Drill having chamfering function and chamfering unit therefor

Abstract

Disclosed is a chamfering unit capable of significantly reducing process time and costs by simultaneously performing drilling, upper surface chamfering, and lower surface chamfering work with one tool, and easily replacing a chamfering cutter using a fixture made of a screw member. The chamfering unit comprises: a clip-type spring having an inclined support unit; a chamfering cutter holder having a spring seating unit on which the clip-type spring can be seated on the inner surface thereof and a fixing unit having a through-hole for fixing same to a drill body; a chamfering cutter having an inclined cutting unit formed at the outer upper end and outer lower end thereof and having a wedge-shaped inclined insertion unit provided at the inner end thereof so as to be inserted into the inclined support unit and elastically supported by the clip-type spring; and a fixture for fixing the chamfering cutter holder to the drill body through the through-hole.

Description

Drill with chamfering function and chamfering unit therefor

[0001] The present invention relates to tools, and more particularly to improvements in drills used for drilling holes or forming grooves.

[0002] Generally, the term "drill" refers to a twist drill with a spiral cutting edge that drills circular holes. Also known as a solid drill. Drills are typically made of high-speed steel, but some have tips made of materials like cemented carbide attached to the end of the blade, called insert drills. There are also drills with changeable heads.

[0003] A drill like the above is mounted on the main shaft of a drilling machine and rotates up and down to drill a hole in a workpiece.

[0004] Traditionally, holes were drilled or grooves were formed, and chamfers or chamfers on the edges of holes and other surfaces were formed through a separate machining process using a separate chamfering tool. The process of forming chamfers or chamfers is called chamfering, chamfering, or chamfering. Forming chamfers or chamfers through a separate machining process is cumbersome and reduces work efficiency.

[0005] To address the drawbacks of forming chamfers as separate machining processes, drills capable of simultaneously drilling holes and chamfering are being developed. Related prior art is disclosed in Patent Publication No. 10-2005-0004509 (Title: Counterboring and Chamfering Integrated Drill Tool, Inventor: Park Geon-wook).

[0006] An object of the present invention is to provide a drill having a chamfering function capable of forming a chamfered surface or chamfer around the hole on the upper and lower surfaces of a workpiece along with the operation of drilling a hole in the workpiece.

[0007] Another object of the present invention is to provide a drill having a chamfering function with a simple configuration.

[0008] Another object of the present invention is to provide a chamfering unit for a drill having a chamfering function of the present invention.

[0009] Another object of the present invention is to provide a drill having a chamfering function in which the chamfering unit can be replaced.

[0010] A drill having a chamfering function according to the present invention comprises a drill body having a drill blade portion and a chamfering unit mounting portion formed above the drill blade portion; and a chamfering unit having a chamfering cutter installed on the chamfering unit mounting portion and elastically supported so as to be movable in the transverse direction of the drill body, a portion of which protrudes laterally of the drill body, and which, when a hole is machined in a workpiece by the drill blade portion, is raised and lowered together with the drill body to form a chamfer on the upper edge and the lower edge of the workpiece around the hole, respectively, and is pressed by the workpiece to retreat into the drill body so as to pass through the hole, and a portion of which protrudes laterally of the drill body when passing through the hole.

[0011] It is preferable that the chamfering unit include a clip-type spring having an inclined support portion for elastically supporting the chamfering cutter; a chamfering cutter holder having a spring mounting portion on which the clip-type spring can be mounted and a fixing portion for fixing the chamfering cutter holder to the drill body; and a fixing member for fixing the chamfering cutter holder to the drill body.

[0012] The chamfering cutter preferably includes an inclined cutting portion formed inclinedly to form a chamfer on the upper edge and the lower edge, respectively, at the lower and upper ends of the laterally protruding portion; and a wedge-shaped inclined insertion portion formed on the inner end and inserted into the inclined support portion to be elastically supported by the clip-type spring.

