Device and method for uniformly mixing powder of catalytic converter for vehicle

Abstract

The invention provides a powder mixing device and method for an automobile catalyst, and relates to the technical field of sample pretreatment, and the device comprises a rack, a mixing cabin, a first driving unit, a second driving unit and a control unit. The mixing cabin is used for accommodating powder to be uniformly mixed; the first driving unit can clamp the first end of the mixing cabin; the second driving unit and the first driving unit are arranged at intervals in the X direction, the interval distance is adjustable, and the second end of the mixing cabin can be clamped; the control unit is electrically connected with the first driving unit and the second driving unit, so that the first driving unit and the second driving unit have controlled rotating speed difference or rotating direction difference during operation, a dead-corner-free dynamic eddy current field is formed in the cabin, and under the action of the dynamic eddy current field, the powder to be uniformly mixed passes through an inertia force field with continuously changing direction and size, so that the powder to be uniformly mixed is uniformly mixed. Violent collision, diffusion and shearing occur among particles, so that high-efficiency uniform mixing is realized.

Description

Technical Field

[0001] This invention generally relates to the field of sample pretreatment technology, and specifically to a device and method for mixing automotive catalyst powder. Background Technology

[0002] With increasingly stringent emission standards for heavy-duty diesel vehicles, the testing of precious metal content such as platinum, palladium, and rhodium in automotive catalytic converters has become a mandatory requirement. Automotive catalytic converters, especially those for diesel vehicles, are typically large and heavy, but have extremely low effective loadings of precious metals (usually below 0.1%), and suffer from uneven coating during manufacturing. This results in highly uneven composition distribution in the original powder samples obtained from the catalytic converter.

[0003] In existing technologies, when pre-treating large-volume, low-content powders in laboratories, the process often relies on traditional sample dividers (such as rotary samplers) or manual stirring and tumbling. Traditional sample dividers require multiple sample division and merging cycles, which are cumbersome and time-consuming. Furthermore, they are difficult to completely eliminate the inherent layering and agglomeration of powders, resulting in poor representativeness of the final test samples. The deviation in precious metal content test results can reach 20% to 50%. While large-scale industrial mixing equipment (such as V-type mixers and three-dimensional motion mixers) provides better mixing results, they generally suffer from problems such as large size, high cost, high energy consumption, complex operation, and difficult cleaning. These issues make them unsuitable for the laboratory environment's requirements for high precision, prevention of cross-contamination, and convenient operation of trace powders.

[0004] Therefore, there is an urgent need in the field for a powder mixing device and method for automotive catalysts to solve the problem of homogenization of powders with characteristics of "large volume, low content, and layered coating" such as automotive catalysts, and to ensure the accuracy and reliability of subsequent component detection, especially the detection of precious metal content. Summary of the Invention

[0005] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide a vehicle catalyst powder mixing device and method to solve the above problems.

[0006] The first aspect of this invention provides a vehicle catalyst powder mixing device, comprising: A frame, on which a mixing chamber is connected, the mixing chamber being used to hold powder to be mixed; The first drive unit includes a first drive motor, a first reducer, and a first drive head; the first drive motor is connected to the frame, the first reducer is connected to the motor shaft of the first drive motor, and the first drive head is connected to the output shaft of the first reducer, and is capable of clamping the first end of the mixing chamber; The second drive unit includes a second drive motor, a second reducer, and a second drive head. The second drive motor is connected to the frame and is spaced apart from the first drive motor in the X direction. The distance between the two drives is adjustable. The second reducer is connected to the motor shaft of the second drive motor, and the second drive head is connected to the output shaft of the second reducer. It is capable of clamping the second end of the mixing chamber. A control unit electrically connected to the first drive unit and the second drive unit to enable a controlled speed difference and / or steering difference during operation of the first drive unit and the second drive unit.

