Stretching device and control method thereof

Abstract

The invention discloses a stretching device and a control method thereof.The stretching device comprises a mounting base and two sliding tables arranged oppositely, the sliding tables are arranged on the mounting base in a sliding mode, the two sliding tables are each provided with a stretching clamp used for stretching a sample strip, and the stretching device is characterized in that the two sliding tables are each connected with a driving mechanism; the driving mechanism can drive the sliding table to slide, and the sliding table slides to drive the stretching clamp to stretch the sample strip bidirectionally. According to the two-way stretching device, the two driving mechanisms are started to drive the sliding table to move, the sliding table moves to drive the stretching clamp to move, the stretching clamp conducts two-way stretching on a spline, deformation of the spline is more uniform, and the two-way stretching device has the wide stretching rate range and multiple movement modes.

Description

Technical Field

[0001] The invention relates to a technology for studying the structural evolution of a polymer film during dynamic stretching at different temperatures using synchrotron radiation X-ray scattering, and belongs to the technical field of polymer material testing, in particular to a stretching device and a control method thereof. Background Art

[0002] During their service, semi-crystalline polymer materials are inevitably affected by external forces and temperature, causing deformation or even fracture. The plastic deformation process of semi-crystalline polymers is very complex, mainly including stress-induced chip slip, lamellar fragmentation and chain disentanglement. At present, due to the limitations of the intensity of domestic synchrotron radiation light sources and in-situ stretching equipment, scientific researchers can only study the structural evolution of polymers under quasi-static conditions at low speeds, small strains or after stress relaxation. Thanks to the rapid development of domestic high-spatial-resolution and time-resolved synchrotron X-ray scattering technology, the structural evolution of semi-crystalline polymers during deformation can be observed in situ.

[0003] The current commercially available stretching devices can only perform uniform motion and have a narrow stretching speed range, which cannot meet the scientific research needs of polymer materials in high-speed deformation and cyclic dynamic stretching experiments. At the same time, the current contact heating scheme cannot fully heat the entire specimen.

[0004] In view of this, the present invention is proposed. Summary of the invention

[0005] The object of the present invention is to provide a stretching device and a control method thereof, so as to achieve a wide stretching rate range, multiple stretching modes, and uniform heating and deformation of the spline of the stretching device.

[0006] In order to solve the above technical problems, the basic concept of the technical solution adopted by the present invention is:

[0007] A stretching device comprises: a mounting base and two slides arranged opposite to each other, the slides being slidably arranged on the mounting base, the two slides respectively having a stretching clamp for stretching a spline, the two slides being respectively connected to a driving mechanism, the driving mechanism being able to drive the slides to slide, and the sliding of the slides driving the stretching clamp to bidirectionally stretch the spline.

[0008] Furthermore, the power output shaft of the driving mechanism is connected to the slide table through a ball screw, and the ball screw converts the rotary motion of the power output shaft into linear motion, which is used to drive the slide table to slide.

[0009] Furthermore, the stretching device also includes:

[0010] A spline housing having a cavity therein for accommodating the spline;

[0011] a heating unit having a gas channel connected to the spline housing and a heating structure for heating the gas in the gas channel;

[0012] a blast unit, connected to the gas passage, and used for introducing gas into the gas passage;

[0013] The gas outputted by the blowing unit enters the gas channel, is heated by the heating structure, and then is inputted into the cavity of the spline housing to heat the spline.

[0014] Furthermore, the heating unit comprises a heat-conducting block, on which a hole penetrating the heat-conducting block is provided, and the hole forms the gas channel;

[0015] The heat conducting block is a columnar structure, and the gas channel extends from one end of the columnar structure to the other end and passes through both ends of the columnar structure;

[0016] Preferably, a spiral heat-conducting wire is provided in the gas channel.

[0017] Furthermore, the heat conducting block also has a mounting portion, and the heating structure is arranged on the mounting portion;

[0018] Preferably, the heat conductive block comprises first and second blocks divided from one end to the other end, and the dividing surfaces of the first and second blocks respectively have groove structures, which are buckled to form the mounting portion, and the heating structure is inserted into the mounting portion.

