Grinding and honing machining method for blind hole or stepped hole with ultra-large length-diameter ratio

Abstract

The invention relates to the technical field of honing, in particular to a honing machining method for a blind hole or a stepped hole with an ultra-large length-diameter ratio, which comprises the following steps of: 1, performing internal grinding on the hole bottom of a hole to be machined through a grinding head of a grinding machine, grinding a tool withdrawal groove on the hole wall of the hole bottom, the side groove surfaces are parallel to the axis of the to-be-machined hole, and the inner diameter of an inner circle formed by the side groove surfaces of the tool withdrawal groove is the same as the target inner diameter of the to-be-machined hole; step 2, performing internal grinding on the to-be-processed hole above the tool withdrawal groove through a grinding head, and processing the straightness of the to-be-processed hole above the tool withdrawal groove; and thirdly, the hole wall of the hole to be machined is honed through a honing tool of the honing equipment, reticulate patterns are machined on the hole wall of the hole to be machined, the inner diameter of the part, above the tool withdrawal groove, of the hole to be machined is honed to be the same as the inner diameter of the tool withdrawal groove, and the honed hole wall is connected with the side groove face of the tool withdrawal groove. The roundness is high, and the perpendicularity is good.

Description

Technical Field

[0001] The invention relates to the technical field of honing, in particular to a honing method for a blind hole or a step hole with a super-large aspect ratio. Background Art

[0002] Blind holes or step holes with a large aspect ratio have processing requirements of high straightness, high roundness and honing patterns, and require high verticality of the hole bottom, such as the rod barrel of a large oil cylinder. However, the existing technology lacks a suitable processing method that can meet the above processing requirements.

[0003] Blind holes or step holes with super-large aspect ratio cannot be machined with tools and can only be machined with deep hole drills. The holes machined with deep hole drills have problems such as poor straightness, uneven hole walls, and serpentine shapes. The honing process of the honing tool can ensure the roundness of the hole, but it is difficult to ensure the straightness of the hole. Therefore, honing cannot be performed directly after deep hole drilling.

[0004] Moreover, the honing head of the honing tool cannot directly hone to the bottom of the hole, resulting in the bottom of the hole not being vertical. Summary of the invention

[0005] The technical problem to be solved by the present invention is: blind holes or step holes with ultra-large aspect ratios have the processing requirements of high straightness, high roundness and honing patterns, and require high verticality of the hole bottom, such as the rod barrel of a large oil cylinder, but the prior art lacks a suitable processing method that can meet the above processing requirements.

[0006] The technical solution adopted by the present invention is: a grinding and honing method for a blind hole or a step hole with a super-large aspect ratio, comprising the following steps:

[0007] Step 1: grinding the bottom of the hole to be processed by the grinding head of the grinding machine, grinding a back cut groove on the hole wall at the bottom of the hole, the side groove surface and the lower groove surface of the back cut groove are straight lines, and the side groove surface is parallel to the axis of the hole to be processed, and the inner diameter of the inner circle formed by the side groove surface of the back cut groove is the same as the target inner diameter of the hole to be processed;

[0008] Step 2: internally grinding the hole to be processed on the undercut groove by a grinding head to obtain the straightness of the hole to be processed on the undercut groove;

[0009] Step three, honing the hole wall of the hole to be processed by the honing tool of the honing equipment, processing the mesh pattern on the hole wall of the hole to be processed, and honing the inner diameter of the hole to be processed above the back cutter groove to be the same as the inner diameter of the back cutter groove, so that the honed hole wall is connected with the side groove surface of the back cutter groove.

[0010] Furthermore, the upper groove surface of the undercut groove is inclined upward, the lower groove surface of the undercut groove is perpendicular to the side groove surface of the undercut groove, and the side profile of the grinding head is the same as the cross-sectional shape of the undercut groove.

[0011] Furthermore, the angle A between the upper groove surface of the tool retreat groove and the axis of the hole to be processed is 20 to 30 degrees.

[0012] Compared with the prior art, the present invention has the following advantages:

[0013] Firstly, the internal grinding with a grinding head can ensure the straightness of the hole to be processed, and then honing is performed to hone out the roundness and reticulation, so that the processed blind hole or step hole has high straightness, high roundness and reticulation on the surface;

[0014] The design of the back-cut groove can overcome the problem that the honing head of the honing tool cannot directly hone to the bottom of the hole, resulting in the hole bottom being not vertical, so that the bottom verticality of the processed blind hole or step hole is high;

[0015] The upward tilted upper groove surface of the undercut protects the honing tool and prevents the upper opening of the undercut from forming a sharp portion that scratches the end of the honing stick of the honing tool.

[0016] In summary, the honing method of a blind hole or a step hole with a super-large aspect ratio of the present invention has the advantages of simple processing, high straightness and roundness of the processed blind hole or step hole, and the ability to form a reticulation on the surface, and can ensure the verticality of the bottom of the hole. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a cross-sectional view of a blind hole workpiece with a very large aspect ratio;

[0018] Figure 2 yes Figure 1 The enlarged view of point A in the middle;

[0019] Figure 3 yes Figure 1 Cross-sectional view of the workpiece and grinding head after matching;

[0020] Figure 4 yes Figure 3 Enlarged view of point C in the middle;

[0021] Figure 5 yes Figure 1 The cross-sectional view of the workpiece after being cut and polished by the grinding head;

[0022] Figure 6 yes Figure 5 The enlarged view of point B in the middle;

[0023] Figure 7 is a schematic diagram of the structure of the grinding head;

[0024] Figure 8 yes Figure 7 The enlarged view of point D in the middle;

[0025] Fig. 9 yes Figure 8 Attached is a schematic diagram with specific dimensions marked;

[0026] Fig.10 yes Figure 1 A partial cross-sectional view of the workpiece after honing;

[0027] In the figure: 1. workpiece, 2. wavy pattern, 3. tool recess, 4. grinding head, 5. mesh pattern. DETAILED DESCRIPTION

[0028] The present invention will now be described in further detail in conjunction with the accompanying drawings and preferred embodiments. These drawings are simplified schematic diagrams, which only illustrate the basic structure of the present invention in a schematic manner, and therefore only show the components related to the present invention.

