A method for machining superimposed deep holes with different diameters

Abstract

The present invention relates to the technical field of deep hole machining, and specifically to a method for machining superimposed deep holes of varying diameters. The method comprises determining a tool; determining a machining sequence based on the determined tool; sequentially machining a φ11mm shallow hole, a φ22mm countersink, an M6 bottom hole, a φ5mm deep hole, a φ7mm deep hole, and an M6 threaded hole on a bearing housing based on the machining sequence; and performing a gear and precision inspection on the machined bearing housing. The present invention avoids tool vibration and offset during deep hole machining by determining the hole machining sequence and rationally selecting a tool. This method addresses the problem of eccentricity in deep holes caused by existing deep hole machining methods during drilling.

Description

Technical Field

[0001] The present invention relates to the technical field of deep hole processing, and in particular to a method for processing deep holes stacked with different diameters. Background Art

[0002] The bearing housing, also known as the intermediate housing, is a critical component of a supercharger. It serves the vital functions of mounting and securing the bearing system, positioning the rotor, providing oil inlet and return channels for the bearing system, and mounting and connecting all components of the turbocharger's turbine and turbine ends. The bearing housing is a complex structure with holes of varying orientations, diameters, and depths.

[0003] The existing method for processing deep holes is as follows: first use a φ20 alloy milling cutter to process a φ22mm hole, and then use ordinary twist drills to complete the processing of φ5mm, φ7mm, and φ11mm holes in sequence. Among them, the φ5mm and φ7mm holes are calculated according to the deep hole L / D>5 method (L represents the hole depth and D represents the hole diameter), and are both deep holes.

[0004] This method of processing superimposed deep holes can solve the problem of hole chamfering. However, in the process of processing deep holes, the larger the ratio of hole depth to hole diameter, the thinner the tool bar is, the poorer the rigidity is, and the easier it is to vibrate during drilling, which can make the drill bit more likely to shift, resulting in eccentricity in the deep hole. As a result, the quality of the processed hole cannot be guaranteed and cannot meet the design technical requirements. Summary of the Invention

[0005] The purpose of the present invention is to provide a method for machining deep holes with different diameters, aiming to solve the problem that the existing deep hole machining method may cause eccentricity in the deep holes during the drilling process.

[0006] To achieve the above object, the present invention provides a method for machining superimposed deep holes of different diameters, which is used to machine a bearing shell having a φ11 mm shallow hole, a φ22 mm countersunk hole, an M6 bottom hole, a φ5 mm deep hole, a φ7 mm deep hole, and an M6 threaded hole, comprising the following steps:

[0007] Determine the tool;

[0008] Determine the machining sequence based on the determined tool;

[0009] Based on the processing sequence, the bearing shell is processed in sequence: φ11mm shallow hole processing, φ22mm countersink processing, M6 bottom hole processing and φ5mm deep hole processing, φ7mm deep hole processing and M6 threaded hole processing;

[0010] The bearing shell after processing is subjected to gear and precision inspection.

[0011] Wherein, the determining of the tool comprises:

[0012] Use φ22mm alloy hard milling cutter with pocket cutter filling method for milling, use φ11mm alloy hard drill for drilling, and use ordinary twist drill and tap for φ7mm and M6 to complete drilling and tapping.

[0013] The processing sequence is: first use a φ11mm alloy drill to process a φ11mm hole, then use a φ20 alloy milling cutter to process a φ22mm hole, and finally complete the processing of two deep holes of φ5mm and φ7mm in sequence.

[0014] The φ11mm shallow hole processing includes:

[0015] First, use a center drill bit to drill a 3mm deep center hole, and then use a φ11mm alloy hard drill bit to drill a φ11mm hole, with a speed of 800r / min, a feed of 60mm / min, and a drilling depth of 34mm.

[0016] The φ22mm countersink processing includes:

[0017] A φ20mm alloy hard end mill uses a rotation speed of 800r / min, a feed of 80mm / min, a cutting depth of 2mm, and a round cutter compensation method to complete milling a countersink with a diameter of 22mm and a depth of 16mm.

