A comprehensive testing fixture for a longitudinal beam of an automobile front subframe

Abstract

A kind of automobile front subframe longitudinal beam comprehensive testing fixture, belong to detection tool technical field, it is characterized by: it includes with support foot platform, datum, detection surface, through gauge and quick pressure clamp.Detection datum unit is by one main positioning pin, two bottom surface auxiliary positioning block, one side surface auxiliary positioning block constitute;Groove detection unit is used to detect the position and depth of groove on workpiece;Profile contour detection unit is used to detect the profile of workpiece side surface, bottom surface and the gap between datum surface;Length detection unit detects the total length of workpiece or end surface position through end surface detection surface and through gauge;Sectional dimension detection unit adopts special through gauge sample plate.The beneficial effects are: integration is high, positioning is accurate, operation is simple, cost benefit is good.

Description

Technical Field

[0001] This utility model belongs to the technical field of automotive parts testing tools. Background Technology

[0002] The front subframe longitudinal beam is a critical structural component in the automotive chassis system. The dimensional accuracy of its welded assembly directly affects the assembly quality with components such as the body, engine, and suspension, as well as the overall vehicle performance. Currently, the inspection of the subframe longitudinal beam primarily utilizes coordinate measuring machines (CMMs) or single-function inspection fixtures. While CMMs offer high precision, they suffer from low efficiency and high cost, failing to meet the demands of rapid, full inspection of every product on the production line. Single-function fixtures, on the other hand, can only inspect individual dimensions or surfaces, lacking the comprehensive assessment of critical mounting holes, contours, and the relative positions of assemblies. This results in incomplete inspection items and significant repeatability errors. Utility Model Content

[0003] The purpose of this utility model is to provide a comprehensive inspection tool for the longitudinal beams of the front subframe of automobiles, which can realize rapid, accurate and comprehensive online inspection of the front subframe longitudinal beam assembly, effectively improving inspection efficiency and consistency.

[0004] The technical solution of this utility model is:

[0005] It includes a platform with support feet, a reference, a test surface, go / no-go gauges, and quick clamps.

[0006] The support platform is a rectangular platform as the main body, with four square thick steel plates welded and fixed to the bottom as support legs. Three cylindrical calibration reference columns are fixed to the support platform with countersunk screws, and four lifting columns are fixed to the support platform with screws. The lifting columns are variable diameter cylinders, with the outer diameter being the largest, the middle diameter being the smallest, and the inner diameter being in between. The inner diameter has milled planes on the top and bottom to facilitate bolt tightening.

[0007] The inspection datum unit consists of a main locating pin, two bottom auxiliary locating blocks, and one side auxiliary locating block. The main locating pin is fixed to the bottom inspection surface with countersunk screws. The main locating pin is a square column at the bottom and a cylindrical shape at the top, with the top of the cylinder rounded. The two square bottom auxiliary locating blocks are fixed to the bottom inspection surface with countersunk screws. The square auxiliary locating block is fixed to the side inspection surface with countersunk screws. The workpiece is fixed by three top quick-release clamps and one side quick-release clamp, which is used for six-degree-of-freedom positioning and fixing of the workpiece. This datum is designed based on the key features of the workpiece's GD&T (Geometric Dimensions and Tolerances) drawing.

[0008] The groove detection unit is used to detect the position and depth of grooves on a workpiece; the groove position detection block is connected to the axially rotating movable support arm by screws, and the axially rotating movable support arm is hinged to the groove detection block support seat by a stainless steel shaft and two copper sleeves; the groove detection block support seat is fixed to the support foot platform by bolts; the go-no-go depth gauge detects the depth of the pit in the workpiece.

[0009] The profile inspection unit is used to inspect the profile of the workpiece's sides and bottom surface and the gap between them and the reference surface. The side and bottom inspection surfaces are rectangular thick plates connected to the support platform by screws. The bottom and side inspection surfaces are checked against go / no-go gauges for compliance. A tool gauge is used to inspect the profile of the upper plane.

[0010] The length detection unit detects the total length of the workpiece or the position of the end face by using the end face detection surface and the go / no-go gauge; the cross-sectional dimension detection unit uses a dedicated go / no-go template to quickly inspect the height and width of a specific cross-section of the workpiece.

