Hole opener

Abstract

The utility model relates to the field of tappers, in particular to a tapper which comprises a circular saw cover body used for tapping, a positioning drill body is arranged on the circular saw cover body, a positioning drill bit is brazed on the positioning drill body, and the positioning drill bit is used for drilling into a contact surface before the circular saw cover body so as to position the circular saw cover body. The positioning drill has the effect of prolonging the service life of the positioning drill.

Description

Technical Field

[0001] The present application relates to the field of hole openers, and in particular to a hole opener. Background Art

[0002] A hole opener is a special circular saw mainly used for cutting circular holes. However, if a circular hole is cut directly and forced, the rotating circular saw is prone to position displacement under the action of the rotating force. Therefore, a positioning drill is often installed on the rotating center axis of the circular saw. The end of the positioning drill is pointed and contacts the cutting surface before the circular saw. The position of the circular saw is positioned by the positioning drill.

[0003] Therefore, the sharpness of the positioning drill tip is particularly important. However, during long-term use, the tip of the positioning drill is easily worn flat, making it difficult for the tip of the positioning drill to drill into the cutting surface, resulting in loss of positioning function. If the positioning drill is made of high-hardness material, the cost will be greatly increased. Utility Model Content

[0004] In order to improve the problem that the tip of the positioning drill is easily worn flat, the present application provides a hole opener.

[0005] The present application provides a hole opener, which adopts the following technical solution:

[0006] A hole opener comprises a circular saw cover for opening a hole, wherein a positioning drill body is provided on the circular saw cover, a positioning drill bit is brazed on the positioning drill body, and the positioning drill bit is used to drill into a contact surface before the circular saw cover to position the circular saw cover.

[0007] By adopting the above technical solution, if the positioning drill is made of a high-hardness and non-wear-resistant material as a whole, the cost will be greatly increased. However, the positioning drill bit and the positioning drill rod are manufactured separately, and only the positioning drill bit is made of a small amount of expensive material, while the positioning drill rod, which is the bulk of the consumables, is still made of low-priced materials. This slightly increases the cost, but greatly enhances the strength of the positioning drill and extends its service life.

[0008] Optionally, at least three drilling surfaces are formed on the end of the positioning drill bit, and a plurality of the drilling surfaces intersect to form a tip.

[0009] By adopting the above technical solution, a sharper tip is formed by multiple drill surfaces, thereby improving the positioning effect.

[0010] Optionally, a mounting rod is provided on the circular saw cover, a mounting hole groove for inserting the positioning drill body is opened on the inner wall of the circular saw cover, a tightening hole is opened on the outer wall of the mounting rod, the tightening hole is connected to the mounting hole groove, a tightening piece is inserted into the tightening hole, and the tightening piece is used to tighten on the positioning drill body.

[0011] By adopting the above technical solution, the installation and removal of the positioning drill body in the installation hole groove are controlled by the tightening member, which is convenient and fast, and facilitates the replacement and maintenance of the positioning drill body.

[0012] Optionally, thread grooves are provided on the inner wall of the fastening hole and the fastening member, and the fastening member is threadedly connected to the fastening hole through the thread grooves.

[0013] By adopting the above technical solution, a threaded connection is achieved between the fastening piece and the fastening hole through the thread groove, which facilitates the screwing in and out of the fastening piece. The self-locking performance of the thread also reduces the probability of the fastening piece retreating and improves the stability of the fastening piece.

[0014] Optionally, a pressing surface is provided on the positioning drill body, and the pressing surface is tightly fitted against the end of the pressing member.

[0015] By adopting the above technical solution, the pressing surface is used for the pressing member to fit and press against, thereby increasing the contact area between the pressing member and the positioning drill body, making the pressing of the positioning drill body more stable, and reducing the pressure, thereby protecting the positioning drill body.

[0016] Optionally, an extension sleeve is provided on the circular saw cover, and the extension sleeve is arranged outside the mounting rod, and the extension sleeve surrounds the mounting hole groove inside.

[0017] By adopting the above technical solution, the diameter of the mounting rod is increased by the extension sleeve, the impact of the mounting hole groove in the mounting rod on the structural strength of the mounting rod is reduced, and the structural strength of the mounting rod is improved.

[0018] Optionally, a drill groove for inserting the positioning drill bit is provided on the end of the positioning drill body, a limiting groove is provided on the inner wall of the drill groove, and the positioning drill bit is provided with a limiting block for inserting and sliding in the limiting groove.