[0018] The M6 ​​bottom hole and φ5mm deep hole processing include:

[0019] First, process a φ5mm deep hole. The φ5mm drill bit drills at the pre-drilled center hole position. The φ5mm and φ7mm deep holes use the same positioning center hole to directly ensure that the φ11mm, φ7mm, and φ5mm holes are concentric. The φ5mm drill bit uses a speed of 800r / min, a feed of 30mm / min, and a cutting depth of 3mm to complete the deep hole drilling of the M6 ​​bottom hole with a diameter of 5mm and a depth of 60mm.

[0020] The φ7mm deep hole processing includes:

[0021] The φ7mm drill bit uses a rotation speed of 760r / min, a feed of 60mm / min, and a cutting depth of 3mm to complete deep hole drilling with a diameter of 7mm and a depth of 45mm.

[0022] The M6 ​​threaded hole processing includes:

[0023] Calculate the feed rate based on the pitch and speed;

[0024] The M6 ​​tap uses a rotation speed of 150 r / min and, based on the feed rate, completes the M6 ​​threaded hole machining.

[0025] The present invention provides a method for machining overlapping deep holes of varying diameters. The method involves determining a tool; determining a machining sequence based on the determined tool; and sequentially machining a φ11mm shallow hole, a φ22mm countersink, an M6 bottom hole, a φ5mm deep hole, a φ7mm deep hole, and an M6 threaded hole on a bearing housing based on the machining sequence. The bearing housing is then subjected to a gear and precision inspection. By determining the drilling sequence and selecting the appropriate tool, the present invention avoids tool vibration and offset during deep hole machining. This method addresses the problem of eccentricity in deep holes caused by existing deep hole machining methods. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0027] Figure 1 This is a cross-sectional structural diagram of the bearing shell.

[0028] Figure 2 It is a superimposed deep hole structure diagram.

[0029] Figure 3 This is a schematic diagram of a φ11mm shallow hole.

[0030] Figure 4 This is a schematic diagram of a φ22mm countersunk hole.

[0031] Figure 5 This is a schematic diagram of a φ5mm deep hole.

[0032] Figure 6 This is a schematic diagram of a φ7mm deep hole.

[0033] Figure 7 This is a schematic diagram of an M6 threaded hole.

[0034] Figure 8 This is a flow chart of a method for machining superimposed deep holes of different diameters provided by the present invention. DETAILED DESCRIPTION

[0035] The following describes embodiments of the present invention in detail, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, and are not to be construed as limiting the present invention.

[0036] See also Figures 1 to 8The present invention provides a method for machining deep holes with different diameters, which is used for machining a bearing shell having a φ11 mm shallow hole, a φ22 mm countersunk hole, an M6 bottom hole, a φ5 mm deep hole, a φ7 mm deep hole and an M6 threaded hole, comprising the following steps:

[0037] S1 determines the tool;

[0038] Specifically, according to the requirement of 1.6 roughness at the bottom of φ22mm countersunk hole, φ22mm alloy hard milling cutter is selected to use pocket cutter compensation method for milling. The tolerance requirement of φ11mm shallow hole is ±0.1mm and the side roughness is 1.6. φ11mm alloy hard drill is selected for drilling. Alloy drill is more rigid than ordinary twist drill and has better drilling stability. Ordinary twist drill and tap are used to complete drilling and tapping of φ7mm and M6.

[0039] S2 determines the processing sequence based on the determined tool;

[0040] Specifically, the processing sequence is: first use a φ11mm alloy drill to process a φ11mm hole, which not only prepares for roughing the φ22mm hole, but also reduces the tool vibration caused by the subsequent end mill due to excessive full cutting load, but also performs center positioning for the φ5mm and φ7mm deep holes, further ensuring concentric drilling of the two deep holes, and then use a φ20 alloy milling cutter to process the φ22mm hole, and finally complete the processing of the φ5mm and φ7mm deep holes in sequence.

