Bolt machining device based on hexagonal hole bottom conical surface positioning
By using a bolt processing device based on the hexagonal hole bottom conical surface for positioning, and combining a 118° conical tip with an adjustable pin, the problems of datum non-coincidence error and stress concentration in the processing of internal hexagonal bolts are solved, achieving high-precision, low-stress, and efficient mass production.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANNXI DIESEL ENGINE HEAVY IND
- Filing Date
- 2025-05-08
- Publication Date
- 2026-05-15
AI Technical Summary
Existing technologies cannot simultaneously meet the requirements of high precision, low stress, and mass production for machining internal hexagonal bolts, resulting in issues such as datum misalignment error and stress concentration.
A bolt processing device based on hexagonal hole bottom conical surface positioning is adopted. It uses a combination of 118° conical tip and adjustable pin to directly position the internal hexagonal hole bottom conical surface as the reference, eliminating reference conversion error and is compatible with lathes, grinding machines and thread rolling machines.
It achieves high-precision positioning, eliminates reference conversion errors, improves the accuracy and efficiency of mass production, maintains the mechanical properties of parts, reduces processing stress, and improves the fatigue life of parts.
Smart Images
Figure CN224238917U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of mechanical processing technology, specifically relating to a bolt processing device based on the hexagonal hole bottom conical surface positioning, and more particularly to a positioning device for processing high-precision internal hexagonal bolts, applicable to lathes, grinding machines and thread rolling machines, etc., to achieve precise positioning processing based on the hexagonal hole bottom conical surface. Background Technology
[0002] Marine diesel engine fasteners include various types of hexagonal bolts (the hexagonal end cannot be machined with a center hole). The hexagonal head face and thread have dimensional and positional tolerance requirements relative to the part's axis, such as... Figure 6 As shown, grinding, precision turning, or thread rolling must be performed with the axis as the reference. There are currently two methods for machining the end face and outer diameter of internal hexagonal bolts:
[0003] Option 1: After datum conversion, the outer diameter of the head is machined based on the hexagonal datum. Then, the head circle is clamped and the end face, shank and thread outer diameter are machined. Finally, the thread is rolled based on the thread rolling outer diameter.
[0004] Option 2: Use the center holes at both ends to locate and machine the end face, outer circle, and thread, and finally use the outer circle of the head as a reference to machine the internal hexagon.
[0005] Defects of existing processing methods:
[0006] The drawbacks of Option 1 are: Multiple datum conversions result in datum non-coincidence errors; during thread rolling, the outer diameter of the thread before rolling is used for positioning. Due to the difference between the diameter before rolling and the major diameter of the thread, coupled with the natural sag of the part head, the thread centerline will inevitably have a certain tilt error with the part's axis during rolling. This option poses a certain quality risk in the machining of high-precision bolts.
[0007] The drawbacks of Option Two: While using center holes at both ends for positioning and machining the end face, outer diameter, and threads ensures the accuracy of these components, stamping the hexagonal internal structure results in significant internal stress. This stress increases with the part's strength, impacting its performance and lifespan—a fatal flaw for parts requiring high reliability. Electrolytic machining creates a porous layer on the inner wall of the hexagonal internal structure, affecting its strength and posing a disadvantage in high-strength bolt production. Furthermore, electrolytic machining severely reduces processing efficiency, hindering mass production.
[0008] Therefore, existing technologies cannot simultaneously meet the requirements of high precision, low stress, and mass production. There is an urgent need for a device that can directly position the device using the conical surface of the bottom of the internal hexagonal hole, eliminating datum errors and simplifying the process. Utility Model Content
[0009] The technical problem solved by this utility model is to provide a bolt processing device based on the positioning of the bottom conical surface of a hexagonal hole. This utility model solves the problems of non-coincidence of datum, stress concentration and low efficiency in the processing of internal hexagonal bolts.
[0010] To achieve the above objectives, the technical solution adopted by this utility model is as follows:
[0011] A bolt processing device based on hexagonal hole bottom conical surface positioning includes:
[0012] A conical positioning component has a conical tip at its head, the angle of which is consistent with the bottom conical surface of the hexagonal hole of the hexagonal bolt. The conical tip is integrally connected to the positioning component rod, the diameter of which is smaller than the diameter of the inscribed circle of the hexagonal hole. The rear end of the positioning component rod is coaxially connected to the positioning component clamping shank for fixing to the machine tool spindle or tailstock.
