Yarn processing machine

Abstract

To enable cost to be reduced and maintain high temperature of a heating member relating to a yarn traveling direction.SOLUTION: A first heating device 13 has a heat source 51, a heated part 52 heated by the heat source 51, and a control device 100 to control temperature of the heat source 51. The heated part 52 has a yarn contact part 54 provided with a yarn contact surface 56 that extends at least in a prescribed extension direction and makes contact with the traveling yarn, and a heating member 53 to receive the heat generated by the heat source 51 and heat the yarn contact part 54. The heating member 53 is formed of metal containing aluminum. The control device 100 controls the temperature of the heat source 51 so that the temperature of the heating member 53 is restricted to 320°C or lower.SELECTED DRAWING: Figure 5

Description

[Technical Field]

[0001] The present invention relates to a yarn processing machine equipped with a heating device for heating yarn. [Background technology]

[0002] Heating devices for heating yarns in yarn processing machines that perform various processes, such as doubling and false twisting, on synthetic fiber yarns have been known for some time. For example, Patent Document 1 discloses a heating device equipped with a heater block (heating element) that is heated by a heat source (heat source) such as a sheathed heater. In such a heating device, the yarn travels through a yarn traveling space that is heated by the heating element. As a result, the yarn is heated to a predetermined processing temperature by the gas in the traveling space. In other words, this heating device is a non-contact heating device. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2002-220755 Summary of the Invention [Problem to be solved by the invention]

[0004] Generally, in the heating device described above, brass, which has a relatively high heat resistance, is used as the material for the heating element. Here, it is preferable that the heating element has a relatively large heat capacity in order to reduce temperature fluctuations of the heating element due to external disturbances. However, because brass has a relatively low specific heat, ensuring a certain level of heat capacity for the brass heating element increases the mass of the heating element and increases costs.

[0005] In the heating device described above, the temperature of a predetermined position (control point) in the yarn traveling direction on the heating element is controlled to a predetermined temperature. However, because brass has a relatively low thermal conductivity, the temperature of a brass heating element decreases significantly at a portion farther from the control point in the yarn traveling direction.

[0006] An object of the present invention is to provide a yarn processing machine which can reduce costs and can maintain a high temperature of the heating element in the yarn running direction. [Means for solving the problem]

[0007] A yarn processing machine according to a first aspect of the present invention has a heating device that heats a running synthetic yarn, the heating device including a heat source, a heating section heated by the heat source, and a control unit that controls the temperature of the heat source. The heating section includes a yarn contact section having a yarn contact surface for contacting the running yarn, and a heating element that receives heat generated by the heat source and heats the yarn contact section, the heating element being made of a metal containing aluminum. The control unit controls the temperature of the heat source so that the temperature of the heating element is limited to 320°C or less.

[0008] The present invention uses a contact method in which the yarn is heated by contacting the yarn contact surface, so the set temperature of the heat source can be lower than in the case of a non-contact method. That is, the yarn can be properly heated even when the temperature of the heating element is 320°C or lower. Therefore, aluminum, which has a relatively low melting point, can be used as the material for the heating element. Aluminum has a relatively high specific heat and a relatively low specific gravity, so a certain degree of heat capacity can be ensured with a smaller mass than brass. This allows for cost reduction. Furthermore, aluminum has a higher thermal conductivity than brass, so the temperature of the heating element in the yarn running direction can be maintained high.

[0009] The heat source is a resistance heating type heat source that generates heat by passing an electric current through a heating wire such as a nichrome wire, etc. An example of a resistance heating type heat source is a sheath heater.

[0010] In the yarn processing machine of the second invention, the yarn contact portion extends in an extension direction that intersects at least with the vertical direction, and the heating device is installed so that the yarn contact surface faces at least downward and so that the inclination angle of the yarn contact surface with respect to the horizontal direction is between -60° and +60° in a cross section parallel to both the vertical direction and the extension direction.

[0011] In the present invention, when a yarn breakage occurs, the yarn can be quickly separated from the yarn contact surface by its own weight, thereby preventing the yarn from melting in the heating device and adhering to the heating device.

[0012] In the yarn processing machine of the third invention, the heat source generates heat when an electric current is supplied thereto, and further includes a sensor that detects the temperature of the heating element, and a current supply circuit that can supply electric current to the heat source, and the control unit controls the current supply circuit based on the detection value of the sensor, and switches between a state in which electric current is supplied to the heat source and a state in which electric current is not supplied.

[0013] In the present invention, control can be simplified and costs can be reduced compared to when the magnitude of the current or voltage supplied to the heat source is controlled.

[0014] The yarn processing machine according to a fourth aspect of the present invention further comprises a circuit breaker that cuts off the current supplied to the heat source when the temperature of the heating element reaches a predetermined temperature of 400°C or higher and 450°C or lower.