[0019] Furthermore, it also includes a temperature measuring unit, which is arranged between the heating unit and the spline housing and is used to detect the temperature of the blown hot air;

[0020] Preferably, a mounting opening is provided on the top wall of the spline housing, and the temperature measuring unit is detachably arranged on the mounting opening;

[0021] Preferably, the temperature measuring unit comprises a temperature measuring block and a temperature sensor, the temperature measuring block is provided with a temperature measuring channel penetrating the temperature measuring block, one end of the temperature measuring channel is connected to the gas channel of the heating unit, and the other end is connected to the spline housing, and the temperature measuring end of the temperature sensor is inserted into the temperature measuring channel;

[0022] Preferably, the temperature measuring block is a columnar structure, the temperature measuring channel runs through both ends of the columnar structure, a mounting channel connecting the inside and outside of the temperature measuring channel is opened on the surrounding side wall of the columnar structure, and the temperature sensor is inserted in the mounting channel.

[0023] Furthermore, it also includes a heat-insulating shell having an installation cavity inside, and the heating unit is arranged in the installation cavity of the heat-insulating shell.

[0024] Furthermore, the spline housing has a transparent side wall, and an opening penetrating the transparent side wall is formed on the transparent side wall;

[0025] Preferably, the spline housing is a heat-insulating spline housing.

[0026] Furthermore, the stretching fixture comprises a first plate-like structure having columnar protrusions on the surface, and a second plate-like structure having through holes on the surface, wherein the through holes can be sleeved on the columnar protrusions.

[0027] The two ends of the spline are respectively provided with sleeve holes, and the sleeve holes at the two ends are respectively sleeved on the columnar protrusions of the first plate-like structure on the stretching fixture, and the second plate-like structure is sleeved on the columnar protrusions to clamp the end of the spline between the first and second plate-like structures;

[0028] Preferably, the first plate-like structure is provided with a clamping side wall with columnar protrusions, and the second plate-like structure and the contact surface of the clamping side wall and the spline are all provided with anti-slip patterns;

[0029] Preferably, the spline comprises a clamping section located at both ends and can be clamped between the first and second plate-like structures, and a stretching section located between the clamping sections, and the width of the stretching section is smaller than the width of the clamping section;

[0030] Preferably, the clamping section and the stretching section are connected by a gradual transition;

[0031] Preferably, the length of the stretching section is 2 mm.

[0032] The present invention also provides a control method for a stretching device as described in any one of the above technical solutions, comprising: controlling the stretching device to perform bidirectional stretching on a spline clamped in a spline housing;

[0033] Preferably, during the biaxial stretching process, the heating unit is controlled to be turned on, and the heating temperature is 25-170°C;

[0034] Preferably, the biaxial stretching includes uniform linear stretching, and the stretching rate ranges from 0.001 to 100 mm / s;

[0035] Preferably, the biaxial stretching comprises sinusoidal reciprocating stretching with an amplitude of 0.1-100 mm and a frequency of 0.001-10 Hz;

[0036] Preferably, during the spline stretching recovery process, when the force value of the spline reaches the minimum force value of 0.1N, the spline is controlled to stop recovering and the next sinusoidal reciprocating cycle stretching is performed.

[0037] After adopting the above technical scheme, the present invention has the following beneficial effects compared with the prior art.

[0038] In the present invention, two driving mechanisms are turned on to drive the slide to move, the slide movement drives the stretching fixture to move, and the stretching fixture performs bidirectional stretching on the spline, so that the deformation of the spline is more uniform, and has a wider stretching rate range and multiple movement modes.

[0039] In the present invention, the blowing unit can pass gas into the gas channel of the heating unit, and the heating structure of the heating unit heats the passed gas. The high-temperature gas formed after heating can enter the spline shell to heat the entire spline, making its heating and stretching deformation more uniform.

[0040] The gas channel is formed by the holes on the heat conductive block, so that the gas in the gas channel can be heated by the heat conductive block itself, with high heating efficiency, and the gas is heated evenly. When the evenly heated gas acts on the spline, it can heat the spline more evenly.

[0041] A spiral heat-conducting wire is arranged in the gas channel, which increases the residence time of the gas flow in the gas channel to further ensure that the gas can be fully heated.

[0042] The gas heated in the gas channel will first enter the temperature measuring hole for temperature measurement, and then enter the spline shell. The temperature measuring end of the temperature sensor is inserted in the temperature measuring hole, so that the temperature sensor can directly detect the actual temperature of the gas in the temperature measuring hole, and the detection result is accurate. This helps to accurately control the heating temperature of the gas, and then accurately control the heating temperature of the spline.

