Hydraulic mechanical component strength testing apparatus and testing method

Abstract

A hydraulic mechanical component strength testing apparatus and a testing method, relating to the technical field of mechanical component strength testing, for use in performing strength testing on mechanical components with different temperatures. The testing apparatus comprises a frame and a clamping assembly; the clamping assembly comprises two clamping plates and a clamping drive mechanism; a vertically-arranged hydraulic rod is arranged at the top of the frame; a placement platform fixedly connected to the bottom of the frame is arranged below the hydraulic rod; the two clamping plates are located above the placement platform; a placement seat for supporting a mechanical component is arranged between the two clamping plates; a hydraulic sensor for measuring the pressure borne by the placement seat is arranged between the placement seat and the placement platform; the placement platform is further provided with a display in signal connection with the hydraulic sensor; and the clamping plates are each provided with a heating assembly used for heating the mechanical component. The present invention can perform strength testing on mechanical components with different temperatures.

Description

Hydraulic mechanical component strength testing device and testing method Technical Field

[0001] The present invention relates to the technical field of mechanical component strength testing, and in particular to a hydraulic mechanical component strength testing device and testing method. Background Art

[0002] In order to better understand the performance of mechanical components, they need to be strength tested after production. A common test method is hydraulic testing, which uses hydraulic equipment to drop and impact the mechanical component. The degree of damage and deformation of the mechanical component is used to determine the compressive strength of the mechanical component.

[0003] Publication number CN219064863U describes a mechanical strength testing device. When in use, a mechanical part is placed between semicircular blocks one and two. A threaded rod, embedded in a fixed block, is then rotated, causing semicircular block one to move forward. Simultaneously, a damper stabilizes the rod as it moves forward, preventing semicircular block one from swaying and causing instability. The mechanical part is then clamped between the threaded rod and semicircular block two as semicircular block one moves. The strength of the part is then tested using a tester. The device can also accommodate testing of parts of varying sizes, expanding its scope of application.

[0004] Another example is a hydraulic mechanical component strength testing device with publication number CN204679258U. The device features a base with guide rods, upper and lower chucks between the guide rods, a mounting plate on the guide rods, a cylinder above the cylinder, a plunger with a push rod, and a movable platform on the guide rods. The base also features a main motor connected to an oil pump, which is connected to an oil tank. An oil inlet pipe is provided between the oil pump and the cylinder, which is connected to an oil outlet pipe. The oil outlet pipe is connected to a force-measuring plunger, which is equipped with a force-measuring pull rod, which is connected to a lever, which is connected to a pendulum. The pendulum is equipped with a roller, the outer wall of which is wrapped with recording paper, and the pendulum is equipped with a force-measuring gear rod. A gear is provided above the force-measuring gear rod, and the force-measuring gear rod is equipped with a recording pen. This device uses hydraulic principles as a power source to test the strength of long, rectangular components used in the oil field, and provides accurate test results.

[0005] The above-mentioned testing devices still have some deficiencies during use. For example, they cannot perform strength tests on mechanical components at different temperatures, and thus cannot compare the strengths of mechanical components at different temperatures. Technical issues

[0006] The purpose of the present invention is to provide a hydraulic mechanical component strength testing device and testing method, which is used to solve the problem that existing mechanical component strength testing devices cannot perform strength tests on mechanical components at different temperatures by heating the mechanical components. Technical Solutions

[0007] To achieve the above-mentioned objectives, the present invention provides the following technical solutions: A hydraulic mechanical component strength testing device, comprising a frame and a clamping assembly, the clamping assembly comprising two clamping plates and a clamping drive mechanism, the clamping drive mechanism driving the two clamping plates to move closer to or away from each other, characterized in that a vertically arranged hydraulic rod is provided at the top of the frame, a placement platform fixedly connected to the bottom of the frame is provided below the hydraulic rod, the two clamping plates are symmetrically arranged and located above the placement platform, and the clamping plates have limit blocks for contacting the mechanical component to be tested; a placement seat is provided between the two clamping plates and located at the top of the placement platform for supporting the mechanical component, a hydraulic sensor is provided between the placement seat and the placement platform for detecting the pressure exerted on the placement seat; the placement platform also has a display connected to the hydraulic sensor signal, the display is used to display the pressure detected by the hydraulic sensor; the clamping plate has a heating assembly for heating the mechanical component, and the frame has an observation assembly for observing the downward movement distance of the hydraulic rod; the hydraulic rod moves downward to squeeze the mechanical component placed on the placement seat, at which time the hydraulic sensor transmits the pressure exerted on the mechanical component to the display for display, and the downward movement distance of the hydraulic rod is observed by the observation assembly.

