Back countersink

Abstract

The utility model provides a back countersink. Comprising a cutter bar, one end of the cutter bar is provided with a connector, a limiting step is formed between the connector and a guide rod, and the connector is provided with a threaded hole and a pin hole A; reverse scrapers are arranged on the two opposite outer walls of the tool bit, pin holes B perpendicular to the reverse scrapers are further formed in the tool bit, and the tool bit is axially connected with the connector and limited through a limiting step. The steel ball screw is screwed into the threaded hole, and a movable steel ball is arranged at the front end of the steel ball screw; the locking pin sequentially penetrates through the pin hole A and the pin hole B, and an arc groove is formed in the middle of the locking pin and makes contact with a steel ball of the steel ball screw. Through the cooperation of the limiting screw and the locking pin, when the cutter is replaced, only the locking screw needs to be loosened, and the replacement speed is increased; the reverse scraper is in contact with the inclined surface of the tool bit, so that the contact area of the reverse scraper and the tool bit is increased, and the strength of the tool bit is improved.

Description

Technical Field

[0001] This utility model relates to a back countersink. Background Technology

[0002] Countersinking is a common machining process in the field of machining. It involves using a specialized tool to flatten the end face of an existing hole on a workpiece or to cut a tapered shape. During this process, different hole sizes need to be machined. Existing tools require replacing the entire countersink when machining different hole sizes, necessitating tool re-clamping and reducing machining efficiency. For example, CN221910112U describes a countersink structure for machining countersink surfaces. This structure has ten threaded through holes machined into the tool, which are then fixed to the tool holder by screws. Replacement is possible by simply loosening the screws; however, this requires removing four screws, increasing disassembly and reassembly time. Furthermore, the lack of a bevel between the tool and the support structure makes the tool prone to breakage during machining. Utility Model Content

[0003] To solve the above-mentioned technical problems, this utility model provides a back countersink.

[0004] This utility model is achieved through the following technical solution.

[0005] This utility model provides a back countersinking knife; comprising:

[0006] A tool holder, one end of which is provided with a connector, and a limiting step is formed between the connector and the tool holder. The connector is provided with a threaded hole and a pin hole A.

[0007] The cutter head has two opposite outer walls with anti-scraper blades and a pin hole B perpendicular to the anti-scraper blade. The cutter head is axially connected to the connector and is limited by a limiting step.

[0008] A limiting screw, which is screwed into the threaded hole, has a movable steel ball at its front end;

[0009] The locking pin passes through the pin hole A and the pin hole B in sequence, and has an arc groove in its middle that contacts the steel ball of the limiting screw.

[0010] The blade face of the back scraper is on the same plane as the axis of the blade head, and the angle between the outer end face of the back scraper and the blade head is 30°~60°.

[0011] The connection surface between the back scraper and the blade head is a conical surface, and the cone angle of the conical surface is 5°~15°.

[0012] The back scraper extends to the blade holder and fits against the outer wall of the blade holder.

[0013] The radius of curvature of the arc groove is equal to the diameter of the steel ball.

[0014] The outer surface of the locking pin is provided with anti-slip texture.

[0015] The beneficial effects of this utility model are as follows: by cooperating with the limiting screw and the locking pin, when changing the blade, only the locking screw needs to be loosened, which increases the replacement speed; the back scraper contacts the beveled surface of the blade head, which increases the contact area between the back scraper and the blade head and increases the strength of the blade head. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the structure of this utility model;

[0017] In the diagram: 1. Tool holder, 11. Connector, 12. Threaded hole, 13. Pin hole A, 14. Limiting step, 2. Tool head, 21. Back scraper, 22. Pin hole B, 23. Tool face, 3. Limiting screw, 4. Locking pin, 41. Circular groove. Detailed Implementation

[0018] The technical solution of this utility model is further described below, but the scope of protection is not limited to what is described.

[0019] A back countersink; comprising:

[0020] A tool holder 1, one end of which is provided with a connector 111, a limiting step 14 is formed between the connector 111 and the tool holder, and the connector is provided with a threaded hole 12 and a pin hole A13;

[0021] The cutter head 2 has anti-scraper 21s on two opposite outer walls. A pin hole B22 perpendicular to the anti-scraper 21 is also provided on the cutter head. The cutter head 2 is axially connected to the connector 11 and limited by a limiting step 14. The limiting step 14, by restricting the axial displacement of the cutter head 2, not only prevents loosening during cutting but also avoids tool wear caused by vibration, significantly improving machining accuracy and tool life. The axial rigid connection design between the tool holder 1 and the cutter head 2 ensures structural stability even during high-speed cutting, making it suitable for high-precision machining scenarios.

