Some standard content:
Coal Industry Standard of the People's Republic of China
Double-column parallel hydraulic top-cutting support
1 Subject content and scope of application
MT324-93
This standard specifies the product classification, technical requirements, test methods, inspection rules, marking, packaging, transportation and storage of double-column parallel hydraulic top-cutting support.
This standard applies to double-column parallel hydraulic top-cutting support for coal mine recovery working face. 2 Reference standards
GB 197
Tolerances and fits of ordinary threads (diameter 1355mm)GB1184
Tolerances of form and positionSpecified tolerances and fits of dimensions without tolerancesLimit deviations of dimensions without tolerancesGB 1804
GB 2649
Methods of sampling for mechanical properties test of welded jointsMethods of impact test of welded joints
GB2650
Methods of tensile test of welded joints
GB 2651
GB 2652
GB 2653
Methods of tensile test of welded and deposited metal
Methods of bending and flattening test of welded joints
GB 3452. 1
GB 3452. 3
GB 11352
Dimension series and tolerance
O-rings for hydraulic and pneumatic applications
Groove dimensions and design calculation criteria for O-rings for hydraulic and pneumatic applications - Cast carbon steel parts for general engineering
GB/T13306 plate
JB3338 Technical conditions for cylindrical helical compression springs for hydraulic parts JB/T5943 General technical conditions for welding parts for engineering machinery MT76 Emulsified oil for hydraulic supports
Cylinder and column diameter series for columns and roofs of hydraulic supports for mining MT 94
MT313 Technical conditions for hydraulic support columns
Technical conditions for hydraulic support jacks
Type test specifications for hydraulic support hose assemblies and intermediate joint componentsMT112
Mine single hydraulic support
Mine hydraulic support valve type test specificationsMine hydraulic support valve pressure flow seriesMT177
Mine hydraulic support valve connection type and size seriesMT 179
3 Terms
General technical conditions for mine hydraulic support valves3.1 Double-column parallel hydraulic top-cutting support (hereinafter referred to as "top-cutting support"): It consists of two parallel columns, an integral seat box, a top cover and a push jack. It uses the hydraulic principle to support the top plate, push the conveyor, and move the top-cutting support (see Appendix C for a schematic diagram). Approved by the Ministry of Energy of the People's Republic of China on February 25, 1993 and implemented on October 1, 1993
MT 324--93
3.2 Column: It is composed of a cylinder body, a piston including a mechanical extension section and connecting parts and components mounted thereon. 3.3 Jack: It is composed of a cylinder body, a piston rod and connecting parts and components mounted thereon. 3.4 Seat box: An integral seat box welded from steel plates, used to fix the column and connect the jack. Top cover: A rigid component that connects the end of the column and piston to the top plate. 3.5
4 Product classification
4.1 According to the structural characteristics and application scope of the product, it is divided into: a. Cut-topping pillar composed of a single telescopic column; b. Cut-topping pillar composed of double telescopic columns; and a. Cut-topping pillar with anti-falling, anti-slip and net-laying mechanism. C
4.2 Model compilation method:
4.2.1 Type and characteristic codes are represented by capital letters of Chinese Pinyin. Q represents truncated pillar. In the first characteristic code, S represents double pillar. In the second characteristic code, when the pillar is double telescopic, it is represented by S, and when the pillar is single telescopic, no code is marked. In the supplementary characteristic code, the anti-falling and anti-slip type truncated pillar is marked with F; the net-laying type truncated pillar is marked with P; if the same product is both an anti-slip type truncated pillar and has the function of laying nets, the supplementary characteristic code is separated by a slash, with the anti-falling and anti-slip type code marked on the upper part and the net-laying function code marked on the lower part. That is, it is marked as follows: "F/P"; the modification number is represented by capital Chinese Pinyin (A), (B), (C), and. in brackets to distinguish different products with the same type, main parameters, and characteristic codes.
4.2.2Model example
Modification number
Supplementary characteristic code
Rated working resistance of truncated support, kN
Maximum height of truncated support, dm
Second characteristic code
First characteristic code
Type code
QS25/2000F truncated support, indicating a single telescopic double-column anti-falling and anti-slip truncated support with a working resistance of 2000kN and a maximum support height of 2.5m.
