JP6501194B1 - Hammer drill bit - Google Patents

Abstract

PROBLEM TO BE SOLVED: With a conventional hammer drill bit, the structure of the blade is simple, it is easy to correct the blade after use, and there is no product which can maintain the initial performance for a long time, and a countermeasure is desired. SOLUTION: The angle of the cutting edge of a hammer drill bit is optimized, and the head of the hammer drill bit is made longer to realize a hammer drill bit capable of maintaining high performance for a long time. [Selected figure] Figure 2

Description

  The present invention relates to a tool used for concrete drilling operations.

  Although there are hammer drill bits conventionally used for various concrete drilling operations, there is no hammer drill bit that has a simple blade structure, makes it easy to correct the blade after use, and can maintain initial performance for a long time. .

Japanese Patent Application Publication No. 10-369830 Japanese Patent Application No. 2001-559638 Japanese Patent Application No. 2004-511019

  Bits for hammer drills often use cemented carbide on the head, so it is often said that correction of the blade is impossible, but there is a high-performance diamond grinding stone that can be set on small grinders in recent years. However, because it can be easily corrected, it is desirable to realize a hammer drill bit with high drilling performance with the blade correction in mind.

  In order to achieve the above object, the present invention achieves the above-mentioned object by setting the internal angle of the blade front face of the hammer drill bit (1) to 60 ° to 65 ° (7), (8) from the hammer drill bit center line (6) ), And the internal angle of the front edge of the hammer drill bit head (1) is 120 ° to 130 ° and the internal angle of the blade on the side of the hammer drill bit head (1) Hammer drill bit center line (6) from 20 ° to 25 ° (9), the other side of the blade inside angle is 30 ° to 35 ° (10) from hammer drill bit center line, hammer drill The overall inside angle of the blade on the side of the bit head (1) is 50 ° to 60 °. In addition, the hammer drill bit head (1) is 1.5 times the head diameter of the hammer drill bit and the hammer can withstand long-term use while maintaining the initial performance even if the worn cutting edge is corrected Implement a drill bit.

  As described above, the hammer drill bit of the present invention is highly usable in concrete drilling work and is easy to use because it can be easily corrected after use and can endure long-term use.

Hammer drill bit front view showing an embodiment of the present invention Side view of the same bit for hammer drill Enlarged sectional view of the head of the bit for the same hammer drill Enlarged sectional view of the head side of the bit for the same hammer drill

MODES FOR CARRYING OUT THE INVENTION

  Hereinafter, embodiments of the present invention will be described.

  In the hammer drill bit, the smaller the internal angle of the blade in front of the head, the sharper the tip of the blade, and the more stable the drilling position on concrete. However, if it is too sharp, the depth at the center of the tip of the hole may be increased, and the impact strength of the outer cone anchor may be reduced. From these facts, it is considered optimal to set the internal angle of the head face of the hammer drill bit to 120 ° to 130 °.

  In the hammer drill bit, the smaller the internal angle on the side of the head, the sharper the tip of the blade, and the higher the drilling ability to concrete. However, if it is made too sharp, the edge may be damaged if it hits hard aggregate such as rebar inside concrete during drilling. From these facts, it is considered optimal to set the internal angle of the blade on the side of the head of the hammer drill bit to 50 ° to 60 °.

  Since the hammer drill bit is used for drilling concrete, even if cemented carbide is used for the head, the cutting edge wears and the drilling ability decreases with the progress of the drilling operation, and therefore the correction of the cutting edge is required. In recent years, there are high-performance diamond wheels that can be set on small grinders, so even cemented carbide blades can be easily corrected. From the above, it is possible to endure long-term use by extending the length of the hammer drill bit head even if the number of times of blade correction is increased. The length of the hammer drill bit head is considered to be 1.5 times the head diameter.

  As described above, in order to make it possible to easily correct the cutting edge of the hammer drill bit with a diamond grindstone, the usual two-blade system is optimum, and it is extremely difficult in the three-blade delta system. There is also a method of providing a protrusion at the center of the cutting edge with a two-blade hammer drill bit to stabilize the drilling position, but it is impossible to correct the cutting edge leaving the protrusion, which is not practical.

Explanation of attached number

1 Bit head for hammer drill 2 Cemented carbide part 3 Bit body for hammer drill 4 Chip discharge groove 5 Shank 6 Bit center line for hammer drill 7 Bit angle from bit center line for hammer drill 8 Bit center line for hammer drill bit Blade angle 9 blade angle from bit center line for hammer drill 10 blade angle from bit center line for hammer drill

Claims (1)

  The internal angle of the front face of the hammer drill bit head (1) is 60 ° to 65 ° (7), (8) from the hammer drill bit center line (6), and the front face of the head (1) The total internal angle of the blade is 120 ° to 130 °, and the internal angle of the blade on the side of the hammer drill bit head (1) is 20 ° to 25 ° from the center line of the hammer drill bit (6) The inside angle of the blade on the other side is 30 ° to 35 ° (10) from the center line (6) of the bit for hammer drills, and the inside angle of the blade on the side of the head (1) is 50 ° A hammer drill bit with 60 ° and a hammer drill bit head (1) length 1.5 times the diameter of the hammer drill bit head (1).

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