Engine crossed oil duct deburring cutter and design method

Abstract

The invention provides an engine cross oil duct deburring tool and a design method, the engine cross oil duct deburring tool comprises a tool body and a tool bit, the tool bit is connected to one end of the tool body, the tool bit is provided with two oppositely-arranged cutting edges, a cutting groove is formed between the cutting edges, at least one flushing hole is formed in the cutting groove, and the flushing hole is communicated with the tool body. An inner cooling hole is formed in the cutter body and communicated with the flushing hole. Compared with a deburring brush, the cutter is additionally provided with the inner cooling hole and the flushing hole, so that the cutting edge of the cutter is promoted to annularly cut around the hole wall, and meanwhile, the removed burrs can be flushed to the front end until the burrs are flushed out from an oil duct outlet at the other end, so that burr residues are avoided, the workpiece cleaning difficulty is reduced, and the cleanliness of the cylinder body is further improved.

Description

Technical Field

[0001] The invention belongs to the technical field of engine processing, and in particular relates to a deburring tool for an engine cross oil passage and a design method thereof. Background Art

[0002] When cutting castings, burrs and flanging are easily generated at the intersection of two surfaces, especially the T-shaped orifice of the cross hole, which is very likely to generate burrs that flanging toward the hole wall. In the complex internal oil circuit of the cylinder body, there are multiple deep cross oil holes. The burrs generated during the processing are generally removed by repeatedly brushing with a wire brush.

[0003] Due to the strong rigidity of cast iron, wire brushes are often not thorough enough in removing burrs, and the remaining burrs will still seriously affect the cleanliness of the oil channel. At the same time, wire brushes are prone to falling off and getting stuck in the oil channel after a certain service life. Therefore, when the engine piston is working, there is a risk of residual burrs and wires falling off, which will lead to serious consequences such as cylinder pulling, crankshaft locking, and scratches on the piston hole wall. In addition, the use of dedicated deburring brushes requires the design of a special machine on the roller table, which involves a large production line modification and has poor universality. Summary of the invention

[0004] The purpose of the present invention is to provide an engine cross oil channel deburring tool and design method, aiming to solve the problem of burr residue, brush wire falling and jamming, which affects the cleanliness of oil channels / various cast iron parts holes.

[0005] The present invention is implemented as follows: an engine cross oil channel deburring tool includes a tool body and a tool head, wherein the tool head is connected to one end of the tool body, the tool head is provided with two oppositely arranged cutting blades, a cutting groove is provided between the cutting blades, at least one flushing hole is provided in the cutting groove, an internal cooling hole is provided inside the tool body, and the internal cooling hole is connected to the flushing hole.

[0006] A further technical solution of the present invention is that the coolant of the flushing hole is sprayed in a direction toward the hole wall and the cutting edge of the cutting blade.

[0007] A further technical solution of the present invention is: a chip removal groove is provided along the surface of the tool body, and the chip removal groove is communicated with the cutting groove.

[0008] A further technical solution of the present invention is that the included angle between the flushing hole and the inner cooling hole is 45°.

[0009] A further technical solution of the present invention is that the included angle between the flushing hole and the inner cooling hole is 60°.

[0010] A further technical solution of the present invention is that the diameter of the inner cooling hole is less than or equal to 0.2 mm.

[0011] A further technical solution of the present invention is that the single-sided tool clearance between the cutting edge and the hole wall is less than or equal to 0.05 mm.

[0012] A further technical solution of the present invention is that the cutter head and the cutter body are connected by welding.

