A strength testing machine for injection molded parts

Abstract

This invention relates to the field of injection molded part testing technology, specifically to an injection molded part strength testing machine. The machine includes a frame, a testing platform for placing the part to be tested on the frame, a gantry frame on the testing platform, and an electric push rod vertically downwards mounted on the gantry frame. An installation platform is fixedly mounted on the output end of the electric push rod. A first airbag is positioned below the installation platform, and multiple pressure sensors are fixedly mounted on the side of the first airbag facing the testing platform. A gas supply assembly for providing pressurized gas to the first airbag is fixedly mounted on the top of the gantry frame. This invention, by fixing multiple pressure sensors to the first airbag and utilizing the principle that the first airbag deforms when inflated, allows multiple pressure sensors to simultaneously conform to the curved surface of the part. This enables the injection molded part strength testing machine to simultaneously perform strength tests on multiple points on the injection molded part, effectively improving testing efficiency.

Description

Technical Field

[0001] This invention relates to the field of injection molded part testing technology, specifically to an injection molded part strength testing machine. Background Technology

[0002] Injection molded parts are components formed by injecting molten plastic into a mold and then cooling it to solidify. Before mass production, injection molded parts typically undergo strength tests to ensure they meet the required strength for use.

[0003] Existing injection molded part strength testing machines typically use an electric or hydraulic pusher to drive a testing head equipped with a pressure sensor to compress the injection molded part from top to bottom. Under the continuous pressure of the testing head, the injection molded part eventually breaks. The pressure value detected by the pressure sensor at the time of breakage is then read to determine whether the strength of the injection molded part meets expectations. The experimenter then uses the test results to determine whether the design of the injection molded part needs optimization. For example, Chinese utility model patent application number CN202022862014.8, entitled "An Injection Molded Part Strength Testing Machine," utilizes the above principle to test injection molded parts.

[0004] However, existing injection molding strength testing machines only have one testing head when testing injection molded parts. The tester can only select one point on the injection molded part for testing. After testing one point, the part needs to be replaced and another point needs to be selected for testing, resulting in low testing efficiency. Although multiple testing heads can be added to achieve simultaneous testing of multiple points for flat parts, for parts with more complex shapes, such as shell parts with a certain curvature, simply increasing the number of testing heads is insufficient to achieve simultaneous testing.

[0005] Therefore, a strength testing machine for injection molded parts is proposed. Summary of the Invention

[0006] The purpose of this invention is to provide an injection molding strength testing machine that solves the problem mentioned in the background art that existing injection molding strength testing machines cannot simultaneously perform strength tests on multiple points on arc-shaped shell-like parts.

[0007] To achieve the above objectives, the present invention provides the following technical solution:

[0008] A strength testing machine for injection molded parts includes a frame, a testing platform for placing the parts to be tested on the frame, a gantry frame on the testing platform, an electric push rod vertically downwards on the gantry frame, an installation platform fixedly mounted on the output end of the electric push rod, a first airbag below the installation platform, multiple pressure sensors fixedly mounted on the side of the first airbag facing the testing platform, a gas supply component for supplying pressurized gas to the first airbag fixedly mounted on the top of the gantry frame, a first exhaust valve for discharging gas from the first airbag, and an automatic control system on the frame. The automatic control system includes a processing unit and a display unit. The gas supply component, electric push rod, pressure sensors, first exhaust valve, and display unit are all electrically connected to the processing unit. The display unit displays the pressure values ​​detected by each pressure sensor.

[0009] The electric actuator drives the mounting platform and the first airbag to move up and down. One or more pressure sensors are fixedly installed under the airbag by adhesive bonding. This allows for simultaneous strength testing of multiple points on the injection molded part, or testing of a single point on the injection molded part. When the first airbag inflates, it presses the pressure sensor onto the surface of the injection molded part. The air pressure inside the first airbag continuously increases the load on the injection molded part, while the pressure sensor, clamped between the injection molded part and the first airbag, records the pressure value at the contact point between the pressure sensor and the injection molded part in real time.

