Technical specification for automobile low voltage harness

Automobile circuit is an important part of automobile. The functions and signals in automobile circuit are transmitted through automobile Wire harness Bridge connected. automobile Wire harness Fixed to the whole body,Wire harness The damage directly affects the performance of automobile circuit. Article 4.11 ~ 4.15 of the technical conditions for automobile low voltage harness (QC / t29106-2004) stipulates that the automobile harness shall have the properties of high and low temperature resistance, temperature resistance, wet cycle resistance, vibration resistance, smoke resistance, industrial solvent resistance, etc. Therefore, the external protection of the harness plays a vital role. Reasonable external protection materials and packaging methods can not only ensure the harness quality, but also reduce the cost and improve the economic benefit.

automobile Wire harness Corrugated pipe is made of polypropylene (nylon 6), polyethylene (polyethylene), polypropylene (polypropylene) and other materials by heating and extrusion. It is widely used in mechanical equipment, automobile and other industries to protect wire harness. The working temperature of bellows is generally - 40 ℃ ~ + 130 ℃, and can reach + 140 ℃ in a short time. Both inside and outside are waveform, which has the characteristics of good flexibility, good torsion resistance, good oil resistance and so on.

To protect the car Wire harness Japanese cars usually add protective sleeves at both ends of the cut bellows, while German cars usually require the cutting position to be in the center of the wave crest.

At present, some small and medium-sized enterprises use semi-automatic methods to cut German cars Wire harness Bellows, that is, determine the length of bellows with a fixed ruler, preliminarily determine the axial position of bellows with a special die, and manually assist the axial positioning and clamping of bellows to ensure that the position is basically unchanged. This method requires a long period of initial adjustment and a large amount of waste. Due to the need to manually move the bellows, the labor intensity of workers is high, the work efficiency is low, the scrap rate is high, and the production safety can not be guaranteed. A few enterprises use the full-automatic automobile harness bellows cutting equipment produced in Germany, which has high cutting efficiency and low scrap rate, but the equipment price is high. Therefore, there is an urgent need to develop a domestic automatic automobile harness bellows cutting equipment to achieve high cutting efficiency, low scrap rate, automatic production, reduce material waste, reduce enterprise labor cost and improve enterprise efficiency and efficiency.

1. Car Wire harness Development of bellows automatic processing system.

1.1 development technology of automatic processing system for automobile harness bellows.

automobile Wire harness The full-automatic cutting device of bellows includes feeding device, automatic feeding device, automatic cutting device and automatic discharge device. Automatic cutting device is the core equipment.

The main technical contents of the automatic cutting device include the theoretical research on the correct positioning technology of the cutting position of the bellows, the automatic conveying of the bellows, the correct positioning of the cutting position of the bellows, the mechanical structure design, algorithm implementation and automatic control of the bellows cutting and automatic counting of the bellows processing.

(1) The theoretical research of bellows precise conveying technology includes the selection of theoretical research methods, the theoretical analysis of correct positioning technology and the realization of correct positioning algorithm.

(2) The automatic bellows conveying device includes bellows conveying device, positioning device, clamping device, etc.

(3) The correct positioning technology of bellows cutting position includes the research of bellows position dynamic control technology, the selection of bellows position dynamic control components, and the design of bellows position dynamic control system.

1.2 automobile Wire harness Development of bellows automatic loading device.

automobile Wire harness Bellows loading device: support seats are set at the four corners of the lower part of the bottom plate, and its height and level can be adjusted at any time. A hollow cuboid is connected in the middle of the bottom plate, and two motors are installed on each side of the cuboid. The motor is connected with the worm gear reducer, and the output of the reducer is connected with the rotating cylinder. The factory bundled automobile harness bellows are sleeved on the rotating cylinder, and then fixed axially. Among them, worm gear reducer and matching AC motor are selected as reducer.