[0019] By adopting the above technical solution, the positioning drill bit is limited by the limiting block and the limiting groove, which reduces the probability of the positioning drill bit sliding in the drill groove during brazing, resulting in the positioning drill bit being off the rotation axis of the circular saw cover, thereby improving the yield rate.

[0020] Optionally, the number of the limiting grooves and the limiting blocks are at least two, a plurality of the limiting grooves are distributed on the inner wall of the drilling groove, and a plurality of the limiting blocks are distributed on the outer wall of the positioning drill bit.

[0021] By adopting the above technical solution, the stability of the positioning drill bit is further improved.

[0022] Optionally, a guiding bevel is provided on the end of the positioning drill bit inserted into the drill groove, and a brazing cavity for clamping the brazing material is formed between the guiding bevel and the bottom wall of the drill groove. The guiding bevel guides the brazing material on the bottom wall of the drill groove into the brazing cavity to clamp the brazing material.

[0023] By adopting the above technical solution, after the brazing material is placed into the drill groove, the positioning drill bit is inserted into the drill groove. If the brazing material is not placed at the specified position, as the positioning drill bit penetrates into the drill groove, the guiding bevel will contact the brazing material, and then the positioning drill bit continues to slide deeper, and the guiding bevel will push the brazing material to slide to the specified position. Then, during brazing, the melt is filled between the positioning drill bit and the inner wall of the drill groove through the capillary effect, making the installation of the positioning drill bit smoother and guiding the brazing material.

[0024] Optionally, there are two guiding bevels, the two guiding bevels are connected, a circular chamfer is provided at the position where the two guiding bevels are connected, and the circular chamfer is also provided between the guiding bevel and the side wall of the positioning drill bit.

[0025] By adopting the above technical solution, the installation of the positioning drill bit is further made smoother.

[0026] In summary, this application includes at least one of the following beneficial technical effects:

[0027] 1. It slightly increases the cost, but greatly enhances the strength of the positioning drill and extends its service life.

[0028] 2. Improve the yield rate of positioning drill bits and positioning drill rods. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram of the overall structure of a hole opener in Example 1 of the present application.

[0030] Figure 2 It is a schematic diagram of the exploded structure highlighting the mounting hole slots.

[0031] Figure 3 It is a schematic diagram of the explosion structure highlighting the tightening hole.

[0032] Figure 4 This is a schematic diagram of the explosion structure of a hole opener in Example 2 of the present application.

[0033] Figure 5 It is a structural diagram highlighting the guide slope.

[0034] Figure 6 It is a structural schematic diagram highlighting the guiding slope in Example 3 of the present application.

[0035] Figure 7It is a structural schematic diagram highlighting the guiding slope in Example 4 of the present application.

[0036] Explanation of the accompanying reference numerals: 1. Circular saw cover; 11. Mounting rod; 12. Mounting hole groove; 13. Tightening hole; 14. Tightening member; 15. Threaded groove; 16. Tightening surface; 17. Extension sleeve; 2. Positioning drill body; 21. Positioning drill bit; 22. Drill surface; 23. Tip; 3. Drill groove; 31. Limiting groove; 32. Limiting block; 33. Guide slope; 34. Brazing cavity; 35. Arc chamfer. DETAILED DESCRIPTION

[0037] The following is combined with Figure 1-7 This application is described in further detail.

[0038] Example 1 of the present application discloses a hole opener. Figure 1 and Figure 2 The hole saw includes a circular saw housing 1 for drilling holes. The circular saw housing 1 is a hollow cylinder with an opening. The sidewalls around the opening serve as the location for mounting a high-strength material, such as diamond, for rotary cutting and drilling. A positioning drill 2 is mounted on the inner wall of the circular saw housing 1, facing the opening. A positioning drill bit 21 is brazed and fixed to the end of the positioning drill 2 extending from the opening of the circular saw housing 1. The positioning drill bit 21 is located outside the circular saw housing 1 and penetrates the contact surface before the circular saw housing 1 to position the circular saw housing 1. The positioning drill bit 21 can be made of a high-hardness, wear-resistant material, such as cemented carbide or cobalt-containing high-speed steel.

[0039] Reference Figure 2 Four drilling surfaces 22 are formed on the end of the positioning drill bit 21 away from the positioning drill body 2. The four drilling surfaces 22 intersect with each other and converge at the same point to form a tip 23. The tip 23 is located at the position where the positioning drill bit 21 is farthest from the outside of the circular saw cover 1, and the direction of the tip 23 is the same as the direction of punching the circular saw cover 1. The extension direction of the positioning drill body 2 is coaxial with the rotation center axis of the circular saw cover 1, and the tip 23 is located on the rotation center axis of the circular saw cover 1.