[0043] In the control method of the stretching device of the present invention, the spline is bidirectionally stretched, the deformation of the spline is more uniform, and the spline has a wider stretching rate range and multiple movement modes.

[0044] The specific implementation modes of the present invention are further described in detail below in conjunction with the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0045] The accompanying drawings are part of the present invention and are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention, but do not constitute an improper limitation of the present invention. Obviously, the drawings described below are only some embodiments. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work. In the accompanying drawings:

[0046] Figure 1 This is a schematic diagram of the explosion structure of the stretching device of the present invention;

[0047] Figure 2 For the present invention Figure 1 A schematic diagram of the local enlarged structure at point A in the middle;

[0048] Figure 3It is a schematic diagram of the exploded structure of the stretching device of the present invention from another angle;

[0049] Figure 4 For the present invention Figure 3 A schematic diagram of the local enlarged structure at B in the middle;

[0050] Figure 5 It is a schematic diagram of the assembly structure of the stretching device of the present invention;

[0051] Figure 6 It is the relationship curve between the setting temperature and the cavity temperature;

[0052] Figure 7 It is the relationship curve between displacement and force value of uniform linear stretching and time;

[0053] Figure 8 This is the relationship curve between the displacement and force value of sinusoidal reciprocating stretching and time.

[0054] In the figure,

[0055] 1. spline shell; 11. cavity; 12. transparent side wall; 121. opening; 13. mounting port; 2. heating unit; 21. gas channel; 22. heat conductive block; 221. first block; 222. second block; 23. heating structure; 3. temperature measuring unit; 31. temperature measuring block; 311. temperature measuring channel; 312. mounting channel; 313. fixing hole; 32. temperature sensor; 4. air blowing unit; 41. air inlet duct; 42. mounting part; 5. heat insulating shell; 6. servo motor; 7. coupling; 8. force sensor; 9. stretching fixture; 10. spline; 101. slide; 102. ball screw; 103. mounting base.

[0056] It should be noted that these drawings and textual descriptions are not intended to limit the conceptual scope of the present invention in any way, but are intended to illustrate the concept of the present invention for those skilled in the art by referring to specific embodiments. DETAILED DESCRIPTION

[0057] In order to make the purpose, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. The following embodiments are used to illustrate the present invention but are not used to limit the scope of the present invention.

[0058] In the description of the present invention, it should be noted that the terms "up", "down", "front", "back", "left", "right", "vertical", "inside", "outside", etc. indicate directions or positional relationships based on the directions or positional relationships shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific direction, be constructed and operated in a specific direction. Therefore, they cannot be understood as limitations on the present invention.

[0059] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0060] Embodiment 1

[0061] like Figures 1 to 5 As shown, the present invention discloses a stretching device, comprising: a mounting base 103, two slides 101 arranged opposite to each other, and the slides 101 are slidably arranged on the mounting base 103. The two slides 101 are respectively provided with a stretching fixture 9 for stretching the spline 10, and the two slides 101 are respectively connected to a driving mechanism, which can drive the slides 101 to slide, and the sliding of the slides 101 drives the stretching fixture 9 to bidirectionally stretch the spline 10. Among them, the mounting base 103 is a strip structure, and the driving mechanism is a servo motor 6, which is respectively arranged at both ends of the mounting base 103.

[0062] In the present invention, two driving mechanisms are turned on to drive the slide 101 to move, and the movement of the slide 101 drives the stretching fixture 9 to move. The stretching fixture 9 performs bidirectional stretching on the spline 10, so that the deformation of the spline 10 is more uniform, and has a wider stretching rate range and multiple movement modes.

[0063] As an implementation of this embodiment, the power output shaft of the driving mechanism is connected to the slide 101 through a ball screw 102, and the ball screw 102 converts the rotational motion of the power output shaft into linear motion to drive the slide 101 to slide.

[0064] Furthermore, the stretching device further comprises a spline housing 1 and two couplings 7. The spline housing 1 is arranged on a mounting base 103 and has a cavity 11 therein for accommodating the spline 10. The two couplings 7 are respectively arranged on both sides of the spline housing 1, between the spline housing 1 and the servo motor 6, and one end of the couplings 7 is connected to the motor shaft of the servo motor 6.