[0013] The present invention also provides a design method for a deburring tool for an engine cross oil channel. According to the design standard of the tool for processing the aperture of the main oil channel of the product, the maximum cutting diameter of the deburring tool is designed. The deburring tool is offset during rotation, so that the tool is circularly cut to remove burrs in the hole. The coolant impact reaction force and the speed feed parameters during the tool rotation process are designed to determine the tool rotation offset correction coefficient. The offset distance is related to the speed, cutting force and acting force during the tool processing process. The calculation formula of the offset is:

[0014] a=Rk 1 , k 1 =k F +k S +k 0

[0015] The offset correction factor k 1 It is determined by the rotation speed, cutting force and action force. In the deburring process, the cutting amount is very small and the cutting force can be ignored. 1 The influence of can be ignored, so k 0 Take 0, offset coefficient k S Depends on the machining speed, tool diameter and tool aspect ratio, k F The value of depends on the magnitude of the radial external force on the tool;

[0016] In the process of cutting fluid spraying, according to the principle of constant total flow in hydraulics, there is a spray reaction force in the flushing hole. The internal cooling spray reaction force on the tool can be calculated using the fluid momentum equation:

[0017]

[0018] During the processing, the equipment fluid supply system is stable, so the momentum correction coefficient α can be taken as 1. From the perspective of projection, the reaction force received by the flushing hole when spraying in a horizontal position is:

[0019]

[0020] According to the continuity equation of the fluid, we can get:

[0021] v 1 A 1 =v 2 A 2

[0022] The diameter of the tool internal coolant hole port and the orifice is consistent, that is, v 1 =v 2 ,q v The flow rate is determined by the velocity in the equipment supply pipe and the cross-sectional area of ​​the internal cooling hole:

[0023] q v =3600πr 2 V

[0024] Commonly used cutting fluid density on machine tools ρ = 1100Kg / m 3 , the pressure is P = 10bar, the radius of the design tool inner coolant hole is rmm, then the water speed calculation when the inner coolant hole sprays cutting fluid is:

[0025]

[0026] That is, the flow velocity V in the inner coolant hole. Combining the above formula, the injection reaction force on the inner coolant hole of the tool is:

[0027]

[0028] If the flushing hole of the cutting edge is designed with different liquid outlet angles, the tool will be subjected to the resultant axial force of the jet reaction force:

[0029] F r =F 1 cosα 1 -F 2 cosα 2

[0030] At the same time, the time that the liquid column ejected from the orifice hits the inner wall of the hole is very short. The force of the liquid column on the tool can be calculated using Newton's second law:

[0031] F 3 =Δm*Δv / Δt

[0032] Using the fluid mechanics formula, the coolant contact time of the hole wall can be calculated:

[0033]

[0034] Taking the cross section of the flushing hole as the reference plane, the time from the coolant spraying out at the hole mouth to the coolant contacting the hole wall is Calculate Δt, and then the instantaneous reaction force of the inner wall on the liquid column is:

[0035] F 3 =Δm*Δv / Δt=ρSΔLΔv / Δt

[0036] α 1 With α 2 is the angle between the flushing hole and the internal cooling hole, and F is calculated. 3 , and then calculate the radial force Fr , then corresponding to the empirical coefficient, the radial force F is obtained r The offset coefficient k f , and then get the offset correction coefficient k 1 The maximum possible value is calculated according to the limit state, and the deburring offset of the tool size is obtained as a=Rk 1 Therefore, the designed cutting diameter of the tool is 2×(R+a), which is the orbital diameter of the deburring tool.

[0037] The beneficial effects of the present invention are as follows: the tool has the additional inner cooling hole and flushing hole compared to the deburring brush, which can facilitate the cutting edge of the tool to cut around the hole wall while flushing the removed burrs to the front end until they are flushed out from the oil channel outlet at the other end, thereby avoiding burr residue, reducing the difficulty of cleaning the workpiece, and further improving the cleanliness of the cylinder body. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 is an overall diagram of the tool of the present invention;

[0039] Figure 2 is a side view of the tool of the present invention;

[0040] Figure 3 It is a schematic diagram of the positional relationship between the inner cooling hole and the flushing hole in the tool of the present invention.

[0041] Reference numerals: 1 - tool body, 2 - tool head, 3 - cutting tool edge, 4 - cutting groove, 5 - flushing hole, 6 - chip removal groove, 7 - internal cooling hole. DETAILED DESCRIPTION

[0042] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be noted that the words "front", "rear", "left", "right", "upper" and "lower" used in the following description refer to directions in the accompanying drawings, and the words "bottom surface" and "top surface", "inside" and "outside" refer to directions toward or away from the geometric center of a specific component, respectively.