4.3Basic parameters
4.3.1The cylinder diameter and column diameter of the column and jack shall comply with the provisions of MT94. 4.3.2The maximum height of the truncated support shall comply with the provisions of Table 1. Table 1 Maximum height of truncated support
4.3.3The rated working resistance of the truncated support shall comply with the provisions of Table 2. 2500
Table 2 Rated working resistance of truncated support
4.3.4 The piston rod stroke of F-jack shall comply with the provisions of Table 3. 320
5 Technical requirements
5.1 General technical requirements
MT 324—93
Table 3 Piston rod stroke of dry jack
5.1.1 The product shall comply with the requirements of this standard and be manufactured in accordance with the design drawings and technical documents approved by the prescribed procedures. 1300
5.1.2 Raw materials, standard parts, purchased parts and outsourced parts shall be accepted by the quality inspection department of the truncated support manufacturer before they can be used. 5.1.3 The basic parameters of the truncated support shall comply with the provisions of Article 4.3. The maximum height limit deviation is 20mm. The width is determined by the on-site use conditions and the limit deviation is 10mm.
5.1.4 The ordinary thread fit shall comply with the 6th grade accuracy of GB197. 5.1.5 Steel castings shall comply with the provisions of GB11352. 5.1.6 Forgings shall not have interlayers, cracks, folds, stutters and other defects. Local defects caused by reasons such as removing scales are allowed on non-machined surfaces. Under the condition of ensuring the size deviation of forgings, inclined scraping or trimming of defects is allowed. 5.1.7 Welded parts shall comply with the provisions of JB/T5943. The quality of welds shall meet the following requirements. a. Welds that bear liquid pressure must be subjected to pressure resistance tests. The welds of the column cylinder body shall be tested at 2 times its rated working pressure, stabilized for 5 minutes, and no leakage shall be allowed.
b. Metal mechanical properties of pressure-bearing welds:
Tensile strength ab≥600MPa
Elongation 5≥20%
5.1.8 High-pressure hose assemblies and intermediate joints shall comply with the provisions of MT98. 5.1.9 Hydraulic cylindrical helical springs shall comply with the provisions of JB3338. 5.1.10 For the limit deviation of the dimensions not indicated in the drawings, those with inclusive relationship shall be manufactured according to the IT14 level precision of GB1804, and those without inclusive relationship shall comply with the IT15 level of the above standard.
5.1.11 The geometric tolerances of the dimensions not indicated in the drawings shall comply with the provisions of tolerance grade C in GB1184. 5.1.12 The valves for the top-cut pillars shall comply with the relevant provisions of MT119 and MT177~~179. 5.1.13 The dimensions and matching grooves of the O-rings shall comply with the provisions of GB3452.1 and GB3452.3. 5.2 Technical requirements for assembly
5.2.1 Before assembly, the burrs, chips, oil stains, etc. on all surfaces of all parts shall be cleaned and assembled only after they are qualified. 5.2.2 During assembly, all connecting threads and machined surfaces of parts indicated in the drawings shall be coated with thread anti-rust grease to prevent rust. 5.2.3 During assembly, the mating surfaces of parts shall not be damaged. Individual minor scratches may be repaired after approval by the technical inspection department, but they shall not affect the performance and reduce the service life.
5.2.4 All exposed oil ports shall be sealed with plastic plugs. 5.2.5 All parts shall be installed correctly and connected firmly. 5.3 Appearance Technical Requirements
5.3.1 The non-machined surface of the casting shall be flat, without flash, oxide scale, gate, casting sand, etc. 5.3.2 The weld of the welded parts shall be dense, flat, and free of welding slag. Cracks, slag inclusions, etc. are not allowed. 5.3.3 The appearance quality of the surface coating shall comply with the provisions of B6 in Appendix B. 5.3.4 The exposed surface of the product, except those that have been surface treated, shall be coated with anti-rust primer and then with topcoat. The paint layer shall adhere firmly. The paint layer on the outer surface should be bright, uniform, without cracks, peeling or trimming. 5.3.5 The color of the paint layer on the outer surface should be eye-catching, comfortable and easy to observe underground. 5.3.6 The various signs of the product should be installed correctly, firmly and reliably. 321
5.4 Technical requirements for electroplating
5.4.1 All galvanized parts should be passivated. 5.4.2 The technical requirements for coating quality shall be implemented in accordance with Appendix B. 5.5 Cleanliness requirements
MT324—93
Before assembling the product, burrs, flash and iron filings should be removed. Hydraulic components should be strictly cleaned, and the cleanliness of the product cavity should meet the requirements. The values of each single telescopic column shall not exceed those in Table 4, and the values of each double telescopic column shall not exceed those in Table 5; the values of each jack shall not exceed those in Table 6; and the values of each valve shall not exceed those in Table 7.