[0015] In the present invention, even if the control unit is unable to control the temperature of the heating element due to a sensor failure or the like, the circuit breaker can cut off the current supplied to the heat source when the temperature of the heating element reaches a predetermined temperature of 400° C. or higher and 450° C. or lower. Therefore, it is possible to suppress an increase in the temperature of the heating element and avoid a decrease in the strength of the heating element. [Brief explanation of the drawings]

[0016] [Figure 1] 1 is a side view of a false twisting machine according to an embodiment of the present invention. [Figure 2] FIG. 1 is a schematic diagram showing a false twisting machine laid out along the yarn path. [Figure 3] FIG. 2 is a diagram showing a first heating device. [Figure 4] FIG. 4 is a cross-sectional view taken along line IV-IV in FIG. [Figure 5] FIG. 5 is a cross-sectional view taken along line VV in FIG. [Figure 6] FIG. 6 is a cross-sectional view taken along line VI-VI in FIG. [Figure 7] FIG. 10 is an explanatory diagram illustrating the definition of the inclination angle of the yarn contact surface with respect to the horizontal direction. [Figure 8] 10(a) and 10(b) are explanatory diagrams showing the limit of the inclination angle of the yarn contact surface relative to the horizontal direction. [Figure 9] 10 is a graph showing the temperature distribution on the yarn contact surface when using each heating member according to the example and the comparative example. [Figure 10] 10 is a graph showing power consumption when using each heating element according to an example and a comparative example. [Figure 11] 1 is a table showing the physical properties of aluminum and brass. DETAILED DESCRIPTION OF THE INVENTION

[0017] A false twisting machine 1 according to a preferred embodiment of the present invention will be described with reference to Fig. 1. The direction perpendicular to the plane of the paper in Fig. 1 is the machine base longitudinal direction, and the left-right direction of the paper is the machine base width direction. The direction perpendicular to both the machine base longitudinal direction and the machine base width direction is the up-down direction (vertical direction) in which gravity acts. The machine base longitudinal direction and the machine base width direction are directions approximately parallel to the horizontal direction.

[0018] (Overall configuration of false twisting machine) The false twisting machine 1 is configured to be able to false twist a yarn Y made of a synthetic fiber such as nylon (a polyamide fiber) or polyester. The false twisting machine 1 includes a yarn supplying section 2 for supplying the yarn Y, a processing section 3 for false twisting the yarn Y supplied from the yarn supplying section 2, and a winding section 4 for winding the yarn Y processed by the processing section 3 onto a winding bobbin Bw. A plurality of components of the yarn supplying section 2, the processing section 3, and the winding section 4 are arranged in the longitudinal direction of the machine base (see FIG. 2). The longitudinal direction of the machine base is a direction perpendicular to the running plane of the yarn Y (the plane of the paper in FIG. 1) formed by the yarn path from the yarn supplying section 2 through the processing section 3 to the winding section 4.

[0019] The yarn supplying section 2 has a creel stand 5 that holds multiple yarn supply packages Ps. The yarn supplying section 2 supplies multiple yarns Y to the processing section 3. The processing section 3 false-twists the yarns Y supplied from the yarn supply packages Ps. The processing section 3 is configured to include, in order from upstream in the yarn running direction, a first feed roller 11, a twist stop guide 12, a first heating device 13 (corresponding to the "heating device" of the present invention), a cooling device 14, a false-twisting device 15, a second feed roller 16, an intertwining device 17, a third feed roller 18, a second heating device 19, and a fourth feed roller 20. The winding section 4 has multiple winding devices 21. Each winding device 21 winds the yarn Y false-twisted in the processing section 3 onto a winding bobbin Bw to form a winding package Pw.

[0020] The false twisting machine 1 has a main machine base 8 and a winding table 9 arranged at a distance in the width direction of the machine base. The main machine base 8 and the winding table 9 extend over approximately the same length in the longitudinal direction of the machine base. The main machine base 8 and the winding table 9 are arranged to face each other in the width direction of the machine base. The upper part of the main machine base 8 and the upper part of the winding table 9 are connected by a support frame 10. The devices that make up the processing unit 3 are mainly attached to the main machine base 8 and the support frame 10. The devices that make up the winding unit 4 are attached to the winding table 9. The main machine base 8, the winding table 9, and the support frame 10 form a work space A where an operator can perform tasks such as threading on each device. The yarn path is formed so that the yarn Y mainly runs around the work space A.

[0021] The false twisting machine 1 has a unit called a span, which includes a pair of a main machine base 8 and a winding table 9 arranged opposite each other. In one span, a plurality of processing units (also called spindles) are arranged in a row in the longitudinal direction of the machine base, with yarn paths formed so that they pass through the devices that make up the processing section 3. This allows one span to simultaneously false twist a plurality of yarns Y that run in a row in the longitudinal direction of the machine base. In the false twisting machine 1, the spans are arranged symmetrically on the left and right sides of the page, with the center line C of the main machine base 8 in the width direction of the machine base as the axis of symmetry. The main machine base 8 is common to the left and right spans.

