Ammonia mixing test equipment and test method for automobile exhaust system

Abstract

The present invention relates to the field of vehicle testing, specifically to an ammonia mixing test device and test method for an automobile exhaust system. It is used to perform an ammonia mixing test on a catalyst. The catalyst has an air inlet and an exhaust port. The ammonia mixing test device includes an air intake device, a gas delivery device, a gas detection mechanism, and a base. The air intake device includes a mounting frame, a mounting assembly arranged on the mounting frame, a plurality of air intake pipes evenly distributed around the mounting assembly, and an adjustment assembly arranged on the mounting frame and adjusting the spacing between the plurality of air intake pipes. The front end of the air intake pipe has an air intake head. The gas delivery device includes a vent disk with a plurality of air inlet channels on the periphery, a connecting disk with an air channel, a first motor for driving the connecting disk to rotate, a connecting pipe connected to the air inlet channel with a radial sliding seal, and an air inlet pipe connected to the air channel outlet with a rotating seal. A support seat and a transverse movement mechanism are provided on the base. The present invention can perform multi-point ammonia mixing detection on the inside of the catalyst to obtain more detailed ammonia mixing distribution data.

Description

Technical Field

[0001] The present invention relates to the field of vehicle testing, and in particular to an ammonia mixing testing device and a testing method for an automobile exhaust system. Background Art

[0002] In an SCR (Selective Catalytic Reduction) catalyst, the vehicle's urea injection system injects a urea solution into the exhaust pipe. The urea solution undergoes thermal decomposition and hydrolysis in the exhaust to form ammonia, which reacts with NOx (nitrogen oxides) in the exhaust gas to produce harmless nitrogen and water, thereby reducing NOx levels. Ammonia distribution (ammonia mixing) is a key evaluation parameter in SCR catalysts. Uneven ammonia mixing can severely impact product performance.

[0003] Chinese Patent Publication No. CN114235435B discloses an ammonia mixing tester for automobile exhaust systems, comprising a flexible base, an air extraction pipe, a synchronous connecting rod, a motor base, a servo motor, a guide optical axis, and a gas detection mechanism. The same set of air extraction pipes for the inlet and outlet of the catalyst under test enables simultaneous air extraction during a single exhaust operation. The catalyst under test remains structurally intact except for the installation of the air extraction mechanism, resulting in excellent measurement results, high accuracy, and significantly improved measurement efficiency.

[0004] However, the above solution has the following shortcomings: it can only take gas samples for testing at the catalyst inlet and outlet, but cannot take gas samples for testing at different points inside the catalyst, making it difficult to obtain more detailed ammonia mixture distribution test data. Summary of the Invention

[0005] The purpose of the present invention is to address the problems existing in the background technology and propose an automobile exhaust system ammonia mixing test device and test method that can perform multi-point ammonia mixing detection on the inside of the catalyst to obtain more detailed ammonia mixing distribution data.

[0006] On the one hand, the present invention provides an ammonia mixing test device for an automobile exhaust system, which is used to perform an ammonia mixing test on a catalyst. The catalyst has an air inlet and an exhaust port. The ammonia mixing test device includes an air intake device, a gas delivery device, a gas detection mechanism and a base; the air intake device includes a mounting frame, a mounting assembly arranged on the mounting frame, a plurality of air intake pipes evenly distributed around the mounting assembly, and an adjustment assembly arranged on the mounting frame and adjusting the spacing between the plurality of air intake pipes, and an air intake head is provided at the front end of the air intake pipe; the air delivery device includes a vent plate with a plurality of air inlet channels evenly distributed around a central axis and arranged radially on the outer periphery, a rotary seal arranged on the vent plate and A connecting disk with an air passage, a first motor for driving the connecting disk to rotate, a connecting pipe that is radially slidingly sealed and connected to the air duct, and an air duct that is rotatably sealed and connected to the air duct outlet, the air disk and the first motor are both arranged on a mounting frame, the air duct outlet is located in the middle of the connecting disk, the air duct inlet is located on the circumferential surface of the connecting disk, the connecting pipe is connected to the air intake pipe, and when the connecting disk rotates, the air duct connects the air intake pipe with one of the multiple connecting pipes; the gas detection mechanism is connected to the air intake pipe; a support seat for supporting the catalyst is provided on the base, and a transverse movement mechanism that drives the mounting frame to move horizontally to adjust the distance the air intake pipe extends into the interior of the catalyst.

[0007] Preferably, the mounting assembly includes a connecting frame arranged on the mounting frame, a plurality of slide rails evenly distributed in a ring shape on the connecting frame, a mounting platform arranged on the slide rails, and a slider slidably arranged on the slide rails, and the air extraction pipe is arranged on the slider.

[0008] Preferably, a cross bar is provided at the front of the mounting platform, and a guide platform is provided at the front end of the cross bar. The guide platform is located between multiple air extraction pipes. The guide platform has a conical guide surface, the top of the conical guide surface is located on the side away from the cross bar, and the conical guide surface is concave inward.

