Push Rod Research Articles

Simulation and Analysis of Double Compound CAM Pusher Tool Changing Mechanism for NC Machine Tool

The core mechanism of existing CNC tool changers is typically a single composite cam swinging rod linkage. This setup has two main drawbacks: amplified vibration errors and high impact forces due to the swinging rod. To address these, this study focuses on CNC tool changers, specifically selecting the up-and-down motion follower and proposing a novel double composite cam push rod type mechanism. Solid modeling for both mechanisms was conducted using Creo and Matlab, and theoretical modeling of the contact forces for each follower type was completed. Comparative analysis shows the push rod follower exhibits lower contact forces than the swinging rod. Using the Adams platform, the dynamic characteristics of both mechanisms were analyzed, leading to an optimized design for the push rod type. An experimental model, scaled to 0.5, was built to compare experimental data with simulation results. The findings verify the accuracy of the models, supporting the feasibility of the push rod type tool changer.

Self-powered human movement measurement with a unidirectional ratchet driven wearable energy harvester

A large amount of energy is generated during human movement which is mostly not effectively utilized. To collect human movement energy and utilize it rationally, a wearable piezoelectric-electromagnetic energy harvester (WPEEH) driven by a unidirectional ratchet is proposed, which adopts the principle of up-conversion to convert mechanical energy into electrical energy. The electromagnetic power generator unit is used to obtain energy to power the sensing circuit, while piezoelectric generator unit can be used for both energy generation and self-powered sensing. A spring push rod and a ratchet structure are used to convert the swinging of the human limb into the unidirectional rotation of the device to enhance its energy harvesting efficiency. The theoretical model of the WPEEH is established, and the experimental test platform is built. The results show that the WPEEH is able to generate a maximum power of 17.2 mW at an oscillation frequency of 1.5 Hz. In the actual wearable test, the proposed energy harvester is able to supply the harvested energy to the low-power electronic devices through capacitors, and it enables to light up 42 LEDs as well as to drive the digital thermo-hygrometer to work continuously and stably. Apart from having excellent properties of a high output power and low drive frequency, the proposed energy harvester also exhibits a high energy density (7.1 × 10–5 W/cm3). What’s more, the speed of human movement can be predicted and calculated for different individuals by testing the results of the swing frequency with a maximum error of 2.71 %. The investigation proves that the proposed WPEEH can measure human movement and has great potential in the field of power supply for low-power electronic devices.

Precision encoder grating mounting: a near-sensor computing approach.

The rotary motor plays a pivotal role in various motion execution mechanisms. However, an inherent issue arises during the initial installation of the encoder grating, namely, eccentricity between the centers of the encoder grating and motor shaft. This eccentricity substantially affects the accuracy of motor angle measurements. To address this challenge, we proposed a precision encoder grating mounting system that automates the encoder grating mounting process. The proposed system mainly comprises a near-sensor detector and a push rod. With the use of a near-sensor approach, the detector captures rotating encoder grating images, and the eccentricity is computed in real-time. This approach substantially reduces the time delays in image data transmission, thereby enhancing the speed and accuracy of eccentricity calculation. The major contribution of this article is a method for real-time eccentricity calculation that leverages an edge processor within the detector and an edge-vision baseline detection algorithm. This method enables real-time determination of the eccentricity and eccentricity angle of the encoder grating. Leveraging the obtained eccentricity and eccentricity angle data, the position of the encoder grating can be automatically adjusted by the push rod. In the experimental results, the detector can obtain the eccentricity and eccentricity angle of the encoder grating within 2.8 s. The system efficiently and precisely completes a encoder grating mounting task in average 25.1 s, and the average eccentricity after encoder grating mounting is 3.8 µm.