[0065] The ball screw 102 is respectively arranged on both sides of the spline housing 1, located between the spline housing 1 and the coupling 7, and one end thereof is connected to the other end of the coupling 7. The slide 101 is respectively arranged on both sides of the spline housing 1, located between the spline housing 1 and the ball screw 102, and the other end of the ball screw 102 is connected to the slide 101. The stretching clamp 9 is respectively arranged on the slide 101, and is used to clamp the spline 10. The heating unit 2 has a gas channel 21 connected to the spline housing 1 and a heating rod 23 for heating the gas in the gas channel 21. The blast unit 4 is connected to the gas channel 21, and is used to pass gas into the gas channel 21.

[0066] In this embodiment, the servo motors 6 at both ends of the mounting base 103 are turned on to drive the ball screw 102 to move. The ball screw 102 converts the circular motion into the linear motion of the slide 101. The movement of the slides 101 on both sides of the spline housing 1 drives the stretching clamp 9 to move. The stretching clamp 9 clamps the two ends of the spline 10 to perform bidirectional stretching on the spline 10. During the stretching process, the gas output by the blast unit 4 enters the gas channel 21, is heated by the heating structure 23, and is input into the cavity 11 of the spline housing 1 to heat the spline 10.

[0067] In the present invention, the blowing unit 4 can pass gas into the gas channel 21 of the heating unit 2, and the heating structure 23 of the heating unit 2 heats the passed gas. The high-temperature gas formed after heating can enter the spline shell 1, heat the entire spline 10, and make its tensile deformation more uniform.

[0068] As an implementation of this embodiment, the heating unit 2 includes a heat conductive block 22. The heat conductive block 22 is provided with a channel penetrating the heat conductive block 22, and the channel forms the gas channel 21. The heat conductive block 22 is made of a thermally conductive material, for example, the heat conductive block 22 is a copper heat conductive block 22.

[0069] In this embodiment, the gas channel 21 is formed by the holes on the heat conductive block 22, so that the gas in the gas channel 21 can be heated by the heat conductive block 22 itself, with high heating efficiency, and the gas is heated evenly. When the evenly heated gas acts on the spline 10, it can heat the spline more evenly.

[0070] More specifically, the heat conducting block 22 is a columnar structure, and the gas channel 21 extends from one end of the columnar structure to the other end and passes through both ends of the columnar structure.

[0071] The formation method of the gas channel 21 is simple, and the setting method of the gas channel 21 fully and reasonably utilizes the heat conductive block 22. From the time the gas enters the gas channel 21 to the time the gas is discharged from the gas channel 21, the gas is heated by the heat conductive block 22 throughout the entire journey, and the heating is sufficient.

[0072] More specifically, a spiral heat-conducting wire is provided in the gas channel 21. Preferably, the spiral heat-conducting wire is a spiral copper wire. The spiral heat-conducting wire is provided to increase the residence time of the gas flow in the gas channel 21, so as to further ensure that the gas can be fully heated.

[0073] As another implementation of this embodiment, the heat conducting block 22 further has a mounting portion, and the heating structure 23 is disposed on the mounting portion.

[0074] In this embodiment, the heating structure 23 emits heat, and the heat can be conducted to the gas channel 21 through the heat-conducting block 22 with heat-conducting properties, so as to heat the gas in the gas channel 21 .

[0075] Furthermore, the heat conducting block 22 includes a first block 221 and a second block 222 which are divided from one end to the other end. The dividing surfaces of the first block 221 and the second block 222 respectively have groove structures, which are buckled to form the mounting portion, and the heating structure 23 is inserted in the mounting portion.

[0076] Preferably, the mounting portion is a columnar structure. The heating structure 23 is a rod-shaped structure, which is inserted into the mounting portion and is surrounded by metal indium so that it is in full contact with the mounting portion and directly transfers the generated heat to the heat-conducting block 22 .

[0077] In this embodiment, the heating structure 23 is inserted inside the heat-conducting block 22, so that all the heat emitted by the heating structure 23 can be transferred to the heat-conducting block 22; further, the heat-conducting block 22 performs efficient heat transfer, heats the gas in the gas channel 21, and avoids heat loss and waste. In addition, the extension direction of the heating structure 23 in the present invention is the same as that of the gas channel 21, so that the heat emitted by the heating structure 23 can be evenly transferred to the entire gas channel 21, so that the gas in the gas channel 21 is evenly heated.

