Stepped drill for drilling composite material parts

Abstract

The utility model discloses a step drill used for drilling composite material parts, the step drill comprises a drilling cutting part, a countersinking cutting part and a drillstock, the drillstock is provided with a first rotary joint and a second rotary joint, the first rotary joint is provided with a first air inlet and a first air outlet, the second rotary joint is provided with a second air inlet and a second air outlet, and the first air inlet and the second air outlet are communicated with each other. A first through hole is formed in the counter sinking cutting part and the drill handle, a first inlet of the first through hole is communicated with a first air outlet of the first rotating joint, a first outlet of the first through hole is communicated with the drilling spiral chip groove, and a first air inlet of the first rotating joint is connected with an air compressor; the drill handle is provided with a second through hole, a second inlet of the second through hole is communicated with the countersinking spiral chip groove, a second outlet of the second through hole is communicated with a second air outlet of the second rotating connector, and a second air inlet of the second rotating connector is connected with the negative pressure dust collector. According to the utility model, powder cuttings are prevented from being accumulated in a drilling orifice area, and the powder cuttings are prevented from drifting to the air.

Description

Technical Field

[0001] The utility model relates to a drill bit used for drilling holes in mechanical processing, in particular to a step drill used for drilling composite material mechanical parts, belonging to the technical field of drilling tools. Background Art

[0002] Composite materials are two-phase or multi-phase structural materials made by mixing a soft and viscous matrix material with a high-strength and high-hardness fiber-reinforced material. Their anisotropy, low thermal conductivity, and low interlayer bonding strength make them typical difficult-to-process materials. For example, carbon fiber reinforced composite materials (CFRP), as an advanced composite material, have excellent comprehensive properties such as high specific strength, high specific stiffness, fatigue resistance, corrosion resistance, and excellent designability. They have been widely used in aerospace, automotive and other fields, such as the Airbus A350XWB. The extensive use of composite materials has greatly reduced the weight of aircraft structures and improved the fuel economy of aircraft. However, in order to achieve the connection and assembly of composite parts, a series of mechanical processing is required, and drilling is one of the most labor-intensive mechanical processing. Since composite materials show obvious anisotropy and stacking characteristics in the macroscopic view, their interlayer bonding strength is much lower than that in other directions. When drilling, due to the weak constraints of the entrance and exit positions, the drill tip is very likely to generate a large axial force, push open the outermost layers of materials, and cause delamination damage. The fiber bending caused by the inability to cut the fiber leads to tearing and burr damage. For this reason, researchers at home and abroad have developed a variety of drilling tools with different structural geometric forms. Among them, the step drill solves the technical problems of easy delamination of composite materials during drilling, and completes the entire processing process in one go, while achieving good hole surface quality. However, the step drill has the following two disadvantages in the process of drilling composite parts: (1) There is often a large amount of powdery chips accumulated in the drilling hole area, which reduces the hole-making accuracy on the one hand, and increases the friction resistance of the drill bit during cutting on the other hand, reducing the hole-making efficiency; (2) When the step drill is rotating and cutting, the powdery chips are scattered into the air, which not only causes damage to the human body, but also pollutes the surrounding environment. Summary of the invention

[0003] The technical problem to be solved by the utility model is to overcome the deficiencies of the prior art and to provide a step drill for drilling composite material parts which can avoid the accumulation of powdery chips in the drilling hole area and can prevent the powdery chips from scattering into the air and has a simple structure.

[0004] In order to solve the above technical problems, the utility model adopts such a step drill for drilling composite material parts, the step drill comprises a drilling cutting part with a small diameter section, a countersinking cutting part with a large diameter section and a drill shank, the drilling cutting part, the countersinking cutting part and the drill shank are coaxially arranged in sequence and the three are made in one piece, at least one drilling spiral chip removal groove for chip removal during drilling is provided on the drilling cutting part, at least one countersinking spiral chip removal groove for chip removal during countersinking is provided on the countersinking cutting part, a first rotary joint and a second rotary joint are installed on the drill shank, the first rotary joint is provided with a first air inlet and a first air outlet, the first rotary joint is provided with a first air inlet and a first air outlet, the first rotary joint is provided with a first air inlet and a first air outlet, and the second rotary joint is provided with a first air inlet and a first air outlet. The second rotary joint is provided with a second air inlet and a second air outlet, a first through hole is provided on the countersink cutting part and the drill shank, the first inlet of the first through hole is connected with the first air outlet of the first rotary joint, the first outlet of the first through hole is connected with the drilling spiral chip groove, and the first air inlet of the first rotary joint is connected with an air compressor; a second through hole is provided on the drill shank, the second inlet of the second through hole is connected with the countersink spiral chip groove, the second outlet of the second through hole is connected with the second air outlet of the second rotary joint, and the second air inlet of the second rotary joint is connected with a negative pressure vacuum cleaner.

