Eccentric bolt and processing method thereof

Abstract

The present invention relates to the field of eccentric bolts, and specifically to an eccentric bolt and a processing method thereof, comprising a bolt body and a gasket arranged on the bolt body; the bolt body comprises a screw rod and a nut arranged at the end of the screw rod; an anti-rotation boss is arranged at one end of the screw rod close to the nut; the gasket is sleeved on the anti-rotation boss; a positioning groove is arranged at one end of the screw rod away from the nut; the horizontal projection of the anti-rotation boss is polygonal; the eccentric bolt disclosed in the present invention changes the traditional eccentric bolt structure, and the present invention can ensure the stability of the placement and arrangement of the gasket on the screw rod body through the provision of the anti-rotation boss, thereby avoiding the rotation of the gasket on the bolt body.

Description

Technical Field

[0001] The invention relates to the field of eccentric bolts, in particular to an eccentric bolt and a processing method thereof. Background Art

[0002] The eccentric bolts for adjusting the four-wheel alignment of passenger cars, as part of the automobile suspension system, are used for adjusting the four-wheel alignment and are essential for maintaining the correct positioning of the wheels.

[0003] The eccentric bolts used for adjusting the four-wheel alignment of passenger cars are mainly used to adjust the toe-in, camber and other angles of the wheels to ensure that the contact between the wheels and the ground is in the best state.

[0004] Correct four-wheel alignment can improve the vehicle's handling and driving stability, reduce tire wear and improve driving safety.

[0005] The existing eccentric bolts mainly include screws and washers. The traditional connection method between the washers and the screws mostly adopts straight lines for interference fit connection. The traditional connection method is relatively simple and not stable enough. In addition, the interference fit between the straight lines and the washers is small, and the washers are easy to shake or move on the screws.

[0006] At the same time, when producing eccentric bolts with traditional production processes, there are many production steps and processes, and when opening the positioning groove on the eccentric bolt, the traditional opening method is mostly grinding. The grinding process has low production efficiency and is not conducive to speeding up the processing efficiency of the eccentric bolt.

[0007] In addition, the existing production process performs heat treatment before thread rolling, which increases the strength of the bolt itself and affects the service life of the thread rolling plate.

[0008] The existing patent 201820924549.3 - Eccentric bolt assembly and vehicle having the same does not clearly disclose the technical problem of solving the above-mentioned problem.

[0009] Therefore, in order to improve or solve at least one of the above problems, it is necessary to improve the existing eccentric bolts or the production equipment or process of eccentric bolts. Summary of the invention

[0010] The purpose of the invention is to provide an eccentric bolt structure which can ensure stable assembly of a gasket on a screw rod.

[0011] In order to achieve the above object, the technical solution adopted by the present invention is:

[0012] An eccentric bolt comprises a bolt body and a gasket arranged on the bolt body;

[0013] The bolt body comprises a screw rod and a nut arranged at the end of the screw rod; an anti-rotation boss is arranged at one end of the screw rod close to the nut; and the gasket is sleeved on the anti-rotation boss;

[0014] A positioning groove is arranged at one end of the screw rod away from the nut.

[0015] The horizontal projection of the anti-rotation boss is polygonal.

[0016] The edges on the anti-rotation boss and the edges on the nut are staggered.

[0017] A method for processing an eccentric bolt, the method comprising the following steps:

[0018] Step 1: Material modification: modify the metallographic structure, grain size, strength and size of the raw materials to meet the requirements of cold extrusion of bolts to form a blank;

[0019] Step 2: Main body forming: The bolt body is formed by cold heading process;

[0020] Step 3: rolling the thread; forming a thread section on the bolt body;

[0021] Step 4: Opening a positioning groove: Opening a positioning groove on the bolt body by milling process;

[0022] Step 5: Install the gasket; the gasket is assembled on the bolt body by riveting process;

[0023] Step 6: Appearance selection;

[0024] Step 7: Pack the eccentric bolts selected in step 6 and put them into storage.

