside diameter is inserted between the branch piping 37, 38 of the low pressure test system 39. The branch piping of high and low pressure test systems is joined for every hose 4 to be tested and master sample 5 and a valve V1 -V8 is provided for each branch piping. Low and high pressure tests are carried out separately on common piping 40, 41 by switching the valves.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a pressure test device for a brake hose, and more particularly to a device for determining whether the brake hose is acceptable or not, by utilizing a pressure leak caused by a defect leaking to the outer surface side or an inner surface blister. .

[0002]

2. Description of the Related Art Generally, a brake hose is shown in FIG.
As described above, the joint fittings 1 and 2 are fastened to both ends of the hose body 3, and the hose body 3 includes the inner layer 10 and the reinforcing thread layer 1
1. The intermediate layer 12, the reinforcing yarn layer 13, and the outer layer 14.
The inner layer 10, the middle layer 12 and the outer layer 14 are usually made of rubber. The brake hose 4 having such a structure is completed by fastening joint fittings, and then a pressure resistance test is performed on all the finished products to determine whether they pass or fail, and those that pass are put on the market.

The pressure resistance test of a brake hose is generally carried out by press-fitting water into the hose and pressurizing the inner surface of the hose under the condition of 300 kgf / cm ² × 3 minutes. In this pressure resistance test, defects that leak to the outer surface side of the hose, in particular, the gap 12 between the pinhole 10a and the intermediate layer 12 generated due to the disorder of the mesh of the reinforcing thread layer 11 during vulcanization of the hose body as shown in FIG.
The outer surface blisters 14a generated by the water pool 14b formed by passing through a were checked visually or by a tentacle during or after the pressurization. Then, after removing water droplets adhering to the inner and outer surfaces of the product, a defect on the inner surface side of the hose body, that is, the reinforcing yarn layer 11 during vulcanization of the hose body as shown in FIG.
In order to detect the inner surface blisters 10c generated by the water pool 10b formed by passing through the pinholes 10a generated due to the disorder of the mesh, a predetermined outer diameter (for example, φ2.00 to φ2.
Passing the finished product by checking whether the inner diameter of the hose is secured to a predetermined size by passing a steel wire having 05) through the entire length of the product or passing a steel ball having a predetermined diameter. Was judged to be an acceptable product.

[0004]

In the test example of the prior art, the pressure resistance test by water pressure requires three steps of work of applying water pressure, dehydration work, and work of checking inner and outer diameters, which is wasteful in terms of production. If the water content in the brake fluid is high when the brake hose is used after it is attached to the vehicle, the vapor lock phenomenon occurs and the braking performance is significantly reduced. Therefore, it is necessary to completely remove the water droplets adhering to the inside of the brake hose after the pressure resistance test by the water pressure, but there is a problem that the water droplets remain when the shape of the fitting is complicated. The blisters that occur inside and outside the hose, and the leaks from the joint fittings are overlooked because they can be checked by the human senses, such as visually and with tentacles.

The present invention solves the above-mentioned problems of the prior art, improves the productivity by reducing the number of test steps, and provides a pressure test device for a brake hose having a function of detecting defects in products after a pressure test. The purpose is to do.

[0006]

A brake hose pressure resistance test apparatus provided by the present invention is a high pressure test system for detecting defects leaking to the outer surface side of a brake hose and a low pressure test system for detecting inner blisters. In both of the high-pressure test system and the low-pressure test system, a hose to be tested and a branch pipe for connecting to a master sample having the same structure as the hose to be tested are provided, and a high-pressure airtight test is provided between the branch pipes of the high-pressure test system. A differential pressure sensor is arranged in communication, and an inner diameter measuring differential pressure sensor is arranged in communication between the branch pipes of the low-pressure test system.

In a preferred embodiment, the branch pipes of both the high-pressure and low-pressure test systems are connected and joined for each test hose and for each master sample, while a valve is provided in any of the branch pipes and the valve is opened or closed by switching. The high pressure test and the low pressure test can be performed separately on a common pipe.

