Seeing this problem, I think we will have questions. Isn't it a good thing that the extension arm works quickly throughout the project? Why does Xiaobian say this is a problem? In fact, the speed mentioned here is compared with the set speed of your excavator. Some excavators have been modified to install the telescopic boom of the excavator, which is different from the speed of the equipment itself, resulting in the uncontrollable telescopic boom. So how to solve this problem? The following contents hope to help you answer this question!

1.原因:

1. Reasons:

挖掘机配有加长臂工作装置，移动臂长，斗杆长，工作范围大，容易发生事故。当挖掘机的工作速度设定为正常工作速度时，移动臂和斗杆线的速度太快，操作人员无法控制。因此，有必要加长臂工作装置移动过快的问题。

The excavator is equipped with an extended arm working device, with long moving arm, long bucket rod and large working range, which is prone to accidents. When the working speed of the excavator is set to the normal working speed, the speed of the moving arm and stick line is too fast for the operator to control. Therefore, it is necessary to solve the problem that the working device of the lengthening arm moves too fast.

2.安徽华体会国际 改进方案的选择:

2. Selection of improvement scheme of Anhui lengthening arm excavator:

挖掘机工作装置的主控制阀由先导压力油控制。先导压力油进入主控制阀阀芯端，推动阀芯左右移动，打开主控制阀回路。它可以通过减小主控制阀的尺寸来改进。

The main control valve of the excavator working device is controlled by pilot pressure oil. The pilot pressure oil enters the valve core end of the main control valve, pushes the valve core to move left and right, and opens the main control valve circuit. It can be improved by reducing the size of the main control valve.

根据主控制阀阀芯行程和流量面积曲线可以看出，主控制阀阀芯开启过程逐渐加大，阀芯行程越大，主控制阀的流量面积越大。当阀芯移动到冲程的末端时，开口达到，通过主控制阀的流量达到。

According to the main control valve spool stroke and flow area curve, it can be seen that the opening process of the main control valve spool gradually increases. The larger the spool stroke, the larger the flow area of the main control valve. When the spool moves to the end of the stroke, the opening is reached and the flow through the main control valve is reached.

从而，主控制阀阀芯限度，可以减少阀芯行程。当主滑阀控制左、右端移动,控制的主要控制滑阀不能达到完整的中风,主控阀阀门开度不能达到,可以减少流动区域,降低液压缸的流量,从而减少工作设备的速度。

Thus, the limit of the main control valve spool can reduce the spool stroke. When the main slide valve controls the movement of the left and right ends, the main control slide valve can not reach the complete stroke, and the valve opening of the main control valve can not reach, which can reduce the flow area and reduce the flow of the hydraulic cylinder, so as to reduce the speed of the working equipment.

3.实现和验证:

3. Implementation and verification:

根据以上分析，通过对主控制阀的测量，确定阀芯的全行程为10mm。主控制阀阀芯行程限位接头安装后，工作装置转速明显下降。

According to the above analysis, through the measurement of the main control valve, it is determined that the full stroke of the valve core is 10mm. After the installation of the travel limit joint of the valve core of the main control valve, the speed of the working device decreases significantly.

以动劈落差为例，进行了阀芯行程限位接头安装后的操纵性和协调性试验。发现当阀芯位移限制关节安装了2.5毫米的旅行限制,动臂下降的指标和整个机器的可操作性和协调达到挖掘机动臂的下行速度的标准工作设备,可以满足挖掘机的需求。

Taking the drop of moving wedge as an example, the operability and coordination test of valve core stroke limit joint after installation is carried out. It is found that when the travel limit of 2.5mm is installed in the valve core displacement limit joint, the index of boom descent and the operability and coordination of the whole machine can reach the standard working equipment of the downward speed of the excavator boom, which can meet the needs of the excavator.

利用以上方法对挖掘机的伸缩臂进行改进，可以工作装置速度过快的问题，你了解了吗?

Using the above methods to improve the telescopic arm of excavator can solve the problem of too fast working device. Do you understand?