[0022] (Configuration of processing part) The configuration of the processing unit 3 will be described with reference to Figures 1 and 2. The first feed roller 11 is configured to unwind the yarn Y from the yarn supply package Ps attached to the yarn supplying unit 2 and feed it to the first heating device 13. For example, as shown in Figure 2, the first feed roller 11 is configured to feed one yarn Y to the first heating device 13. Alternatively, the first feed roller 11 may be configured to feed each of adjacent yarns Y downstream in the yarn traveling direction. The twist stop guide 12 is configured to prevent the twist imparted to the yarn Y by the false twist device 15 from propagating upstream of the twist stop guide 12 in the yarn traveling direction.

[0023] The first heating device 13 is a device for heating the yarn Y fed from the first feed roller 11 to a predetermined processing temperature. The first heating device 13 is configured to be able to heat two yarns Y, for example, as shown in Fig. 2. The first heating device 13 will be described in more detail below.

[0024] The cooling device 14 is configured to cool the yarn Y heated by the first heating device 13. For example, as shown in FIG. 2, the cooling device 14 is configured to cool one yarn Y. Alternatively, the cooling device 14 may be configured to simultaneously cool multiple yarns Y. The false twisting device 15 is disposed downstream of the cooling device 14 in the yarn running direction and is configured to impart a twist to the yarn Y. The false twisting device 15 is, for example, a so-called disk friction type false twisting device, but is not limited to this. The second feed roller 16 is configured to feed the yarn Y processed by the false twisting device 15 to the entangling device 17. The conveying speed of the yarn Y by the second feed roller 16 is faster than the conveying speed of the yarn Y by the first feed roller 11. As a result, the yarn Y is stretch-false-twisted between the first feed roller 11 and the second feed roller 16.

[0025] The interlacing device 17 is configured to interlace the yarn Y. The interlacing device 17 has, for example, a known interlace nozzle that interlaces the yarn Y by airflow.

[0026] The third feed roller 18 is configured to feed the yarn Y traveling downstream of the intertwining device 17 in the yarn traveling direction to the second heating device 19. For example, as shown in FIG. 2 , the third feed roller 18 is configured to feed one yarn Y to the second heating device 19. Alternatively, the third feed roller 18 may be configured to feed each of multiple adjacent yarns Y downstream in the yarn traveling direction. The conveyance speed of the yarn Y by the third feed roller 18 is slower than the conveyance speed of the yarn Y by the second feed roller 16. Therefore, the yarn Y is relaxed between the second feed roller 16 and the third feed roller 18.

[0027] The second heating device 19 is configured to heat the yarn Y fed from the third feed roller 18. The second heating device 19 extends vertically, with one second heating device 19 provided per span. The fourth feed roller 20 is configured to feed the yarn Y heated by the second heating device 19 to the winding device 21. For example, as shown in FIG. 2 , the fourth feed roller 20 is configured to be capable of feeding a single yarn Y to the winding device 21. Alternatively, the fourth feed roller 20 may be configured to be capable of feeding each of multiple adjacent yarns Y downstream in the yarn traveling direction. The conveyance speed of the yarn Y by the fourth feed roller 20 is slower than the conveyance speed of the yarn Y by the third feed roller 18. Therefore, the yarn Y is relaxed between the third feed roller 18 and the fourth feed roller 20.

[0028] In the processing unit 3 configured as described above, the yarn Y drawn between the first feed roller 11 and the second feed roller 16 is twisted by the false twist device 15. The twist formed by the false twist device 15 propagates up to the twist stop guide 12, but does not propagate upstream of the twist stop guide 12 in the yarn traveling direction. The yarn Y, to which twist has been imparted while being drawn, is heated and heat-set by the first heating device 13, and then cooled by the cooling device 14. The yarn Y is untwisted downstream of the false twist device 15 in the yarn traveling direction, but the wavy false-twisted state of the yarn Y is maintained by the heat-setting (i.e., the crimp of the yarn Y is maintained).

[0029] The false-twisted yarn Y is entangled by an entangling device 17 while being relaxed between the second feed roller 16 and the third feed roller 18, and then guided downstream in the yarn running direction. The yarn Y is then heat-treated by a second heating device 19 while being relaxed between the third feed roller 18 and the fourth feed roller 20. Finally, the yarn Y sent from the fourth feed roller 20 is wound by a winding device 21.

[0030] (Configuration of winding section) The configuration of the winding unit 4 will be described with reference to FIG. 2. The winding unit 4 has a plurality of winding devices 21. Each winding device 21 is configured to be able to wind the yarn Y onto one winding bobbin Bw. The winding device 21 has a fulcrum guide 41, a traverse device 42, and a cradle 43. The fulcrum guide 41 is a guide that serves as a fulcrum when the yarn Y is traversed. The traverse device 42 is configured to be able to traverse the yarn Y using the traverse guide 45. The cradle 43 is configured to rotatably support the winding bobbin Bw. A contact roller 46 is disposed near the cradle 43. The contact roller 46 comes into contact with the surface of the winding package Pw and applies contact pressure. In the winding unit 4 configured as described above, the yarn Y fed from the fourth feed roller 20 is wound onto the winding bobbin Bw by each winding device 21 to form the winding package Pw.