[0010] The measurement method can be achieved by setting a predetermined pressure value. If the contact point between the pressure sensor and the injection molded part is not destroyed when the pressure sensor reaches the predetermined pressure value, it indicates that the contact point between the pressure sensor and the injection molded part has reached the expected strength effect. Alternatively, by continuously inflating the first air chamber, the internal pressure of the first air chamber is continuously increased, thereby continuously increasing the compressive force of the pressure sensor on the injection molded part until the contact point between the pressure sensor and the injection molded part is destroyed, thus measuring the ultimate compressive strength of the injection molded part.

[0011] By fixing the pressure sensors below the first airbag, even when testing injection-molded parts with complex surface shapes like curved shells, the expansion of the first airbag ensures that each pressure sensor remains in contact with the surface of the injection-molded part. This guarantees that each pressure sensor can simultaneously and effectively measure the strength of various points on the curved shell injection-molded part. Multiple pressure sensors simultaneously perform strength tests on multiple points on the injection-molded part, improving the testing efficiency of the injection-molded part strength testing machine. Furthermore, simultaneous testing at multiple points allows observation of the overall strength of the injection-molded part under simultaneous pressure at multiple points, facilitating the analysis of the overall strength of the injection-molded part and helping researchers further optimize its structure.

[0012] The first airbag, covering the surface of the injection-molded part, also serves as a protective measure, preventing fragments from flying and injuring people when the injection-molded part breaks, thus improving the safety of the test.

[0013] The processing unit manages the air supply components and adjusts the internal pressure of the airbag according to testing requirements. It also controls the extension and retraction of the electric push rod and the opening and closing of the first exhaust valve during the use of the first airbag. Furthermore, the processing unit receives and records the pressure values ​​detected by each pressure sensor and transmits these values ​​to the display unit for quick access to the data from each sensor, allowing researchers to easily obtain the information.

[0014] Preferably, the installation platform is made of metal, and four side plates made of metal are fixedly installed at the bottom of the installation platform. The four side plates form a rectangular guide space, and the first airbag is located inside the guide space. Before the first airbag is inflated, it is completely contained inside the guide space.

[0015] When the first airbag inflates, the gas expands it in all directions simultaneously. However, this inflates it too rapidly to effectively transmit pressure to the pressure sensor, preventing the sensor from applying pressure to the test piece. By adding side plates to the underside of the mounting platform, these four side plates, working in conjunction with the platform, form a downward-opening rectangular guide space. This restricts the inflation direction of the first airbag, ensuring it only inflates towards the test platform. This guarantees that the pressure sensor can effectively apply pressure to the test piece, thus ensuring the effectiveness of the strength test on the injection-molded part.

[0016] Preferably, on the side of the first airbag facing the test platform, multiple marking components are also provided corresponding to the pressure sensors. Each marking component includes a liquid storage ring fixedly installed on the first airbag. The pressure sensors are all located within the inner ring of their respective liquid storage rings. Multiple connecting pipes are fixedly installed inside the liquid storage rings, with the connecting pipes circumferentially distributed on the liquid storage rings. The ends of the connecting pipes facing the test platform are sealed to the liquid storage rings, and the ends of the connecting pipes facing the electric push rod are located on the upper side inside the liquid storage rings. The connecting pipes connect the liquid storage rings... The internal structure is connected to the external structure of the storage ring. Each storage ring contains a different color of labeling liquid. The liquid level of the labeling liquid in each storage ring is not higher than the end face of the connecting pipe located inside the storage ring. A sliding tube is slidably installed inside the connecting pipe. An absorbent cotton core is installed inside the sliding tube. One end of the absorbent cotton core located inside the storage ring is immersed in the labeling liquid. The end of the absorbent cotton core facing the test platform extends out of the end face of the sliding tube, and the lowest point of the absorbent cotton core is lower than the lowest point of the pressure sensor.