[0078] As another implementation of this embodiment, the stretching device further includes a temperature measuring unit 3. The temperature measuring unit 3 is arranged between the heating unit 2 and the spline housing 1, and is used to detect the temperature of the heating unit 2.

[0079] Specifically, a mounting opening 13 is provided on the top wall of the spline housing 1, and the temperature measuring unit 3 is detachably arranged on the mounting opening 13. Further, the mounting opening 13 is a circular through hole, and the lower end of the temperature measuring unit 3 is inserted into the mounting opening 13.

[0080] In this embodiment, the temperature measuring unit 3 is provided to monitor the temperature of the heating unit 2 in real time, thereby monitoring the temperature of the gas in the gas channel 21 .

[0081] More specifically, the temperature measuring unit 3 includes a temperature measuring block 31 and a temperature sensor 32. The temperature measuring block 31 is provided with a temperature measuring channel 311 penetrating the body of the temperature measuring block 31, one end of the temperature measuring channel 311 is connected to the gas channel 21 of the heating unit 2, and the other end is connected to the spline housing 1, and the temperature measuring end of the temperature sensor 32 is inserted into the temperature measuring channel 311.

[0082] Furthermore, the temperature measuring block 31 is a columnar structure, the temperature measuring channel 311 runs through both ends of the columnar structure, and a mounting channel 312 connecting the inside and outside of the temperature measuring channel is opened on the surrounding side wall of the columnar structure, and the temperature sensor 32 is inserted into the mounting channel 312.

[0083] In addition, a fixing hole 313 is also provided on the lower end wall of the temperature measuring block 31. Two screw holes are provided on both sides of the temperature measuring hole on the temperature measuring block 31, and two screw holes are also provided on both sides of the gas channel 21 on the heat conducting block 22. The screw structure passes through the two screw holes on the temperature measuring block 31 and is threadedly connected with the screw holes on the heat conducting block 22, and the screw head of the screw structure is located in the fixing hole 313.

[0084] In the present invention, the gas heated in the gas channel 21 will first enter the temperature measuring hole 311 for temperature measurement, and then enter the spline housing 1, and the temperature measuring end of the temperature sensor 32 is inserted in the temperature measuring hole 311, so that the temperature sensor 32 can directly detect the actual temperature of the gas in the temperature measuring hole 311, and the detection result is accurate, which helps to accurately control the heating temperature of the gas, and then accurately control the heating temperature of the spline 10.

[0085] As an embodiment of the present invention, the stretching device further comprises a heat-insulating shell 5 having an installation cavity therein, and the heating unit 2 is arranged in the installation cavity of the heat-insulating shell 5. The heat-insulating shell 5 can be made of polyetheretherketone material.

[0086] In this embodiment, the heat-insulating shell 5 has the function of heat preservation and heat insulation, and the heating unit 2 is arranged in the heat-insulating shell 5, which can prevent the heating unit 2 from scalding the staff.

[0087] Further, the air blowing unit 4 includes an air inlet duct 41 and a mounting portion 42, and the mounting portion 42 is a plate-shaped structure. The air outlet of the air inlet duct 41 is inserted on the mounting portion 42 and integrated with the mounting portion 42, and the mounting portion 42 integrated with the air inlet duct 41 is detachably arranged on the top of the heat insulation shell 5. The air outlet of the air inlet duct 41 is connected to the gas channel 21, and is used to let air into the gas channel 21.

[0088] The blowing unit 4 further includes: an air compressor and a gas flow meter. The air compressor fills gas into the air inlet duct 41 . The gas flow meter is arranged on the air inlet duct 41 to detect the gas flow in the air inlet duct 41 .

[0089] In this embodiment, the blowing unit 4 is integrated outside the insulating shell 5, and the installation method is simple. Before the gas enters the gas channel 21, under the insulating effect of the insulating shell 5, the gas will not be disturbed by the heating unit 2, so that the initial temperature of the gas remains consistent, laying the foundation for the subsequent uniformity of the gas temperature rise.

