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As one of the important tools for product assembly, the bolt tightening tool has a great influence on the assembly quality and assembly efficiency of the product. How to choose the appropriate tightening tool according to the actual assembly space and efficiency requirements of the product are very important.

At present, there are many kinds of bolt-tightening tools, and there is no unified standard for the classification of tools. There are big differences between brands of bolt-tightening tools in terms of shape, size, weight, and other parameters. Moreover, the service life of each brand is different, which makes the selection of bolt-tightening tools difficult.

When choosing a bolt tightening tool, you should first understand the basic principle and related parameters of the bolt tightening tool, then consider the product structure space characteristics and assembly efficiency requirements and select the appropriate tightening tool based on the bolt tightening tool and product structure characteristics.

In addition, the application of bolt-tightening tools requires attention to daily maintenance, and timely maintenance will greatly improve the life of the tool and reduce the operating cost of the enterprise.

Introduction to Bolt Tightening Tools

Classification of tools

There are many types of bolt-tightening tools, and there is no unified standard for the classification of tools. According to whether the output torque of the tool can be set to a certain value, it can be divided into ordinary tightening tools and constant torque tightening tools. At present, according to the power source of the tool and whether it is a fixed torque, it is more common to classify it into electric screwdrivers, battery screwdrivers, hydraulic screwdrivers, pneumatic fixed torque air guns, and pneumatic ordinary air guns.

Power source:

Electric energy: electric tightening machine, hydraulic tightening machine, battery ordinary tightening wrench, battery constant torque tightening wrench

Air energy: pneumatic ordinary air gun, pulse type pneumatic constant torque air gun, mechanical pneumatic constant torque air gun

Electric tightening machine

Electric tightening machines specify torque tightening machines (shafts), which are divided into single-axis and multi-axis combined tightening machines. When working, it outputs a constant torque value, and the power source is electric energy. The schematic diagram of its structure and principle are shown in Figure 2 and Figure 3.

Battery tightening wrench

The battery tightening wrench is divided into a battery-fixed torque tightening wrench and a battery-ordinary tightening wrench. It is distinguished by whether the fixed torque value is output during operation. The power source is electric energy. The schematic diagram of its structure and principle are shown in Figure 4 and Figure 5.

Hydraulic tightening machine

Hydraulic tightening machine with specified torque The hydraulic tightening machine outputs a constant torque value when working, and the power source is electric energy. The schematic diagram of its structure and principle are shown in Figure 6 and Figure 7.

Pneumatic fixed torque air gun

Pneumatic constant-torque air gun The specified torque tightening air gun is divided into pulse type pneumatic constant-torque air gun and mechanical pneumatic constant-torque air gun according to different torque increasing units. When working, it outputs a constant torque value, and the power source is gas energy. The schematic diagram of its structure and principle are shown in Figure 8 and Figure 9.

Pneumatic ordinary air gun

Pneumatic ordinary air gun refers to the non-fixed torque tightening air gun and outputs a non-fixed torque value during operation. The power source is air energy. The schematic diagram of its structure and principle is shown in Figure 10 and Figure 11.

Key Metrics for the Tool

Before choosing a bolt-tightening tool, you need to understand the key parameters of the tool to prepare for accurate selection.

The parameter indicators are as follows
Torque range: the torque range of the output shaft of the bolt-tightening tool
Torque accuracy: The torque accuracy of the output shaft of the bolt-tightening tool
Stability: The number of times the bolting tool is continuously tightened without an accuracy check
Square head speed: the idle speed of the output shaft of the bolt-tightening tool
Working air pressure: the working air pressure range required by the bolt tightening tool (pneumatic) in normal working condition
Tool noise: the noise made by the bolt tightening tool when it is working

Bolt Tightening Tool Selection Guide

General principles of tool selection guidance

When selecting a bolt-tightening tool, it should be comprehensively considered from the four aspects of quality (Q), safety (S), efficiency (R), and cost (C).

Quality

The quality of bolt tightening is determined by the torque accuracy and stability of the tool. When selecting the model, focus on the tool’s torque accuracy and stability to ensure that the torque accuracy and stability of the bolt-tightening tool meet the process requirements.

Safety

Bolt-tightening tools should meet the relevant safety and environmental protection requirements of the country and the company. For example, the noise of bolt-tightening tools should meet the noise value specified by the company (≤85 decibels).

Efficiency

The tightening efficiency of the bolt-tightening tool should meet the production cycle requirements. For tools that need to be equipped with a robotic arm, the form and structure of the robotic arm must be reviewed and confirmed.

Cost

The cost of bolt-tightening tools should take into account tool depreciation costs, tool maintenance costs, and energy costs. In addition to the depreciation cost of the tool, the maintenance cost of the tool should be considered. When bidding, the manufacturer should be asked to indicate the maintenance regulations of the tool. At the same time, indicate the specifications, brands, unit prices, lifespan, and other information of various vulnerable and damaged parts, and ask the manufacturer to provide maintenance plans if necessary.

Tool selection guide

Each type of bolt-tightening tool has its own characteristics. While considering the four aspects of quality (Q), safety (S), efficiency (R), and cost (C), the type selection should be comprehensively considered in combination with the characteristics of bolt-tightening tools and actual working conditions.

In the end

Although the technical parameters of various brands of bolt-tightening tools are not much different, there are certain differences in the shape, size, weight, life, and corresponding supporting equipment of each brand, which makes it more difficult to choose a suitable tightening tool.

Judging from the current use of tightening tools, the main reason for the inapplicability of bolt tightening tools is not the technical parameters of the tool itself, but that the selected tool cannot better combine the spatial characteristics and assembly efficiency requirements of the product itself. This makes the bolt-tightening tool problematic in terms of flexibility of operation.

Therefore, only by selecting the appropriate bolt-tightening tool can the value of the tool itself be exerted, and the product quality and product assembly efficiency can be improved.