[0007] According to the technical solution provided by the present invention, the mixing chamber includes a main chamber body, multiple sample containers, and a filling and fixing component that enables the sample containers to remain stationary relative to the main chamber body, wherein the sample containers are sealed structures.

[0008] According to the technical solution provided by the present invention, the filling fastener is an elastic sponge block, a polymer foam material, or a modular bracket, which fills the gap between the inner wall of the main chamber and the outer wall of all the sample containers.

[0009] According to the technical solution provided by the present invention, the second drive motor is connected to the slide assembly, the slide assembly is fixedly connected to the frame, the slide assembly includes a guide rail, a slider slidably connected to the guide rail, and a locking member, the second drive motor is connected to the slider, and the locking member is used to lock the slider on the guide rail.

[0010] According to the technical solution provided by the present invention, the axis of the mixing chamber is set at an angle α in the X direction, where 30°≤α≤60°.

[0011] According to the technical solution provided by the present invention, the first end of the mixing chamber has a first drive journal that can be connected to the first drive head on its peripheral wall, and the second end has a second drive journal that can be connected to the second drive head on its peripheral wall. The directions of the first drive journal, the second drive journal, and the axis of the mixing chamber are perpendicular to each other.

[0012] A second aspect of the present invention provides a method for mixing automotive catalytic converter powder, employing the high-efficiency mixing device for automotive catalytic converter powder as described above, comprising the following steps: S1. Place the powder to be mixed into the mixing chamber, connect the first end of the mixing chamber to the first drive head, adjust the first drive unit and the second drive unit to the first interval, connect the second end to the second drive head, and fix the second drive unit. S2. The control unit sets the device operating time and controls the first drive unit and the second drive unit to operate in a manner with a speed difference or a direction difference, so as to drive the powder to be mixed in the mixing chamber to perform three-dimensional motion. S3. The control unit controls the first drive unit and the second drive unit to stop moving and remove the mixed powder from the mixing chamber.

[0013] According to the technical solution provided by the present invention, in step S2, the first driving unit is controlled to run with a first speed function ω1(t), and the second driving unit is controlled to run with a second speed function ω2(t), and ω1(t)≠ω2(t).

[0014] According to the technical solution provided by the present invention, the first velocity function ω1(t) and the second velocity function ω2(t) are generated based on a pseudo-random sequence so that the motion of the hybrid cabin is in a chaotic state.

[0015] According to the technical solution provided by the present invention, step S3 further includes determining whether the mixed powder meets the target parameters; if not, repeating steps S1 and S2. The target parameters include at least powder particle size and weight.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: The present invention sets up a first driving unit and a second driving unit to drive the mixing chamber simultaneously, and realizes differential rotation or reverse rotation between the first driving unit and the second driving unit through a controller, thereby forming a dynamic vortex field without dead angles in the chamber, forcing powder particles to generate high-frequency collisions and diffusion, and achieving efficient mixing. Attached Figure Description

[0017] Other features, objects, and advantages of the invention will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings: Figure 1 This is a schematic diagram of a vehicle catalyst powder mixing device provided in an embodiment.

[0018] Reference numerals: 1. Rack; 2. Mixing compartment; 3. First drive unit; 31. First drive motor; 32. First drive head; 4. Second drive unit; 41. Second drive motor; 42. Second drive head. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] This invention provides a powder mixing device for automotive catalysts, comprising a frame 1, a mixing chamber 2, a first drive unit 3, a second drive unit 4, and a control unit. The mixing chamber 2 is connected to the frame 1 and is used to hold the powder to be mixed.

[0022] The first drive unit 3 includes a first drive motor 31, a first reducer, and a first drive head 32. The first drive motor 31 is connected to the frame 1, the first reducer is connected to the motor shaft of the first drive motor 31, and the first drive head 32 is connected to the output shaft of the first reducer, capable of clamping the first end of the mixing chamber 2. In this embodiment, the first drive motor 31 is an AC servo motor, which is rigidly fixed to the frame 1 by a motor mount. The first reducer is a precision planetary reducer, whose input end is directly connected to the output shaft of the motor through a coupling to provide a stable output with high torque and low speed. The first drive head 32 is a gripper, fixedly mounted on the output shaft of the first reducer, and drives the mixing chamber 2 to rotate by bolt connection.