[0090] As an embodiment of the present invention, the spline housing 1 has a transparent side wall 12, and the transparent side wall 12 is provided with an opening 121 penetrating the transparent side wall 12. Preferably, the spline housing 1 is a heat-insulating spline housing 1. Further, the spline housing 1 can be made of polyetheretherketone material, and the transparent side wall 12 can be made of quartz glass.

[0091] In this embodiment, the spline housing 1 has the function of heat preservation and insulation, and when the spline 10 is heated inside the spline housing 1, the staff will not be burned. By providing a transparent side wall 12, it is convenient to monitor the movement state of the spline 10 in real time. The opening 121 of the transparent side wall 12 can allow X-rays to penetrate, so as to characterize the structural evolution process of the spline 10 during the deformation process in real time.

[0092] As an embodiment of the present invention, the stretching fixture 9 is a plate-like structure, and the surface of the plate-like structure in contact with the spline 10 is roughened to prevent the spline 10 from slipping during the stretching process.

[0093] Furthermore, a cylindrical protrusion is provided on the plate-like structure of the stretching fixture 9. Both ends of the spline 10 are extended and punched, and the spline 10 is fixed on the cylindrical protrusion of the plate-like structure of the stretching fixture 9 through the holes, so that the spline 10 is fixed, especially for the polymer spline 10 with a smooth surface, the fixation is more convenient.

[0094] As an implementation of this embodiment, a force sensor 8 is provided on the slide 101 to detect the pulling force of the slide 101 on the spline 10. The stretching device also includes a controller, which can accurately control the movement of the servo motor 6 to achieve multiple modes of uniform linear stretching and sinusoidal reciprocating stretching.

[0095] In this embodiment, the uniform linear stretching motion has a wide range of stretching rates; the amplitude, frequency and number of oscillations of the sinusoidal reciprocating stretching can be set. At the same time, the values ​​of the force sensor 8 and the temperature sensor 32 are transmitted to the controller in real time, and the controller reads the data fed back by the force sensor 8 and the temperature sensor 32 in real time, and plots and saves them.

[0096] As another implementation of this embodiment, the stretching fixture 9 includes a first plate-like structure with columnar protrusions on the surface, and a second plate-like structure with through holes on the surface, and the through holes can be sleeved on the columnar protrusions. The two ends of the spline 10 are respectively provided with sleeve holes, and the sleeve holes at the two ends are respectively sleeved on the columnar protrusions of the first plate-like structure on the two slides, and the second plate-like structure is sleeved on the columnar protrusions to clamp the end of the spline between the first and second plate-like structures. The stretching fixture 9 of this embodiment has a good fixing effect on polymer samples with smooth surfaces.

[0097] Furthermore, the first plate-like structure is provided with a clamping side wall with columnar protrusions, and the second plate-like structure and the contact surface between the clamping side wall and the spline are provided with anti-slip patterns to prevent the spline 10 from slipping during the stretching process.

[0098] The spline 10 includes a clamping section located at both ends and can be clamped between the first and second plate-like structures, and a stretching section located between the clamping sections, wherein the width of the stretching section is smaller than the width of the clamping section. Preferably, the clamping section and the stretching section are connected by a gradually contracting transition; more preferably, the length of the stretching section is 2 mm, and the total length of the spline 10 is 30 mm.

[0099] The present invention redesigns the spline 10, and the design is designed for bidirectional stretching of the spline 10 using the stretching device of the present invention. The spline 10 of the present invention is convenient for fixed stretching, and the stretching section of the spline 10 is short in length and small in width, which is conducive to being fully and evenly heated, making the deformation more uniform, and achieving a faster deformation rate.

[0100] Furthermore, the stretching device also includes a high-speed camera. Marking points are marked on the surface of the spline 10, and the high-speed camera monitors the stretching process of the spline 10 in real time. The actual strain of the spline 10 during the stretching process can be obtained by analyzing the marking points on the spline 10 later.

[0101] Embodiment 2

[0102] This embodiment provides a control method for a stretching device as described in any of the above technical solutions, controlling the stretching device to perform bidirectional stretching on the spline 10 clamped in the spline housing 1 .

[0103] Specifically, Figure 5 As shown, the servo motors 6 at both ends of the mounting base 103 are controlled to start, driving the ball screw 102 to move. The ball screw 102 converts the circular motion into the linear motion of the slide 101. The movement of the slide 101 on both sides of the spline housing 1 drives the stretching clamp 9 to move. The stretching clamp 9 clamps the two ends of the spline 10 to perform bidirectional stretching on the spline 10.

