Cutter for machining counter bores on reverse side

Abstract

The utility model relates to the technical field of machining, in particular to a tool for machining reverse counter bores, which comprises a tool bar, a tool bit and a fastener, and one end of the tool bar is provided with a mounting section and a locking section; a front gasket is further included. A through hole is formed in the middle of the front gasket, a clamping key is arranged at the end of the through hole, and a key groove matched with the clamping key is formed in the blade end of the tool bit. A step surface is arranged at the joint of the mounting section and the cutter bar; a mounting hole capable of mutually transmitting torque with the mounting section is formed in the middle of the cutter head; the front gasket is sleeved on the mounting section and is clamped with the key slot of the tool bit through the clamping key, the tool bit is positioned between the front gasket and the fastener, and the fastener is connected with the locking section at the rear section of the tool bit. The front gasket is matched with the key groove in the blade end of the tool bit, the position of the key groove only bears axial acting force, torque is not transmitted, the key groove is not prone to cracking, meanwhile, the blade end is prevented from making direct contact with the tool bar through the front gasket, the position of a cutting edge is protected, and the service life of the tool bit is prolonged.

Description

TECHNICAL FIELD

[0001] The utility model relates to mechanical processing technical field especially relates to a kind of cutter of processing reverse face counterbore. BACKGROUND

[0002] Reverse face counterbore processing cutter is specially used to process counterbore on the reverse face of workpiece, which has wide application in mechanical processing field, especially in automobile, aviation, shipbuilding and other industries, and is particularly important for workpiece needing high-precision and high-quality counterbore processing.

[0003] The patent with patent number CN201920063909.X discloses a reverse dimpling cutter in prior art, which comprises a cutter bar, a cutter head, a gasket and a fastener. The cutter head and the gasket are sequentially sleeved on the cutter bar, and the fastener is sleeved and tightly connected on the cutter bar to limit the axial displacement of the cutter head and the gasket in the direction opposite to the pulling direction of the cutter bar. A key groove is formed in the non-working end of the cutter head, and a protrusion is arranged at one end of the gasket. The protrusion is clamped with the key groove to limit the relative rotation of the cutter head and the gasket. The mounting hole of the gasket is a waist-shaped hole, and a waist-shaped column adapted to the waist-shaped hole is arranged at the assembly position of the cutter bar and the waist-shaped hole to limit the rotation of the gasket on the cutter bar, thereby limiting the rotation of the cutter head on the cutter bar.

[0004] The patent has the following defects. First, the torque is transmitted between the cutter bar and the gasket through a short flat position (i.e. a waist-shaped structure). Due to the insufficient length of the flat position and the limited stress area, the force is concentrated, which is prone to deformation, thereby shortening the service life. Second, the torque is transmitted between the gasket and the cutter head through a key position structure, and the key groove of the cutter head is designed as an open end face key groove. Since the blade part of the cutter head is usually made of high-hardness material, the toughness is relatively low, and the key groove is prone to cracking under high load. UTILITY MODEL CONTENTS

[0005] To solve the problem of easy deformation and cracking of the reverse dimpling cutter structure in prior art, the utility model provides a cutter for processing reverse face counterbore, which has the characteristics of large stress area and the cutter head is not easy to crack.

[0006] A cutter for processing reverse face counterbore comprises a cutter bar, a cutter head and a fastener. One end of the cutter bar is provided with a mounting section and a locking section. A front gasket is further included. A through hole is arranged in the middle part of the front gasket, and a clamping key is arranged at the end of the through hole. A key groove matched with the clamping key is arranged at the blade end of the cutter head. A stepped surface is arranged at the connection position of the mounting section and the cutter bar. A mounting hole capable of limiting the mounting section in the circumferential direction and transmitting torque with each other is arranged in the middle part of the cutter head. The front gasket is sleeved on the mounting section and clamped with the key groove of the cutter head through the clamping key. The cutter head is located between the front gasket and the fastener, and the fastener is connected with the locking section at the rear section of the cutter head.

[0007] Further, a flat position structure is arranged on the side surface of the mounting section, and a flat hole structure matched with the flat position structure is arranged on the inner wall of the mounting hole.

[0008] Further, a strip-shaped slot is arranged outside the mounting segment, and a convex rib matched with the strip-shaped slot is arranged on the inner wall of the mounting hole.

[0009] Further, a rear washer is arranged between the tool head and the fastener.

[0010] Further, the locking segment is an external thread segment at the end of the tool bar, the fastener is a nut matched with the external thread, or the locking segment is an internal thread hole at the end of the tool bar, and the fastener is a screw matched with the internal thread hole.