[0008] Furthermore, the frame includes a top plate and a base arranged above and below, and the top plate and the base are fixedly connected together via side baffles.

[0009] Furthermore, the clamping drive mechanism includes a screw rotatably installed in the placement table and a turntable fixed at the end of the screw and located outside the placement table. Two nuts with opposite moving directions are installed on the screw. The two clamps correspond one-to-one to the two nuts and are fixedly connected by a connecting plate.

[0010] Furthermore, the heating assembly includes an electric heating tube and fins, the clamping plate is a circular arc-shaped hollow structure, the electric heating tube is located in the internal cavity of the clamping plate, and the fins are located on the inner wall of the clamping plate.

[0011] Furthermore, the fins are evenly arranged along the arc direction of the inner side wall of the splint, and the limit block is fixedly connected to the inner side wall of the splint via a fixing rod.

[0012] Furthermore, the observation assembly includes a first set of rods and a second set of rods, the first set of rods is vertically arranged on the top of the base, the second set of rods is slidably arranged inside the first set of rods, a return spring is provided between the bottom of the second set of rods and the bottom of the first set of rods, the outer wall of the second set of rods has scale lines, and the second set of rods moves synchronously with the piston rod of the hydraulic rod.

[0013] Furthermore, it also includes a steel wire rope, a rear baffle is fixed on the top of the base, the steel wire rope is wound into an inverted "U" shape on the rear baffle through a pulley, one end of the steel wire rope is fixedly connected to the piston rod of the hydraulic rod, and the other end of the steel wire rope is fixedly connected to the top of the second set of rods.

[0014] Furthermore, a damping member is provided between the turntable and the placement table.

[0015] Furthermore, the damping member includes a retaining ring and a damping spring. The retaining ring is located between the turntable and the side wall of the placement table and is loosely sleeved on the outside of the screw. The retaining ring is a rubber member. One end of the damping spring is fixedly connected to the side wall of the placement table, and the other end of the damping spring is fixedly connected to the retaining ring.

[0016] The present invention also provides a testing method for a hydraulic mechanical component strength testing device, comprising the following steps:

[0017] S1. Place the mechanical component to be tested on the placement seat, and use the clamping drive mechanism to drive the two clamping plates closer together until the two limit blocks cooperate to clamp the mechanical component;

[0018] S2. activating the hydraulic rod so that the piston rod of the hydraulic rod moves downward, directly contacting the piston rod with the mechanical component and applying pressure to the mechanical component, detecting the pressure on the mechanical component by the hydraulic sensor, and observing the downward movement distance of the piston rod of the hydraulic rod by the observation assembly;

[0019] S3, driving the hydraulic rod to reset, driving the two clamping plates to separate from the mechanical component through the clamping drive mechanism, and then adjusting the position of the mechanical component and clamping the mechanical component again through the clamping plates;

[0020] S4, starting the heating component to heat the mechanical component;

[0021] S5, execute step S2 again;

[0022] S6. Compare the pressure and distance data measured in step S2 and step S5. Beneficial effects

[0023] The beneficial effects of the present invention are: (1) by arranging a heating component on the clamping plate to heat the mechanical component to be tested, the strength of the mechanical component is tested before and after heating, and the strength of the mechanical component at different temperatures is compared; (2) by setting the observation component, the deformation of the mechanical component at different temperatures can be intuitively observed, and the strength of the mechanical component can be understood from the perspective of deformation. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] FIG1 is one of the three-dimensional diagrams of the present invention;

[0025] FIG2 is a second three-dimensional diagram of the present invention;

[0026] FIG3 is a three-dimensional assembly diagram of the placement table, base, side panels, rear panel, display, and clamping assembly of the present invention;

[0027] FIG4 is a schematic diagram of the internal structure of the placement table of the present invention;

[0028] FIG5 is a three-dimensional assembly diagram of the splint and the nut of the present invention;

