Wire drawing test fixture and method

Abstract

The present disclosure provides a wire drawing test tool and method, which is applied to a tensile testing machine. The test tool comprises a barrel having an accommodating space inside, a communication hole on the barrel in communication with the accommodating space, the communication hole being used for allowing a workpiece to be tested to enter, a fixing part arranged at one end of the barrel and used for connecting with a first clamp of the tensile testing machine, and an assembly part arranged at the other end of the barrel away from the fixing part and used for mounting a drawing die. A drawing through hole is formed along the axial direction of the assembly part, and the drawing through hole is used for allowing the workpiece to be tested to pass out and connect with a second clamp of the tensile testing machine. The wire drawing test tool provided by the present disclosure can simulate the real cold drawing process in the laboratory environment by assembling the barrel and the assembly part, mounting the drawing die in the assembly part, allowing the workpiece to be tested to pass through the reduced hole of the drawing die, and connecting with the tensile testing machine fixedly from the drawing through hole, so as to obtain effective experimental data for guiding production.

Description

Technical Field

[0001] This application relates to the field of cold drawing technology, and in particular to a wire drawing test fixture and method. Background Technology

[0002] In the cold drawing process of steel bars, equipment such as winches are usually used to force the steel bars through a mold with a hole diameter slightly smaller than the diameter of the steel bars in order to improve the strength and dimensional accuracy of the steel bars.

[0003] Operators can only rely on experience to control and adjust the die aperture and drawing speed, and cannot know the corresponding relationship between the stress and strain of the material and the speed. Although a laboratory drawing test machine can be used to simulate cold drawing.

[0004] However, traditional testing methods involve directly clamping the reinforcing bars in the testing machine fixtures for tensile testing. The stress state of these methods is significantly different from the actual pull-out stress mode (coexistence of axial tension and radial mold wall constraint), resulting in test data that cannot effectively guide production. Summary of the Invention

[0005] This application provides a wire pull-out test fixture and method.

[0006] In a first aspect, this application proposes a wire drawing test fixture for use in a tensile testing machine, comprising: The cylindrical body has an internal receiving space, and the cylindrical body is provided with a connecting hole that communicates with the receiving space. The connecting hole is used to allow the workpiece to be tested to enter. A fastener, located at one end of the cylinder, is used to connect with the first clamp of the tensile testing machine; The fitting is located at the other end of the cylinder away from the fixed part, and the fitting is used to install the wire drawing die; A pull-out through hole is provided along the axial direction of the assembly. The pull-out through hole is used for the workpiece to pass through and connect with the second fixture of the tensile testing machine.

[0007] In some embodiments, the assembly is provided with a groove, the opening of the groove facing the inside of the cylinder, a pull-out through hole is formed at the bottom of the groove, and one end of the pull-out through hole communicates with the groove, while the other end of the pull-out through hole communicates with the outside of the cylinder. The wire drawing die is assembled in the groove. The wire drawing die is provided with a shrinkage limiting hole along the axial direction. The shrinkage limiting hole is set on the same axis as the drawing through hole. The diameter of the drawing through hole and the diameter of the workpiece are both larger than the diameter of the shrinkage limiting hole. The shrinkage limiting hole is used to reduce the cross-section of the workpiece.

[0008] In some embodiments, the assembly is detachably connected to the cylinder, and multiple wire drawing dies are provided. The size of the limiting holes of the multiple wire drawing dies is different, and one of the multiple wire drawing dies is selected and installed in the groove.

[0009] In some embodiments, the outer periphery of the fitting is provided with external threads, and the inner wall of the other end of the cylinder is provided with internal threads, so that the fitting can be screwed into the cylinder.

[0010] In some embodiments, the radial cross-sectional shape of the pull-through hole is hexagonal.

[0011] In some embodiments, a receiving member is included, which is disposed within the cylinder and located between the communicating hole and the fitting, for holding a lubricating medium; The receiving component has a receiving hole along the axial direction of the cylinder, which is used to allow the lubricating medium and the workpiece to be tested to pass through.

