Coaxial positioning type automobile exhaust detection sampling device

Abstract

The invention discloses a coaxial positioning type automobile exhaust detection sampling device. The device comprises two coaxial ring supporting pieces which are axially distributed at intervals, and a positioning hole for a probe to penetrate through is formed in the center of each ring supporting piece. At least two groups of parallel four-connecting-rod structures are uniformly distributed along the circumference, and the rack is connected with the circular ring supporting piece through a revolute pair. The miniature telescopic rod component is connected with two opposite rotating pairs in the parallel four-connecting-rod structure, and an air cavity of the miniature telescopic rod component is connected with the manual inflator pump through a high-temperature-resistant air pipe. And the manual inflation pump is integrated with a manual pressure release valve. According to the device, the parallel four-connecting-rod mechanism is radially expanded by inflating the air cavity, so that the sampling probe can be accurately and coaxially fixed in the center of the exhaust pipe, and the probe is effectively prevented from deviating or inclining. The technical problems of inaccurate probe positioning and front end inclination in tail gas detection are solved, and the sampling efficiency and accuracy are improved.

Description

Technical Field

[0001] This invention relates to the field of exhaust gas detection probes, and more specifically to a coaxial positioning automotive exhaust gas detection and sampling device. Background Technology

[0002] Currently, in the field of vehicle exhaust emission testing, to accurately measure exhaust gas components, it is usually necessary to insert a sampling probe into the vehicle's exhaust pipe. However, existing sampling probe positioning methods generally face several technical challenges. Firstly, it is difficult to precisely align the probe with the central axis of the exhaust pipe during insertion, causing the probe to easily deviate from its central position. Even worse, the axis of the sampling tube may be tilted within the exhaust pipe, meaning there is an angle between the axis of the sampling tube and the axis of the exhaust pipe. This prevents the sampling head from directly facing the exhaust gas flow, thus reducing the effective intake cross-sectional area and severely impacting sampling efficiency and the accuracy of the results. Summary of the Invention

[0003] The purpose of this invention is to provide a coaxial positioning automotive exhaust gas detection and sampling device to solve the technical problems in existing exhaust gas detection where the sampling probe is difficult to achieve stable and accurate coaxial positioning inside the exhaust pipe, and difficult to pull out smoothly after positioning.

[0004] To solve the above-mentioned technical problems, the present invention specifically provides the following technical solution:

[0005] A coaxial positioning vehicle exhaust gas detection and sampling device includes:

[0006] Two circular support members are arranged coaxially and are spaced apart along their axial direction. A positioning hole for the sampling probe to pass through is formed at the center of each circular support member.

[0007] At least two sets of parallel four-bar linkages are evenly distributed along the circumference on the outside of the ring support. The two ends of the frame of each parallel four-bar linkage are connected to the two ring support members through a rotating joint.

[0008] The number of miniature telescopic rod components is matched with the number of parallel four-bar linkages. Each miniature telescopic rod component is connected to two opposite rotating pairs in the corresponding parallel four-bar linkage structure at both ends.

[0009] The number of high-temperature resistant air tubes is matched with the number of miniature telescopic rod components. Each miniature telescopic rod component has an air chamber for sealing and containing air. The high-temperature resistant air tube has a distal opening and a proximal opening. The distal opening of each high-temperature resistant air tube is connected to the corresponding air chamber.

[0010] A manual air pump is provided, and all the proximal openings of the high-temperature resistant air tubes are connected to the manual air pump, which is equipped with a manual pressure relief valve.

[0011] The sampling tube has two circular support members fixedly sleeved on its front end;

[0012] The handle is connected to the front end of the sampling tube, and the sampling tube and the through hole in the handle together form the sampling channel for collecting exhaust gas.

[0013] Furthermore, the parallel four-bar structure includes:

[0014] The base rod, which is the aforementioned frame, has two circular support members connected to both ends of it via a revolute joint;

[0015] There are two cranks, which are parallel to each other. The same end of each crank is connected to the two ends of the base rod through a revolute joint.

[0016] The floating rod is parallel to the base rod, and its two ends are connected to the other ends of the two crank rods through revolute joints.

[0017] Furthermore, the miniature telescopic rod component includes:

[0018] The central rod has one end connected to a revolute joint of a parallel four-bar linkage;

[0019] Hollow tube, which is a structure with one end open and the other end closed. The other end of the central rod is inserted into the open end of the hollow tube in a dynamically sealed state. The closed end of the hollow tube is connected to another rotating pair of the parallel four-bar linkage structure.