[0031] (Configuration of the first heating device) Next, a more specific configuration of the first heating device 13 will be described with further reference to Figs. 3 to 6. As shown in Fig. 3, the first heating device 13 extends in a predetermined extension direction perpendicular to the longitudinal direction of the machine base. The extension direction is a direction intersecting with the up-down direction (vertical direction). In the following description, the direction perpendicular to both the longitudinal direction of the machine base and the extension direction is referred to as the height direction.

[0032] The first heating device 13 is configured to heat the traveling yarn Y. In this embodiment, the first heating device 13 is configured to be able to heat, for example, two yarns Y (yarns Ya and Yb: see FIG. 4).

[0033] 4 and 5, the first heating device 13 mainly includes a heat source 51, a heating section 52, a sensor 57 for detecting the temperature of the heating section 52, a current application circuit 58, a thermostat 70, a heat insulator 59, a box 60, and a control device 100. The first heating device 13 heats the running yarns Ya and Yb simultaneously by bringing the yarns Ya and Yb into contact with the heating section 52 heated by the heat source 51.

[0034] The heat source 51 is a resistance heating type heat source that generates heat by passing an electric current through a heating wire such as a nichrome wire. An example of a resistance heating type heat source is a sheathed heater that has a heating wire (e.g., a coil) and a pipe surrounding the heating wire. The heat source 51 extends along the extension direction. The heating length (length along the extension direction) of the heat source 51 is, for example, 1.0 m. The heat source 51 is connected to a current supplying circuit 58. The current supplying circuit 58 is a circuit for passing an electric current through the heating wire of the heat source 51. The heat source 51 generates Joule heat when the current supplying circuit 58 supplies an electric current to the heating wire.

[0035] The current application circuit 58 is electrically connected to the control device 100. The control device 100 may be electrically connected to devices constituting the false twisting machine 1 in addition to the current application circuit 58 of the first heating device 13. The control device 100 controls the ON / OFF of the current application circuit 58 (PWM control) based on the output signal of the sensor 57, switching between a state in which current is supplied to the heating wire of the heat source 51 and a state in which current is not supplied. As a specific example, when the detection value of the sensor 57 is sufficiently lower than the target temperature, the control device 100 maintains a state in which current is supplied to the heating wire. Then, when the detection value of the sensor 57 approaches the target temperature, the control device 100 adjusts the time period in which current is supplied to the heating wire and the time period in which current is not supplied to the heating wire so as not to exceed the target temperature. On the other hand, when the detection value of the sensor 57 is sufficiently higher than the target temperature, the control device 100 maintains a state in which current is not supplied to the heating wire. When the detection value of sensor 57 approaches the target temperature, the time when no current is supplied to the heating wire and the time when current is supplied to the heating wire are adjusted to control the temperature so that it does not fall below the target temperature. Note that the target temperature is set appropriately depending on operating conditions such as the type of yarn Y, the brand (thickness) of yarn Y, and the running speed of yarn Y.

[0036] As described above, the control device 100 can control the temperature of the heat source 51 (the heating temperature of the first heating device 13). The control point of the temperature control by the control device 100 is the portion of the heating unit 52 where the sensor 57 is provided (the central portion in the extension direction).

[0037] The control device 100 also manages the upper limit of the heating temperature of the first heating device 13. That is, the control device 100 controls the value detected by the sensor 57 so that it is limited to 320°C or less. As a specific example, when the value detected by the sensor 57 rises to a predetermined upper limit temperature of 320°C or less, the control device 100 stops supplying current to the heating wire and lowers the temperature of the heat source 51. Note that the above-mentioned upper limit temperature is a fixed value and is not changed depending on operating conditions such as the type of yarn Y, the brand (thickness) of the yarn Y, or the running speed of the yarn Y.

[0038] The thermostat 70 is disposed between the current applying circuit 58 and the heat source 51. When the temperature of the heating member 53 reaches a predetermined abnormal temperature of 400°C or higher and 450°C or lower, the thermostat 70 physically cuts off the circuit between the current applying circuit 58 and the heat source 51. This cuts off the current supplied to the heat source 51. In other words, the thermostat 70 corresponds to the "circuit breaker" of the present invention.

[0039] The heating unit 52 is configured to be heated by the heat generated by the heat source 51. As shown in FIG. 5, the heating unit 52 extends in the extension direction along the heat source 51. The heating unit 52 has, for example, two heating members 53 (heating members 53a and 53b) and two yarn contact members 54 (yarn contact members 54a and 54b). The heating member 53a and the yarn contact member 54a are members for heating the yarn Ya. The heating member 53b and the yarn contact member 54b are members for heating the yarn Yb. The member for heating the yarn Ya and the member for heating the yarn Yb are disposed, for example, on opposite sides of the heat source 51 in the machine longitudinal direction.

