Draft ratio setting device and spinning machine in a spinning machine

Abstract

To provide a draft ratio setting device of a fine spinning machine and a fine spinning machine that can suppress changes in a total draft ratio and a number of twists of a yarn regardless of attaching and detaching of a compact part that makes a tension draft ratio become variable.SOLUTION: In a control part 31, attaching of a compact part 16 is detected by a detector 51, then a speed control part 52 controls a rotational speed of a delivery bottom roller 15a to a rotational speed of a front bottom roller 12a before attaching the compact part 16 and conducts control of changing the rotational speed of the front bottom roller 12a in accordance with changes of a tension draft ratio. When detaching of the compact part 16 is detected by the detector 51, the speed control part 52 controls the rotational speed of the front bottom roller 12a to the rotational speed of the delivery bottom roller 15a on attaching the compact part 16.SELECTED DRAWING: Figure 2

Description

Technical Field

[0005] , , ,

[0001] The present invention relates to a draft ratio setting device and a spinning frame in a spinning machine.

Background Art

[0002] For example, Patent Document 1 discloses a draft mechanism for a spinning machine in which a drafting unit as a compact device is removably attached. The draft mechanism of Patent Document 1 includes four bottom rollers. Three of the four bottom rollers are supported by the same support portion. The remaining one of the four bottom rollers constitutes a drafting unit. Thereby, the drafting unit is configured to be removable or attachable to the three bottom rollers. <000s010>

[0003] When the drafting unit is attached, the supplied sliver is drafted by passing through three roller pairs. Further, it is drafted by the roller pair of the drafting unit. When the drafting unit is removed, in order to suppress a decrease in yarn quality, the three roller pairs are each moved in the traveling direction of the sliver. Thereby, the traveling length of the sliver is made the same as when the drafting unit is attached.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] When the rotational speed of the bottom roller of the drafting unit is different from the rotational speed of the immediately preceding bottom roller, the total draft ratio of the draft mechanism and the twist number of the yarn change before and after the attachment of the drafting unit.

Means for Solving the Problems

[0006] A draft ratio setting device for a spinning machine to solve the above problems comprises: a draft section in which a front roller can be driven independently of a middle roller and a back roller; a compact section in which a delivery roller is attached downstream of the front roller and can be driven independently of the front roller, and which can change the tension draft ratio between the front roller and the delivery roller; and a speed control section that controls the rotational speed of the front roller, the middle roller, the back roller, and the delivery roller. The device further comprises a detection section for detecting the attachment and removal of the compact section. When the detection section detects the attachment of the compact section, the speed control section controls the rotational speed of the delivery roller to the rotational speed of the front roller before the attachment of the compact section, and also controls the rotational speed of the front roller in accordance with the change in the tension draft ratio. When the detection section detects the removal of the compact section, the speed control section controls the rotational speed of the front roller to the rotational speed of the delivery roller when the compact section is attached.

[0007] A spinning machine to solve the above problems comprises a draft section in which a front roller can be driven independently of a middle roller and a back roller; a compact section attached downstream of the front roller and including a deliverer roller that can be driven independently of the front roller, and capable of changing the tension draft ratio between the front roller and the deliverer roller; a speed control section that controls the rotational speed of the front roller, the middle roller, the back roller, and the deliverer roller, and a draft ratio setting device, wherein the draft ratio setting device comprises a detection section that detects the attachment and removal of the compact section, and when the attachment of the compact section is detected by the detection section, the speed control section controls the rotational speed of the deliverer roller to the rotational speed of the front roller before the attachment of the compact section and controls the rotational speed of the front roller in accordance with the change in the tension draft ratio, and when the removal of the compact section is detected by the detection section, the speed control section controls the rotational speed of the front roller to the rotational speed of the deliverer roller when the compact section is attached.

[0008] According to these instructions, when the compact unit is installed, the speed control unit sets the rotation speed of the delivery roller to the rotation speed of the front roller before the compact unit was installed. As a result, the delivery roller becomes the final delivery roller with the same rotation speed as before the compact unit was installed. Furthermore, even if the tension draft ratio is changed by the installation of the compact unit, the speed control unit changes the rotation speed of the front roller. Therefore, by not changing the spindle rotation speed, it is possible to prevent the total draft ratio and the number of twists in the drafted yarn from changing from before the compact unit was installed, even if the tension draft ratio is changed by the installation of the compact unit.

