Variable-diameter self-positioning cold working press riveting jig

Abstract

This utility model proposes a cold-working riveting fixture with variable diameter and self-positioning function, comprising: an upper plate (1), a guide post (2), a punch seat (3), a fixing sleeve (4), a punch (5), a guide sleeve (6), a base plate (7), a die seat (8), a fixing bolt (9), a pressure plate (10), and a clamping nut (11). The upper plate (1) and the guide post (2) are interference-fitted; the upper plate (1) and the punch seat (3) are clearance-fitted; the fixing sleeve (4) loads the punch (5) and transmits the equipment loading pressure to the punch (5); the upper plate (1) and the base plate (7) of the fixture are slidably fitted through the guide post (2) and the guide sleeve (6); the die seat (8) and the base plate (7) are assembled to achieve automatic centering, and the fixing bolt (9) reinforces the fit; the clamping nut (11) applies axial pressure to the pressure plate (10). This riveting fixture has the characteristics of wide applicability, stable clamping, accurate self-positioning, rapid assembly and disassembly, reduced labor intensity, and reduced production costs.

Description

Technical Field

[0001] This utility model belongs to the field of mechanical technology and relates to a multi-functional riveting fixture used for riveting and fixing transmission discs and transmission seats with rivets. Background Technology

[0002] Riveting is a common process in the machinery industry. Existing specialized riveting machines have different processing ranges. Due to differences in the design structure and transmission requirements of riveted products, the product dimensions vary. When the dimensions of a new product exceed the working range of the original riveting machine, it is necessary to purchase a larger-scale riveting machine. The cost of purchasing new equipment is too high. Furthermore, due to the structural limitations of specialized riveting machines, manual handling is required during riveting, increasing labor intensity and labor costs, and problems such as inability to quickly and accurately position the product may arise. Utility Model Content

[0003] The technical problem of this utility model is: The new equipment has issues with high costs and quality control during the riveting process.

[0004] The purpose of this utility model is: This utility model aims to provide a multifunctional riveting fixture capable of axial positioning, radial centering, and variable workpiece diameter. This riveting fixture features an ingenious structural design, strong specialization, specific adaptability, scientifically selected materials, a safe and reliable structure, long service life, and a wide range of applications. It boasts stable clamping, accurate self-positioning, rapid loading and unloading, and easy repositioning. It also has strong error-proofing and correction functions, accurately matching the positioning and clamping requirements of the workpiece, minimizing workpiece deformation. It is particularly suitable for standardized, mass-produced equipment parts, offering safe and reliable operation. The clamping and unloading process is simple and efficient, saving auxiliary time, improving operational efficiency, and exhibiting good repeatability, ensuring consistent processing of each batch of workpieces, reducing quality fluctuations, and minimizing over-reliance on operator skills.

[0005] The technical solution of this utility model is: This utility model proposes a cold-working riveting fixture with variable diameter and self-positioning function, comprising: an upper plate (1), a guide post (2), a punch seat (3), a fixing sleeve (4), a punch (5), a guide sleeve (6), a base plate (7), a mold base (8), a fixing bolt (9), a pressure plate (10), and a clamping nut (11), wherein: the upper plate (1) and the guide post (2) are interference-fitted; the upper plate (1) and the punch seat (3) are clearance-fitted; the fixing sleeve (4) is configured to load the punch (5) and transmit the equipment loading pressure to the punch (5); the upper plate (1) and the base plate (7) of the fixture are slidably fitted through the guide post (2) and the guide sleeve (6); the mold base (8) has multiple evenly distributed grooves, each groove having the same size, and is automatically centered when assembled with the base plate (7), and is reinforced by the fixing bolt (9); the clamping nut (11) is configured to apply axial pressure to the pressure plate (10).

[0006] The advantages and beneficial effects of this utility model are: This utility model relates to a cold-working riveting fixture: 1. This riveting fixture is simple and convenient to use, and the riveting quality is stable.

[0007] 2. This riveting jig has an ingenious structural design, a wide range of applications, multiple functions, and multiple uses. It is characterized by technological innovation and has unique features such as self-centering stability, accurate positioning, and the ability to replace dedicated riveting machines.

[0008] 3. This riveting fixture is fast, efficient, practical, and safe, with a wide range of applications and powerful error prevention and correction functions. It can significantly reduce processing preparation time and costs, improve processing efficiency, save processing time, and reduce processing and manufacturing costs, resulting in significant economic and social benefits. It provides strong technical equipment support for a substantial improvement in the core capabilities of tooling and mold manufacturing.