[0040] Reference Figure 1 and Figure 2A mounting rod 11 is fixedly connected to the outer wall of the circular saw cover 1. The mounting rod 11 extends coaxially with the central axis of rotation of the circular saw cover 1 and is used for connecting and installing a drilling rig. A mounting hole 12 is defined on the bottom wall of the circular saw cover 1, which faces the opening. The mounting hole 12 extends coaxially with the mounting rod 11 and extends from the bottom wall of the circular saw cover 1 to the interior of the mounting rod 11. The mounting hole 12 is used to insert the positioning drill 2. An extension sleeve 17 is fixedly connected to the outer side wall of the circular saw cover 1. The extension sleeve 17 is sleeved on the outside of the mounting rod 11, and the extension sleeve 17 is located at the connection between the mounting rod 11 and the circular saw cover 1. The extension sleeve 17 is fixedly connected to the mounting rod 11 so that the extension sleeve 17 surrounds the mounting hole groove 12 in the mounting rod 11. The extension length of the extension sleeve 17 is adapted to the depth of the mounting hole groove 12 in the mounting rod 11. The extension sleeve 17 is equivalent to increasing the thickness of the mounting rod 11 in disguise.

[0041] Reference Figure 2 and Figure 3 A tightening hole 13 is formed on the outer wall of the extension sleeve 17. The tightening hole 13 extends toward the center axis of the mounting rod 11. The tightening hole 13 penetrates the side wall of the extension sleeve 17 and the side wall of the mounting rod 11 and is connected to the mounting hole groove 12. A tightening member 14 is inserted into the tightening hole 13. A threaded groove 15 is formed on the inner wall of the tightening hole 13 and the tightening member 14. The tightening member 14 is threadedly connected to the tightening hole 13 through the threaded groove 15. The tightening member 14 can be a hexagonal bolt. A tightening surface 16 is formed on the outer wall of the positioning drill body 2 inserted into the mounting hole groove 12. The angle of the tightening surface 16 matches the angle of the end of the tightening member 14 that penetrates into the mounting hole groove 12. The end of the tightening member 14 that penetrates into the mounting hole groove 12 presses against the tightening surface 16 of the positioning drill body 2.

[0042] The implementation principle of a hole opener in embodiment 1 of the present application is: during production, the positioning drill bit 21 is first inserted into the positioning drill body 2, and then the positioning drill bit 21 is fixed to the positioning drill body 2 through a brazing process, and then the positioning drill body 2 is inserted into the mounting hole groove 12, and the positioning drill body 2 is rotated so that the tightening surface 16 faces the opening of the tightening hole 13, and then the tightening member 14 is screwed into the mounting hole groove 12 so that the tightening member 14 is tightened on the tightening surface 16.

[0043] Example 2:

[0044] The difference from Example 1 is that Figure 4A drill groove 3 for inserting a positioning drill bit 21 is provided on the end of the positioning drill body 2 away from the mounting hole groove 12. The extension direction of the drill groove 3 is coaxial with the extension direction of the positioning drill body 2. Limit grooves 31 are provided on two opposite inner walls of the drill groove 3. The two limit grooves 31 are symmetrically distributed with the rotation axis of the positioning drill body 2 as the center. The limit grooves 31 start from the end of the positioning drill body 2 away from the abutment surface 16 and extend along the extension direction of the positioning drill body 2 toward the abutment surface 16. A limit block 32 for inserting and sliding in the limit groove 31 is fixedly connected to the side wall of the positioning drill bit 21. The limit block 32 corresponds to the limit groove 31 one-to-one. The limit block 32 is inserted from the opening surface of the limit groove 31 on the end of the positioning drill body 2 away from the abutment surface 16 and slides toward the depth of the drill groove 3 along the extension direction of the limit groove 31. The outer wall of the limit block 32 is in contact with the inner wall of the limit groove 31.

[0045] Reference Figure 4 and Figure 5 A guiding bevel 33 is formed on the end of the positioning drill bit 21 inserted into the drill groove 3. The bottom surface of the positioning drill bit 21 contacts the bottom wall of the drill groove 3. The guiding bevel 33 extends from one side of the bottom surface of the positioning drill bit 21 to the other side, and the guiding bevel 33 is inclined in a direction that the closer it approaches the other side, the closer it is to the tip 23. A brazing cavity 34 for clamping brazing material is formed between the guiding bevel 33 and the bottom wall of the drill groove 3. The guiding bevel 33 guides the brazing material on the bottom wall of the drill groove 3 into the brazing cavity 34 to clamp the brazing material.