[0009] Furthermore, when the compact unit is removed, the speed control unit sets the rotation speed of the front roller to the rotation speed of the delivery roller when the compact unit was installed. As a result, the front roller becomes the final delivery roller with the same rotation speed as when the compact unit was installed. And because the compact unit is removed, the total draft ratio returns to what it was before the compact unit was installed. Therefore, as long as the spindle rotation speed is not changed, even if the compact unit is removed, it is possible to suppress changes in the total draft ratio and the number of twists in the drafted yarn after the compact unit is removed.

[0010] Regarding the draft ratio setting device in a spinning machine, when the detection unit detects the installation of the compact unit, the speed control unit may change the main draft ratio of the draft unit while keeping the brake draft ratio of the draft unit the same as before the installation of the compact unit.

[0011] According to this, the brake draft ratio significantly affects the quality of the drafted yarn. By not changing this brake draft ratio, the installation or removal of the compact unit can be suppressed from affecting the quality of the drafted yarn.

[0012] Regarding the draft ratio setting device in a spinning machine, when the detection unit detects the installation of the compact unit, the speed control unit may change the brake draft ratio of the draft unit while keeping the main draft ratio of the draft unit the same as before the installation of the compact unit.

[0013] According to this, the yarn can be optimally drafted between the front roller and the middle roller. Regarding the draft ratio setting device in a spinning machine, when the tension draft ratio is changed, the speed control unit may control the rotation speed of the front roller in accordance with the change in the tension draft ratio, while keeping the total draft ratio the same as before the change in the tension draft ratio.

[0014] According to this, when changing the tension draft ratio in the draft of the yarn after the compact part is attached, the speed control unit changes the rotational speed of the front roller without changing the rotational speed of the delivery roller. Therefore, it is possible to draft without changing the twist number of the yarn.

Effect of the Invention

[0015] The present invention can suppress changes in the total draft ratio and the twist number of the yarn regardless of the attachment and detachment of the compact part with a variable tension draft ratio.

Brief Description of the Drawings

[0016] [Figure 1] FIG. \ 1 is a schematic diagram showing a draft part before the attachment of the compact part. [Figure 2] FIG. \ 2 is a schematic diagram showing a draft part at the time of attachment of the compact part. [Figure 3] FIG. \ 3 is a cross - sectional view showing a draft part before the attachment of the compact part. [Figure 4] FIG. \ 4 is a cross - sectional view showing a draft part at the time of attachment of the compact part. [Figure 5] FIG. \ 5 is a table showing the relationship between the draft ratio and the rotational speed. [Figure 6] FIG. \ 6 is a table showing the relationship between the draft ratio and the rotational speed in another example.

Mode for Carrying Out the Invention

[0017] Hereinafter, an embodiment in which a draft ratio setting device and a spinning machine of a spinning machine are embodied will be described according to FIGS. \ 1 to 5. <Spinning machine> As shown in FIGS. \ 1 and 2, the spinning machine 10 includes a draft device 11 and a control device 31 as a draft ratio setting device. Further, as shown in FIGS. \ 3 and 4, the spinning machine 10 includes a spindle drive unit 40 and a lifting drive unit (not shown).

[0018] <Spindle drive unit> The spindle drive unit 40 winds up the yarn drafted by the drafting device 11. The spindle drive unit 40 includes a spindle 41 that rotates a bobbin 42 for winding up the yarn, and a spindle motor 43 that rotates the spindle 41.

[0019] <Drafting device> As shown in FIGS. 1 and 2, the drafting device 11 can have a three-line configuration including a drafting section 17 composed of a front roller pair 12, a middle roller pair 13, and a back roller pair 14, and a four-line configuration with a delivery roller pair 15 added.

[0020] As shown in FIGS. 1 and 3, in the drafting section 17, the front roller pair 12 includes a front bottom roller 12a and a front top roller 12b. In the drafting section 17, the middle roller pair 13 includes a middle bottom roller 13a and a middle top roller 13b, and also includes a middle apron 13c. In the drafting section 17, the back roller pair 14 includes a back bottom roller 14a and a back top roller 14b.

[0021] As shown in FIGS. 2 and 4, the delivery roller pair 15 includes a delivery bottom roller 15a, a delivery top roller 15b, and a delivery apron 15c. The compact section 16 is composed of the delivery bottom roller 15a, the delivery top roller 15b, the delivery apron 15c, a suction pipe 18, and a guide member 19. And the compact section 16 is attached on the downstream side of the front bottom roller 12a and the front top roller 12b.