[0040] The member for heating the yarn Ya will be described. The heating member 53a is made of aluminum or an aluminum alloy. The heating member 53a extends in the extension direction along the heat source 51. The heating member 53a is arranged so as to be in contact with the heat source 51. The heating member 53a is arranged, for example, on one side of the heat source 51 in the machine frame longitudinal direction (the left side of the paper in FIG. 4). The heating member 53a has, for example, a slit 55 (slit 55a) extending in the extension direction. The slit 55a is an inverted U-shaped slit in a cross section perpendicular to the extension direction. The slit 55a is open on one side in the height direction (the upper side of the paper in FIG. 4) and the other side (the lower side of the paper in FIG. 4). The yarn contact portion 54 (yarn contact portion 54a) is housed within the slit 55a.

[0041] The yarn contact portion 54a is a member that forms a yarn path along which the yarn Ya travels. The yarn contact portion 54a is a long member made of, for example, SUS. The yarn contact portion 54a extends at least in the extension direction. The yarn contact portion 54a is fixed to the heating member 53a while in contact with the heating member 53a. The temperature of the yarn contact portion 54a is increased by heat transferred from the heat source 51 via the heating member 53a. The yarn contact portion 54a has a yarn contact surface 56 (yarn contact surface 56a) with which the yarn Y comes into contact. The yarn contact surface 56a faces at least the other side in the height direction. As shown in FIG. 6, the yarn contact surface 56a is curved in a substantially U-shape that bulges convexly toward the other side in the height direction in a cross section perpendicular to the longitudinal direction of the machine. As shown in FIG. 4, when viewed from the extension direction, the yarn contact surface 56a is curved in a substantially inverted U-shape that bulges convexly toward one side in the height direction.

[0042] Next, a member for heating the yarn Yb will be described. Heating member 53b is disposed, for example, on the other side of heat source 51 in the machine longitudinal direction (the right side of the paper in FIG. 4). Heating member 53b is in contact with heat source 51. Heating member 53b has slit 55b with a shape similar to slit 55a. Yarn contact portion 54b with a structure similar to yarn contact portion 54a is housed within slit 55b. Yarn contact portion 54b has yarn contact surface 56b with a shape similar to yarn contact surface 56a. Further details will be omitted.

[0043] As shown in Figures 4 and 5, the sensor 57 is disposed at one end of the heating unit 52 in the height direction. More specifically, as shown in Figure 4, the sensor 57 is disposed in a recess 52a formed across the end faces of the heating members 53a, 53b on one side in the height direction. This allows the sensor 57 to detect the temperature of the heating member 53 in the heating unit 52. The sensor 57 is disposed on one side of the heat source 51 in the height direction. As shown in Figure 5, the sensor 57 is disposed in the central part of the heating unit 52 in the extension direction, at a position overlapping with the heat source 51 in the height direction.

[0044] The heating unit 52 is housed in a box 60. The box 60 is a hollow member having a rectangular parallelepiped shape with the extension direction as the longitudinal direction. An opening 61 is formed in the side wall on the other side in the height direction of the box 60. The opening 61 connects the spaces within the slits 55 formed in each of the two heating members 53 with the space outside the box 60. In addition, openings 62 and 63 are formed in the side walls on both ends in the extension direction of the box 60. The openings 62 and 63 connect the spaces within the slits 55 formed in each of the two heating members 53 with the space outside the box 60.

[0045] A plurality of insulating materials 59 are arranged to fill the gap between the box 60 and the heating unit 52 housed in the box 60. The wall surfaces on both sides of the heating unit 52 in the machine base longitudinal direction and in the height direction are covered with the plurality of insulating materials 59. The wall surfaces on both sides of the heating unit 52 in the extension direction are not covered with insulating materials 59 and are exposed to the outside air. Furthermore, no insulating material 59 is arranged on the other side of the slit 55 in the height direction.

[0046] 4 and 6, the space on the other side (more precisely, below) in the height direction of the yarn contact surface 56 of the yarn contact portion 54 housed in the slit 55 is open. "Open" means that in the first heating device 13, no component is arranged on an extension line to the lower side of the yarn contact surface 56, and a space is formed in which the yarn Y can fall off the first heating device 13 under its own weight in the event of yarn breakage.

[0047] Here, the positional relationship between the first heating device 13 and the twist stop guide 12 and the positional relationship between the first heating device 13 and the cooling device 14 are appropriately set so that the yarn Y reliably contacts the yarn contact surface 56 when the yarn Y is running normally. In other words, a force is applied to the yarn Y running along the yarn contact surface 56 toward the yarn contact surface 56 at least in the height direction. This prevents the yarn Y from separating from the yarn contact surface 56.