Table 4 Mass of impurities in single telescopic column
Column cylinder diameter, mm
≥200
Column cylinder diameter, mm
≥200
Mass of impurities in dry hall items
Table 5 Mass of impurities in double telescopic column
Table 6 Mass of impurities in jack
Table 7 Mass of impurities in valves
Safety valve, one-way valve, control valve and other valve parts5.6 Performance technical requirements
5.6.1 Operation performance test requirements
Mass of impurities, mg
Mass of impurities, mg
The top-cutting column should be easy to operate, and its telescopic length and telescopic procedure should comply with the requirements of the drawings, and there should be no stagnation, creeping, external leakage, etc. The height and width of the top-cutting column and the stroke of the dry jack should comply with the provisions of Articles 5.1.3 and 4.3.4. 5.6.2 Minimum starting pressure requirements
Under no-load and no-back pressure conditions, the minimum starting pressure of the piston chamber of the column and the dry jack shall not be greater than 3.5MPa, and the minimum starting pressure of the piston rod chamber shall not be greater than 7.5MPa.
5.6.3 Initial support force determination
The extension and retraction speed of the column and the dry jack shall meet the design requirements. The initial support force of the top-cut pillar shall not be less than 95% of the design value. 5.6.4 Flexibility and reliability determination of the push mechanism The push mechanism should be adjusted flexibly and in place. When the jack is at 110% of the rated fluid supply pressure, the connecting parts of the dry jack shall not be deformed or damaged.
5.6.5 Anti-fall and anti-slip performance
For the top-cut pillar with anti-fall and anti-slip mechanism, the anti-fall and anti-slip mechanism shall be stable and reliable under the premise of not exceeding the design angle, and can meet the normal operation of the product.
5.6.6 Sealing performance requirements
MT 324-93
When the column, lower jack piston chamber and piston rod chamber are respectively in low pressure and high pressure conditions, at the same temperature, the pressure shall not drop within 5 minutes and there shall be no leakage within 4 hours.
5.6.7 Durability performance requirements
The top cover is in the A1 condition in Appendix A. The seat box is subjected to the A4, A5 and A6 stress conditions in Appendix A respectively, and the column is loaded with a rated working pressure cycle.
The effective stroke of the piston shall not be less than 150m, and the number of cyclic loading shall not be less than 3000 times. The number of cyclic loading for each loading method shall be 1000 times. The relevant tests in Article 5.6.6 shall be repeated every 50m, and the requirements shall be met; b. Add a pad under the top cylinder of the dry hall to make the jack and the column seat box in the extreme position on the vertical plane. The number of push, pull and cycle times with the rated liquid supply pressure shall not be less than 3000 times;
After the durability test, the top pillar seat box and the top cover shall not produce cracks or deformation, and the cumulative residual deformation of the connecting pins, ears and other connecting parts shall not be greater than 0.5% of their respective load-bearing lengths. 5.6.8 Strength requirements
After the strength test, each component and limit mechanism shall not produce permanent deformation and damage, and the stress at the dangerous section shall not exceed the yield limit of the material. 5.6.9 Cylinder explosion requirements
The cylinder body is closed at both ends and pressurized until it is destroyed. Its destruction form shall not be broken into pieces. 6 Test method
6.1 Test conditions
6.1.1 The working medium is an emulsion prepared by emulsified oil and neutral soft water in a weight ratio of 5:95 as specified in MT76. 6.1.2 The working medium temperature is 10-50°C, and the working medium is filtered by a filter with a precision of 0.125mm (120 mesh/inch), and a magnetic filtering device is provided.
6.1.3 Measurement accuracy
6.1.3.1 Measurement level
According to the accuracy requirements, the C level is adopted for the top-cut pillar. 6.1.3.2 Error
Any measuring system that has been calibrated or compared according to relevant standards, if its system error does not exceed the limits listed in Table 8, can be used for tests of equivalent measurement levels.