[0025] The cold heading process in step 2 includes the following steps:

[0026] S1: Preliminary upsetting: the blank is preliminarily upset to form the preliminary shape of the eccentric bolt; and the nut and anti-rotation boss are preliminarily formed;

[0027] S2: Preforming: The blank after initial upsetting is further preformed to make it closer to the final shape to form a preformed blank;

[0028] S3: Fine upsetting: Fine upsetting is performed on the preformed blank to form the required bolt body.

[0029] In the step 4, it is required to realize the opening processing of the positioning groove on the bolt body by using processing equipment.

[0030] In step 5, a riveting die is required to be used to install the gasket on the bolt body.

[0031] The riveting die comprises a die body, an axial positioning hole is arranged on the die body, and an annular flange is arranged at the edge of the axial positioning hole; when in use, the anti-rotation protrusion is squeezed by the annular flange on the riveting die to achieve a fixed connection between the gasket and the bolt body.

[0032] Before starting step 3, oil removal operation needs to be performed first.

[0033] After step 4 and before step 5, the bolt body needs to be heat treated.

[0034] The advantages of the present invention are:

[0035] The invention discloses an eccentric bolt and a processing method thereof.

[0036] The eccentric bolt disclosed in the present invention changes the traditional eccentric bolt structure. The present invention can ensure the stability of the placement of the gasket on the screw body and avoid the rotation of the gasket on the bolt body by setting the anti-rotation boss.

[0037] The present invention can improve the production efficiency of the eccentric bolts and ensure the processing quality of the eccentric bolts by disclosing the specific processing procedures. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] The following is a brief description of the contents expressed in the drawings of the present invention and the symbols in the drawings:

[0039] Figure 1 It is a schematic diagram of the structure of the present invention.

[0040] Figure 2 It is a structural schematic diagram of the anti-rotation boss in the present invention.

[0041] Figure 3 It is a side view of the anti-rotation boss in the present invention.

[0042] Figure 4 It is a schematic diagram of the structure of the riveting die in the present invention when in use.

[0043] The marks in the above figure are:

[0044] 1. Bolt body, 11. Nut, 12. Screw, 13. Anti-rotation boss, 3. Positioning groove, 4. Riveting die. DETAILED DESCRIPTION

[0045] The specific implementation of the present invention will be further explained in detail below by describing the optimal embodiment with reference to the accompanying drawings.

[0046] An eccentric bolt comprises a bolt body 1 and a gasket 2 arranged on the bolt body 1; the bolt body 1 comprises a screw rod 12 and a nut 11 arranged at the end of the screw rod 12; an anti-rotation boss 13 is provided at one end of the screw rod 12 close to the nut 11; the gasket 2 is sleeved on the anti-rotation boss 13; a positioning groove 3 is provided at one end of the screw rod 12 away from the nut 11; the eccentric bolt disclosed in the present invention changes the traditional eccentric bolt structure, and the present invention can ensure the stability of the placement of the gasket 2 on the screw rod 12 body through the provision of the anti-rotation boss 13, thereby preventing the gasket 2 from rotating on the bolt body 1.

[0047] At the same time, in the present invention, the anti-rotation boss 13 is located at the connection between the nut 11 and the screw rod 12 . Such a configuration can well ensure the structural strength of the connection between the nut 11 and the screw rod 12 .

[0048] In actual use, the anti-rotation boss 13 is connected to the gasket 2 by means of interference fit, which greatly facilitates the installation and fixation of the gasket 2 on the bolt body 1 .

[0049] Furthermore, the horizontal projection of the anti-rotation boss 13 in the present invention is polygonal; generally, the anti-rotation boss 13 is a regular hexagonal prism structure; at the same time, in order to facilitate assembly and use of assembly operations, the present invention requires that a hexagonal hole is also provided on the gasket 2; the problem of the traditional weak connection through straight lines is changed.

[0050] At the same time, the edges on the anti-rotation boss 13 and the edges on the nut 11 are staggered; based on this design, the present invention avoids the overlap of the edges on the anti-rotation boss 13 and the nut 11, and avoids stress concentration and breakage at the flange of the nut 11 during subsequent cold heading.

