A modified trapezoid acceleration pattern with a constant speed part is introduced for loomrapier motion driven by cam.The pattern can meet the time requirement of rapier on entering andleaving the shed,and can satisf...A modified trapezoid acceleration pattern with a constant speed part is introduced for loomrapier motion driven by cam.The pattern can meet the time requirement of rapier on entering andleaving the shed,and can satisfy the condition when the period duration of inserting is not equal tothat of withdrawing.Meanwhile,the pattern can also reduce the maximum acceleration of rapierand make the derivatives of rapier acceleration change continuously without any abruptness ofjerks.展开更多
On the basis of the analysis of typical orthogonal crankrocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are stu...On the basis of the analysis of typical orthogonal crankrocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are studied when the maximum swing angle of rocking lever and the length of outputting lever have different values, and the optimum parameters suitable for motion transmission can be chosen. At the same time some existing shortpoints of the mechanism are also pointed out.展开更多
A new type of rapier drive for flexible rapier loom through conjugate cams with five-bar linkage mechanism is raised and analyzed. Two designs suitable for the conversion of 1515-190.5 shuttle looms are given as examp...A new type of rapier drive for flexible rapier loom through conjugate cams with five-bar linkage mechanism is raised and analyzed. Two designs suitable for the conversion of 1515-190.5 shuttle looms are given as examples. This mechanism can be applied to traditional shuttle looms as well as to new flexible rapier loom design.展开更多
In this paper,the effects of loom speed fluctuation on the mean speed and on the power ofdriving motor were investigated and the expressions for these effects were derived.Based on theenergy relationships,a new index ...In this paper,the effects of loom speed fluctuation on the mean speed and on the power ofdriving motor were investigated and the expressions for these effects were derived.Based on theenergy relationships,a new index of equivalent fluctuation was introduced,the connection be-tween this equivalent fluctuation and the energy of speed function on frequency domain was thenfound.In addition to the above theme,the residual kinetic energy of the shuttle and pickingmechanism,taken as a considerable part in the potentiality of loom energy-saving was also ana-lysed.According to the results of theoretical analyses,the ways of energy-saving in looms weresuggested.Finally,taking the loom of 1511 type as a practical example,the potentiality ofenergy-saving was calculated.展开更多
Based on the requirements of the two-phase rapier loom’s beat-up system characteristics, the dynamic responses of its beat-up system to three different types of cam input motion are studied in this paper. Also, their...Based on the requirements of the two-phase rapier loom’s beat-up system characteristics, the dynamic responses of its beat-up system to three different types of cam input motion are studied in this paper. Also, their corresponding analytical comparisons are made. At the end of the paper, the authors put forward a proposal of new type cam beat-up motion for future practice.展开更多
Based on the analysis, according to the principle of vibration, of the working character of weft tension compensator in needle looms, the paper studied the principle of tension compensation and introduced the idea of ...Based on the analysis, according to the principle of vibration, of the working character of weft tension compensator in needle looms, the paper studied the principle of tension compensation and introduced the idea of compensating coefficient. The paper also discussed some factors affecting the effect of tension compensation.展开更多
The axle-treadle mechanism of Han loom consists of a set of components, including two pedals controlling one shaft via a central axle. Based on the new archaeological finds, especially the pottery loom model, the coll...The axle-treadle mechanism of Han loom consists of a set of components, including two pedals controlling one shaft via a central axle. Based on the new archaeological finds, especially the pottery loom model, the collection of Krishna Riboud, and the historical document, a kind of axle treadle loom with oblique warp frame was reconstructed by author. It might be applied in the central China at that time, especially in Shandong and Jiangsu areas, and it was not later than the Warring State period for the oblique axle treadle loom to come into being and reach a peak in the Han Dynasty. After that time, it was used with the vertical frame but lost the importance gradually.展开更多
For a complicated high speed reciprocating machine to meet the requirements of precise motion of its mechanisms, a study of its kineto-elastodynamies is necessary. Here is an example to find out the cause of the misen...For a complicated high speed reciprocating machine to meet the requirements of precise motion of its mechanisms, a study of its kineto-elastodynamies is necessary. Here is an example to find out the cause of the misengagement of flexible rapiers, by means of kineto-elastodynamic analysis, so as to meet the requirements of flexible rapier loom′s design, with beat-up and weft insertion mechanisms operating at high speed.展开更多
