CN115625489A - Production method of high-strength bolt part - Google Patents

Abstract

The invention provides a production method of a high-strength bolt part, which comprises the following steps: firstly, processing a blank into a preset workpiece shape; then cutting the rough machined blank into a preset length; then processing the cut blank to obtain a semi-finished product with the size meeting the requirement; machining threads on the semi-finished product; finally, the position of the thread is checked through the checking fixture; the checking fixture is tubular, an internal thread is formed in the inner wall of the checking fixture, the supporting tube extends out of one end of the checking fixture along the axial direction, the internal thread of the checking fixture can be in threaded connection with an external thread machined on a part, and the end face of the supporting tube or the end face of the checking fixture is perpendicular to the axial direction of the part. The invention adopts the mode of arranging the supporting tube on the end surface of the checking fixture, so that the checking fixture can detect various bolts, the application range of the checking fixture is improved, the operation difficulty of operators is reduced, and the detection precision is improved.

Description

A kind of production method of high-strength bolt type parts

technical field

The invention belongs to the field of machining, and in particular relates to a production method of high-strength bolt parts.

Background technique

In the bolt processing process, the workpiece needs to be processed in multiple processes, and then the workpiece is inspected. Due to the limitations of existing equipment and technology, 17 processing steps such as turning the outer circle, cutting, and grinding the outer circle are required for the bar. It not only reduces the processing efficiency, but also needs to clamp the workpiece repeatedly during the processing process, which is not conducive to the positioning of the workpiece, causes the workpiece to be eccentric, and is not conducive to the production of threaded parts with high precision requirements. As far as it is concerned, because there is a large space between the thread and the nut on it, the length of the required inspection tool is increased, resulting in an increase in the processing depth of the standard thread in the inspection tool, which affects the accuracy of the inspection tool.

Invention content

In view of this, the present invention aims to propose a production method for high-strength bolt-like parts, so as to improve production efficiency and reduce the number of clamping times of parts during processing.

In order to achieve the above object, the technical solution created by the present invention is achieved in this way:

A method for producing high-strength bolt-like parts, comprising the following steps:

S1: Rough machining, fix the blank on the machine tool, and process the blank into a preset workpiece shape;

S2: Determine the total length, and cut the rough-machined blank into a predetermined length;

S3: Finishing, processing the cut blank to obtain a semi-finished product, so that the size of the semi-finished product meets the product size requirements;

S4: rolling thread, processing the external thread at the predetermined position of the semi-finished product;

S5: Inspection: inspect the thread position through the inspection tool;

The inspection tool is in the shape of a tube with an internal thread on its inner wall. One end surface of the inspection tool extends out of the support tube in the axial direction, and the inner wall diameter of the support tube is larger than the inner diameter of the test tool. The end faces are parallel, the internal thread of the inspection tool can be screwed with the external thread processed on the part, and the end surface of the support pipe or the end surface of the inspection tool is perpendicular to the axial direction of the part.

Further, after finishing, it is necessary to perform rolling processing on the preset position of the workpiece using the rolling tool of the SR head assembly.

Further, after the rough turning process, blunt and sharp edges are trimmed to the chamfering of the workpiece.

Further, after threading, it is necessary to heat treat the workpiece to improve the rigidity of the workpiece, and to roll the thread after heat treatment.

Further, during the finishing process, the spindle speed of the machine tool is 2200r/min, the feed rate of the cutting tool is 0.08mm/r, and the cutting depth is 0.5mm.

Further, during the working process of the rolling tool, the spindle speed of the lathe is 1500r/min, the feed rate is 0.2mm/r, and the cutting depth is 0.005mm.

Further, the outer diameter of the inspection tool is larger than the outer diameter of the support pipe.

Further, the outer wall of the inspection tool is provided with anti-slip lines, and the position where the outer wall of the inspection tool is provided with anti-slip lines corresponds to the position where the inner wall of the inspection tool is provided with internal threads.

Compared with the prior art, the method for producing high-strength bolt parts described in the invention has the following advantages:

The invention adopts the method of setting the support pipe on the end surface of the inspection tool, so that when the inspection tool is used for bolts with external threads only at the end, the end surface of the support pipe can be pushed against the top after the inspection tool is matched with the thread of the bolt. Then use the feeler gauge to detect the gap between the end surface of the support pipe and the nut, so as to detect the verticality of the thread, shorten the thread processing depth when manufacturing the inspection tool, and reduce the processing difficulty of the inspection tool. Thereby improving the detection accuracy;

After the rough machining process, the workpiece is directly chamfered, thereby reducing the number of clamping times during the workpiece processing;

The workpiece is processed by rolling tools, so that compressive stress is formed on the surface of the workpiece, and the roughness of the surface of the part is improved.

Description of drawings

The accompanying drawings constituting a part of the present invention are used to provide a further understanding of the present invention, and the schematic embodiments and descriptions of the present invention are used to explain the present invention, and do not constitute improper limitations to the present invention. In the attached picture:

Figure 1 is a schematic diagram of the finished parts;

Figure 2 is a schematic diagram of the parts processing flow;

Figure 3 is a schematic diagram of the structure of the inspection tool.