[0051] In the present invention, the anti-rotation boss 13 and the nut 11 are both similar to a hexagonal prism structure; it is required that the corners of the two hexagonal prism structures are staggered.

[0052] The eccentric bolt in the present invention is mainly an eccentric bolt used for adjusting the four-wheel alignment of a passenger car.

[0053] At the same time, the gasket is used in combination with the bolt body.

[0054] In the present invention, the nut is a hexagonal flange head; the screw rod is provided with an anti-rotation boss near the root of the hexagonal normal head; the gasket is sleeved on the anti-rotation boss; and the threaded end of the screw rod is provided with a positioning groove.

[0055] A method for processing an eccentric bolt, the method comprising the following steps:

[0056] Step 1: Material modification: modify the metallographic structure, grain size, strength and size of the raw materials to meet the requirements of cold extrusion of bolts to form a blank;

[0057] Step 2: Main body forming: The bolt body 1 is formed by cold heading process;

[0058] Step 3: rolling the thread; forming a thread segment on the bolt body 1;

[0059] Step 4: Opening a positioning groove 3: Opening a positioning groove 3 on the bolt body 1 by a milling process;

[0060] Step 5: Install the gasket 2; the gasket 2 is assembled on the bolt body 1 by riveting process;

[0061] Step 6: Appearance selection;

[0062] Step 7: Pack the eccentric bolts selected in step 6 and put them into storage.

[0063] Based on the disclosure of the above processing method, the present invention can realize the production and processing of eccentric bolts.

[0064] The processing method disclosed in the present invention specifically comprises the following steps:

[0065] Step 1: Material modification: modify the metallographic structure, grain size, strength and size of the raw materials to meet the requirements of cold extrusion forming of bolts to form blanks; this step ensures that the raw materials meet the requirements of subsequent processing and lays the foundation for the forming of eccentric bolts;

[0066] Step 2: forming the main body; forming the bolt body 1 by cold heading process; forming the bolt body 1 by cold heading process; the cold heading process can plastically deform the metal in a cold state to form the basic shape of the bolt, such as the nut 11 and the rod, while improving the mechanical properties of the material;

[0067] Step 3: degreasing; degreasing the bolt body 1 formed in step 2; removing oil stains and impurities on the bolt surface to provide a clean surface for subsequent processing and treatment, and preventing oil stains from affecting the adhesion of subsequent coatings or causing processing quality problems;

[0068] Step 4: thread rolling; forming a thread segment on the bolt body 1; forming a thread segment on the bolt body 1; thread rolling is a key step in bolt processing, and threads are processed on the bolt shank through a thread rolling plate or a die so that it can be used in conjunction with other threaded connectors;

[0069] Step 5: Opening a positioning groove 3; Opening a positioning groove 3 on the bolt body 1 by a milling process; Opening a positioning groove 3 on the bolt body 1 by a milling process; The positioning groove 3 is used to ensure the correct position of the bolt during assembly, and is sometimes also used to install a gasket 2 or other accessories;

[0070] Step 6: Heat treatment; the heat treatment here is mainly dephosphorization and heat treatment; remove the phosphating layer on the surface of the bolt and perform heat treatment to improve the mechanical properties of the material, such as hardness and toughness. At the same time, removing the phosphating layer on the surface can prevent corrosion and improve the adhesion of the coating;

[0071] Step 7: Flaw detection and demagnetization: Flaw detection is used to check for defects inside the bolts to ensure product quality; demagnetization is used to remove the magnetism generated by the bolts during processing to prevent the absorption of impurities such as iron filings during subsequent use;

[0072] Step 8: Install the gasket 2; the gasket 2 is assembled on the bolt body 1 by a riveting process; the gasket 2 is assembled on the bolt body 1 by a riveting process; the use of the gasket 2 can improve the sealing performance of the bolt and prevent liquid or gas leakage;

[0073] Step 9: Protective layer coating; mainly zinc-aluminum coating here: a zinc-aluminum layer is coated on the surface of the bolt to provide a stable friction coefficient coating and anti-corrosion protection, improve the reliability of vehicle assembly and extend the service life of the bolt; the comprehensive friction coefficient of the coating ranges from μ = 0.09 to 0.15.