[0009] 4. This riveting fixture is the first and only one of its kind in the industry. Attached Figure Description

[0010] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments of this utility model will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0011] Figure 1 This is a schematic diagram of the overall structure of a cold working riveting fixture with variable diameter and self-positioning function; Figure 2 This is a top sectional view of a cold-working riveting jig with variable diameter and self-positioning functions.

[0012] Among them: upper plate (1), guide post (2), punch seat (3), fixed sleeve (4), punch (5), guide sleeve (6), bottom plate (7), mold base (8), fixing bolt (9), pressure plate (10), and clamping nut (11). Detailed Implementation

[0013] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this utility model.

[0014] It should be noted that, where there is no conflict, the embodiments of this utility model and the features therein can be combined with each other, and the various embodiments can be referenced and cited in turn. The present utility model will now be described in detail with reference to the accompanying drawings and embodiments.

[0015] This cold-working riveting jig includes: upper plate (1), guide post (2), punch seat (3), fixing sleeve (4), punch (5), guide sleeve (6), bottom plate (7), mold base (8), fixing bolt (9), pressure plate (10), and clamping nut (11).

[0016] Upper plate (1): This part is made of high-quality carbon structural steel 45# steel and is processed by flat grinding, machining center, heat treatment, coordinate grinding and other processes. The external dimensions are 450 mm long × 120 mm wide × 30 mm thick. At a point 73 mm to the right of the center line in the length direction, a stepped hole with a bottom hole diameter of φ40 mm and a countersunk hole diameter of φ85 mm and a depth of 20 mm is machined and fitted with the punch seat (3) with clearance. At a point 182 mm to the left and right of the center line in the length direction, through holes with a diameter of φ18 mm are machined and fitted with the guide post (2) with interference fit. Its main function is to load and fix the punch seat (3) and the guide post (2).

[0017] Guide post (2): This part is made of tool steel GCr15 steel and is processed by turning, heat treatment and external grinding. The outer diameter is φ20mm and the length is 200mm. One end is machined with a step with a diameter of φ18mm and a length of 28mm. The diameter of φ18mm is ground to fit with two φ18mm through holes on the upper plate (1) with an interference fit of 0.05-0.08mm. Its main function is to cooperate with the guide sleeve (6) to provide positioning and guidance.

[0018] Punch holder (3): This part is made of high-quality tool steel GCr15 and is processed by turning, heat treatment, internal grinding, external grinding and surface grinding. The shape is a stepped cylinder, with an outer diameter of φ83mm and a length of 20mm in the upper section, and an outer diameter of φ40mm and a length of 60mm in the lower section. The outer diameter is machined with M40×2 threads with a thread length of 45mm, and the inner hole is machined with a diameter of φ25mm and a depth of 45mm. Its main function is to load the punch (5) and transmit the equipment loading pressure to the punch (5).

[0019] Fixed sleeve (4): This part is made of high-quality tool steel GCr15 material and is processed by turning, heat treatment, internal grinding, external grinding and surface grinding. The part is 45mm long, with an outer diameter of φ60mm, an inner diameter of φ40mm and a length of 40mm, and is machined with an internal thread of M40×2 with a length of 30mm. Its main function is to fix the punch (5).

[0020] Punch (5): This part is made of mold steel LD material and is processed by turning, heat treatment, external grinding, hard turning, and grinding. The part is 115mm long, with an outer diameter of φ25mm and a length of 40mm, an outer diameter of φ38mm and a length of 5mm, and an outer diameter of φ28mm and a length of 70mm. The outer diameter φ28 end face is machined with an inner spherical concave surface of φ13.4mm deep, with a 70° chamfer at a depth of 2.16mm tangent to the inner spherical surface. The parallelism between the inner shape of the punch head and the upper end face is ≤0.01mm, ensuring that when the punch presses the rivet, the upper end face is subjected to uniform and stable force, and the rivet can be subjected to force evenly and uniformly, resulting in uniform deformation. Its main function is to make the rivet undergo fixed cold extrusion deformation by directly contacting the inner spherical concave surface with the rivet under the action of the equipment loading pressure.

