A comprehensive testing fixture for brake base six convex platform

Abstract

The utility model relates to a kind of comprehensive testing fixture of six boss of brake bottom plate, belong to the measurement technical field of drum brake bottom plate, including base, the base is equipped with digital dial gauge, the digital dial gauge below is equipped with limit tooling between base, the limit tooling is equipped with measured part between digital dial gauge, the measured part is equipped with several boss with digital dial gauge movable contact. The limit tooling includes positioning plate, the positioning plate is equipped with bottom plate between base, the positioning plate is equipped with the center shaft that passes through base and is fixed with bottom plate. For the special measuring equipment of the fast, accurate detection six boss end surface position degree on brake bottom plate. By using the positioning principle of '' one side two pins '' and high-precision digital dial gauge. Rapid clamping, rotary measurement to measured part can be realized, effectively ensure the accuracy and consistency of detection result, applicable to batch inspection on production line.

Description

Technical Field

[0001] This utility model relates to the field of drum brake base plate measurement technology, specifically to a comprehensive inspection tool for a brake base plate with six protrusions. Background Technology

[0002] The brake backing plate is the load-bearing component of a drum brake. It has six stamped platforms for mounting the brake shoes, thus requiring strict control over the height and process stability of these six bosses. The term "six bosses" typically refers to the mounting holes or locating surfaces on the brake backing plate used to precisely fix it to the axle (steering knuckle or wheel hub). These six bosses (or the holes on them) are the "lifeline" connecting the entire braking system to the vehicle's suspension system. The precision of these six bosses directly determines the performance and safety of the entire braking system. Therefore, measuring them is of paramount importance in quality control.

[0003] The current measurement method uses a coordinate measuring machine (CMM), which collects a large number of coordinate points on the surface of the boss and inside the hole using a probe, and then calculates precise data such as position, flatness, and hole diameter using software. However, due to the vibrations present in the stamping process, it is impossible to install a CMM on the stamping line, and each CMM measurement takes 5 minutes. This measurement method cannot meet the needs of rapid on-site assessment during mass production.

[0004] The main manufacturing process for the brake backplate is stamping. The inherent characteristics of this process present challenges that must be controlled through measurement.

[0005] (1) Material springback: After the steel plate is stamped, it will elastically recover, resulting in deviations between the position, angle and flatness of the boss and the mold design value.

[0006] (2) Mold wear: Long-term production will lead to mold wear, especially the wear of locating pins and forming surfaces, which will directly affect the consistency of boss size and position.

[0007] (3) Uneven material thickness: Small differences in the thickness of the steel plate will be amplified after stamping, affecting the height of the boss and the forming quality.

[0008] (4) Stamping stress: The internal stress generated during the stamping process may cause slight warping deformation of the parts, affecting the flatness of the plane where the boss is located.

[0009] If the precision of the six bosses is not up to standard, it will cause a series of serious quality problems:

[0010] Positional accuracy is out of tolerance:

[0011] Failure mode: The brake backing plate cannot be successfully installed onto the axle, or it generates huge internal stress after installation.

[0012] Consequences: brake vibration, abnormal noise, fatigue fracture of parts, and even brake failure in extreme cases.

[0013] Flatness out of tolerance:

[0014] Failure mode: The mounting surface formed by the six bosses is not an ideal plane.

[0015] Consequences: Gaps exist at the mating surface with the axle, and the connecting bolts experience uneven stress, which can lead to loosening over time. Simultaneously, it can cause deformation of the brake backing plate, resulting in poor contact between the brake shoes and the brake drum, causing uneven wear, brake noise, and reduced braking force.

[0016] Hole diameter / hole spacing out of tolerance:

[0017] Failure mode: The connecting bolt cannot pass through or the fit is too loose / too tight.

[0018] Consequences: Difficult installation, reduced connection reliability, and increased vibration.

[0019] Therefore, in order to ensure the safety, stability and durability of the braking system, the key geometric dimensions and tolerances of the six bosses must be strictly controlled. Summary of the Invention

[0020] This invention addresses the shortcomings of existing technologies by providing a comprehensive inspection tool for a brake base plate with six bosses. This tool is a dedicated measuring device for quickly and accurately detecting the positional accuracy of the end faces of the six bosses on the brake base plate. Utilizing a "one-face, two-pin" positioning principle and a high-precision digital dial indicator, it enables rapid clamping and rotational measurement of the tested parts, effectively ensuring the accuracy and consistency of the test results. It is suitable for batch inspection on production lines.

[0021] The above-mentioned technical problems of this utility model are mainly solved by the following technical solutions:

[0022] A comprehensive inspection fixture for a brake base plate with six bosses includes a base, on which a digital dial indicator is mounted. A limiting fixture is located between the digital dial indicator and the base. A part to be measured is located between the limiting fixture and the digital dial indicator. The part to be measured has several bosses that movably contact the digital dial indicator. The limiting fixture includes a positioning plate, and a base plate is located between the positioning plate and the base. A central shaft is provided on the positioning plate, penetrating the base and fixed to the base plate.

