An Introduction to Check Fixtures

Definition of Check Fixture

1. The inspection tool is a kind of special inspection equipment used to measure and evaluate the size, shape and position characteristics of parts.

2. Function of Check Fixture

① Online inspection of parts is realized through inspection tools; Check the part surface and periphery by visual inspection, measuring table or caliper, and visually inspect the holes with different properties on the parts and the connection positions between the parts and the parts by means of inspection pin or visual inspection, so as to ensure the quick judgment of the part quality status during trial production and starting production.

② For some extremely important functional dimensions on the part, the inspection tool can also be used for numerical detection. Generally, the precise coordinate values of parts based on the body coordinate system cannot be obtained directly with the help of the inspection tool, but can be obtained by placing the parts on the inspection tool and measuring with the CMM. When designing the structure of modern inspection tools, it is also considered that they can be used as measuring supports.

Sheet metal parts inspection tool plays a decisive role in the quality control of parts.

Classification of  Check Fixtures:

According to the detection object, it can be divided into stamping single product inspection tool, part assembly inspection tool and combined inspection tool.

Punching single product inspection tools and assembly inspection tools are mainly used to complete the measurement in the product processing process. They often need to detect the profile and emphasize the continuity of the surface.

The combined inspection tool is mainly used to detect the mutual matching relationship of sub assemblies and the matching accuracy after assembly, and mainly plays the role of measuring support; As shown in the figure below.

Basic Structure of Parts Check Fixture:

1) Frame base

2) Positioning device (locating pin, locating block)

3) Clamping device (clamp, magnet, etc.)

4) Body or body (inspection surface, non inspection surface)

5) Profile template

6) Profile movable block

7) Detection device (detection pin, feeler gauge, scribed line, dial gauge, etc.)