[0020] Among them, the miniature telescopic rod component is set as a diagonal link in a parallel four-bar linkage structure;

[0021] The air cavity is formed on the inner side of the insertion end of the central rod and the closed end of the hollow rod.

[0022] Furthermore, each parallel four-bar structure is configured such that, in the uninflated state of the air chamber, the insertion end of the floating rod is positioned further forward in the axial direction than the insertion end of the base rod.

[0023] Furthermore, each parallel four-bar structure is configured such that even when the air chamber is filled with air so that all floating rods simultaneously press against the exhaust pipe wall, the insertion end of the floating rod is still further forward in the axial direction than the insertion end of the base rod.

[0024] Furthermore, the inflation port of the manual air pump is connected to the proximal opening of all high-temperature resistant air pipes via a shunt connector.

[0025] Furthermore, several tubing guides for organizing high-temperature resistant gas tubing are distributed on the sampling tube and handle.

[0026] Furthermore, a metal bushing is formed at the front end of the sampling tube, and several radially extending baffles are formed on the outer side of the metal bushing. A clearance channel is formed between every two adjacent radially extending baffles to avoid the tilting movement of the parallel four-bar linkage structure.

[0027] A limiting device is also fitted onto the sampling tube. The limiting device is in the shape of a round tube, and several shrinkage notches are evenly distributed in the circumferential direction on its side wall. One end of the limiting device is formed with an annular baffle that extends radially.

[0028] The cylindrical outer wall of the limiting kit is formed with threads, and a hand-tightening cap is provided on the outer side of the limiting kit and screwed into the threaded part. A tapered fit structure is designed between the limiting kit and the hand-tightening cap, so that the hand-tightening cap converts the axial force into a radial force that causes the limiting kit to contract radially by tightening the thread.

[0029] Both annular supports are located between the radially extending baffle and the annular baffle, which respectively restrict the movement of the two annular supports along the axial direction of the sampling tube.

[0030] The beneficial effects of this invention are as follows: This retainer, through two coaxial and axially spaced annular support members (forming a two-point support) and their positioning holes, not only guides the probe to be centered, but also effectively avoids the tilting of the front end of the sampling probe, ensuring that it is as coaxial as possible with the exhaust pipe and ensuring that the front of the sampling port faces the airflow; at least two sets of parallel four-bar structures expand radially evenly when the air chamber is filled with air, so that it is tightly pressed against the exhaust pipe wall, thereby accurately coaxially positioning and stably fixing the sampling probe in the center of the exhaust pipe, which significantly improves the sampling efficiency and accuracy. Attached Figure Description

[0031] To more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings in the following description are merely exemplary, and those skilled in the art can derive other embodiments based on the provided drawings without creative effort.

[0032] Figure 1 This is a schematic diagram of the planar structure of the retainer and probe assembly in the retracted state of the present invention;

[0033] Figure 2 This is a schematic diagram of the planar structure of the retainer and probe assembly in the open state of the present invention;

[0034] Figure 3 This is a schematic diagram of the main structure of the retainer of the present invention in a retracted state;

[0035] Figure 4This is a schematic diagram of the main structure of the retainer of the present invention in an open state;

[0036] Figure 5 for Figure 3 Enlarged schematic diagram of the structure at point A in the diagram;

[0037] Figure 6 for Figure 3 Enlarged schematic diagram of the structure at point B in the diagram;

[0038] The labels in the diagram represent the following: 1- Circular support; 2- Parallel four-bar structure; 3- Miniature telescopic rod component; 4- High-temperature resistant air tube; 5- Air chamber; 6- Manual air pump; 7- Manual pressure relief valve; 8- Base rod; 9- Crank rod; 10- Floating rod; 11- Center rod; 12- Hollow tube; 13- Diverter connector; 14- Sampling tube; 15- Handle; 16- Conduit guide; 17- Pipe interface; 18- Metal bushing; 19- Radial extension baffle; 20- Clearance channel; 21- Limiting kit; 22- Circular baffle; 23- Hand-tightening cap; 24- Exhaust pipe. Detailed Implementation

[0039] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0040] Reference Figures 1 to 6 As shown, the core support structure of this coaxial positioning probe holder consists of two circular support members 1. These two support members are spatially coaxial and distributed at a predetermined interval along the axial direction. This coaxial design lays the foundation for the coaxial positioning of the entire holder from the outset. A positioning hole is precisely formed at the center of each circular support member 1. This positioning hole serves as a channel through which the sampling probe passes, guiding the sampling probe into the central axis of the holder and providing it with initial radial constraint within the holder. This ensures that the probe can move stably along the expected centerline during subsequent positioning, which is the first step in coaxial probe positioning.