[0023] Preferably, the bottom plate is provided with an anti-rotation pin mounting seat on its side, and the anti-rotation pin mounting seat is provided with an anti-rotation pin that is movably inserted into the bottom plate in a slot-like manner.

[0024] Preferably, the positioning plate is provided with a main positioning pin and a secondary positioning pin for positioning the part to be measured and for inserting into the positioning plate.

[0025] Preferably, a support column is provided between the digital dial indicator and the base, and a mounting bracket is provided between the support column and the digital dial indicator for rotational connection around the support column.

[0026] Preferably, the side of the support column is used as a reference position block for calibrating the reference value of the digital dial indicator.

[0027] Preferably, the base is provided with handles on both the front and rear sides of the upper end, which are screwed together and fixed to the base.

[0028] This invention can achieve the following effects:

[0029] This invention provides a comprehensive inspection fixture for six bosses on a brake base plate. Compared with existing technologies, it is a dedicated measuring device for quickly and accurately detecting the positional accuracy of the end faces of the six bosses on the brake base plate. By employing a "one-face, two-pin" positioning principle and a high-precision digital dial indicator, it enables rapid clamping and rotational measurement of the measured part, effectively ensuring the accuracy and consistency of the inspection results. It is suitable for batch inspection on production lines.

[0030] High efficiency: The measurement of six feature points can be completed in one clamping, without the need for repeated positioning.

[0031] High precision: The "one-face, two-pin" positioning and comparative measurement method effectively reduces human error and systematic error.

[0032] Easy to operate: The process is clear, the skill requirements for operators are not high, and it is easy to learn.

[0033] Intuitive data: The digital dial indicator provides clear readings and allows for direct determination of deviation values, facilitating the assessment of compliance.

[0034] Structural stability: The anti-rotation pin design ensures stability in non-measuring conditions and protects precision components. Attached Figure Description

[0035] Figure 1 This is a schematic diagram of the integrated inspection tool and brake base plate inspection structure of this utility model.

[0036] Figure 2 This is a schematic diagram of the structure of the part being tested in this utility model.

[0037] Figure 3 This is a schematic diagram of the integrated inspection fixture in this utility model.

[0038] In the diagram: 1. Base; 2. Support column; 3. Mounting bracket; 4. Digital dial indicator; 5. Measured part; 6. Limiting fixture; 7. Reference block; 8. Boss; 9. Main positioning pin; 10. Secondary positioning pin; 11. Handle; 12. Central shaft; 13. Positioning plate; 14. Anti-rotation pin; 15. Anti-rotation pin mounting seat; 16. Base plate. Detailed Implementation

[0039] The technical solution of this utility model will be further described in detail below through embodiments and in conjunction with the accompanying drawings.

[0040] Example: Figure 1 , Figure 2 and Figure 3 As shown, a comprehensive inspection fixture for a brake base plate with six bosses includes a base 1. Handles 11, screwed and fixed to the base 1, are provided on both the front and rear sides of the upper end of the base 1. A digital dial indicator 4 is mounted on the base 1. A support column 2 is provided between the digital dial indicator 4 and the base 1. A mounting bracket 3, rotatably connected around the support column 2, is provided between the support column 2 and the digital dial indicator 4. A reference gauge block 7 is located on the side of the support column 2 for calibrating the reference value of the digital dial indicator 4. A limiting fixture 6 is provided below the digital dial indicator 4 and between it and the base 1. A part to be measured 5 is provided between the limiting fixture 6 and the digital dial indicator 4. The part to be measured 5 has six bosses 8 that movably contact the digital dial indicator 4. The limiting fixture 6 includes a positioning plate 13. The positioning plate 13 has a main positioning pin 9 and a secondary positioning pin 10 for positioning the part to be measured 5 and inserting into the positioning plate 13. A base plate 16 is provided between the positioning plate 13 and the base 1. A central shaft 12 is provided on the positioning plate 13, which passes through the base 1 and is fixed to the base plate 16. An anti-rotation pin mounting seat 15 is provided on the side of the base plate 16. An anti-rotation pin 14 is provided on the anti-rotation pin mounting seat 15, which is movably inserted into the base plate 16 in a slot.

[0041] Before measurement, zero the bottom probe of the digital dial indicator 4 on the reference gauge block 7. Then, with the positioning surface of the part to be measured 5 facing down, ensure it is in full contact with the positioning plate 13, and insert the main positioning pin 9 and the auxiliary positioning pin 10 into the corresponding positioning holes. Rotate the mounting bracket 3 to move the bottom probe of the digital dial indicator 4 into the part to be measured 5. Pull out the anti-rotation pin 14, rotate the part to be measured 5, so that the bottom probe of the digital dial indicator 4 contacts the end faces of the six bosses 8 of the part to be measured 5 respectively, and record the measurement readings.

[0042] The working principle is relative comparison measurement.

[0043] Establish a reference: Using the known precise height of the reference gauge block 7, set the reading of the digital dial indicator 4 to "0". This "0" point represents the ideal position or theoretically correct dimension of the boss end face.

[0044] Precise positioning: By using the "one-sided two-pin" method (positioning plate 13 + main / secondary positioning pins), the part to be measured 5 is completely fixed on the fixture, eliminating measurement errors caused by different clamping positions.