Customizable Push Rod for Forsus Appliance

Introduction Among fixed orthodontic appliances, Forsus fatigue-resistant device (FRD) is a popular choice for treating Class II malocclusion in permanent dentition due to its patient-friendly design. FRD utilizes nickel titanium coil springs to deliver precise and adjustable forces for clinical applications. Material and method A 16 gauge stainless steel wire is used for the fabrication of push rods. Results The fabricated push rods work with efficacy in advancing the mandible in forward position. Conclusion In cases of push rod size mismatch our innovative design overcomes these limitations, ensuring optimal fit and performance.

Development of a Test Tube Automatic Sorting Storage Device After Completion of Inspection.

To develop an automatic test tube classification and storage device that sorts test tube boxes by detecting the box height and test tube cap color, improving laboratory efficiency and accuracy. An upper computer uses a No. 1 push rod to allocate test tube boxes to specific branch conveyor belts based on initial sorting criteria. Further sorting is done by the No. 2 push rod, which places boxes into adjustable slots within a seven-layer elevating storage system, categorizing them by day through height adjustment to match the conveyor belt. This invention automates test tube sorting and storage, aiding medical staff in quickly and accurately locating test tubes post-inspection.

Design Method of Cam Steering Mechanism Based on Path Fitting

In order to improve the accuracy of a solar-powered punch card car’s movement on a designated route and reduce positional deviations during its operation, a solar-powered punch card car with a single cam as the steering guidance mechanism was designed. The car adopts a three-wheel structure. The transmission mechanism, steering mechanism, driving mechanism, and regulating mechanism of the car were analyzed. The kinematics model of the car was established and the motion characteristics of the car were obtained. By analyzing the relationship between the steering angle of the car and the curvature radius of its travel route, the front wheel angle of the car at each position was calculated using MATLAB R2020a. This allowed us to establish the relationship between the front wheel angle and the displacement of the steering push rod, which was further converted into the theoretical contour line of the cam. Subsequently, the theoretical contour line of the cam was completed and envelope correction was performed. Finally, through mechanical analysis and experimental verification using a prototype, the results indicated that the single-cam steering guidance mechanism calculated using this fast path fitting method exhibited excellent mechanical performance and a smooth and accurate trajectory, and the traveling path of the theoretical cam contour curve was basically consistent with the actual trajectory route.

The Use of Spiral Cement Injector for Percutaneous Vertebroplasty to Treat Kümmell Disease: A Retrospective Study

Percutaneous vertebroplasty (PVP) is a common method used to treat Kümmell disease. In patients without neurologic symptoms, we sought to evaluate whether using the new spiral injectors instead of the traditional push-rod injectors in PVP can result in improved clinical efficacy for the treatment of Kümmell disease. A clinical retrospective study was conducted between August 2018 and December 2020. The study included patients diagnosed with single-level thoracolumbar Kümmell disease who underwent PVP surgery. The patients were divided into 2 groups: an observation group consisting of 53 patients treated with spiral injectors and a control group consisting of 68 patients treated with push-rod injectors. A 2-year follow-up period was adopted. The bone cement injection volume and occurrence of bone cement leakage were significantly greater in the observation group compared with the control group (P < 0.05). The observation group had significantly shorter operation time and intraoperative fluoroscopy times compared with the control group (P < 0.05). The scores for the visual analog scale and Oswestry Disability Index in both groups were significantly lower at 3 days or 3 months and 2 years after surgery compared with before surgery, with the scores at 2 years after surgery being significantly lower than those at 3 days or 3 months for both groups (P < 0.05). The relative anterior ledge height and Cobb angle showed significant improvement at 3 days and 2 years after surgery compared with before surgery in both groups (P < 0.05), but patients in the observation group experienced substantial improvement at 3 days and 2 years after surgery compared with those in the control group (P < 0.05). In both groups, the relative anterior ledge height was noticeably lower 2 years after surgery compared with 3 days after surgery (P < 0.05). Concurrently, there was a significant increase in the local Cobb angle over time in both groups (P < 0.05). The implementation of both spiral injectors and traditional push-rod injectors in PVP surgery yields effective pain relief, improved function, partially restored vertebral height, and corrected kyphosis in treating Kümmell disease. Compared with the push-rod injector, the spiral injector is highly efficient in restoring vertebral height, correcting kyphosis, and minimizing fluoroscopy use and operation time, but it carries a greater risk of bone cement leakage.