[0041] Around the outer sides of the two circular support members 1, at least two sets of parallel four-bar structures 2 are cleverly arranged, evenly distributed along the circumference. This uniform distribution ensures that the retainer can apply a uniform force to the exhaust pipe wall during radial expansion, thereby achieving stable coaxial positioning. The core of each set of parallel four-bar structures 2 is its frame. This frame is called the base rod 8, and its two ends are connected to the two circular support members 1 respectively through revolute joints. This connection method allows the base rod 8 to be firmly fixed on the circular support members 1, serving as the fixed reference for the entire parallel four-bar mechanism. Each set of parallel four-bar structures 2 also includes two parallel crank rods 9, which are connected to the two ends of the base rod 8 respectively through revolute joints. Connecting the other ends of these two crank rods 9 is a floating rod 10, which is parallel to the base rod 8. In the motion characteristics of the parallel four-bar mechanism, the floating rod 10 will translate while maintaining its own direction during movement, which provides the basis for achieving uniform radial expansion.

[0042] The key to driving the expansion and contraction of these parallel four-bar structures 2 lies in the micro telescopic rod components 3. The number of these telescopic rod components matches the number of parallel four-bar structures 2, with each telescopic rod precisely connected at both ends to two opposing revolute joints of the corresponding parallel four-bar structure 2. Each micro telescopic rod component 3 is designed as a diagonal link, its internal structure containing a central rod 11 and a hollow tube 12. One end of the central rod 11 is connected to one revolute joint of the parallel four-bar structure, while its other end is inserted into the open end of the hollow tube 12 in a dynamically sealed manner. The closed end of the hollow tube 12 is connected to the other opposing revolute joint of the parallel four-bar structure. The inserted end of the central rod 11 and the inner side of the closed end of the hollow tube 12 form an air chamber 5 for sealing and containing air. When the air chamber 5 is inflated, the central rod 11 extends relative to the hollow tube 12 under pressure, thereby forcing the parallel four-bar structure 2 to open outwards; when the air chamber 5 is depressurized, the telescopic rod contracts accordingly, causing the parallel four-bar structure 2 to retract inwards. This ingenious pneumatic telescopic design enables precise and controllable adjustment of the retainer size.

[0043] To power these air chambers 5, this embodiment is equipped with high-temperature resistant air tubes 4, the number of which matches the number of miniature telescopic rod components 3. Each high-temperature resistant air tube 4 has a distal opening and a proximal opening, with the distal opening communicating with the corresponding air chamber 5. A pipe interface 17 for connecting the high-temperature resistant air tube 4 to the air chamber 5 is provided on the side wall of the hollow tube 12. Considering the special nature of the exhaust gas detection environment, the air tubes are made of high-temperature resistant materials to ensure stable operation even in high-temperature exhaust gases. The proximal openings of all the high-temperature resistant air tubes 4 converge and are connected to a manual inflation pump 6. According to the design, the inflation port of the manual inflation pump 6 is connected to the proximal openings of all the high-temperature resistant air tubes 4 via a shunt connector 13, ensuring that all air chambers 5 can receive or release air pressure synchronously. This manual inflation pump 6 is the control center of the entire inflation / depressurization system, and its most critical feature is the integration of a manual pressure relief valve 7. This manual pressure relief valve 7 allows the operator to actively and precisely control the pressure release within the air chambers 5 when needed. It provides the ability to directly intervene in the depressurization process, making the contraction of the retainer and the removal of the probe more controllable and smooth.

[0044] The unique feature of this retainer lies in the preset tilt angle of the parallel four-bar linkage and its retention in the working state. When the air chamber 5 is not inflated, each parallel four-bar structure 2 is carefully configured such that the insertion end of its floating rod 10 is further forward in the axial direction than the insertion end of the base rod 8. This preset tilt lays the foundation for smooth subsequent removal. Even more ingeniously, even when the air chamber 5 is inflated, causing all floating rods 10 to simultaneously press against the exhaust pipe wall, this relationship of the insertion end of the floating rod 10 being further forward in the axial direction than the insertion end of the base rod 8 still exists. This characteristic is a core technical point of this invention. When the retainer is fully inflated and firmly fixed inside the exhaust pipe, its contact with the pipe wall is not perpendicular, but maintains a certain tilt angle. When the probe needs to be removed, the frictional force generated by the exhaust pipe wall on the floating rod 10 is decomposed into a component force that actively promotes the inward contraction of the floating rod 10 due to this forward tilt angle, rather than an expansion force that hinders contraction or causes jamming. This design effectively avoids the "locking" or "jamming" phenomenon that may occur when the mechanism is under stress, greatly improves the smoothness and reliability when pulling out the probe, reduces potential damage to the equipment or exhaust pipe, and reflects ingenious application of mechanics and consideration for the convenience of actual operation.

