GB/T 15622-2005 Hydraulic Fluid Power-Test Method For The Cylinders

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GB/T 15622-2005 Hydraulic Fluid Power-Test Method For The Cylinders

GB/T 15622-2005 Hydraulic Fluid Power-Test Method For The Cylinders

Published by Administration of Quality Supervision, Inspection and Quarantine of People’s Republic of China and Standardization Administration of China in 2015-07-11 and Implemented in 2006-01-01.

Foreword

This standard,adopted and modified ISO 10100:2001《Hydraulic Fluid Power-Test Method For The Cylinders》,is a revision of GB/T 15622-1995《Hydraulic Testing Method For The Cylinders》.

This Standard replace GB/T 15622-1995《Hydraulic Testing Method For The Cylinders

The main differences between this standard and ISO 10100:2001 in terms of technical content are listed in Appendix A.

The main changes of this standard compared with GB/T 15622-1995 are as follows:

—In Chapter 2, two reference standards are deleted and two new reference standards are added;

– In the factory test temperature, increase the “factory test allows the temperature to be lowered, in the range of 15 ° C ~ 45 ° C, but the test indicators should be adjusted according to temperature changes, to ensure that the performance standards specified in the product standards can be achieved at 50 ° C ± 4 ° C. ”

– increase “5.2.4 compatibility”;

– increase “6.5.3 leakage test under low pressure”;

– Change the previous versions of “6 Factory Test Items” and “7 Type Test Items” to “7 Type Test” and “8 Factory Test” respectively. The “factory test” does not make a “must test” or “sample test” rule ;

–  Cancel the durability test and add the buffer test in the factory test;

– Add “9 experimental report” and “10 annotation instructions”;

Appendix A and Appendix B of this standard are informative annexes.

This standard was proposed by the China Machinery Industry Federation.

This standard is under the jurisdiction of the National Hydraulic and Pneumatic Standardization Technical Committee (SAC/TC 3).

This standard was drafted: Beijing Institute of Machinery Industry Automation, Harbin Institute of Technology.

The main drafters of this standard: Zhao Manlin, Liu Xinde, Jiang Jihai.

The previous versions of the standards replaced by this standard are:

—GB/T 15622-1995.

Testing Method For The Hydraulic Cylinders

1.Scope

This standard specifies the test method for hydraulic cylinders.
This standard applies to the type test and factory test of hydraulic cylinders (including double-acting hydraulic cylinders and single-acting hydraulic cylinders) with hydraulic oil (liquid) as working medium.
This standard does not apply to combined hydraulic cylinders.

2.Normative reference

The terms in the following documents become the provisions of this standard by reference to this standard. For dated references, all subsequent amendments (not including errata content) or revisions do not apply to this standard. However, encourage the patries who has reached agreements based on  this standard to research if the latest version of these documents can be used. For undated references, the latest edition applies to this standard.

GB/T 14039-2002 《Hydraulic fluid power–Fluids–Method for coding the level of contamination by solid particles》(ISO 4406:1999.MOD)

GB/T 17446《Fluid power systems and components – Vocabulary》(GB/T 17466-1998,idt ISO 5598;1985).

3.Terms and definitions

The definitions given in GB/T 17446 and listed below apply to this standard.

3.1  The Minimum Pressure

3.2  The Cavity With Piston Rod

3.3  The Cavity With Piston Rod

3.4  Load Efficiency

4.Symbols and units

                           The symbols used in this standard and their units are shown in Table 1.

GBT-15622-2005

5.Experimental setup and experimental conditions

5.1 experimental device

5.1.1 Hydraulic cylinder test device is shown in Figure 1 and Figure 2. The schematic diagram of the hydraulic system of the experimental device is shown in Figure 3~5.

GBT-15622-2005

5.1.2 Measurement accuracy

The measurement accuracy is measured in two stages, B and C. The allowable system error of the measurement system should meet the requirements of Table 2.

5.2 Experimental oil

5.2.1 Viscosity

The kinematic viscosity of the oil at 40 ° C should be 29mm2 / s ~ 74mm2 / s.

Note: except for special requirements

5.2.2 Temperature

Unless otherwise specified, the type test shall be carried out at 50 °C ± 2 °C, and the factory test shall be carried out at 50 °C ± 4 °C. The factory test allows the temperature to be lowered, in the range of 15 ° C ~ 45 ° C, but the test indicators should be adjusted according to temperature changes, to ensure that the product specifications can be achieved at 50 ° C ± 4 ° C.

5.2.3 Pollution degree rating

The solid particle contamination level of the test system oil shall not be higher than 19/15 or -/19/15 specified in GB/T 14039.