[0005] As a preferred embodiment of the utility model, the drilling cutting portion is provided with two drilling spiral chip removal grooves arranged at intervals for chip removal during drilling, and the first through hole has two and is arranged at intervals, and the countersinking cutting portion is provided with two countersinking spiral chip removal grooves arranged at intervals for chip removal during countersinking, and the second through hole has two and is arranged at intervals.

[0006] After adopting the above structure, the utility model has the following beneficial effects:

[0007] Since the utility model arranges a first rotary joint and a second rotary joint on the drill shank, the first rotary joint is provided with a first air inlet and a first air outlet, the second rotary joint is provided with a second air inlet and a second air outlet, a first through hole is provided on the countersink cutting portion and the drill shank, a first inlet of the first through hole is connected to a first air outlet of the first rotary joint, a first outlet of the first through hole is connected to a drilling spiral chip removal groove, and the first air inlet of the first rotary joint is connected to an air compressor; a second through hole is provided on the drill shank, a second inlet of the second through hole is connected to the countersink spiral chip removal groove, and a second outlet of the second through hole is connected to the second rotary joint. The second air outlet is connected, and the second air inlet of the second rotary joint is connected to the negative pressure vacuum cleaner. Therefore, when working, the compressed air output from the air compressor is blown at positive pressure to the drilling spiral chip groove through the first through hole, so as to avoid the accumulation of powdered chips in the drilling hole mouth area and reduce the friction resistance of the drill bit during cutting, thereby improving the hole forming accuracy and hole forming efficiency. At the same time, the negative pressure vacuum cleaner performs negative pressure vacuuming to the countersinking spiral chip groove through the second through hole, and the powdered chips in the countersinking spiral chip groove are timely removed and collected and stored, so as to prevent the powdered chips from floating into the air, thereby avoiding damage to the human body and pollution to the surrounding environment.

[0008] The utility model has the advantages of simple structure, convenient manufacture and improved processing quality of composite material parts. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The specific implementation of the utility model is further described in detail below in conjunction with the accompanying drawings.

[0010] Figure 1 The utility model is a front view schematic diagram of a step drill for drilling composite material parts.

[0011] Figure 2 for Figure 1 A three-dimensional schematic diagram of . DETAILED DESCRIPTION

[0012] See also Figure 1 , Figure 2A step drill for drilling composite material parts is shown, the step drill 1 comprises a drilling cutting part 1-1 of a small diameter section, a countersinking cutting part 1-2 of a large diameter section and a drill shank 1-3, the drilling cutting part 1-1, the countersinking cutting part 1-2 and the drill shank 1-3 are coaxially arranged in sequence and are made of one piece, the drilling cutting part 1-1 is provided with at least one drilling spiral chip removal groove 2 for chip removal during drilling, the countersinking cutting part 1-2 is provided with at least one countersinking spiral chip removal groove 3 for chip removal during countersinking, a commercially available first rotary joint 4 and a second rotary joint 5 are installed on the drill shank 1-3, when working, the first rotary joint 4 and the second rotary joint 5 are connected to the frame of the processing equipment, the frame is not shown in the figure, the first rotary joint 4 is provided with a first air inlet 4a and a first air outlet 4b, The second rotary joint 5 is provided with a second air inlet 5a and a second air outlet 5b, and a first through hole 6 is opened on the countersinking cutting part 1-2 and the drill shank 1-3, the first inlet 6a of the first through hole 6 is connected with the first air outlet 4b of the first rotary joint 4, the first outlet 6b of the first through hole 6 is connected with the drilling spiral chip groove 2, and the first air inlet 4a of the first rotary joint 4 is connected to an air compressor; a second through hole 7 is opened on the drill shank 1-3, the second inlet 7a of the second through hole 7 is connected with the countersinking spiral chip groove 3, the second outlet 7b of the second through hole 7 is connected with the second air outlet 5b of the second rotary joint 5, and the second air inlet 5a of the second rotary joint 5 is connected to a negative pressure vacuum cleaner, and the air compressor and negative pressure vacuum cleaner are not shown in the figure.

