A method for processing an inner stepped end face hole in angular position relation with an outer circular groove

Abstract

The application discloses a processing method of an inner stepped end face hole with an angular position relation with an outer circular groove, and belongs to the technical field of machining. The processing method realizes the following steps: step one: processing a circular hole D2 and a straight groove, ensuring the position degree of the straight groove to a reference A and controlling the tolerance of the circular hole D2; step two: positioning the inner stepped end face hole by using a drill jig with the circular hole D2 as a reference; and step three: locking the drill jig and the part, and processing the inner stepped end face hole M of the inner hole D1 through the positioning hole on the drill jig. The processing method can reduce the error of indirect leveling, eliminate the accumulated error of the existing processing method, and improve the machining precision of the part.

Description

Technical Field

[0001] This invention relates to the field of machining technology, and specifically to a machining method for an inner stepped end face that has an angular positional relationship with an outer circular groove. Background Technology

[0002] like Figure 1 As shown, the inner diameter of the part to be machined is D1 (reference A), and the depth is L1; the diameter of the circumferential hole is D2, and the axial distance from the left end face is L2, penetrating from the outer circle to the inner hole; the outer diameter is D3. The width of the straight groove on the outer circle is L3 (reference B), and the straight groove and the circumferential hole D2 are axially connected; the drawing requires a positional tolerance of 0.2mm relative to reference A. There are 8 threaded holes M, requiring a positional tolerance of Φ0.25mm relative to references A and B.

[0003] The common machining method involves first reserving a section of the blank's outer diameter, and then machining a directional keyway on the blank's outer diameter for angular positioning. Then, the blank is installed as follows... Figure 2 The drill jig is shown and positioned using a directional key. The angular machining of the circumferential hole D2 and the straight groove are determined by leveling the reference plane on the drill jig. Then, eight threaded holes M are machined using the positioning holes on the drill jig. After machining, the excess blank outer diameter is machined off and aligned with the machined outer diameter.

[0004] Because the depth L1 of the inner hole D1 of the part is relatively large, the drill jig used in this machining method is long and heavy, making installation and disassembly inconvenient. Positioning is achieved using keyways and flat keys, and the angular positions of the outer diameter groove and the circumferential hole D2 are determined by aligning the reference plane. The positional accuracy of the two keyways on the workpiece and the drill jig, the assembly accuracy between the key and the keyway, and the leveling accuracy of the drill jig's reference plane all affect the final machining accuracy, and the cumulative effect of various errors is relatively large. Summary of the Invention

[0005] In view of this, the present invention provides a method for machining an inner stepped end face with an angular positional relationship to the outer circular groove, which can reduce the error of indirect leveling and eliminate the cumulative error of existing machining methods, thereby improving the machining accuracy of the parts.

[0006] A method for machining an end face of an inner stepped groove that has an angular positional relationship with the outer circular groove, the steps of which are as follows:

[0007] Step 1: Machining the circumferential hole D2 and the straight groove to ensure their positional accuracy relative to datum A, and controlling the tolerance of the circumferential hole D2;

[0008] Step 2: Using the circumferential hole D2 as a reference, use the drill jig to locate the hole at the end of the inner step;

[0009] Step 3: Lock the drill jig and the part, and machine the inner step end hole M of the inner hole D1 through the positioning hole on the drill jig.

[0010] Furthermore, in step one, the positional accuracy of the circumferential hole D2 relative to the reference A is 0.2 mm.

[0011] Furthermore, in step three, the angular position of the inner stepped end face M of the inner hole D1 relative to reference A and reference B is Φ0.25mm.

[0012] Furthermore, the drill jig includes a body, a locating pin, and a locking bolt;

[0013] The body is a cylindrical structure with a central through hole. The axial length of the body is greater than the distance between the inner stepped end face of the circumferential hole D2 and the inner hole D1. The outer circle of the body is clearance-fitted with the inner hole D1. A keyway is machined on the outer circle of the body, and the width of the keyway is the same as the diameter of the circumferential hole D2. Bolt holes are machined on the body in a circumferential direction. The bolt holes penetrate the inner and outer surfaces of the body radially. Locking bolts are fitted into the bolt holes, and the bolt head of the locking bolt faces the central through hole of the body.

[0014] The diameter of the locating pin is smaller than the diameter of the circumferential hole D2.

[0015] Furthermore, the bolt head of the locking bolt adopts an internal hexagonal structure, and the locking bolt can be tightened and loosened by an L-shaped internal hexagonal wrench.

[0016] Beneficial effects:

[0017] 1. The processing method of the present invention uses the circumferential hole D2 as a reference to locate the inner stepped end hole using a drill jig, which avoids the cumulative error generated when machining the directional keyway on the outer circle of the blank for angular positioning and aligning in conventional processing methods, and can greatly improve the processing accuracy of the parts.

[0018] 2. The axial length of the main body in the drilling jig of the present invention is greater than the distance between the inner step end face of the circumferential hole D2 and the inner hole D1. Compared with the conventional drilling jig, whose length is equal to the depth L1 of the inner hole D1 of the part, the length can be reduced by about 2 / 3, which reduces raw materials and saves costs.