[0045] Rotational measurement: The part being measured (5) along with the entire limiting fixture (6) is precisely rotated around the central axis (12). Each rotation of a specific angle (usually 60°) will rotate the next boss (8) directly below the digital dial indicator (4).

[0046] Data reading: The probe of the digital dial indicator 4) contacts the end face of the six bosses in sequence, and the displayed reading is the deviation (positive or negative) of the end face of the boss relative to the reference block (ideal position).

[0047] Step 1: Calibration and Zeroing

[0048] Ensure the gauge is placed on a stable surface.

[0049] Rotate the mounting bracket 3 so that the probe of the digital dial indicator 4 is moved directly above the reference gauge block 7.

[0050] Slowly lower the dial indicator probe until it gently contacts the upper surface of the gauge block.

[0051] Press the "ZERO" or "Zero" button on the digital dial indicator to set the current reading to 0.00 mm.

[0052] Rotate the mounting bracket upwards to move the probe away from the gauge block.

[0053] Step 2: Install the part to be tested

[0054] Place the part to be tested 5 with its positioning surface facing down on the positioning plate 13, ensuring full contact between the two.

[0055] Insert the main locating pin 9 and the secondary locating pin 10 into the corresponding locating holes of the part being measured to complete the precise positioning of the part.

[0056] Step 3: Measurement

[0057] Rotate the mounting bracket 3 to move the probe of the digital dial indicator 4 to the measurement starting position inside the part being measured 5 (usually near the first boss).

[0058] Pull out the anti-rotation pin 14 from the anti-rotation pin mounting seat 15 to release the locking of the limit fixture.

[0059] Gently rotate the part 5 to be measured by hand until the end face of its first boss 8 is directly below the dial indicator probe.

[0060] Slowly lower the dial indicator probe until it contacts the end face of the boss. After the reading stabilizes, record the value.

[0061] Continue to rotate the part being measured smoothly, and then rotate the remaining five bosses under the probe in turn. Repeat the measurement and record all readings.

[0062] Step 4: Complete the measurement

[0063] After the measurement is completed, insert the anti-rotation pin 14 back into the slot of the base plate 16 to lock the fixture.

[0064] Rotate the mounting bracket and remove the dial indicator.

[0065] Remove the main and secondary locating pins, and then remove the part being tested.

[0066] In summary, this comprehensive inspection fixture for the six bosses on the brake base plate is a specialized measuring device used for the rapid and accurate detection of the positional accuracy of the end faces of the six bosses on the brake base plate. By employing a "one-face, two-pin" positioning principle and a high-precision digital dial indicator, it enables rapid clamping and rotational measurement of the measured parts, effectively ensuring the accuracy and consistency of the inspection results, and is suitable for batch inspection on production lines.

[0067] It will be apparent to those skilled in the art that this invention is not limited to the details of the above exemplary embodiments, and that it can be implemented in other specific forms without departing from the essential characteristics of the invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

[0068] In summary, the above description is only a specific embodiment of the present utility model, but the structural features of the present utility model are not limited thereto. Any changes or modifications made by those skilled in the art within the scope of the present utility model are covered by the patent scope of the present utility model.

Claims

1. A comprehensive inspection fixture for a brake base plate with six protrusions, characterized in that: The device includes a base (1), on which a digital dial indicator (4) is provided. A limiting fixture (6) is provided between the digital dial indicator (4) and the base (1). A part to be measured (5) is provided between the limiting fixture (6) and the digital dial indicator (4). The part to be measured (5) is provided with several bosses (8) that are movably in contact with the digital dial indicator (4). The limiting fixture (6) includes a positioning plate (13). A base plate (16) is provided between the positioning plate (13) and the base (1). A central shaft (12) is provided on the positioning plate (13) that penetrates the base (1) and is fixed to the base plate (16).

2. The comprehensive inspection fixture for a brake base plate with six bosses according to claim 1, characterized in that: The base plate (16) is provided with a rotation-resistant pin mounting seat (15) on its side, and the rotation-resistant pin mounting seat (15) is provided with a rotation-resistant pin (14) that is movably inserted into the base plate (16) in a slot.

3. The comprehensive inspection fixture for a brake base plate with six bosses according to claim 1, characterized in that: The positioning plate (13) is provided with a main positioning pin (9) and a secondary positioning pin (10) for positioning the part to be measured (5) and for inserting into the positioning plate (13).

4. The comprehensive inspection fixture for a brake base plate with six bosses according to claim 1, characterized in that: A support column (2) is provided between the digital dial indicator (4) and the base (1), and a mounting bracket (3) is provided between the support column (2) and the digital dial indicator (4) for rotational connection around the support column (2).

5. A comprehensive inspection fixture for a brake base plate with six bosses according to claim 4, characterized in that: The support (2) side is used as a reference position block (7) for calibrating the reference value of the digital dial indicator (4).

6. A comprehensive inspection fixture for a brake base plate with six bosses according to claim 1, characterized in that: The base (1) is provided with handles (11) on both the front and rear sides of the upper end, which are screwed and fixed to the base (1).

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