CN102242457B - Method and device for selecting magnetic levitation driven needle - Google Patents

Abstract

The present invention proposes a magnetic levitation driven knitting needle selection method and device, which integrates jacquard sheets, needle jacks, knitting needles and cams in the traditional knitting structure, and the knitting needles are not separated from the needle shell base during the action process. With the existence of impact friction and lateral force, it can realize the "three-station" movement of knitting needles with high speed and suspension control, and has the characteristics of simple structure, low cost and long service life.

Description

Method and device for selecting needles driven by magnetic levitation

technical field

The invention relates to a magnetic levitation driven knitting needle selection method and device, in particular to a knitting needle selection method and device for a computerized jacquard circular weft machine, belonging to the technical field of textile machinery products.

Background technique

In textile machinery, jacquard circular knitting machine is used to carry out jacquard on the fabric to weave various patterns and patterns. It is mainly composed of yarn feeding mechanism, loop forming mechanism, pulling and curling mechanism, transmission mechanism and auxiliary mechanism. The needle selection method and structure design of knitting needles is the direction of modern new loom technology improvement. The electronic needle selection devices of the known computerized jacquard circular weft machines are mainly electromagnetic and piezoelectric. Cams, jacquard pieces, needle jacks and other mechanical parts realize needle selection. Since the knitting needles realize the up and down knitting movement by contact with the triangular cams, the triangular cams in the knitting mechanism cause impact friction and lateral force on the knitting needles. With the continuous increase of the speed of the knitting machine (for example, the computerized jacquard circular machine is generally around 15-20rpm, and the frequency of the needle selection blade is within 100Hz), the performance requirements for the knitting needle and the triangular cam are higher. When the knitting needle and the triangular cam themselves When the strength, wear resistance, etc. reach the limit, the further increase of the speed is limited. According to data statistics, at present, domestic and foreign enterprises mainly focus on the wear resistance of knitting needle materials, heat treatment process and improvement design of knitting needle details, but have not made any changes to the driving principle and structure of knitting needles. The non-contact high-speed needle selection method and device using the principle of magnetic levitation to drive knitting needles have not been found in existing patents and related technical documents.

Contents of the invention

Aiming at the problems mentioned in the background technology, the present invention proposes a magnetic levitation driven knitting needle selection method and device, which integrates the jacquard sheets, needle jacks, knitting needles and cams in the traditional knitting structure, and the knitting needles in the action process Among them, there is no impact friction and lateral force with the base of the needle shell, and it can realize high-speed, levitation-controlled "three-position" movement of the knitting needle. It has the characteristics of simple structure, low cost, and long service life.

The technical solution of the present invention is: a magnetic levitation driven knitting needle selection device, including a knitting needle, a needle housing, a permanent magnet, a displacement sensor, an electromagnetic drive device and a control system, the knitting needle is installed in a cylindrical needle housing, and the knitting needle The bottom is a cylinder, and the head of the knitting needle is rectangular; it is characterized in that: there is an inwardly protruding radial support surface for the knitting needle inside the needle shell; the permanent magnet is disc-shaped, and the permanent magnet is installed on the knitting needle and coaxial with the bottom of the knitting needle; the displacement sensor is composed of a moving pole piece and a fixed pole piece, the moving pole piece is plated on the outer surface of the middle section of the knitting needle, and there are two embedded fixed pole pieces inside the middle of the needle shell The bottom of the needle housing is an electromagnetic driving device, and the control system installed on the loom has a wire connected to the electromagnetic driving device and the fixed pole piece on the needle housing; a rubber sheet is pasted on the upper surface of the electromagnetic driving device; The positional relationship between the pole piece and the fixed pole piece is: when the permanent magnet at the bottom of the knitting needle is in contact with the rubber sheet on the upper surface of the electromagnetic drive device, the first fixed pole piece is above the moving pole piece, and the second fixed pole piece The pole piece is located above the first fixed pole piece, and the knitting needle can slide up and down inside the needle housing. Its beneficial effect is: when the knitting needle is in the original state, it is set as the first station; The position when the movable pole piece is close to the second fixed pole piece in the needle shell is the third station. During the work, the magnetic levitation method is used to push the knitting needle from the first station to the second station or the third station. After hovering for a period of time, it returns to the first station and repeats itself to realize the high-speed, suspension-controlled "three-position" movement of the knitting needles, avoiding the impact, friction and friction caused by the needle selection device in the prior art. lateral force.