[0074] Step 10: Appearance selection: Check the appearance of the bolts to remove defective products and ensure the appearance quality of the final product;

[0075] Step 11: Pack the eccentric bolts selected in step 10 and store them in warehouse; pack the qualified bolts for easy transportation and storage, and store them in the warehouse for shipment or further use.

[0076] Furthermore, the cold heading process in step 2 of the present invention includes the following steps:

[0077] S1: Preliminary upsetting: Preliminary upsetting of the blank to form the preliminary shape of the eccentric bolt; and preliminary formation of the nut 11 and the anti-rotation boss 13;

[0078] S2: Preforming: The blank after initial upsetting is further preformed to make it closer to the final shape to form a preformed blank;

[0079] S3: Fine upsetting: Fine upsetting is performed on the preformed blank to form the required bolt body 1.

[0080] In the present invention, the initial upsetting (S1) has the following functions: to perform preliminary upsetting on the blank, which is the first step of the cold upsetting process; at this stage, the blank is compressed and formed to form the preliminary shape of the eccentric bolt; at the same time, the nut 11 and the anti-rotation boss 13 are initially formed to lay the foundation for subsequent processing; purpose: to ensure that the basic shape and size of the blank meet the design requirements and to prepare for the preforming and fine upsetting stages.

[0081] Preforming (S2) Function: To further preform the blank after initial upsetting to make it closer to the final shape; at this stage, the shape and size of the blank are further adjusted to ensure that it matches the shape and function of the final product; Purpose: Through preforming, the amount of deformation required in the fine upsetting stage can be reduced, thereby reducing stress and material waste during processing and improving production efficiency.

[0082] Fine upsetting (S3) Function: Fine upsetting the preformed blank to form the required bolt body 1. At this stage, the blank is accurately formed into the shape of the final product, including the head, shank and threaded part (if necessary); Purpose: To ensure that the size, shape and mechanical properties of the bolt fully meet the design and use requirements, and prepare for subsequent thread processing and surface treatment.

[0083] Furthermore, the present invention requires that the positioning groove 3 be opened on the bolt body 1 by means of processing equipment; the present invention uses the processing equipment to open the positioning groove 3 by means of a milling process; this changes the trouble of the traditional processing method of using grinding to produce and process the positioning groove 3, and at the same time, the opening of the positioning groove 3 is achieved by means of a milling process, which can ensure the opening accuracy of the positioning groove 3; and at the same time, avoid curling or burrs at the edge of the positioning groove 3.

[0084] Furthermore, in step 5 described in the present invention, it is required to use a riveting die 4 to realize the installation of the gasket 2 on the bolt body 1; the present invention facilitates the fixed installation of the gasket 2 on the bolt body 1 through the setting of the riveting die 4; at the same time, in actual use, it is required to extrude the anti-rotation protrusion through the riveting die 4, so that the anti-rotation protrusion is deformed, thereby realizing the extrusion and fixation of the gasket 2; facilitating the fixed installation of the gasket 2 on the bolt body 1.

[0085] Furthermore, in the present invention, the riveting die 4 includes a die body 41, an axial positioning hole 42 is provided on the die body 41, and an annular flange 43 is provided at the edge of the axial positioning hole 42; when in use, the anti-rotation protrusion is squeezed by the annular flange 43 on the riveting die 4 to achieve a fixed connection between the gasket 2 and the bolt body 1; in the present invention, the die body 41 is the main structure of the riveting die 4, and the setting of the axial positioning hole 42 plays a good avoidance role, thereby preventing the interference between the bolt body 1 and the riveting die 4 when the gasket 2 is riveted; and the annular flange 43 acts as an external protrusion, and in subsequent use, the annular flange 43 squeezes the anti-rotation protrusion, causing the anti-rotation protrusion to deform, thereby achieving the extrusion and fixation of the gasket 2; it facilitates the fixed installation of the gasket 2 on the bolt body 1.