[0022] As shown in Figures 1 and 2, the front bottom roller 12a is driven by the front roller drive motor 21. The middle bottom roller 13a is driven by the middle roller drive motor 22. The back bottom roller 14a is driven by the back roller drive motor 23. The delivery bottom roller 15a is driven by the delivery roller drive motor 24. Therefore, each bottom roller 12a, 13a, 14a, and 15a can be driven independently. Furthermore, the front bottom roller 12a can be driven independently of the middle bottom roller 13a and the back bottom roller 14a. Thus, in the draft section 17, the front bottom roller 12a can be driven independently of the middle bottom roller 13a and the back bottom roller 14a. In addition, the compact section 16 is mounted downstream of the front bottom roller 12a and includes a delivery bottom roller 15a that can be driven independently of the front bottom roller 12a.

[0023] Each of the drive motors 21, 22, 23, and 24 is a servo motor. Each of the drive motors 21, 22, 23, and 24 is connected to drivers 21a, 22a, 23a, and 24a. Each of the drive motors 21, 22, 23, and 24 is controlled by the control device 31 via drivers 21a, 22a, 23a, and 24a.

[0024] In the drafting device 11, the rotational speed ratio between the back bottom roller 14a and the middle bottom roller 13a is the brake draft ratio. The rotational speed ratio between the middle bottom roller 13a and the front bottom roller 12a is the main draft ratio. The rotational speed ratio between the front bottom roller 12a and the delivery bottom roller 15a is the tension draft ratio. Furthermore, in the drafting device 11 including the compact section 16, the tension draft ratio can be changed by changing the rotational speed ratio between the delivery roller drive motor 24 and the front roller drive motor 21.

[0025] In the drafting device 11 with the compact section 16 removed, the total draft ratio of the entire drafting device 11 is determined from the brake draft ratio and the main draft ratio. Then, in order to obtain a normal yarn of the desired yarn count and twist count, the total draft ratio and the rotation speed of the front bottom roller 12a are set, and the brake draft ratio and the main draft ratio are set. Therefore, in the drafting device 11 with the compact section 16 removed, roving can be drafted into normal yarn. If the total draft ratio is not changed, the brake draft ratio and the main draft ratio can be adjusted as appropriate. In addition, the rotation speed of the spindle 41 in the spindle drive unit 40 is set. The rotation speed of the spindle 41 is controlled by the drive of the spindle motor 43 controlled by a driver (not shown).

[0026] Meanwhile, in the drafting device 11 to which the compact section 16 is attached, the total draft ratio of the entire drafting device 11 is determined from the brake draft ratio, the main draft ratio, and the tension draft ratio. In order to obtain a compact yarn of the desired yarn count and twist count, the total draft ratio and the rotation speed of the delivery bottom roller 15a are set, and the brake draft ratio, main draft ratio, and tension draft ratio are also set. Therefore, in the drafting device 11 to which the compact section 16 is attached, roving can be drafted into compact yarn. If the total draft ratio is not changed, the brake draft ratio, main draft ratio, and tension draft ratio can be adjusted as appropriate. In addition, the rotation speed of the spindle 41 in the spindle drive unit 40 is set.

[0027] When the compact section 16 is removed, the drafting device 11 drafts the roving into ordinary yarn. In this ordinary yarn drafting, a total draft ratio suitable for the ordinary yarn draft is set, and the brake draft ratio and main draft ratio are set to achieve that total draft ratio.

[0028] Furthermore, when the compact section 16 is attached, the drafting device 11 drafts the roving into compact yarn. Compact yarn is a yarn with a higher yarn count than ordinary yarn. In other words, compact yarn is a yarn with improved yarn quality compared to ordinary yarn.

[0029] In compact yarn drafting, a total draft ratio suitable for compact yarn drafting is set, and the brake draft ratio, main draft ratio, and tension draft ratio are each set to achieve that total draft ratio.

[0030] <Control device> The control device 31 comprises a storage unit 32, a detection unit 51, a speed control unit 52, and a display control unit 53.