[0012] In some embodiments, the diameter of the receiving hole tends to decrease from the connecting hole to the fitting.

[0013] In some embodiments, the outer side wall of the receiver is provided with at least two mounting holes, which are spaced apart and arranged opposite to each other; The outer wall of the cylinder is provided with a limiting hole corresponding to the mounting hole, and the limiting hole penetrates the outer wall of the cylinder. A limiting pin is inserted into the mounting hole through the limiting hole to realize the limiting installation of the receiving part.

[0014] In some embodiments, the connecting hole is a strip hole, and multiple strip holes are spaced apart along the circumference of the cylinder, and the strip holes extend along the length of the cylinder.

[0015] Secondly, this application proposes a wire pull-out test method based on the wire pull-out test fixture proposed in the first aspect; Install wire pull-out test fixtures; Lubricating material is inserted into the container through the connecting hole; Securely connect the fixture to the upper clamp of the tensile testing machine, and adjust the upper clamp to an appropriate height; One end of the workpiece to be tested is pre-pressed into a point, which is then passed through the connecting hole into the cylinder and out through the pull-out through hole of the assembly, and connected to the lower clamp of the tensile testing machine. Start the pull-out testing machine.

[0016] Compared to existing technologies, the wire drawing test fixture proposed in this disclosure, through the assembly of a cylinder and an assembly, and the installation of a drawing die in the assembly, allows the workpiece to be tested to enter through the connecting hole of the cylinder, pass through the constriction hole of the drawing die, and exit through the drawing through hole of the assembly, and be fixedly connected to the drawing test machine. This enables the simulation of the combined stress state of axial tension and radial die wall constraint on the workpiece in the real cold drawing process in a laboratory environment, thereby obtaining effective experimental data for guiding production. Attached Figure Description

[0017] Figure 1This is a schematic diagram of the wire drawing test fixture structure disclosed in this application; Figure 2 This is a schematic diagram of the assembly of the wire drawing test fixture and the wire drawing die disclosed in this application; Figure 3 This is a schematic diagram of the cylindrical structure from a first-view perspective as disclosed in this application; Figure 4 This is a schematic diagram of the cylindrical structure from a second perspective as disclosed in this application; Figure 5 This is an assembly diagram of the wire drawing die and assembly parts disclosed in this application; Figure 6 This is a structural schematic diagram of the assembly disclosed in this application; Figure 7 This is a top-view structural schematic diagram of the assembly disclosed in this application; Figure 8 This is a schematic diagram of the structure of the receiving component disclosed in this application.

[0018] Figure label: 10. Cylinder body; 11. Connecting hole; 20. Fastener; 30. Assembly; 31. Pull-out through hole; 32. Groove; 40. Wire drawing die; 41. Shrinkage hole; 50. Receiving component; 51. Receiving hole. Detailed Implementation

[0019] To better understand the technical solutions provided in the embodiments of this specification, the technical solutions of the embodiments of this specification will be described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the embodiments of this specification and the specific features in the embodiments are detailed descriptions of the technical solutions of the embodiments of this specification, rather than limitations on the technical solutions of this specification. In the absence of conflict, the embodiments of this specification and the technical features in the embodiments can be combined with each other.

[0020] In this document, relational terms such as "first" and "second" are used merely to distinguish one entity or operation from another, without necessarily requiring or implying any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover 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 limitation, 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. The term "two or more" includes two or more cases.

[0021] Firstly, such as Figures 1-8 As shown, in a first aspect, this application proposes a wire drawing test fixture for use in a tensile testing machine, comprising: The cylindrical body 10 has an internal receiving space, and the cylindrical body 10 is provided with a connecting hole 11 that communicates with the receiving space. The connecting hole 11 is used to allow the workpiece to be tested to enter. The fastener 20 is located at one end of the cylinder 10 and is used to connect with the first clamp of the tensile testing machine. The fitting 30 is located at the other end of the cylinder 10 away from the fixed part, and the fitting 30 is used to install the wire drawing die 40. A pull-out through hole 31 is provided along the axial direction of the assembly 30. The pull-out through hole 31 is used for the workpiece to pass through and connect with the second fixture of the tensile testing machine.