[0011] Further, a pin hole is arranged at the outer end of the locking segment, and the fastener is a pin matched with the pin hole, so that the tool head is fixed on the tool bar through the pin.

[0012] The tool head of the utility model has the advantages of:

[0013] 1. The front washer is matched with the blade end key groove of the tool head, the key groove position only bears axial force and does not transmit torque, the key groove is not easy to crack, meanwhile, the setting of the front washer makes the blade end avoid direct contact with the tool bar, the blade position is protected, and the service life of the tool head is increased.

[0014] 2. The mounting segment adopts a flat position or a strip-shaped slot mode, the corresponding tool head mounting hole is matched with the structure of the mounting segment, the stress area of the torque transmission between the tool bar and the tool head is increased, the risk of cracking of the tool head made of high-hardness material in the use process is reduced, the risk of deformation of the tool bar is reduced, the service life of the structure is improved, meanwhile, the need of torque transmission can also be met.

[0015] 3. The step surface arranged on the tool bar and matched with the fastener limit the axial movement of the tool head, the tool setting is more convenient, the tool setting accuracy is improved, and the use convenience of the tool is increased. BRIEF DESCRIPTION OF DRAWINGS

[0016] Figure 1 It is a tool structure schematic view for machining reverse face counterbore in the utility model;

[0017] Figure 2 It is a structure exploded schematic view of the tool for machining reverse face counterbore in the utility model;

[0018] Figure 3 It is another structure exploded schematic view of the tool for machining reverse face counterbore in the utility model;

[0019] In the drawing: 1, tool bar; 2, tool head; 3, fastener; 4, mounting segment; 5, locking segment; 6, front washer; 7, through hole; 8, clamping key; 9, key groove; 10, step surface; 11, mounting hole; 12, flat position structure; 13, flat hole structure; 14, strip-shaped slot; 15, convex rib; 16, rear washer. DETAILED DESCRIPTION

[0020] The following is a further description of a tool for machining a reverse countersink according to the present invention in conjunction with specific embodiments.

[0021] like Figure 1 、 Figure 2 、 Figure 3 As shown, a tool for processing reverse countersunk holes includes a tool rod 1, a tool head 2 and a fastener 3. One end of the tool rod 1 is provided with a mounting section 4 and a locking section 5; it also includes a front washer 6; a through hole 7 is provided in the middle of the front washer 6, a key 8 is provided at the end of the through hole 7, and a key slot 9 matching the key 8 is provided at the cutting end of the tool head 2; a step surface 10 is provided at the connection between the mounting section 4 and the tool rod 1, and a mounting hole 11 is provided in the middle of the tool head 2 for circumferentially limiting the mounting section 4 and transmitting torque to each other; the front washer 6 is sleeved on the mounting section 4 and is clamped with the key slot 9 of the tool head 2 through the key 8, the tool head 2 is located between the front washer 6 and the fastener 3, and the fastener 3 is connected to the locking section 5 at the rear section of the tool head 2.

[0022] like Figure 2 、 Figure 3 As shown, in this solution, the key 8 on the front washer 6 is engaged with the keyway 9 at the cutting edge of the cutter head 2. The key 8 is only subjected to axial force and does not transmit torque. Therefore, it is not easy for the keyway 9 to crack. In addition, since a key structure is used at this position to transmit axial force, the cutting edge position is avoided, the fragile cutting edge is protected, and the service life of the cutter head 2 is increased.

[0023] The existing patents related to the background technology lack an axial limit design on the cutting edge of the cutter head 2, which allows the cutter head 2 to move axially along the tool arbor 1. This not only increases the difficulty of tool setting (the positional relationship between the cutting edge and the tool arbor 1 must be confirmed before machining), but also reduces the accuracy of tool setting. In this solution, the shaft axially limits the front position of the cutter head 2 through the step surface 10 on the tool arbor 1, and axially limits the rear position of the cutter head 2 through the fastener 3, so that the cutter head 2 will not move forward and backward on the tool arbor 1, which facilitates tool setting and helps to improve tool setting accuracy. In this embodiment, the tool arbor 1, the mounting section 4 and the locking section 5 are an integrated structure.

[0024] like Figure 2 As shown, the side of the mounting section 4 is provided with a flat position structure 12, and the inner wall of the mounting hole 11 is provided with a flat hole structure 13 that cooperates with the flat position structure. During the manufacturing process, the flat length of the mounting section 4 can be increased to make it cooperate with the flat hole structure 13 in the cutter head 2. The flat hole runs through the inside of the cutter head 2, which increases the force area when the cutter head 2 and the tool rod 1 transmit torque, and has better overall strength, which helps to reduce the risk of cracking of the cutter head made of high-hardness materials during use. Therefore, the material selection of the cutter head 2 can use a material with a higher hardness as a whole. Compared with the prior art that sets a step hole in the cutter head 2, the flat hole of the cutter head 2 in this solution is a through hole 7, which has a wider range of cutter head material selection, and there is less concern about the cutter head cracking when the cutter head cutting structure is designed.