[0045] Furthermore, this embodiment also provides a sampling probe assembly (the sampling probe assembly and the aforementioned probe holder together constitute the automotive exhaust gas detection sampling device of the present invention), which integrates the aforementioned probe holder. The assembly comprises a sampling tube 14, with the probe holder precisely positioned at the front end of the sampling tube 14. The other end of the sampling tube 14 is connected to the front end of a handle 15. The sampling tube 14 and the through-hole inside the handle 15 together form a complete sampling channel for collecting exhaust gas, allowing the exhaust gas to be introduced into the detection device through this channel. To ensure the cleanliness and functional stability of the entire assembly during actual operation, several conduit guides 16 for organizing the high-temperature resistant gas tubes 4 are also distributed on the sampling tube 14 and the handle 15. These guides effectively manage and fix the high-temperature resistant gas tubes 4 connecting each gas chamber 5, preventing them from tangling, wearing, or interfering with operation during use, further improving the overall reliability of the assembly and the user experience.

[0046] Furthermore, to optimize the connection and positioning of the retainer and sampling tube 14, a metal bushing 18 is formed at the front end of the sampling tube 14, and several radially extending baffles 19 are formed on its outer side. An obstacle avoidance channel 20 is formed between every two adjacent radially extending baffles 19 to avoid the tilting movement of the parallel four-bar linkage 2. This ensures that when the parallel four-bar linkage 2 tilts during contraction or expansion, it will not interfere with the bushing on the sampling tube 14. A positioning kit 21 is also fitted onto the sampling tube 14. This kit is cylindrical, with several circumferentially distributed contraction notches on its sidewalls, and a radially extending annular baffle 22 formed at one end. The cylindrical outer wall of the positioning kit 21 is threaded, and a hand-tightening cap 23 is screwed onto the threaded portion on its outer side. The thread formed on the cylindrical outer wall of the limiting kit 21 mates with the internal thread of the hand-tightening cap 23. Specifically, the outer wall of the limiting kit 21 or the inner wall of the hand-tightening cap 23 is designed with a taper. This taper mates with the corresponding thread type or the internal conical surface of the cap, so that when the hand-tightening cap 23 is tightened along the thread, its conical surface will press against the limiting kit 21, converting the axial tightening force into a radial compressive force. This radial compressive force acts on the limiting kit 21, causing the contraction notch on its side wall to close inward, thereby reducing the inner diameter of the limiting kit 21 and ultimately tightly gripping the outer wall of the sampling tube 14, thus further reinforcing the connection between the retainer and the sampling tube 14. In this structure, two annular supports 1 are precisely positioned between a radially extending baffle 19 and an annular baffle 22. The radially extending baffle 19 and the annular baffle 22 together restrict the movement of the two annular supports 1 along the axial direction of the sampling tube 14, thereby providing a robust boundary for the axial positioning of the probe holder within the sampling tube 14 and ensuring the overall stability and reliability of the system.

[0047] The above embodiments are merely exemplary embodiments of the present invention and are not intended to limit the present invention. The scope of protection of the present invention is defined by the claims. Those skilled in the art can make various modifications or equivalent substitutions to the present invention within its spirit and scope of protection, and such modifications or equivalent substitutions should also be considered as falling within the scope of protection of the embodiments of the present invention.

