ICS19.060

　　N72

　　case number:

　　JB

　　Machinery Industry Standard of the People's Republic of China

　　JB/T 8763-2001

　　Replace 8763-1998

　　Specifications for electro-hydraulic cement pressure testing machine

　　Specifications for the electro-hydraulic

　　Compression testing machines for cement

　　Released on 2001-12-0

　　2002-03-01 Implementation

　　Released by China Machinery Industry Federation

　　Preface This standard replaces JB/T8763-1998 "Technical Specifications for Electro-hydraulic Cement Pressure Testing Machine".

　　Compared with JB/T8763-1998, the main changes of this standard are as follows:

　　——According to the requirements of the new national standard GB/T 17671-1999 "Cement Mortar Strength Test Method (ISO) Method", the range of acceleration speed and the allowable error index (3.2.6 of the 1998 edition and 3.2. 6);

　　--- Increased the test force maintenance time requirements (see 3.3.5);

　　——The acceleration speed error uniformly stipulates one inspection method (the 1998 edition stipulates two), and the calculation formula of the acceleration speed error is revised in the form of absolute error (4.3.3 of the 1998 edition and 4.3.3 of this edition) );

　　——On the premise of keeping the permissible errors and relative resolution of the force measuring system of the testing machine unchanged, the lower limit of the measuring range of the testing machine has been reduced from the originally stipulated "10% of the maximum test force of the testing machine to the limit specified in this standard" 12kN" (4.4.1 of the 1998 edition and 4.4.1 of this edition).

　　This standard was proposed by the National Testing Machine Standardization Technical Committee.

　　This standard is under the jurisdiction of the National Testing Machine Standardization Technical Committee.

　　This standard is drafted by: Zhejiang Jingyuan Machinery Equipment Co., Ltd., Changchun Testing Machine Research Institute.

　　Participated in the drafting of this standard: Wuxi Building Materials Instrument Machinery Factory (now Wuxi Jianyi Instrument Machinery Co., Ltd.), Jinan Shijin Group Co., Ltd., Shanghai Schenck Testing Machine Co., Ltd.

　　The main drafters of this standard: Shi Canliang, Bao Yuxi, Tao Liying, Du Ronglin.

　　The previous releases of the standards replaced by this standard are as follows:

　　——JB/T 8763-1998

　　Specifications for electro-hydraulic cement pressure testing machine

　　1 Scope

　　This standard specifies the technical requirements, inspection methods, inspection rules, signs and packaging of electro-hydraulic cement testing machines.

　　This standard applies to electro-hydraulic cement pressure testing machines (hereinafter referred to as testing machines) with a maximum test force (FN) not greater than 300kN.

　　2. Normative reference documents

　　The clauses in the following documents become the clauses of this standard through the reference of this standard. For dated references, all subsequent amendments (excluding errata content) or revisions do not apply to this standard, however, encourage the parties to the agreement based on this standard to study whether the latest versions of these documents can be used . For undated references, the latest version applies to this standard.

　　GB/T 2611-1992 General Technical Requirements for Testing Machines

　　Inspection of GB/T 16825-1997 tensile testing machine (idt ISO 7500-1)

　　GB/T 17671-1999 Test method for cement mortar strength (ISO method) (idt ISO 679)

　　JB/T 6147-1992 Testing machine packaging, packaging marks, storage and transportation technical requirements

　　3. Technical requirements

　　3.1 Environment and working conditions

　　The testing machine should work normally under the following conditions:

　　a) Within the range of room temperature 10℃~35℃;

　　b) The relative humidity is not more than 80%;

　　c) In an environment where there is no vibration, no corrosive medium and no strong electromagnetic field interference;

　　d) The fluctuation range of the power supply voltage should not exceed ±10% of the rated voltage;

　　e) Correctly installed on a solid foundation with a levelness of 0.2/1000.

　　3.2 Force application system

　　3.2.1 The frame of the testing machine should have sufficient rigidity and test space to facilitate the loading and unloading of samples, standard force measuring instruments and other auxiliary devices.

　　3.2.2 The test machine should apply and remove the test force smoothly without shock and vibration.

　　3.2.3 The centerline of the upper and lower pressure plates of the testing machine should coincide with the centerline of the frame.

　　3.2.4 The working surface of the lower platen should be clearly engraved with concentric circular engraved lines of different diameters or engraved lines at a 90° angle for positioning. The minimum depth and width of the engraved lines shall be subject to easy observation.

　　3.2.5 The working surface of the pressure plate should be smooth and flat, the maximum value of the surface roughness parameter Ra is 0.8μm; the Rockwell hardness of the pressure plate should not be lower than 55HRC.

　　3.2.6 The testing machine should be able to automatically carry out the compression test at a constant acceleration speed. During the whole process of force application, force should be applied to the sample at a speed of 2400N/s±200N/s evenly until failure, meeting the requirements of 9.3 in GB/T 17671-1999.

　　Note: For special cements not specified in GB/T 17671, the acceleration speed shall be in accordance with the provisions of the corresponding cement product standards.