Application of Control Algorithm in the Design of Automatic Crimping Device for Connecting Pipe and Ground Wire

Due to the low effectiveness and poor quality of manual crimping of grounding wires, the author proposes the design of an automatic crimping device for connecting tube grounding wires based on intelligent fully automatic technology. The device consists of a microcontroller, an upper computer control interface, an electric push rod, an infrared sensor, a pressure transmitter, and other devices. The staff used the upper computer monitoring interface to set the relevant parameters for grounding wire crimping, and used X-ray digital imaging technology to measure the crimping size of the grounding wire. The size met the set parameter conditions. Through the PID control algorithm in the microcontroller, the stepper motor was controlled to push the clamp to move, completing the automatic crimping of the grounding wire. The X-ray detection method was introduced to detect the quality of the grounding wire after the crimping was completed. The experimental results show that the average deviation between the measured crimping size of the grounding wire and the actual measurement size by the automatic crimping device is only 0.06 mm, indicating that its measurement results are accurate; The success rate of crimping exceeds 95%. The above experimental results verify that the designed crimping device has high stability and reliability, and good quality detection effect.

A Diagnostic Machine Learning Algorithm for Air Brakes in Commercial Vehicles⁎

To safely introduce any level of autonomy to trucks, the health of their brake systems needs to be monitored continuously. Out-of-adjustment push rods and leakages in the air brake system are two major reasons for increased braking distances in trucks, and result in safety violations. Air leakages can occur due to small cracks or loose/improperly ft couplings which do not affect the overall braking capacity but contribute greatly to increasing the braking lag and reducing the maximum braking torque at the wheels. Similarly, an increased stroke of push rod leads to a larger delay in brake response and a smaller value of the brake torque at the wheels. Currently, the condition of an air brake system is inspected manually by measuring the push rod offset, checking the couplings and hoses of the system for air leakages. These inspections are highly labor intensive, subjective, time consuming and do not accurately quantify how adversely the braking system is affected. Having an on-board diagnostic device that can monitor the health of air brakes would be crucial in the prevention of road accidents, especially when considering any level of automation and comply with FMSCA safety requirements. The focus of this paper is to aid the development of such a diagnostic system that facilitates enforcement and pre-trip inspections and continuous on-board monitoring of trucks through the development of a model for its multi-chamber braking system; this model can be used to estimate the severity of leakage and the push rod stroke using real time brake pressure transients. A machine learning algorithm for estimating the air leakage in the air brake system and its experimental corroboration is presented in this paper.

Aerial Gaze Target Recognition Based on Head and Eye Movements

Aerial gaze target recognition is an important step in aerial eye control interaction. In order to achieve accurate aerial gaze target recognition, the VT4LM recognition algorithm was constructed in this paper. By this algorithm, the facial images containing the eyes of the flight operators were first inputted into Vision Transformer (ViT) to extract the local features, and the head posture of the flight operators was inputted into four LSTMs to extract the global features. Then, the local and global features of the flight operators were inputted into three fully connected layers, two dropout layers and one softmax classifier. Finally, the recognition result of aerial gaze target was obtained. In this paper the effectiveness of the VT4LM recognition algorithm was verified through the identification of four aerial line-of-sight gaze targets named Head-up display, Accelerator push rod, Control lever and Rudder by four flight operators during simulated flight. The experimental results showed that the accuracy of the VT4LM algorithm for aerial gaze target recognition reached 89.29% and the Cross Entropy Loss was 1.45. Compared to the other three recognition methods, the VT4LM algorithm had the highest recognition accuracy and minimum loss. When using the VT4LM algorithm to detect four simulated flight operators staring at four aerial gaze targets, the recognition accuracy was all higher than 85.00%. It could be seen that the VT4LM algorithm had a good performance in aerial gaze target recognition.