[0031] The control unit 31 may include, for example, a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a DSP (Digital Signal Processor). The storage unit 32 includes RAM (Random Access Memory) and ROM (Read Only Memory). The storage unit 32 stores program code or instructions configured to cause the control unit 31 to execute processing. The storage unit 32, i.e., the computer-readable medium, includes any available medium that can be accessed by a general-purpose or dedicated computer. The control unit 31 may be composed of hardware circuits such as an ASIC (Application Specific Integrated Circuit) or an FPGA (Field Programmable Gate Array). The control unit 31, which is a processing circuit, may include one or more processors that operate according to a computer program, one or more hardware circuits such as an ASIC or FPGA, or a combination thereof.

[0032] The control device 31 is electrically connected to the input device 25 via the input interface 34. The input device 25 is where the operator performs various setting operations. Examples of input devices 25 include physical icons, dials, keyboards, and styluses.

[0033] The control device 31 is electrically connected to the compact unit 16 via the input interface 34. The control device 31 is connected to drivers 21a, 22a, and 23a via an output interface 35 and a motor drive circuit (not shown). The control device 31 is also connected to driver 24a via an output interface 35 and a motor drive circuit (not shown). The control device 31 is connected to a display device 26 via an output interface 35. The display device 26 is a liquid crystal display or the like. The display device 26 displays various setting information of the drafting device 11, such as the presence or absence of the compact section 16, the yarn count, the number of twists, and various draft ratios.

[0034] The speed control unit 52 controls the rotational speed of the front bottom roller 12a, middle bottom roller 13a, back bottom roller 14a, and delivery bottom roller 15a. The control device 31 controls a motor (not shown) that drives the lifting drive unit, as well as the spindle motor 43 of the spindle drive unit 40.

[0035] The detection unit 51 detects the electrical connection of the compact unit 16 to the input interface 34 and the electrical disconnection of the compact unit 16 based on the manually entered information from the input device 25. When the detection unit 51 detects the electrical connection of the compact unit 16 based on the manually entered information from the input device 25, it outputs a connection detection signal to the speed control unit 52. Also, when the detection unit 51 detects the electrical disconnection of the compact unit 16 based on the manually entered information from the input device 25, it outputs a disconnection detection signal to the speed control unit 52.

[0036] When the compact unit 16 is connected to the input interface 34 and a connection detection signal is input to the speed control unit 52, the speed control unit 52 sets the rotational speed of the delivery roller drive motor 24 to the same as the rotational speed of the front roller drive motor 21 before the installation of the compact unit 16. In other words, when the installation of the compact unit 16 is detected, the speed control unit 52 controls the rotational speed of the delivery bottom roller 15a to the rotational speed of the front bottom roller 12a before the installation of the compact unit 16. As a result, the delivery roller pair 15 can function as the final delivery roller pair in the drafting device 11, just as it did before the installation of the compact unit 16.

[0037] On the other hand, in the draft device 11, a tension draft ratio is generated by the addition of the delivery roller pair 15. If the tension draft ratio is "1" or "approximately 1", the total draft ratio does not change before and after the installation of the compact section 16, even if the delivery roller pair 15 is added.

[0038] However, if the tension draft ratio is set to a value other than "1", the rotational speed of the front bottom roller 12a and the delivery bottom roller 15a will be different before the compact section 16 is installed. As a result, the total draft ratio of the draft device 11 will change from before the compact section 16 is installed.

[0039] If the tension draft ratio is set to a value other than "1", the speed control unit 52 controls the main draft ratio in order to make the total draft ratio the same as before the installation of the compact unit 16. In other words, in order to make the total draft ratio of the draft device 11 the same as before the installation of the compact unit 16, the speed control unit 52 controls the rotation speed of the front bottom roller 12a in accordance with the change in the tension draft ratio to a value other than "1". The speed control unit 52 compensates for the change in the total draft ratio caused by the occurrence of the tension draft ratio by changing the main draft ratio. In other words, the speed control unit 52 controls the rotation speed of the front bottom roller 12a so that the change in the total draft ratio is offset. The speed control unit 52 controls the driver 21a of the front roller drive motor 21 to control the rotation speed of the front bottom roller 12a. The rotation speed of the delivery roller drive motor 24 and the rotation speed of the front bottom roller 12a set by the speed control unit 52 are temporarily stored in the storage unit 32. Therefore, in this case, the main draft ratio of the draft device 11 is changed while keeping the brake draft ratio of the draft device 11 the same as before the installation of the compact section 16.