Explanation of reference signs:

1-bolt; 11-nut; 12-rod; 13-sag; 2-checking tool; 21-support pipe; 22-internal thread.

Detailed ways

It should be noted that, in the case of no conflict, the embodiments of the present invention and the features in the embodiments can be combined with each other.

In describing the present invention, it should be understood that the terms "center", "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", The orientations or positional relationships indicated by "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. are based on the orientation or positional relationships shown in the drawings, and are only for the convenience of describing the present invention Creation and simplification of description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be construed as limiting the invention. In addition, the terms "first", "second", etc. are used for descriptive purposes only, and should not be understood as indicating or implying relative importance or implicitly specifying the quantity of the indicated technical features. Thus, a feature defined as "first", "second", etc. may expressly or implicitly include one or more of that feature. In the description of the present invention, unless otherwise specified, "plurality" means two or more.

In the description of the present invention, it should be noted that unless otherwise specified and limited, the terms "installation", "connection" and "connection" should be interpreted in a broad sense, for example, it can be a fixed connection or a flexible connection. Detachable connection, or integral connection; it can be mechanical connection or electrical connection; it can be direct connection or indirect connection through an intermediary, and it can be the internal communication of two components. Those of ordinary skill in the art can understand the specific meanings of the above terms in the present invention based on specific situations.

The invention will be described in detail below with reference to the accompanying drawings and examples.

The production method of high-strength bolt type parts of the present invention, the produced parts are as shown in Figure 1, and it comprises the following steps:

S1: Forging the blank so that the shape of the blank is close to the part to be processed, and then fixing the forged blank on the machine tool for rough machining. The machine tool selected in the processing is a CNC lathe, and the blank is processed into a preset workpiece shape, then process the end face chamfer, and repair the blunt and sharp edges of the workpiece;

S2: Determine the total length, and cut the rough-machined blank into a predetermined length;

S3: Finishing, processing the cut blank to obtain a semi-finished product, so that the size of the semi-finished product meets the product size requirements, and at the same time rolling the rod so that the rod of the bolt forms the depression shown in Figure 1 at the preset position, specifically In other words, the size of the nut and stem of the semi-finished product conforms to the preset standard size of the part, and the size of the semi-finished product is inspected. Specifically, the rolling tool is a high-precision rolling tool with an SR-type head assembly tool, and during the machining process, the spindle speed of the machine tool is 2200r/min, the feed rate of the cutting tool is 0.08mm/r, and the cutting depth is 0.5mm; during the rolling process, the spindle speed of the lathe is 1500r/min , Feed rate: 0.2mm/r, cutting depth: 0.005mm;

S4: Roll thread, process the external thread at the predetermined position of the semi-finished product, and then heat-treat the bolt to increase the rigidity of the bolt. Specifically, how to improve the bolt strength, according to different requirements and materials, there are different heat treatment methods, which are existing technologies , I won’t go into details here, after the heat treatment is completed, it is necessary to roll the thread;

S5: Inspection: inspect the thread position through the inspection tool to determine whether the verticality of the thread meets the requirements;

S6: For parts that pass the inspection, galvanizing treatment is required.

The inspection tool is in the shape of a tube with an internal thread on its inner wall. One end surface of the inspection tool extends out of the support tube in the axial direction, and the inner wall diameter of the support tube is larger than the inner diameter of the test tool. The end faces are parallel, the internal thread of the inspection tool can be screwed with the external thread processed on the part, and the end face of the support pipe or the end surface of the inspection tool is perpendicular to the axial direction of the part. By setting the support tube at one end of the inspection tool, The end surface of the support pipe can also be pressed against the nut of the bolt, so that the inspection tool can not only inspect the bolt with full threads on the stem, but also inspect the bolt with only threads on the end far away from the nut on the stem as shown in Figure 1 , improve the scope of application of the inspection tool, and the outer diameter of the inspection tool is larger than the outer diameter of the support tube, thereby reducing the weight of the support tube and preventing the weight of the support tube from affecting the parts and the inspection tool with high precision requirements during the detection process. cause damage; the outer wall of the inspection tool is provided with anti-slip lines, and the position where the outer wall of the inspection tool is provided with anti-slip lines corresponds to the position where the internal thread is set on the inner wall of the inspection tool, so that the operator can control the inspection tool directly through the inspection tool. The thread part exerts force to make the inspection tool rotate and prevent damage to the inspection tool.