[0021] Guide sleeve (6): This part is made of 45# steel and is processed by turning, heat treatment, internal grinding, external grinding and polishing. The part is 130mm long, with an outer diameter of φ40mm that is interference-fitted with the hole on the base plate (7), and an inner diameter of φ20mm that is clearance-fitted with the outer diameter of the guide post (2). The guide sleeve is machined with an oil groove and polished, and lubricated to ensure smooth movement of the guide post (2). Its main function is to cooperate with the guide post (2) to provide positioning and guidance.

[0022] Base plate (7): This part is made of high-quality carbon structural steel 45# steel and is processed by surface grinding, machining center, heat treatment, coordinate grinding and other processes. The external dimensions are 450 mm long × 300 mm wide × 30 mm thick. At 182 mm offset to the left and right of the center line in the length direction, through holes with a diameter of φ40 mm are machined to fit with the guide sleeve (6) with an interference fit of 0.05-0.08 mm. At 60 mm offset to the left and right of the center line in the length direction, stepped holes with a bottom diameter of φ12 mm and an opening diameter of φ20 mm and a depth of 20 mm are machined. Its main function is to load and fix the guide sleeve (6) and the mold base (8).

[0023] Mold base (8): This part is made of high-quality tool steel GCr15 material and is processed by turning, surface grinding, machining center, heat treatment, external grinding, and scraping with measuring clamp. The bottom outer diameter is φ180mm and the length is 50mm, the center outer diameter is φ40mm and the top is 65mm, the concave end face is 10mm, and the upper end is an M26×1.5 external thread with a length of 40mm. Its axial boss has a centering function to ensure the radial positioning of the workpiece; with the boss center line as the reference, the two ends of the mold base are ground with a parallelism of 0.01mm, a straightness of 0.01mm, and a flatness of 0.02mm; with the boss center line as the reference, the grooves are machined evenly and symmetrically with a position accuracy of 0.02mm. Its main function is to support and fix the workpiece connecting seat (100), connecting plate (200), and rivet (300).

[0024] Fixing bolt (9): Uses general-purpose M12 hex socket head cap bolts with a strength grade of 4.8, saving on self-manufacturing costs. Its main function is to fasten the mold base (8) and prevent workpiece vibration and displacement during the riveting process, which could cause dimensional deviations.

[0025] Pressure plate (10): Made of carbon structural steel 45#, processed by milling, heat treatment, and surface grinding. Outer diameter is φ60mm, inner diameter is φ28mm, and length is 10mm. Its main function is to apply axial pressure to the workpiece connecting seat (100), fix the workpiece connecting seat (100), and prevent workpiece vibration and displacement during the riveting process, which could cause dimensional deviations.

[0026] 11. Compression nut: A general-purpose M26×1.5 strength grade 4.8 nut is used to save on self-manufacturing costs. Its main function is to apply axial pressure to the pressure plate (10) to fix the connecting seat (100) of the workpiece.

[0027] This cold-working riveting fixture is manufactured through the following steps. The objects processed by this cold-working riveting fixture include: connecting seat (100), connecting plate (200), and rivet (300). Step 1: Prepare all the workpieces. Connect the guide post (2) of the jig to the upper plate (1) by interference fit, connect the punch seat (3) to the upper plate (1) by interference fit, install the punch (5) into the punch seat (3), and tighten it with the fixing sleeve (4).

[0028] Step 2: Use general-purpose T-bolts to fix the upper plate of the fixture to the press plate and pre-tighten it.

[0029] Step 3: Personnel adjust the position of the jig and tighten it according to their operating habits.

[0030] Step 4: The guide sleeve (6) is connected to the base plate (7) by an interference fit. The mold base (8) is connected to the base plate (7) and fixed with fixing bolts (9). The clamping nut (11) is screwed onto the mold base (8). Lubricating oil is sprayed inside the guide sleeve (6).

[0031] Step 5: Adjust the height of the hydraulic press plate and insert the guide post (2) into the guide sleeve (6).

[0032] Step 6: As shown in the drawing, install the rivet, part 2, and part 1 into the fixture in sequence. The axis of the part is collinear with the axis of the mold base (8), and the lower plane of part 2 is flush with the upper surface of the mold base (8). Insert the pressure plate (10), tighten the clamping nut (11) to fix the workpiece and prevent the workpiece from moving during the processing.

[0033] Step 7: After riveting is completed, check the retaining sleeve (4) to ensure it is not loose. Loosen the clamping nut (11), rotate the part, and complete the riveting process in sequence.

[0034] Step 8: Replace with a new part and repeat steps 6-7 for the next processing.