[0008]

[Function] Defects leaking to the outer side of the brake hose and inner blisters are injected into the brake hose with pressure medium, that is, gas from the branch pipes of the high-pressure test system and the low-pressure test system. By checking the pressure difference with the high-pressure airtightness test differential pressure sensor and the inner diameter measurement differential pressure sensor, it is possible to determine whether the test object is acceptable or not. By press-fitting the gas as described above, it is not necessary to dehydrate the brake hose.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 shows a preferred embodiment of a pressure test device for a brake hose according to the present invention.
Is a hose to be tested (see FIG. 2) to be subjected to a pressure resistance test, and 5 is a completed master sample having the same structure as the hose to be tested and having no defects. For these hoses 4 and master sample 5 to be tested, a high pressure test system 28
And a low-voltage test system 39.

The high pressure test system 28 includes a high pressure air source 2
0, a filter 21, a pressure regulating valve 22 and a pressure gauge 23 are provided in one pipe, and branch pipes 26 and 27 are bifurcated from the pipe. High pressure application valves V1 and V2 and stop valves V3 and V4 are provided in front and rear of each branch pipe 26 and 27, and a high pressure airtight test is provided between the branch pipes 26 and 27. A differential pressure sensor 24 for communication is arranged in communication. The connecting portion is a piping portion between the front and rear valves V1 and V3, and V2 and V4.

On the other hand, the low-pressure test system 39 has a single pipe equipped with a low-pressure air generation source 30, a filter 31, a pressure adjusting valve 32 and a pressure gauge 33, and a branch pipe 37 which is bifurcated from the pipe. , 38. Orifices 34 and 35 and stop valves V5 and V6 are provided in front and rear of each branch pipe 37 and 38, and an inner diameter measuring differential pressure sensor 36 is provided between the branch pipe 37 and the branch pipe 38. Have been contacted. The connecting part is a pipe part between the orifice and the valve, that is, between 34 and V5, and between 35 and V6. It is desirable that the pipe of this low-pressure test system has an inner diameter of 6 mm or more in order to reduce the low-pressure air flow resistance in the device pipe.

The high-voltage test system 28 and the low-voltage test system 39 as described above are provided with one branch pipe, that is, 26 and 37, respectively.
27 and 38 are merged, the former 26 and 37 are connected to the common pipe 40 via the hose 4 to be tested, and the latter 27 and 38 are connected to the common pipe 4 via the master sample 5.
By connecting to No. 1, a series of piping system is constructed. V7 is an opening valve provided in the common pipe 40, and V8 is an opening valve provided in the common pipe 41. Further, 25 is a pressure switch and is connected to one branch pipe 26 on the high pressure side.

The operation procedure and test procedure of the pressure resistance test apparatus of the present embodiment having the above-described structure will be described. First, the hose 4 to be tested is connected to the common pipe 40 and the master sample 5 is commonly used. Connect to the pipe 41 and set firmly so that there is no air leakage and prepare for the test.

Then, the high-voltage test system 28 is operated. That is, first, the valves V7 and V6 of the pipes 40 and 41 common to the stop valves V5 and V6 of the low-voltage test system 39,
Keep V8 closed. Next, the high-pressure air obtained by operating the high-pressure air generation source 20 is supplied with the pressure adjusting valve 22.
After being adjusted to the inspection pressure by, the flow is branched into the branch pipes 26 and 27. The branched high pressure air is a valve V for applying high pressure.
1, V2 and stop valves V3, V4, and then applied to the test hose 4 and the master sample 5.

After a predetermined time has passed since the pressure switch 25 reached the inspection pressure, the high pressure applying valves V1 and V2 are applied.
Is closed and the air circuits on the test target hose 4 side and the master sample 5 side are sealed. After a lapse of a predetermined time from the sealing, the pressure difference between the branch pipes 26 and 27 is measured by the high pressure airtightness test differential pressure sensor 24. In the measurement result, when the pressure difference is not recognized, the hose 4 to be tested is passed, while when the pressure difference is recognized, the pressure of the branch pipe 26 communicating with the hose 4 side to be tested is decreased. The hose 4 to be tested at that time is determined to be a defective product.

According to the above high-pressure test, defects that leak to the outer surface side of the hose to be tested, especially outer surface blisters (see FIG. 3).
14a) can be checked.

