The concrete automatic loading mixer is a kind of concrete mixing truck which is suitable for small-scale engineering construction and integrates automatic feeding, mixing, transportation and automatic unloading. It is composed of high-power diesel engine, hydraulic torque converter, front and rear four-wheel drive axle, feeding device, feeding hopper, unloading hopper, lengthened discharge hopper, frame, mixing tank, planetary reducer for mixing, hydraulic system, electric control system, automatic water feeding system, etc. Automatic feeding mixer has many advantages, which can greatly improve the efficiency of production. Now we will introduce in detail the characteristics and working principle of the automatic feeding mixer.

一、自動(dòng)上料攪拌車的特征

1、 Characteristics of automatic feeding mixer

1、行走系統(tǒng)由發(fā)動(dòng)機(jī)通過液力變矩器、前后傳動(dòng)軸到前后橋。采用液壓轉(zhuǎn)向四驅(qū)形式，大大減小轉(zhuǎn)彎半徑，更適于工地上工作，特別是狹小空間施工。采用液力變矩器減少對(duì)發(fā)動(dòng)機(jī)的沖擊、延長了發(fā)動(dòng)機(jī)的壽命。行走采用無極變速電控閥，方便操控。

1. The walking system from the engine through the hydraulic torque converter, front and rear transmission shaft to the front and rear axle. The hydraulic steering four-wheel drive is adopted to greatly reduce the turning radius, which is more suitable for working on the construction site, especially in the narrow space. The hydraulic torque converter is used to reduce the impact on the engine and prolong the service life of the engine. Stepless variable speed electric control valve is used for walking, which is convenient to control.

2、液壓系統(tǒng)采用恒功率變量柱塞泵，減少發(fā)動(dòng)機(jī)的功率損耗。

2. The constant power variable piston pump is used in the hydraulic system to reduce the power loss of the engine.        

3、攪拌罐的旋轉(zhuǎn)由液壓馬達(dá)通過專用行星減速機(jī)帶動(dòng)，行星減速機(jī)的輸出軸可以實(shí)現(xiàn)一定角度的擺動(dòng)，以滿足惡劣路況下攪拌罐的跳動(dòng)。攪拌車的攪拌罐加有控速閥，能夠精確控制攪拌罐攪拌轉(zhuǎn)速。

3. The rotation of the mixing tank is driven by the hydraulic motor through a special planetary reducer. The output shaft of the planetary reducer can swing at a certain angle to meet the beating of the mixing tank under bad road conditions. The mixing tank of the mixer is equipped with a speed control valve, which can accurately control the mixing speed of the mixing tank.

4、干料上料，按照設(shè)計(jì)好的配比由鏟臂、動(dòng)臂油缸、鏟斗鏟料后，電子稱稱重，自動(dòng)上料。進(jìn)料斗傾斜安裝，確保進(jìn)料流暢。用于出料的卸料槽可以旋轉(zhuǎn)并通過鎖緊機(jī)構(gòu)固定在適當(dāng)?shù)奈恢?。用于加長卸料槽長度的延伸料槽可折疊并放置于其固定位置，并用掛鉤固定在卸料槽上。

4. Dry material loading, according to the designed proportion, the shovel arm, boom cylinder, bucket shovel, electronic weighing, automatic feeding. The feeding hopper is inclined to ensure smooth feeding. The discharge chute for discharging can be rotated and fixed in proper position by locking mechanism. The extended chute for lengthening the length of the discharge chute can be folded and placed in its fixed position, and is fixed on the discharge chute with a hook.   

       

5、進(jìn)水系統(tǒng)帶有定量自吸泵，有定量控制器設(shè)定實(shí)現(xiàn)自動(dòng)定量進(jìn)水。

5. The water inlet system is equipped with quantitative self-priming pump and quantitative controller setting to realize automatic quantitative water inflow.    

   

6、攪拌罐通過三點(diǎn)固定和支撐在底架上，前端與固定在底架上的齒輪箱輸出法蘭聯(lián)接，該法蘭可以改變傾斜角度。攪拌罐通過焊裝的軌道支撐在內(nèi)有錐形軸承的2個(gè)滾輪上。進(jìn)料、攪拌和出料由壓制成型的葉片系統(tǒng)來完成。攪拌罐正向旋轉(zhuǎn)為進(jìn)料、混凝土攪拌；反向旋轉(zhuǎn)，在螺旋葉片的推動(dòng)下、混凝土由出料口出料。

6. The mixing tank is fixed and supported on the underframe through three points, and the front end is connected with the gearbox output flange fixed on the underframe. The flange can change the tilt angle. The mixing tank is supported on two rollers with tapered bearings through welded rails. The feeding, mixing and discharging are completed by pressing blade system. The forward rotation of the mixing tank is for feeding and concrete mixing; for reverse rotation, the concrete is discharged from the discharge outlet under the push of spiral blades.

