Ⅰ.The use of hydraulic hose standards for the construction machinery industry:
The main domestic standards are:
—— Domestic rubber hose: Enterprise standards (manufacturers), GB/T 3683, GB/T 10544, ISO 1436, ISO 3862, SAE J517, EN 853 and EN 856.
- Imported hoses: ISO 1436, ISO 3862, SAE J517, EN 853 and EN 856.
At present, the most widely adopted standards for foreign wire braided winding hydraulic hoses are ISO 1436, ISO 3862, SAE J517, EN 853, and EN 856. These standards have a safety factor of 4 and foreign countries strictly follow the standards in their use. The requirements are very standard, so the service life is long and the quality of use can be guaranteed.
GB/T 3683-2011/ISO 1436:2009 Introduction:
ISO 1436:2009, revised and implemented in 2009, is a combination of SAE J517 and EN 583 with the same dimensions, but the pressure is based on
EN 853. There are 6 series:
——1ST type: hose with single steel braid and thick outer cover
——2ST type: hose with two layers of steel wire braid and thick outer cover
——1SN and R1ATS type: hose with single steel braid and thin outer cover
——2SN and R2ATS type: hose with two layers of steel braid and thin outer cover
Introduction to GB/T 10544 and ISO 3862:2009:
ISO 3862:2009, revised and implemented in 2009, is a collection of 4 series of the R12, R13, and R15 series of SAE J517 and the 4SP and 4SH series of EN 856. There are a total of five series:
——4SP type: 4-layer wire wound medium pressure hose
——4SH type: 4-layer wire wound high pressure hose
—— R12 type: 4-layer wire wound high temperature medium pressure hose
—— R13 type: multi-layer steel wire wound high temperature and high pressure heavy-duty hose
——R15 Type: Multilayer Steel Wire Winding High Temperature Ultra High Pressure Heavy Duty Hose
Ⅱ.The construction machinery industry uses the characteristics of hydraulic hose
1. The space is narrow, resulting in a small bend radius of the pipeline, which is easy to rub against each other and damage the hose.
2. high working pressure, the pipeline has a certain impact load;
3. dynamic use, pipelines often need to do bending motion;
4. the system vibration, can easily cause early damage to the hose;
5. The temperature of the conveying medium is high and the environment is poor;
6. the system pressure change frequency is high, the pulse performance requirements are high.
Ⅲ.The construction machinery industry using hydraulic hose precautions
1.Hydraulic hoses and hose assemblies have a limited life span, including reduced life factors including
a. Bending to less than the minimum bending radius;
b. twisting, stretching, bending, rolling or abrasion hoses;
c. Use above the maximum temperature or below the minimum temperature;
d. The hose is used under a pulse exceeding the maximum working pressure;
e. The quality of the joints, buckle quality;
2. The use of hydraulic hose
a. The pressure in the hose (including pulse pressure) must not exceed the specified maximum working pressure;
b. The hose shall not be used outside the specified or recommended temperature range (including the temperature of the material being conveyed and the ambient temperature);
c. The hose can only be used to convey the medium specified by its design;
d. The hose should not be used under the specified minimum bending radius, otherwise it will restrict the passage of the conveyed material and reduce the service life. Should avoid bending or twisting near the hose joints, the bending of these parts will make the reinforcement of the hose fatigue damage, so that premature hose damage;
e. The hose must not be used in a twisted state;
f. The edge of the pipe joint should be smooth, and the dimensions of the core, jacket, etc. should be guaranteed. The amount of buckle must be controlled. Inadequate or excessive can cause premature damage to the assembly.
g. The hose has a limited life and should be checked and replaced regularly.
Ⅳ.The construction machinery industry use hose problems
1. In the design of the complete machine, the requirements of pipeline orientation, minimum bending radius and installation requirements of the hose are not taken into consideration. After the design is completed, it is considered according to the size of the space, resulting in a narrow space, unreasonable pipeline movement, and bending of the hose. Less than the minimum bend radius, installation difficulties and other issues.
2. Improper hose selection:
a. Excessive pursuit of higher labeling pressures while ignoring safety multiples.
The standard hoses used in large quantities in the construction machinery industry are marked with high pressure, but the safety factor is only 2.5 times and it should be 4 times more reasonable.
b. Three-layer steel braided pipe problem
In all the international and foreign advanced standards of hydraulic hoses, there are no three-layer steel wire braided pipe types. For the severe conditions of high pressure and high pulse of construction machinery, wire winding hoses should be used instead.
c. The cloth tube has become a phase-out product due to low material utilization rate and high cost.
3. Failure to use and install in accordance with the standard specification, resulting in early damage and reduced service life.
Ⅴ. Development direction of hydraulic hoses for construction machinery industry
1. Develop Compact Hydraulic Hose
For example SAE 100R16, SAE 100R17 and so on.
2. Develop high pulse performance hoses
High pulse performance up to 1 million times, such as excavator hose.
3. Development of thin outer cover hose
Suitable for use without stripping to increase efficiency.
4. Ultra high pressure hydraulic hose
5. High and low temperature resistant hydraulic hose