Hammer Drill Piston Cylinder Supporting Plate Design
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing hammer drills experience unnecessary impacting motion in drill mode, which reduces the durability of the piston cylinder due to constant pressure from a coil spring used to prevent this motion.
Innovation Solution
A supporting plate with a base portion and side plates is introduced at the rear end of the piston cylinder, featuring projections and a trimmed portion, to maintain the coil spring's pressing action while preventing unnecessary impacting motion and ensuring stability and ease of installation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If a coil spring is provided to press the piston cylinder to prevent unnecessary impacting motion in drill mode, then the harmful impacting motion is prevented, but the piston cylinder durability deteriorates due to constant pressing
Solution Approach 1:
The coil spring is designed to press the piston cylinder only during specific operational phases (when impacting motion needs to be prevented), rather than continuously. The spring engages and disengages periodically based on the operational mode, eliminating constant pressure that causes wear while maintaining effectiveness in preventing harmful impacting motion during drill mode.
Solution Approach 2:
The pressing force parameter of the coil spring is dynamically adjusted based on operational requirements. During drill mode, the spring applies sufficient pressure to prevent impacting motion. During hammer mode, the pressing force is reduced or eliminated to avoid unnecessary wear on the piston cylinder, thus changing the force parameter according to operational conditions.
2Stability of the object's composition
If the coil spring constantly presses the piston cylinder to prevent impacting motion, then the drill mode stability is improved, but the piston cylinder wear increases
Solution Approach 1:
The coil spring applies pressing force periodically only when needed for drill mode stability, rather than continuously. The spring mechanism engages during drill mode to stabilize the piston cylinder and disengages during other modes, providing stability when required while minimizing wear over the long term through intermittent rather than constant contact.
Solution Approach 2:
The pressing force from the coil spring is made dynamic rather than static. The spring pressure can vary based on operational conditions, allowing high pressure for stability during drill mode while reducing pressure during hammer mode or idle states, thus adapting the force application to actual needs and reducing unnecessary wear.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively prevents unnecessary impacting motion in drill mode without diminishing the piston cylinder's durability, maintains the coil spring's pressing action, and allows for stable positioning and easy installation of the supporting plate.
Implementation Method 1
a coil spring provided rearward of the piston cylinder so as to press the piston cylinder to an advanced position
Implementation Method 2
A swash bearing is rotatably fitted on an outer peripheral surface of the boss sleeve. A connecting arm is provided on an upper surface of the swash bearing to protrude upward.
Implementation Method 3
the friction between the outer surface of the intermediate shaft and the inner surface of the boss sleeve in contact causes the boss sleeve to rotate
Data Source
Figure 1
Figure 2
Figure 3A~3C
AI summary
In a hammer drill, a coil spring 43 is disposed rearward of a piston cylinder 23 inside a housing 2 so as to press the piston cylinder 23 to an advanced position when the hammer drill operates in a drill mode, and a supporting plate 36 is disposed at a rear end of the piston cylinder 23. The supporting plate 36 includes a pair of side plates 40 and a base portion connecting front ends of the side plates 40. The base portion is in contact with a rear surface of the piston cylinder 23, and rear ends of the side plates 40 are in contact with a front end of the coil spring 43. Openings provided in the side plates 40 are configured to hold a pin 37 on which a connecting arm 34 is pivoted.