[0009] Preferably, the adjustment component includes a second motor arranged on the mounting frame, a first screw rod rotatably arranged on the mounting frame and connected to the output end of the second motor, a movable seat threadedly connected to the first screw rod, and a plurality of connecting components evenly distributed around the movable seat, the connecting component includes a rotating sleeve arranged on the air extraction pipe and a connecting rod with both ends rotatably connected to the rotating sleeve and the movable seat respectively.

[0010] Preferably, the air intake pipe includes a first straight pipe portion, an inclined pipe portion and a second straight pipe portion that are connected as a whole, the first straight pipe portion and the second straight pipe portion are parallel, and the air inlet head is located at the outer end of the first straight pipe portion; the connecting pipe includes a right-angle pipe portion, a third straight pipe portion, a fourth straight pipe portion and a fifth straight pipe portion that are connected as a whole, the second straight pipe portion is connected to the right-angle pipe portion in a rotating seal, and the fifth straight pipe portion is connected to the air inlet channel of the ventilation disk in a sliding seal.

[0011] Preferably, the second straight tube portion of the air extraction pipe is rotatably arranged on the slider and the rotating sleeve, a first gear is arranged on the second straight tube portion, a limiting assembly for limiting and releasing the limit of the first gear is arranged on the mounting assembly, a third motor is arranged on the mounting platform, and the third motor drives the second gear. When the multiple air extraction pipes are retracted to the extreme position, the first gear is engaged with the second gear, and the limiting assembly releases the limit on the first gear.

[0012] Preferably, the limiting assembly includes a stop platform arranged on the mounting platform, a fixed plate arranged on the slider, a sliding column slidingly arranged on the fixed plate, a movable frame and a connecting platform respectively connected to both ends of the sliding column, a rack arranged on the movable frame and facing the first gear, and a spring mounted on the sliding column and connected to the fixed plate and the connecting platform at both ends respectively, and the connecting platform faces the stop platform.

[0013] Preferably, the transverse movement mechanism includes a second screw rod horizontally rotatably arranged on the base, a guide rod parallel to the second screw rod and arranged on the base, a fourth motor arranged on the base and driven by the second screw rod, a support frame arranged at the bottom of the mounting frame, and a movable platform arranged at the bottom of the support frame, the movable platform being slidably arranged on the guide rod and being threadedly connected to the second screw rod.

[0014] Preferably, the air duct is connected to an exhaust pipe, a control valve is provided on the exhaust pipe, the exhaust pipe is connected to an exhaust pump, multiple ventilation pipes are evenly connected to the periphery of the ventilation plate, the multiple ventilation pipes are spaced apart from the multiple air ducts, and a filter is provided at the ventilation pipe.

[0015] In another aspect, the present invention provides a method for testing ammonia mixing in an automobile exhaust system, which is implemented using the above-mentioned automobile exhaust system ammonia mixing testing device. The method comprises the following steps:

[0016] S1. Place the catalyst to be tested on the support;

[0017] S2. Start the second motor, which drives the first screw to rotate. The multiple connecting components drive the multiple air extraction pipes to close until the first gear and the second gear are meshed. At this time, the rack is disengaged from the first gear.

[0018] S3. Start the third motor, which drives the second gear to rotate. The second gear drives the air intake pipes to rotate through the first gear, rotating the first straight pipe portions of the multiple air intake pipes inward to reduce the distance between the multiple air intake heads.

[0019] S4. The mounting frame is driven to move horizontally by the transverse movement mechanism, and the plurality of air intake heads are extended from the exhaust port of the catalyst into the interior of the catalyst until the air intake heads move to one side of the air intake port;

[0020] S5. The gas to be tested is continuously introduced into the air inlet of the catalyst, and the catalyst is activated simultaneously;

[0021] S6. The connecting disk is driven to rotate by the first motor, and the air passage connects the air bleed pipe to one of the multiple connecting pipes. Each time one of the multiple connecting pipes is connected, the air inlet head on the air extraction pipe connected to the corresponding connecting pipe introduces gas into the air extraction pipe. The air extraction pipe transmits the gas through the connecting pipe, the vent disk, the connecting disk, and the air bleed pipe to the gas detection mechanism. The gas detection mechanism sequentially detects ammonia mixing in the gas introduced by the multiple air inlet heads.

[0022] S7. Start the second motor, which intermittently drives the first screw to rotate in the opposite direction. The first gear disengages from the second gear, and the rack is locked on the first gear to limit its position. The gas pipe intermittently moves outward. During each intermittent period of stopping the outward movement, step S6 is performed. The gas detection mechanism sequentially performs ammonia mixing detection on the gas introduced by the multiple gas inlet heads.

[0023] S8. Re-engage the first gear and the second gear, start the third motor, adjust the distribution position of the gas inlet head at the front end of the gas intake pipe, and then repeat steps S6-S7. The gas detection mechanism sequentially performs ammonia mixing detection on the gas introduced by the multiple gas inlet heads;

[0024] S9. The mounting frame is intermittently driven to move away from the exhaust port of the catalyst by the transverse movement mechanism. Step S8 is performed in each intermittent period of stopping the transverse movement, thereby achieving the purpose of multi-point ammonia mixing detection inside the catalyst.