[0040] Furthermore, in the drafting device 11 including the compact section 16, the tension draft ratio can be changed. Even in this case, in order to keep the total draft ratio constant, the speed control unit 52 controls the rotational speed of the front bottom roller 12a. Note that the rotational speeds of the delivery bottom roller 15a, the middle bottom roller 13a, and the back bottom roller 14a are not changed and remain constant.

[0041] In the table in Figure 5, the tension draft ratio, the rotational speed of the front bottom roller 12a, and the main draft ratio before changing the tension draft ratio are considered the "reference." In Figure 5, the front bottom roller 12a is referred to as the front roller. Similarly, the middle bottom roller 13a is referred to as the middle roller, the back bottom roller 14a as the back roller, and the delivery bottom roller 15a as the delivery roller.

[0042] When increasing the tension draft ratio, in order to maintain the same total draft ratio, the rotational speed of the front bottom roller 12a is set to decrease compared to before the tension draft ratio was changed, thereby reducing the main draft ratio.

[0043] Conversely, when reducing the tension draft ratio, the rotation speed of the front bottom roller 12a is set to increase compared to before the tension draft ratio change, in order to increase the main draft ratio so as not to change the total draft ratio. In other words, when the tension draft ratio is changed, the speed control unit 52 controls the rotation speed of the front bottom roller 12a in accordance with the change in the tension draft ratio, while keeping the total draft ratio the same as before the change.

[0044] The rotational speed of the front bottom roller 12a, as set in this manner, is temporarily stored in the memory unit 32. When the spinning machine 10 is operated, the speed control unit 52 retrieves the rotational speeds stored in the memory unit 32 and outputs them to the driver 21a. The driver 21a then controls the front roller drive motor 21 to drive at the set rotational speed. The rotational speeds of the middle bottom roller 13a and the back bottom roller 14a remain unchanged.

[0045] When the detection unit 51 detects the electrical disconnection of the compact unit 16 based on manual input information from the input device 25, it outputs a disconnection detection signal to the speed control unit 52. When the speed control unit 52 receives the disconnection detection signal, it sets the rotational speed of the front roller drive motor 21 to the same as the rotational speed of the delivery roller drive motor 24 before the compact unit 16 was installed. In other words, when the detection unit 51 detects the removal of the compact unit 16, the speed control unit 52 controls the rotational speed of the front bottom roller 12a to change it to the rotational speed of the delivery bottom roller 15a before the compact unit 16 was installed. As a result, the front roller pair 12 becomes the same final delivery roller pair in the draft device 11 as before the compact unit 16 was installed. The rotational speed of the front bottom roller 12a set by the speed control unit 52 is then temporarily stored in the storage unit 32. At the same time, the total draft ratio is changed to the ratio before the compact unit 16 was installed.

[0046] When the spinning machine 10 is operated with the compact unit 16 attached or detached, the speed control unit 52 acquires the rotational speed stored in the memory unit 32 and outputs it to the driver 21a. The driver 21a then controls the front roller drive motor 21 to drive at the set rotational speed.

[0047] Furthermore, the tension draft ratio may be changed while the compact section 16 is installed. In this case, when the changed tension draft ratio is input from the input device 25, the speed control unit 52 changes the rotational speed of the front roller drive motor 21. The rotational speed of the front roller drive motor 21 is changed to alter the main draft ratio so that the total draft ratio does not change even if the tension draft ratio is changed. For example, when increasing the tension draft ratio, the main draft ratio is decreased so that the total draft ratio does not change. To decrease the main draft ratio, the rotational speed of the front bottom roller 12a is reduced compared to before the change.

[0048] Conversely, when reducing the tension draft ratio, the main draft ratio is increased so that the total draft ratio does not change. To increase the main draft ratio, the rotational speed of the front bottom roller 12a is increased compared to before the change.

[0049] When the compact unit 16 is electrically connected, the display control unit 53 displays information related to the installation of the compact unit 16 on the display device 26. Furthermore, when the electrical connection to the compact unit 16 is disconnected, the display control unit 53 displays information that the compact unit 16 has been removed on the display device 26.

[0050] <Drafting with regular yarn> Prior to the operation of the spinning machine 10, spinning conditions such as the fiber raw material, the yarn count for ordinary yarn, and the number of twists are input via the input device 25. These spinning conditions are then input to the control device 31. When the spinning machine 10 starts operating, based on commands from the control device 31, the drive motors 21, 22, and 23 are controlled via drivers 21a, 22a, and 23a to rotate at rotational speeds corresponding to the total draft ratio, main draft ratio, and brake draft ratio, which are preset in accordance with the spinning conditions. In addition, the spindle motor 43 of the spindle drive unit 40 and the drive motor of the lifting system are also controlled to rotate at predetermined rotational speeds.