[0023] The second drive unit 4 includes a second drive motor 41, a second reducer, and a second drive head 42. The second drive motor 41 is connected to the frame 1 and is spaced apart from the first drive motor 31 along the X direction, with the spacing adjustable. The second reducer is connected to the motor shaft of the second drive motor 41, and the second drive head 42 is connected to the output shaft of the second reducer, capable of clamping the second end of the mixing chamber 2. In this embodiment, the second drive motor 41 is also an AC servo motor, and the second reducer is a precision planetary reducer, whose input end is directly connected to the output shaft of the motor via a coupling to provide a stable output with high torque and low speed. The second drive head 42 is a gripper, fixedly mounted on the output shaft of the second reducer, and drives the mixing chamber 2 to rotate by bolt connection.

[0024] Unlike the first drive unit 3, the second drive motor 41 is connected to the slide assembly, which is fixedly connected to the frame 1. The slide assembly includes a guide rail, a slider slidably connected to the guide rail, and a locking element. The second drive motor 41 is connected to the slider, and the locking element is used to lock the slider onto the guide rail. The entire second drive unit 4 can be smoothly slid along the guide rail in the X direction by manual pushing or with the aid of a simple auxiliary mechanism, thereby flexibly adjusting its center distance from the first drive unit 3. Once the position is adjusted, the locking element securely locks the slider onto the guide rail, ensuring rigidity during operation. This design makes loading mixing chambers of different lengths or performing equipment maintenance extremely convenient.

[0025] The control unit is electrically connected to the first drive unit 3 and the second drive unit 4 to ensure a controlled speed difference and / or steering difference during operation. The control unit is integrated into a separate control cabinet, and its core is a programmable logic controller (PLC). It is connected to the drivers of the first and second drive motors via cables. A touchscreen is provided on the control cabinet panel as the human-machine interface. An "asynchronous drive mode" is executed. In this mode, the controller sends independent and real-time varying speed commands ω1(t) and ω2(t) to the first drive motor 31 and the second drive motor 41, ensuring that ω1(t) ≠ ω2(t) during operation. The speed commands can fluctuate around a base value (e.g., 300 RPM) with different amplitudes, phases, or following a pseudo-random sequence. This controlled speed difference is the root cause of the three-dimensional chaotic motion generated by the driving hybrid chamber.

[0026] The present invention sets up a first driving unit 3 and a second driving unit 4 to drive the mixing chamber 2 simultaneously, and realizes differential rotation or reverse rotation between the first driving unit 3 and the second driving unit 4 through a controller, thereby forming a dynamic vortex field without dead angles in the chamber, forcing powder particles to generate high-frequency collisions and diffusion, and achieving efficient mixing.

[0027] The mixing chamber 1 includes a main chamber, multiple sample containers, and a filling and fixing component that keeps the sample containers stationary relative to the main chamber. In this embodiment, the main chamber is cylindrical, with end plates welded to both ends. At the center of each end plate, a first drive journal and a second drive journal are coaxially fixed, respectively. The two journals are precision-machined to have high coaxiality, with their axes perpendicular to the cylindrical axis of the main chamber. Through holes are machined on the two journals to allow for torque transmission without relative slippage after connection with the first and second drive heads. In this embodiment, the entire mixing chamber 1 (i.e., the axis of the main chamber) is set at a fixed tilt angle α with the X-direction after installation, 30°≤α≤60°. This tilted installation helps introduce richer variations in the gravitational component during three-dimensional motion, promoting axial flow of the powder.