[0029] FIG6 is a three-dimensional cross-sectional view of the first set of rods and the second set of rods of the present invention;

[0030] FIG7 is a partial enlarged view of point A in FIG6;

[0031] FIG8 is a three-dimensional assembly diagram of the lead screw, retaining ring and turntable of the present invention;

[0032] FIG9 is a three-dimensional assembly diagram of the base, display and placement table of the present invention;

[0033] FIG10 is a three-dimensional assembly diagram of the clamping plate and the electric heating tube of the present invention;

[0034] FIG11 is a three-dimensional diagram of the second set of rods of the present invention;

[0035] FIG12 is a bottom view of a protective cover provided at the bottom of the top plate;

[0036] In the figure: 1 frame, 11 base, 12 side baffle, 13 top plate, 14 rear baffle, 2 placement table, 21 long slot, 22 placement seat, 23 screw, 24 guide rail, 25 support seat, 26 turntable, 27 snap ring, 28 damping spring, 3 splint, 31 nut, 32 connecting plate, 33 first slider, 34 limit block, 35 fixing rod, 36 fin, 37 electric heating tube, 4 display, 5 first set of rods, 51 second set of rods, 52 second slider, 53 return spring, 54 slide, 55 scale line, 6 wire rope, 7 pulley, 8 hydraulic rod, 81 cross bar, 9 shield, 91 protective cylinder, 92 ear plate. Modes for Carrying Out the Invention

[0037] As shown in FIG1 to FIG12, the present invention includes a frame 1, a placement table 2, a clamping assembly, a hydraulic rod 8, a display 4 and an observation assembly. The present invention will be described in detail below with reference to the accompanying drawings.

[0038] As shown in Figures 1 and 2, a hydraulic mechanical component strength testing device includes a frame 1 and a clamping assembly. The frame 1 includes a top plate 13 and a base 11 arranged upper and lower. The top plate 13 and the base 11 are fixedly connected together by side baffles 12. The top of the frame 1, that is, the top plate 13, is provided with a vertically arranged hydraulic rod 8. Below the hydraulic rod 8, there is a placement table 2 fixedly connected to the base 11 at the bottom of the frame 1. The clamping assembly includes two symmetrically arranged clamps 3 and a clamping drive mechanism. The clamping drive mechanism is arranged in the placement table 2 and is used to drive the two clamps 3 to move closer to or away from each other. The clamps 3 are of an arc-shaped structure. The two clamps 3 are located above the placement table 2. The inner side of the clamps 3 is fixedly connected to a limit block 34 by a fixing rod 35. The limit block 34 is used to contact the mechanical component to be tested. The limit blocks 34 on the two clamps 3 cooperate to clamp the mechanical component. As shown in Figures 3 and 4, the clamping drive mechanism includes a lead screw 23 rotatably mounted within the placement platform 2 and a turntable 26 fixed to the end of the lead screw 23 and located outside the placement platform 2. The lead screw 23 is fitted with two screw nuts 31 that move in opposite directions. By providing two sections of external threads with opposite rotation directions on the lead screw 23 and fitting the two screw nuts 31 to the two external threads, the two screw nuts 31 can move in opposite directions. As shown in Figure 5, the two clamping plates 3 correspond to the two screw nuts 31 in a one-to-one manner and are fixedly connected by a connecting plate 32. Thus, the clamping plates 3, connecting plate 32, and screw nuts 31 are arranged sequentially from top to bottom and fixedly connected to form a single unit. When the turntable 26 of the clamping drive mechanism is rotated, the lead screw 23 rotates accordingly, causing the two screw nuts 31 to move axially along the lead screw 23 in opposite directions, thereby moving the two clamping plates 3 closer to or further away from each other. When the two clamping plates 3 approach each other, causing the stop block 34 to contact the mechanical component, clamping the mechanical component. When the two clamping plates 3 move away from each other so that the limiting block 34 is separated from the mechanical component, the clamping effect of the two clamping plates 3 on the mechanical component is released.