In this paper, a review of the shuttleless looms’ development shows that three types of shuttleless looms: rapier, Jet and gripper projectile, are now equally matchable with each other. A prospect of the shuttleless ...In this paper, a review of the shuttleless looms’ development shows that three types of shuttleless looms: rapier, Jet and gripper projectile, are now equally matchable with each other. A prospect of the shuttleless loom’s development is also dealt with. It can be predicted that both rapier and Jet looms will be developed further and the future development of a new type of modern weaving looms will be prosperous in the coming 21st century.展开更多
On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be impr...On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be improved to raise the speed of water jet as well as weft insertion rate and to enlarge the width of woven fabrics a lot. At the same time it also points out that to increase water jet speed and to prolong its affective jet time depend mainly on the accretion of spring rate (constant)of stiffness and the diminution of plunger's cross sectional area respectively.展开更多
The motion laws for rapier weft insertion mechanism are analyzed. According to the special requirements on rapier loom's weft-insertion system for weaving three-dimensional( 3-D) fabric,a new rapier electronic wef...The motion laws for rapier weft insertion mechanism are analyzed. According to the special requirements on rapier loom's weft-insertion system for weaving three-dimensional( 3-D) fabric,a new rapier electronic weft-insertion system is presented. The design principle for 3-D loom's weft insertion system is introduced,including the design of the motion law of electronic weft-insertion system,the driving system's hardware configure,and its software's controlling principle. The weft insertion system is computer-controlled and servocylinder driven so as to control the rapier's movement to insert the weft into the multi-shed while 3-D weaving. This method greatly simplifies the weft-insertion system,achieves weft-insertion with variable travel,and improves the flexibility and reliability. The weft insertion system has been applied in a 3-D loom successfully.展开更多
The figure of shuttle distribution one side of the loom has been used to show the convel-sion of shuttle in picking process.The characteristics of the figure have been analysed andused to introduce a simple method for...The figure of shuttle distribution one side of the loom has been used to show the convel-sion of shuttle in picking process.The characteristics of the figure have been analysed andused to introduce a simple method for shuttle starting distribution.展开更多
Massive job losses are in the offing in the textile sector, says the theApparel Export Promotion Council (AEPC).The high prices of cotton have pushed up the cost of the fabric andthe end product. We are now in a situa...Massive job losses are in the offing in the textile sector, says the theApparel Export Promotion Council (AEPC).The high prices of cotton have pushed up the cost of the fabric andthe end product. We are now in a situation where we are forced to rejectrepeat orders as we can’t justify the high prices to our foreign buyers.展开更多
For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get...For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.展开更多
The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocit...The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.展开更多
Periodic variations of warp tension during a weaving cycle result in corresponding change of back rest position, and the oscillation of back rest affects the fluctuation of warp yarn in return. A mechanical model of b...Periodic variations of warp tension during a weaving cycle result in corresponding change of back rest position, and the oscillation of back rest affects the fluctuation of warp yarn in return. A mechanical model of back rest system of looms is presented on basis of auto control theory, and the factors affecting the dynamic performance of the back rest are analyzed. In the model, warp yarn is regarded as a viscoelastic medium, and the adjustable parameters and the adjusting range of the back rest system are increased, so the ioom's applicability for the fabric's variety is enlanced.Finally, the methods of designing and adjusting the back rest are discussed, and a trend of back rest system development is given.展开更多
The water jet impulse is brought forward to study the traction force of the water jet to the flying weft in water-jet looms. The distribution of the water jet impulse in the shed is tested by a sensor, and the influen...The water jet impulse is brought forward to study the traction force of the water jet to the flying weft in water-jet looms. The distribution of the water jet impulse in the shed is tested by a sensor, and the influence of water jet parameters on the water jet impulse is analyzed.展开更多
A kind of gold in-woven fabric of Korean Goryeo Dynasty was successfully replicated on a Chinese draw loom with a major pattern sheet in The Yunjin Research Institute, Nanjing city.