[0022] Understandably, the wire drawing test fixture disclosed herein needs to be installed on a tensile testing machine. The structure of the test fixture includes a cylinder 10, which has a connecting hole 11 for the workpiece to be tested to enter the cylinder 10 through the connecting hole 11. A fixing member 20 is set at one end of the cylinder 10, and an assembly 30 is set at the other end of the cylinder 10 away from the fixing member 20. The assembly 30 is used to install the wire drawing die 40, and the assembly 30 has a drawing through hole 31 for the workpiece to pass through.

[0023] The wire drawing die 40 is used to reproduce the plastic deformation process in actual wire drawing production, in which the metal wire passes through the die hole to achieve a reduction in cross-section and an increase in length. When the second clamp of the tensile testing machine pulls the workpiece, such as the wire, through the wire drawing die 40, the inner hole contour of the wire drawing die 40 applies radial constraint and friction force to the wire. The wire drawing die 40 can be a set of components, which includes multiple wire drawing dies 40. The wire drawing dies 40 have the same outer diameter and can be adapted to the assembly 30 for installation. The inner diameter of the die hole of different wire drawing dies 40 is different. Different wire drawing dies 40 can be installed in the assembly 30 based on test requirements.

[0024] The wire drawing die 40 and the assembly 30 can be installed by interference fit, thread locking, etc., to prevent the die from moving or vibrating during the drawing process, which would affect the test accuracy. During installation, it is necessary to ensure that the axis of the drawing through hole 31 is consistent with the axis of the die hole of the wire drawing die 40, the axis of the cylinder, and the tensile direction of the tensile testing machine. The wire drawing die 40 is a workpiece that can be purchased on the market, so it will not be described in detail.

[0025] The cylindrical body 10 serves as the main frame of the tooling, and its internal space is used to accommodate the workpiece. The connecting hole 11 is opened on the top or side wall of the cylindrical body 10 as the workpiece inlet, and the diameter of the connecting hole 11 is larger than the original diameter of the workpiece.

[0026] The fastener 20 is used for the transmission and connection of tensile force between the wire drawing test fixture and the drawing test machine. It can be integrally formed with the cylinder 10. The fastener 20 can be plate-shaped, rod-shaped, etc., and the specific shape is not limited. It just needs to be able to be firmly connected to the first clamp or upper clamp of the drawing test machine. The axis of the fastener 20 is collinear with the axis of the cylinder 10 to ensure centering so that the drawing force can always be transmitted axially and avoid the generation of bending moment, etc.

[0027] The assembly 30 is an independent, detachable module that can be fixed to the other end of the cylinder 10 via threaded or flanged connections. The assembly 30 is made of a high-hardness, high-wear-resistant material to withstand pressure and friction, and to ensure the stability of the test.

[0028] The wire drawing test fixture proposed in this disclosure is assembled with a cylinder and an assembly 30, and a drawing die 40 is installed in the assembly 30. The workpiece to be tested enters from the connecting hole of the cylinder, passes through the constriction hole 41 of the drawing die 40, and exits from the drawing through hole 31 of the assembly 30, and is fixedly connected to the drawing test machine. This allows the fixture to simulate the combined stress state of axial tension and radial die wall constraint on the workpiece in the real cold drawing process in a laboratory environment, thereby obtaining effective experimental data for guiding production.

[0029] In some embodiments, the assembly 30 is provided with a groove 32, the opening of the groove 32 faces the inside of the cylinder, a pull-out through hole 31 is formed at the bottom of the groove 32, and one end of the pull-out through hole 31 communicates with the groove 32, while the other end of the pull-out through hole 31 communicates with the outside of the cylinder. The wire drawing die 40 is assembled in the groove 32. The wire drawing die 40 is provided with a shrinkage hole 41 along the axial direction. The shrinkage hole 41 is coaxially arranged with the drawing through hole 31. The diameter of the drawing through hole 31 and the diameter of the workpiece are both larger than the diameter of the shrinkage hole 41. The shrinkage hole 41 is used to reduce the cross section of the workpiece.