[0039] To prevent the lead screw 23 from rotating on its own, a damping member is provided between the turntable 26 and the placement table 2. As shown in FIG8 , the damping member includes a snap ring 27 and a damping spring 28. As shown in FIG3 , the snap ring 27 is located between the turntable 26 and the side wall of the placement table 2 and is loosely sleeved on the outside of the lead screw 23. The snap ring 27 is a rubber member. One end of the damping spring 28 is fixedly connected to the side wall of the placement table 2, and the other end of the damping spring 28 is fixedly connected to the snap ring 27. There are multiple damping springs 28 evenly arranged along the circumference. Under the action of the damping spring 28, the snap ring 27 is in close contact with the turntable 26, thereby increasing the friction force when the turntable 26 is rotated, thereby achieving a damping effect. To assemble the lead screw 23, as shown in FIG8 , a support seat 25 is provided at the end of the lead screw 23, and the support seat 25 is rotatably connected to the lead screw 23.

[0040] As shown in Figure 3, a support seat 22 is located on top of the platform 2 between the two clamping plates 3 to support the mechanical components. A hydraulic pressure sensor is located between the support seat 22 and the platform 2 to detect the pressure on the support seat 22. The platform 2 also has a display 4 connected to the hydraulic pressure sensor signal to display the pressure detected by the hydraulic pressure sensor.

[0041] To avoid the connection plate 32, as shown in Figure 9, a long slot 21 is provided on the top of the placement table 2, and the connection plate 32 extends through the long slot 21. The long slots 21 are symmetrically arranged, and the placement seat 22 is located between the two long slots 21. To guide the movement of the nut 31, as shown in Figure 4, a guide rail 24 is provided on the inside of the placement table 2. The guide rail 24 has two guide rails, and the nut 31 is located between the two guide rails 24. As shown in Figure 5, a "T"-shaped first slider 33 is provided on the side wall of the nut 31. The nut 31 is slidably connected to the guide rail 24 via the first slider 33.

[0042] As shown in Figure 10, the clamping plate 3 is equipped with a heating assembly for heating the mechanical components. The heating assembly heats the mechanical components. The heating assembly includes an electric heating tube 37 and fins 36. The clamping plate 3 is a hollow structure. The electric heating tube 37 is located within the internal cavity of the clamping plate 3, and the fins 36 are located on the inner wall of the clamping plate 3. The fins 36 are evenly arranged along the arc direction of the inner wall of the clamping plate 3. When the electric heating tube 37 is energized, heat is transferred to the fins 36 through the clamping plate 3. The fins 36 then transfer heat to the mechanical components through the air, thereby heating the mechanical components.

[0043] As shown in FIG1 , the frame 1 also has an observation assembly for observing the downward movement distance of the hydraulic rod 8. As shown in FIG1 and FIG6 , the observation assembly includes a first set of rods 5 and a second set of rods 51. The first set of rods 5 is vertically arranged on the top of the base 11, and the second set of rods 51 is slidably arranged inside the first set of rods 5. A return spring 53 is provided between the bottom of the second set of rods 51 and the bottom of the first set of rods 5. As shown in FIG11 , the outer wall of the second set of rods 51 has a scale line 55. The second set of rods 51 moves synchronously with the piston rod of the hydraulic rod 8. Specifically, it also includes a wire rope 6. A rear baffle 14 located on the rear side is fixed to the top of the base 11. The wire rope 6 is wound on the rear baffle 14 into an inverted "U" shape through a pulley 7. One end of the wire rope 6 is fixedly connected to the piston rod of the hydraulic rod 8, and the other end of the wire rope 6 is fixedly connected to the top of the second set of rods 51. To facilitate assembly, a crossbar 81 is fixed to the piston rod of the hydraulic rod 8. This crossbar 81 is fixedly connected to one end of the wire rope 6, thereby securing the connection between the wire rope 6 and the hydraulic rod 8. As the hydraulic rod 8 moves downward, it compresses the mechanical components placed on the support seat 22. The hydraulic sensor transmits the pressure exerted on the mechanical components to the display 4, and the observation assembly can be used to measure the distance the hydraulic rod 8 moves downward. Specifically, as the piston rod of the hydraulic rod 8 moves downward, the crossbar 81 pulls one end of the wire rope 6 downward, while the other end of the wire rope 6 pulls the second set of rods 51 upward. By observing the scale lines 55 exposed on the second set of rods 51, the distance the second set of rods 51 moves upward, and thus the distance the hydraulic rod 8 moves downward, can be determined.