Design and Experimental Testing of an Overhead Rail Automatic Variable-Distance Targeted Spray System for Solar Greenhouses

Crop cultivation in solar greenhouses is affected by issues such as low levels of automation in spraying machinery, inefficient spraying, and a lack of suitable spraying equipment for vertically cultivated crops, all of which are in urgent need of resolution. To address these problems, this paper proposes a suspended-rail automatic variable-distance targeted spray system. The rated working speed of the spray system is 0.3 m/s, and the rated working pressure is 0.3 MPa. This system achieves precise spraying of crops at varying heights by dynamically adjusting the position of the spray nozzle. To ensure accuracy in spraying, the system employs a laser ranging sensor for real-time measurement of crop positions and spraying distances. Combined with a parameter processing scheme, the system generates control signals to adjust the operation of the electric push rod and electromagnetic valve, thereby dynamically adjusting the spraying distance and timing. Using vertically cultivated potted peppers as experimental subjects, this study compares the performance of fixed- and variable-distance spraying modes. The results indicate that, compared to the fixed-distance mode, the automatic variable-distance mode increases pesticide adherence by 16.65% and reduces pesticide usage by 29.58%. The proposed suspended-rail automatic variable-distance targeted spray system offers an effective technical solution for the precise spraying of vertically cultivated crops in solar greenhouses and thus contributes to improved pesticide utilization efficiency, reduced pesticide residue, and lower environmental pollution.

基于 Arduino 的小型蔬菜播种机远程控制系统设计与性能试验

Facilities greenhouses are relatively narrow and airtight, and the machine operation turns frequently. The existing vegetable seeders is supported by manual hand, and the straightness of operation is poor, Turning around is time-consuming and laborious. This paper designs a remote control system of small vegetable seeder based on Arduino microcontroller, the Arduino single-chip microcomputer remote control technology, multi-motor synchronous drive technology, differential-electric push rod combined with lifting and steering control and other methods are adopted, Through remote control, the forward, speed regulation, lifting of the whole machine and field line change and steering of the seeder during vegetable sowing are realized. The differential steering model and brushless motor speed control model are established, and the android human-computer interaction APP is designed to realize the remote precise control of vegetable seeder. The performance test of the accuracy of the control system was carried out with the accuracy and steering accuracy of the seeder. The results showed that : under the condition of medium speed and medium and low speed operation, the seeding level of vegetable seeder is the most stable and reliable, the speed deviation rate of the seeder is 1.59 %, after starting the drive motor for 2s, the actual speed is close to the target speed, differential steering is relatively accurate, the qualified rate of steering is more than 89.8 %, the synchronous speed error of the lifting mechanism tends to be stable.This study can provide reference for the development of intelligent equipment for facility agriculture.

The Teaching Application of the Backward Design Method in Chinese National Undergraduate Engineering Training Integration Ability Competition: Take the Double 8 Carbon-Free Car as an Example

National Undergraduate Engineering Training Integration Ability Competition is essential in Chinese engineering colleges. Among these items, the carbon-free car competition is popular among college students because of its flexible track, challenging design tasks, and fair judging criteria. In this study, to design a reasonable carbon-free car structure according to the track given by the competition, a reverse analysis method was proposed for the double 8-shaped carbon-free car trajectory based on the space cam mechanism. First, the carbon-free car’s structure was designed, and its stress state was analyzed, with the results indicating that the driving force should be reduced as much as possible under the premise of satisfying the starting requirements to increase the travel distance of the carbon-free car with no slipping. Then, the function between the car track and the front wheel swing angle was established, and the displacement law of the push rod of the cam mechanism was calculated through the swing angle of the front wheel. Finally, the cam profile was got based on the operating law of the push rod. Research has shown that compared with the traditional forward design, this method was more accurate with strong feasibility and operability, which provided good technical support for designing the subsequent carbon-free car competition.

