9 method of fault diagnosis for the electrical equipment of cnc swiss lathe machine

- Jan 17, 2018-

The fault of the electrical equipment of the cnc swiss machine can be divided into two types, one is the dominant fault, that is, the fault location has obvious appearance features, and it is easy to find. Such as relay and contactor coil overheating, smoking, burnt smell, contact melting, loose joints, abnormal voice, large vibration, inflexible movement and poor rotation. The other is a recessive fault, which is not easy to find. Such as fuse fuse. The insulating conductor is broken inside, the adjustment of the setting value of the thermal relay is improper, and the contact of the contact is not synchronized.

Therefore, to solve the problem, we should be familiar with the circuit principle of the cnc swiss machine fault equipment on the basis of preliminary sensory diagnosis. Combined with our own technology level and experience, we need to think deeply and decide a scientific and effective way to test the cause and location of the fault. There are nine common fault diagnosis methods for electrical equipment.

1, analysis method

According to the working principle, control principle and control line of the electric equipment, the fault phenomena and characteristics of the primary sensory diagnosis are combined. Make clear the system that the fault belongs to, analyze the cause of the fault and determine the range of the fault. When analyzing, first proceed from the main circuit, then analyze each control loop sequentially, then analyze the signal circuit and other auxiliary circuits, and make good use of logical reasoning when analyzing.

2, short circuit method

1. A short circuit of the electrical passage of the heart machine or a middle link with a wire. When the short circuit method is used, it is necessary to pay attention not to affect the working condition of the circuit, for example, the short circuit AC signal usually uses the capacitor, and the short connection of the wire is not used casually. In addition, short circuit connection is often used in the debugging of electrical and instrument equipment. Short circuit method is a very simple maintenance method.

For example, in the automatic circuit controlled by travel switches, limit switches and photoelectric switches, many switches are installed, and it is not easy to detect and distinguish. This method can be used for practical operation. For example, the car control system can quickly eliminate the fault by short circuit inspection.

2. Short circuit method

Note that the "test button" must not be used instead of a wire when a fault is found by a short circuit method. The short connection wire of the CNC machine is not safe to operate with the hand. At the same time, the connection terminal touched by the short connection is easily burned out by the spark. In addition, remember that when short circuit method is used to find fault, it can only connect short conductor and contact point in control circuit, and will not allow short circuit and high voltage drop in the control circuit. Otherwise, there will be short circuit or electric shock accident.

3. Open road

The open way is also called a circuit breaker. The post - stage load (mechanical or electrical load), which is connected to the fault point, is its unloaded or temporarily attached to the false load. For a multistage connection, it can be thrown open or selectively throw away the post stage. If the circuit is normal, the fault may be in the back stage, if the circuit is still not normal, then the fault is before the opening point. This method is mainly used to check the overload and low voltage fault. It is also suitable for the shift of the working point and the frequency characteristic in the electronic circuit.

For example, when judging large equipment failures, this method is often used in order to distinguish between electrical causes or mechanical causes. Such as the boiler fan can disengage coupling, respectively turning and check the fault reason.

4, cutting method

The relevant parts of the electrical connection of the NC walking machine are cut and partitioned to gradually reduce the suspicious scope. The cutting method can also be used to find the specific location of a line, or to find out the specific fault points of the fault equipment. Find the ground feeders, usually in a branch switch or facilitate the segmentation of hungry branch points for further segmentation, or according to the operation experience of inspection of key weak link: fault localization of electrical equipment inside, usually according to the structural characteristics of electrical equipment, to facilitate the segmentation in the cutting point.

5, alternative method

The substitution method is the replacement method, that is to replace the suspected electrical components or components with normal and intact electrical components or parts, so as to determine the cause of the failure and the location of the fault. The Swiss type CNC lathe electrical components such as: alternative method with plug-ins, embedded relay etc.. Electronic components, such as transistors and thyristors, are difficult to judge by general means of inspection, and they are equally applicable to alternative methods.

When adopting the substitution method, we must pay attention to that the electrical appliances used for replacement should be consistent with the specifications and models of the original electrical appliances, and the wires must be connected correctly and firmly, so as to avoid any new failures.

6. Menu method

According to the phenomena and characteristics of faults, we can list all kinds of reasons that may cause this failure, and then find and verify them one by one until we find out the real cause of the failure and the location of the fault.

The three-phase induction motor with fever smoking as an example, cited the following reasons and phenomena:

(1) partial heat of bearing

Friction between the stator and the rotor

3. Excessive or oversized voltage or oversize of three-phase voltage


Winding broken line

The stator coil, the in-phase local short circuit

The stator phase phase short circuit

The rotor is broken

9, stator winding grounding

No, no fault, does not affect the operation

7, contrastive method

Compare the related parameters or operating conditions of the fault equipment with the normal equipment. The relevant parameters of some equipment are often not found from the technical data, performance parameters in CNC lathe machine go some electrical parts in the field is difficult to judge its quality, such as a plurality of electrical equipment, can be used to contrast each other, according to the normal adjustment or replacement. This method is mostly in the "six diagnosis" of "the table test"

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