1C31194G02現(xiàn)貨卡件模塊工控備件

在線咨詢買家必讀:

一、店鋪所有價(jià)格均不是實(shí)價(jià)，如需了解產(chǎn)品價(jià)格，請(qǐng)聯(lián)系在線客服。

二、現(xiàn)貨付款當(dāng)日發(fā)貨；期貨從付款日起開(kāi)始計(jì)算時(shí)間，貨期不含國(guó)內(nèi)外節(jié)假日。

三、買家通過(guò)快遞或物流簽收貨物后，若有異議，請(qǐng)?jiān)谑盏截浳锂?dāng)天內(nèi)提出。

1、下單前，買家需向賣家確認(rèn)價(jià)格和貨期；若買家單方面下單，則訂單視為無(wú)效；

2、下單后,買家不得更改產(chǎn)品品牌，規(guī)格型號(hào)以及數(shù)量、單價(jià)等，因買家提供產(chǎn)品規(guī)格型號(hào)錯(cuò)誤而造成錯(cuò)誤訂貨的，賣家不負(fù)責(zé)更換貨品、退貨、退款等，也不承擔(dān)因此造成的損失；

3、下單后，若無(wú)質(zhì)量問(wèn)題，不接受無(wú)理由退/換貨、退款;

4、因此產(chǎn)品生產(chǎn)廠家停產(chǎn)、升級(jí)無(wú)3C、漲價(jià)、受限制造成無(wú)法訂貨，則訂單取消，賣家不承擔(dān)任何相關(guān)法律責(zé)任；

5、因自然天氣、運(yùn)輸貨運(yùn)、政法政治原因等非賣方所能控制之客觀因素導(dǎo)致貨期延誤，賣家不承擔(dān)任何相關(guān)法律責(zé)任，由買賣雙方協(xié)商訂單是否依舊生效。

請(qǐng)各位買家知悉相關(guān)條款，如有異議，請(qǐng)咨詢解決相關(guān)疑問(wèn)！

The parameter setting of PID is the core content of the control system design of injection molding machine. It is to determine the pressure, speed, temperature PID control proportion coefficient, integration time and differential time according to the characteristics of injection molding process. There are many methods to set PID control parameters, which are summarized in two categories: one is theoretical calculation and setting. It is mainly based on the mathematical model of the action system of the injection molding machine, and the control parameters are determined by theoretical calculation. The calculation data obtained by this method may not be directly used, but also must be adjusted and modified by the actual action of injection molding machine. The second is the setting method of the action process of the injection molding machine. It mainly relies on the experience of the injection molding machine action control, and directly adjusts the pressure, speed and temperature when the injection molding machine is running. The method is simple and easy to master, and is widely used in the commissioning of the injection molding machine. The engineering setting methods of PID control parameters are mainly critical proportion method, reaction curve method and attenuation method. The three methods have their own characteristics, and their common point is to pass the test, and then adjust the PID parameters according to the experience of injection molding machine debugging. However, no matter which method is adopted, the PID parameters need to be adjusted and perfected in practice. During the field setting of injection molding, we should keep PID parameters in the order of proportion first, then integration and final differentiation. While observing the trend curve of field process value PV, slowly change PID parameters and make repeated trial until the control quality meets the requirements. In the setting of injection molding machine pressure, speed and temperature, we usually turn off integral term and differential term first, i.e. ti is set to infinity and TD is set to zero, so that it can be adjusted as pure proportion. The initial scale is set according to the empirical data, and the proportion is controlled slowly according to the PV curve, so that the system can achieve the PV curve with 4:1 attenuation oscillation, and then add the integral function. Before the integral action, the proportion should be increased to about 1.2 times of the original. The integration time ti is adjusted from large to small until the system obtains the PV curve of 4:1 attenuation oscillation again. If differential action is needed, the differential time is calculated according to td= (1/3-1/4) Ti. Then the scale can be adjusted to the original value or smaller, and then the differential time can be adjusted from small to large until the PV curve reaches satisfaction. One thing to note is that in the process of trial, if Ti and TD are to be changed, the ratio should be kept unchanged. Before finding the best setting parameters, we should analyze the trend of PV value curve, judge the change of disturbance, and then make a trial slowly. If the optimal setting parameters or parameters cannot be found after many times, and the injection molding process must be more accurate, the effectiveness of single loop PID control should be considered, and more complex PID control should be selected. It is worth noting: after the PID optimal setting parameters are determined, it can not be explained that it is always the best. When the fundamental change occurs due to external disturbance, for example, the pressure proportional valve is adjusted and cleaned, and the heating ring is replaced. In fact, if the temperature is to be precisely adjusted, different products, different back pressure and thermal inertia are different, all of them need to be adjusted! We must readjust the optimal parameters according to the needs, and it is also an important link to ensure the effectiveness of PID control. Of course, in the actual injection molding production only a period of time to carry out a verification can!