Design and dry wind tunnel test of progressive flexible variable bending wing

AbstractThe deformable wing structure can change its aerodynamic shape according to the change of flight mission and flight environment, so as to obtain better lift-drag, stability and control characteristics, which is considered as one of the future research directions of aviation technology. Considering the current technology maturity and reliability, a gradient corrugated fin is designed to realise the bending deformation of the wing. The structure of the skin is optimised to keep the skin smooth during deformation. In addition, a progressive push and pull rod is proposed to drive the wing deformation, and the fluid-structure interaction simulation is carried out for the wing deformation. At the same time, the changes of wing aerodynamic characteristics under different angles of leading and trailing edges and different push rod action schemes are analysed. Finally, a dry wind tunnel simulation test of the designed progressive flexible variable bending wing is carried out. The results of fluid-structure interaction simulation and dry wind tunnel test show that the progressive flexible variable bending wing proposed in this paper has a simple and reliable structure and remarkable deformation effect. It has advantages in increasing lift and reducing drag, ensuring high lift-drag ratio and providing wing trim moment. The deformable wing dry wind tunnel test platform designed by this method is structurally reliable, easy to operate, and can accurately reflect the influence of wing deformation on its aerodynamic force, which provides a verification means for the development of the design method and the design of practical aircraft in the future.

Reduction in Total Production Cycle Time by the Tool Holder for the Automated Cutting Insert Quick Exchange and by the Double Cutting Tool Holder

The time taken to exchange a cutting tool and the actual machining time are the components in a total production cycle time for a part, that affects productivity. Automated plate exchange systems strive for the simplest possible principles to achieve the shortest possible tool exchange time with sufficient accuracy. The tool holder in the presented article is based on the principle of a combination of translational, rotational movement, and stop surfaces by using a single pull–push rod for simple control. The article provides alternative tool holder designs and turning results of such holders using Rz-f dependence. The results of the time reduction are satisfactory and give a prerequisite for using a tool holder for the automated exchange of triangular cutting inserts. Moreover, the article provides the approach to reduce the mentioned total production cycle time by a reduction in the actual machining time for a part by use of tooltip radii, not by increasing the cutting speed. The triangular cutting insert can have three tooltips of three different tooltip radii for roughing and finishing. In addition, for reduction of the actual machining time, the double cutting tool with both the small tooltip radius for rouging and the large tooltip radius for finishing is presented. The double tool holders showed a 2.4-times reduction in the actual machining time for a part with Rz = 20 µm.

Dynamics Analysis of the Double Push Rod Limb-Leg Mechanism with Clearance Joint

Dynamics Analysis of the Double Push Rod Limb-Leg Mechanism with Clearance Joint

Coatings protecting against aviation piston engine seizure

The article presents the basics of manufacturing porous (16%) composite coatings based on phenolic resin reinforced with glassy carbon particles (30 wt%). These coatings, when applied to a steel push rod surface, prepared by sandblasting, of the timing system of an aircraft piston internal combustion engine, prevent seizure of the contact in conditions of lubrication failure up to 10 h (μ≈0.1 by p = 8 MPa, v = 0.5 m/s), extending the last stage of flight time of the aircraft. The reference coating undergone seizure, μ> 1 after 5 h. The conditions and results of laboratory tests on a pin-on-disc tribological tester and tests on an engine test bench are described. The dependencies of the coefficient of friction and wear of the push rod on the glassy carbon content, thinner viscosity and sandblasting pressure, described by the equations of the second degree, allowed the optimal conditions to be determined to the produce coatings. The test results of the developed composite porous coatings were compared with the results of non-porous commercial coatings. The wear of developed coating compared to reference one and matrix coatings was respectively ΔmCC = −1.63 mg (mass increase), ΔmRC = 1.3 mg and ΔmMC = 5.56 mg.