[0043] Figure 1-3 An engine cross oil channel deburring tool provided by the present invention is shown, comprising a tool body 1 and a tool head 2, wherein the tool head 2 is connected to one end of the tool body 1, and the tool head 2 is provided with two oppositely arranged cutting edges 3, a cutting groove 4 is provided between the cutting edges 3, and at least one flushing hole 5 is provided in the cutting groove 4, and an internal cooling hole 7 is provided inside the tool body 1, and the internal cooling hole 7 is connected to the flushing hole 5.

[0044] Preferably, the coolant spraying direction of the flushing hole 5 is toward the hole wall and the cutting edge of the cutting blade 3 .

[0045] Preferably, a chip removal groove 6 is provided along the surface of the tool body 1 , and the chip removal groove 6 is communicated with the cutting groove 4 .

[0046] Preferably, the included angle between the flushing hole 5 and the inner cooling hole 7 is 45°.

[0047] Preferably, the included angle between the flushing hole 5 and the inner cooling hole 7 is 60°.

[0048] Preferably, the diameter of the inner cooling hole 7 is less than or equal to 0.2 mm.

[0049] Preferably, the single-sided tool clearance between the cutting edge 3 and the hole wall is less than or equal to 0.05 mm.

[0050] Preferably, the cutter head 2 and the cutter body 1 are connected by welding.

[0051] The present invention also provides a design method for a deburring tool for an engine cross oil channel. According to the design standard of the tool for processing the aperture of the main oil channel of the product, the maximum cutting diameter of the deburring tool is designed. The deburring tool is offset during rotation, so that the tool is circularly cut to remove burrs in the hole. The coolant impact reaction force and the speed feed parameters during the tool rotation process are designed to determine the tool rotation offset correction coefficient. The offset distance is related to the speed, cutting force and acting force during the tool processing process. The calculation formula of the offset is:

[0052] a=Rk 1 , k 1 =k F +k S +k 0

[0053] The offset correction factor k 1 It is determined by the rotation speed, cutting force and action force. In the deburring process, the cutting amount is very small and the cutting force can be ignored. 1 The influence of can be ignored, so k 0 Take 0, offset coefficient k S Depends on the machining speed, tool diameter and tool aspect ratio, k F The value of depends on the magnitude of the radial external force on the tool;

[0054] In the process of cutting fluid spraying, according to the hydraulic constant total flow principle, there is a spray reaction force in the flushing hole 5. The internal cooling spray reaction force on the tool can be calculated using the fluid momentum equation:

[0055]

[0056] During the processing, the equipment liquid supply system is stable, so the momentum correction coefficient α can be taken as 1. From the perspective of projection, the reaction force received by the flushing hole 5 when spraying in the horizontal position is:

[0057]

[0058] According to the continuity equation of the fluid, we can get:

[0059] v 1 A 1 =v 2 A 2

[0060] The diameter of the tool internal coolant hole 7 port and the orifice is consistent, that is, v 1 =v 2 ,q v The flow rate is determined by the velocity in the equipment supply pipe and the cross-sectional area of ​​the internal cooling hole 7:

[0061] q v =3600πr 2 V

[0062] Commonly used cutting fluid density on machine tools ρ = 1100Kg / m 3 , the pressure is P = 10 bar, the radius of the design tool inner coolant hole 7 is r mm, then the water speed calculation when the inner coolant hole 7 sprays cutting fluid is:

[0063]

[0064] That is, the flow velocity V in the inner coolant hole 7. Combining the above formula, the injection reaction force on the inner coolant hole 7 of the tool is:

[0065]

[0066] If the flushing hole 5 of the cutting blade 3 is designed with different liquid outlet angles, the tool will be subjected to the resultant axial force of the jet reaction force:

[0067] F r =F 1 cosα 1 -F 2 cosα 2

[0068] At the same time, the time that the liquid column ejected from the orifice hits the inner wall of the hole is very short. The force of the liquid column on the tool can be calculated using Newton's second law:

[0069] F 3 =Δm*Δv / Δt

[0070] Using the fluid mechanics formula, the coolant contact time of the hole wall can be calculated:

[0071]

[0072] Taking the cross section of flushing hole 5 as the reference plane, the time from the spraying of coolant at the hole mouth to the coolant contacting the hole wall is Calculate Δt, and then the instantaneous reaction force of the inner wall on the liquid column is:

[0073] F 3 =Δm*Δv / Δt=ρSΔLΔv / Δt

[0074] α 1 With α 2 is the angle between flushing hole 5 and internal cooling hole 7, and F is calculated. 3 , and then calculate the radial force F r , then corresponding to the empirical coefficient, the radial force F is obtained r The offset coefficient k f , and then get the offset correction coefficient k 1 The maximum possible value is calculated according to the limit state, and the deburring offset of the tool size is obtained as a=Rk 1 Therefore, the designed cutting diameter of the tool is 2×(R+a), which is the orbital diameter of the deburring tool.

[0075] The present invention provides a deburring tool for engine cross oil passages. By analyzing the processing technology, the deburring scheme is optimized for the burr direction of the cross hole in the oil passage / parts, and the deburring method using a wire brush is eliminated, thereby avoiding the risk of the brush wire falling. The newly designed deburring tool is used, and the carbide cutting edge can completely remove the burrs. At the same time, only this processing content needs to be added to the CNC machining center, eliminating the cost and risk of production line transformation.

[0076] This special deburring tool design has been applied to the OP110 process of S15DHE engine cylinder line in the machining workshop of Liuzhou Saike Technology Development Co., Ltd., and the deburring effect is remarkable in actual production. The tool design process is as follows:

[0077] (1) The design considers using eccentric force on the tool so that the tool edge revolves around the inner wall of the cross oil channel hole during processing to remove burrs.

[0078] (2) Analysis of the force applied to the tool during machining: During normal machining, the tool is subject to the reaction force of the cutting fluid flushing outward from the inner coolant tube, as well as the eddy current lateral force generated by the cutting fluid rotating when the tool rotates (which can be ignored because the main oil channel is a through hole). At this time, the tool subjected to the reaction force of the fluid will rotate around the turret spindle as the axis, while performing orbital motion, that is, cutting the burrs facing the main oil channel along the hole wall.

[0079] The force analysis of the tool design process is introduced below using an embodiment.

[0080] According to the commonly used cutting fluid density on machine tools, ρ≈1100Kg / m 3 , the pressure is P = 10 bar, and the diameter of the tool inner coolant hole 7 is designed to be 0.2 mm. When the inner coolant hole 7 sprays the cutting fluid, the water velocity is According to Newton's second law, F = Δm*Δv / Δt, the time for the cutting fluid to be ejected from the orifice is very short. According to the fluid mechanics formula, For the convenience of calculation, the cross section of flushing hole 5 is used as the reference plane. The time from the spraying of coolant at the hole mouth to the coolant contacting the hole wall is The calculation results show that Δt = 0.0012 × 10 -3 S, then the instantaneous reaction force exerted by the inner wall on the liquid column is It can be ignored. In the process of cutting fluid ejection, according to the hydraulic constant total flow principle, the liquid has an ejection reaction force on the flushing hole 5. The ejection reaction force is based on the momentum equation of the constant total flow: During the processing, the equipment fluid supply system is relatively stable, so the momentum correction coefficient α can be approximately taken as 1. From the perspective of projection, the reaction force on the cutting fluid orifice when it is sprayed in a horizontal position is: According to the continuity equation of the fluid, we can get: 1 A 1 =v 2 A 2 , the diameter of the tool internal coolant hole 7 port and the orifice is consistent, that is, v 1 =v 2 =42.68m / s. Since the supply pressure is 10bar, q v It can be calculated as 0.005m 3 / h, then the injection reaction force F=234.74N is calculated.