[0030] Understandably, the assembly 30 serves as an installation base and positioning mechanism, and is fixed to the other end of the cylinder 10 by means of threads, flanges, or lock nuts, thus becoming part of the structure of the cylinder 10.

[0031] The groove 32 is used to accommodate and limit the wire drawing die 40. The groove 32 can be a circular groove or a square groove. The shape of the groove 32 is adapted to the shape of the wire drawing die 40 to achieve the effect of limiting and supporting the wire drawing die 40.

[0032] Furthermore, the groove 32 is centrally located on the assembly 30 along the axis to ensure that the center line of the wire drawing die 40 assembled in the groove 32 coincides with the axis of the wire drawing test fixture, thereby satisfying the alignment requirement.

[0033] During the drawing process, the wire drawing die 40 is subjected to radial pressure and axial reaction force. At this time, the sidewall and bottom of the groove 32 provide support for the die to prevent the wire drawing die 40 from breaking or shifting.

[0034] The wire drawing die 40 is detachably connected to the assembly 30. The compression hole 41 extends from the connecting hole 11 to the drawing through hole 31 at the bottom of the groove, and includes the inlet area, compression area and sizing area in sequence. The wire drawing die 40 is a mature industrial workpiece used to deform wires, and will not be described in detail here.

[0035] The shrinkage orifice 41 is used to reduce the cross-section of wire (e.g., steel bar), elongate the grains, and improve the overall strength. The diameter of the shrinkage orifice 41 is smaller than the original diameter of the workpiece. When the workpiece passes through this area under tensile force, its cross-sectional area is forcibly reduced. During this process, the workpiece under test is simultaneously subjected to the tensile force applied by the tensile testing machine, the radial extrusion force applied by the shrinkage orifice 41, the shear stress generated by the internal flow of the material, and the huge sliding friction between the workpiece and the inner wall of the shrinkage orifice 41.

[0036] In some embodiments, the fitting 30 is detachably connected to the cylinder 10, and the wire drawing die 40 is provided with multiple dies. The size of the limiting hole 41 of the multiple wire drawing dies 40 is different, and one of the multiple wire drawing dies 40 is selected and installed in the groove 32.

[0037] Understandably, the assembly 30 is detachably connected to the cylinder 10 via threads or flanges, making it convenient to replace wire drawing dies 40 of different specifications.

[0038] To meet the requirements of drawing tests for wires of different diameters, a set of drawing dies 40 with different sizes of shrinkage holes 41 can be prepared.

[0039] In some embodiments, the outer periphery of the fitting 30 is provided with an external thread, and the inner wall of the other end of the cylinder 10 is provided with an internal thread, so that the fitting 30 and the cylinder 10 are screwed together.

[0040] In some embodiments, the radial cross-sectional shape of the pull-through hole 31 is hexagonal.

[0041] Understandably, the outer wall of the fitting 30 is machined with external threads, and the inner thread that matches it is machined inside the second end of the cylinder 10. By rotating the fitting 30, it is screwed into the cylinder 10 to achieve a fast connection.

[0042] The threaded connection generates a large preload, ensuring that the assembly 30 will not loosen or fall off during the pull-out process, and also prevents lubricant from leaking from the connection. The pull-out through hole 31 with a radial cross-section of hexagon allows the operator to easily tighten or loosen the assembly 30 by inserting a standard Allen wrench into the hexagonal hole.

[0043] In some embodiments, a receiving member 50 is included, which is disposed inside the cylinder 10 and located between the communicating hole 11 and the mounting part 30, for holding a lubricating medium. The receiving member 50 has a receiving hole 51 along the axial direction of the cylinder 10, which is used to allow the lubricating medium and the workpiece to be tested to pass through.

[0044] In some embodiments, the diameter of the receiving hole 51 tends to decrease from the connecting hole 11 to the fitting 30.

