A kind of large box ship main engine cylinder body combined milling pin hole accessory milling head device

Abstract

The present application belongs to the field of host cylinder milling pin hole processing, and particularly relates to a large box ship host cylinder milling pin hole accessory milling head device. The present application comprises: a tool shank body and a tool shank bending part; the tool shank body and the tool shank bending part form a bending structure, and the bending angle is 30-50 degrees; one end of the tool shank body is provided with a tool shank mounting end; the other end of the tool shank body is connected with the tool shank bending part; one end of the tool shank bending part is provided with a cutter head; the tool shank bending part is internally provided with a cutter head main shaft for driving the cutter head to rotate; the cutter head is provided with a plurality of tool clamping holes for mounting milling cutters; the tool shank bending part is provided with a cooling liquid outlet hole around the cutter head; and the tool shank body is provided with a cooling liquid inlet hole. The 30-50 degree bending structure formed by the tool shank body and the tool shank bending part avoids the influence of the casting interference area, facilitates accurate milling in complex areas, and improves the processing efficiency and processing precision.

Description

Technical Field

[0001] This invention belongs to the field of milling pin holes in main engine cylinder blocks, specifically relating to an accessory milling head device for milling pin holes in main engine cylinder blocks of large container ships. Background Technology

[0002] In the machining of large marine main engine cylinder blocks, traditional milling cutters are structurally limited and cannot meet the high-precision machining requirements of ultra-long pin holes. Taking the 9X92B cylinder block as an example, the length of the pin hole on its mating surface reaches 336mm, with an effective mating portion of 160mm. When using a manual reamer for milling, it is easily affected by the casting interference area, resulting in tool vibration, excessive surface roughness (Ra>3.2μm), and low efficiency.

[0003] Existing end mills are mostly straight shank designs, lacking rigidity and unable to avoid cast protrusions on the cylinder head face, requiring frequent toolpath adjustments and accelerating tool wear. Furthermore, the cutting edge is prone to thermal deformation during continuous machining, making it difficult to stably control dimensional tolerances within ±0.05mm. Although optimizing process parameters can partially improve machining quality, the inherent structural defects of the tool itself remain the core issue limiting efficiency and accuracy. Therefore, a new type of end mill is urgently needed to solve the problems of interference avoidance, poor rigidity, low machining accuracy and stability, and low machining efficiency. Summary of the Invention

[0004] This invention addresses the problems of low efficiency, low precision, and poor rigidity in the manual milling of connecting pin holes in the main engine cylinder block of large container ships, which are affected by casting interference. The invention proposes an accessory milling head device for milling pin holes in the main engine cylinder block of large container ships, comprising: a tool holder body and a tool holder bending section; the tool holder body and the tool holder bending section form a bending structure with a bending angle of 30° to 50°; one end of the tool holder body is provided with a tool holder mounting end; the other end of the tool holder body is connected to the tool holder bending section; one end of the tool holder bending section is provided with a cutter head; a cutter head spindle that drives the cutter head to rotate is provided inside the tool holder bending section; the cutter head is provided with several tool clamping holes for mounting milling cutters; a coolant outlet hole is provided around the cutter head on the tool holder bending section; a coolant inlet hole is provided on the tool holder body; the coolant outlet hole and the coolant inlet hole are connected by a coolant pipe provided inside the tool holder body and the tool holder bending section; the tool holder body is also provided with a circuit terminal; the circuit terminal is connected to the cutter head spindle.

[0005] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, the distance from the central axis of the tool clamping hole for mounting the milling cutter on the cutter head to the central axis of the cutter head is the same; and they are evenly distributed on the end face of the cutter head.

[0006] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, there are two cutter heads: a first cutter head and a second cutter head, which are set on two pairs of sides of the curved part of the cutter.

[0007] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, the distance from the end face of the first cutter head to the middle section of the cutter head spindle is less than the distance from the end face of the second cutter head to the middle section of the cutter head spindle.

[0008] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, both the main body of the tool holder and the curved part of the tool holder are hollow structures; the interior of the connection between the main body of the tool holder and the curved part of the tool holder is provided with radially intersecting reinforcing ribs, the thickness of which is 1 / 5 to 1 / 3 of the cross-sectional width of the main body of the tool holder, in order to improve vibration resistance and rigidity.