[0011] The beneficial effects of this utility model are:

[0012] High integration: By integrating the five major inspection units onto the same platform, it enables simultaneous inspection of key mounting holes, contours, lengths, and cross-sectional dimensions of the subframe longitudinal beams in a single clamping operation. All key items can be inspected in one clamping operation, greatly improving inspection efficiency.

[0013] Precise positioning: The combination of main positioning pins and auxiliary positioning blocks ensures the accuracy and repeatability of the positioning of the workpiece being measured, reducing measurement errors.

[0014] Easy to operate: Testers do not need professional measurement knowledge and can complete the test by simply judging whether it is open or closed, which reduces the difficulty of operation and dependence on personnel.

[0015] Cost-effective: The structure is relatively simple, the manufacturing cost is much lower than that of a coordinate measuring machine, and it is specifically designed for certain products. It is very suitable for batch full inspection on the production site, ensuring stable and controllable product quality. Attached Figure Description

[0016] Figure 1 This is the front view of the present invention;

[0017] Figure 2 This is a top view of the present invention;

[0018] Figure 3 This is a three-dimensional schematic diagram of the overall structure. Detailed Implementation

[0019] The present invention will be further described below with reference to the accompanying drawings.

[0020] like Figure 1-3As shown, 1 is the support foot platform, 2 is the hoisting column, 3 is the calibration reference column, 4 is the upper quick clamp, 5 is the upper clamp support seat, 6 is the side quick clamp, 7 is the side clamp support seat, 8 is the side inspection surface, 9 is the bottom inspection surface, 10 is the end inspection surface, 11 is the cylindrical main positioning pin, 12 is the bottom auxiliary positioning block, 13 is the side auxiliary positioning block, 14 is the groove position inspection block, 15 is the go / no-go depth gauge, 16 is the groove inspection block support seat, 17 is the go / no-go gauge, 18 is the H-shaped cross-section inspection template, 19 is the manually rotated axial rotation movable support arm, and 20 is the knife-edge go / no-go gauge.

[0021] Its structural working principle is: See Figures 1-3 This utility model discloses a comprehensive inspection fixture for the longitudinal beam of a front subframe of an automobile, mainly comprising a support platform 1. The upper surface of the support platform 1 is precision ground and engraved with reference lines. The bottom of the support platform 1 has four lifting columns 2 for easy transfer of the fixture. The support platform 1 has three calibration reference columns 3 serving as the manufacturing and inspection references for the entire fixture. The inspection reference unit consists of a cylindrical main locating pin 11, two bottom auxiliary locating blocks 12, and a side auxiliary locating block 13. Through the cooperation of these components with the workpiece reference holes and support surfaces, the workpiece is fully positioned with six degrees of freedom. After the workpiece is positioned, three upper quick-clamping clamps 4 mounted on the upper clamping clamp support 5 and one side quick-clamping clamp 6 mounted on the side clamping clamp support 7 are used to secure the workpiece.

[0022] The groove position dimension detection unit is fixed to the axially rotating movable support arm 19 by the groove position detection block 14. The axially rotating movable support arm 19 is hinged to the groove detection block support seat 16 via a stainless steel rotating shaft and two copper sleeves. The copper sleeves serve as bearings to reduce friction and are also used for axial positioning, ensuring that the support arm 19 rotates flexibly without axial movement. The groove depth is detected using a go-no-go depth gauge 15.

[0023] The profile inspection unit uses go / no-go gauge 17 to check whether the gap between the workpiece and the side inspection surface 8 is qualified; uses go / no-go gauge 17 to check whether the gap between the workpiece and the bottom inspection surface 9 is qualified; and uses knife-edge go / no-go gauge 20 to check whether the gap between the workpiece profile and the upper edge of the side inspection surface 8 is qualified.

[0024] The component length detection unit uses go / no-go gauge 17 to check whether the gap between the end face of the workpiece and the end face detection surface 10 is qualified.

[0025] The section height and width unit uses two H-shaped section inspection templates 18 to be fitted onto the workpiece section. The height and width dimensions of the section are checked by judging whether the "through end" can be fitted smoothly and the "stop end" cannot be fitted.

[0026] The inspection procedure is as follows:

[0027] I. Preparations:

[0028] Clean the measuring surfaces of the support platform 1 and all measuring elements to ensure they are free of dirt and chips. Check that all go / no-go gauges, measuring blocks, and templates are intact and clean.