Table 8 Permissible system error of the measurement system
Measurement level
Pressure equal to or exceeding 2X105Pa
% (gauge pressure)
Note: The fractional limit range given belongs to the measured value, not the test maximum value or the maximum reading value of the measurement system. 6.1.3.3 The accuracy of the direct-reading pressure gauge is 1.5 level; the pressure gauge range should be 140% to 200% of the test pressure. 6.2 Assembly quality inspection
Inspect according to 5.2 using the monthly test method.
6.3 Appearance quality inspection
Inspect according to 5.3 using the stomach test method.
6.4 Weld quality inspection
6.4.1 Inspect all welds using the daily test method, and their external defects shall not exceed the provisions of JB/T5943. 6.4.2 According to the provisions of GB2649~2653, the welding procedure qualification test shall be carried out, and the test results shall comply with the provisions of Article 5.1.7 of this standard. 323
MT 324-—93
6.4.3 According to the requirements of Article 5.1.7 of this standard, the pressure-bearing weld shall be subjected to a pressure test. When the pressure increases to the specified value, the pressure shall be maintained for 5 minutes, and then reduced to the rated working pressure. The weld shall be tapped with a hammer for inspection. No leakage shall be found. 6.5 Coating quality inspection
6.5.1 Appearance quality inspection shall be carried out under natural scattered light or white transmitted light without reflected light. The illumination shall not be less than 3001x (i.e., the illumination of the inspected surface at 500mm under a 40W fluorescent lamp), 300mm away from the inspected surface, and visual inspection shall be carried out in the direction of 45 degrees, which shall comply with the provisions of B6 in Appendix B.
6.5.2 Porosity test Dip the filter paper in chemical reagent, stick the filter paper on the surface of the tested coating, then remove the filter paper and calculate the number of pores per unit area. It should comply with the provisions of B5 in Appendix B. 6.6 Cleanliness test
Wash the tested parts with oil or emulsion twice, filter the cleaning liquid with a filter screen with an accuracy of 0.125mm, then dry the residue on the screen and weigh the mass, which should comply with the provisions of Article 5.5. 6.7 The test method of the top-cut pillar is shown in Table 9
6.8 In addition to meeting the relevant provisions of Article 6.7, the pillars, dry jacks and valves in the top-cut pillars should also meet the following technical requirements: a.
The pillars should comply with the provisions of MT313.
The jacks should comply with the provisions of MT97.
The valve type should comply with the requirements of MT119 and MT177~179. For safety valves with a flow rate of less than 3L/min, the test method for the whole frame of the topping support in Table 9 of MT112 shall be followed.
Test items
6.7.1 Operability
Performance test
6.7.2 Minimum starting pressure
Determination of initial support force
6.7.1 Pusher
Test method
The topping support is in a no-load condition. Repeat the full stroke of the column lifting and the extension and retraction of the jack for 3 times. Measure the height of the topping support and the stroke of the piston rod of the dry jack
The column and the jack are in a no-load condition. Gradually increase the pressure and measure the minimum starting pressure of the column, jack piston cavity and piston rod cavity respectively.
(All are carried out without back pressure)
Under the rated fluid supply pressure and flow, operate the lifting column for no less than 3 times in the working surface operation sequence to measure the initial support force of the pillar
Connect the push jack to the middle groove of the conveyor according to the design requirements, measure the activity of the free end of the dry jack, make the structure flexible, and when the column and the dry jack are in the limit position, push the slide with 110% of the rated supply pressure. Pull the frame (column), repeat the operation 3 times. Determination of reliability. 6.7.5 Determination of anti-falling and anti-slip performance. 6.7.6 Sealing performance test. Place the top-cutting support on a tiltable test bench, extend it to the maximum height, gradually increase it from 10° to the design angle, and push the top-cutting support through the full stroke 3 times under the maximum design angle. Performance requirements. 1) The column piston rod cavity and the dry jack piston cavity and piston rod cavity are stabilized at 1 MPa and 110% of the rated pump pressure respectively. 5.6.6
2) The column is raised to 2/3 of the stroke and axial loading is applied. The piston chamber is kept at 1MPa and 110% of the rated working pressure for 5min respectively
3) With dry jack, each column chamber is kept at the above pressure for 4h. No.