[0025] Compared with the prior art, the present invention has the following beneficial technical effects:

[0026] The present invention can perform ammonia mixing detection at multiple points inside the catalyst, thereby obtaining more detailed ammonia mixing distribution data. The inlet head distribution position can be adjusted, and the gas detection mechanism only detects ammonia mixing of the gas introduced by one inlet head at a time. Overall, the gas detection mechanism detects gas introduced at more points, obtaining more detailed ammonia mixing distribution data. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 Schematic diagram of the structure of an embodiment of the present invention;

[0028] Figure 2 A partial structural cross-sectional view of an embodiment of the present invention;

[0029] Figure 3 A cross-sectional view of the principle structure for adjusting the position of the air intake pipe;

[0030] Figure 4 for Figure 3 A magnified view of the structure at point A;

[0031] Figure 5 A schematic diagram of a structure for adjusting multiple gas extraction pipes to another distribution state;

[0032] Figure 6 Schematic diagram of the structure for clamping the catalyst.

[0033] Reference numerals: 100, catalyst; 1, base; 2, support base; 3, mounting frame; 4, connecting frame; 5, slide rail; 6, mounting platform; 7, slider; 8, air intake pipe; 81, air intake head; 9, connecting pipe; 10, ventilation plate; 11, connecting plate; 111, air duct; 12, air bleed pipe; 13, ventilation pipe; 14, first motor; 15, first gear; 16, fixing plate; 17, sliding column; 171, spring; 18, movable frame; 19. Rack; 20. Connecting platform; 21. Stop platform; 22. Rotating sleeve; 23. Connecting rod; 24. Moving seat; 25. Second motor; 26. First screw rod; 27. Second gear; 28. Third motor; 29. Cross bar; 30. Guide platform; 31. Support frame; 32. Moving platform; 33. Fourth motor; 34. Second screw rod; 35. Guide rod; 36. Fixed seat; 37. Threaded knob; 38. Sliding rod; 39. Clamp. DETAILED DESCRIPTION

[0034] Example 1, as Figures 1-6 As shown, this embodiment provides an ammonia mixing test device for an automobile exhaust system, which is used to perform an ammonia mixing test on a catalyst 100. The catalyst 100 has an air inlet and an exhaust port. The ammonia mixing test device includes a gas extraction device, a gas delivery device, a gas detection mechanism, and a base 1. The gas extraction device extends into the interior of the catalyst 100 and delivers gas through the gas delivery device to the gas detection mechanism for ammonia mixing detection.

[0035] like Figure 2-Figure 5 As shown, the gas extraction device includes a mounting frame 3, a mounting assembly arranged on the mounting frame 3, a plurality of gas extraction pipes 8 evenly distributed around the mounting assembly, and an adjustment assembly arranged on the mounting frame 3 and adjusting the spacing between the plurality of gas extraction pipes 8. The front end of the gas extraction pipe 8 is provided with an air inlet head 81. The air inlet head 81 faces the direction of the incoming gas, and the gas can be directly blown into the air inlet head 81, and then circulate along the gas extraction pipe 8, and finally circulate to the gas detection mechanism. By adjusting the spacing between the plurality of gas extraction pipes 8 through the adjustment assembly, the radial position of the plurality of gas extraction pipes 8 distributed circumferentially can be adjusted, so that the air inlet head 81 can extract gas at multiple points, thereby expanding the gas extraction range.

[0036] like Figure 3As shown, the air delivery device includes a vent disc 10 having a plurality of air ducts evenly distributed around a central axis and arranged radially on its outer periphery, a connecting disc 11 having an air duct 111 and being rotatably sealed on the vent disc 10, a first motor 14 for driving the connecting disc 11 to rotate, a connecting pipe 9 radially slidingly sealed to the air duct, and an air duct 12 rotatably sealed to the outlet of the air duct 111. When the first motor 14 drives the connecting disc 11 to rotate, the air duct 111 can be connected to air ducts in different directions, and the air duct 111 maintains communication with the air duct 12. The vent disc 10 and the first motor 14 are both mounted on the mounting frame 3. The outlet of the air duct 111 is located in the middle of the connecting disc 11. Rotation of the connecting disc 11 does not affect the connection with the air duct 12. The inlet of the air duct 111 is located on the circumferential surface of the connecting disc 11. When the inlet of the air duct 111 faces a particular air duct, it communicates with that air duct. The connecting tube 9 is connected to the air intake pipe 8. When the air intake pipe 8 moves, the connecting tube 9 slides in the air bleed channel, but remains connected and does not interfere with the movement of the air intake pipe 8. When the connecting disk 11 rotates, the air channel 111 connects the air bleed pipe 12 to one of the multiple connecting tubes 9. That is, the air channel 111 can only connect to one air bleed channel on the vent disk 10 at a time, and connects the connecting tube 9 to the air bleed pipe 12 through the air bleed channel and the air channel 111, realizing air supply to the gas detection mechanism.