[0009] According to the above-described accessory milling head device for milling pin holes in the main engine cylinder block of a large container ship, the number of tool clamping holes for mounting milling cutters on the cutter head is 3-6.

[0010] According to the above-described milling head device for milling pin holes in the main engine cylinder block of a large container ship, there are 3-6 coolant outlet holes arranged around the cutter disc on the curved part of the cutter shank.

[0011] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, the coolant spray direction of the coolant outlet is at an angle of 70° to 90° with the cutter head, and the flow rate is 10 to 15 L / min.

[0012] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, the coolant is a water-based emulsion with a pH value of 7.5 to 8.5 and contains extreme pressure additives.

[0013] According to the above-described milling head device for milling pin holes in the main engine cylinder of a large container ship, a chip removal groove is provided on the end face of the cutter head, the groove depth is 2mm-6mm, and the helix angle is 20°-40°.

[0014] The beneficial effects of the present invention are as follows:

[0015] 1. The 30° to 50° bending structure formed by the tool holder body and the tool holder bending part of the present invention enhances spatial adaptability, avoids the influence of casting interference area, and facilitates precise milling in complex areas.

[0016] 2. The dual-tool head layout of the present invention: the first tool head and the second tool head, combined with the uniform distribution of tool clamping holes, support multi-angle synchronous processing, thereby improving processing efficiency and balance.

[0017] 3. The distance from the end face of the first cutter head to the middle section of the cutter head spindle is less than the distance from the end face of the second cutter head to the middle section of the cutter head spindle, which can meet the processing requirements of different pin hole depths and expand the versatility of pin hole processing.

[0018] 4. The hollow tool holder body and the internal reinforcing ribs of the tool holder bending part of the present invention reduce weight while improving vibration resistance and rigidity, ensuring machining accuracy and stability under high load.

[0019] 5. The coolant inlet of the present invention adopts multi-hole directional injection, with 3 to 6 outlet holes and a spray angle of 70° to 90°. Combined with a high flow rate of 10 to 15 L / min, water-based emulsion, pH 7.5 to 8.5 containing extreme pressure additives, it effectively reduces cutting temperature and tool wear, and extends service life.

[0020] 6. The spiral chip removal groove on the end face of the cutter head of this invention optimizes chip removal efficiency and avoids machining defects caused by chip accumulation. The overall design takes into account structural strength, heat dissipation performance and operational flexibility, and is suitable for high-precision and high-strength milling scenarios such as the main engine cylinder block of large container ships, significantly improving machining quality and production efficiency. Attached Figure Description

[0021] Figure 1 This is a front view of a schematic diagram of the structure of a milling head device for milling pin holes in the main engine cylinder of a large container ship according to the present invention.

[0022] Figure 2 This is a left view of a schematic diagram of the structure of a milling head device for milling pin holes in the main engine cylinder of a large container ship according to the present invention.

[0023] Figure 3 This is a top view of a schematic diagram of the structure of a milling head device for milling pin holes in the main engine cylinder of a large container ship according to the present invention.

[0024] In the figure: 1-tool holder body, 2-tool holder bending part, 3-tool disc, 4-tool clamping hole, 5-coolant inlet hole, 6-coolant outlet hole, 11-tool holder mounting end, 12-circuit wiring terminal, 31-first tool disc, 32-second tool disc. Detailed Implementation

[0025] Preferred Implementation

[0026] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the scope of protection of this application.

[0027] like Figures 1 to 3As shown: In this embodiment, an accessory milling head device for milling pin holes in the main engine cylinder of a large container ship includes: a tool holder body 1 and a tool holder bending part 2; the tool holder body 1 and the tool bending part 2 form a bending structure with a bending angle α of 30° to 50°; one end of the tool holder body 1 is provided with a tool holder mounting end 11; the other end of the tool holder body 1 is connected to the tool holder bending part 2; one end of the tool holder bending part 2 is provided with a cutter head 3; a cutter head spindle that drives the cutter head 3 to rotate is provided inside the tool holder bending part 2; the cutter head 3 is provided with a plurality of tool clamping holes 4 for mounting milling cutters; a coolant outlet hole 6 is provided around the cutter head 3 on the tool holder bending part 2; a coolant inlet hole 5 is provided on the tool holder body 1; the coolant outlet hole 6 and the coolant inlet hole 5 are connected by a coolant pipe provided inside the tool holder body 1 and the tool holder bending part 2; the tool holder body 1 is also provided with a circuit terminal 12; the circuit terminal 12 is connected to the cutter head spindle.