[0013] It is preferable that the above chamfering unit mounting portion has a cutter insertion hole into which the chamfering cutter can be movably inserted; and a fastening hole formed in the drill body on one side of the cutter insertion hole and into which the fixing member can be fastened.

[0014] A guide hole may be formed in the transverse direction of the drill body in the chamfering cutter, and the fixing member may be a screw member that is coupled to the fastening hole through a through hole formed in the fixing member to fix the chamfering cutter holder to the drill body, and may have a guide pin formed at an inner end thereof that is inserted into the guide hole to guide the movement of the chamfering cutter.

[0015] The above guide pin can function as a stopper to limit the movement distance of the chamfering cutter.

[0016] It is preferable that a guide portion is formed in the above chamfering unit mounting portion, and a guide portion that is guided by the guide portion is formed in the above chamfering cutter holder.

[0017] A chamfering unit according to the present invention comprises: a clip-type spring having an inclined support portion; a chamfering cutter holder having a spring mounting portion on the inner surface of which the clip-type spring can be mounted and a fixing portion having a through hole for fixing to a drill body; a chamfering cutter having an inclined cutting portion formed at the outer upper and lower ends and a wedge-shaped inclined insertion portion inserted into the inclined support portion at the inner end and elastically supported by the clip-type spring; and a fixing member for fixing the chamfering cutter holder to the drill body through the through hole.

[0018] It is preferable that a guide hole is formed in the transverse direction of the drill body in the chamfering cutter, and the fixing member is a screw member that is coupled to a fastening hole of the drill body through a through hole formed in the fixing member to fix the chamfering cutter holder to the drill body, and a guide pin is formed at the inner end thereof to be inserted into the guide hole and guide the movement of the chamfering cutter.

[0019] The above guide pin can prevent the chamfering cutter from moving outward from the chamfering cutter holder.

[0020] It is preferable that the above-mentioned inclined cutting portion is formed to be inclined in both the up-down and left-right directions.

[0021] According to the present invention, drilling, upper surface chamfering, and lower surface chamfering can be performed simultaneously with one tool, thereby drastically reducing process time and cost.

[0022] According to the present invention, the chamfering cutter can be easily replaced using a screw-type fixing member.

[0023] According to the present invention, the chamfering cutter is guided by the guide pin and enters the inside of the drill body or protrudes outside the drill body, so the operation is stable.

[0024] According to the present invention, the size of the elastic support force received from the clip-type spring can be adjusted not only by adjusting the design variables of the clip-type spring but also by adjusting the inclination angle of the inclined insertion portion of the chamfering cutter, so that it is easy to design according to the needs of the field.

[0025] Figure 1 is a perspective view of a drill having a chamfering function according to the present invention;

[0026] Figure 2 is a front view of the drill body in which the chamfering unit mounting portion is formed.

[0027] Figure 3 is a right side view of the drill body of Figure 2.

[0028] Figure 4 is an exploded perspective view of a chamfering unit according to the present invention;

[0029] Figure 5 is a front view of a drill having a chamfering function according to the present invention;

[0030] Figure 6 is a right side view of Figure 5;

[0031] Figure 7 is a plan view for explaining the configuration of the fixture.

[0032] Fig. 8 is a plan view for explaining the configuration of the chamfering cutter holder.

[0033] Fig. 9 is a plan view of a chamfering cutter;

[0034] Figure 10 is a drawing for explaining the design variables of the clip-type spring and chamfering cutter.

[0035] Figures 11 (a) to (d) are drawings showing the process of mounting a chamfering unit according to the present invention to a drill body as viewed from above.

[0036] Figures 12 (a) to (d) are side views showing the process of mounting a chamfering unit according to the present invention to a drill body.

[0037] Figures 13 (a) to (g) are drawings sequentially showing a hole forming and chamfering process using a drill having a chamfering function according to the present invention.