[0104] When biaxial stretching is performed, the blast unit 4 is controlled to pass gas into the gas channel 21 of the heating unit 2; the heating structure 23 of the heating unit 2 is controlled to open to heat the passed gas; the high-temperature gas formed after heating enters the spline housing 1 to heat the entire spline 10, making its stretching deformation more uniform. The heating temperature of the heating unit is 25-170°C.

[0105] During the stretching process, the data fed back by the force sensor 8 and the temperature sensor 32 are monitored in real time; the air intake of the blower unit 4 is controlled to be constant by fixing the gas flow rate through a gas flow meter; the heating temperature of the heating structure 23 is controlled according to the temperature detected by the temperature sensor 32 so as to control the heating temperature to reach the experimental temperature; the tensile load borne by the spline 10 is monitored in real time according to the force sensor 8.

[0106] During the stretching process, the control transmits the values ​​of the force sensor 8 and the temperature sensor 32 to the controller in real time. The controller reads the data fed back by the force sensor 8 and the temperature sensor 32 in real time, draws a graph and saves it.

[0107] As an implementation method of this embodiment, Figure 6 The relationship curve between the set temperature and the cavity temperature is shown in FIG. 1 , wherein the set temperature is the preset temperature to be heated, and the cavity temperature is the temperature in the cavity 11. Figure 6 It can be seen that the stretching equipment of the present invention can accurately control the temperature in the cavity 11 to be the same as the set temperature, thereby improving the accuracy of the stretching test.

[0108] As an implementation of this embodiment, the biaxial stretching includes uniform linear stretching, and the stretching rate is 0.001-100 mm / s. The uniform linear stretching has a wide stretching rate, which can meet the testing requirements of polymer materials at different deformation rates.

[0109] Further, for example, when the stretching rate is controlled to be 0.25 mm / s and the temperature is 30°C, the following is obtained: Figure 7 The relationship between displacement and force value over time is shown in Figure 7 It can be seen that as time goes by, the force value and displacement of the spline 10 increase uniformly, and the deformation is uniform.

[0110] As another implementation of this embodiment, the bidirectional stretching includes sinusoidal reciprocating stretching, with an amplitude of 0.1-100 mm, a frequency of 0.001-10 Hz, and an oscillation number of 0-∞. Further, during the stretching and recovery process of the spline 10, when the force value of the spline 10 reaches the minimum force value of 0.1 N, the spline is controlled to stop recovering and the next sinusoidal reciprocating cycle stretching is performed.

[0111] For example, when the control amplitude is 30mm, the frequency is 0.01Hz, and the temperature is 30℃, the following is obtained: Figure 8 The relationship between displacement and force value over time is shown in Figure 8 It can be seen that the sinusoidal reciprocating stretching realizes cyclic dynamic stretching and meets the scientific research needs of polymer materials in sinusoidal reciprocating stretching. Furthermore, when the force value of the spline reaches the minimum force value of 0.1N, the spline stops recovering and continues the next sinusoidal reciprocating cycle stretching, thereby avoiding the bending of the spline 10 in the cyclic reciprocating motion and affecting the test.

[0112] The above is only a preferred embodiment of the present invention, and does not limit the present invention in any form. Although the present invention has been disclosed as a preferred embodiment as above, it is not used to limit the present invention. Any technician familiar with this patent can make some changes or modify the technical contents suggested above into equivalent embodiments without departing from the scope of the technical solution of the present invention. However, any simple modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention still fall within the scope of the solution of the present invention.

Claims

1. A stretching device, comprising: A mounting base and two slides arranged opposite to each other, the slides are slidably arranged on the mounting base, and the two slides are respectively provided with stretching clamps for stretching splines, characterized in that: the two slides are respectively connected to a driving mechanism, the driving mechanism can drive the slides to slide, and the sliding of the slides drives the stretching clamps to bidirectionally stretch the splines.

2. A stretching device according to claim 1, characterized in that: The power output shaft of the driving mechanism is connected to the slide table through a ball screw, and the ball screw converts the rotary motion of the power output shaft into linear motion, which is used to drive the slide table to slide.