[0035] In some embodiments, the fixture is fixed on the machine tool workbench according to the usage position to ensure that the fixture upper plate (1) is stable and safe to use. The fixture upper plate (1) and the base plate (7) are slidably engaged through the guide post (2) and the guide sleeve (6) to ensure accurate positioning. The mold base (8) has multiple evenly distributed grooves, which can fix the rivets in the grooves. When clamping, the center of the workpiece can be positioned. By rotating the workpiece, multiple rivets can be pressed and fixed.

[0036] The groove size of the mold base (8) is manufactured in different specifications according to product requirements. The positioning dimensions are consistent. It is automatically centered when assembled with the base plate (7) and reinforced by fixing bolts (9), thereby ensuring the installation dimension accuracy and greatly saving the manufacturing cost and time cost of the mold.

[0037] The inner shape of the punch (5) and the parallelism between the upper end face are ≤0.01mm, ensuring that when the punch presses the rivet, the upper end face is subjected to uniform and stable force, and the rivet can be subjected to force in a comprehensive and uniform manner, and the deformation is uniform.

[0038] Pressure calculation for press-fit rivets: Basic parameters determined: The rivet material is Q235 steel, with a diameter of 8mm, and the material yield strength (σ) is... S The strength is 235 MPa, and the cross-sectional area of ​​the rivet rod is A = πd. 2 / 4 (unit: mm) 2The safety factor (K = 1.2 to 1.5) is used because the rivet head needs to be deformed (flat-head rivets are pressed into round heads). In addition to considering material inhomogeneity and tooling error factors, the force of head deformation needs to be considered, and the safety factor (K = 1.5 to 2.0) should be appropriately increased. K is taken as 1.6.

[0039] Riveting force calculation: F=K×σ S ×πd 2 / 4 = 1.6 × 235 × π × 8 2 / 4≈18890N (18.89KN) The rated pressure of the press needs to be greater than the calculated value, usually with a margin of 20% to 30%. Therefore, a press with a capacity of 3 tons or more can meet the tooling requirements.

[0040] Calculation of plastic deformation: The process of pressing a flat-head rivet into a round head is a cold plastic deformation. Pressure is applied through a mold, forcing the rivet head material to flow from a flat shape to a spherical / round head shape, and the deformation follows the law of conservation of volume.

[0041] Basic parameters: rivet flat head diameter D0 is 8mm, flat head height h0 (original exposed head height) is 10mm, target round head diameter D1, round head height h1.

[0042] Volume conservation calculation V 原始 =V 变形后 ,Right now: V 原始 =πD0 2 / 4×h0=π×8 2 / 4×10≈502.4mm 3 After deformation, the round head approximates a spherical segment, with a volume of: V 变形后 =πh1 2 (3R-h1) / 3 Where R is the diameter of the spherical head (if the diameter of the spherical head is D1, then R≈D1 / 2), simplified calculation (when the spherical head is a standard circle, h1≈D1 / 2): V 变形后 =πD1 3 / 12 By V 原始 =V 变形后 Solving for D1, we get D1 = 12.42 mm.

[0043] D1=1.55D 0， The rivet shank has sufficient radial expansion, reasonable axial compression, and the riveting force meets the requirements.

[0044] It should be noted that the above process operations can be combined to varying degrees. For the sake of brevity, the implementation methods of various combinations will not be elaborated here. Those skilled in the art can flexibly adjust the order of the above operation steps or flexibly combine the above steps according to actual needs.

[0045] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of this utility model, but the protection scope of this utility model is not limited thereto. Any person skilled in the art can easily conceive of various equivalent modifications or substitutions within the technical scope disclosed in this utility model, and these modifications or substitutions should be covered within the protection scope of this utility model.

Claims

1. A cold-working riveting fixture with variable diameter and self-positioning function, characterized in that, include: The components are: upper plate (1), guide post (2), punch seat (3), fixing sleeve (4), punch (5), guide sleeve (6), bottom plate (7), mold base (8), fixing bolt (9), pressure plate (10), and clamping nut (11), wherein: the upper plate (1) and guide post (2) are interference-fitted; the upper plate (1) and punch seat (3) are clearance-fitted; the fixing sleeve (4) is configured to load the punch (5) and transmit the equipment loading pressure to the punch (5); the upper plate (1) and bottom plate (7) of the mold are slidably fitted through the guide post (2) and guide sleeve (6); the mold base (8) has multiple evenly distributed grooves, each groove having the same size, and is automatically centered when assembled with the bottom plate (7), and is reinforced by the fixing bolt (9); the clamping nut (11) is configured to apply axial pressure to the pressure plate (10).

