A compound drill for machining flange face hole and chamfering front and back face of differential housing

Abstract

The utility model discloses a kind of differential housing flange face hole and chamfering of front and back face composite drill, belong to the technical field of automobile parts machining.The composite drill includes drill bit and tool bar, the drill bit is divided into three sections along its axial direction: root diameter is matched with product aperture, for drilling;Middle area is to avoid empty reduced section, for realizing eccentric reverse pull provides movement space;End is amplification section, for processing front chamfer.The utility model integrates three functions of drilling, front chamfering, back chamfering in a tool, can continuously complete all processing by once clamping on vertical machining center, without replacing tool or increasing separate process, greatly improve processing efficiency, and effectively guarantee the machining quality and consistency of front and back chamfering of orifice, fundamentally eliminate back burr, improve the cleanliness and assembly reliability of differential assembly.

Description

Technical Field

[0001] This utility model relates to the field of drilling equipment, and in particular to a composite drill for drilling holes and forward and reverse chamfering of differential housing flange faces. Background Technology

[0002] The differential housing is a key component in a car's drive axle. The connecting holes on its flange are used for assembly with the driven gear. The machining quality and cleanliness of these holes directly affect the assembly accuracy, operational smoothness, and service life of the differential assembly. Currently, the machining of the flange holes in the differential housing typically requires several independent steps, including drilling, chamfering the front side, and deburring or chamfering the back side (burred surface).

[0003] There are two main processing methods currently available: The first involves using automated equipment such as vertical machining centers to first drill and chamfer the front side, then replacing the workpiece with a dedicated eccentric tool or a disposable reverse-pull chamfering tool to perform reverse-pull chamfering on the back side. The drawback of this method is that each hole requires a tool change or additional reverse-pull operation, severely impacting the processing cycle and leading to low production efficiency, becoming a bottleneck restricting product output. The second method, aimed at reducing processing costs, adds a separate step after drilling and chamfering the front side: using a small bench drill in conjunction with manual deburring on the back side. This manual operation is not only inefficient but also unstable. During processing, if the workpiece is not securely clamped or the drill bit wears down, incomplete deburring is highly likely.

[0004] The problems with the existing technical solutions are obvious: low processing efficiency, high cost, and difficulty in ensuring stable processing quality. Unremoved burrs will seriously affect the cleanliness of the differential. During subsequent operation, detached metal shavings may adhere to the surface of the differential gears, causing abnormal gear wear, abnormal noise during operation, and in turn causing NVH (noise, vibration, and harshness) problems in the entire vehicle, affecting the quality of the car and the driving experience.

[0005] Therefore, there is an urgent need in the field for a high-efficiency composite tool that can integrate drilling and chamfering functions, complete the machining in one go, and ensure machining quality, so as to overcome the above-mentioned defects of the prior art. Utility Model Content

[0006] The purpose of this invention is to overcome the deficiencies of the existing technology and provide a composite drill for drilling holes and chamfering in both directions on a differential housing flange.

[0007] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A composite drill for machining flange holes and chamfering on both sides of a differential housing includes a drill bit having a root, a middle region, and an end. The diameter of the root is adapted to the aperture of the flange hole in the differential housing. The diameter of the middle region is smaller than the diameter of the root to form a clearance zone for achieving chamfering on the reverse side through eccentric reverse pull. The diameter of the end is larger than the diameter of the root for achieving chamfering on the front side.

[0008] Furthermore, the drill bit is a cemented carbide drill bit.

[0009] Furthermore, the composite drill also includes a tool holder connected to the drill bit and used for mounting on the spindle of a vertical machining center.

[0010] Furthermore, the cutter bar is integrated with the drill bit in the middle region to drive the drill bit to achieve reverse chamfering during eccentric motion.

[0011] Furthermore, the clearance zone in the intermediate region is configured to chamfer the reverse side of the differential housing bore when the composite drill moves upward and deviates from the center.