[0017] The absorbent cotton core is made of a loose, porous material. Through capillary action, it absorbs and transfers the marking liquid within the reservoir ring to its lowest point, while preventing the marking liquid from flowing directly out of the connecting tube. The lowest point of the absorbent cotton core is lower than the lowest point of the pressure sensor, ensuring that the marking liquid is applied to the surface of the injection molded part. The sliding tube allows the absorbent cotton core to slide along the connecting tube, allowing it to be squeezed into the reservoir ring by the injection molded part upon contact. This prevents the pressure sensor from failing to make contact with the injection molded part surface after the absorbent cotton core comes into contact, ensuring the stable operation of the equipment.

[0018] By arranging multiple absorbent cotton cores around the pressure sensor, and marking the contact point between the pressure sensor and the molded part with colored marker liquid as the pressure sensor compresses the molded part, the location of the contact can be identified by the different colors of the marker liquid when the molded part is crushed at the pressure sensor location. This allows for a quick assessment of the pressure applied at that point. This improves the ease of use of the equipment and further enhances the efficiency of the testing.

[0019] The labeling solution is transferred through an absorbent cotton core. When the reservoir ring is tilted, the absorbent cotton core can block the connecting tube, preventing a large amount of labeling solution from flowing out of the reservoir ring from the connecting tube.

[0020] Preferably, a visual inspection camera is installed on the gantry frame. The visual inspection camera is electrically connected to the processing unit and is used to identify the damage location on the inspected part and the color of the damage location. By identifying the damage location of the injection molded part and the different marking liquids at the damage location through the visual inspection camera, and automatically determining which pressure sensor corresponds to the damage location based on the different colors of the marking liquids, the corresponding sensor value is automatically read. This enables automatic judgment of test results and helps improve the intelligence of the equipment.

[0021] Preferably, a rubber sheet is fixedly mounted on the end face of the pressure sensor facing the test platform. The rubber sheet is used to increase the friction between the pressure sensor and the test piece. Increasing the pressure between the pressure sensor and the test piece, i.e., increasing the pressure between the pressure sensor and the injection molded part under test, through the rubber sheet helps the pressure sensor to be quickly and stably positioned on the surface of the injection molded part. This prevents the pressure sensor from continuously sliding on the surface of the injection molded part during the inflation and deformation of the first airbag, which could lead to overlapping colors of the marking components. This ensures that after the test, the test personnel can quickly identify the pressure sensor corresponding to the test position, thus quickly determining the data for the test position.

[0022] Preferably, the thickness of the side of the first airbag facing the test platform is 1cm to 1.5cm, and the thickness of the sidewall of the first airbag is 1 / 3 of the thickness of the side of the first airbag facing the test platform.

[0023] The first airbag is made of soft natural rubber, with a thickness of 1cm to 1.5cm on the side facing the test platform. This design ensures that the side of the first airbag facing the test platform has a certain degree of deformability, allowing the pressure sensor to adhere to the surface of the injection molded part. However, it also prevents excessive deformation of the first airbag facing the test platform, which could lead to complete adhesion between the airbag and the injection molded part surface. This avoids pressure dispersion due to complete adhesion, which would reduce the pressure exerted by the pressure sensor on the injection molded part surface and be detrimental to the strength testing of the injection molded part at the pressure sensor location.

[0024] Meanwhile, the 1cm to 1.5cm thick rubber makes the installation and fixation of the pressure sensor more convenient, and also avoids the side of the first airbag facing the test platform being too thin. This prevents the edge of the injection molded part from scratching the surface of the first airbag after the injection molded part is damaged, thus avoiding air leakage and ensuring the service life of the equipment.