[0013] The pin is detachably installed on the side wall of the conical positioning component and inserted into the hexagonal hole of the internal hexagonal bolt to restrict the degree of rotational freedom.
[0014] As a further limitation of the above scheme, the cone-shaped positioning component has a cone tip of 118°.
[0015] As a further limitation of the above scheme, the gap between the pin and the inner wall of the hexagonal hole of the internal hexagonal bolt is 0.1 to 0.2 mm.
[0016] Further defining the above scheme, the diameter of the positioning rod of the conical positioning component is 0.5 to 1 mm smaller than the diameter of the inscribed circle of the hexagonal hole of the internal hexagonal bolt.
[0017] As a further limitation of the above scheme, the pin is a cylindrical pin, and its length can be changed according to the size of the hexagonal hole.
[0018] Further defining the above solution, the device is compatible with lathes, grinding machines, or thread rolling machines, and equipment compatibility is achieved by replacing the positioning clamping shank.
[0019] Further defining the above solution, when used in a grinding machine, the conical positioning element is replaced with a modified grinding machine tip, retaining the 118° conical structure.
[0020] Advantages of this utility model compared to the prior art:
[0021] 1. This solution is a hexagonal hole bottom conical surface positioning device. Through the combination of a 118° conical surface positioning component and an adjustable pin, it achieves high-precision machining of internal hexagonal bolts, eliminates datum conversion errors, is compatible with various machine tools, and significantly improves the accuracy and efficiency of mass production.
[0022] 2. This solution features high-precision positioning: using hexagonal positioning eliminates the accumulation of errors caused by part datum conversion, and ensures that the design datum and machining datum coincide, thus eliminating datum misalignment errors and helping to guarantee part accuracy.
[0023] 3. Stress control in this solution: The internal hexagonal machining can be completed in the roughing stage, and no more machining stress will be generated from the semi-finishing stage onwards, which helps to maintain the mechanical properties of the parts and improve their fatigue life.
[0024] 4. This solution is highly versatile: the same device can be adapted to multiple processes such as turning, grinding, and rolling, increasing batch production efficiency by 30%;
[0025] 5. This solution offers low-cost modification: the tooling and equipment used are low-cost to manufacture, requiring only minor modifications to existing equipment, resulting in low modification costs.
[0026] 6. The parts in this solution are positioned by the axis, making machine tool adjustment convenient, the processing solution is simple and reliable, and it is conducive to mass production. Attached Figure Description
[0027] Figure 1 This is a front view of the overall structure of this utility model;
[0028] Figure 2 This utility model Figure 1 Sectional view along axis AA;
[0029] Figure 3 This is an exploded structural diagram of the present invention;
[0030] Figure 4 This is a schematic diagram of the modified positioning component for the grinding machine in this utility model;
[0031] Figure 5 This is a schematic diagram of the modified positioning component of the thread rolling machine in this utility model.
[0032] Figure 6 This is a front view of the internal hexagonal bolt being processed in this utility model;
[0033] Figure 7 This is a left view of the internal hexagonal bolt being processed in this utility model. Detailed Implementation
[0034] The technical solutions of the present utility model will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present utility model, and not all embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present utility model.
[0035] In the description of this utility model, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model.
[0036] It should be noted that, in this document, the terms "comprising," "including," or any other variations thereof are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.
[0037] Please see Figure 1-7 The embodiments of this utility model are described in detail below.
[0038] Example: See Figure 1-3 As shown, a bolt processing device based on hexagonal hole bottom conical surface positioning includes: a conical positioning component 1, the head of which is a conical tip 1-1, the conical tip 1-1 having the same angle as the conical surface 3-1 of the hexagonal hole bottom of the internal hexagonal bolt 3, preferably a 118° conical surface in this embodiment; the conical tip 1-1 is integrally connected to a positioning component rod 1-2, the diameter of the positioning component rod 1-2 being smaller than the diameter of the inscribed circle of the hexagonal hole; the rear end of the positioning component rod 1-2 is coaxially connected to a positioning component clamping handle 1-3 for fixing to the machine tool spindle or tailstock and transmitting torque. A pin 2 is detachably installed on the side wall of the conical positioning component 1 and inserted into the hexagonal hole of the internal hexagonal bolt 3 to restrict rotational freedom.
[0039] This invention uses hexagonal positioning to eliminate the accumulation of errors caused by part datum conversion, and ensures that the design datum and the machining datum coincide, thus eliminating the error caused by datum misalignment and helping to guarantee the accuracy of the parts.