The specific detection method is that when facing a bolt covered with threads on the rod, the threaded end of the inspection tool can be brought close to the bolt, and then the inspection tool can be rotated so that the bolt is screwed with the internal thread on the inspection tool until the inspection tool The end face of the nut is tightly pressed against the nut, and the gap between the inspection tool and the nut is tested with a preset feeler gauge. If the feeler gauge cannot be inserted into the gap, the part is qualified; when the bolt shown in Figure 1 When testing, first set the support tube on the shaft of the bolt until the internal thread of the inspection tool is screwed with the external thread of the bolt, so that the nut of the bolt contacts the end face of the support tube, and then use the feeler gauge to check the screw. The gap between the cap and the support tube is tested, if the feeler gauge cannot be inserted into the gap, the part is acceptable.

In order to ensure that the processing of the inspection tool meets the requirements, it is necessary to strictly control the gap between threads. The size of the gap between threads is mainly determined by the errors of pitch diameter, pitch and tooth profile angle. Therefore, when analyzing the influence of these errors on the twisting, the tooth shape angle error and the pitch error are mainly transformed into the change relationship of the pitch diameter, which is referred to as the pitch diameter comprehensive tolerance. It consists of three parts, including the conversion of the pitch error δp The additional amount (f _p ), the additional amount converted from the profile angle error δα/2 (fα _/2 ), and the tolerance (f ₃ ) of the pitch diameter itself in manufacturing. The calculation formulas are: f _p = δpctgα/2, where δp is the maximum pitch error between any two teeth within the twisting length, α/2 is the tooth profile angle, fα _/2 = 0.582t1/sinαδα/2, where t1 is the working height of the tooth shape and the tolerance of the pitch diameter itself (f ₃ ) can be found out by looking up the national standard for common threads.

Therefore, in order to ensure good precision of thread twisting, it is necessary to fully consider the calculation of the comprehensive tolerance of the pitch diameter under the premise of ensuring the design accuracy of the original thread perpendicularity gauge. For the pitch diameter, it can be divided into simple pitch diameter and function Pitch diameter, when the thread needs to be matched, the effective pitch diameter not only exists, but also is very important. Pitch diameter of external thread: d _2w ＝d ₂ +(f _p +fα _/2 ) Pitch diameter of internal thread: D _2w ＝D ₂ -(f _p +fα _/2 ), in order to ensure good thread fit, then D _2w ≥d _2w must be satisfied, and the effective clearance of the thread tooth surface at this time is: D _2w -d _2w . This time, the runout of the end face is 0.03mm based on the thread. Based on the design principle of the gauge design manual, we also consider the important factor of D _2w -d _2w ≤ 0.03mm, so we design the thread verticality inspection tool , the tolerance value of the pitch diameter of the thread shall be set according to this principle.

The above descriptions are only preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included in the Within the scope of protection of the present invention.

Claims (8)

1. A production method of high-strength bolt parts is characterized by comprising the following steps:

s1: rough machining, namely fixing a blank on a machine tool, and machining the blank into a preset workpiece shape;

s2: setting the total length, and cutting the rough machined blank into a preset length;

s3: finish machining, namely machining the cut blank to obtain a semi-finished product, so that the size of the semi-finished product meets the size requirement of a product;

s4: rolling threads, and processing external threads at a preset position of the semi-finished product;

s5: and (4) checking: inspecting the position of the thread through the inspection tool;

the inspection device is tubular, an internal thread is formed in the inner wall of the inspection device, a supporting tube extends from the end face of one end of the inspection device in the axial direction, the diameter of the inner wall of the supporting tube is larger than the inner diameter of the inspection device, the end face of the supporting tube is parallel to the end face of the inspection device, the internal thread of the inspection device can be in threaded connection with an external thread machined on a part, and the end face of the supporting tube or the end face of the inspection device is perpendicular to the axial direction of the part.

2. The method for producing a high-strength bolt part according to claim 1, wherein: after finishing, a predetermined portion of the workpiece needs to be roll-processed using a rolling cutter of the SR-type head assembly.

3. The method for producing a high-strength bolt part according to claim 1, wherein: and after the rough turning process, blunting the sharp edge of the chamfer of the workpiece.

4. The method for producing a high-strength bolt part according to claim 1, wherein: after thread machining, the workpiece needs to be heat treated to improve the rigidity of the workpiece and to be rolled after heat treatment.

5. The method for producing a high-strength bolt part according to claim 1, wherein: in the finish machining process, the rotating speed of a main shaft of the machine tool is 2200r/min, the feed amount of a cutting tool is 0.08mm/r, and the cutting depth is 0.5mm.

6. The method for producing a high-strength bolt-like part according to claim 2, wherein: in the working process of the rolling cutter, the rotating speed of a main shaft of a lathe is 1500r/min, and the feeding amount is as follows: 0.2mm/r, depth of cut: 0.005mm.

7. The method for producing a high-strength bolt part according to claim 1, wherein: the outer diameter of the checking fixture is larger than that of the supporting tube.

8. The method for producing a high-strength bolt part according to claim 1, wherein: the outer wall of the checking fixture is provided with anti-slip lines, and the position of the outer wall of the checking fixture, which is provided with the anti-slip lines, corresponds to the position of the inner wall of the checking fixture, which is provided with the internal thread.

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