[0025] The sidewall thickness of the first airbag is chosen to be one-third of the thickness of the side facing the test platform. This is because the first airbag mainly needs to expand and deform downwards. Therefore, a thinner sidewall facilitates the downward deformation of the first airbag, allowing it to expand more quickly and ensuring a faster response speed. Simultaneously, since the outer side plate of the first airbag restricts its horizontal expansion, the deformation of the first airbag's side is mainly downward elongation. Furthermore, when the pressure sensor contacts the injection molded part surface, the downward elongation of the first airbag's side is also limited. Therefore, there is no need to worry about the first airbag's side rupturing due to excessive elongation.

[0026] Preferably, the guide space is provided with an annular second airbag, which is connected to the air supply component. The second airbag is fixedly installed on the lower side of the four side plates. The second airbag is provided with a second exhaust valve, which is electrically connected to the processing unit. When the second airbag is inflated, it expands horizontally toward the center of the guide space.

[0027] After the second airbag inflates, it expands horizontally towards the center of the guide space, which can limit the horizontal displacement of the injection molded part under test on the test platform, prevent the injection molded part from sliding after being squeezed during the test, and further prevent the colors marked by the marking component from overlapping. At the same time, it can also help the pressure sensor to quickly position itself on the surface of the injection molded part under test, facilitating the test.

[0028] Preferably, the side of the first airbag facing the test platform is provided with a wear-resistant layer. The wear-resistant layer helps to further prevent the first airbag from being scratched by the sharp edges of the injection molded part, prevents the first airbag from leaking air during inflation, and helps to further improve the service life of the first airbag.

[0029] Preferably, a sound pickup unit is provided inside the guide space. The sound pickup unit is fixedly installed on one of the side plates and is electrically connected to the processing unit. The sound pickup unit is used to identify the sound of the tested part breaking. When the sound pickup unit detects that the tested injection molded part has broken, it feeds back an electrical signal to the processing unit. The processing unit controls the equipment to reset, and the visual inspection camera determines the location of the breakage and the data measured by the pressure sensor at that location. No manual assistance is required to determine when the injection molded part breaks, realizing unmanned automatic testing. The intelligent sensing system composed of pressure sensor, visual inspection camera, sound pickup sensor and processing unit further improves the intelligent detection of the strength of injection molded parts.

[0030] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0031] 1. Compared with existing injection molding strength testing machines, the injection molding strength testing machine designed in this invention, by fixing multiple pressure sensors on the first air bladder and utilizing the principle that the first air bladder can deform when inflated, allows multiple pressure sensors to simultaneously adhere to the surface of the arc-shaped part, enabling the injection molding strength testing machine to simultaneously perform strength tests on multiple points on the injection molding part, effectively improving the efficiency of the test.

[0032] 2. The injection molding strength testing machine designed in this invention is also equipped with multiple marking components. The marking components mark the test positions on the injection molding parts with different colors when the pressure sensor performs the strength test on the injection molding parts. This makes it easy for the test personnel to quickly understand the pressure sensor corresponding to the test position after the test is completed, and to quickly read the pressure sensor value at the corresponding position, thereby improving the ease of use of the equipment.

[0033] 3. The injection molding strength testing machine designed in this invention is also equipped with a visual inspection camera and a sound pickup unit. The sound pickup unit monitors the sound of the injection molding part breaking, and the visual inspection camera identifies the location of the breakage and the color at the location of the breakage. The data of the pressure sensor corresponding to the location of the breakage is automatically read, thereby realizing automatic reading of the test results and improving the intelligence of the injection molding strength testing machine. Attached Figure Description

[0034] Figure 1 This is a three-dimensional structural diagram of the present invention;

[0035] Figure 2This is a front view of the present invention;

[0036] Figure 3 This is a schematic diagram of the internal space of the guide space during the experiment of this invention;

[0037] Figure 4 For the present invention Figure 3 Enlarged view of point A in the middle;

[0038] Figure 5 For the present invention Figure 4 Enlarged view of point B in the middle;

[0039] Figure 6 This is a three-dimensional schematic diagram of the relationship between the marking component and the pressure sensor in this invention;

[0040] Figure 7 This is a schematic diagram showing the location of breakage and the marking color on the injection molded part in this invention;

[0041] Figure 8 For the present invention Figure 5 A magnified view of point C in the middle.