[0041] S3 completes the φ11mm shallow hole processing, φ22mm countersink processing, M6 bottom hole processing, φ5mm deep hole processing, φ7mm deep hole processing and M6 threaded hole processing on the bearing shell in sequence based on the processing sequence;

[0042] Specifically, to complete the φ11mm shallow hole processing, first use the center drill bit to drill a 3mm deep center hole for φ11mm hole positioning, and then use the φ11mm alloy hard drill bit to drill the φ11mm hole, with a speed of 800r / min, a feed of 60mm / min, and a drilling depth of 34mm. Figure 3 As shown in the figure, the original depth of the φ11mm hole is 31mm, and the actual drilling depth is 3mm more. This has two main functions: one is to perform center positioning for the φ5mm and φ7mm deep holes to further ensure concentric drilling of the two deep holes; the other is to chamfer the φ7mm deep hole to remove burrs;

[0043] The φ22mm countersink processing is completed, and the φ11mm shallow hole drilling has completed the roughing preparation for the φ22mm countersink. The φ20mm alloy hard end mill adopts a speed of 800r / min, a feed of 80mm / min, a cutting amount of 2mm, and a round tool compensation method to complete the milling of the 22mm diameter and 16mm depth countersink. Figure 4As shown in the figure, the tool is not in full engagement during the milling process. Using a φ11mm alloy drill bit for roughing first can effectively avoid the phenomenon that the tool vibration caused by excessive load due to full engagement leads to the hole size and roughness not meeting the requirements.

[0044] Complete the M6 ​​bottom hole and φ5mm deep hole processing. There is a φ11mm alloy hard drill with an extra drilling depth of 3mm in front. There is a pre-drilled center hole for subsequent deep hole processing. The φ5mm deep hole is processed first because the depth of the φ5mm deep hole is greater than that of the φ7mm deep hole. It belongs to the inclusive relationship. The φ5mm drill bit drills at the pre-drilled center hole position, indicating that the φ5mm and φ7mm deep holes use the same positioning center hole, directly ensuring that the φ11mm, φ7mm, and φ5mm holes are concentric, avoiding multiple positioning holes, resulting in the offset of the multi-hole drilling tool and causing eccentricity. The φ5mm drill bit uses a speed of 800r / min, a feed of 30mm / min, and a cutting amount of 3mm to complete the deep hole drilling of the M6 ​​bottom hole with a diameter of 5mm and a depth of 60mm. Figure 5 As shown;

[0045] To complete the φ7mm deep hole processing, the φ7mm drill bit uses a speed of 760r / min, a feed of 60mm / min, and a cutting depth of 3mm to complete the deep hole drilling of 7mm diameter and 45mm depth. Figure 6 As shown, this depth is 2mm deeper than the original depth. Its main function is to chamfer and remove burrs of φ5mm and guide M6 tapping.

[0046] To complete the M6 ​​threaded hole processing, the M6 ​​tap uses a speed of 150r / min. The feed will be calculated based on the pitch and speed. Finally, the M6 ​​threaded hole processing is completed. Figure 7 shown.

[0047] S4 performs gear and precision inspection on the processed bearing shell.

[0048] Specifically, after all holes were machined, they were inspected for size and accuracy, and the results all met the requirements.

[0049] It is mainly implemented for superimposed deep holes of different diameters. This implementation method takes the bearing shell as an example. Figure 1 As shown, the cross-sectional view of the bearing shell with superimposed deep holes of different diameters, a total of 4 superimposed deep holes, the enlarged view of the deep hole structure is shown in Figure 2 As shown, the tolerance requirement for φ22mm countersunk hole is ±0.2mm, hole depth is 16mm, and bottom roughness is 1.6; the tolerance requirement for φ11mm shallow hole is ±0.1mm, hole depth is 31mm, and side roughness is 1.6; the tolerance requirement for φ7mm deep hole is 43mm, and the drilling depth of M6 threaded deep hole is 60mm and the tapping depth is 55mm. The roughness requirement for the others is 3.2.