1.3 automobile Wire harness Development of bellows automatic feeding device.

automobile Wire harness Corrugated pipe feeding device: adjust the moving direction of the evenly loosened corrugated pipe through the grooved wheel mechanism, so that it can be pulled horizontally by the automatic cutting device without jamming. A photoelectric switch is arranged above and below the column of the feeding device to detect the input and output speed of the conveying bellows of the feeding device to ensure reasonable transportation speed. Its basic structure is that the middle part of the square underframe is provided with a column, the column is provided with a beam, the bottom of the column and the beam are provided with guide wheels, and the column is evenly provided with threaded holes for installing photoelectric switches for equidistant installation of several proximity switches. The moving speed of the bellows is detected according to the linear speed limit area of the pipeline, so that the conveying speed of the pipeline is coordinated with the speed of the pipeline pulled by the bellows cutter, Avoid pipeline damage or fracture, too fast pipeline conveying speed and too slow traction speed of bellows cutter, resulting in pipeline accumulation.

Action sequence: bind the bellows to the rotating cylinder → lead the bellows to the sheave mechanism → bypass the sheave mechanism to the automatic bellows cutting device.

1.4 automobile Wire harness Development of bellows automatic cutting device.

1.4.1 action sequence.

Corrugated pipe clamping → corrugated pipe conveying → corrugated pipe moves to the tool cutting position along with the conveying device → positioning adjustment of mechanical positioning device → position sensor detects whether the tool cutting position is the peak value → tool cutting alignment peak value, tool cutting alignment peak value, tool cutting alignment peak value

1.4.2 bellows clamping and traction mechanism.

Bellows introduction: the stepping motor is used to drive the toothed belt to pull the bellows. For bellows with different diameters, the method of adjusting the spacing between toothed pulleys is adopted. After the bellows is introduced, it runs at a certain speed and stops after it moves to the specified position.

1.4.3 positioning and cutting structure.

The positioning sensor detects the peak and valley position of the bellows. If the positioning sensor does not center the wave crest position of the bellows, the positioning sensor and tool cutting device will follow up slightly (within one cycle). After centering with the wave crest and valley position of the bellows, the positioning sensor and tool position will not be fixed. The basic implementation method is: the relative position of the positioning sensor and the tool cutting device remains unchanged. When the length or diameter of the cutting bellows changes, the correctness of the positioning sensor and the tool cutting device is automatically adjusted through the control program. If the position is incorrect, the feed motor moves to adjust the cutting position; First meet the requirements of cutting to peak value, and then meet the requirements of cutting length. For the accurate positioning of bellows, the combination of mechanical structure positioning and detection element detection is adopted. For the on-line identification of bellows peak position, the combination of detection before tracking, Kalman algorithm and development program is used to solve the reliability of feature detection. For the closed-loop control algorithm of bellows peak position, photoelectric encoder (preliminary positioning and automatic positioning) is used as automatic positioning (automatic positioning).

1.5 automobile Wire harness Development of bellows automatic discharge device.

The automatic discharge device of bellows comprises a conveying device, a gripping device and a packing platform. The conveying device includes a conveying frame and a conveying mechanism, the gripping device includes a gripping mechanism and a mechanical arm, and the packing platform includes a packing foundation and a packing support. When in use, the cut bellows slides to the middle of the rubber diaphragm of the conveyor belt through the longitudinal roller, and the bellows is transported below the gripping mechanism through the conveyor belt. The lifting motor in the mechanical arm drives the lead screw to rotate, the lifting mechanism runs downward, the gripping driving motor runs, the gripping driving motor rotates through the transmission device, and the lifting mechanism runs upward, Rotate the rotating base above the packing tray and place the special bundle box on the packing bracket. It does not damage the bellows, adapts to the packing requirements of bellows with different lengths, and has stable speed and efficiency. Figure 5 shows the automatic discharge device of automobile harness bellows.

Aiming at the accurate positioning of bellows, a method combining mechanical structure positioning and detection element detection is proposed. For the on-line identification of bellows peak position, it is suggested to use the combination of detection before tracking, Kalman tracking algorithm and development program to solve the reliability of characteristic detection. For the closed-loop control algorithm of bellows peak position, photoelectric encoder (preliminary positioning) and laser displacement sensor (accurate positioning) are used as test elements, and servo controller position closed-loop control is used to ensure the cutting peak value.

Developed car Wire harness The automatic control system of bellows cutting machine has the functions of feeding automation, cutting automation, fast non-destructive transportation, automatic detection, accurate positioning and so on. It is controlled by high-precision programmable controller, and the operation is simple; Double power feeding by stepping motor; The laser displacement sensor is fast and accurate.