[0042] In the diagram: 1. Frame; 2. Test platform; 3. Gantry; 4. Electric push rod; 5. Mounting platform; 6. First airbag; 7. Pressure sensor; 8. Air supply assembly; 9. First exhaust valve; 10. Processing unit; 11. Display unit; 12. Side plate; 13. Guide space; 14. Liquid storage ring; 15. Connecting pipe; 16. Marking liquid; 17. Slide tube; 18. Absorbent cotton core; 19. Visual inspection camera; 20. Rubber sheet; 21. Marking color; 22. Second airbag; 23. Second exhaust valve; 24. Wear-resistant layer; 25. Sound pickup unit; 26. Breakage location. Detailed Implementation

[0043] Please see Figures 1 to 8 This invention provides a strength testing machine for injection molded parts, the technical solution of which is as follows:

[0044] A strength testing machine for injection molded parts, reference Figures 1 to 5The diagram includes a frame 1, on which a test platform 2 for placing the workpiece to be tested is mounted. A gantry frame 3 is mounted on the test platform 2, and an electric push rod 4 is vertically mounted downwards on the gantry frame 3. The electric push rod 4 should be a high-precision, stable model to ensure it can drive the mounting platform 5 and the first airbag 6 up and down according to the set speed and stroke. For example, an electric push rod 4 with a stroke of 300mm and a speed adjustment range of 1-10mm / s can be selected. The output end of the electric push rod 4 is horizontally fixed to the mounting platform 5, which is made of metal. Four metal side plates 12 are vertically welded to the bottom of the mounting platform 5, forming a rectangular guide space 13. The first airbag 6 is located within the guide space 13, and its top is fixed to the bottom surface of the mounting platform 5 by adhesive bonding. Before inflation, the first airbag 6 is completely retracted inside the guide space 13. The thickness of the side of the first airbag 6 facing the test platform 2 is 1cm to 1.5cm. In this embodiment, the thickness of the side of the first airbag 6 facing the test platform 2 is selected as 1cm. The thickness of the sidewall of the first airbag 6 is 1 / 3 of the thickness of the side of the first airbag 6 facing the test platform 2. In addition, a wear-resistant layer 24 is provided on the side of the first airbag 6 facing the test platform 2. The wear-resistant layer 24 is made of wear-resistant rubber coating or other wear-resistant materials and is fixed to the surface of the first airbag 6 by coating or pasting. Three pressure sensors 7 are fixedly installed on the side of the first airbag 6 facing the test platform 2, that is, the bottom surface of the first airbag 6. The three pressure sensors 7 are evenly distributed on the bottom surface of the first airbag 6. The three pressure sensors 7 are all circular spoke-type pressure sensors 7 and are fixedly installed on the bottom surface of the first airbag 6 by adhesive bonding. A rubber sheet 20 is glued and fixedly installed on the end face of each pressure sensor 7 facing the test platform 2. The rubber sheet 20 is used to increase the friction between the pressure sensor 7 and the test piece.

[0045] refer to Figure 1 and Figure 2 A gas supply assembly 8 for supplying pressurized gas to the first airbag 6 is fixedly installed on the top of the gantry frame 3. The gas supply assembly 8 is connected to the first airbag 6 by a hose. The gas supply assembly 8 should have a stable gas pressure output capability and the output gas pressure can be adjusted according to needs, for example, the output gas pressure range is 0MPa~15MPa, and the accuracy is controlled within ±0.1MPa. The first airbag 6 is also equipped with a first exhaust valve 9 for discharging the gas inside the first airbag 6. The first exhaust valve 9 is a solenoid valve. An automatic control system is also installed on the frame 1. The automatic control system includes a processing unit 10 and a display unit 11. The processing unit 10 can be a computer or a single-chip microcomputer system with data processing capabilities, and the display unit 11 can be an LCD screen. The gas supply assembly 8, electric push rod 4, pressure sensor 7, first exhaust valve 9, and display unit 11 are all electrically connected to the processing unit 10.