[0086] Furthermore, before starting step 3 described in the present invention, a degreasing operation needs to be performed first; oil stains and impurities on the surface of the bolt are removed to provide a clean surface for subsequent processing and treatment, and to prevent oil stains from affecting the adhesion of subsequent coatings or causing processing quality problems.

[0087] Furthermore, after the step 4 in the present invention is completed and before the step 5 is started, the bolt body 1 needs to be heat treated; the phosphating layer on the surface of the bolt is removed and heat treated to improve the mechanical properties of the material, such as hardness and toughness. At the same time, removing the phosphating layer on the surface can prevent corrosion and improve the adhesion of the coating.

[0088] At the same time, the present invention requires that the heat treatment process be carried out between the positioning groove 3 opening process and the gasket 2 installation process. Such a setting can avoid the excessive strength of the bolt body 1 caused by early heat treatment, which may cause damage to the thread rolling plate or the tool structure during the thread rolling process or the positioning groove 3 opening process. It is required to be carried out before the gasket 2 installation process to avoid the bolt body 1 being too low in strength and damaged during subsequent riveting.

[0089] In addition, in step 4 of the present invention: opening a positioning groove 3; opening the positioning groove 3 on the bolt body 1 by a milling process; based on this design, the following advantages are specifically achieved: first, the slotting efficiency is improved: milling generally has higher production efficiency because it can quickly remove a large amount of material; in addition, the surface finish of the positioning groove 3 is better: milling can select the design and number of grooves to achieve the best surface finish, thereby minimizing the need for subsequent finishing processes.

[0090] At the same time, the milling and grooving operations of multiple eccentric bolts can be realized at one time in conjunction with processing equipment.

[0091] In the present invention, step 5: installing the gasket 2; the gasket 2 is assembled on the bolt body 1 by a riveting process; based on this design, the installation and fixation between the gasket 2 and the bolt body 1 is facilitated.

[0092] The processing equipment comprises a machine body; a workbench and a tool structure are arranged on the machine body; the tool structure is located above the workbench; and a placement device for placing a bolt body 1 to be processed is arranged on the workbench.

[0093] The tool structure described in the present invention includes a rough milling cutter and a fine milling cutter; the processing equipment disclosed in the present invention can better realize the milling operation on the bolt body 1 through the coordinated use of the rough milling cutter and the fine milling cutter, and finally form a positioning groove 3 structure. At the same time, in the present invention, the outer diameter of the shank of the rough milling cutter described in the present invention is larger than the outer diameter of the shank of the fine milling cutter; based on such a setting, the service life of the tool structure can be well guaranteed.

[0094] When used specifically, the workpiece to be processed is clamped: a corresponding number of bolt bodies 1 to be milled are placed on a placing device of a processing device.

[0095] This step ensures that all workpieces are properly secured for subsequent milling operations.

[0096] Rough milling: The bolt body 1 to be milled on the placement device is milled using a rough milling cutter. The purpose of rough milling is to quickly remove a large amount of material in preparation for fine milling; the rough milling cutter is usually of larger size to increase the material removal rate.

[0097] Finishing milling: After the rough milling is completed, the bolt body 1 to be milled on the placement device is milled using a finishing milling cutter; the purpose of finishing milling is to obtain a machined surface with higher precision and surface finish; the finishing milling cutter usually has a smaller pitch and a sharper cutting edge.

[0098] Machining completion and repeated operation: After fine milling is completed, the machining operation of the positioning grooves 3 of each bolt body 1 on the placement device is completed; if it is necessary to machine the positioning grooves 3 on other bolt bodies 1, just repeat the above steps.

[0099] The above process can ensure that the positioning groove 3 on the bolt body 1 is processed to achieve the required accuracy and quality.

[0100] In actual operation, the following points should also be noted: Tool selection: Select appropriate roughing and finishing cutters according to the hardness of the material and processing requirements.

[0101] Milling parameters: Set appropriate cutting speed, feed rate and cutting depth to ensure processing efficiency and surface quality; Coolant: Use coolant during milling to reduce cutting temperature, extend tool life and improve processing surface quality.