[0045] Understandably, the receiving element 50 is set inside the cylinder 10 and is assembled into a container for holding the lubricating medium. It has a receiving hole 51 along the axial direction, allowing the lubricating medium and the workpiece to be tested to pass through simultaneously, so that the workpiece can be fully and evenly coated with lubricant before entering the drawing die, thereby simulating real friction conditions.

[0046] The receiving hole 51 tends to narrow in the direction from the connecting hole 11 to the assembly 30, thus forming a tapered or flared channel. When the workpiece passes through the tapered receiving hole 51, the lubricant can be better gathered and guided to the workpiece surface that is about to enter the drawing die.

[0047] The side wall of the receiving component 50 is provided with at least two assembly holes, which are arranged opposite to each other; the side wall of the cylinder 10 is provided with at least two mounting through holes, and the mounting through holes and the assembly holes are arranged in a one-to-one correspondence. The fastener 20 passes through the mounting through holes and is inserted into the assembly holes to fix the receiving component 50.

[0048] In some embodiments, the outer side wall of the receiving member 50 is provided with at least two mounting holes, which are spaced apart and arranged opposite to each other; The outer wall of the cylinder is provided with a limiting hole corresponding to the mounting hole, and the limiting hole penetrates the outer wall of the cylinder. A limiting pin is inserted into the mounting hole through the limiting hole to achieve the limiting installation of the receiving part 50.

[0049] In some embodiments, the connecting hole 11 is a strip hole, and a plurality of strip holes are arranged at intervals along the circumference of the cylinder 10, and the strip holes extend along the length direction of the cylinder 10.

[0050] Understandably, multiple elongated slots extending along the axis of the cylinder 10 are formed circumferentially on the side wall of the cylinder 10. These slots serve as channels for adding lubricating medium into the receiving component 50. Simultaneously, the slots can also function as observation holes to monitor the progress of the workpiece drawing within the cylinder, check the condition of the lubricating medium, and detect any metal debris accumulation. Furthermore, the slots can act as venting channels, allowing air to escape from the cylinder during the workpiece drawing process.

[0051] Secondly, this application proposes a wire pull-out test method based on the wire pull-out test fixture proposed in the first aspect; Install wire pull-out test fixtures; Lubricating material is inserted into the receiving part 50 through the connecting hole 11; The fixing part 20 of the test fixture is fixedly connected to the upper clamp of the tensile testing machine, and the upper clamp is adjusted to an appropriate height; One end of the workpiece to be tested is pre-pressed into a point, and the point is used to pass through the connecting hole 11 into the cylinder 10 and out through the pull-out through hole 31 of the assembly 30 and connect to the lower clamp of the tensile testing machine. Start the pull-out testing machine.

[0052] Understandably, a receiving component 50 is installed inside the cylinder 10, and a specific drawing die with a specific aperture is selected and assembled onto the assembly 30 to form the assembly 30.

[0053] Lubricating medium, which is grease, is added into the receiving part 50 through the connecting hole 11. The lubricating medium can simulate the real drawing production process and ensure that effective drawing data is obtained.

[0054] The upper clamp of the tensile testing machine is securely connected by fixing the cylinder 10, and the upper clamp is adjusted to a suitable height.

[0055] Then, one end of the workpiece to be tested is pre-pressed into a pointed tip, which passes sequentially through the connecting hole 11, the receiving part 50, and the mounting part 30 before extending out from the cylinder 10. The pointed tip can smoothly pass through the pull-out through hole 31 of the mounting part 30 and be clamped and connected to the lower clamp of the pull-out testing machine. The diameter of the pointed tip can be slightly smaller than the diameter of the pull-out through hole 31, so that the end of the workpiece can smoothly pass through and be connected to the lower clamp.

[0056] Finally, the pull-out testing machine is started, and the lower clamp moves downward at a set speed to pull the workpiece and collect data. The pull-out testing machine will record and output the force-displacement curve in real time, thereby obtaining all information such as material deformation resistance, die friction, and lubrication effect from the curve, which can be used to guide production and optimize the process.

[0057] The above embodiments are only used to illustrate the technical solutions of this application, and are not intended to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this application.

