High voltage connectors are widely used in ac and dc eight-axis electric locomotives,It is mainly composed of porcelain bottle, cover plate assembly, sheep horn, bellows, jacking rod, crosshead assembly, locking device and so on.As shown in Figure 1,Its main function is to achieve the eight-axis electric locomotive A section and B section roof high voltage circuit reliable connection.And can achieve control in the driver’s cab,Avoid dangerous roof work,In mass production, there are occasions when two butt high voltage connectors cannot be rejoined after separation.
2. Analysis of docking failure
The frequency of docking failure is low,But once that happens, it’s hard to rule it out,Only remove and replace the horn of the high voltage connector,To revalidate,The high voltage connector butt failure is directly manifested as:When the two high voltage connectors are separated, the lock tongue on the horn of the ram is not opened,the ring on the horn of the sheep cannot be inserted into the lock when it is closed next time, resulting in failure,At present,The method to solve the fault is:Remove the ram horn of the high voltage connector,Check each part against the drawing to find out the problem parts.Replace and reassemble.After several disassembling and summarizing, it is found that the deformed part is the clamp in the horn,But because the clamp and other parts in the horn constitute a complex four-axis structure.Quantitative and qualitative analysis cannot be carried out on site. The locking tongue, clamp and ring in the horn are shown in FIG. 2.
3. Using CATIA 3d model to analyze docking faults
CATIA 3d modeling can perfectly simulate each part in a computer，Assemble parts as based on drawing，Realize the quantitative control of motion displacement of each part，And synchronize the motion track of the associated parts，Therefore, CATIA 3d modeling analysis is more advantageous and efficient than traditional field analysis.
The following 3d modeling is used to analyze the influence of clamp deformation on high-voltage connector by CAT worker A，Three-dimensional modeling, assembly and constraint of CAT worker A were carried out for the clamps and related parts of sheep horn, as shown in figure 3 (the spring was simulated by the constraint system of CAT worker A).
As can be seen from figure 3, the tension spring and the cover plate are connected by an axis, the clamp and the tension spring are connected by an axis, the clamp and the locking tongue are connected by an axis, and the cover plate and the locking tongue are connected by an axis, forming a complex four-axis structure.As long as any axis in the four-axis structure in figure 3 is rotated (realized by Angle constraint), other axes are rotated at the same time, and various states of the locking tongue are quantitatively analyzed in this linkage mode.FIG. 4 shows that the diameter of the ring (12mm) is greater than the width of the locking tongue from the cover plate at rest (10.23mm).When the high voltage connector is separated, the ring will pull down the locking tongue to break the balance and the locking tongue will be opened. Figure 6 shows that the opening of the locking tongue is maintained by an upward sloping force. The above analysis proves that the high voltage connector design is correct.
Figure 7 shows when the width of the latch and cover plate is equal to the diameter of the ring (12 mm),The position of clamp and spring connecting shaft moves up 4.83mm compared with the normal position,At this point, the clamp and spring connecting shaft clamp and latch tongue connecting shaft cover plate and latch tongue connecting shaft are in the same line,reach a balance,This is the critical point where the docking failure occurs,therefore,When the clamp is deformed, the coupling shaft of the clamp and spring moves upward more than 4.83mm,There will be a docking failure. The limit simulation of docking failure is shown in figure 7.
Through three-dimensional simulation of CAT worker A, it is concluded that joint failure will occur if the bending deformation of the clamp is greater than 4.83mm,The clamps in the horn of the high voltage connector are made of stainless steel with low hardness and easy deformation.
Field measurement shows that the bending deformation of the faulty clamps is greater than 4.83mm, which well verifies the conclusion drawn by CATIA three-dimensional analysis,In the subsequent production, the material of the clamp is replaced with ordinary Q235A steel plate,The surface is chrome plated, which not only enhances the strength of the clamp (avoid deformation), but also reduces the production cost. Therefore, the new clamp effectively reduces the occurrence of high voltage connector joint failure.