Hydraulic Hammer Threaded Fitting Alignment via Gauge Measurement
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Hydraulic hammers face challenges in maintaining accurate rotational alignment and resisting tensile stresses due to the use of tie rods or clips, which can fail under leverage, and the difficulty in machining threaded fittings that remain aligned after heat treatment.
Innovation Solution
A method using male and female gauges with cooperatively formed threaded fittings, where the gauges are marked to determine relative rotational positions before and after hardening, allowing for precise machining adjustments to maintain alignment and secure the chuck housing and body together.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If threaded fittings are machined in the chuck housing and body, then the connection can resist tensile stresses and eliminate tie rods, but accurate rotational alignment becomes difficult due to heat treatment distortion
Solution Approach 1:
The patent applies preliminary action by machining the threaded fittings in the chuck housing before heat treatment, when the material is still in its original state and easier to machine. The fittings are prepared in advance, then the heat treatment is performed, and finally alignment adjustments are made to compensate for the expected distortion. This sequence allows the threaded fittings to be established before the distorting heat treatment occurs.
Solution Approach 2:
The patent utilizes parameter changes by intentionally designing for the dimensional changes that occur during heat treatment. The threaded fittings are machined with specific parameters (dimensions, thread pitch, orientation) that account for the anticipated distortion. After heat treatment, the actual parameters are measured and adjusted to achieve the required rotational alignment, effectively compensating for the parameter changes caused by heat treatment.
2Ease of manufacture
If tie rods or clips are used to hold the chuck housing and body together, then assembly is simple, but the connection fails under leverage stresses from embedded tool pieces
Solution Approach 1:
The patent applies the taking out principle by removing the tie rods and clips from the hydraulic hammer design. Instead of using these separate fastening components, the invention integrates the connection function directly into the chuck housing and body through machined threaded fittings. This extraction eliminates the intermediate fastening elements that were prone to failure under leverage stresses.
Solution Approach 2:
The patent applies merging by combining the functions of the chuck housing, body, and fastening mechanism into an integrated assembly. The threaded fittings are machined directly into these components, merging the structural elements with the fastening function. This eliminates the need for separate tie rods or clips, creating a unified load-bearing structure that resists tensile stresses more effectively.
3Strength
If the chuck housing is heat treated after machining threaded fittings, then the housing gains required hardness, but significant distortion and misalignment occur
Solution Approach 1:
The patent applies preliminary action by performing the threading operation before heat treatment, when the chuck housing material is in its pre-hardened state. This allows the threaded fittings to be machined into the housing before the heat treatment process that would cause distortion. The preliminary machining ensures the fittings are established before the dimensional changes occur during hardening.
Solution Approach 2:
The patent applies feedback by measuring the actual alignment of the threaded fittings after heat treatment and using this information to make corrective adjustments. The distortion that occurs during heat treatment is measured, and this feedback is used to adjust the positioning or re-machining of the fittings to achieve the required rotational alignment. This closed-loop approach compensates for the heat treatment distortion.
Data Source
AI summary
A method of manufacturing a hydraulic hammer using a male gauge and a female gauge is provided wherein the hammer comprises a body and a chuck housing that are connectable by cooperatively formed thread fittings. A cooperatively threaded male gauge and female gauge can be used to form the threads on the body and the chuck housing and to determine the rotational orientation of the body and the chuck housing relative to one another. One of the gauges can be used to measure distortion of the chuck housing caused by heat treatment subsequent to the formation of the thread fitting and thereby to determine the required subsequent machining of the chuck housing necessary to retain the appropriate relative rotational orientation when the chuck housing is connected to the body. The method can comprise the steps of making and appropriately marking the male gauge and the female gauge.