　　3.3 Force measuring system

　　3.3.1 The permissible errors and relative resolution of the force measuring system of the testing machine shall meet the following requirements:

　　a) The maximum permissible value of relative error (q) of indication is ±1%;

　　b) The maximum permissible value of relative error (b) of indication repeatability is 1%;

　　c) The maximum allowable value of the zero point relative error (fo) is ±0.1%;

　　d) The relative resolution (a) of the test machine force indicating device is 0.5%.

　　3.3.2 The force indicating device should be able to indicate the test force value applied to the sample in real time and accurately.

　　3.3.3 The testing machine should be able to accurately indicate the maximum test force value when the sample is broken or before the test force is removed.

　　3.3.4 The force measuring system of the testing machine should have the function of calibration value correction and zero adjustment. After the test force is removed or the indicated maximum test force disappears, the force indication value should return to zero. The relative error of its zero point should meet the requirements of 3.3.1c).

　　3.3.5 The holding time of the test force should not be less than 30s, during which the variation range of the indicated value of the internal force should not exceed 0.2% of the maximum test force of the testing machine.

　　3.3.6 Before using the testing machine, the warm-up time should not exceed 30 minutes, and the zero drift within 15 minutes should be within ±0.2% of the full scale.

　　3.3.7 The testing machine shall adopt electronic force measurement method, and according to the required force measurement unit, it may have a force signal output interface and an interface connected with printing equipment.

　　3.4 Testing machine function

　　The testing machine should be able to independently complete the test force breaking cycle test;

　　a) Cyclic test of test force breaking at a constant acceleration speed;

　　b) It has the function of storing all test results and being able to consult and read the test results;

　　c) It has the function of automatically processing and computing the data in the memory.

　　3.5 Safety protection device

　　3.5.1 The safety protection device of the testing machine should be sensitive and reliable. When the force value exceeds the maximum test force of the testing machine by 2%~10%, the pressure protection device should act immediately and stop adding force.

　　3.5.2 When the sample breaks, the testing machine should immediately stop applying test force to the sample.

　　3.5.3 The testing machine should have a limit protection device. When the working piston reaches the limit position, it should stop rising immediately.

　　3.6 Noise

　　When the testing machine is working, the sound should be normal, and the noise level should not exceed 75dB(A).

　　3.7 Resistance to bumpy transportation performance

　　Under the condition of packing, the testing machine should be able to withstand the bumpy transportation test without damage. After the test, the testing machine should still meet all the requirements of this standard without rest (excluding normal adjustments allowed by the operating procedures).

　　3.8 Assembly quality, electrical equipment, hydraulic equipment and appearance quality requirements

　　Other requirements such as testing machine assembly quality, electrical equipment, hydraulic equipment and appearance quality shall comply with the provisions of 4.2, Chapter 6, Chapter 7 and Chapter 8 of GB/T 2611-1992.

　　4 Inspection methods 4.1 Inspection conditions

　　The testing machine should be inspected under the environmental and working conditions specified in 3.1 of this standard.

　　4.2 Inspection equipment

　　Inspection instruments, measuring tools and inspection tools include:

　　a) Class 0.3 standard force measuring instrument;

　　b) Rockwell hardness tester;

　　c) Surface roughness tester or surface roughness comparison sample block;

　　d) A spirit level of 0.02mm/m;

　　e) sound level meter;

　　f) Percentage stopwatch that can be recorded and memorized in segments;

　　g) wet and dry thermometer;

　　h) General measuring tools and inspection tools.

　　4.3 Exercising of force Examination of the pressure system.

　　4.3.1 During the process of applying and removing the test force, observe and inspect 3.2.1, 3.2.2, 3.2.3, 3.2.4 of this standard.

　　4.3.2 Use a surface roughness tester or a surface roughness comparison sample to test the surface roughness of the pressure plate; use a Rockwell hardness tester to test the hardness of the pressure plate, and the results should meet the requirements of 3.2.5 of this standard.

　　4.3.3 3.2.6 of this standard, the acceleration speed error should be tested under the acceleration speed of 2400N/s.

　　During inspection, the range from 12kN to FN is divided into five intervals, and the time ti corresponding to each interval △Fi is recorded with a stopwatch. The acceleration speed Vi is calculated according to formula (1):

　　........................................... (1)

　　In the formula:

　　△Fi - the interval of the selected force, kN;

　　ti——the measured time corresponding to △Fi, in s.

　　The acceleration speed of each interval shall be measured three times, and the arithmetic mean value Vi of the three measurements of each interval shall be taken, and the error of the acceleration speed of each interval shall be calculated according to the formula (2):

　　........................................... (2)

　　In the formula:

　　δi——acceleration speed error of each interval, N/s;

　　V0 - the nominal value of afterburner speed;

　　The measured error of acceleration speed at each interval shall meet the requirements of 3.2.6 of this standard.

　　4.4 Inspection of force measuring system

　　4.4.1 The relative error of indication value, relative error of indication repeatability, relative error of zero point and relative resolution of the force measuring system of the testing machine shall be inspected and calculated according to the method specified in Chapter 5 of GB/T 16825-1997 starting from 12kN. The result should meet the requirements of 3.3.1 of this standard.