[0046] Example 3:

[0047] The difference from Example 2 is that Figure 6 There are two guiding bevels 33, and the two guiding bevels 33 extend obliquely from the two opposite side edges of the bottom surface of the positioning drill bit 21 toward the middle end. The guiding bevels 33 are inclined in a direction that the closer they are to the middle section of the bottom surface of the positioning drill bit 21, the farther away from the tip 23. The two guiding bevels 33 are connected at the middle section of the bottom surface of the positioning drill bit 21. There is an arc chamfer 35 on the upper stroke of the position where the two guiding bevels 33 are connected. The arc chamfer 35 is also provided between the guiding bevel 33 and the ground side of the positioning drill bit 21.

[0048] Example 4:

[0049] The difference from Example 3 is that Figure 7 The guiding slope 33 is inclined in a direction in which the middle section closer to the bottom surface of the positioning drill bit 21 is closer to the tip 23 .

[0050] The above are all preferred embodiments of the present application, and are not intended to limit the scope of protection of the present application. Therefore, any equivalent changes made based on the structure, shape, and principle of the present application should be included in the scope of protection of the present application.

Claims

1. A hole opener, characterized in that: The invention comprises a circular saw cover (1) for opening a hole, wherein a positioning drill body (2) is provided on the circular saw cover (1), a positioning drill bit (21) is brazed on the positioning drill body (2), and the positioning drill bit (21) is used to drill into a contact surface before the circular saw cover (1) to position the circular saw cover (1).

2. The hole opener according to claim 1, characterized in that: At least three drilling surfaces (22) are formed on the end of the positioning drill bit (21), and a plurality of the drilling surfaces (22) intersect to form a tip (23).

3. The hole opener according to claim 1, characterized in that: The circular saw cover (1) is provided with a mounting rod (11), an inner wall of the circular saw cover (1) is provided with a mounting hole groove (12) for inserting the positioning drill body (2), an outer wall of the mounting rod (11) is provided with a tightening hole (13), the tightening hole (13) is communicated with the mounting hole groove (12), a tightening member (14) is inserted into the tightening hole (13), and the tightening member (14) is used to tighten against the positioning drill body (2).

4. The hole opener according to claim 3, characterized in that: Threaded grooves (15) are provided on the inner wall of the fastening hole (13) and the fastening member (14), and the fastening member (14) is threadedly connected to the fastening hole (13) via the threaded grooves (15).

5. The hole opener according to claim 3, characterized in that: A pressing surface (16) is provided on the positioning drill body (2), and the pressing surface (16) is tightly fitted against the end of the pressing member (14).

6. The hole opener according to claim 3, characterized in that: An extension sleeve (17) is provided on the circular saw cover (1), and the extension sleeve (17) is sleeved outside the mounting rod (11), and the extension sleeve (17) surrounds the mounting hole groove (12) inside.

7. The hole opener according to claim 1, characterized in that: A drill groove (3) for inserting the positioning drill bit (21) is provided on the end of the positioning drill body (2), a limiting groove (31) is provided on the inner wall of the drill groove (3), and a limiting block (32) is provided on the positioning drill bit (21) for inserting and sliding in the limiting groove (31).

8. The hole opener according to claim 7, characterized in that: The number of the limiting grooves (31) and the limiting blocks (32) is at least two, a plurality of the limiting grooves (31) are distributed on the inner wall of the drilling groove (3), and a plurality of the limiting blocks (32) are distributed on the outer wall of the positioning drill bit (21).

9. The hole opener according to claim 7, characterized in that: A guiding bevel (33) is provided on the end of the positioning drill bit (21) inserted into the drill groove (3), and a brazing cavity (34) for clamping the brazing material is formed between the guiding bevel (33) and the bottom wall of the drill groove (3). The guiding bevel (33) guides the brazing material on the bottom wall of the drill groove (3) into the brazing cavity (34) to clamp the brazing material.

10. The hole opener according to claim 9, characterized in that: There are two guide bevels (33), and the two guide bevels (33) are connected. A circular arc chamfer (35) is provided at the position where the two guide bevels (33) are connected. The circular arc chamfer (35) is also provided between the guide bevel (33) and the side wall of the positioning drill bit (21).

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