[0046] refer to Figure 4 The guide space 13 is equipped with a ring-shaped second airbag 22. The second airbag 22 is connected to the air supply component 8 and is supplied with air by the air supply component 8 through a separate hose. The second airbag 22 is fixedly installed on the lower side of the four side plates 12. The second airbag 22 is equipped with a second exhaust valve 23, which is also a solenoid valve. The second exhaust valve 23 is electrically connected to the processing unit 10. When the second airbag 22 is inflated, the second airbag 22 expands horizontally toward the center of the guide space 13.

[0047] refer to Figure 4 , Figure 6 and Figure 8 On the side of the first airbag 6 facing the test platform 2, three marking components are also provided corresponding to the pressure sensor 7. Each marking component includes a liquid storage ring 14 fixedly installed on the first airbag 6. The pressure sensor 7 is located inside the inner ring of the corresponding liquid storage ring 14. Four connecting pipes 15 are fixedly installed inside each liquid storage ring 14. The four connecting pipes 15 are evenly distributed around the circumference of the liquid storage ring 14. The end of the connecting pipe 15 facing the test platform 2 is sealed to the liquid storage ring 14, and the end of the connecting pipe 15 facing the electric push rod 4 is located on the upper side inside the liquid storage ring 14. The connecting pipe 15 connects the inside of the liquid storage ring 14 with the outside of the liquid storage ring 14. Each liquid ring 14 contains a labeling liquid 16, and the color of the labeling liquid 16 stored in each liquid ring 14 is different. The liquid level of the labeling liquid 16 in each liquid ring 14 is not higher than the end face of the connecting pipe 15 located inside the liquid ring 14. A sliding tube 17 is slidably installed inside the connecting pipe 15. An absorbent cotton core 18 is fixed inside the sliding tube 17. One end of the absorbent cotton core 18 located inside the liquid ring 14 extends out of the end face of the connecting pipe 15 and is bent and immersed in the labeling liquid 16. The end of the absorbent cotton core 18 facing the test platform 2 extends out of the end face of the sliding tube 17, and the lowest point of the absorbent cotton core 18 is lower than the lowest point of the pressure sensor 7.

[0048] refer to Figures 1 to 3 A visual inspection camera 19 is installed on the gantry 3. The visual inspection camera 19 is electrically connected to the processing unit 10. The visual inspection camera 19 is used to identify the location of damage on the inspected part and identify the color of the location of damage. A sound pickup unit 25 is installed inside the guide space 13. The sound pickup unit 25 is fixedly installed on one of the side plates 12. The sound pickup unit 25 is electrically connected to the processing unit 10. The sound pickup unit 25 is used to identify the sound of the inspected part breaking.

[0049] In this embodiment, the ultimate strength of the injection molded part is used as an example for illustration.

[0050] During the test, based on the material, shape, and expected strength of the injection molded part being tested, the processing unit 10 sets the operating parameters of the electric push rod 4. For example, the descent speed is set to 5 mm / s, the ascent speed to 8 mm / s, and the stroke is set to an appropriate value according to the height of the injection molded part. Simultaneously, the output pressure parameters of the air supply component 8 are set. When conducting the ultimate compressive strength test, the initial internal inflation pressure of the first airbag 6 is set to 1 MPa, with each inflation pressure increment being 0.5 MPa. The inflation pressure of the second airbag 22 is a constant 0.5 MPa.