[0038] 10: Workpiece 12: Hole

[0039] 14: Upper chamfer 16: Lower chamfer

[0040] 100: Chamfering unit 110: Chamfering cutter

[0041] 112: Inclined cutting section 114: Inclined insertion section

[0042] 116: Guide hole 120: Clip-type spring

[0043] 122: Elastic part 122a: Base

[0044] 122b: Elastic arm 124: Inclined support

[0045] 130: Chamfering cutter holder 132: Spring mounting part

[0046] 134: Fixed part 136: Through hole

[0047] 138: Guide part 140: Fixture

[0048] 142: Spiral 144: Guide pin

[0049] 200: Drill with chamfering function

[0050] 210: Drill body 212: Drill bit

[0051] 212a: Drill tip 220: Chamfering unit mounting part

[0052] 222: Cutter insertion hole 224: Fastening hole

[0053] 226: Information Department

[0054] Hereinafter, a preferred embodiment of the present invention will be described in detail with reference to the attached drawings.

[0055] Referring to FIGS. 1 to 9, a drill (200) having a chamfering function according to the present invention has a drill body (210) and a chamfering unit (100). The drill body (210) has a drill blade portion (212). A chamfering unit mounting portion (220) is formed above the drill blade portion (212).

[0056] The chamfering unit mounting portion (220) is a portion where the chamfering unit (100) is mounted and fixed, and has a cutter insertion hole (222) into which a chamfering cutter (110) constituting the chamfering unit (100) can be movably inserted, and a fastening hole (224) formed in the drill body (210) on one side of the cutter insertion hole (222) and into which a fixture (140) can be fastened. A fastening hole (224) having a female spiral formed on the inner circumference is used. Preferably, the cutter insertion hole (222) is formed to penetrate the drill body (210) laterally. A guide portion (226) is formed in the chamfering unit mounting portion (220). In this embodiment, the guide portions (226) are exemplified as being formed in a pair in a V-shaped groove shape at positions facing each other vertically (see FIG. 3). It goes without saying that the cross-sectional shape of the guide portions (226) may be changed.

[0057] The chamfering unit (100) installed in the chamfering unit mounting portion (220) has a chamfering cutter (110). Preferably, the chamfering cutter (110) is movable in the transverse direction of the drill body (210) and is elastically supported so that a portion thereof protrudes laterally from the drill body (210). When a hole is machined in a workpiece by the drill blade portion (212), the chamfering cutter (110) is raised and lowered together with the drill body (210) to form chamfers on the upper and lower edges of the workpiece around the hole, respectively, and is pressed by the workpiece to retreat into the drill body (210) so as to pass through the hole, and when passing through the hole, a portion thereof protrudes laterally from the drill body (210) again.

[0058] The chamfering cutter (110) has an inclined cutting portion (112) for machining a chamfer. The inclined cutting portion (112) is formed on the upper and lower edges of the laterally protruding portion, and is formed to be inclined to fit the chamfer to be machined. The inclined cutting portion (112) formed on the lower edge is for forming a chamfer on the upper surface around the hole of the workpiece, and the inclined cutting portion (112) formed on the upper edge is for forming a chamfer on the lower surface around the hole of the workpiece. By manufacturing the lower and upper inclined cutting portions (112) by variously adjusting the inclination angles, it is possible to provide a drill (200) having a chamfering function capable of chamfering the upper and lower surfaces of a hole at various chamfering angles.

[0059] An inclined insertion portion (114) is formed on the inner end of the chamfering cutter (110).

[0060] The inclined insertion portion (114) is formed in a wedge shape that is inserted into the inclined support portion (124) and elastically supported by a clip-type spring (120). In addition, a guide hole (116) is formed in the transverse direction of the drill body (210) in the chamfering cutter (110). The guide hole (116) is for allowing the chamfering cutter (110) to be guided by the guide pin (144) when moving in the rotational direction of the drill body (210). The material of the chamfering cutter (110) is suitably made of HSS (high-speed steel) or WC (tungsten carbide).