二、自動(dòng)上料攪拌車的工作原理

2、 Working principle of automatic feeding mixer

攪拌車是由多個(gè)參數(shù)決定的，用任何一個(gè)單一參數(shù)來描述一臺(tái)攪拌車是不可能的。軸功率（P）、槳葉排液量（Q）、壓頭（H）、槳葉直徑（D）及攪拌轉(zhuǎn)速（N）是描述一臺(tái)攪拌車的五個(gè)基本參數(shù)。槳葉的排液量與槳葉本身的流量準(zhǔn)數(shù)，槳葉轉(zhuǎn)速的一次方及槳葉直徑的三次方成正比。而攪拌消耗的軸功率則與流體比重，槳葉本身的功率準(zhǔn)數(shù)，轉(zhuǎn)速的三次方及槳葉直徑的五次方成正比。在一定功率及槳葉形式情況下，槳葉排液量（Q）以及壓頭（H）可以通過改變槳葉的直徑（D）和轉(zhuǎn)速（N）的匹配來調(diào)節(jié)，即大直徑槳葉配以低轉(zhuǎn)速（保證軸功率不變）的攪拌車產(chǎn)生較高的流動(dòng)作用和較低的壓頭，而小直徑槳葉配以高轉(zhuǎn)速則產(chǎn)生較高的壓頭和較低的流動(dòng)作用。在攪拌槽中，要使微團(tuán)相互碰撞，的辦法是提供足夠的剪切速率。

The mixer is determined by many parameters. It is impossible to describe a mixer with any single parameter. Shaft power (P), blade discharge (q), head (H), blade diameter (d) and stirring speed (n) are the five basic parameters to describe a mixer. The discharge volume of the blade is directly proportional to the flow standard of the blade itself, the first power of the blade speed and the third power of the blade diameter. The shaft power consumed by stirring is directly proportional to the specific gravity of the fluid, the power criterion of the blade itself, the third power of the rotating speed and the fifth power of the blade diameter. Under the condition of certain power and blade form, the discharge volume (q) and head (H) can be adjusted by changing the matching of diameter (d) and speed (n) of blades, that is, large diameter blades with low speed (ensuring the same shaft power) produce higher flow effect and lower head, while small diameter blades with high speed produce higher head and lower head Mobility. In a stirred tank, the only way to make the pellets collide with each other is to provide sufficient shear rate.

從攪拌車?yán)砜矗怯捎诹黧w速度差的存在，才使流體各層之間相互混合，因此，凡攪拌過程總是涉及到流體剪切速率。剪切應(yīng)力是一種力，是攪拌應(yīng)用中氣泡分散和液滴破碎等的真正原因。必須指出的是，整個(gè)攪拌槽中流體各點(diǎn)剪切速率的大小并不是一致的。

From the view of mixer mechanism, it is the existence of fluid velocity difference that makes the fluid layers mix with each other. Therefore, the shear rate of fluid is always involved in the mixing process. Shear stress is a kind of force, which is the real cause of bubble dispersion and droplet breakup in stirring applications. It must be pointed out that the shear rate of fluid in the whole stirred tank is not the same.

通過對(duì)剪切速率分布的研究表明，在一個(gè)攪拌槽中少存在四種剪切速率數(shù)值，它們是：實(shí)驗(yàn)研究表明，就槳葉區(qū)而言，無論何種漿型，當(dāng)槳葉直徑一定時(shí)，剪切速率和平均剪切速率都隨轉(zhuǎn)速的提高而增加。但當(dāng)轉(zhuǎn)速一定時(shí)，剪切速率和平均剪切速率與槳葉直徑的關(guān)系與漿型有關(guān)。當(dāng)轉(zhuǎn)速一定時(shí)，徑向型槳葉剪切速率隨槳葉直徑的增加而增加，而平均剪切速率與槳葉直徑大小無關(guān)。

The results show that there are at least four kinds of shear rate values in a stirred tank. They are: the experimental results show that the maximum shear rate and the average shear rate increase with the increase of the rotating speed, regardless of the size of the impeller. However, when the rotating speed is constant, the relationship between the maximum shear rate and the average shear rate and the blade diameter is related to the pulp shape. When the rotating speed is constant, the maximum shear rate of radial blade increases with the increase of blade diameter, but the average shear rate has nothing to do with the blade diameter.

這些有關(guān)槳葉區(qū)剪切速率的概念，在攪拌車縮小及放大設(shè)計(jì)中需要特別當(dāng)心。因小槽與大槽相比，小槽攪拌車往往具有高轉(zhuǎn)速（N）、小槳葉直徑（D）及低葉尖速度（ND）等特性，而大槽攪拌車往往具有低轉(zhuǎn)速（N)大槳葉直徑（D）及高葉尖速度（ND）等特性。

These concepts about the shear rate in the blade zone need to be taken care of in the design of the mixer. Compared with the large tank, the small tank mixer often has the characteristics of high speed (n), small blade diameter (d) and low blade tip speed (nd), while the large tank mixer often has the characteristics of low speed (n), large blade diameter (d) and high blade tip speed (nd).