[0028] The distance from the central axis of the tool clamping hole 4 for mounting the milling cutter on the cutter head 3 to the central axis of the cutter head 3 is the same; they are evenly distributed on the end face of the cutter head 3.

[0029] There are two cutter heads 3: a first cutter head 31 and a second cutter head 32, which are located on two pairs of sides of the curved part of the cutter head 2.

[0030] The distance from the end face of the first cutter head 31 to the mid-section of the cutter head spindle is less than the distance from the end face of the second cutter head 32 to the mid-section of the cutter head spindle.

[0031] Both the handle body 1 and the handle bending part 2 are hollow structures; the interior of the joint between the handle body 1 and the handle bending part 2 is provided with radially intersecting reinforcing ribs, the thickness of which is 1 / 5 to 1 / 3 of the cross-sectional width of the handle body 1, which is used to improve vibration resistance and rigidity.

[0032] The cutter head 3 has 3-6 tool clamping holes 4 for mounting milling cutters.

[0033] There are 3-6 coolant outlet holes 5 arranged around the cutter disc 3 on the curved part 2 of the tool holder.

[0034] The coolant spray direction of the coolant outlet 6 is at an angle of 70° to 90° with the cutter head 3, and the flow rate is 10 to 15 L / min.

[0035] The coolant is a water-based emulsion with a pH of 7.5–8.5 and contains extreme pressure additives.

[0036] Chip removal grooves are provided on the end face of the cutter head 3. The depth of the chip removal grooves is 2mm-6mm and the helix angle is 20°-40°. Detailed Implementation

[0038] Step 1: Preparation before processing

[0039] The milling cutter is mounted to the first cutter head 31 and the second cutter head 32 via a 7:24 taper shank, ensuring that the radial runout of the first cutter head 31 and the second cutter head 32 is ≤0.005mm.

[0040] Workpiece fixing and positioning: The 9X92B cylinder block is hoisted onto the CNC gantry milling machine table and clamped using hydraulic clamps to ensure that the cylinder block mating surface is parallel to the machine tool coordinate system and that the flatness error is minimized.

[0041] ≤0.05mm / m. Use a laser tool setter to calibrate the initial position of the milling cutter, with a positioning accuracy of ±0.005mm.

[0042] Step 2: Setting Processing Parameters

[0043] Spindle speed and feed settings: Adjust the spindle speed of the cutter head to 1000 r / min, the feed rate to 0.2 mm / r, and the depth of cut to 0.5 mm.

[0044] Cooling system startup: Open the integrated coolant channel, inject water-based emulsion with pH 8.0 at a flow rate of 12L / min, and spray at an 80° angle to the cutting edge of the milling cutter to ensure sufficient cooling of the root of the milling cutter.

[0045] Step 3: Rough machining of pin holes

[0046] Path planning and trial cut: Based on the cylinder block pin hole position, the cutting tool is fed using a helical interpolation method. The milling cutter performs trial cuts along the preset path to check cutting vibration and chip removal. Cutting parameters are adjusted to ensure the chip grooves (2mm depth, 30° helix angle) are unobstructed and to prevent chip accumulation.

[0047] Layered milling: Roughing is completed in 3 passes, with a cutting depth of 5mm for each layer, leaving a finishing allowance of 0.1mm. The tool temperature is monitored in real time during the machining process to ensure it does not exceed 80℃.

[0048] Step 4: Finishing the pin holes

[0049] Precision Correction: Switch to finishing mode, increase the spindle speed to 1200 r / min, reduce the feed rate to 0.1 mm / r, and achieve a single-layer depth of cut of 0.2 mm. Utilize the high wear resistance of the TiAlN coated end mill cutting edge to continuously machine to the final dimensions.

[0050] Surface quality control: Thermal deformation is reduced by directional coolant spraying to ensure that the surface roughness Ra of the pin hole is ≤1.6μm, the diameter tolerance is ±0.02mm, and the straightness error is ≤0.03mm.