In the magnetic levitation driven knitting needle selection device described above, the displacement sensor is a differential capacitive displacement sensor, which is composed of a fixed pole piece and a moving pole piece. The fixed pole piece and the moving pole piece are cylindrical concentric structures. The pole piece is embedded inside the middle part of the needle shell; it is characterized in that: the fixed pole piece embedded in the inside of the needle shell is in the shape of a ring, and the inner surface of the ring is sequentially coated with a ring-shaped ceramic material base, a metal silver coating, Metal rhodium coating and polyethylene coating, along the axial direction, there are three equipotential ring coatings to separate the above-mentioned circular coatings; , followed by a ring-shaped metal rhodium coating, a metal silver coating and a ceramic material substrate. Its beneficial effects are: the metal rhodium coating helps to reduce the temperature coefficient of the pole piece, and improves the conductivity and relative sealing of the electrode; the polyethylene coating helps to improve the dielectric constant and increase the capacitance value; the equipotential ring helps to reduce the edge effect on capacitive devices.

The magnetic levitation driven knitting needle selection method is characterized in that it uses the magnetic levitation method to drive the electronic needle selection device of the knitting needle from the first station to the second station or the third station and then returns to the first station. ; The first station refers to the position when the permanent magnet at the bottom of the knitting needle is in contact with the rubber sheet on the electromagnetic drive device, and the second station refers to the moving pole piece on the knitting needle and the first pole piece in the needle housing. The position when the two fixed pole pieces approach, the second station is higher than the first station, and the third station refers to the position when the moving pole piece on the knitting needle is close to the second fixed pole piece in the needle housing , the third station is higher than the second station; during work, the control system of the loom loads the corresponding current to the electromagnetic drive device in the knitting needle device, and the magnetic field generated by the electromagnetic drive device after power-on and the permanent magnet magnetic field at the bottom of the knitting needle For the same polarity, repel the permanent magnet at the bottom of the knitting needle, push the knitting needle to rise along the axial direction of the needle shell, and at the same time, the displacement sensor detects the displacement signal of the knitting needle and sends it to the control system to control the knitting needle to reach the designated second station Or it is the third station, and after hovering at the second station or the third station for a period of time, the control system disconnects the power supply of the electromagnetic drive device, and the knitting needle is attracted by the permanent magnet at the bottom and the iron core of the electromagnetic drive device. Force and the gravity of the knitting needle itself, quickly fall to the first station, and repeat; adjust the driving current of the electromagnetic drive device, and the knitting needle can be controlled to hover at the second station or the third station. The beneficial effect is that the invention breaks through the mechanism and principle constraints of the traditional knitting machine when improving the performance of the knitting mechanism, and has the characteristics of high speed, high efficiency and low cost. the

Description of drawings

Accompanying drawing 1 is the appearance diagram of the knitting needle of the embodiment of the present invention;

Accompanying drawing 2 is the left view of Fig. 1;

Accompanying drawing 3 is a side cross-sectional view of Fig. 1;

Accompanying drawing 4 is the internal diagram of displacement sensor.

Detailed ways

Markings in the attached drawings:

Accompanying drawing 1, in accompanying drawing 2, 1—knitting needle, 3—needle shell.

In attached drawing 3, 2—fixed pole piece, 2'—fixed pole piece, 3—needle shell, 4—electromagnetic drive device, 5—permanent magnet, 6—moving pole piece, 7—radial support surface, 8—rubber piece.

In accompanying drawing 4, 2—fixed pole piece A, 9—equal potential ring, 10—ceramic material base, 11—silver coating, 12—rhodium coating, 13—polyethylene coating, 14—ceramic material base, 15—silver coating , 16-rhodium plating.

Embodiments of the present invention are further described below in conjunction with the accompanying drawings:

As shown in Figures 1 and 2, it is the middle knitting needle of the computerized jacquard circular weft machine, and the rest are outer knitting needles and inner knitting needles. The inner and outer knitting needles only have a right-angled bending shape at the head of the knitting needle, and their bottoms are It is a cylindrical cross-section, and the cross-section of the head of the knitting needle is rectangular. The present invention only takes the middle knitting needle as an example to illustrate the embodiment. the