[0012] Furthermore, the end is formed with a front chamfering blade for chamfering the front side of the hole after drilling.

[0013] Furthermore, the root is configured to perform a drilling operation, and its diameter is consistent with the diameter of the hole in the differential housing flange.

[0014] Furthermore, the composite drill integrates drilling, front chamfering, and back chamfering functions, making it suitable for machining without tool changes in vertical machining centers.

[0015] Furthermore, the diameter of the middle region is smaller than the diameter of the root, and the diameter of the end is larger than the diameter of the root, forming a stepped structure.

[0016] The beneficial effects of this utility model are as follows: 1. This utility model integrates the three steps of drilling, front chamfering, and back chamfering into a single tool and completes them continuously in one setup. This completely avoids the processing interruptions caused by changing tools or adding separate processes in the prior art, significantly shortens the processing cycle of a single hole, and thus greatly improves the overall production efficiency; 2. The mechanical chamfering of the reverse side is achieved through the structural design of the cutting tool, completely replacing the unstable manual operation. This results in uniform and consistent chamfer dimensions on both sides of the hole, effectively avoiding incomplete deburring caused by human factors or tool wear, and fundamentally improving product quality. 3. By thoroughly removing burrs and metal filings, the root cause of abnormal noise caused by metal debris interfering with gear meshing is eliminated, which helps to improve the NVH (noise, vibration, and harshness) performance of the differential and even the whole vehicle, thus improving the quality and driving comfort of the car. 4. This utility model combines multiple processes into one, simplifies the production process, reduces reliance on dedicated reverse chamfering equipment or additional manual tables, not only saves equipment investment costs, but also reduces the fixture, labor and management costs caused by multiple processes. Attached Figure Description

[0017] To more clearly illustrate the specific embodiments of this utility model or the technical solutions in the prior art, the drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are some embodiments of this utility model. For those skilled in the art, other drawings can be obtained from these drawings without creative effort.

[0018] Figure 1 This is a schematic diagram of the structure of this utility model; Figure 2 This is a schematic diagram of the machining of the flange hole in the differential housing of this utility model; Figure 3 This is a schematic diagram of the chamfering process for drilling flange holes in the differential housing according to this utility model; Figure 4 This is a schematic diagram showing the machining of the reverse side of the differential housing hole of this utility model. Detailed Implementation

[0019] The technical solution of this utility model will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0020] refer to Figure 1 As shown in the figure, this embodiment provides a composite drill for machining flange holes and chamfering on both sides of a differential housing, mainly composed of a carbide drill bit 1 and a tool holder 2. The composite drill has a specially designed structure, which can be divided into three functionally distinct sections along its axial direction: Drill root (drilling section) 11: This section is located at the very front of the tool. Its diameter is precisely designed to match the target hole diameter of the flange face to be machined on the differential housing 3. It is specifically responsible for drilling operations to ensure accurate hole diameter dimensions. Drill bit middle section (avoidance section) 12: This section follows the root and its diameter is significantly reduced, forming an avoidance zone. The key purpose of this design is to provide space for the tool to yaw when the tool has finished drilling and needs to be chamfered on the reverse side, allowing it to cut the reverse edge of the hole through eccentric movement without interfering with the hole wall.

[0021] Drill bit tip (face chamfer section) 13: This section is located after the middle area, and its diameter is enlarged to form a chamfering edge. This section is used to chamfer the front entrance of the hole immediately after drilling is completed.

[0022] The composite drill is securely mounted on the spindle of a vertical machining center via a tool holder, requiring the machining equipment to have at least three-axis linkage capabilities to achieve the required vertical feed and eccentric motion.

[0023] The processing of the composite drill includes the following steps in sequence: Step 1: Drilling (see...) Figure 2 The spindle of the vertical machining center starts, driving the compound drill to rotate at high speed and feed vertically downward along the Z-axis. At this time, the root of the drill bit (drilling section) 11 at the front end of the compound drill first contacts the flange face of the differential housing 3 and begins to cut the material until it drills through the entire thickness of the flange face, forming a smooth hole.

