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、自动上料搅拌车的特征

1、 Characteristics of automatic feeding mixer

1、行走系统由发动机通过液力变矩器、前后传动轴到前后桥。采用液压转向四驱形式，大大减小转弯半径，更适于工地上工作，特别是狭小空间施工。采用液力变矩器减少对发动机的冲击、延长了发动机的寿命。行走采用无极变速电控阀，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、液压系统采用恒功率变量柱塞泵，减少发动机的功率损耗。

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

3、搅拌罐的旋转由液压马达通过专用行星减速机带动，行星减速机的输出轴可以实现一定角度的摆动，以满足恶劣路况下搅拌罐的跳动。搅拌车的搅拌罐加有控速阀，能够精确控制搅拌罐搅拌转速。

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，按照设计好的配比由铲臂、动臂油缸、铲斗铲料后，电子称称重，自动上料。进料斗倾斜安装，确保进料流畅。用于出料的卸料槽可以旋转并通过锁紧机构固定在适当的位置。用于加长卸料槽长度的延伸料槽可折叠并放置于其固定位置，并用挂钩固定在卸料槽上。

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、进水系统带有定量自吸泵，有定量控制器设定实现自动定量进水。

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

   

6、搅拌罐通过三点固定和支撑在底架上，前端与固定在底架上的齿轮箱输出法兰联接，该法兰可以改变倾斜角度。搅拌罐通过焊装的轨道支撑在内有锥形轴承的2个滚轮上。进料、搅拌和出料由压制成型的叶片系统来完成。搅拌罐正向旋转为进料、混凝土搅拌；反向旋转，在螺旋叶片的推动下、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、自动上料搅拌车的工作原理

2、 Working principle of automatic feeding mixer

搅拌车是由多个参数决定的，用任何一个单一参数来描述一台搅拌车是不可能的。轴功率（P）、桨叶排液量（Q）、压头（H）、桨叶直径（D）及搅拌转速（N）是描述一台搅拌车的五个基本参数。桨叶的排液量与桨叶本身的流量准数，桨叶转速的一次方及桨叶直径的三次方成正比。而搅拌消耗的轴功率则与流体比重，桨叶本身的功率准数，转速的三次方及桨叶直径的五次方成正比。在一定功率及桨叶形式情况下，桨叶排液量（Q）以及压头（H）可以通过改变桨叶的直径（D）和转速（N）的匹配来调节，即大直径桨叶配以低转速（保证轴功率不变）的搅拌车产生较高的流动作用和较低的压头，而小直径桨叶配以高转速则产生较高的压头和较低的流动作用。在搅拌槽中，要使微团相互碰撞，的办法是提供足够的剪切速率。

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.

从搅拌车理看，正是由于流体速度差的存在，才使流体各层之间相互混合，因此，凡搅拌过程总是涉及到流体剪切速率。剪切应力是一种力，是搅拌应用中气泡分散和液滴破碎等的真正原因。必须指出的是，整个搅拌槽中流体各点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.

通过对剪切速率分布的研究表明，在一个搅拌槽中少存在四种剪切速率数值，它们是：实验研究表明，就桨叶区而言，无论何种浆型，当桨叶直径一定时，剪切速率和平均剪切速率都随转速的提高而增加。但当转速一定时，剪切速率和平均剪切速率与桨叶直径的关系与浆型有关。当转速一定时，径向型桨叶剪切速率随桨叶直径的增加而增加，而平均剪切速率与桨叶直径大小无关。

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.

这些有关桨叶区剪切速率的概念，在搅拌车缩小及放大设计中需要特别当心。因小槽与大槽相比，小槽搅拌车往往具有高转速（N）、小桨叶直径（D）及低叶尖速度（ND）等特性，而大槽搅拌车往往具有低转速（N)大桨叶直径（D）及高叶尖速度（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).