Connection debugging, inspection and acceptance of

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Connection, debugging, testing and acceptance of CNC system

connection and debugging of CNC system

5 Overload protection: automatic shutdown after sensor overload

(1) unpacking inspection of CNC system

whether it is a single purchased CNC system or a CNC system purchased with a complete machine tool, it should be carefully inspected after arrival and unpacking. The inspection includes the system body and its supporting feed speed control unit and servo motor, spindle control unit and spindle motor

(2) connection of external cables

external cable connection refers to the connection between NC device and external mdi/crt unit, strong current cabinet, machine tool operation panel, feed servo motor power line and feedback line, spindle motor power line and feedback signal line, and the connection with hand-held pulse generator. These shall comply with the provisions of the connection manual provided with the machine. Finally, ground wire connection shall be carried out

(3) the connection of the power line of the CNC system

the input cable on the original side of the power transformer of the CNC cabinet should be connected when the power switch of the CNC cabinet is cut off

(4) confirmation of setting

there are many set points with jumper short circuit on the printed circuit board in the numerical control system, which need to be set appropriately to gradually adapt to the different requirements of various types of machine tools

(5) confirmation of input power supply voltage, frequency and phase sequence

various CNC systems have DC regulated power supply inside to provide the system with the required DC voltage of + 5V, ± 5V, + 24V, etc. Therefore, before the system is powered on, check whether the load of these power supplies has a short circuit to ground. Use a multimeter to confirm

(6) confirm whether the voltage output end of the DC power supply unit is short circuited to the ground

(7) connect the power supply of the numerical control cabinet and check the output voltage

before connecting the power supply, in order to ensure safety, disconnect the motor power line first. After the power is turned on, first check whether each fan in the CNC cabinet rotates, and then confirm whether the power is turned on

(8) confirm the setting of parameters in the CNC system

(9) confirm the interface between the CNC system and the machine tool side

complete the above steps, it can be considered that the CNC system has been adjusted and has the conditions for online power on test with the machine tool. At this time, the power supply of the CNC system can be cut off, the power line of the motor can be connected, and the alarm setting can be restored

inspection and acceptance of CNC machine tools

the acceptance of CNC machine tools can be roughly divided into two categories: one is the acceptance of new CNC machine tool prototypes, which is carried out by the machine tool inspection center designated by the state; The other is the general CNC machine tool users' acceptance of their purchased CNC equipment

for the acceptance of new NC machine tool prototype, it is necessary to carry out all-round test and inspection. It needs to use various high-precision instruments to test the comprehensive performance and single performance of the mechanical, electrical, hydraulic, pneumatic and other parts of the machine tool and the whole machine, including a series of machine tool tests such as stiffness and thermal deformation, and finally get a comprehensive evaluation of the machine tool

for general users of CNC machine tools, their acceptance work is mainly based on the acceptance conditions specified on the machine tool factory inspection certificate and the actual detection means that can be provided to partially or completely measure the technical indicators on the machine tool certificate. After being qualified, it will be used as the technical index basis for future maintenance. The main work is as follows:

(1) machine tool appearance inspection

before the detailed inspection and acceptance of the CNC machine tool, the appearance of the control cabinet should also be inspected and accepted, which should include the following aspects:

1) appearance inspection visually check whether each unit in the CNC cabinet is damaged, polluted, whether the binding of connecting cables is damaged, and whether the shielding layer is peeling off under the promotion of the policy

2) the fastening inspection of components in the CNC cabinet includes the fastening inspection of screws, connectors and printed circuit boards

3) check the appearance of servo motor, especially the shell of servo motor with pulse encoder, especially the rear end

(2) machine tool performance and NC function test

now take a vertical machining center as an example to illustrate some main items

1) spindle system performance

2) feed system performance

3) automatic tool change system

4) machine tool noise the total noise during idling of the machine tool shall not exceed the standard (80dB)

5) electrical device

6) digital control device

7) safety device

8) lubrication device

9) gas and hydraulic device

10) accessory device

11) numerical control function

12) continuous no-load operation machine tool long-term continuous operation (such as 8h, 16h and 24h, etc.) is the best way to comprehensively check the reliability of the whole machine tool to automatically realize various functions

(3) geometric accuracy inspection of machine tool

the geometric accuracy of CNC machine tool is a comprehensive reflection of the key mechanical parts of the equipment and the geometric error after assembly. The following is a list of the geometric accuracy detection contents of an ordinary vertical machining center:

1) the flatness of the worktable

2) the mutual perpendicularity of the movement in each coordinate direction

3) the parallelism of the worktable when moving in the X coordinate direction

4) the parallelism of the worktable when moving in the Y coordinate direction

5) the parallelism of the T-groove side of the worktable when moving in the X coordinate direction

6) the axial movement of the spindle

7) the diameter of the spindle hole Run out

8) parallelism of the spindle axis line when the spindle box moves along the Z coordinate direction

9) verticality of the spindle rotation axis line to the worktable

10) straightness of the spindle box moving in the Z coordinate direction

(4) positioning accuracy inspection of the machine tool

it indicates the accuracy that the measured moving parts of the machine tool can achieve under the control of the numerical control device. The main inspection contents of positioning accuracy include:

1) positioning accuracy of linear motion (including X, y, Z, u, V, w axes)

2) repeated positioning accuracy of linear motion

3) return accuracy of mechanical origin of linear motion axis

4) measurement of loss of momentum of linear motion

5) positioning accuracy of rotary motion (turntable a, B, C axes)

6) repeated positioning accuracy of rotary motion

7) return accuracy of the origin of the rotary axis

8) measurement of the loss of momentum of the rotary axis motion

(5) inspection of the cutting accuracy of the machine tool

inspection of the cutting accuracy of the machine tool, and the color sand brick and the corresponding performance and color difference experimental methods are listed in the standard. In essence, it is a comprehensive assessment of the geometric accuracy and positioning accuracy of the machine tool under the conditions of cutting and processing. Domestic processing is mainly single processing. For machining centers, The main single precision includes:

1) boring precision

2) precision of milling plane of end milling cutter (X-Y plane)

3) precision of hole spacing and aperture dispersion of boring

4) linear milling precision

5) oblique milling precision

6) arc milling precision

7) concentricity of box turning boring (for horizontal machine)

8) precision of square milling with 90 ° rotation of horizontal turntable (for horizontal machine)

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