[0037] The gas detection mechanism is connected to the air bleed pipe 12 and performs ammonia mixing detection on the gas delivered from the air intake head 81, the air intake pipe 8, the connecting pipe 9, the air bleed channel of the ventilation disk 10, the air channel 111 of the connecting disk 11 and the air bleed pipe 12.

[0038] like Figure 1 and Figure 5 As shown, the base 1 is equipped with a support base 2 for supporting the catalyst 100 and a transverse movement mechanism that drives the mounting frame 3 to move horizontally to adjust the distance that the gas intake pipe 8 extends into the interior of the catalyst 100. The transverse movement mechanism adjusts the horizontal position of the mounting frame 3 to adjust the insertion depth of the gas intake pipe 8, allowing the gas to be introduced at different positions using the gas inlet head 81.

[0039] like Figure 1 As shown, the transverse movement mechanism includes a second screw rod 34 horizontally rotatably mounted on the base 1, a guide rod 35 parallel to the second screw rod 34 and mounted on the base 1, a fourth motor 33 mounted on the base 1 and drivingly connected to the second screw rod 34, a support frame 31 mounted at the bottom of the mounting frame 3, and a movable platform 32 mounted at the bottom of the support frame 31. The movable platform 32 is slidably mounted on the guide rod 35 and threadedly connected to the second screw rod 34. The fourth motor 33 can drive the second screw rod 34 in forward and reverse rotation, which in turn drives the movable platform 32 to move. The guide rod 35 guides the movable platform 32, causing it to move horizontally. The movable platform 32 drives the mounting frame 3 to move horizontally via the support frame 31, resulting in a smooth movement process.

[0040] Furthermore, a structure that can improve the position stability of the catalyst 100 is added, such as Figure 1 and Figure 6 As shown, the top of the support base 2 has a supporting groove that matches the contour of the lower part of the catalyst 100. Two sets of clamping components are symmetrically arranged on the support base 2, which can be clamped from both sides of the catalyst 100 to ensure stability during the ammonia mixing test. Figure 6 As shown, the clamping assembly includes a fixed base 36 disposed at the outer end of the support base 2, a horizontally distributed threaded knob 37 threadedly connected to the fixed base 36, a slide rod 38 parallel to the threaded knob 37 and slidably disposed on the fixed base 36, and a clamping plate 39 connected to the end of the slide rod 38. The clamping plate 39 is rotatably connected to the end of the threaded knob 37. By rotating the threaded knob 37, the threaded knob 37 can be moved on the fixed base 36, thereby driving the clamping plate 39 to move. The slide rod 38 slides on the fixed base 36 to guide the movement of the clamping plate 39. The threaded connection between the threaded knob 37 and the fixed base 36 is self-locking, ensuring stability when the clamping plates 39 on both sides are clamped.

[0041] like Figure 2 and Figure 5 As shown, the mounting assembly includes a connecting frame 4 mounted on a mounting frame 3, a plurality of slide rails 5 evenly distributed in a circular pattern on the connecting frame 4, a mounting platform 6 mounted on the slide rails 5, and a slider 7 slidably mounted on the slide rails 5. An air extraction pipe 8 is mounted on the slider 7. The slider 7 is capable of sliding on the slide rails 5. The multiple sliders 7 can move synchronously toward the central mounting platform 6 or move synchronously away from each other, thereby driving the multiple air extraction pipes 8 to synchronously converge or disperse, thereby achieving the purpose of adjusting the spacing between the multiple air extraction pipes 8.

[0042] A crossbar 29 is located at the front of the mounting platform 6, and a guide platform 30 is located at the front end of the crossbar 29. This platform 30 is located between the multiple air intake pipes 8, shielding the rearward structure. The guide platform 30 has a conical guide surface, with its apex located away from the crossbar 29 and recessed inward. As gas exits the exhaust port of the catalyst 100, it is guided by the conical guide surface 30, directing the gas in a circumferential direction to prevent it from affecting the rearward structure.

[0043] like Figure 3 and Figure 4As shown, the adjustment assembly includes a second motor 25 mounted on the mounting frame 3, a first screw rod 26 rotatably mounted on the mounting frame 3 and connected to the output end of the second motor 25, a movable base 24 threadedly connected to the first screw rod 26, and multiple sets of connecting assemblies evenly distributed around the movable base 24. The second motor 25 can drive the first screw rod 26 to rotate forward and reverse, thereby driving the movable base 24 to move back and forth. The connecting assembly includes a rotating sleeve 22 mounted on the air extraction pipe 8 and a connecting rod 23 rotatably connected to the rotating sleeve 22 and the movable base 24 at both ends. The movable base 24 can drive the rotating sleeve 22 to move via the connecting rod 23, and the rotating sleeve 22 drives the air extraction pipe 8 to move. The multiple sets of connecting assemblies are evenly distributed, so that multiple air extraction pipes 8 can be driven to move inward or outward synchronously.