Claims

1. A coaxial positioning type vehicle exhaust gas detection and sampling device, characterized in that, include: Two circular support members (1) are coaxial and spaced apart along their axial direction. A positioning hole for the sampling probe to pass through is formed at the center of each circular support member (1). At least two sets of parallel four-bar structures (2) are evenly distributed along the circumferential direction on the outside of the circular ring support (1), and the two ends of the frame of each parallel four-bar structure (2) are connected to the two circular ring support members (1) through a rotating joint; The number of miniature telescopic rod components (3) is matched with the number of parallel four-bar structures (2), and each of the miniature telescopic rod components (3) is connected to two opposite rotating pairs in the corresponding parallel four-bar structures (2) at both ends. The number of high-temperature resistant air tubes (4) is matched with the number of the micro telescopic rod components (3). Each micro telescopic rod component (3) has an air chamber (5) for sealing and containing air. The high-temperature resistant air tubes (4) have a distal opening and a proximal opening. The distal opening of each high-temperature resistant air tube (4) is connected to the corresponding air chamber (5). Manual air pump (6), all the proximal openings of the high-temperature resistant air pipes (4) are connected to the manual air pump (6), and the manual air pump (6) is integrated with a manual pressure relief valve (7); The sampling tube (14) has two ring support members (1) fixedly sleeved on the front end of the sampling tube (14); The handle (15) is connected to the front end of the sampling tube (14), and the sampling tube (14) and the through hole in the handle (15) together form a sampling channel for collecting exhaust gas.

2. The coaxial positioning type automobile exhaust gas detection and sampling device according to claim 1, characterized in that, The parallel four-bar structure (2) includes: The base rod (8) is the frame mentioned above. Both ends of the base rod (8) are connected to the two ring support members (1) through a rotating joint. There are two crank rods (9) in parallel. The same end of the two crank rods (9) is connected to the two ends of the base rod (8) through a revolute joint. A floating rod (10) is parallel to the base rod (8), and the two ends of the floating rod (10) are respectively connected to the other ends of the two crank rods (9) through a rotating joint.

3. The coaxial positioning type vehicle exhaust gas detection and sampling device according to claim 1, characterized in that, The miniature telescopic rod component (3) includes: The central rod (11) has one end connected to a rotating joint of the parallel four-bar linkage (2); Hollow tube (12), the hollow tube (12) has a structure with one end open and the other end closed, the other end of the central rod (11) is inserted into the open end of the hollow tube (12) in a dynamically sealed state, and the closed end of the hollow tube (12) is connected to another rotating pair of the parallel four-bar structure (2); The micro telescopic rod component (3) is configured as a diagonal link of the parallel four-bar structure (2); The insertion end of the central rod (11) and the inner side of the closed end of the hollow rod form the air cavity (5).

4. The coaxial positioning type automobile exhaust gas detection and sampling device according to claim 2, characterized in that, Each of the parallel four-bar structures (2) is configured such that, in the uninflated state of the air chamber (5), the insertion end of the floating rod (10) is further forward in the axial direction from the insertion end of the base rod (8).

5. The coaxial positioning type automobile exhaust gas detection and sampling device according to claim 4, characterized in that, Each of the parallel four-bar structures (2) is configured such that even when the air chamber (5) is inflated so that all the floating rods (10) simultaneously press against the exhaust pipe wall, the insertion end of the floating rod (10) is still further forward in the axial direction of the insertion end of the base rod (8).

6. The coaxial positioning type vehicle exhaust gas detection and sampling device according to claim 1, characterized in that, The air inlet of the manual air pump (6) is connected to the proximal opening of all the high-temperature resistant air pipes (4) via a shunt connector (13).

7. The coaxial positioning type vehicle exhaust gas detection and sampling device according to claim 1, characterized in that, Several conduit guides (16) for organizing the high-temperature resistant gas tube (4) are dispersedly arranged on the sampling tube (14) and the handle (15).

8. The coaxial positioning type automobile exhaust gas detection and sampling device according to claim 1, characterized in that, The front end of the sampling tube (14) is formed with a metal bushing (18), and the outer side of the metal bushing (18) is formed with a number of radially extending baffles (19) evenly distributed in the circumferential direction. A clearance channel (20) is formed between every two adjacent radially extending baffles (19) to avoid the tilting movement of the parallel four-bar linkage (2). A limiting device (21) is also fitted onto the sampling tube (14). The limiting device (21) is in the shape of a round tube, and several shrinkage notches are evenly distributed along the circumference on its side wall. One end of the limiting device (21) is formed with an annular baffle (22) extending radially. The cylindrical outer wall of the limiting kit (21) is formed with threads, and a hand-tightening cap (23) is provided on the outer side of the limiting kit (21) and screwed into the threaded part. A tapered fit structure is designed between the limiting kit (21) and the hand-tightening cap (23). The hand-tightening cap (23) converts the axial force into a radial force that causes the limiting kit (21) to contract radially by tightening the thread. Both of the circular support members (1) are located between the radially extending baffle (19) and the annular baffle (22), which respectively restrict the movement of the two circular support members (1) along the axial direction of the sampling tube (14).

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