[0044] In order to achieve a sliding connection between the second set of rods 51 and the first set of rods 5, as shown in Figure 7, a sliding groove 54 is provided on the side wall of the first set of rods 5, and a "T"-shaped second slider 52 is provided on the outer wall of the second set of rods 51. The second slider 52 is slidingly connected to the sliding groove 54.

[0045] To shorten the heating time of the mechanical components and ensure effective heating, as shown in Figure 12, a circular shield 9 is installed below the top plate 13. The sidewalls of the shield 9 are equipped with lugs 92. Two protective cylinders 91 are fixed to the bottom of the top plate 13. The cylinder barrels of the protective cylinders 91 are fixedly connected to the bottom of the top plate 13, and the piston rods of the protective cylinders 91 are fixedly connected to the lugs 92. When the protective cylinders 91 are in operation, they drive the shield 9 up and down. When the electric heating tubes 37 in the clamping plates 3 are energized, they heat the mechanical components. At this point, the action of the protective cylinders 91 causes the shield 9 to move down to its lowest point. At this point, the shield 9 contacts the top of the base 11 and covers the outside of the two clamping plates 3, thereby providing insulation during heating of the mechanical components, improving heating efficiency and shortening heating time. To facilitate monitoring of the heating temperature of the mechanical components, temperature sensors are installed on the sidewalls of the stop blocks 34. The temperature of the mechanical components is detected by contact between the temperature sensors and the mechanical components. The temperature sensor is connected to the display 4 via a Bluetooth signal, and the display 4 displays the temperature value detected by the temperature sensor.

[0046] The working principle of the testing device of the present invention is described below: When in use, the mechanical component to be tested is placed on the placement seat 22, and the two clamps 3 are driven close together by the clamping drive mechanism so that the clamps 3 come into contact with the mechanical component, thereby achieving clamping of the mechanical component. Pressure is applied to the mechanical component by the hydraulic rod 8, and the pressure on the placement seat 22 or the mechanical component is detected by the hydraulic sensor and displayed on the display 4. The distance the second set of rods 51 moves upward relative to the first set of rods 5 is observed by the observation component to understand the distance the hydraulic rod 8 moves downward. The fins 36 are heated by the electric heating tube 37 of the heating component, and then the mechanical component is heated. After heating, the mechanical component is subjected to a strength test again. By performing strength tests on the mechanical component before and after heating, the effect of temperature on the strength of the mechanical component can be understood.

[0047] The following describes a testing method for a hydraulic mechanical component strength testing device of the present invention, comprising the following steps:

[0048] S1. Place the mechanical component to be tested on the placement seat 22, and drive the two clamping plates 3 closer together through the clamping drive mechanism until the two limit blocks 34 cooperate to clamp the mechanical component;

[0049] S2. Start the hydraulic rod 8 so that the piston rod of the hydraulic rod 8 moves downward, directly contacting the mechanical component and applying pressure to the mechanical component. The pressure on the mechanical component is detected by the hydraulic sensor, and the downward movement distance of the piston rod of the hydraulic rod 8 is observed by the observation assembly. Mechanical components of different materials are placed on the placement seat 22 to perform strength testing on mechanical components of different materials.

[0050] S3, driving the hydraulic rod 8 to reset, driving the two clamping plates 3 to separate from the mechanical component through the clamping drive mechanism, and then adjusting the position of the mechanical component and clamping the mechanical component again through the clamping plates 3;

[0051] S4, starting the heating component to heat the mechanical parts through the heating component;

[0052] S5. Execute step S2 again to perform strength testing on mechanical components at different temperatures.

[0053] S6. Compare the pressure and distance data measured in step S2 and step S5.

[0054] The present invention heats the mechanical component to be tested by arranging a heating component on the clamping plate, and performs strength tests on the mechanical component before and after heating, thereby comparing the strengths of the mechanical component at different temperatures; through the arrangement of the observation component, the deformation amount of the mechanical component at different temperatures can be intuitively observed, thereby understanding the strength of the mechanical component from the perspective of deformation.