[0044] This embodiment enables multi-point ammonia mixing detection inside the catalyst 100, thereby obtaining more detailed ammonia mixing distribution data. The test gas is continuously introduced into the catalyst 100's air inlet. The adjustment assembly adjusts the radial position of multiple air extraction pipes 8, enabling the air intake head 81 to extract gas from multiple locations, expanding the air extraction range. The lateral position of the mounting bracket 3 is intermittently adjusted in the direction from the catalyst 100's air inlet to the exhaust port, enabling air extraction from the air intake head 81 at various distances along the air extraction pipe 8 extending into the catalyst 100. By utilizing the gas detection mechanism to detect gas introduced at multiple locations, more detailed ammonia mixing distribution data can be obtained.

[0045] Example 2, as Figures 1-6 As shown, this embodiment proposes an ammonia mixing test device for an automobile exhaust system. Compared to Example 1, in this embodiment, the air intake pipe 8 includes an integrally connected first straight pipe portion, an inclined pipe portion, and a second straight pipe portion. The first straight pipe portion and the second straight pipe portion are parallel to each other, and an air inlet head 81 is located at the outer end of the first straight pipe portion, effectively introducing gas. The connecting pipe 9 includes an integrally connected right-angle pipe portion, a third straight pipe portion, a fourth straight pipe portion, and a fifth straight pipe portion. The second straight pipe portion is in rotational sealing communication with the right-angle pipe portion, and the fifth straight pipe portion is in sliding sealing communication with the air bleed channel of the vent plate 10. When the air intake pipe 8 moves, it can drive the connecting pipe 9 to move, and the connecting pipe 9 maintains communication with the air bleed channel.

[0046] The second straight tube portion of the air extraction pipe 8 is rotatably arranged on the slider 7 and the rotating sleeve 22. When adjusting the spacing between the multiple air extraction pipes 8, the rotating sleeve 22 can still drive the air extraction pipe 8 to move. A first gear 15 is provided on the second straight tube portion. A limiting assembly for limiting and releasing the limit of the first gear 15 is provided on the mounting assembly, and each first gear 15 corresponds to a set of limiting assemblies. A third motor 28 is provided on the mounting platform 6. The third motor 28 is driven and connected to the second gear 27. When the multiple air extraction pipes 8 are retracted to the extreme position, the first gear 15 is engaged with the second gear 27, and the limiting assembly releases the limit on the first gear 15, so that the third motor 28 can drive the first gear 15 to rotate by driving the second gear 27, and the first gear 15 drives the second straight tube portion of the air extraction pipe 8 to rotate. The first straight tube portion and the second straight tube portion are staggered, and the first straight tube portion rotates around the second straight tube portion, thereby driving the intake head 81 to rotate, adjusting the distribution orientation of the intake head 81, and then guiding gas at different orientations in the catalyst 100, thereby expanding the point distribution range of the gas guiding and expanding the point range of the gas detection mechanism to detect ammonia mixing.

[0047] The limiting assembly includes a stopper 21 mounted on the mounting platform 6, a fixed plate 16 mounted on the slider 7, a sliding post 17 slidably mounted on the fixed plate 16, a movable frame 18 and a connecting platform 20 connected to both ends of the sliding post 17, a rack 19 mounted on the movable frame 18 and facing the first gear 15, and a spring 171 mounted on the sliding post 17 and connected to the fixed plate 16 and the connecting platform 20 at both ends, with the connecting platform 20 facing the stopper 21. When the first gear 15 is not engaged with the second gear 27, the spring 171 pushes the connecting platform 20 to its limit position, causing the movable frame 18 to abut against the fixed plate 16, and the rack 19 to engage the first gear 15 to limit the position, preventing the air intake pipe 8 from rotating. To adjust the orientation of the air intake head 81, the adjustment assembly moves the multiple air intake pipes 8 inward. This moves the first gear 15, which in turn, via the slider 7, drives the fixing plate 16 inward. The connecting platform 20 moves toward the stop 21. When the connecting platform 20 abuts the stop 21, it continues to move. The fixing plate 16 slides on the slide post 17, further compressing the spring 171 between the fixing plate 16 and the connecting platform 20. The first gear 15 disengages from the rack 19 and engages the second gear 27. At this point, the third motor 28 drives the second gear 27 to rotate, driving the first gear 15 to adjust the orientation of the air intake head 81 at the front end of the air intake pipe 8. The catalyst 100 is narrow at both ends and wide in the middle. When the first straight portion of the air intake pipe 8 rotates outward relative to the second straight portion, the air intake head 81 can rotate to the wider position inside the catalyst 100 for air guidance.

[0048] After the orientation is adjusted, the multiple air intake pipes 8 are adjusted outward through the adjustment assembly, disengaging the first gear 15 from the second gear 27 and allowing the first gear 15 to be restrained again by the rack 19. When the air intake pipes 8 are subjected to air pressure, they tend to drive the first gear 15 to rotate, but this is insufficient to overcome the friction between the slide post 17 and the fixed plate 16. Therefore, when the rack 19 is engaged with the first gear 15, the first gear 15 does not push the rack 19 outward, and the first gear 15 is effectively restrained.