Next, the low pressure test system 39 is activated.
That is, first, after completing the high pressure test in the previous stage, the open valves V7 and V8 are continuously opened and the stop valves V3 and V4 on the high pressure side are closed. After the high pressure air is exhausted by these operations, the stop valves V5 and V6 on the low pressure side branch pipes 37 and 38 are opened. Then, the low pressure air generation source 30 is operated. The low-pressure air obtained thereby is branched into the branch pipes 37 and 38 after the air pressure is adjusted by the pressure adjusting valve 32. Each branch pipe 3
7 and 38, the flow rate of air is adjusted by the orifices 34 and 35, and the obtained inspection air pressure is applied to the hose 4 to be tested.
And supply to master sample 5. When the air flow is stabilized, the pressure difference between the branch pipes 37 and 38 is measured by the inner diameter measuring differential pressure sensor 36. In the measurement result, when the pressure difference is not recognized, the test target hose 4 is passed, and when the pressure difference is recognized, the test target hose 4 is determined as a defective product. According to this low-pressure test, it is possible to check whether or not an inner surface blister (10c in FIG. 4) has occurred in the hose 4 to be tested.

According to the pressure resistance test apparatus of this embodiment described above, the inspection pressure is applied to the inside of the hose and the inner surface generated after that by only once mounting the brake hose with the joint fittings fastened on the common pipe once. Abnormalities such as blisters and outer blisters can be detected.

[0019]

According to the pressure resistance tester for a brake hose according to the present invention as described above, the number of test steps can be reduced by utilizing the gas pressure difference, as compared with the conventional pressure resistance test using water pressure. Can contribute to improved productivity, and
By checking the internal and external defects of the hose with the differential pressure sensor, there is no oversight and no water drops are left in the hose, and quality assurance can be significantly improved. Further, it is possible to have a function of checking for defects (outer surface blisters, etc.) leaking to the outer surface side of the hose and a function for checking blisters on the inner surface of the hose.

Since the test for detecting defects inside and outside the hose, that is, the high pressure test and the low pressure test can be carried out on a common pipe, the structure of the test apparatus can be simplified, the test procedure can be simplified, and the test operation can be performed. Can contribute to the ease of.

[Brief description of drawings]

FIG. 1 is an explanatory view showing an embodiment of a pressure resistance test device for a brake hose according to the present invention.

2A and 2B show an example of a general brake hose, FIG. 2A is an external view of the brake hose, and FIG.

FIG. 3 is an explanatory cross-sectional view of a state where the brake hose has outer blisters.

FIG. 4 is an explanatory cross-sectional view of a state in which the brake hose has an inner blister.

[Explanation of symbols]

1, 2 Joint fittings 3 Hose body 4 Brake hose; Test target hose 5 Master sample 10 Inner layer 10a Pinhole 10b Inner layer side water pool 10c Inner surface swell 11 Reinforcing thread layer 12 Intermediate layer 12a Gap 13 Reinforcing thread layer 14 Outer layer 14a Outer surface swell 14b Outer layer Side water pool 20 High pressure air source 21 Filter 22 Pressure adjusting valve 23 Pressure gauge 24 High pressure airtight test differential pressure sensor 25 Pressure switch 26, 27 Branch pipe (high pressure side) 28 High pressure test system 30 Low pressure air source 31 Filter 32 Pressure adjustment Valve 33 Pressure gauge 34,35 Orifice 36 Inner diameter measurement differential pressure sensor 37,38 Branch pipe (low pressure side) 39 Low pressure test system 40 Common pipe (test target hose side) 41 Common pipe (master sample side) V1, V2 , V3, V4, V5 6, V7, V8 valve

Claims (2)

[Claims] 1. A high-pressure test system for detecting defects leaking to the outer surface side of a brake hose and a low-pressure test system for detecting inner blisters. Equipped with a branch hose that connects to the target hose and the master sample of the same structure as the test hose, a differential pressure sensor for high pressure airtightness test is connected between the branch hose of the high pressure test system, and the inner diameter between the branch hose of the low pressure test system. Brake hose withstand pressure tester with a measuring differential pressure sensor connected to each other. 2. The structure according to claim 1, wherein the branch pipes of both the high-pressure and low-pressure test systems are connected and merged for each hose to be tested and for each master sample, and an on-off valve is provided in each of the branch pipes. A pressure tester for brake hose that enables high pressure test and low pressure test to be performed separately on a common pipe by switching the open / close valve.