[0019] 3. The present invention uses the circumferential hole D2 and the positioning keyway on the drill jig body to directly position the jig via the cylindrical positioning pin, which reduces the error of indirect leveling and further improves the machining accuracy. Attached Figure Description

[0020] Figure 1 This is a diagram showing the structure and dimensions of the part to be processed.

[0021] Figure 2 This is a schematic diagram of a drill jig structure in the prior art;

[0022] Figure 3 This is a schematic diagram of the drill jig structure used in this invention.

[0023] Among them, 1-body, 2-positioning pin, 3-locking bolt. Detailed Implementation

[0024] The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0025] This invention provides a method for machining an inner stepped end face with an angular positional relationship to an outer circular groove. This method requires the use of the method described in the attached diagram. Figure 3 The drill jig shown in this invention includes a body 1, a positioning pin 2, and a locking bolt 3.

[0026] The body 1 is a cylindrical structure with a central through hole. The axial length of the body 1 is greater than the distance between the inner stepped end face of the circumferential hole D2 and the inner hole D1. The outer circle of the body 1 is clearance-fitted with the inner hole D1 of the part. A keyway is machined on the outer circle of the body 1, and the width of the keyway is the same as the diameter of the circumferential hole D2 on the part. Like a conventional drill jig, the body 1 has a positioning hole for positioning the drill bit. Bolt holes are also machined on the body 1 in a circumferential direction, penetrating the inner and outer surfaces of the body 1 radially. Locking bolts 3 are fitted into the bolt holes, with the bolt head of the locking bolt 3 facing the central through hole of the body 1. The bolt head of the locking bolt 3 has an internal hexagonal structure, and the locking bolt is tightened and loosened using an L-shaped internal hexagonal wrench. The diameter of the positioning pin 2 is smaller than the diameter of the circumferential hole D2.

[0027] The processing method involves the following steps:

[0028] Step 1: First, machine the circumferential hole D2 and the straight groove to ensure their position relative to datum A, and control the tolerance of the circumferential hole D2; according to the drawing requirements, the position of the straight groove and the circumferential hole D2 relative to datum A (inner hole D1) needs to be 0.2mm.

[0029] Step 2: Using the circumferential hole D2 as a reference, use a drill jig to position the inner step end hole. The positioning process is to first insert the body 1 into the inner hole D1 of the part, and use a positioning pin 2 to pass through the circumferential hole D2. Adjust the angular position of the body 1 so that the positioning pin passes into the keyway of the body 1 to determine the angular position of the body.

[0030] Step 3: Use an Allen wrench to turn the locking bolt 3, causing it to extend radially and press against the inner wall of the inner hole D1 of the part, thereby locking the body 1 and the part together. Then, machine the inner stepped end face hole M of the inner hole D1 through the positioning hole on the body 1. The angular positional tolerance of the eight holes M on the end face of the inner hole D1 to reference A (inner hole D1) and reference B (outer circle upper groove) is Φ0.25mm.

[0031] In summary, the above are merely preferred embodiments of the present invention and are not intended to limit the scope of protection of the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A method for machining an inner stepped end face with an angular positional relationship to an outer circular groove, characterized in that, The processing method involves the following steps: Step 1: Machining the circumferential hole D2 and the straight groove to ensure their positional accuracy relative to datum A, and controlling the tolerance of the circumferential hole D2; Step Two: First, install the main body into the inner hole D1 of the part. The main body is a cylindrical structure with a central through hole. The axial length of the main body is greater than the distance between the circumferential hole D2 and the inner stepped end face of the inner hole D1. The outer circle of the main body is clearance-fitted with the inner hole D1. A keyway is machined on the outer circle of the main body, and the width of the keyway is the same as the diameter of the circumferential hole D2. Bolt holes are machined on the main body in a circumferential direction, and the bolt holes penetrate the inner and outer surfaces of the main body radially. Locking bolts are installed in the bolt holes, with the bolt head facing the central through hole of the main body. A locating pin is inserted through the circumferential hole D2. The diameter of the locating pin is smaller than the diameter of the circumferential hole D2. Adjust the angular position of the main body so that the locating pin enters the keyway of the main body to determine the angular position of the main body. Use an Allen wrench to rotate the locking bolt so that the locking bolt extends radially and presses against the inner wall of the inner hole D1 of the part, thereby locking the main body and the part. Use a drill jig to locate the inner stepped end face using the circumferential hole D2 as a reference. Step 3: Lock the drill jig and the part, and machine the inner step end hole M of the inner hole D1 through the positioning hole on the drill jig.

2. The method for machining an inner stepped end face with an angular positional relationship to an outer circular groove as described in claim 1, characterized in that, In step one, the positional accuracy of the circumferential hole D2 relative to the reference A is 0.2 mm.

3. The method for machining an inner stepped end face with an angular positional relationship to an outer circular groove as described in claim 2, characterized in that, In step three, the angular position of the inner stepped end face M of the inner hole D1 relative to reference A and reference B is Φ0.25mm.

4. The method for machining an inner stepped end face with an angular positional relationship to an outer circular groove as described in claim 3, characterized in that, The locking bolt has an internal hexagonal head, and the locking bolt can be tightened and loosened using an L-shaped internal hexagonal wrench.

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