[0102] Furthermore, in step 2 and step 3 described in the present invention, a rough milling cutter is required to perform three rough milling operations on each bolt body 1; and a fine milling cutter is used to perform one fine milling operation on each bolt body 1; the purpose of using a rough milling cutter to perform three rough milling operations on each bolt body 1 is mainly to quickly remove a large amount of material in preparation for subsequent fine processing.

[0103] During rough milling, the cutting depth of the tool is large and the feed speed is fast, but the machining accuracy and surface quality are relatively low.

[0104] The main purpose of rough milling is to quickly remove a large amount of material from the workpiece. This step is not precise, but it is very fast. By performing the rough milling process, the workload of the next finishing process is reduced.

[0105] The purpose of using a fine milling cutter to perform a fine milling operation on each bolt body 1 is to meet the precision requirements of part processing and provide high-quality surface finish and precise dimensions.

[0106] Finishing milling cutters usually have sharper cutting edges and higher tool strength, reducing tool making tools, reducing the problem of taper in side milling, and improving the quality of finishing surface.

[0107] Finish milling produces a smoother cut, resulting in a better surface finish.

[0108] Obviously, the specific implementation of the present invention is not limited to the above-mentioned methods. As long as various non-substantial improvements are made using the method concept and technical solution of the present invention, they are all within the protection scope of the present invention.

Claims

1. An eccentric bolt, characterized in that: It comprises a bolt body and a gasket arranged on the bolt body; the bolt body comprises a screw rod and a nut arranged at the end of the screw rod; an anti-rotation boss is arranged at one end of the screw rod close to the nut; the gasket is sleeved on the anti-rotation boss; A positioning groove is arranged at one end of the screw rod away from the nut.

2. An eccentric bolt according to claim 1, characterized in that: The horizontal projection of the anti-rotation boss is polygonal.

3. The eccentric bolt according to claim 1, characterized in that: The edges on the anti-rotation boss and the edges on the nut are staggered.

4. A method for processing an eccentric bolt, characterized in that: The processing method comprises the following steps: Step 1: Material modification: modify the metallographic structure, grain size, strength and size of the raw materials to meet the requirements of cold extrusion of bolts; Step 2: Main body forming: The bolt body is formed by cold heading process; Step 3: rolling the thread; forming a thread section on the bolt body; Step 4: Opening a positioning groove: Opening a positioning groove on the bolt body by milling process; Step 5: Install the gasket; the gasket is assembled on the bolt body by riveting process; Step 6: Appearance selection; Step 7: Pack the eccentric bolts selected in step 6 and put them into storage.

5. The method for processing an eccentric bolt according to claim 4, characterized in that: The cold heading process in step 2 includes the following steps: S1: Preliminary upsetting: the blank is preliminarily upset to form the preliminary shape of the eccentric bolt; and the nut and anti-rotation boss are preliminarily formed; S2: Preforming: The blank after initial upsetting is further preformed to make it closer to the final shape to form a preformed blank; S3: Fine upsetting: Fine upsetting is performed on the preformed blank to form the required bolt body.

6. The method for processing an eccentric bolt according to claim 4, characterized in that: In the step 4, it is required to realize the opening processing of the positioning groove on the bolt body by using processing equipment.

7. The method for processing an eccentric bolt according to claim 4, characterized in that: In step 5, a riveting die is required to be used to install the gasket on the bolt body.

8. The method for processing an eccentric bolt according to claim 7, characterized in that: The riveting die comprises a die body, an axial positioning hole is arranged on the die body, and an annular flange is arranged at the edge of the axial positioning hole; when in use, the anti-rotation protrusion is squeezed by the annular flange on the riveting die to achieve a fixed connection between the gasket and the bolt body.

9. The method for processing an eccentric bolt according to claim 4, characterized in that: Before starting step 3, oil removal operation needs to be performed first.

10. The method for processing an eccentric bolt according to claim 4, characterized in that: After step 4 and before step 5, the bolt body needs to be heat treated.

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