Test Item
Durability
Performance Test
Strength Test
MT 324-93
Continued Table 9
Test Method
1) The column is extended to 2/3 of the stroke. The top cover and the seat box are subjected to continuous cyclic loading at the rated working load under the stress conditions of A1 and A4, AI and A5, A1 and A6 in Appendix A, respectively. The loading speed is not more than 20-25mm/min2) A block is added under the cylinder of the dry jack to make the jack and the column seat box in the extreme position on the vertical plane. The column is tightened and the piston chamber and piston rod chamber of the lower jack are subjected to full stroke cyclic loading respectively with the rated fluid supply pressure. The relevant tests of 1) and 2) in 6.7.6 are repeated every 500 times
3). After the above three tests are qualified, repeat the test of 6.7.61) The column is extended to the maximum height, and the piston chamber is pressurized to 1/1 of the rated working pressure. 25%, for 5 min2) The column is extended to the maximum height, and the axial outward load is 150% of the rated working load, for 5 min3) The column is extended to the maximum height, and the axial outward load is 110% of the rated working load under various loading methods in Appendix A, for 5 min
4) The column is extended to the maximum height, and the axial preload of the rated initial support load is applied, and the column head is impacted twice with an energy of 15 kN·m 5) After the above test is completed, repeat the test of 6.7.1 6.7.9 Cylinder explosion The two ends of the cylinder body are closed, and the pressure is gradually increased by a pressure pump until it is destroyed, and the destruction pressure is recorded.
Performance requirements
Note; (D) The cylinder explosion test allows the method of reducing the cylinder wall thickness to reduce the destruction pressure, but the minimum destruction pressure shall not be less than 250% of the rated working pressure.
② For trial production of products or changes in the design material of the column cylinder, the explosion test should be carried out. 7 Inspection rules
7.1 Inspection of the topped pillar is divided into factory inspection and type inspection. The inspection items shall be carried out in accordance with the contents specified in Table 10. Table 10
Inspection items
Appearance quality inspection
Weld pressure bearing capacity inspection
Assembly quality inspection
Coating quality inspection
Cleanliness requirements
Operational performance test
Minimum starting pressure test
Determination of initial support force
Determination of flexibility and reliability of the sliding mechanism
Determination of anti-falling and anti-slip performance
Sealing performance test
Inspection classification
MT324-93
Continued Table 10
Inspection Items
Durability Test
Strength Test
Cylinder Burst Test
Safety Valve Performance Test
Hydraulic Control Check Valve Performance Test
Directional Valve Performance Test
Stop Valve Performance Test
Circuit Breaker Valve Performance Test
High-Pressure Hose and Joint Performance Test
Note: "√" in the middle indicates that the item is fully inspected; "△\" indicates that the item is sampled; "×" indicates that the item is not inspected. 7.2 Factory Inspection
Inspection Classification
7.2.1 Each product shall be inspected by the quality management department of the manufacturer according to the design drawings and the provisions of this standard. After passing the inspection, it can be shipped with the product certificate attached.
7.2.2 The samples for the random inspection items shall be 2% of the batch each time, but shall not be less than 3 sets. 7.2.3 If one of the random inspection items fails, double sampling shall be conducted. If one item still fails in the re-inspection, the batch of products shall fail. 7.3 Type inspection
Type inspection shall be conducted for new product identification and finalization or old product transfer and trial production in any of the following situations: when the product design, process and materials are changed and the product performance is affected; when the product is produced again after being discontinued for more than one year;
When the user has major objections to the product quality; when the national quality supervision department makes a request. 7.3.2
The type inspection prototype is one.
All type inspections specified in this standard shall be conducted by the relevant quality inspection centers authorized by the state. Items that fail the type inspection are allowed to be retested after repair. If they still fail, the item shall be doubled for sampling. If they fail again, the type inspection shall be failed. 7.3.4
8 Marking, packaging, transportation, storage
Each product should have a nameplate, which should include the following: 8.1
Product name;
Product model:
Year, month, day of production:
Manufacturer) name;
Weight.