[0048] In the first heating device 13 having the above configuration, the yarn Y comes into contact with the yarn contact surface 56 while traveling, and receives heat from the heating unit 52 via the yarn contact surface 56 (contact method). This heats the yarn Y. By appropriately setting the type of yarn Y, the brand (thickness) of the yarn Y, the traveling speed of the yarn Y, and the heating temperature, the temperature of the yarn Y can be adjusted to an optimal processing temperature. In the first heating device 13, the heating temperature and the processing temperature do not necessarily coincide. The heating temperature is often set higher than the target processing temperature.

[0049] (Arrangement of first heating device) The arrangement of the first heating device 13 will be described in more detail with further reference to FIGS.

[0050] As described above, in a cross section perpendicular to the longitudinal direction of the machine (in other words, a cross section parallel to both the up-down direction and the extension direction), the yarn contact surface 56 is curved in a substantially U-shape. More specifically, the central portion of the yarn contact surface 56 in the extension direction (the portion near point P0 shown in FIG. 7) is substantially parallel to the extension direction. Both sides of the central portion of the yarn contact surface 56 in the extension direction are inclined with respect to the extension direction. The portions near one end (point P1 shown in FIG. 7) and the other end (point P2 shown in FIG. 7) in the extension direction of the yarn contact surface 56 are most inclined with respect to the extension direction. For example, as shown in FIG. 7, when the first heating device 13 is arranged so that the extension direction is substantially parallel to the horizontal direction, the portion near point P0 in the cross section perpendicular to the longitudinal direction of the machine is substantially parallel to the horizontal direction. Furthermore, the portions near points P1 and P2 are significantly inclined with respect to the horizontal direction.

[0051] As shown in Figure 7, in a cross section perpendicular to the machine base longitudinal direction, the angle of inclination of a portion near point P1 with respect to the horizontal direction is defined as angle θ1. Also, in the same cross section, the angle of inclination of a portion near point P2 with respect to the horizontal direction is defined as angle θ2. Detailed definitions of angles θ1 and θ2 are explained below.

[0052] In a cross section perpendicular to the longitudinal direction of the machine, the angle θ1 is the angle between one portion (tangent line T1) of the tangent line passing through point P1 of the tangent surface 56 in the extending direction and a substantially horizontal straight line L1 extending along the width direction of the machine. When the tangent line T1 is located above the straight line L1 (see Figures 7 and 8(a)), the angle θ1 is considered to have a positive value. When the tangent line T1 is located below the straight line L1 (see Figure 8(b)), the angle θ1 is considered to have a negative value.

[0053] In a cross section perpendicular to the longitudinal direction of the machine, angle θ2 is the angle between one portion (tangent T2) of the tangent passing through point P2 of the yarn contact surface 56 in the extending direction and a substantially horizontal straight line L2 extending along the width direction of the machine. When tangent T2 is located above straight line L2 (see FIG. 8(a)), angle θ2 is considered to have a positive value. When tangent T2 is located below straight line L2 (see FIGS. 7 and 8(b)), angle θ2 is considered to have a negative value. In a cross section perpendicular to the longitudinal direction of the machine, the inclination angle of the portion of yarn contact surface 56 between points P1 and P2 with respect to the horizontal direction is between angle θ1 and angle θ2.

[0054] In this embodiment, the inclination angle of the yarn contact surface 56 with respect to the horizontal direction is between -60° and +60°. More specifically, the inclination angle of the entire yarn contact surface 56 from point P1 to point P2 (i.e., the entire portion in the extending direction of the yarn contact surface 56) is between -60° and +60° with respect to the horizontal direction. In this embodiment, when both the angle θ1 and the angle θ2 are between -60° and +60°, the inclination angle of the entire yarn contact surface 56 with respect to the horizontal direction is between -60° and +60°.

[0055] As described above, the space below (directly below) the yarn contact surface 56 in the first heating device 13 is open, and the inclination angle of the yarn contact surface 56 relative to the horizontal direction in a cross section perpendicular to the longitudinal direction of the machine falls within a predetermined range. Therefore, when a yarn breakage occurs during operation of the false twisting machine 1, the yarn Y can be quickly separated from the yarn contact surface 56 by its own weight, and further, the yarn Y can be dropped from the first heating device 13. This makes it possible to prevent the yarn Y from fusing to the first heating device 13 when the yarn breakage occurs.

[0056] (Comparative test) The inventors of the present application conducted a comparative test between a case in which aluminum was used as the material for the heating element as in this embodiment (Example) and a case in which brass was used as the material for the heating element (Comparative Example). Fig. 9 is a graph showing the temperature distribution in the extending direction of the yarn contact surface when the heating elements according to the Example and Comparative Example were used and the set temperatures were 100°C, 200°C, and 300°C (when the temperature of the heating part (temperature at the control point) detected by the sensor was controlled to 100°C, 200°C, and 300°C). In both the Example and Comparative Example, the heat capacity of the heating element was 2904 J / K.