Magnetic levitation driven knitting needle selection device is composed of knitting needle 1, needle housing 3, permanent magnet 5, displacement sensor, electromagnetic drive device 4 and control system. Knitting needle 1 is installed in cylindrical needle housing 3, knitting needle 1 The bottom of the knitting needle 1 is a cylindrical section, and the head of the knitting needle 1 is a rectangular section. Inside the needle housing 3 there is an inwardly protruding knitting needle radial support surface 7; the permanent magnet 5 is disc-shaped, and the permanent magnet 5 is installed on the bottom of the knitting needle 1 and is coaxial with the bottom of the knitting needle 1; the displacement sensor is driven by a dynamic pole piece 6 and fixed pole pieces 2 and 2', the moving pole piece 6 is plated on the outer surface of the middle section of the knitting needle, and there are two embedded fixed pole pieces 2 and 2' inside the middle of the needle shell 3; the bottom of the needle shell 3 It is an electromagnetic driving device 4, and the control system installed on the loom has wires connected with the fixed pole pieces 2 and 2' on the electromagnetic driving device 4 and the needle housing 3; the upper surface of the electromagnetic driving device 4 is pasted with a rubber sheet 8. The positional relationship between the moving pole piece 6 and the fixed pole piece is: when the permanent magnet 5 at the bottom of the knitting needle is in contact with the rubber sheet 8 on the upper surface of the electromagnetic drive device 4, the first fixed pole piece 2' is located on the moving pole piece 6, the second fixed pole piece 2 is located above the first fixed pole piece 2'.

See attached drawing 4, the displacement sensor is a differential capacitive displacement sensor, which is composed of fixed pole pieces 2, 2' and moving pole pieces (only fixed pole piece 2 is drawn in the figure, 2' is the same as 2), and fixed pole piece 2 The moving pole piece is a cylindrical concentric structure, the fixed pole piece 2 is embedded in the middle of the needle shell 3, the fixed pole piece 2 is in the shape of a ring, and the inner surface of the ring is coated with ring-shaped ceramics in turn from the outside to the radial direction of the center of the circle. Material substrate 10, metal silver coating 11, metal rhodium coating 12 and polyethylene coating 13, along the axial direction, there are three equipotential ring coatings 9 to isolate and separate the above-mentioned circular coatings; coated on the outer surface of the middle section of knitting needle 1 The moving pole piece, from the outer cylinder to the radial direction of the center of the circle, is followed by a ring-shaped metal rhodium coating 16, a metal silver coating 15 and a ceramic material base 14.

The magnetic levitation driven knitting needle selection method of the present invention, the action process is as follows: in the original state, the knitting needle 1 is vertically located in the needle housing 3, and its radial direction is supported by the radial support surface 7 in the needle housing 3, and the lower end of the knitting needle 1 The permanent magnet 5 is in contact with the rubber sheet 8 pasted on the electromagnetic drive device 4, which is the first station of the knitting needle 1; when the loom control system loads a corresponding current to the electromagnetic drive device 4 in the knitting needle 1, The electromagnetic drive device 4 is energized to generate a magnetic field with the same polarity as the permanent magnet 5 at the bottom of the knitting needle 1. The magnetic field repels the permanent magnet 5 and drives the knitting needle 1 to rise along the axial direction of the needle shell 3. When the moving pole piece on the knitting needle 1 6 When approaching the first fixed pole piece 2' in the needle housing 3 (the second station), the control system detects that the displacement signal of the knitting needle 1 is in the second station, and the knitting needle 1 hovers at the second station. station, the hovering time is the set value, when the process requires that the knitting needle 1 continues to rise, the control system will increase the driving current, and the knitting needle 1 will rise upwards. Similarly, when the moving pole piece 6 on the knitting needle 1 and the needle shell When the second fixed pole piece 2 on 3 approaches (the third station), the control system detects that the displacement signal of the knitting needle 1 is in the third station, at this time the knitting needle 1 hovers at the third station, and presses The process requires hovering at the third station for a certain period of time. After the knitting needle 1 hovers at the second station or the third station for a certain period of time and completes the work, the control system disconnects the power supply of the electromagnetic drive device 4, and the knitting needle 1 is due to the gap between the bottom permanent magnet 5 and the iron core of the electromagnetic drive device 4. The superimposed effect of the attraction force between the knitting needle and the gravity of the knitting needle itself makes the knitting needle 1 quickly fall to the initial position (the first station), and repeats itself. Adjusting the driving current of the electromagnetic drive device can control the hovering position of the knitting needle. The invention breaks through the mechanism and principle constraints of the traditional knitting machine when improving the performance of the knitting mechanism, and has the characteristics of high speed, high efficiency and low cost.