[0013] As a preferred embodiment of the present invention, Figure 1 , 2 As shown, the drilling cutting portion 1-1 is provided with two drilling spiral chip removal grooves 2 arranged at intervals for chip removal during drilling, the first through holes 6 are two and arranged at intervals, and the two first through holes 6 correspond to the corresponding drilling spiral chip removal grooves 2 respectively, and the countersinking cutting portion 1-2 is provided with two countersinking spiral chip removal grooves 3 arranged at intervals for chip removal during countersinking, and the second through holes 7 are two and arranged at intervals, and the two second through holes 7 correspond to the corresponding countersinking spiral chip removal grooves 3 respectively.

[0014] When the utility model is working, the compressed air output from the air compressor is blown at positive pressure to the drilling spiral chip groove 2 through the first through hole 6, so as to avoid the accumulation of powdery chips in the drilling hole mouth area and reduce the friction resistance of the drill bit during cutting. At the same time, the negative pressure vacuum cleaner is vacuuming the countersinking spiral chip groove 3 at negative pressure through the second through hole 7, so as to timely remove and collect and store the powdery chips in the countersinking spiral chip groove 3, and prevent the powdery chips from floating into the air, thereby avoiding damage to the human body and pollution to the surrounding environment.

[0015] After trial use, the utility model avoids the accumulation of powder and chips in the drilling hole area, prevents the powder and chips from drifting into the air, improves the processing quality of composite material parts, has a simple structure, and has achieved good practical effects.

Claims

1. A step drill for drilling composite material parts, the step drill (1) comprising a drilling cutting portion (1-1) with a small diameter section, a countersinking cutting portion (1-2) with a large diameter section and a drill shank (1-3), the drilling cutting portion (1-1), the countersinking cutting portion (1-2) and the drill shank (1-3) being coaxially arranged in sequence and integrally formed, the drilling cutting portion (1-1) being provided with at least one drilling spiral chip removal groove (2) for chip removal during drilling, and the countersinking cutting portion (1-2) being provided with at least one countersinking spiral chip removal groove (3) for chip removal during countersinking, characterized in that: A first rotary joint (4) and a second rotary joint (5) are mounted on the drill shank (1-3); the first rotary joint (4) is provided with a first air inlet (4a) and a first air outlet (4b); the second rotary joint (5) is provided with a second air inlet (5a) and a second air outlet (5b); a first through hole (6) is provided on the countersink cutting portion (1-2) and the drill shank (1-3); a first inlet (6a) of the first through hole (6) is connected to a first air outlet (4b) of the first rotary joint (4); and the first through hole (6) The first outlet (6b) of the drill bit (1-3) is connected to the drilling spiral chip removal groove (2), and the first air inlet (4a) of the first rotary joint (4) is connected to an air compressor; a second through hole (7) is provided on the drill shank (1-3), a second inlet (7a) of the second through hole (7) is connected to the countersinking spiral chip removal groove (3), a second outlet (7b) of the second through hole (7) is connected to a second air outlet (5b) of the second rotary joint (5), and the second air inlet (5a) of the second rotary joint (5) is connected to a negative pressure vacuum cleaner.

2. The step drill for drilling composite material parts according to claim 1, characterized in that: The drilling cutting portion (1-1) is provided with two drilling spiral chip removal grooves (2) arranged at intervals for chip removal during drilling, the first through holes (6) are provided with two and arranged at intervals, the countersinking cutting portion (1-2) is provided with two and arranged at intervals for chip removal during countersinking, and the second through holes (7) are provided with two and arranged at intervals.

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