[0057] 9, in the test at any set temperature, when aluminum was used as the heating element material (Example), the degree of temperature decrease at both ends in the extension direction of the yarn contact surface was smaller than when brass was used as the heating element material (Comparative Example). In other words, the degree of temperature decrease at the yarn contact surface at positions farther from the control point was smaller in the Example than in the Comparative Example. This is because the thermal conductivity of aluminum is higher than that of brass, as will be described later.

[0058] Fig. 10 is a graph showing the power consumption when the heating elements according to the example and the comparative example are used and the set temperatures are 100°C, 200°C, and 300°C under no load (a state in which the yarn Y is not heated). As shown in Fig. 10, when aluminum is used as the material of the heating element as in the example, the power consumption is almost the same as when brass is used as the material of the heating element as in the comparative example.

[0059] (Physical properties of aluminum and brass) The table in Figure 11 shows the physical properties of the aluminum used as the material for the heating element in the example and the brass used as the material for the heating element in the comparative example in the above-mentioned comparative test, including melting point, specific heat, specific gravity, and thermal conductivity. Note that the physical properties of aluminum are at 20°C. The brass used is 73 brass, which has a zinc content of 30%. As shown in Figure 11, the melting point of aluminum is 660°C, which is lower than that of brass (1205°C). The specific heat of aluminum is 900 J / kg°C, which is higher than that of brass (385 J / kg°C). The specific gravity of aluminum is 2.7 g / cm 3 and brass (8.56 g / cm 3 ) The thermal conductivity of aluminum is 204 W / mk, which is higher than that of brass (99 W / mk).

[0060] (Features of the embodiment) As described above, the false twisting machine 1 of this embodiment is a false twisting machine 1 having a first heating device 13 that heats a running synthetic yarn Y. The first heating device 13 includes a heat source 51, a heating section 52 that is heated by the heat source 51, and a control device 100 that controls the temperature of the heat source 51. The heating section 52 includes a yarn contact section 54 that has a yarn contact surface 56 that comes into contact with the running yarn, and a heating element 53 that receives heat generated by the heat source 51 and heats the yarn contact section 54. The heating element 53 is made of a metal that contains aluminum, and the control device 100 controls the temperature of the heat source 51 so that the temperature of the heating element 53 is limited to 320°C or less.

[0061] According to the above-described configuration, the first heating device 13 is a contact type that heats the yarn Y by contacting the yarn contact surface 56, so the heating temperature can be lower than in the case of a non-contact type. That is, the yarn Y can be properly heated even when the temperature of the heating element 53 is 320°C or lower. Therefore, aluminum, which has a relatively low melting point, can be used as the material for the heating element 53. Because aluminum has a relatively high specific heat and a relatively low specific gravity, a certain degree of heat capacity can be ensured with a smaller mass than brass. This allows for cost reduction. Furthermore, because aluminum has a higher thermal conductivity than brass, the temperature of the heating element 53 in the yarn running direction can be maintained high.

[0062] Furthermore, in the false twisting machine 1 of this embodiment, the yarn contact section 54 extends in an extension direction that intersects at least the vertical direction, and the first heating device 13 is installed so that the yarn contact surface 56 faces at least downward and so that the inclination angle of the yarn contact surface 56 with respect to the horizontal direction is between -60° and +60° in a cross section parallel to both the vertical direction and the extension direction. Therefore, when a yarn breakage occurs, the yarn Y can be quickly separated from the yarn contact surface 56 by its own weight. This prevents the yarn Y from melting in the first heating device 13 and adhering to the first heating device 13 when a yarn breakage occurs.

[0063] Furthermore, in the false twisting machine 1 of this embodiment, the heat source 51 generates heat when an electric current is supplied to it. The heat source 51 is equipped with a sensor 57 that detects the temperature of the heating element 53, and a current supply circuit 58 that can supply an electric current to the heating wire of the heat source 51. The control device 100 controls the ON / OFF of the current supply circuit 58 based on the detection value of the sensor 57, switching between a state in which current is supplied to the heat source 51 and a state in which current is not supplied. Therefore, compared to when the magnitude of the current or voltage supplied to the heat source 51 is controlled, control can be simplified and costs can be reduced.

[0064] In addition, the false twisting machine 1 of this embodiment is equipped with a thermostat 70 that cuts off the current supplied to the heat source 51 when the temperature of the heating element 53 reaches an abnormal temperature of 400°C or higher and 450°C or lower. If the control device 100 is unable to control the temperature of the heating element 53 due to a malfunction of the sensor 57 or the like, the temperature of the heating element 53 may rise above the upper limit temperature. The heating element 53 of this embodiment is made of a metal containing aluminum. Here, the melting point of pure aluminum with a purity of 99% or higher is 660°C. The melting point of an Al-Cu-based aluminum alloy is 500°C to 640°C. The melting point of an Al-Mn-based aluminum alloy is 640°C. The melting point of an Al-Si-based aluminum alloy is 530°C to 570°C. The melting point of an Al-Mg-based aluminum alloy is 570°C to 650°C. The melting point of an Al-Mg-Si-based aluminum alloy is 580°C to 650°C. The melting point of an Al-Zn-Mg aluminum alloy is 480°C to 640°C. In this embodiment, when the temperature of the heating member 53 reaches an abnormal temperature of 400°C or higher and 450°C or lower, the thermostat 70 can cut off the current supplied to the heat source 51. This suppresses the temperature rise of the heating member 53 made of a metal containing aluminum, and prevents it from melting or approaching a melting state. This prevents the strength of the heating member 53 from decreasing.