[0081] During the rotation of the tool, a rotation offset will be generated. The offset distance is related to the tool speed, cutting force, and force during the machining process. The calculation formula for the offset is: a = Rk 1 , where the offset correction factor k 1 =k F +k S +k 0 According to the experience of tool cutting manual, at a speed of 2000-3000 (r·min -1 ) below, diameter 12. The offset coefficient of carbide tools with an aspect ratio of 15-25 is 2×10 -3 If the cutting fluid jet reaction force factor is added to this design, the trajectory deviation coefficient will be higher when the tool rotates. The resultant force F in the axial direction of the tool isr =F 1 cosα 1 -F 2 cosα 2 , take α 1 =45°, α 2 =60°, the radial force F is calculated r =48.62N.

[0082] Then the corresponding empirical coefficient, radial force F r The offset coefficient k f =12×10 -3 , so the offset correction coefficient k 1 Maximum 14×10 -3 , according to the limit state calculation, the tool size Deburring offset a = Rk 1 =5.95×14×10 -3 =0.083mm. Therefore, the designed cutting diameter of the tool is 2×(R+a)=12.067mm, which is the deburring orbital diameter.

[0083] The tool provided by the present invention has the additional inner cooling hole 7 and flushing hole 5 compared to the deburring brush. While promoting the cutting edge of the tool to cut around the hole wall, the removed burrs can be flushed to the front end until they are flushed out from the oil channel outlet at the other end, thereby avoiding burr residue, reducing the difficulty of cleaning the workpiece, and further improving the cleanliness of the cylinder body.

[0084] The special tool design has been applied in the machining factory of Liuzhou Saike Technology Development Co., Ltd., and is used for the main oil channel deburring station in the production of cylinder parts. Production tracking has proved that the cleanliness level of the cylinder oil channel has been significantly improved, effectively solving the problem of difficult burr removal during the processing of complex oil channel cross holes inside the cylinder, further improving the cleanliness of the cylinder, and avoiding serious consequences such as cylinder pulling, crankshaft locking, and piston hole wall scratches caused by the residual burrs falling when the engine piston is working. The tool design and manufacturing is relatively simple, and the production cost can be further reduced in the future. The tool edge is only involved in burr removal. For the carbide cutter head 2, the cutting wear is extremely small, and the tool life can be further improved. The tool bar is made of high-speed steel, which reduces the risk of alloy collision during processing and greatly improves the universality of the tool.

[0085] Since the deburring method using a wire brush has been eliminated, the risk of product quality problems caused by the falling of the brush wire is eliminated when the product is working. Using a newly designed special deburring tool, the burrs and flanging generated by the oil channel / internal cross hole can be completely removed under the cutting of the carbide blade. At the same time, it is easy to install and use, and there is no need to design production line tooling and fixtures, etc., which simplifies the layout of the production line. The designed tool edge is simple and efficient, without complex edge distribution, which greatly saves the cost of tool manufacturing. While having a long service life, burrs and flanging are efficiently and thoroughly removed, and the cleanliness FTQ of the oil channel / internal cross hole of the part is improved. The cycle time is not large, which is particularly in line with the requirements of mass production. At the same time, the tool optimized by this solution has made adjustments to the direction of the internal coolant outlet, and can flush the removed burrs to the hole position on the premise of completely removing burrs and flanging, which is convenient for cleaning by the cleaning machine.

[0086] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions and improvements made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A deburring tool for engine cross oil passages, characterized in that: It includes a tool body and a tool head, wherein the tool head is connected to one end of the tool body, the tool head is provided with two oppositely arranged cutting edges, a cutting groove is provided between the cutting edges, at least one flushing hole is provided in the cutting groove, and an internal cooling hole is provided inside the tool body, and the internal cooling hole is connected to the flushing hole.

2. The engine cross oil channel deburring tool according to claim 1, characterized in that: The coolant of the flushing hole is sprayed in a direction toward the hole wall and the cutting edge of the cutting blade.

