Application of stamping machine driven by the hott

Application of linear motor driven press

Abstract: This paper introduces the basic principle, structure and performance of the press directly driven by linear motor, as well as its detection and control methods. Compared with the traditional mechanical press, the press driven by linear motor (hereinafter referred to as electromagnetic Press) has the advantages of simple structure, small volume, light weight, short manufacturing cycle, low cost, convenient control, low noise and energy saving. At present, the scientific research prototype that Ningbo will export plastic materials and products in contact with food in 2014 will exceed US $500million kn has been studied and completed. It has passed the provincial appraisal and obtained a number of patents. It has been put into small batch production with remarkable results. The scientific research prototype of more than 100kN is being studied as a provincial key scientific and technological research project

the steel bar mechanical connection deformation measuring instrument is composed of host, high-precision electronic displacement meter, fixture, display instrument, etc. key words: linear motor; Stamping machine; Machinery

I. overview

at present, domestic and foreign stamping machinery, such as punch, need to make its punch move back and forth in a straight line when it is working. The power of the existing mechanical press (punch) comes from the rotating motor. It requires a complete set of complex conversion mechanisms to convert the rotating motion into the required linear reciprocating motion. In order to obtain sufficient punching pressure, it also needs to be equipped with a large flywheel with energy storage. Therefore, this press has many parts, complex structure, bulky volume, high noise, long production cycle, inflexible use, and is prone to personal injury accidents. The disadvantages of this mechanical stamping machine have not been fundamentally changed

the new electromagnetic punch (linear motor punch) developed in this paper uses linear motor technology to directly convert electric energy into mechanical force. It does not need any intermediate conversion mechanism to realize the reciprocating motion of the punch. Although there are similar studies at home and abroad, there are no achievements and product identification in this field at present. It has obtained a number of authorized patents and has been put into small batch production with remarkable results. Compared with the traditional mechanical stamping machine, this new electromagnetic stamping machine has simple structure; Small size and light weight; No periodic mechanical noise; Pulse work, with energy-saving effect; Stamping tonnage, frequency and speed are adjustable; There are various installation methods; It is easy to control and can realize a variety of protection functions

II. Structure and working principle

1. Basic structure

electromagnetic punch driven by linear motor, its overall structure diagram is shown in Figure 1. It is mainly divided into three parts, namely, the body part, the linear motor part and the control system part

it is composed of a workbench, a support seat for installing the motor and control system, and a ball 5, a guide column 6 and a mold base 7 to ensure accuracy; 2 and 3 in the figure are the primary and secondary of linear motor respectively; Figure 4 shows the control system of the whole machine

2. Basic working principle

the basic working principle of this structure is briefly described as follows:

plug in the power supply, start the power switch, and set the stamping tonnage. If it is automatic stamping, you need to set the stamping operation frequency, and then start the stamping button, otherwise it will be handled manually. When the button is turned on, the primary 2 of the linear motor will be powered on to generate electromagnetic force, so that the secondary 3 drives the mold base 7 to move downward to punch the workpiece. After stamping, secondary 3 returns to the initial position under the pull of reverse electromagnetic force and recovery spring, waiting for the next stamping. If the button is in the automatic continuous punching state, the punch will work continuously at the set frequency until the button is closed. Unless the safety power-off device needs to stop halfway, the punch is only controlled by the button

III. linear motor and control technology

1. Linear motor design

the key part of electromagnetic stamping machine is linear motor. In general, linear motors are often used as devices to drive intermittent operation, and the indication error of its duration is not more than ± 1%, often less than 25%. But now the linear motor is used to drive the stamping machine, its persistence rate is much higher, and it is basically in a continuous working state. Therefore, higher requirements are put forward for the design and manufacture of linear motors

first of all, in terms of the basic type and structure of linear motor, we mainly use linear induction motor, whose structure includes cylindrical type, plane double-sided type and single-sided type. We also specially designed linear motor with special structure, Such as shell dynamic secondary type [6 and other special structural types; secondly, in the design of the electromagnetic scheme, the computer is used for multi scheme optimization design; finally, some new attempts are made in the primary and secondary materials and structures. Through the above work, the performance of the linear motor is completely suitable for the working needs of the electromagnetic press.

2, the control system

the linear motor of the electromagnetic press is connected to the power supply through the contactless switch - solid state The control system of stamping machine is a very important part, which is composed of four parts: ① power supply part; ② Counting and display part; ③ Trigger driving part; ④ Automatic protection part. The block diagram of the control system is shown in Figure 2: the control system can achieve the following functions:

(1) the stamping tonnage is adjustable

(2) stroke adjustable

(3) manual and automatic stamping can be selected

(4) stamping frequency (20 ~ 300 times/min) can be selected

(5) it has various electrical, thermal and mechanical fault detection and protection functions

for the control system with the above functions, special attention should be paid to solving two problems, namely, determining the best trigger time and the best conduction time of the motor. The above two problems are mainly solved by using single chip microcomputer control circuit after computer simulation and detection. The principle block diagram of the control circuit is shown in Figure 3. Figure 4 shows the specific line

IV. test and results

we have designed and developed four prototypes of 5, 10, 31.5 and 50kN, and their test data are basically consistent with the design value. The impulse error is between 1% and 5%. We have tested and detected the blanking force of the linear motor press and the temperature rise of the press body and the primary and secondary of the linear motor. The test system is shown in Figure 5.

we also tested the pulse power and total power consumption of the operation. The test operation time is generally more than 4H. The user runs continuously for more than 8h. In the test of the force, temperature and energy consumption of the electromagnetic punch, how to accurately measure its blanking force is one of the tasks of this paper. Because the punching force of the electromagnetic punch is a kind of transient force, its punching speed is fast and the transient process is short (MS level), therefore, this paper adopts the digital signal processing technology and through the computer-aided test system, so as to accurately measure the output data. The following is an introduction to the force test system