[0065] Although the embodiments of the present invention have been described above with reference to the drawings, the specific configurations should not be considered to be limited to these embodiments. The scope of the present invention is defined by the claims rather than the above description of the embodiments, and further includes all modifications within the meaning and scope of the claims.

[0066] In the above embodiment, the case where the thermostat 70 cuts off the current supplied to the heat source 51 when the temperature of the heating member 53 reaches an abnormal temperature of 400°C or higher and 450°C or lower has been described, but the present invention is not limited to this. That is, a thermal fuse may be used instead of the thermostat 70. Also, a circuit breaker such as the thermostat 70 or a thermal fuse may not be provided.

[0067] Furthermore, in the above embodiment, the sensor 57 is disposed in the recess 52a formed across one end face in the height direction of the heating members 53a, 53b, and is disposed at a position overlapping the heat source 51 in the height direction. However, the positioning of the sensor 57 is not limited to this. For example, the sensor 57 may be disposed at a position aligned with the heat source 51 in the longitudinal direction of the machine base. The sensor 57 is preferably disposed near the heat source 51.

[0068] In the above embodiment, the first heating device 13 is described as being installed so that the yarn contact surface 56 faces at least downward and so that the inclination angle of the yarn contact surface 56 with respect to the horizontal direction is between -60° and +60° in a cross section parallel to both the vertical direction and the extending direction, but this is not limited to this. That is, the yarn contact surface 56 may face upward. Furthermore, the inclination angle of the yarn contact surface 56 with respect to the horizontal direction does not have to be between -60° and +60°.

[0069] Additionally, in the above embodiment, the present invention has been described as being applied to a false twisting machine 1 that applies false twisting to yarn Y, but the present invention is not limited to this. The present invention is not limited to false twisting, and can be applied to yarn processing machines that apply various processes, such as doubling, to yarns made of synthetic fibers. [Explanation of symbols]

[0070] 1. False twisting machine (yarn processing machine) 13 First heating device (heating device) 51 Heat source 52 Heating section 53 Heating element 54 Grafting section 56 Grafting surface 57 Sensors 58 Current supply circuit 70 Thermostat (circuit breaker) 100 control device (control unit)

Claims

1. A yarn processing machine having a heating device for heating a running yarn made of synthetic fiber, the heating device includes a heat source, a heating unit heated by the heat source, and a control unit that controls the temperature of the heat source; The heating unit is a yarn contact portion provided with a yarn contact surface for contacting the running yarn; a heating member for receiving heat generated by the heat source and heating the yarn contact portion, the heating element is made of a metal containing aluminum, The control unit controlling the temperature of the heat source so that the temperature of the heating element is limited to 320°C or less; The yarn contact portion extends in an extension direction that intersects at least the vertical direction, The heating device is installed so that the yarn contact surface faces at least downward and so that the inclination angle of the yarn contact surface with respect to the horizontal direction is between −60° and +60° in a cross section parallel to both the vertical direction and the extension direction.

2. the heat source generates heat when an electric current is supplied thereto; a sensor for detecting the temperature of the heating element; a current supply circuit capable of supplying current to the heat source, 2. The yarn processing machine according to claim 1, wherein the control unit controls the current supply circuit based on the detection value of the sensor to switch between a state in which current is supplied to the heat source and a state in which current is not supplied.

3. 3. The yarn processing machine according to claim 2, further comprising a circuit breaker that cuts off the current supplied to the heat source when the temperature of the heating element reaches a predetermined temperature of 400°C or higher and 450°C or lower.

4. A yarn processing machine having a heating device for heating a running yarn made of synthetic fiber, the heating device includes a heat source, a heating unit heated by the heat source, and a control unit that controls the temperature of the heat source; the heat source generates heat when an electric current is supplied thereto; The heating unit is a yarn contact portion provided with a yarn contact surface for contacting the running yarn; a heating member for receiving heat generated by the heat source and heating the yarn contact portion, the heating element is made of a metal containing aluminum, the control unit controls the temperature of the heat source so that the temperature of the heating element is limited to 320°C or less; a sensor for detecting the temperature of the heating element; a current supply circuit capable of supplying current to the heat source, The control unit controls the current supply circuit based on the detection value of the sensor, switching between a state in which current is supplied to the heat source and a state in which current is not supplied, and when the detection value of the sensor rises to a predetermined upper temperature limit of 320°C or less, the control unit switches to a state in which current is not supplied to the heat source, thereby lowering the temperature of the heat source.

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