35results about How to "Welding state is stable" patented technology

A squeezing detection control method is provided for consumable electrode arc welding in which a cycle of arc generation and short-circuiting is repeated between a consumable electrode and a base metal. First, squeezed droplet is detected as a premonitory sign of arc recurrence at the end of the short-circuiting. This detection is based on a fact that a squeeze detection reference value is attained by a differential value of the voltage or resistance between the consumable electrode and the base metal. Then, a welding current supplied to a short-circuit load is rapidly decreased upon detection of the squeezed droplet. Upon recurrence of the arc, the welding current is increased. This arc recurrence is detected by a fact that the differential value attains an arc recurrence reference value which is greater than the squeeze detection reference value.

The invention provides a short circuit judgment method for electrode fused arc welding, by which even the electric cable for welding is long in the electrode fused arc welding, whether the welding filament and the base metal in short circuit status or arc generation status can be accurately determined, and welding of high quality can be executed. A welding voltage (Vw) is compared with a short circuit standard value (Vt), a short circuit status is judged when the welding voltage (Vw) is lower than the short circuit standard value (Vt), while an arc generation status is judged when the welding voltage (Vw) is higher than the short circuit standard value (Vt). The short circuit standard value (Vt) varies according to the welding current value, and an upper limit is set in the arc generation status, which is a function of the welding current. Therefore, error judgment of short circuit status caused by welding voltage sudden decrease after arc generation can be prevented.

The invention provides a necking detection and control method of melting electrode and electric arc welding in order to improve the detection precision of the necking during the melting of electrode and electric arc. The necking of droplets can be detected in a manner that the change of a resistance value between a melting electrode (1) and a base material (2) reaches to a necking detection reference value (Vtn). If necking is detected, the welding current is reduced, and output control can be conducted under the state of low current value, regenerating electric arc. The necking detection time is calculated from the detection time of the necking phenomenon to the regeneration of electric arc based on each short circuit. When the necking detection time is below a lower limit time, one is subtracted from a count value. When the necking detection time is above an upper limit time, one is added to the count value. When the count value reaches to a negative reference value, the necking detection reference value (Vtn) is reduced. When the count value reaches to a positive reference value, the necking detection reference value (Vtn) is increased. Accordingly, as the necking detection reference value (Vtn) can be appropriate, the detection precision of the necking can be improved.

Provided is an arc welding control method that performs welding by alternately switching feed rate (Fw) for welding wire (1) between a forward feed period and a reverse feed period, controlling welding voltage (Vw) on the basis of a voltage setting value, and repeating a short period and an arc period, wherein a smoothed value for welding voltage (Vw) is detected and a cycle (Tf) of the feed rate (Fw) is feedback controlled such that this smoothed value for welding voltage and the voltage setting value are the same. Thereby, the cycle (Tf) of the feed rate (Fw) is made appropriate in correspondence with changes in the metal transfer mode accompanying changes in voltage setting value; therefore, it is possible to control occurrences of synchronization offsets in the cycle of forward feed and reverse feed for the feed rate (Fw) and the cycle of the short period and the arc period, and maintain stable welding conditions.

The invention provides a welding source output control method which suppresses the prolonging of electric arc period caused by the spray out of gases from a weld pool during the carbon dioxide electric arc welding. The welding source output control method controls the output of the welding source, which is used for the electric arc welding during the repeated short circuit period and the electric arc period between a welding wire and a base metal, through the feedback control of the welding voltage. During the electric arc period of t3-t5, the variation of the welding voltage (Vw) repeatedly exceeds the preset reference valve more than twice (t41, t42, and t43), the welding current (Iw) is reduced to the starting time (t5) of a next short circuit period. Therefore, the welding current (Iw) is immediately reduced when the spray out of gases is determined, so that the prolonging the electric arc period can be suppressed and the increasing of sputtering generation can be prevented.

The invention provides a method for controlling AC pulse electric arc welding, which is intended to maintain a stable welding state even an electrode negative polarity current ratio is set to be a large value in sacrificial electrode AC pulse electric arc welding. Therefore, a background current is powered during the electrode negative polarity base value, an electrode negative polarity peak current (Ipn) is powered during the electrode negative polarity peak value (Tpn), a peak current is powered during the electrode positive polarity peak value, a background current is powered during the electrode positive polarity base value. A short circuit occurs during the electrode positive polarity peak value. When a value of a short circuit generating time point relative to a molten drop dimension is lower than a reference value , the current during the short circuit is added, and when the value relative to the molten drop dimension is larger than the reference value, the value is converted in the electrode positive polarity peak value period at the short circuit generating time point. Therefore, molten drop transition is smoothly performed irrespectively with the molten drop dimension, thereby maintaining the stable welding state.

The invention provides a control method for consumable electrode arc welding. If constriction of molten droplet is detected, a welding current powered to a short circuit load is reduced so as to generate a constriction detection and control of the arc again. A feedback control (feed speed variable control) for the feed speed (Fw) is carried out according to a manner of a welding current smoothed value (Iav) equal to a predetermined current set value, so as to weld. The control method comprises an action mode for acting the constriction detection control and a forbidden mode for forbidding the constriction detection control. A transition response time (T1) of the feedback control in the action mode is longer than that in the forbidden mode. Therefore, the feed speed (Fw) changes slowly in relative to the change of a distance between a power chip and a base material, thereby keeping the welding state stably. The method can inhibit that the welding state becomes unstable when the constriction detection control acts together with the feed speed variable control at a constant welding current.

A consumable electrode arc welding method includes the detecting of a constriction formed in a molten droplet of the welding wire so as to reduce the welding current, the detecting of a smoothed value of the welding current, and the feedback controlling of the feed rate of the welding wire so as to make the smoothed value of the welding current correspond to a predetermined current setting value. The constriction detection is performed repetitively in a predetermined cycle.

In each time of the repetition, the length of a constriction time, from the constriction detection till the arc generation, is measured. The number of constriction time lengths falling outside a predetermined range is counted. When the counted number is not less than a reference number, the transient response time of the feedback control is made longer.

The invention discloses a connecting method for a connecting structure of a reservoir and an air conditioner compressor and belongs to the technical field of refrigeration parts. The connecting structure comprises a reservoir body and a compressor shell. The reservoir body is provided with a reservoir air outlet iron pipe. A second flange is welded to the reservoir air outlet iron pipe and is provided with a convex ring. A compressor cylinder is arranged in the compressor shell and is provided with an air inlet. A pump air suction pipe is arranged in the air inlet. The end of the pump air suction pipe is pressed into the air inlet of the compressor cylinder in an interference fit mode. The turned edge of the pump air suction pipe abuts against a first flange and the second flange. The first flange, the turned edge of the pump air suction pipe and the second flange can be combined through one time of welding. Meanwhile, the second flange is arranged as a welding clamping point, thus welding of the first flange and the second flange is convenient, the second flange is provided with the convex ring, electric currents can be focused conveniently during electric resistance welding, andwelding quality is improved.