[0061] A chamfering unit (100) having a chamfering cutter (110) as described above is configured with a clip-type spring (120), a chamfering cutter holder (130), and a fixture (140). The clip-type spring (120) has an elastic portion (122) that provides elasticity and an inclined support portion (124) that extends obliquely outward from the elastic portion (122) to elastically support the inclined insert portion (114) of the chamfering cutter (110). Referring to FIG. 4 and FIG. 10 together, the elastic portion (122) is configured with a plate-shaped base (122a) and elastic arms (122b) that are bent obliquely in a direction approaching each other at both ends of the base (122a). The inclined support portions (124) are arranged obliquely in a direction away from the elastic portion (122). It is preferable that the clip-type spring (120) be made of spring steel.

[0062] The chamfering cutter holder (130) has a spring mounting portion (132) on which a clip-type spring (120) can be mounted and a fixing portion (134) for fixing to the drill body (210). Preferably, a guided portion (138) guided by a guide portion (226) is formed on the upper and lower surfaces of the chamfering cutter holder (130). The guide portion (226) guides the guided portion (138) of the chamfering cutter holder (130) when the chamfering cutter holder (130) is mounted on the chamfering unit mounting portion (220), thereby allowing the chamfering cutter holder (130) to be easily and stably mounted. The fixing portion (134) is for fixing the chamfering cutter holder (130) to the drill body (210). In this embodiment, the fixed portion (134) is formed in a direction approximately perpendicular to the portion where the spring mounting portion (132) and the guide portion (138) are formed. A hole (136) is formed in this fixed portion (136). The hole (136) has a portion formed as a conical surface that gradually narrows from the outside to the inside.

[0063] The fixture (140) is for fixing the chamfering cutter holder (130) to the drill body (210). The fixture (140) preferably has a truncated cone-shaped head and is formed of a screw member having a male helix (142). A guide pin (144) is formed at the inner end of the fixture (140) to be inserted into a guide hole (116) and to guide the movement of the chamfering cutter (110). The guide pin (144) can also function as a stopper to limit the movement distance of the chamfering cutter (110) and also prevent the chamfering cutter (110) from being dislodged to the outside of the chamfering cutter holder (130).

[0064] That is, in a state where the chamfering unit (100) is mounted on the chamfering unit mounting portion (220), the fixing member (140) is coupled to the fastening hole (224) through the through hole (136) formed in the fixing portion (134) of the chamfering cutter holder (130) to fix the chamfering cutter holder (130) to the drill body (210). The chamfering unit (100) is stably fixed to the drill body (210) by the fixing member (140).

[0065] Although the drawings in the above embodiments illustrate the present invention based on an insert drill, the present invention can also be applied to other types of drills, such as a general-purpose solid drill or a head changeable drill.

[0066] Referring to (a) and (b) of FIG. 10, the design variables of the clip-type spring (120) are the angle α° between the elastic arms on both sides constituting the elastic part (122), the length (height in FIGS. 4 and 6) of the clip-type spring (120), the thickness t, the bending radius R of the elastic arm (122b) bent from the base (122a), and the design variable of the chamfering cutter (110) is the angle θ° of the inclined insertion portion (114). The combination of these five design variables determines the amount by which the chamfering cutter (110) enters the clip-type spring (120) or the inside of the drill body (210) with respect to the external force (F). The chamfering amount varies depending on the five design variables and the shear strength of the workpiece material being machined. The chamfering cutter (110) is constrained in the Y direction, which is the left-right direction, and the Z direction, which is the up-down direction, so that F y and F z No displacement occurs due to F x Displacement occurs only according to the rigidity of the clip-type spring (120). As the chamfering cutter (110) enters the clip-type spring (120), the angle β° between the spread elastic arms (122b) on both sides decreases.