5.2.4 Compatibility

The experimental fluid should be compatible with the sealing material of the hydraulic cylinder under test.

5.3 stable conditions
In the test, the average display value of each controlled parameter is stable under the range specified in Table 3. The parameters should be measured and recorded under stable conditions.

 

6. Experimental items and test methods
6.1 Test run
Adjust the pressure of the test system so that the hydraulic cylinder under test starts under no load conditions. And reciprocating the whole process several times, completely eliminating the air inside the hydraulic cylinder.
6.2 Starting pressure characteristic test
After the test run, adjust the relief valve under no-load conditions, so that the pressure of the rodless chamber (double piston rod cylinder, both chambers) is gradually increased. When the hydraulic cylinder is started, the starting pressure is recorded as Minimum starting pressure.

6.3 Pressure test
The piston parts of the hydraulic cylinders under test should be stopped at the two ends of the stroke (the single-acting hydraulic cylinder should reach at the stroke limit position), and 1.5 times working pressure should be applied to the working chamber, the type test should be kept for 2 minutes, and the factory test should keep for 10 seconds.

6.4 Durability test
Under the rated pressure, the hydraulic cylinder under test is continuously operated at the highest speed required by the design, and the speed error is ±10%. Continuous operation for more than 8 hours at a time, during the test, the parts of the hydraulic cylinder to be tested shall not be adjusted. Record the cumulative travel.

6.5 Leak test
6.5.1 Internal leakage
The working chamber of the hydraulic cylinder to be tested is put into oil, pressurized to a rated pressure or a user-specified pressure, and the amount of leakage through the piston to the unpressurized chamber is measured.
6.5.2 External leakage
When performing the tests specified in 6.2, 6.3, 6.4, and 6.5.1, check the leakage of the piston rod seal; check for leaks at each static seal, joint surface and adjustable mechanism of the cylinder.
6.5.3 Leak test under low pressure
When the inner diameter of the hydraulic cylinder is greater than 32 mm, the lowest pressure is 0.5 MPa (5 bar); when the inner diameter of the hydraulic cylinder is less than 32 mm, at a pressure of 1 MPa (10 bar). Reciprocate the hydraulic cylinder for more than 3 times, and stay at the end of the stroke for at least 10s each time.
The following tests were performed during the course of the experiment:
a) Check if the hydraulic cylinder vibrates or crawls during the movement
b) Observe the oil leak at the piston rod seal. When the experiment is over, the oil film appearing on the piston rod should not be sufficient to form oil droplets or oil rings;
c) Check all static seals for oil leaks;
d) Check the throttle and the cushioning components installed in the hydraulic cylinder for oil leakage;
e) If the hydraulic cylinder is welded, check the weld seam for oil leakage.

6.6 Buffer test
The buffer valve of the working chamber of the tested hydraulic cylinder is completely loosened, the test pressure is adjusted to 50% of the nominal pressure, and run the hydraulic cylinder with the maximum designed speed to detect the buffering effect when running until the buffer valve is fully closed.

6.7 Load efficiency test
Install the dynamometer on the piston rod of the hydraulic cylinder under test, keep the hydraulic cylinder under test running at a constant speed, calculate the load efficiency under different pressure according to the following formula, and draw the load efficiency characteristic curve, as shown in Figure 6.

6.8 High temperature test
At rated pressure, the working fluid of 90 °C should be input to the hydraulic cylinder under test, and the full stroke was reciprocated for 1 h.
6.9 Itinerary inspection
The piston and the plunger of the hydraulic cylinder to be tested were stopped at the extreme positions of both ends of the stroke, and the stroke length should be  measured.

7. Type test
Type testing should include the following items:
– commissioning (refer to 6.1);
– starting pressure characteristic test (refer to 6.2);
– withstand voltage test (refer to 6.3);
– leak test (refer to 6.5);
– buffer test (refer to 6.6);
– load efficiency test (refer to 6.7);
– high temperature test (when required for the product)) (refer to 6.8);
– durability test (refer to6.4);
– itinerary inspection (refer to 6.9)…

8. Factory test
The factory test should include the following items:
– commissioning (Ref. 6.1);
– start pressure characteristic test (refer to 6.2);
– withstand voltage test (Ref. 6.3);
– leak test (refer to 6.5);
– buffer test (Ref. 6.6);
– the itinerary test (refer to 6.9);

9. Experimental report

The experimental data should be recorded in detail in the experimental process. A complete experimental report should be completed after the test. The format of the experimental report is shown in Table 4.

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