　　4.4.2 For items 3.3.2, 3.3.3, 3.3.4 (except zero relative error), 3.3.5 and 3.3.7 of this standard, the inspection shall be carried out during the actual test.

　　4.4.3 The inspection of the zero point drift of the testing machine is to preheat the testing machine for a specified time, make it in a good working condition, adjust the zero point, and check the zero point drift within the specified time. Z is calculated according to formula (3):

　　................................................... (3)

　　In the formula:

　　——zero drift value, kN.

　　FN——The maximum test force of the testing machine, kN.

　　The test results should meet the requirements of 3.3.6 of this standard.

　　4.5 Inspection of the function of the testing machine

　　After adjusting the testing machine, carry out inspection according to the items required in 3.4 of this standard.

　　4.6 Inspection of safety protection device

　　4.6.1 Start the testing machine, and when the force is applied to (102%~110%) FN, observe and test 3.5.1 of this standard.

　　4.6.2 Start the testing machine, and when the test force is applied until the sample is broken, observe and test 3.5.2 of this standard.

　　4.6.3 Start the testing machine to make the piston rise, observe and test 3.5.3 of this standard.

　　4.7 Noise inspection

　　4.7.1

　　When inspecting the noise, the testing machine should be in normal working condition, and then place the microphone of the sound level meter facing the source horizontally, 1.0m away from the testing machine, and 1.5m above the ground, and measure no less than six points around the testing machine, with each The maximum value measured at the measurement point is regarded as the noise of the testing machine, and the measurement result should meet the requirements of 3.6 of this standard.

　　4.7.2 Before measuring the noise of the testing machine, the background (environment) noise should be measured first, and its value should be at least 10dB(A) lower than the noise level of the testing machine. If the difference is less than 3dB(A), the measurement result is invalid. If there is a difference of 3dB(A)~10dB(A), the test data shall be processed according to the instruction manual of the sound level meter. 4.8 Inspection of performance against bumpy transportation

　　The test machine's resistance to transport point breakage can be tested by one of the following two methods:

　　a) Fasten the packaged parts of the testing machine on the table of the collision table according to the normal transportation state, and conduct the collision test with a pulse waveform approximately half sine wave. The severity levels selected during the experiment are as follows:

　　The peak acceleration is 100m/s2±10m/s2, the pulse duration is 11ms±2ms, the pulse repetition frequency is 60 times/min~100 times/min, and the number of collisions is 1000 times±10 times.

　　b) Load the testing machine package to the rear of the truck compartment with a load capacity of not less than 4t, and carry out a transportation test of more than 100km on the intermediate road surface of the third-class road at a speed of 25km/h~40km/h.

　　After the testing machine has passed the collision test or transportation bump test, it is not adjusted and repaired, and it is fully inspected according to the requirements of this standard, and the results should meet the requirements of 3.7.

　　4.9 Inspection of assembly quality, electrical equipment, hydraulic equipment and appearance quality

　　3.8 of this standard shall be measured and inspected according to the requirements of 4.2, Chapter 6, Chapter 7 and Chapter 8 of GB/T 2611-1992.

　　5 inspection rules

　　5.1 Factory inspection

　　5.1.1 The factory inspection items are all items except 3.7 of this standard. The product can only leave the factory after obtaining the certificate of conformity.

　　5.1.2 The measured data of the main items of the factory inspection shall be recorded in the factory certificate.

　　5.2 Type inspection

　　5.2.1 Type inspection The testing machine shall be inspected according to all the technical requirements stipulated in this standard.

　　5.2.2 Type inspection should be carried out in one of the following situations:

　　a) Trial type identification of new products or old products transferred to factory;

　　b) After the product is formally produced, there are major changes in its structural design, materials, and processes that may affect product performance;

　　c) After the product has been discontinued for a long time, when the production is resumed;

　　d) When the national quality supervision and inspection agency puts forward the request for type inspection;

　　5.3 Judgment rules

　　5.3.1 For the factory inspection, the passing rate of each testing machine factory inspection item should reach 100% to be qualified.

　　5.3.2 For type inspection, when the batch size is not greater than 50 units, sample 2 units. If one unit is unqualified after the inspection, it is determined that the batch of products is unqualified; when the batch size is greater than 50 units, sample 5 units. If If there are 2 or more unqualified products after the inspection, the batch of products is determined to be unqualified.

　　6 Marking and packaging

　　6.1 Logo

　　6.1.1 The testing machine should have a nameplate, the contents of which include:

　　a) name;

　　b) model number;

　　c) date of manufacture, serial number;

　　d) The maximum test force of the testing machine;

　　e) Name of manufacturer.

　　6.1.2 For products implementing this standard, the standard number (code, sequence number, year) and name should be marked on the product or product packaging or one of the product instruction manuals.

　　6.2 Packaging

　　6.2.1 The packaging of the testing machine is waterproof, dustproof, rustproof and protective packaging.

　　6.2.2 The packaging of the testing machine should comply with the provisions of 4.4.1, 4.4.1 and 4.4.6 of JB/T6147-1992.