[0051] After preparation, refer to Figures 1 to 4 The injection molded part for testing is placed horizontally on the testing platform 2, directly below the guide space 13. The curved surface of the injection molded part faces the airbag. Then, the processing unit 10 controls the electric push rod 4 to extend downwards at a speed of 5 mm / s until the bottom of the side plate 12 contacts the top surface of the testing platform 2, and then the electric push rod 4 is stopped. At this time, the injection molded part is completely inside the guide space 13. Then, the processing unit 10 controls the air supply component 8 to inflate the second airbag 22. After the second airbag 22 expands horizontally, it clamps the side of the injection molded part. When the pressure inside the second airbag 22 reaches 0.5 MPa, the air supply to the second airbag 22 is stopped, and the pressure inside the second airbag 22 is kept stable.

[0052] Subsequently, reference Figures 4 to 6 as well as Figure 8 The processing unit 10 controls the air supply assembly 8 to supply air to the first airbag 6. The first airbag 6, limited by the four side plates 12, can only expand downwards. Three pressure sensors 7 abut against the curved surface of the injection molded part. Rubber sheets 20 on the pressure sensors 7 prevent them from sliding on the surface of the injection molded part. Four absorbent cotton cores 18 around each pressure sensor 7 contact the surface of the injection molded part before the pressure sensor 7 comes into contact with it, marking four colored dots on the surface. The corresponding pressure sensor 7 is located in the middle of these four colored dots. When the pressure sensor 7 contacts the surface of the injection molded part, the absorbent cotton core 18, under the pressure of the injection molded part surface, slides along the connecting pipe 15 with the slide rod and retracts into the liquid storage ring 14 to avoid interference that would prevent the pressure sensor 7 from making smooth contact with the surface of the injection molded part.

[0053] refer to Figure 3 and Figure 4After all three pressure sensors 7 are in contact with the curved surface of the injection molded part, as the air pressure inside the first airbag 6 continuously increases, the bottom surface of the first airbag 6 will deform to a certain extent, causing each pressure sensor 7 to adhere to the curved surface of the injection molded part. Because the thickness of the bottom surface of the first airbag 6 is set to 1 cm, the deformation of the bottom surface of the first airbag 6 is effectively reduced, preventing the bottom surface of the first airbag 6 from adhering to the surface of the injection molded part under gas pressure. Furthermore, the fact that the three pressure sensors 7 are evenly distributed on the bottom surface of the first airbag 6 further prevents the first airbag 6 from adhering to the surface of the injection molded part, ensuring the pressure of the pressure sensors 7 on the injection molded part, thus guaranteeing the effectiveness of the test.

[0054] refer to Figure 4 and Figure 7 As the internal pressure of the first airbag 6 increases, when the injection molded part reaches its limit at the contact point of one of the pressure sensors 7, the injection molded part is broken, producing a "crack" sound. The sound pickup unit 25 detects this sound and transmits an electrical signal to the processing unit 10. Upon receiving the signal from the sound pickup unit 25, the processing unit 10 controls the air supply assembly 8 to stop supplying air to the first airbag 6. Subsequently, the processing unit 10 controls the second exhaust valve 23 on the second airbag 22 to open, allowing the second airbag 22 to deflate and return to its deflated state. Then, the processing unit 10 controls the first exhaust valve 9 to open, depressurizing the first airbag 6 and restoring it to its original state. Afterward, the processing unit 10 controls the electric push rod 4 to retract upward at a speed of 8 mm / s, resetting the mounting platform 5. The sliding tube 17 of the marking assembly and the absorbent cotton core 18 reset under gravity. Finally, the visual inspection camera 19 photographs and identifies the tested injection molded part, recognizing the breakage location 26 and the color of the markings 21 made by the marking assembly around the breakage location 26. After the visual inspection camera 19 transmits the image signal to the processing unit 10, the processing unit 10 reads and records the data of the pressure sensor 7 corresponding to the identified color, and finally displays it on the display unit 11 so that the test personnel can understand the test results.