3. A stretching device according to claim 1 or 2, characterized in that: Also includes: A spline housing having a cavity therein for accommodating the spline; a heating unit having a gas channel connected to the spline housing and a heating structure for heating the gas in the gas channel; a blast unit, connected to the gas passage, and used for introducing gas into the gas passage; The gas outputted by the blowing unit enters the gas channel, is heated by the heating structure, and then is inputted into the cavity of the spline housing to heat the spline.

4. A stretching device according to claim 3, characterized in that: The heating unit comprises a heat-conducting block, on which a hole penetrating the heat-conducting block is provided, and the hole forms the gas channel; The heat conducting block is a columnar structure, and the gas channel extends from one end of the columnar structure to the other end and passes through both ends of the columnar structure; Preferably, a spiral heat-conducting wire is provided in the gas channel.

5. A stretching device according to claim 4, characterized in that: The heat conducting block also has a mounting portion, and the heating structure is arranged on the mounting portion; Preferably, the heat conductive block comprises first and second blocks divided from one end to the other end, and the dividing surfaces of the first and second blocks respectively have groove structures, which are buckled to form the mounting portion, and the heating structure is inserted into the mounting portion.

6. A stretching device according to any one of claims 3 to 5, characterized in that: It also includes a temperature measuring unit, which is arranged between the heating unit and the spline housing and is used to detect the temperature of the blown hot air; Preferably, a mounting opening is provided on the top wall of the spline housing, and the temperature measuring unit is detachably arranged on the mounting opening; Preferably, the temperature measuring unit comprises a temperature measuring block and a temperature sensor, the temperature measuring block is provided with a temperature measuring channel penetrating the temperature measuring block, one end of the temperature measuring channel is connected to the gas channel of the heating unit, and the other end is connected to the spline housing, and the temperature measuring end of the temperature sensor is inserted into the temperature measuring channel; Preferably, the temperature measuring block is a columnar structure, the temperature measuring channel runs through both ends of the columnar structure, a mounting channel connecting the inside and outside of the temperature measuring channel is opened on the surrounding side wall of the columnar structure, and the temperature sensor is inserted in the mounting channel.

7. A stretching device according to any one of claims 3 to 6, characterized in that: It also includes a heat-insulating shell with an installation cavity inside, and the heating unit is arranged in the installation cavity of the heat-insulating shell.

8. A stretching device according to any one of claims 3 to 7, characterized in that: The spline housing has a transparent side wall, and an opening penetrating the transparent side wall is formed on the transparent side wall; Preferably, the spline housing is a heat-insulating spline housing.

9. A stretching device according to any one of claims 1 to 8, characterized in that: The stretching fixture comprises a first plate-like structure having a columnar protrusion on the surface, and a second plate-like structure having a through hole on the surface, wherein the through hole can be sleeved on the columnar protrusion. The two ends of the spline are respectively provided with sleeve holes, and the sleeve holes at the two ends are respectively sleeved on the columnar protrusions of the first plate-like structure on the two slides, and the second plate-like structure is sleeved on the columnar protrusions to clamp the end of the spline between the first and second plate-like structures; Preferably, the first plate-like structure is provided with a clamping side wall with columnar protrusions, and the second plate-like structure and the side wall opposite to the clamping side wall are all provided with anti-slip patterns on the contact surface with the spline; Preferably, the spline comprises a clamping section located at both ends and can be clamped between the first and second plate-like structures, and a stretching section located between the clamping sections, and the width of the stretching section is smaller than the width of the clamping section; Preferably, the clamping section and the stretching section are connected by a gradual transition; Preferably, the length of the stretching section is 2 mm.

10. A control method for a stretching device according to any one of claims 1 to 9, characterized in that: Controlling the stretching device to perform bidirectional stretching on the spline clamped in the spline housing; Preferably, during the biaxial stretching process, the heating unit is controlled to be turned on, and the heating temperature is 25-170°C; Preferably, the biaxial stretching includes uniform linear stretching, and the stretching rate ranges from 0.001 to 100 mm / s; Preferably, the biaxial stretching comprises sinusoidal reciprocating stretching with an amplitude of 0.1-100 mm and a frequency of 0.001-10 Hz; Preferably, during the spline stretching recovery process, when the force value of the spline reaches the minimum force value of 0.1N, the spline is controlled to stop recovering and the next sinusoidal reciprocating cycle stretching is performed.

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