[0049] The test method of the above-mentioned automobile exhaust system ammonia mixing test equipment comprises the following steps:

[0050] S1. Place the catalyst 100 to be tested on the support 2;

[0051] S2. Start the second motor 25, which drives the first screw 26 to rotate. The multiple connecting components drive the multiple air extraction pipes 8 to close until the first gear 15 and the second gear 27 are engaged. At this time, the rack 19 is disengaged from the first gear 15, and the second motor 25 can drive the first screw 26 to rotate forward and reverse.

[0052] S3. Start the third motor 28, which drives the second gear 27 to rotate. The second gear 27 drives the air intake pipe 8 to rotate via the first gear 15, rotating the first straight pipe portions of the multiple air intake pipes 8 inward, reducing the spacing between the multiple air intake heads 81. The multiple air intake heads 81 are retracted, making it easier to extend the multiple air intake pipes 8 through the narrow exhaust port of the catalyst 100.

[0053] S4. The mounting frame 3 is driven to move horizontally by the transverse movement mechanism, and the plurality of air intake heads 81 are extended from the exhaust port of the catalyst 100 into the interior of the catalyst 100 until the air intake heads 81 move to one side of the air intake port;

[0054] S5. The test gas is continuously introduced into the catalyst 100 through the air inlet, and the catalyst 100 is activated synchronously. A preset period of time is waited for the gas to be evenly introduced and the catalyst 100 to stabilize.

[0055] S6. The connecting disk 11 is driven to rotate by the first motor 14, and the air passage 111 connects the air bleed pipe 12 with one of the multiple connecting pipes 9. Each time one of the connecting pipes 9 is connected, the air inlet head 81 on the air intake pipe 8 corresponding to the connecting pipe 9 introduces gas into the air intake pipe 8. The air intake pipe 8 transports the gas to the gas detection mechanism through the connecting pipe 9, the ventilation disk 10, the connecting disk 11, and the air bleed pipe 12. When one connecting pipe 9 is connected with the air passage 111 and the air bleed pipe 12, the remaining connecting pipes 9 are not connected with the air passage 111 or the air bleed pipe 12. Gas can only be introduced from one air inlet head 81 at a time. The air passage 111 rotates due to the rotation of the connecting disk 11, switching to connect with the multiple connecting pipes 9 in sequence. The gas detection mechanism performs ammonia mixing detection on the gases introduced by the multiple air inlet heads 81 in sequence.

[0056] S7. Start the second motor 25, which intermittently drives the first screw 26 to rotate in the opposite direction. The first gear 15 disengages from the second gear 27, and the rack 19 is locked on the first gear 15 for limiting. The gas pipe 8 intermittently moves outward by a preset distance. During each intermittent period of stopping the outward movement, step S6 is performed. The gas detection mechanism sequentially detects ammonia mixing with the gas introduced by the multiple gas inlet heads 81, further expanding the number of detection points based on the detection points in step S6.

[0057] S8. Re-engage the first gear 15 with the second gear 27, start the third motor 28, and adjust the distribution position of the gas inlet head 81 at the front end of the gas intake pipe 8, that is, adjust the distribution orientation of the gas inlet head 81 relative to the second straight pipe portion. Then, repeat steps S6-S7. The gas detection mechanism sequentially performs ammonia mixing detection on the gas introduced by the multiple gas inlet heads 81, and performs gas detection at more points.

[0058] S9. The traversing mechanism intermittently drives the mounting frame 3 to move away from the exhaust port of the catalyst 100. Step S8 is performed during each intermittent period of traversing. This allows gas to be introduced at different distances from the air intake head 81 into the interior of the catalyst 100, and the ammonia mixing data is detected using the gas detection mechanism, thereby achieving the purpose of multi-point ammonia mixing detection inside the catalyst 100. When the air intake head 81 finally needs to be removed from the catalyst 100, the multiple air intake pipes 8 are pre-assembled to reduce the spacing between the multiple air intake heads 81, allowing the air intake pipes 8 and the air intake head 81 to be removed from the exhaust port of the catalyst 100 and avoiding interference.

[0059] In this embodiment, the air intake head 81 can rotate around the second straight pipe portion of the air intake pipe 8, and the air intake head 81 can also move in a straight line toward the inner wall of the catalyst 100, and move along the direction from the air inlet to the exhaust port of the catalyst 100, which greatly increases the number of detection points. The points are densely distributed, and the use of a gas detection mechanism to detect ammonia mixing data can reflect the ammonia mixing distribution in more detail.