[0055] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. An injection molded part strength tester characterized by, The utility model provides a kind of test platform for detecting the damage of detected piece, including rack, which is provided with test platform for placing detected piece, test platform is provided with gantry, electric push rod is vertically arranged downwards on gantry, and the output end of electric push rod is fixedly installed with mounting platform, first air bag is arranged below mounting platform, a plurality of pressure sensors are fixedly installed on the side of first air bag towards test platform, gas supply assembly for providing pressure gas for first air bag is fixedly installed on the top of gantry, first air bag is also provided with first exhaust valve for discharging gas inside first air bag, automatic control system is also arranged on the rack, and automatic control system includes processing unit and display unit, gas supply assembly, electric push rod, pressure sensor, first exhaust valve, display unit are electrically connected with processing unit, display unit is used to display the pressure value detected by each pressure sensor, a plurality of marking assemblies are also provided on the side of first air bag towards test platform corresponding to pressure sensor, marking assembly includes liquid storage ring fixedly installed on first air bag, and pressure sensor is located in the inner ring of corresponding liquid storage ring, a plurality of communication pipes are fixedly installed in the inside of liquid storage ring, the plurality of communication pipes are circumferentially distributed on liquid storage ring, one end of communication pipe towards test platform is sealingly connected with liquid storage ring, one end of communication pipe towards electric push rod is located on the upper side in the inside of liquid storage ring, communication pipe communicates the inside of liquid storage ring with the outside of liquid storage ring, the inside of liquid storage ring is stored with marking liquid, and the color of marking liquid stored in each liquid storage ring is different, and the liquid level of marking liquid in each liquid storage ring is not higher than the end face of pipe end of communication pipe located in the inside of liquid storage ring, sliding pipe is slidably installed in the inside of communication pipe, water-absorbing cotton core is arranged in the inside of sliding pipe, one end of water-absorbing cotton core located in liquid storage ring is soaked in marking liquid, one end of water-absorbing cotton core towards test platform protrudes from sliding pipe end face, and the lowest point of water-absorbing cotton core is lower than the lowest point of pressure sensor.

2. A strength tester for injection molded parts as defined in claim 1, characterized in that The mounting platform is made of metal material, four side plates made of metal material are fixedly installed on the bottom of the mounting platform, the four side plates enclose a rectangular guide space, the first air bag is located inside the guide space, and the first air bag is completely accommodated inside the guide space before being inflated.

3. A strength tester for injection molded parts as defined in claim 1, wherein The gantry is provided with a visual detection camera, the visual detection camera is electrically connected with the processing unit, and the visual detection camera is used to identify the damage position on the detected piece and identify the color at the damage position.

4. A strength tester for injection molded parts as defined in claim 3, wherein A rubber sheet is fixedly installed on the end face of one end of the pressure sensor towards the test platform, and the rubber sheet is used to increase the friction between the pressure sensor and the tested piece.

5. A strength tester for injection molded parts as defined in claim 1, wherein, The thickness of the side of the first air bag towards the test platform is 1cm-1.5cm, and the thickness of the side wall of the first air bag is 1 / 3 of the thickness of the side of the first air bag towards the test platform.

6. A strength tester for injection molded parts as defined in claim 2, wherein, The guide space is internally provided with a ring-shaped second air bag, the second air bag is communicated with a gas supply assembly, the second air bag is fixedly installed on the lower side of the four side plates, a second exhaust valve is arranged on the second air bag, the second exhaust valve is electrically connected with a processing unit, when the second air bag is inflated, the second air bag expands horizontally towards the center of the guide space.

7. A strength tester for injection molded parts as defined in claim 1, wherein, A wear-resistant layer is arranged on the side of the first air bag facing the test platform.

8. A strength tester for injection molded parts as defined in claim 2, wherein, A sound pickup unit is arranged in the guide space, the sound pickup unit is fixedly installed on one of the side plates, the sound pickup unit is electrically connected with the processing unit, and the sound pickup unit is used for identifying the sound of the broken detected piece.

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