Design and Dynamic Characteristics Analysis of Novel Support Adjustment Mechanism of Wheeled Downhole Tractor

Conventional design method of the downhole tractor is based on cementing casing, which is only suitable for the smooth wellbore. For the open hole well, the conventional downhole tractor has poor adaptability and even cannot work normally. In order to improve the obstacle surmounting performance of the wheeled downhole tractor (WDR) and expand the application range of the WDR, a double push rod-double spring support adjustment mechanism (DPRDSSAM) is proposed in this paper. Meanwhile, the proposed DPRDSSAM also needs to increase the traction force and the stability of the WDR in the open hole well. Kinematic simulation numerical models of both conventional support adjustment mechanism and the DPRDSSAM are established. The two models comprehensively considere the influence of different obstacle forms and sizes on the obstacle surmounting performance of the tractor. The influence of different obstacle forms on the obstacle surmounting performance of DPRDSSAM and single push rod support adjustment mechanism (SPRSAM) is analyzed. Results show that the DPRDSSAM has better obstacle surmounting performance than the SPRSAM. The DPRDSSAM can effectively promote further research and application of the tractor in the open hole well.

Effects of particle size in silica sol on the mechanical and thermal properties of SiO2f/SiO2 composites

AbstractIn this paper, quartz fiber‐reinforced silica matrix SiO2f/SiO2 composites were prepared by the precursor impregnation‐heat treatment method using quartz fiber needle felt as the reinforcement and silica sol as the precursor. The effects of particle size in silica sol (10, 50, and 100 nm) on the density, apparent porosity, mechanical properties, and thermal properties of SiO2f/SiO2 composites were investigated. The phase composition and microstructure of the composites were characterized by X‐ray diffraction and scanning electron microscopy, respectively. The thermal expansion coefficient and thermal conductivity of composites were measured by a push rod method and the laser method. The results show that the density, apparent porosity, and mechanical strength of the specimens firstly increase and then decrease with the increase in the particle size in silica sol. The sample using silica sol with particle size 50 nm has the optimum overall performances (i.e., the flexural strength of 13.7 MPa and the compressive strength of 59.8 MPa), and shows a ductile fracture behavior. At 300°C–700°C, the average thermal expansion coefficient of the optimal sample is .783 × 10−6/°C. And the thermal conductivity of the samples increases with the increase in temperature, and it reached the highest value of .810 W/(m·K) at 700°C. The SiO2f/SiO2 composites show obvious advantages in the application of load‐bearing and thermal insulation integration, and they are expected to meet the demanding requirements of hot‐pressing sintering and non‐ferrous metallurgy industries.

Modeling and driving function optimization of tree climbing robot

To ensure the tree-climbing robot can complete the up-tree or down-tree process, its arms need to adjust the displacement of the push rod in real-time according to the diameter size of the tree trunk so that the tire can smoothly bypass the smaller tree pile. However, the irregular shape of the trunk surface makes the inflatable tire vibrate during rolling, which will reversely affect the performance of the push rod. Based on this, the three-dimensional model of the tree-climbing robot is established by Solid Works software, and the kinematics simulation model of the tree-climbing robot is established by Automatic Dynamic Analysis of Mechanical Systems (ADAMS). The kinematics simulation analysis is carried out. According to the tire displacement curve of the tree-climbing robot, the optimal solution of the push rod driving function is solved. Under the condition of ensuring the trajectory of the spiral rise is unchanged, the mean square deviation of the distance between the two arms of the tree-climbing robot is the smallest, and the push rod is the least affected by the reverse effect of the tire. The simulation results show that under the condition of the optimal solution, the frequency distribution and amplitude of the four springs are basically the same. The force of the four springs is uniform, and the reverse influence of the tires on the two push rods is minimized, which is conducive to the improvement of the stability of the tree climbing robot.