[0025] As shown in Figure 3 the outer side of the mounting section 4 is provided with a strip-shaped groove 14, and the inner wall of the mounting hole 11 is provided with a convex rib 15 matched with the strip-shaped groove 14.

[0026] The coaxial matching precision of the tool head 2 and the tool bar 1 depends on the size of the arc matching surface in the connecting hole. The strip-shaped groove 14 and the convex rib 15 are beneficial to increase the arc matching area of the tool head 2 and the tool bar 1, and improve the coaxial matching precision of the tool bar 1 and the tool head 2. Meanwhile, the matching of the strip-shaped groove 14 and the convex rib 15 can also meet the torque transmission in the working process.

[0027] As shown in Figure 1 , Figure 2 , Figure 3 a rear gasket 16 is arranged between the tool head 2 and the fastener 3. By increasing the rear gasket 16, the pressure generated by the fastener 3 can be more evenly distributed at the rear end of the tool head 2, so as to reduce the local stress and prevent the damage of the rear end of the tool head 2 due to excessive pressure.

[0028] In the embodiment, the locking section 5 is an external thread section at the end of the tool bar 1, and the fastener 3 is a nut matched with the external thread; or the locking section 5 is an internal thread hole at the end of the tool bar 1, and the fastener 3 is a screw matched with the internal thread hole.

[0029] In other embodiments, the outer end of the locking section 5 is provided with a pin hole, and the fastener 3 is a pin matched with the pin hole, and the tool head 2 is fixed on the tool bar 1 through the pin (not shown in the figure), wherein the cap end size of the pin is greater than the hole diameter of the rear end of the tool head 2.

Claims

1. A tool for machining a reverse countersink, characterized in that: The utility model comprises a knife bar (1), a knife head (2), a fastener (3) and a front washer (6); a mounting section (4) and a locking section (5) are provided at one end of the knife bar (1); a through hole (7) is provided in the middle of the front washer (6), a key (8) is provided at the end of the through hole (7), and a keyway (9) matching with the key (8) is provided at the blade end of the knife head (2); a step surface (10) is provided at the connection between the mounting section (4) and the knife bar (1), and a mounting hole (11) is provided in the middle of the knife head (2) for circumferentially limiting the mounting section (4) and capable of transmitting torque to each other; the front washer (6) is sleeved on the mounting section (4) and is clamped with the keyway (9) of the knife head (2) through the key (8); the knife head (2) is located between the front washer (6) and the fastener (3), and the fastener (3) is connected to the locking section (5) at the rear section of the knife head (2).

2. The tool for machining a reverse countersink according to claim 1, characterized in that: A flat position structure (12) is provided on the side surface of the installation section (4), and a flat hole structure (13) matching with the flat position structure (12) is provided on the inner wall of the installation hole (11).

3. The tool for machining a reverse countersink according to claim 1, characterized in that: A strip groove (14) is provided on the outside of the mounting section (4), and a convex rib (15) matching the strip groove (14) is provided on the inner wall of the mounting hole (11).

4. The tool for machining a reverse countersink according to any one of claims 1 to 3, characterized in that: A rear washer (16) is provided between the cutter head (2) and the fastener (3).

5. The tool for machining a reverse countersink according to any one of claims 1 to 3, characterized in that: The locking section (5) is an external thread section at the end of the shank (1); the fastener (3) is a nut that matches the external thread; or the locking section (5) is an internal thread hole at the end of the shank (1), and the fastener (3) is a screw that matches the internal thread hole.

6. The tool for machining a reverse countersink according to claim 4, characterized in that: The locking section (5) is an external thread section at the end of the shank (1); the fastener (3) is a nut that matches the external thread; or the locking section (5) is an internal thread hole at the end of the shank (1), and the fastener (3) is a screw that matches the internal thread hole.

7. The tool for machining a reverse countersink according to any one of claims 1 to 3, characterized in that: The outer end of the locking section (5) is provided with a pin hole, and the fastener (3) is a pin that matches the pin hole, and the cutter head (2) is fixed to the cutter rod (1) through the pin.

8. The tool for machining a reverse countersink according to claim 4, characterized in that: The outer end of the locking section (5) is provided with a pin hole, and the fastener (3) is a pin that matches the pin hole, and the cutter head (2) is fixed to the cutter rod (1) through the pin.

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