[0028] To prevent cross-contamination and facilitate batch processing, the main chamber has an openable, sealed door (not shown in the figure) on one side, which can accommodate multiple independent sample containers. Each sample container is made of stainless steel and equipped with a threaded cap with a sealing ring to ensure its own airtightness. When mixing is required, the sample containers, each containing powder, are placed into the main chamber. Then, a filling fastener is used to tightly fill the gaps between all the sample containers and the inner wall of the main chamber. In this embodiment, the filling fastener is a sponge; the elastic pressure of the sponge firmly fixes all the sample containers, forming a unified whole with no relative movement to the main chamber. This allows multiple samples to be processed simultaneously in the same mixing field while remaining absolutely isolated from each other, and cleaning only requires processing individual sample containers, leaving the inner cavity of the main chamber virtually uncontaminated.

[0029] This embodiment also provides a method for mixing automotive catalytic converter powder, using the automotive catalytic converter powder mixing device described above, and the main steps include: S1. Place the powder to be mixed in the mixing chamber, connect the first end of the mixing chamber to the first drive head, adjust the first drive unit and the second drive unit to the first interval, connect the second end to the second drive head, and fix the second drive unit. S2. By controlling the control unit, the device running time is set, and the first drive unit and the second drive unit are controlled to operate in a manner with a speed difference or a direction difference, so as to drive the powder to be mixed in the mixing chamber to perform three-dimensional motion. S3. The control unit controls the first drive unit and the second drive unit to stop moving and remove the mixed powder from the mixing chamber.

[0030] In step S2, the control unit has a pre-stored experience database. The operator inputs basic powder information, such as the average particle size range (e.g., <38μm, 38-75μm, >75μm) and total loading mass. The control unit automatically recommends and sets a set of optimized operating parameters based on the input information, including runtime T, base rotation speed N_base, and speed difference amplitude ΔN. For example, for fine powder (<38μm), the system might recommend "T=7 minutes, N_base=280 RPM, ΔN=±20 RPM, mode=low-frequency random disturbance" to prevent excessive powder agitation. After user confirmation, the system starts with a single button press. The first and second drive units enter asynchronous drive mode under the control of the controller. Since ω1(t) ≠ ω2(t), and both ends of the mixing chamber are rigidly driven, according to rigid body kinematics, the entire mixing chamber is forced into a three-dimensional motion state. This motion is chaotic and non-periodic, far superior to simple rotation or fixed-track swaying. Under this intense three-dimensional chaotic tumbling action, the powder inside each individual sample container experiences an inertial force field with constantly changing direction and size, resulting in violent collisions, diffusion, and shearing between particles, leading to extremely high mixing efficiency. After mixing, the equipment stops. The user can remove a sample container for rapid pre-inspection. If the uniformity does not meet the preset target parameters (powder particle size and weight), the sample container can be returned, the parameters adjusted appropriately, and then a second round of supplementary mixing can be initiated. This feedback-based iterative optimization ensures stable and optimal mixing results even when powder properties fluctuate. After confirming that the mixing meets the standards, the main chamber is removed, and each individual sample container is taken out. These are directly sent to the testing station for sampling and analysis; due to the physical isolation between samples, there is no risk of cross-contamination. After use, only individual sample containers need to be cleaned, making maintenance simple.

[0031] Furthermore, although the steps of the method in this invention are described in a specific order in the accompanying drawings, this does not require or imply that the steps must be performed in that specific order, or that all the steps shown must be performed to achieve the desired result. Additionally or alternatively, certain steps may be omitted, multiple steps may be combined into one step, and / or one step may be broken down into multiple steps.

[0032] Through the above description of the embodiments, those skilled in the art will readily understand that the exemplary embodiments described herein can be implemented by software or by combining software with necessary hardware.

[0033] The above description is merely a preferred embodiment of the present invention and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention is not limited to the specific combination of the above-described technical features, but also includes other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above-described features with (but not limited to) technical features with similar functions disclosed in this invention.