[0029] II. Workpiece positioning and clamping:

[0030] Align the reference hole of the front subframe longitudinal beam workpiece with the cylindrical main locating pin 11, and place it stably so that the bottom surface of the workpiece is in contact with the bottom auxiliary locating block 12 and the side surface is in contact with the side auxiliary locating block 13, thus completing the six-degree-of-freedom positioning. Then, press down the upper quick clamp 4 and the side quick clamp 6 in sequence to reliably secure the workpiece.

[0031] III. Groove Inspection:

[0032] Manually rotate the axially rotating movable support arm 19 to allow the groove position detection block 14 to enter the groove to be measured on the workpiece. Visually assess whether the fit between the detection block and the groove contour is smooth and without interference. Subsequently, insert the go-no-go depth gauge 15 into the groove. The depth is deemed acceptable if the "go end" can smoothly enter the groove while the "no-go end" cannot.

[0033] IV. Profile Contour Inspection:

[0034] Use the go / no-go gauge 17 to sequentially check the standard gaps between the workpiece and the side inspection surface 8 and the bottom inspection surface 9. It is considered qualified if the "go end" can pass through and the "no-go end" cannot pass through.

[0035] Use a knife-edge go / no-go gauge 20 to check the gap between the workpiece contour and the upper edge of the side inspection surface 8 to determine whether it is within the allowable tolerance zone.

[0036] V. Component Length Inspection:

[0037] Use the go / no-go gauge 17 to check the standard gap between the end face of the workpiece and the end face detection surface 10. If the "go end" can pass through and the "no-go end" cannot pass through, then the length of the workpiece is qualified.

[0038] VI. Cross-sectional dimension inspection:

[0039] Take two H-shaped cross-section test templates 18 in sequence, and fit their "through end" perpendicular to the cross-section direction onto the workpiece. If the "through end" can be fitted smoothly, but the "stop end" cannot be fitted, then the cross-section height and width dimensions are qualified.

[0040] VII. Comprehensive Judgment and Workpiece Unloading:

[0041] The workpiece can be deemed a qualified product only if all the above-mentioned test items pass. Loosen the upper quick-release clamp 4 and the side quick-release clamp 6, remove the workpiece from the fixture, and the inspection process ends.

Claims

1. A comprehensive inspection fixture for the longitudinal beams of a front subframe of an automobile, characterized in that: The support platform consists of a rectangular platform as the main body, with four square thick steel plates welded and fixed to the bottom as support legs. Three cylindrical calibration reference columns are fixed to the support platform with countersunk screws, and four lifting columns are fixed to the support platform with screws. The lifting columns are variable diameter cylinders, with the outer diameter being the largest, the middle diameter being the smallest, and the inner diameter being in between. The inner diameter has milled surfaces on the top and bottom to facilitate bolt tightening. The inspection datum unit consists of a main locating pin, two bottom auxiliary locating blocks, and one side auxiliary locating block. The main locating pin is fixed to the bottom inspection surface by countersunk screws. The main locating pin is a square column at the bottom and a cylindrical shape at the top, with the top of the cylinder rounded. The two square bottom auxiliary locating blocks are fixed to the bottom inspection surface by countersunk screws. The square auxiliary locating block is fixed to the side inspection surface by countersunk screws. The workpiece is fixed by three top quick clamps and one side quick clamp, which is used for six-degree-of-freedom positioning and fixing of the workpiece. This datum is designed based on the key features of the workpiece's geometric dimensions and tolerance drawings. The groove detection unit is used to detect the position and depth of grooves on a workpiece; the groove position detection block is connected to the axially rotating movable support arm by screws, and the axially rotating movable support arm is hinged to the groove detection block support seat by a stainless steel shaft and two copper sleeves; the groove detection block support seat is fixed to the support foot platform by bolts; the go-no-go depth gauge detects the depth of the pit in the workpiece. The profile inspection unit is used to inspect the profile of the workpiece's side and bottom surfaces and the gap between them and the reference surface. The side and bottom inspection surfaces are rectangular thick plates connected to the support platform by screws. The bottom and side inspection surfaces are checked against the go and no-go gauges to confirm their compliance. The top surface is inspected using a tool gauge to check the profile of the upper plane. The length detection unit detects the total length of the workpiece or the position of the end face by using the end face detection surface and the go / no-go gauge. The cross-sectional dimension inspection unit uses a dedicated go / no-go template to quickly inspect the height and width of the workpiece cross-section.

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