MT324—93
8.2The size and technical requirements of the nameplate should comply with the provisions of GB/T13306. Products that have won quality awards should have a quality award mark on their nameplates. 8.3After the top-cut pillar passes the inspection, its column and jack should be retracted to the shortest position. Its dry jack (including the valves and pipe fittings on it) should be packaged separately from the seat box and tied firmly with wire. Other parts should be packaged in wooden boxes. 8.4 Technical documents accompanying the product:
Packing list;
Product certificate for each unit;
Product maintenance manual - one copy;
Product wearing parts and spare parts list - one copy.
8.5 Spare parts and wearing parts of the top-cutting support should be shipped in special packaging boxes to prevent loss and mixing. 8.6 The lifting hole should be used for lifting the product. It is strictly forbidden to directly lift the ceiling cover. 8.7 When the product leaves the factory, its columns and jacks should be filled with emulsified antifreeze according to the transportation process and the lowest temperature in the use area. Generally, when the temperature is below 25°C, MFD-40 emulsified antifreeze should be injected; when it is between -25 and +5°C, MFD-25 antifreeze should be injected; when it is between -5 and +5°C, MFI-15 emulsified antifreeze should be injected.
8.8 The topped pillars should be stored in a dry warehouse or under cover, and the ambient temperature should not be lower than 0°C. 8.9 If the topped pillars are stored for more than three months, check whether the emulsion in the inner cavity of the pillars, jacks, and valves has deteriorated. If so, they should be replaced. 327
Loading method
Pre-cover edge
Edge concentration
Inside the top cover
Side eccentricity
Outside the top cover
Side eccentricity
MT324—93
Appendix A
Position and size of pads for various loading methods (supplement)
Position of pads
b=60mmbzxz.net
Pad size
t=Column head diameter
L≥500 mm
6=60mm
t21/4 column head diameter, but not less than
L≥500mm
b=60mm
t2=1/4 column head diameter, but not less than
L≥500 mm
Thickness of cushion block
8--15mm
Material: Q235-A
Thickness of cushion block
Material: Q235-A
Thickness of cushion block
Material: Q235-A
Loading mode
Base set
Central loading
Base eccentric
Central loading
Base eccentric
Central loading
Block position
MT 324--93
Continued table A1
b=60 mm
t3=10mm
L≥base width
b=60 mm
t,=60 mm
L≥base width
660 mm
ta = 60 mm
L≥base width
Pad size
Pad thickness
8=40mm
Material Q235-A
Pad thickness
9=40mm
Material: Q235-A
Pad thickness
8=40mm
Material: Q235-A
B1 Basic requirements
MT 324—93
Appendix B
Technical requirements for electroplating layer of cut-top pillar parts (supplement)
Before electroplating, the material, size, accuracy and surface defects of the plated parts should be inspected. If they do not meet the requirements, the electroplating process shall not be carried out. B2 Plating selection
The column piston rod should adopt composite plating
Copper-tin alloy and hard chrome;
Copper-tin alloy and milky chrome;
Milk chrome and hard chrome.
Other parts are generally electroplated with zinc plating, and other plating types that can effectively protect the surface of the parts can also be used. B2.2
Thickness of coating
B3.1Thickness of various coatings using composite coating: a.
Copper-tin alloy 20~30μm, hard chrome 30~~40μm; copper-tin alloy 20~30μm, opalescent chrome 30~50μm; b.
Oopalescent chrome 20～~30μm, hard chrome 30～40μm. c.
B3.2Thickness of coating using zinc plating or other plating: a.
7~15 μm;
15~25μm;
25~~35 μm.
B3.3When there are special requirements for coating thickness, it shall be implemented in accordance with the provisions of the drawing documents. B4 Hardness of coating
Hard chrome (composite) shall not be less than HV800;
Opale chrome (composite) shall not be less than HV500;
Single chrome layer shall not be less than HV700.
B5 Combination requirements
Porosity of coating shall not be greater than 15 points/dm2 and diameter shall not be greater than 0.2mm. B5.1
B5.2 The method for determining the porosity of coating is to dip filter paper in chemical reagent, then stick the filter paper to the surface of the coating to be tested, then remove the filter paper and calculate the number of holes per unit area.
B5.3 The coating shall not have peeling, shedding or blistering. B6 Appearance quality requirements of coating
B6.1 The coating crystallization should be fine and uniform, and the following defects are not allowed: a.
Surface roughness, particles, burning, cracks, blistering, shedding; dendritic crystallization;
Partial absence of coating or exposure of the intermediate layer;
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