2. The cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The upper plate (1) is made of high-quality carbon structural steel 45# steel, with an external dimension of 450mm long × 120mm wide × 30mm thick. At a point 73mm to the right of the center line in the length direction, a stepped hole with a bottom hole diameter of φ40mm and a countersunk hole diameter of φ85mm and a depth of 20mm is machined and fitted with the punch seat (3) with clearance. At a point 182mm to the left and right of the center line in the length direction, through holes with a diameter of φ18mm are machined and fitted with the guide post (2) with interference fit.

3. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The guide post (2) is made of tool steel GCr15 steel with an outer diameter of φ20mm and a length of 200mm. One end is machined with a step with a diameter of φ18mm and a length of 28mm. The diameter of φ18mm is ground to fit the two φ18mm through holes on the upper plate (1) with an interference of 0.05-0.08mm.

4. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The punch seat (3) is made of high-quality tool steel GCr15 material. It is a stepped cylinder with an outer diameter of φ83mm and a length of 20mm in the upper section and an outer diameter of φ40mm and a length of 60mm in the lower section. The outer diameter is machined with M40×2 threads with a thread length of 45mm. The inner hole is machined with a diameter of φ25mm and a depth of 45mm.

5. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The fixing sleeve (4) is made of high-quality tool steel GCr15 material. The part is 45mm long, with an outer diameter of φ60mm, an inner diameter of φ40mm and a length of 40mm. The internal thread is M40×2 and 30mm long.

6. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The punch (5) is made of mold steel LD material. The part is 115mm long, with an outer diameter of φ25mm and a length of 40mm, an outer diameter of φ38mm and a length of 5mm, and an outer diameter of φ28mm and a length of 70mm. The outer diameter φ28 end face is machined with an inner spherical concave surface of φ13.4mm deep and 5mm deep. A 70° chamfer is machined at a depth of 2.16mm and tangent to the inner spherical surface. The parallelism between the inner shape of the punch head and the upper end face is ≤0.01mm, ensuring that when the punch presses the rivet, the upper end face is subjected to uniform and stable force, and the rivet can be subjected to force in a comprehensive and uniform manner, with uniform deformation.

7. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The guide sleeve (6) is made of 45# steel. The part is 130mm long and has an outer diameter of φ40mm that is interference fit with the hole on the base plate (7). The inner diameter of φ20mm is clearance fit with the outer diameter of the guide post (2). The guide sleeve is machined with an oil groove and polished. Lubricating oil is applied to ensure that the guide post (2) moves smoothly.

8. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The base plate (7) is made of high-quality carbon structural steel 45# steel, with an external dimension of 450mm long × 300mm wide × 30mm thick. At 182mm offset to the left and right of the center line in the length direction, a through hole with a diameter of φ40mm is machined and is interference-fitted with the guide sleeve (6) with an interference of 0.05-0.08mm. At 60mm offset to the left and right of the center line in the length direction, a stepped hole with a bottom hole of φ12mm and an opening diameter of φ20mm and a depth of 20mm is machined.

9. A cold-working riveting fixture with variable diameter and self-positioning function according to claim 1, characterized in that, in: The mold base (8) is made of high-quality tool steel GCr15 material. The bottom outer diameter is φ180mm and the length is 50mm. The center outer diameter is φ40mm and the top is 65mm. The recessed end face is 10mm. The upper end is an M26×1.5 external thread with a length of 40mm. Its axial boss has a centering function to ensure the radial positioning of the workpiece. Based on the center line of the boss, the two ends of the mold base are ground with a parallelism of 0.01mm, a straightness of 0.01mm, and a flatness of 0.02mm. Based on the center line of the boss, the groove is machined evenly and symmetrically with a position accuracy of 0.02mm.

10. A cold-working riveting fixture with variable diameter and self-positioning function according to any one of claims 1-9, characterized in that, in: The pressure plate (10) is made of carbon structural steel 45# steel, with an outer diameter of φ60mm, an inner diameter of φ28mm, and a length of 10mm. Its main function is to apply axial pressure to the processing object connecting seat (100), fix the processing object connecting seat (100), and prevent the workpiece from vibrating or shifting during the riveting process, which would cause dimensional deviations.

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