[0067] The drill (200) having a chamfering function according to the present invention as described above is a tool capable of drilling and chamfering (bevelling) the upper and lower surfaces of a workpiece in a single process, and a chamfering cutter (110), which is a chamfering blade, is inserted into the drill body (210) and supported by a clip-type spring (120), so that after drilling, the chamfering cutter (110) performs upper surface chamfering and is pushed into the drill body (210), and when the chamfering cutter (110) exits the processing hole, it returns to its original position by the spring force. When the rotating drill (200) having a chamfering function exits the hole in the opposite direction, the lower surface chamfering is performed again by the chamfering cutter (110).

[0068] Referring to the drawings of FIGS. 11 and 12, a process for mounting a chamfering unit according to the present invention to a chamfering unit mounting portion will be described.

[0069] First, as shown in (a) of Fig. 11 and (a) of Fig. 12, a clip-type spring (120) is inserted into a spring mounting portion (132) formed in a chamfering cutter holder (130) and mounted.

[0070] Meanwhile, as shown in (b) of Fig. 11 and (b) of Fig. 12, a chamfering cutter (110) is inserted into a cutter insertion hole (222) formed in the drill body (210).

[0071] Then, as shown in (c) of Fig. 11 and (c) of Fig. 12, a chamfering cutter holder (130) equipped with a clip-type spring (120) is mounted on a chamfering unit mounting portion (220), and a fixing member (140) is coupled to a fastening hole (224) through a through hole (136) to fix the chamfering cutter holder (130) to the drill body (210). A guide pin (144) installed at the end of the fixing member (140) is inserted into a guide groove (116) formed in the chamfering cutter (110).

[0072] The state in which the chamfering unit (100) according to the present invention is mounted on the chamfering unit mounting portion (220) of the drill body (210) through the above process is as shown in (d) of FIG. 11 and (d) of FIG. 12.

[0073] The drill (200) having a chamfering function according to the present invention, assembled through the above process, can be installed in a tool holder of a drilling machine and used for drilling work.

[0074] Referring to FIG. 13 and the preceding drawing, the process of drilling and chamfering using a drill (200) having a chamfering function according to the present invention is described as follows.

[0075] When a drill (200) having a chamfering function according to the present invention is mounted on a drilling machine, as shown in (a) of Fig. 13, the drill (200) having a chamfering function is lowered toward a workpiece (10) fixed to a vice or the like while rotating, and the drill blade (212) below the chamfering cutter (110) drills a hole (12).

[0076] When a portion of the chamfering cutter (110) protruding laterally from the drill body (210) reaches the upper surface of the workpiece (10) around the hole (12), the lower inclined cutting portion (112) rotates together with the drill body (210) to perform upper surface chamfering processing on the workpiece (10), thereby forming an upper chamfer (14).

[0077] As the drill (200) having a chamfering function descends, the chamfering area increases, and as the chamfering area increases, the force that presses the chamfering cutter (110) inward increases, and when it exceeds the support force of the clip-type spring (120), as shown in (c) of FIG. 13, the chamfering cutter (110) enters the inside of the drill body (210) of the drill (200) having a chamfering function, and passes through the hole (12) in that state.

[0078] As shown in (d) of Fig. 13, when the chamfering cutter (110) comes out of the hole (12), the chamfering cutter (110) is protruded outward from the drill body (210) by the clip-type spring (120).

[0079] When the drill (200) having a chamfering function is raised while the chamfering cutter (110) protrudes outward from the drill body (210), as shown in (e) of FIG. 13, the upper inclined cutting portion (112) performs a lower chamfering process on the workpiece (10) to form a lower chamfer (16). As the chamfering processing area increases, the chamfering cutter (110) enters the drill body (210) again and passes through the hole (12) while making contact with the inner surface of the hole (12), as shown in (f) of FIG. 13. When the chamfering cutter (110) exits the hole (12), as shown in (g) of FIG. 13, a portion of the chamfering cutter (110) protrudes laterally from the drill body (210) again by the clip-type spring (120).