[0050] The present invention provides a method for machining overlapping deep holes of different diameters, primarily addressing the eccentricity issue of overlapping deep holes of different diameters. By changing the hole machining sequence and rationally selecting the tool, the jitter and offset that often occur when machining deep holes are avoided. The present invention's machining method involves first machining a φ11mm hole with a φ11mm alloy drill. The alloy drill is more rigid than an ordinary twist drill and offers improved drilling stability. This alloy drill not only addresses the 1.6 roughness issue for φ11mm holes but also prepares for roughing φ22mm holes, reducing tool vibration caused by excessive full engagement load on subsequent end mills. It also provides centering for the φ5mm and φ7mm deep holes, further ensuring concentric drilling of the two deep holes. A φ20 alloy milling cutter is then used to machine the φ22mm hole, completing the machining of the φ5mm and φ7mm deep holes in sequence. Compared to the original hole processing sequence, the patented φ11mm alloy drill is a key step. The alloy drill is a carbide drill with good rigidity and high hardness. When drilling φ11mm shallow holes, it can not only accurately and continuously locate the φ11mm center, but also complete the pre-drilling of φ5mm and φ7mm deep holes. The pre-drilled center hole here ensures the concentricity of the φ11mm, φ7mm, and φ5mm holes, which plays a very important positioning role in deep hole drilling and can prevent small drill bits from offsetting due to the lack of positioning holes. This processing method not only solves the problem of eccentricity in deep holes of different diameters, but also ensures the quality of complex bearing housings.

[0051] The above disclosure is only a preferred embodiment of the method for processing deep holes with superimposed holes of different diameters of the present invention. Of course, this cannot be used to limit the scope of rights of the present invention. Ordinary technicians in this field can understand that implementing all or part of the processes of the above embodiment and making equivalent changes in accordance with the claims of the present invention still fall within the scope of the invention.

Claims

1. A method for machining deep holes with different diameters, used for machining a bearing shell, wherein the bearing shell has a Ø11mm shallow hole, a Ø22mm countersunk hole, an M6 bottom hole, a Ø5mm deep hole, a Ø7mm deep hole and an M6 threaded hole, characterized in that: The following steps are involved: Determine the tool; Determine the machining sequence based on the determined tool; Based on the processing sequence, the bearing shell is processed in sequence with a Ø11mm shallow hole, a Ø22mm countersink, an M6 bottom hole, a Ø5mm deep hole, a Ø7mm deep hole, and an M6 threaded hole; Performing gear and precision inspection on the machined bearing shell; The determining of the tool comprises: Use 22mm alloy hard milling cutter to fill the hole with a round cutter for milling, use 11mm alloy hard drill for drilling, and use ordinary twist drill and tap to complete the drilling and tapping of 7mm and M6. The processing sequence is: first use a Ф11mm alloy drill to process a Ф11mm hole, then use a Ф20 alloy milling cutter to process a Ф22mm hole, and finally complete the processing of two deep holes of Ф5mm and Ф7mm in sequence; The Ø11mm shallow hole processing includes: First, use a center drill bit to drill a 3mm deep center hole, then use a 11mm alloy hard drill bit to drill a 11mm hole, with a speed of 800r / min, a feed of 60mm / min, and a drilling depth of 34mm; The 22mm Ø countersink processing includes: A 20mm diameter alloy hard end mill was used at a speed of 800r / min, a feed of 80mm / min, a cutting depth of 2mm, and a rounding tool filling method to complete the milling of a countersink with a diameter of 22mm and a depth of 16mm. The M6 ​​bottom hole and Ф5mm deep hole processing include: First, a Ф5mm deep hole is processed. The Ф5mm drill bit drills at the pre-drilled center hole position. The Ф5mm and Ф7mm deep holes use the same positioning center hole to directly ensure that the Ф11mm, Ф7mm, and Ф5mm holes are concentric. The Ф5mm drill bit uses a speed of 800r / min, a feed of 30mm / min, and a cutting depth of 3mm to complete the deep hole drilling of the M6 ​​bottom hole with a diameter of 5mm and a depth of 60mm.

2. The method for machining deep holes with overlapping holes of different diameters according to claim 1, wherein: The 7mm deep hole processing includes: The Ф7mm drill bit uses a rotation speed of 760r / min, a feed of 60mm / min, and a cutting depth of 3mm to complete deep hole drilling with a diameter of 7mm and a depth of 45mm.

3. The method for machining deep holes with overlapping holes of different diameters according to claim 2, wherein: The M6 ​​threaded hole processing includes: Calculate the feed rate based on the pitch and speed; The M6 ​​tap uses a rotation speed of 150 r / min and, based on the feed rate, completes the M6 ​​threaded hole machining.

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