[0058] Although preferred embodiments have been described in this specification, those skilled in the art, upon learning the basic inventive concept, can make other changes and modifications to these embodiments. Therefore, the appended claims are intended to be interpreted as including the preferred embodiments as well as all changes and modifications falling within the scope of this specification.

[0059] Obviously, those skilled in the art can make various modifications and variations to this specification without departing from its spirit and scope. Therefore, if such modifications and variations fall within the scope of the claims and their equivalents, this specification is also intended to include such modifications and variations.

Claims

1. A wire drawing test fixture, applied to a tensile testing machine, characterized in that, include: A cylindrical body with an internal receiving space, and a communicating hole on the cylindrical body that communicates with the receiving space, the communicating hole being used to allow the workpiece to be tested to enter; A fastener is provided at one end of the cylinder and is used to connect to the first clamp of the tensile testing machine; An assembly is located at the other end of the cylinder away from the fixed part, and the assembly is used to install the wire drawing die; A pull-out through hole is provided along the axial direction of the assembly, which is used for the workpiece to pass through and connect with the second fixture of the tensile testing machine.

2. The wire drawing test fixture according to claim 1, characterized in that, The assembly is provided with a groove, the opening of the groove facing the inside of the cylinder, the pull-out through hole is formed at the bottom of the groove, one end of the pull-out through hole is connected to the groove, and the other end of the pull-out through hole is connected to the outside of the cylinder. The wire drawing die is assembled in the groove. The wire drawing die is provided with a shrinkage limiting hole along the axial direction. The shrinkage limiting hole is coaxial with the drawing through hole. The diameter of the drawing through hole and the diameter of the workpiece are both larger than the diameter of the shrinkage limiting hole. The shrinkage limiting hole is used to reduce the cross-section of the workpiece.

3. The wire drawing test fixture according to claim 2, characterized in that, The assembly is detachably connected to the cylinder body. The drawing die is provided in multiple sizes, and the limiting holes of the multiple drawing dies are different. One of the multiple drawing dies is selected and installed in the groove.

4. The wire drawing test fixture according to claim 3, characterized in that, The outer periphery of the fitting is provided with external threads, and the inner wall of the other end of the cylinder is provided with internal threads, so that the fitting can be screwed into the cylinder.

5. The wire drawing test fixture according to claim 3, characterized in that, The radial cross-sectional shape of the drawing through hole is hexagonal.

6. The wire drawing test fixture according to any one of claims 1-5, characterized in that, include: A receiving element is disposed inside the cylinder and located between the communicating hole and the assembly, for holding a lubricating medium; The receiving component has a receiving hole along the axial direction of the cylinder, and the receiving hole is used to allow the lubricating medium and the workpiece to pass through.

7. The wire drawing test fixture according to claim 6, characterized in that, The diameter of the receiving hole tends to decrease from the connecting hole to the assembly.

8. The wire drawing test fixture according to claim 6, characterized in that, The outer side wall of the receiving member is provided with at least two mounting holes, which are spaced apart and arranged opposite to each other; The outer side wall of the cylinder is provided with a limiting hole corresponding to the mounting hole, and the limiting hole penetrates the outer side wall of the cylinder. A limiting pin is inserted into the mounting hole through the limiting hole to realize the limiting installation of the receiving component.

9. The wire drawing test fixture according to claim 1, characterized in that, The connecting hole is a strip-shaped hole, and multiple strip-shaped holes are spaced apart along the circumference of the cylinder, and the strip-shaped holes extend along the length of the cylinder.

10. A method for wire pull-out testing, characterized in that, Based on the wire drawing test fixture according to any one of claims 1-9; Install the wire pull-out test fixture; Lubricating material is inserted into the container through the connecting hole; Securely connect the fixture to the upper clamp of the tensile testing machine, and adjust the upper clamp to an appropriate height; One end of the workpiece to be tested is pre-pressed into a pointed tip, which is then passed through the connecting hole into the cylinder and exits through the pull-out through hole of the assembly, and is connected to the lower clamp of the tensile testing machine. Start the pull-out testing machine.

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