[0029] like Figures 1 to 10 A grinding and honing method for a blind hole or a step hole with a large aspect ratio is shown, wherein the hole to be processed is a blind hole. As in the prior art, the blind hole is processed by deep hole drilling, and the blind hole processed by the deep hole drilling is the hole to be processed. Figure 1 The depth of the blind hole in the workpiece is greater than or equal to fifteen times the inner diameter of the blind hole, that is, a blind hole with an extremely large aspect ratio. The blind hole processed by deep hole drilling in workpiece 1 has poor roundness, uneven hole walls, and poor straightness. Figure 2 A snake-like wave pattern 2 will appear.

[0030] The grinding and honing method of the blind hole or step hole with a super-large aspect ratio comprises the following steps:

[0031] Step 1: The bottom of the hole to be processed is internally ground by the grinding head 4 of the grinding machine, and a backhoe groove 3 is ground on the hole wall at the bottom of the hole. The side groove surface and the lower groove surface of the backhoe groove 3 are straight lines, and the side groove surface is parallel to the axis of the hole to be processed. The inner diameter of the inner circle formed by the side groove surface of the backhoe groove 3 is the same as the target inner diameter of the hole to be processed;

[0032] Step 2: internally grinding the hole to be processed on the undercut groove 3 by the grinding head 4 to obtain the straightness of the hole to be processed on the undercut groove 3;

[0033] Step 3: honing the hole wall of the hole to be processed by the honing tool of the honing equipment, processing the mesh 5 on the hole wall of the hole to be processed, and honing the inner diameter of the hole to be processed above the undercut groove 3 to be the same as the inner diameter of the undercut groove 3, so that the honed hole wall is connected with the side groove surface of the undercut groove 3, and the mesh 5 processed on the hole wall is preferably a cross mesh;

[0034] The upper groove surface of the undercut groove 3 is inclined upward, the lower groove surface of the undercut groove 3 is perpendicular to the side groove surface of the undercut groove 3 , and the side profile of the grinding head 4 is the same as the cross-sectional shape of the undercut groove 3 .

[0035] The included angle A between the upper groove surface of the undercut groove 3 and the axis of the hole to be processed is 20 to 30 degrees.

[0036] In the present invention, the workpiece 1 is mounted on a turntable, and the turntable drives the workpiece 1 to rotate. Through the rotation of the workpiece, the grinding head 4 performs internal grinding by radial feeding, and the grinding head 4 extends into the hole to be processed through its grinding rod, that is, Figure 1 In the blind hole, Fig. 9 The height H1 of the straight section of the side surface of the middle grinding head 4 is 2-5 mm, the height H2 of the inclined section is 2-3 mm, and the angle B between the inclined section and the axis of the grinding rod is 20-30 degrees.

[0037] The grinding head 4 is a grinding wheel grinding head. The grinding head for grinding the undercut groove 3 and the grinding head for grinding the hole to be processed on the undercut groove 3 can be the same grinding head or different grinding heads can be used.

[0038] The hole to be processed may be a step hole in addition to the blind hole in this embodiment, and the verticality of the bottom of the large hole section of the step hole can also be ensured.

[0039] The above description only describes the specific implementation mode of the present invention. Various examples do not limit the essential content of the present invention. After reading the description, ordinary technicians in the relevant technical field can modify or deform the specific implementation modes described above without departing from the essence and scope of the invention.

Claims

1. A grinding and honing method for a blind hole or a step hole with a large aspect ratio, characterized in that: The steps include: Step 1: grinding the bottom of the hole to be processed by the grinding head of the grinding machine, grinding a back cut groove on the hole wall at the bottom of the hole, the side groove surface and the lower groove surface of the back cut groove are straight lines, and the side groove surface is parallel to the axis of the hole to be processed, and the inner diameter of the inner circle formed by the side groove surface of the back cut groove is the same as the target inner diameter of the hole to be processed; Step 2: internally grinding the hole to be processed on the undercut groove by a grinding head to obtain the straightness of the hole to be processed on the undercut groove; Step three, honing the hole wall of the hole to be processed by the honing tool of the honing equipment, processing the mesh pattern on the hole wall of the hole to be processed, and honing the inner diameter of the hole to be processed above the back cutter groove to be the same as the inner diameter of the back cutter groove, so that the honed hole wall is connected with the side groove surface of the back cutter groove.

2. The grinding and honing method of a blind hole or a step hole with a large aspect ratio according to claim 1, characterized in that: The upper groove surface of the undercut groove is inclined upward, the lower groove surface of the undercut groove is perpendicular to the side groove surface of the undercut groove, and the side profile of the grinding head is the same as the cross-sectional shape of the undercut groove.

3. The grinding and honing method of a blind hole or a step hole with a large aspect ratio according to claim 2, characterized in that: The angle A between the upper groove surface of the back cut groove and the axis of the hole to be processed is 20 to 30 degrees.

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