[0024] Step 2: Chamfering the front edge (see...) Figure 3 After hole 31 is drilled through, the spindle of the vertical machining center does not immediately retract, but continues to feed downwards for a short distance. At this point, the hole diameter has been formed by the preceding drilling section 11, so the larger diameter drill bit end (face chamfer section) 13 enters the hole. Because its diameter is larger than the hole diameter, the cutting edge on this section will naturally cut the front edge of the hole opening, forming a uniform and smooth face chamfer.

[0025] Step 3: Chamfering the reverse side (see...) Figure 4 After the chamfering on the front side is completed, the vertical machining center spindle stops feeding downwards and begins to move upwards. Crucially, this upward movement is not a simple vertical retraction, but rather, driven by the spindle control system, the spindle causes the composite drill to produce a slight eccentric displacement in the XY plane, preferably 0.5mm. In this state, as the composite drill moves upwards, part of the cutting edge of its central area (avoidance section) 12 contacts the opposite edge (exit) of the hole 31 due to the eccentricity. Because the diameter of the avoidance section 12 is small, it provides the necessary space for this eccentric cutting. Through precise control, the tool can complete the removal of burrs and chamfering on the opposite side of the hole during the retraction process.

[0026] Through the above three consecutive steps, this invention seamlessly completes all three processes of drilling, chamfering the front and back sides of the differential housing flange face using a single tool in a single clamping operation. The entire machining process is smooth and efficient, requiring no tool changes, secondary clamping, or additional manual operations. This not only greatly improves production efficiency but also ensures stable and reliable machining quality due to the precision guaranteed by CNC equipment throughout the process. It completely eliminates the potential for residual burrs on the back side, thereby effectively improving the cleanliness and assembly quality of the differential assembly.

[0027] The above description is merely a preferred embodiment of this utility model, but the protection scope of this utility model is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the technical scope disclosed in this utility model, based on the technical solution and inventive concept of this utility model, should be included within the protection scope of this utility model.

Claims

1. A composite drill for machining flange holes and chamfering on both sides of a differential housing, characterized in that, The device includes a drill bit having a root, a middle region, and an end. The diameter of the root is adapted to the bore diameter of a differential housing flange face. The diameter of the middle region is smaller than the diameter of the root to form a clearance zone for achieving reverse chamfering through eccentric back pull. The diameter of the end is larger than the diameter of the root for achieving front chamfering.

2. The composite drill according to claim 1, characterized in that, The drill bit is a cemented carbide drill bit.

3. The composite drill according to claim 1, characterized in that, The composite drill also includes a tool holder connected to the drill bit and used for mounting on the spindle of a vertical machining center.

4. The composite drill according to claim 3, characterized in that, The cutter bar is integrated with the drill bit in the middle region and is used to drive the drill bit to achieve reverse chamfering during eccentric motion.

5. The composite drill according to claim 1, characterized in that, The clearance zone in the middle area is configured to chamfer the reverse side of the differential housing bore when the composite drill moves upward and deviates from the center.

6. The composite drill according to claim 1, characterized in that, The end is formed into a front chamfering blade, which is used to chamfer the front side of the hole after drilling.

7. The composite drill according to claim 1, characterized in that, The root is configured to perform a drilling operation, and its diameter is consistent with the diameter of the hole in the differential housing flange.

8. The composite drill according to claim 1, characterized in that, The composite drill integrates drilling, front chamfering, and back chamfering functions, and is suitable for machining without tool changes in vertical machining centers.

9. The composite drill according to claim 1, characterized in that, The diameter of the middle region is smaller than the diameter of the root, and the diameter of the end is larger than the diameter of the root, forming a stepped structure.

Images