3. The engine cross oil channel deburring tool according to claim 1, characterized in that: A chip removal groove is provided along the surface of the tool body, and the chip removal groove is communicated with the cutting groove.

4. The engine cross oil channel deburring tool according to claim 1, characterized in that: The included angle between the flushing hole and the inner cooling hole is 45°.

5. The engine cross oil channel deburring tool according to claim 1, characterized in that: The included angle between the flushing hole and the inner cooling hole is 60°.

6. The engine cross oil channel deburring tool according to claim 1, characterized in that: The diameter of the inner cooling hole is less than or equal to 0.2 mm.

7. The engine cross oil channel deburring tool according to claim 1, characterized in that: The single-side tool clearance between the cutting edge and the hole wall is less than or equal to 0.05 mm.

8. The engine cross oil channel deburring tool according to claim 1, characterized in that: The cutter head and the cutter body are connected by welding.

9. A method for designing a deburring tool for an engine cross oil passage according to any one of claims 1 to 8, characterized in that: According to the design standard of the tool for processing the main oil channel aperture of the product, the maximum cutting diameter of the deburring tool is designed. The deburring tool will be offset during the rotation process, so that the tool will cut the burrs in the hole. The coolant impact reaction force and speed feed parameters during the tool rotation process are designed to determine the tool rotation offset correction coefficient. The offset distance is related to the speed, cutting force and force during the tool processing process. The calculation formula for the offset is: a=Rk1,k1=k F +k S +k0 The offset correction coefficient k1 is determined by the rotation speed, cutting force and action force. In the deburring process, the cutting amount is very small, the cutting force can be ignored, and its influence on k1 can be ignored, so k0 is 0, and the offset coefficient k S Depends on the machining speed, tool diameter and tool aspect ratio, k F The value of depends on the magnitude of the radial external force on the tool; In the process of cutting fluid spraying, according to the principle of constant total flow in hydraulics, there is a spray reaction force in the flushing hole. The internal cooling spray reaction force on the tool can be calculated using the fluid momentum equation: During the processing, the equipment fluid supply system is stable, so the momentum correction coefficient α can be taken as 1. From the perspective of projection, the reaction force received by the flushing hole when spraying in a horizontal position is: According to the continuity equation of the fluid, we can get: v1A1=v2A2 The diameter of the tool internal coolant hole port and the orifice is consistent, that is, v1 = v2, q v The flow rate is determined by the velocity in the equipment supply pipe and the cross-sectional area of ​​the internal cooling hole: q v =3600πr 2 V Commonly used cutting fluid density on machine tools ρ = 1100Kg / m 3 , the pressure is P = 10bar, the radius of the design tool inner coolant hole is rmm, then the water speed calculation when the inner coolant hole sprays cutting fluid is: That is, the flow velocity V in the inner coolant hole. Combining the above formula, the injection reaction force on the inner coolant hole of the tool is: If the flushing hole of the cutting edge is designed with different liquid outlet angles, the tool will be subjected to the resultant axial force of the jet reaction force: F r =F1cosα1-F2cosα2 At the same time, the time that the liquid column ejected from the orifice hits the inner wall of the hole is very short. The force of the liquid column on the tool can be calculated using Newton's second law: F3=Δm*Δv / Δt Using the fluid mechanics formula, the coolant contact time of the hole wall can be calculated: Taking the cross section of the flushing hole as the reference plane, the time from the coolant spraying out at the hole mouth to the coolant contacting the hole wall is Calculate Δt, and then the instantaneous reaction force of the inner wall on the liquid column is: F3=Δm*Δv / Δt=ρSΔLΔv / Δt α1 and α2 are the angles between the flushing hole and the internal cooling hole. F3 is calculated, and then the radial force F is calculated. r , then corresponding to the empirical coefficient, the radial force F is obtained r The offset coefficient k f , and then the maximum possible value of the offset correction coefficient k1 is obtained. According to the limit state measurement, the deburring offset a=Rk1 of the tool size is obtained. Therefore, the designed cutting diameter of the tool is 2×(R+a), which is the orbital diameter of the deburring tool.

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