[0040] Preferably, the gap between the pin 2 and the inner wall of the hexagonal hole of the internal hexagonal bolt 3 is 0.1 to 0.2 mm, which can be adapted to different tolerance requirements and is specifically set according to the form and position tolerance requirements of the parts.
[0041] Preferably, the diameter of the positioning rod 1-2 of the conical positioning member 1 is 0.5 to 1 mm smaller than the diameter of the inscribed circle of the hexagonal hole of the internal hexagonal bolt 3.
[0042] Preferably, the pin 2 is a cylindrical pin, and its length can be changed according to the size of the hexagonal hole.
[0043] This device is compatible with lathes, grinding machines or thread rolling machines. Equipment compatibility can be achieved by replacing the positioning clamping handles 1-3.
[0044] Modify the centers of grinding machines and thread rolling machines, changing their original 60° conical surface to a 118° conical surface. Determine the diameter of the shank based on the size of the internal hexagonal shape, ensuring no interference. Fabricate the positioning clamping shanks 1-3 as Morse III or Morse II taper shanks. Grinding machine positioning components such as... Figure 4 As shown, the positioning component of the thread rolling machine is as follows: Figure 5 As shown.
[0045] The following explanation uses the S14 internal hex bolt as an example to illustrate its usage:
[0046] Lathe machining: After the internal hexagonal shape of the internal hexagonal bolt 3 is formed, the semi-finishing of the part is carried out. The conical positioning component 1 is installed on the lathe spindle. The conical surface at the bottom of the internal hexagonal hole of the internal hexagonal bolt 3 is used as the positioning reference. The 118° conical tip 1-1 fits against the bottom of the hexagonal hole. The pin 2 is inserted into the hole wall on either side. The positioning component clamping handle 1-3 is driven to rotate to machine the outer circle and end face.
[0047] Grinding machine / thread rolling machine: Replace the corresponding positioning parts to maintain the same reference and complete the fine grinding and thread rolling.
[0048] This invention achieves high-precision machining of hexagonal bolts by combining a conical positioning component with an adjustable pin, eliminating datum conversion errors, adapting to various machine tools, and significantly improving the accuracy and efficiency of mass production.
[0049] It will be apparent to those skilled in the art that this invention is not limited to the details of the exemplary embodiments described above, and that it can be implemented in other specific forms without departing from the spirit or essential characteristics of this invention. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of this invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of equivalents of the claims be included within this invention. No reference numerals in the claims should be construed as limiting the scope of the claims.
[0050] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.
Claims
1. A bolt processing device based on hexagonal hole bottom conical surface positioning, characterized in that: include: A conical positioning component (1) has a conical tip (1-1) at its head. The angle of the conical tip (1-1) is consistent with the bottom conical surface (3-1) of the hexagonal hole of the internal hexagonal bolt (3). The conical tip (1-1) is integrally connected to the positioning component rod (1-2). The diameter of the positioning component rod (1-2) is smaller than the diameter of the inscribed circle of the hexagonal hole. The rear end of the positioning component rod (1-2) is coaxially connected to the positioning component clamping handle (1-3) for fixing to the machine tool spindle or tailstock. The pin (2) is detachably installed on the side wall of the conical positioning part (1) and inserted into the hexagonal hole of the internal hexagonal bolt (3) to restrict the degree of rotational freedom.
2. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 1, characterized in that: The cone-shaped positioning component (1) has a cone tip (1-1) of 118°.
3. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 1, characterized in that: The gap between the pin (2) and the inner wall of the hexagonal hole of the internal hexagonal bolt (3) is 0.1 to 0.2 mm.
4. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 1, characterized in that: The diameter of the positioning rod (1-2) of the conical positioning component (1) is 0.5-1 mm smaller than the diameter of the inscribed circle of the hexagonal hole of the internal hexagonal bolt (3).
5. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 1, characterized in that: The pin (2) is a cylindrical pin, and its length can be changed according to the size of the hexagonal hole.
6. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 1, characterized in that: This device is compatible with lathes, grinding machines or thread rolling machines, and compatibility is achieved by changing the positioning clamping handle (1-3).
7. The bolt processing device based on hexagonal hole bottom conical surface positioning according to claim 6, characterized in that: When used in a grinding machine, the conical positioning element (1) is replaced with a modified grinding machine tip, retaining the 118° conical structure.