Claims

1. A device for mixing automotive catalytic converter powder, characterized in that, include: A frame (1) is provided, on which a mixing chamber (2) is connected, the mixing chamber (2) being used to hold powder to be mixed. The first drive unit (3) includes a first drive motor (31), a first reducer and a first drive head (32). The first drive motor (31) is connected to the frame (1), the first reducer is connected to the motor shaft of the first drive motor (31), and the first drive head (32) is connected to the output shaft of the first reducer, and can clamp the first end of the mixing chamber (2). The second drive unit (4) includes a second drive motor (41), a second reducer, and a second drive head (42). The second drive motor (41) is connected to the frame (1) and is spaced apart from the first drive motor (31) in the X direction. The distance between them is adjustable. The second reducer is connected to the motor shaft of the second drive motor (41), and the second drive head (42) is connected to the output shaft of the second reducer. It can clamp the second end of the mixing chamber (2). A control unit electrically connected to the first drive unit (3) and the second drive unit (4) to provide a controlled speed difference and / or steering difference during operation of the first drive unit (3) and the second drive unit (4).

2. The automotive catalytic converter powder mixing device according to claim 1, characterized in that, The mixing chamber (1) includes a main chamber, multiple sample containers, and a filling fixture that enables the sample containers to remain stationary relative to the main chamber. The sample containers are sealed structures.

3. The automotive catalytic converter powder mixing device according to claim 2, characterized in that, The filling fastener is an elastic sponge block, a polymer foam material, or a modular bracket, which fills the gap between the inner wall of the main chamber and the outer wall of all the sample containers.

4. The automotive catalytic converter powder mixing device according to claim 1, characterized in that, The second drive motor (41) is connected to the slide assembly, which is fixedly connected to the frame (1). The slide assembly includes a guide rail, a slider slidably connected to the guide rail, and a locking member. The second drive motor (41) is connected to the slider, and the locking member is used to lock the slider on the guide rail.

5. The automotive catalytic converter powder mixing device according to claim 1, characterized in that, The axis of the mixing chamber (2) is set at an angle α in the X direction, where 30°≤α≤60°.

6. The vehicle catalytic converter powder mixing device according to any one of claims 1-5, characterized in that, The first end of the mixing chamber (2) has a first drive journal on its peripheral wall that can be connected to the first drive head (32), and the second end has a second drive journal on its peripheral wall that can be connected to the second drive head (42). The directions of the first drive journal, the second drive journal, and the axis of the mixing chamber (2) are perpendicular to each other.

7. A method for mixing automotive catalytic converter powder, characterized in that, The high-efficiency mixing device for automotive catalytic converter powder as described in any one of claims 1-6 includes the following steps: S1. Place the powder to be mixed in the mixing chamber (2), connect the first end of the mixing chamber (2) to the first drive head (32), adjust the first drive unit (3) and the second drive unit (4) to the first interval, connect the second end to the second drive head (42), and fix the second drive unit (4). S2. The device running time is set by the control unit, and the first drive unit (3) and the second drive unit (4) are controlled to operate in a manner with a speed difference or a steering difference, so as to drive the powder to be mixed in the mixing chamber (2) to perform three-dimensional motion. S3. The control unit controls the first drive unit (3) and the second drive unit (4) to stop moving and remove the mixed powder from the mixing chamber (2).

8. The method for mixing automotive catalytic converter powder according to claim 7, characterized in that, In step S2, the first driving unit is controlled to run with a first speed function ω1(t), and the second driving unit is controlled to run with a second speed function ω2(t), and ω1(t)≠ω2(t).

9. The method for mixing automotive catalytic converter powder according to claim 8, characterized in that, The first velocity function ω1(t) and the second velocity function ω2(t) are generated based on a pseudo-random sequence to make the motion of the hybrid cabin (2) chaotic.

10. The method for mixing automotive catalytic converter powder according to claim 7, characterized in that, Step S3 further includes determining whether the mixed powder meets the target parameters; if not, repeating steps S1 and S2. The target parameters include at least powder particle size and weight.

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