Claims

1. A hydraulic mechanical component strength testing device, comprising a frame and a clamping assembly, wherein the clamping assembly comprises two clamping plates and a clamping drive mechanism, wherein the clamping drive mechanism drives the two clamping plates to move closer to or farther from each other, characterized in that: The top of the frame is provided with a vertically arranged hydraulic rod, and the bottom of the hydraulic rod is provided with a placing platform fixedly connected to the bottom of the frame, the two clamps are symmetrically arranged and located above the placing platform, and the clamps are provided with limit blocks for contacting the mechanical parts to be tested; between the two clamps is provided with a placing seat located at the top of the placing platform for supporting the mechanical parts, and between the placing seat and the placing platform is provided with a hydraulic sensor for detecting the pressure exerted on the placing seat; the placing platform also has a display connected to the hydraulic sensor signal, and the display is used to display the pressure detected by the hydraulic sensor; the clamp is provided with a heating component for heating the mechanical parts, and the frame is provided with an observation component for observing the downward movement distance of the hydraulic rod; the hydraulic rod moves downward to squeeze the mechanical parts placed on the placing seat, and at this time the hydraulic sensor transmits the pressure exerted on the mechanical parts to the display for display, and the downward movement distance of the hydraulic rod is observed through the observation component.

2. A hydraulic mechanical component strength testing device according to claim 1, characterized in that: The frame includes a top plate and a base arranged up and down, and the top plate and the base are fixedly connected together through side baffles.

3. A hydraulic mechanical component strength testing device according to claim 1, characterized in that: The clamping drive mechanism includes a screw rotatably installed in the placement table and a turntable fixed at the end of the screw and located outside the placement table. Two nuts with opposite moving directions are installed on the screw. The two clamps correspond to the two nuts one by one and are fixedly connected by a connecting plate.

4. A hydraulic mechanical component strength testing device according to claim 1, characterized in that: The heating assembly includes an electric heating tube and fins. The clamping plate is a circular arc-shaped hollow structure. The electric heating tube is located in the internal cavity of the clamping plate, and the fins are located on the inner wall of the clamping plate.

5. A hydraulic mechanical component strength testing device according to claim 4, characterized in that: The fins are evenly arranged along the arc direction of the inner side wall of the clamping plate, and the limit block is fixedly connected to the inner side wall of the clamping plate through a fixing rod.

6. A hydraulic mechanical component strength testing device according to claim 1, characterized in that: The observation assembly includes a first set of rods and a second set of rods. The first set of rods is vertically arranged on the top of the base, and the second set of rods is slidably arranged inside the first set of rods. A return spring is provided between the bottom of the second set of rods and the bottom of the first set of rods. The outer wall of the second set of rods has scale lines, and the second set of rods moves synchronously with the piston rod of the hydraulic rod.

7. A hydraulic mechanical component strength testing device according to claim 6, characterized in that: It also includes a steel wire rope, a rear baffle is fixed on the top of the base, the steel wire rope is wound into an inverted "U" shape on the rear baffle through a pulley, one end of the steel wire rope is fixedly connected to the piston rod of the hydraulic rod, and the other end of the steel wire rope is fixedly connected to the top of the second set of rods.

8. The hydraulic mechanical component strength testing device according to claim 3, characterized in that: A damping member is provided between the turntable and the placement table.

9. A hydraulic mechanical component strength testing device according to claim 8, characterized in that: The damping member includes a retaining ring and a damping spring. The retaining ring is located between the turntable and the side wall of the placement table and is loosely sleeved on the outside of the lead screw. The retaining ring is a rubber member. One end of the damping spring is fixedly connected to the side wall of the placement table, and the other end of the damping spring is fixedly connected to the retaining ring.

10. A testing method for a hydraulic mechanical component strength testing device according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1. Place the mechanical component to be tested on the placement seat, and use the clamping drive mechanism to drive the two clamping plates closer together until the two limit blocks cooperate to clamp the mechanical component; S2. activating the hydraulic rod so that the piston rod of the hydraulic rod moves downward, directly contacting the piston rod with the mechanical component and applying pressure to the mechanical component, detecting the pressure on the mechanical component by the hydraulic sensor, and observing the downward movement distance of the piston rod of the hydraulic rod by the observation assembly; S3, driving the hydraulic rod to reset, driving the two clamping plates to separate from the mechanical component through the clamping drive mechanism, and then adjusting the position of the mechanical component and clamping the mechanical component again through the clamping plates; S4, starting the heating component to heat the mechanical component through the heating component; S5, execute step S2 again; S6. Compare the pressure and distance data measured in step S2 and step S5.

Images