In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main...In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main effective approaches to increase the filling insertion rate and to widen the reed space of the loom are pointed out.展开更多
In order to study the propulsive force on the water-jet to the flying weft in water-jet looms, a dynamic model has been established. Based on the analysis and example testing, an experiential formula of the propulsive...In order to study the propulsive force on the water-jet to the flying weft in water-jet looms, a dynamic model has been established. Based on the analysis and example testing, an experiential formula of the propulsive force of the water-jet to the flying weft is obtained for the first time. The formula will profit the further research of the water-jet weft insertion and the production of textile.展开更多
文摘A modified trapezoid acceleration pattern with a constant speed part is introduced for loomrapier motion driven by cam.The pattern can meet the time requirement of rapier on entering andleaving the shed,and can satisfy the condition when the period duration of inserting is not equal tothat of withdrawing.Meanwhile,the pattern can also reduce the maximum acceleration of rapierand make the derivatives of rapier acceleration change continuously without any abruptness ofjerks.
文摘On the basis of the analysis of typical orthogonal crankrocking lever spatial mechanism for the weft insertion in rapier looms, the rules of the outputting lever motion and the mechanism pressure-angle variety are studied when the maximum swing angle of rocking lever and the length of outputting lever have different values, and the optimum parameters suitable for motion transmission can be chosen. At the same time some existing shortpoints of the mechanism are also pointed out.
文摘A new type of rapier drive for flexible rapier loom through conjugate cams with five-bar linkage mechanism is raised and analyzed. Two designs suitable for the conversion of 1515-190.5 shuttle looms are given as examples. This mechanism can be applied to traditional shuttle looms as well as to new flexible rapier loom design.
文摘In this paper,the effects of loom speed fluctuation on the mean speed and on the power ofdriving motor were investigated and the expressions for these effects were derived.Based on theenergy relationships,a new index of equivalent fluctuation was introduced,the connection be-tween this equivalent fluctuation and the energy of speed function on frequency domain was thenfound.In addition to the above theme,the residual kinetic energy of the shuttle and pickingmechanism,taken as a considerable part in the potentiality of loom energy-saving was also ana-lysed.According to the results of theoretical analyses,the ways of energy-saving in looms weresuggested.Finally,taking the loom of 1511 type as a practical example,the potentiality ofenergy-saving was calculated.
文摘Based on the requirements of the two-phase rapier loom’s beat-up system characteristics, the dynamic responses of its beat-up system to three different types of cam input motion are studied in this paper. Also, their corresponding analytical comparisons are made. At the end of the paper, the authors put forward a proposal of new type cam beat-up motion for future practice.
文摘Based on the analysis, according to the principle of vibration, of the working character of weft tension compensator in needle looms, the paper studied the principle of tension compensation and introduced the idea of compensating coefficient. The paper also discussed some factors affecting the effect of tension compensation.
文摘The axle-treadle mechanism of Han loom consists of a set of components, including two pedals controlling one shaft via a central axle. Based on the new archaeological finds, especially the pottery loom model, the collection of Krishna Riboud, and the historical document, a kind of axle treadle loom with oblique warp frame was reconstructed by author. It might be applied in the central China at that time, especially in Shandong and Jiangsu areas, and it was not later than the Warring State period for the oblique axle treadle loom to come into being and reach a peak in the Han Dynasty. After that time, it was used with the vertical frame but lost the importance gradually.
文摘For a complicated high speed reciprocating machine to meet the requirements of precise motion of its mechanisms, a study of its kineto-elastodynamies is necessary. Here is an example to find out the cause of the misengagement of flexible rapiers, by means of kineto-elastodynamic analysis, so as to meet the requirements of flexible rapier loom′s design, with beat-up and weft insertion mechanisms operating at high speed.
文摘In this paper, a review of the shuttleless looms’ development shows that three types of shuttleless looms: rapier, Jet and gripper projectile, are now equally matchable with each other. A prospect of the shuttleless loom’s development is also dealt with. It can be predicted that both rapier and Jet looms will be developed further and the future development of a new type of modern weaving looms will be prosperous in the coming 21st century.
文摘On the base of the study on dynamics of water jet in water jet looms, the parameters of water jet mechanism which affect the speed of water jet are analyzed and optimized. So the stability of the water jet can be improved to raise the speed of water jet as well as weft insertion rate and to enlarge the width of woven fabrics a lot. At the same time it also points out that to increase water jet speed and to prolong its affective jet time depend mainly on the accretion of spring rate (constant)of stiffness and the diminution of plunger's cross sectional area respectively.