[0060] Example 3, as Figures 1-6As shown, this embodiment proposes an ammonia mixing test device for an automobile exhaust system. Compared to Example 1, in this embodiment, the air duct 12 is connected to an exhaust pipe. The exhaust pipe can be connected to the middle of the air duct 12. A control valve is provided on the exhaust pipe, and the exhaust pipe is connected to an exhaust pump. Multiple air ducts 13 are evenly connected to the periphery of the vent plate 10. The multiple air ducts 13 are spaced apart from the multiple air duct channels on the vent plate 10, and a filter is provided on the air duct 13. When the gas detection mechanism detects the gas transported by the air duct 12, the control valve on the exhaust pipe is closed. When the connecting plate 11 rotates until the air channel 111 connects to the air duct 13, the rotation is stopped, the control valve is opened, and the exhaust pump is started. After being filtered by the filter, the outside air can pass through the air duct 13 and the air channel 111 and enter the air duct 12. The remaining gas in the air duct 12 can be discharged from the exhaust pump through the exhaust pipe. Then close the control valve, and rotate the connecting disk 11 to the position where the airway 111 is connected to the connecting pipe 9. The air inlet head 81 introduces the gas at the corresponding point. The gas is transported to the gas detection mechanism through the airway 111 and the air duct 12 for detection. Before each gas detection, the residual gas from the last gas detection is discharged to ensure the accuracy of the detection results.

[0061] The embodiments of the present invention are described in detail above with reference to the accompanying drawings, but the present invention is not limited thereto. Various changes can be made within the scope of knowledge possessed by those skilled in the art without departing from the spirit of the present invention.

Claims

1. An ammonia mixing test device for an automobile exhaust system, used for performing an ammonia mixing test on a catalyst (100), the catalyst (100) having an air inlet and an exhaust port, characterized in that: include: An air extraction device comprises a mounting frame (3), a mounting assembly arranged on the mounting frame (3), a plurality of air extraction pipes (8) evenly distributed around the mounting assembly, and an adjustment assembly arranged on the mounting frame (3) and adjusting the spacing between the plurality of air extraction pipes (8), wherein the front end of the air extraction pipe (8) has an air inlet head (81); A gas transmission device comprises a vent disc (10) having a plurality of air ducts uniformly distributed around a central axis and radially arranged on its outer periphery, a connecting disc (11) provided with an air duct (111) and provided with a rotary seal on the vent disc (10), a first motor (14) for driving the connecting disc (11) to rotate, a connecting pipe (9) connected to the air duct in a radially sliding seal, and an air duct (12) connected to the outlet of the air duct (111) by a rotary seal, wherein the vent disc (10) and the first motor (14) are both provided on a mounting frame (3), the outlet of the air duct (111) is located in the middle of the connecting disc (11), the inlet of the air duct (111) is located on the circumferential surface of the connecting disc (11), the connecting pipe (9) is connected to the air extraction pipe (8), and when the connecting disc (11) rotates, the air duct (111) connects the air duct (12) to one of the plurality of connecting pipes (9); a gas detection mechanism, which is in communication with the air bleed pipe (12); A base (1) is provided with a support base (2) for supporting the catalyst (100), and a transverse movement mechanism for driving the mounting frame (3) to move horizontally to adjust the distance that the air intake pipe (8) extends into the interior of the catalyst (100); The mounting assembly includes a connecting frame (4) arranged on the mounting frame (3), a plurality of slide rails (5) evenly distributed in a ring shape on the connecting frame (4), a mounting platform (6) arranged on the slide rails (5), and a slider (7) slidably arranged on the slide rails (5), and an air extraction pipe (8) is arranged on the slider (7); The regulating assembly includes a second motor (25) arranged on the mounting frame (3), a first screw rod (26) rotatably arranged on the mounting frame (3) and connected to the output end of the second motor (25), a movable seat (24) threadedly connected to the first screw rod (26), and a plurality of connecting assemblies evenly distributed around the movable seat (24), the connecting assembly including a rotating sleeve (22) arranged on the air extraction pipe (8) and a connecting rod (23) with two ends respectively rotatably connected to the rotating sleeve (22) and the movable seat (24); The air duct (12) is connected to an air extraction pipe, a control valve is provided on the air extraction pipe, and the air extraction pipe is connected to an air extraction pump. The outer periphery of the ventilation plate (10) is evenly connected to multiple ventilation pipes (13), the multiple ventilation pipes (13) are spaced apart from the multiple air ducts, and a filter is provided at the ventilation pipe (13).

2. The automobile exhaust system ammonia mixing test equipment according to claim 1, characterized in that: A crossbar (29) is provided at the front of the mounting platform (6), and a flow guide platform (30) is provided at the front end of the crossbar (29). The flow guide platform (30) is located between the plurality of air extraction pipes (8). The flow guide platform (30) has a conical flow guide surface, the top of the conical flow guide surface is located on the side away from the crossbar (29), and the conical flow guide surface is concave inward.

