Metal sheet stretching energy-saving method

Abstract

The invention discloses a metal sheet stretching energy-saving method. The metal sheet stretching energy-saving method is applied to a stretching machine with a fixed blank holder and a vertically-moving male die core. The method includes the following steps that firstly emptying and blank pressing are conducted, wherein a metal sheet is coated with lubricating fluid and is placed on the blank holder, a female die moves downwards under drive of a blank pressing oil cylinder, and blanks are pressed; secondly, stretching forming is conducted, wherein the male die core moves upwards relative to the blank holder under drive of a stretching oil cylinder, the male die core and the female die are matched to finish integral stretching forming work; in the process, a servo hydraulic closed-loop control system linearly adjusts blank pressing force and stretching force in real time according to the requirements of produced products; thirdly, discharging is conducted, wherein the female die and the male die core simultaneously act, the female die is moved upwards and reset, the male die core is moved downwards and reset, and the products which are acquired after stretching forming are exposed and placed on the blank holder. The method has the following advantages that energy is saved, and production cost is reduced; the speed is high, and production efficiency is improved; equipment operation and maintenance cost is reduced; the defective rate of the products is reduced.

Description

Technical field [0001] The invention relates to the technical field of stretching technology, in particular to a metal sheet stretching energy-saving method with linearly controllable stretching force and blank holder force. Background technique [0002] At present, most of the hydraulic drawing machines adopt the forward drawing process, such as figure 1 , 2 As shown, the existing stretching machine generally includes a frame 11, a stretching cylinder 13 installed above the frame and driving the die 12 to move downward, and a blanking cylinder 15 installed below the frame and having a blank holder 14 , Hydraulic drive system and controller. Driven by the stretching cylinder 13, the blank holder 14 can move down the punch core 16 with respect to the worktable 17. During this process, the punch core 16 does not move, but The blank holder 14 moves downward relative to the male core 16 to achieve a stretching effect. In this mode, the total pressure F provided by the master cylinde...

AI Technical Summary

Problems solved by technology

The use of a relief valve enables the F 1 , F 2 The open-loop control solves the problem of F during product stretching 总 not adjustable while F 1 , F 2 Contradictions that require real-time regulation, but excessive back pressure F 3 Generated back pressure loss power W 3 It causes higher energy consumption, and at the same time makes the temperature of the hydraulic oil easy to rise, and also increases the probability of damage to machine parts

[0007] 2. To complete the entire stretching process, the movement stroke of the die is relatively long, which requires higher requirements on the oil cylinder and increases the cost; in actual production, due to the long stroke, the movement of the blank holder cylinder takes a long time, resulting in low production efficiency

[0008] 3. Due to the non-adjustable back pressure, the defective rate of products during production is high: during the stretching process, if the pressure is small, the product is easy to wrinkle and twist; if the pressure is high, the product is easy to crack

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