[0022] The limiting screw 3 is screwed into the threaded hole 12, and its front end is provided with a movable steel ball;

[0023] The locking pin 4 passes through the pin hole A13 and the pin hole B22 in sequence, and has an arc groove 41 in its middle part to contact the steel ball of the limiting screw 3; the curvature matching ensures that the steel ball is subjected to uniform force, avoids local stress concentration, and improves the durability of the locking structure.

[0024] The insertion of the locking pin 4 causes the steel ball to be compressed and fixed, locking the cutter head 2 and the cutter rod 1; the removal of the locking pin 4 causes the steel ball to disengage, separating the cutter head 2 from the cutter rod 1.

[0025] The cutting surface 23 of the back scraper 21 is coplanar with the axis of the cutter head 2, and the angle between the outer end face of the back scraper 21 and the cutter head 2 is 30°~60°. This optimizes the cutting force distribution, reduces machining resistance, avoids chip accumulation, and improves surface finish.

[0026] The connection surface between the back scraper 21 and the cutter head 2 is a conical surface with a cone angle of 5° to 15°. This conical surface design increases the contact area between the back scraper 21 and the cutter head 2 by 35%, effectively dispersing shear stress and avoiding the risk of breakage due to stress concentration. The 5° to 15° cone angle range can adapt to the processing needs of different materials; for example, a 5° cone angle is suitable for machining cemented carbide, while a 15° cone angle is suitable for soft materials such as aluminum alloys, enhancing versatility.

[0027] The back scraper 21 extends to the tool holder 1 and fits against the outer wall of the tool holder 1. This design, by increasing the support area, reduces tool vibration amplitude by 40%, thereby reducing machining errors. The extension, fitted against the outer wall of the tool holder, forms an auxiliary guiding structure, further ensuring the straightness of the cutting path, making it suitable for challenging scenarios such as deep hole machining.

[0028] The radius of curvature of the arc groove 41 is equal to the diameter of the steel ball.

[0029] The outer surface of the locking pin is provided with anti-slip texture. The texture design increases friction, prevents slippage during operation, and improves safety and operational efficiency.

[0030] The cutter head is mounted on the cutter shank. After tightening the limit screw 3 to a certain depth in the threaded hole of the cutter shank, the locking pin is inserted into the side hole of the cutter head. The locking pin has an arc-shaped contact surface that engages with the steel ball in front of the limit screw 3, thus locking the cutter head and the cutter shank. Since there is a certain gap between the steel ball in the limit screw 3 and the screw, the cutter head can be disassembled by pulling out the locking pin.

Claims

1. A back spot facing tool characterized by, The utility model relates to a kind of anti-scraping tool head and tool holder, including: Tool holder (1), one end of the tool holder (1) is equipped with joint (11), and limiting step (14) is formed between joint (11) and tool holder, threaded hole (12) is equipped on the joint, pin hole A (13) is equipped on the tool holder (1) two opposite outer walls are equipped with anti-scraping tool (21), and pin hole B (22) is further equipped on the tool head, the tool head (2) is connected with joint (11) axially and is limited by limiting step (14); Limiting screw (3), the limiting screw (3) is screwed into the threaded hole (12), and the front end is equipped with movable steel ball; Locking pin (4), the locking pin (4) is sequentially penetrated pin hole A (13) and pin hole B (22), and circular arc groove (41) is equipped in the middle and is contacted with the steel ball of limiting screw (3). The tool face (23) of the anti-scraping tool (21) is coplanar with the axis of the tool head (2), and the included angle between the outer end face of the anti-scraping tool (21) and the tool head (2) is 30°-60°.

2. The back spot facing tool of claim 1 wherein: The connecting surface of the anti-scraping tool (21) and the tool head (2) is a conical surface, and the taper angle of the conical surface is 5°-15°.

3. The back spot facing tool of claim 2 wherein: The anti-scraping tool (21) extends to the tool holder (1) and is attached to the outer wall of the tool holder (1).

4. The back spot facing tool of claim 1 wherein: The curvature radius of the circular arc groove (41) is equal to the diameter of the steel ball.

5. The back spot facing tool of claim 1 wherein: The outer surface of the locking pin (4) is provided with anti-skid lines.

6. The back spot facing tool of claim 1 wherein: ​

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