3. The automobile exhaust system ammonia mixing test equipment according to claim 1, characterized in that: The air intake pipe (8) includes a first straight pipe portion, an oblique pipe portion, and a second straight pipe portion that are connected in an integral manner. The first straight pipe portion and the second straight pipe portion are parallel to each other, and the air intake head (81) is located at the outer end of the first straight pipe portion. The connecting pipe (9) includes a right-angle pipe portion, a third straight pipe portion, a fourth straight pipe portion, and a fifth straight pipe portion that are connected in an integral manner. The second straight pipe portion is connected to the right-angle pipe portion in a rotating sealing manner, and the fifth straight pipe portion is connected to the air inlet channel of the vent plate (10) in a sliding sealing manner.

4. The automobile exhaust system ammonia mixing test equipment according to claim 3, characterized in that: The second straight tube portion of the air extraction pipe (8) is rotatably arranged on the slider (7) and the rotating sleeve (22), the second straight tube portion is provided with a first gear (15), the mounting assembly is provided with a limiting assembly for limiting and releasing the limit on the first gear (15), the mounting platform (6) is provided with a third motor (28), the third motor (28) is driven and connected to the second gear (27), when the multiple air extraction pipes (8) are retracted to the limit position, the first gear (15) is engaged with the second gear (27), and the limiting assembly releases the limit on the first gear (15).

5. The automobile exhaust system ammonia mixing test equipment according to claim 4, characterized in that: The limiting assembly includes a stopper (21) arranged on the mounting platform (6), a fixed plate (16) arranged on the slider (7), a sliding column (17) slidably arranged on the fixed plate (16), a movable frame (18) and a connecting platform (20) respectively connected to both ends of the sliding column (17), a rack (19) arranged on the movable frame (18) and facing the first gear (15), and a spring (171) sleeved on the sliding column (17) and connected to the fixed plate (16) and the connecting platform (20) at both ends, and the connecting platform (20) faces the stopper (21).

6. The automobile exhaust system ammonia mixing test equipment according to claim 1, characterized in that: The transverse movement mechanism comprises a second screw rod (34) horizontally rotatably arranged on the base (1), a guide rod (35) parallel to the second screw rod (34) and arranged on the base (1), a fourth motor (33) arranged on the base (1) and drivingly connected to the second screw rod (34), a support frame (31) arranged at the bottom of the mounting frame (3), and a movable platform (32) arranged at the bottom of the support frame (31), wherein the movable platform (32) is slidably arranged on the guide rod (35) and is threadedly connected to the second screw rod (34).

7. A method for testing ammonia mixing in an automobile exhaust system, implemented by the automobile exhaust system ammonia mixing testing device according to claim 5, characterized in that: The test method includes the following steps: S1, placing the catalyst to be tested (100) on the support (2); S2, starting the second motor (25), the second motor (25) drives the first screw (26) to rotate, and the multiple connecting components drive the multiple air extraction pipes (8) to close to the position where the first gear (15) and the second gear (27) are engaged. At this time, the rack (19) is disengaged from the first gear (15); S3, starting the third motor (28), the third motor (28) drives the second gear (27) to rotate, the second gear (27) drives the air intake pipe (8) to rotate through the first gear (15), and the first straight pipe parts of the plurality of air intake pipes (8) are rotated inward, thereby reducing the distance between the plurality of air intake heads (81); S4, driving the mounting frame (3) to move horizontally by means of a transverse movement mechanism, extending the plurality of air intake heads (81) from the exhaust port of the catalyst (100) into the interior of the catalyst (100) until the air intake heads (81) move to one side of the air intake port; S5, continuously introducing the gas to be tested from the air inlet of the catalyst (100), and the catalyst (100) is activated synchronously; S6. The connecting disk (11) is driven to rotate by the first motor (14), and the air passage (111) connects the air duct (12) to one of the plurality of connecting tubes (9). Each time one of the connecting tubes (9) is connected, the air inlet head (81) on the air extraction tube (8) correspondingly connected to the connecting tube (9) introduces gas into the air extraction tube (8). The air extraction tube (8) transmits the gas to the gas detection mechanism through the connecting tube (9), the vent disk (10), the connecting disk (11) and the air duct (12). The gas detection mechanism sequentially performs ammonia mixing detection on the gas introduced by the plurality of air inlet heads (81); S7, start the second motor (25), the second motor (25) intermittently drives the first screw (26) to rotate in the opposite direction, the first gear (15) disengages from the second gear (27), the rack (19) is clamped on the first gear (15) to limit the position, the gas pipe (8) intermittently moves outward, and step S6 is performed in each intermittent time period when the movement stops, and the gas detection mechanism sequentially performs ammonia mixing detection on the gas introduced by the multiple gas inlet heads (81); S8, re-engage the first gear (15) and the second gear (27), start the third motor (28), adjust the distribution position of the gas inlet head (81) at the front end of the gas intake pipe (8), and then repeat steps S6-S7, and the gas detection mechanism sequentially performs ammonia mixing detection on the gases introduced by the multiple gas inlet heads (81); S9, intermittently driving the mounting frame (3) to move away from the exhaust port of the catalyst (100) through the transverse movement mechanism, and performing step S8 in each intermittent period of stopping the transverse movement, thereby achieving the purpose of multi-point ammonia mixing detection inside the catalyst (100).

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