JB/T 8490-2008Floor-type boring machines and floor-type milling and boring machines - Technical requirements (English PDF)

1 Scope

This Standard specifies manufacturing and acceptance requirements for floor type boring machines and milling & boring machines.

This Standard is applicable to ordinary and numerical control floor type boring machines and milling & boring machines with a boring machine axis diameter of

130mm~260mm.

2 Normative References

The following documents contain provisions which, through reference in this text, constitute provisions of this Standard. For dated reference, subsequent amendments (excluding correction contents) or revisions of these publications do not apply.

However, all parties coming to an agreement according to this Standard are encouraged to study whether the latest edition of these documents is applicable. For undated references, the latest edition of the normative document is applicable to this national standard.

GB 5226.1-2002 Safety of Machinery - Electrical Equipment of Machines-Part 1:

General Requirements (IEC 60204-1: 2000, IDT)

GB/T 9061-2006 General Specifications for Metal-Cutting Machine Tools

GB 15760-2004 Metal-Cutting Machine Tools - General Safeguarding

Specification

GB/T 5289.3-2006 Test Conditions for Boring and Milling Machines with

Horizontal Spindle - Testing of the Accuracy – Part 3: Floor Type Machines with

Detached, Stationary Work-Holding Table (ISO 3070-3: 1997, MOD)

GB/T 16769-1997 Metal-Cutting Machine Tools - Measurement Method of Sound

Pressure Level (neq ISO/DIS 230:5.2: 1996)

JB/T 9872-1999 Metal-Cutting Machine Tools - General Specification for

Mechanical Processing Parts b) If emergency stop of the controlling mechanism is after the completion of emergency stop actuation, the function shall not automatically recover.

c) Extreme position of moving parts of each rectilinear coordinate shall have a limit device.

d) Parts, easily worn by dust, such as track of the machine tool shall have guarding devices.

e) Balancing devices of moving parts, such as headstock shall be inside the component or devices, which could prevent counter balance to drop accidentally and damage the machine tool. Guarding devices are needed for the outer part.

f) Ladders, corridor and other corresponding devices shall have strong anti-skid footrests, and shall have continuous protecting sheets and handrails along the margin.

g) If elevator is installed to lift and lower persons, it shall conform to the specifications of elevator installation and safety handling.

h) If the distance between the working platform (traverse) and the extreme lower position of the floor is less than 2.2m, the protection plate shall be painted with same-width yellow-black stripes. The strips’ width is

20mm~50mm and form an angle of 45°.

i) Machine tools using static pressure devices shall be ensured to be started up after the static pressure is established. If pressure change exceeds that specified in the provision or the electric power is off, safety shall be ensured.

7 Idle running Test of Machine Tools

7.1 Main movement structure of the machine tool shall run successively from the lowest rotational speed (step-less speed-change machine tool could run in low, medium and high speed); running time for each speed shall not be less than 2min; the running time of the highest speed shall be not less than 1h; make the main shaft bearing to reach the steady temperature; measure the temperature and temperature rise of the bearing; the temperature and temperature rise shall not exceed those specified in Table 3.

Table 3 Unit: °C

Bearing type Temperature Temperature rise

Sliding bearing 60 30

Rolling bearing 70 40

7.7.2.1 It shall be carried out according to those specified in 7.4, 7.5 and 7.7.1.1.

7.7.2.2 Automatic tool change test shall be carried out for each cutting tools in the tool changer, including cutting tools with the maximum weight in an optional method for at least two times; this test shall be carried out on each cutter spacing of the cutting tools with the maximum weight; the operation is required to be flexible and reliable.

7.7.2.3 Test shall be carried out according to function of the numerical control system.

7.7.3 Idle running tests shall be continuously carried out for the machine tool with the numerical control command and the continuous running time shall not be less than 36h. Off-time between automatic cycles shall not exceed 1 min; the entire operation process shall be free from malfunction.

In the test, automatic cycle shall include all functions of the machine tool and following content:

a) Main shaft includes forward and reverse rotation with low, medium and high rotary speed; the time is generally not less than 10% of the time for each loop program.

b) Moving parts of each coordinate shall include in low, medium and high feed speed, and fast forward running in the forward and backward direction; the running shall be within the range of the whole stroke; an arbitrary point may be selected for positioning. Operation time with high speed of feed and rapid operation is generally not less than 10% of the time for each loop program.

c) Cutting tool on the cutter position in the tool changer shall not be less than two times of automatic exchange;

d) Linkage of each linking coordinate axis.

8 Load Tests of Machine Tools

The following load tests shall be carried out for machine tools:

a) Test for maximum torque of the main transmission;

b) Test for the maximum resistance to cutting;

c) Test of maximum efficiency of the main transmission (random inspection).

9 Accuracy Inspection of Machine Tools

9.1 Accuracy inspection for machine tools shall be carried out according to GB/T

5289.3-2006; in which, the inspection for G13 and G18 shall be carried out when main shaft of the machine tool reaches the medium speed and stable temperature.