基金Science and Technology Plan of Shanghai,China(No.12111101802)
文摘The motion laws for rapier weft insertion mechanism are analyzed. According to the special requirements on rapier loom's weft-insertion system for weaving three-dimensional( 3-D) fabric,a new rapier electronic weft-insertion system is presented. The design principle for 3-D loom's weft insertion system is introduced,including the design of the motion law of electronic weft-insertion system,the driving system's hardware configure,and its software's controlling principle. The weft insertion system is computer-controlled and servocylinder driven so as to control the rapier's movement to insert the weft into the multi-shed while 3-D weaving. This method greatly simplifies the weft-insertion system,achieves weft-insertion with variable travel,and improves the flexibility and reliability. The weft insertion system has been applied in a 3-D loom successfully.
文摘The figure of shuttle distribution one side of the loom has been used to show the convel-sion of shuttle in picking process.The characteristics of the figure have been analysed andused to introduce a simple method for shuttle starting distribution.
文摘Massive job losses are in the offing in the textile sector, says the theApparel Export Promotion Council (AEPC).The high prices of cotton have pushed up the cost of the fabric andthe end product. We are now in a situation where we are forced to rejectrepeat orders as we can’t justify the high prices to our foreign buyers.
文摘For Toyoda looms with air-jet weft insertion,the beat-ing-up mechanisms together with those of Tsudakomawater-jet looms are analyzed.Then by changing thecrank length of the four-bar-linkage for the air-jetlooms to get four specifications of reed travel correspond-ing to the series of Tsudakoma water-jet looms,it canbe proved by comparisons of displacements,velocities,accelerations and transmission pressure angles that thosetwo series of mechanisms have very similar kinematicproperties.So the possibility of developing a series of wa-ter-jet looms modified from Toyoda air-jet looms isproved.It is beneficial to save the machine cost andbroaden the machine types.
文摘The airflow in the reed groove of the air jet loom for the weft insertion includes the jet stream from the relay nozzle, the back leak stream from the reed, and the diffusion stream from the open side. The air velocity in the reed groove can be measured to analyze the influence of process parameters during the weft insertion. The relation between the air velocity and the relay nozzle distance, the jet angle or the supply pressure of the relay nozzle can be studied. In this paper, the pitot tube is applied to measure the air velocity in reed groove by the instrument designed. And the results indicate that the air velocity fluctuation in the reed groove is strong, and can drop from 150 m·s-1 to 80 m·s-1 drastically.
文摘Periodic variations of warp tension during a weaving cycle result in corresponding change of back rest position, and the oscillation of back rest affects the fluctuation of warp yarn in return. A mechanical model of back rest system of looms is presented on basis of auto control theory, and the factors affecting the dynamic performance of the back rest are analyzed. In the model, warp yarn is regarded as a viscoelastic medium, and the adjustable parameters and the adjusting range of the back rest system are increased, so the ioom's applicability for the fabric's variety is enlanced.Finally, the methods of designing and adjusting the back rest are discussed, and a trend of back rest system development is given.
文摘The water jet impulse is brought forward to study the traction force of the water jet to the flying weft in water-jet looms. The distribution of the water jet impulse in the shed is tested by a sensor, and the influence of water jet parameters on the water jet impulse is analyzed.
文摘A kind of gold in-woven fabric of Korean Goryeo Dynasty was successfully replicated on a Chinese draw loom with a major pattern sheet in The Yunjin Research Institute, Nanjing city.
文摘In the water jet looms, the distribution of the speed of water jet at the axis of the shed and its regularity are obtained by the Laser Doppler Tester. Based on the above, the water jet system is analyzed and the main effective approaches to increase the filling insertion rate and to widen the reed space of the loom are pointed out.
文摘In order to study the propulsive force on the water-jet to the flying weft in water-jet looms, a dynamic model has been established. Based on the analysis and example testing, an experiential formula of the propulsive force of the water-jet to the flying weft is obtained for the first time. The formula will profit the further research of the water-jet weft insertion and the production of textile.