[0080] That is, when using a drill (200) having a chamfering function according to the present invention, while drilling a hole (12), chamfering can be performed around the hole on the upper and lower surfaces of the workpiece (10) to form an upper chamfer (14) and a lower chamfer (16).

[0081] The present invention has the potential to be used to manufacture drills with a chamfering function. The present invention can be used to manufacture not only insert drill-type drill tools, but also general-purpose solid drills and head-changeable drills.

Claims

1. A drill body having a drill blade and a chamfering unit mounting portion formed above the drill blade; and A drill having a chamfering function, characterized by including a chamfering unit having a chamfering cutter that is installed in the chamfering unit mounting portion and elastically supported so as to be movable in the transverse direction of the drill body, a portion of which protrudes laterally from the drill body, and which, when a hole is machined in a workpiece by the drill blade portion, moves up and down together with the drill body to form a chamfer on the upper and lower edges of the workpiece around the hole, respectively, and is pressed by the workpiece to retreat into the drill body and pass through the hole, and a portion of which protrudes laterally from the drill body when passing through the hole.

2. In the first paragraph, the chamfering unit, A clip-type spring having an inclined support portion for elastically supporting the above chamfering cutter; A chamfering cutter holder having a spring mounting portion on which the clip-type spring can be mounted and a fixing portion for fixing to the drill body; and A drill having a chamfering function, characterized by including a fixing member for fixing the chamfering cutter holder to the drill body.

3. In the second paragraph, the chamfering cutter, An inclined cutting portion formed to be inclined to form a chamfer on the upper edge and the lower edge, respectively, at the lower and upper ends of the portion protruding laterally; and A drill having a chamfering function, characterized by including a wedge-shaped inclined insert formed on the inner side and inserted into the inclined support portion and elastically supported by the clip-type spring.

4. In the third paragraph, the chamfering unit mounting part, A cutter insertion hole into which the chamfering cutter can be movably inserted; and A drill having a chamfering function, characterized in that it has a fastening hole formed in the drill body on one side of the cutter insertion hole and into which the fastener can be fastened.

5. In the fourth paragraph, a guide hole is formed in the chamfering cutter in the transverse direction of the drill body, A drill having a chamfering function, characterized in that the fixing member is a screw member that is coupled to the fastening hole through a through hole formed in the fixing part to fix the chamfering cutter holder to the drill body, and includes a guide pin formed on the inner end thereof to be inserted into the guide hole to guide the movement of the chamfering cutter.

6. A drill having a chamfering function, characterized in that in the fifth paragraph, the guide pin includes a stopper function that limits the movement distance of the chamfering cutter.

7. A drill having a chamfering function, characterized in that in the fourth paragraph, a guide portion is formed in the chamfering unit mounting portion, and a guide portion that is guided by the guide portion is formed in the chamfering cutter holder.

8. Clip-type spring with inclined support; A chamfering cutter holder having a spring mounting portion on the inner surface into which the clip-type spring can be mounted and a fixing portion having a hole for fixing to the drill body; A chamfering cutter having a slanted cutting portion formed at the outer upper and lower ends and a wedge-shaped slanted insert portion inserted into the slanted support portion at the inner end and elastically supported by the clip-type spring; and A chamfering unit characterized by including a fixing member for fixing the chamfering cutter holder to the drill body through the above-described hole.

9. In the 8th paragraph, a guide hole is formed in the transverse direction of the drill body in the chamfering cutter, A chamfering unit having a chamfering function, characterized in that the fixing member is a screw member that is coupled to a fastening hole of the drill body through a through-hole formed in the fixing member to fix the chamfering cutter holder to the drill body, and includes a guide pin formed at an inner end thereof to be inserted into the guide hole to guide the movement of the chamfering cutter.

10. A chamfering unit according to claim 9, characterized in that the guide pin prevents the chamfering cutter from moving outward from the chamfering cutter holder.

11. A chamfering unit according to claim 9, characterized in that the inclined cutting portion is formed to be inclined in both the up-down and left-right directions.

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