In the embodiment of the present invention, the hovering time of the knitting needle 1 at each station is ~4ms, its positioning accuracy is 0.2mm, the working frequency of the knitting needle (frequency of reciprocating up and down) is not less than 100Hz, and the reciprocating working stroke is about 10mm. the

The following is the efficiency comparison between the embodiment of the present invention and the traditional computerized jacquard machine (using eight-stage needle selection device):

Assuming that there are 2256 knitting needles in the traditional jacquard machine, each group of 8 knitting needles has 72 yarns, that is, there are 72 sets of needle selectors and triangle (cam) and other needle selection mechanisms. The jacquard machine uses an eight-stage piezoelectric ceramic needle selector, and its maximum operating frequency is 100HZ, which is also the operating frequency of the needle selection knife. Assume that the needle cylinder speed is 15r/min, that is, 1/4 revolution per second. After calculation, the circular knitting machine using the needle selection knife, the highest frequency of the needle selector converted to the action frequency of knitting needles is 24Hz. If the suspended knitting needle of the present invention is adopted, since there is no intermediate transmission mechanism, the movement of the knitting needle is directly controlled by electromagnetic force. According to the knitting process, the shortest time for the knitting needle to complete a knitting action is 6ms, that is, the knitting The needle action frequency is 167Hz. Compared with the two, the efficiency of the knitting needle of the present invention is increased by more than 6 times. According to the theory and application of the magnetic levitation technology, this efficiency is theoretically feasible.

On the other hand, since the magnetic levitation needle does not have rigid impact and impact friction, under the same material, the life of the needle must be many times longer than that of the traditional one.

Claims (3)

1. Magnetic levitation driven knitting needle selection device, including knitting needles, needle housings, permanent magnets, displacement sensors, electromagnetic drive devices and control systems. The knitting needles are installed in cylindrical needle housings, and the bottom of the knitting needles is a cylinder. The head of the knitting needle is rectangular; it is characterized in that: there is an inwardly protruding radial support surface for the knitting needle inside the needle shell; the permanent magnet is disc-shaped, and the permanent magnet is installed at the bottom of the knitting needle and The bottom of the knitting needle is coaxial; the displacement sensor is composed of a moving pole piece and a fixed pole piece. The bottom of the loom is an electromagnetic driving device, and the control system installed on the loom has wires connected with the electromagnetic driving device and the fixed pole piece on the needle shell; the upper surface of the electromagnetic driving device is pasted with a rubber sheet; the moving pole piece and the fixed pole piece The positional relationship between the pieces is: when the permanent magnet at the bottom of the knitting needle is in contact with the rubber sheet on the upper surface of the electromagnetic drive device, the first fixed pole piece is located above the moving pole piece, and the second fixed pole piece is located above the first one. Above the fixed pole piece, the knitting needle can slide up and down inside the needle housing. 2. The magnetic levitation driven knitting needle selection device according to claim 1, wherein the displacement sensor is a differential capacitive displacement sensor, which is composed of a fixed pole piece and a moving pole piece, and the fixed pole piece and the moving pole piece are cylinders Shaped concentric structure, the fixed pole piece is embedded in the middle of the needle shell; it is characterized in that: the fixed pole piece embedded in the inside of the needle shell is in the shape of a ring, and the inner surface of the ring is sequentially coated with a ring-shaped ceramic material base from the outside to the radial direction of the center of the circle. , metal silver coating, metal rhodium coating and polyethylene coating, along the axial direction, there are three equipotential ring coatings to separate the above-mentioned circular coatings; Facing the radial direction of the center of the circle, there are ring-shaped metal rhodium coating, metal silver coating and ceramic material base in sequence. 3. The magnetic levitation driven knitting needle selection method is characterized in that: the magnetic levitation method is used to drive the electronic needle selection device of the knitting needle to rise from the first station to the second station or the third station and then return to the first station method; the first station refers to the position where the permanent magnet at the bottom of the knitting needle is in contact with the rubber sheet on the upper surface of the electromagnetic drive device, and the second station refers to the moving pole piece on the knitting needle and the The position when the first fixed pole piece approaches, the second station is higher than the first station, and the third station refers to when the moving pole piece on the knitting needle is close to the second fixed pole piece in the needle housing position, the third station is higher than the second station; during work, the control system of the loom loads the corresponding current to the electromagnetic drive device in the knitting needle device, and the magnetic field generated after the electromagnetic drive device is energized and the permanent magnet at the bottom of the knitting needle The magnetic field of the magnet is the same polarity, repels the permanent magnet at the bottom of the needle, and pushes the needle up along the axial direction of the needle shell. At the same time, the displacement sensor detects the displacement signal of the needle and sends it to the control system to control the needle to reach the specified second station or the third station, and after hovering at the second station or the third station for a period of time, the control system cuts off the power supply of the electromagnetic drive device, and the knitting needle is The attraction force between the knitting needles and the gravity of the knitting needles will quickly fall to the first station, and the cycle will start again and again; the driving current of the electromagnetic drive device can be adjusted to control the knitting needles to hover at the second station or the third station.

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