[0051] Step 5: Quality Inspection and Correction

[0052] Online inspection: After machining, use a coordinate measuring machine to scan the inner wall of the pin hole to check the diameter, roundness and position. The pass rate must be ≥99%.

[0053] Local correction: If local deviations are found, such as diameter deviation > 0.02mm, use the same milling cutter to perform micro-milling, with a correction amount ≤ 0.01mm, to avoid secondary clamping errors.

[0054] Key operational points:

[0055] Avoiding interference areas: By utilizing the curved structure formed by the tool holder body (1) and the curved part of the tool (2), the casting protrusion is automatically avoided when machining the pin hole near the cylinder head face, without the need to adjust the workpiece angle.

[0056] Tool life management: Check the wear of the milling cutter edge after machining 5 pin holes. If the coating peels off or the passivation width is >0.02mm, replace the insert immediately.

[0057] Implementation results:

[0058] Through the above steps, the machining time for a single 336mm long pin hole is reduced from 8 hours in the traditional process to 4 hours, the dimensional qualification rate is increased from 85% to 99.5%, and the tool life reaches 120 hole cycles, which is 50% higher than that of traditional milling cutters, fully meeting the high-efficiency and high-precision machining requirements of the 9X92B cylinder block.

[0059] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A milling head device for milling pin holes in the main engine cylinder block of a large container ship, characterized in that, include: The tool holder body (1) and the tool holder bending part (2) form a bending structure with a bending angle of 30°~50°; one end of the tool holder body (1) is provided with a tool holder mounting end (11); the other end of the tool holder body (1) is connected to the tool holder bending part (2); one end of the tool holder bending part (2) is provided with a cutter disc (3); the inside of the tool holder bending part (2) is provided with a cutter disc spindle that drives the cutter disc (3) to rotate; the cutter disc (3) is provided with a tool holder body (1) and a tool holder bending part (2) A number of tool clamping holes (4) for mounting milling cutters; a coolant outlet hole (6) is provided around the cutter head (3) on the curved part (2) of the tool holder; a coolant inlet hole (5) is provided on the main body (1) of the tool holder; the coolant outlet hole (6) and the coolant inlet hole (5) are connected by a coolant pipe provided inside the main body (1) and the curved part (2) of the tool holder; a circuit terminal (12) is also provided on the main body (1); the circuit terminal (12) is connected to the cutter head spindle.

2. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 1, characterized in that, The distance from the central axis of the tool clamping hole (4) for mounting the milling cutter on the cutter head (3) to the central axis of the cutter head (3) is the same; they are evenly distributed on the end face of the cutter head (3).

3. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 2, characterized in that, There are two cutter heads (3): a first cutter head (31) and a second cutter head (32), which are set on two pairs of sides of the curved part of the cutter (2).

4. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 3, characterized in that, The distance from the end face of the first cutter head (31) to the middle section of the cutter head spindle is less than the distance from the end face of the second cutter head (32) to the middle section of the cutter head spindle.

5. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 4, characterized in that, Both the handle body (1) and the handle bending part (2) are hollow structures; the interior of the handle body (1) and the handle bending part (2) is provided with radially intersecting reinforcing ribs, the thickness of which is 1 / 5 to 1 / 3 of the cross-sectional width of the handle body (1), which is used to improve vibration resistance and rigidity.

6. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 5, characterized in that, The number of tool clamping holes (4) for mounting milling cutters on the cutter head (3) is 3-6.

7. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 6, characterized in that, There are 3-6 coolant outlet holes (6) arranged around the cutter disc (3) on the curved part (2) of the tool holder.

8. The milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 7, characterized in that, The coolant spray direction of the coolant outlet (6) is at an angle of 70°~90° with the cutter head (3), and the flow rate is 10~15L / min.

9. A milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 8, characterized in that, The coolant is a water-based emulsion with a pH of 7.5 to 8.5 and contains extreme pressure additives.

10. A milling head device for milling pin holes in the main engine cylinder block of a large container ship according to claim 9, characterized in that, The chip removal groove is provided on the end face of the cutter head (3), with a groove depth of 2mm-6mm and a helix angle of 20°-40°.

Images