[0051] The roving is then drafted through the back roller pair 14, middle roller pair 13, and front roller pair 12 of the drafting device 11. The ordinary yarn is sent out using the front roller pair 12 as the final feed roller pair, and then wound onto a bobbin 42 which rotates integrally with the spindle 41 in the spindle drive unit 40. This produces ordinary yarn with the set yarn count, twist count, etc.

[0052] <Compact yarn draft> When drafting compact yarn, the spinning conditions, such as the fiber raw materials, yarn count, and number of twists, are the same as for ordinary yarn.

[0053] Prior to the operation of the spinning machine 10, the compact unit 16 is mechanically attached to the machine base to form a draft device 11 including the compact unit 16. Based on the manually input information from the input device 25, the detection unit 51 detects the electrical connection of the compact unit 16 to the input interface 34 and outputs a connection detection signal. When the connection detection signal is input to the speed control unit 52, the speed control unit 52 sets the rotational speed of the delivery roller drive motor 24 to be the same as the rotational speed of the front roller drive motor 21 before the compact unit 16 was attached.

[0054] When the spinning machine 10 starts operation, based on commands from the control device 31, the drive motors 21, 22, 23, and 24 are controlled via drivers 21a, 22a, 23a, and 24a to rotate at rotational speeds corresponding to the preset tension draft ratio, total draft ratio, main draft ratio, and brake draft ratio, which are determined according to the spinning conditions. In addition, the drive motors of the spindle drive unit 40 and the lifting system are also controlled to rotate at predetermined rotational speeds.

[0055] The roving is then drafted through the back roller pair 14, middle roller pair 13, front roller pair 12, and delivery roller pair 15 of the drafting device 11. After the delivery roller pair 15 is used as the final delivery roller pair, the roving is wound onto a bobbin 42, which rotates integrally with the spindle 41, in the spindle drive unit 40. This produces a compact yarn with the set yarn count, twist count, etc.

[0056] According to the above embodiment, the following effects can be obtained. (1) When the roving to be drafted by the drafting device 11 is changed from ordinary yarn to compact yarn, the speed control unit 52 sets the rotation speed of the delivery bottom roller 15a to the rotation speed of the front bottom roller 12a before the compact section 16 is installed. As a result, the delivery bottom roller 15a becomes the final delivery roller with the same rotation speed as before the compact section 16 was installed. Furthermore, even if the tension draft ratio is changed by the compact section 16, the speed control unit 52 changes the rotation speed of the front bottom roller 12a. As a result, even if the tension draft ratio is changed by the installation of the compact section 16, it is possible to prevent the total draft ratio and the number of twists in the drafted compact yarn from changing from before the installation of the compact section 16.

[0057] (2) When the roving to be drafted by the drafting device 11 is changed from compact yarn to ordinary yarn, the speed control unit 52 sets the rotation speed of the front bottom roller 12a to the rotation speed of the delivery bottom roller 15a. As a result, the front bottom roller 12a becomes the final delivery roller with the same rotation speed as when the compact section 16 was installed. And since the compact section 16 is removed, the total draft ratio returns to the level before the compact section 16 was installed. Therefore, even if the compact section 16 is removed, it is possible to suppress changes in the total draft ratio and the number of twists in the drafted ordinary yarn after the removal of the compact section 16.

[0058] (3) When the compact section 16 is connected and a connection detection signal is input to the control device 31, the speed control unit 52 changes the main draft ratio without changing the brake draft ratio. Since the brake draft ratio is a factor that greatly affects yarn quality, it is possible to change from ordinary yarn to compact yarn without changing the yarn quality.

[0059] (4) When changing the tension draft ratio in the draft of compact yarn, the speed control unit 52 changes the rotation speed of the front bottom roller 12a without changing the rotation speed of the delivery bottom roller 15a. Therefore, compact yarn can be drafted without changing the total draft ratio and the number of twists.

[0060] (5) When the speed control unit 52 detects the attachment or removal of the compact unit 16 by the detection unit 51, it controls the rotation speed of the front bottom roller 12a and the delivery bottom roller 15a. Therefore, by attaching or detaching the compact unit 16, the type of yarn being drafted can be easily switched between ordinary yarn and compact yarn.

[0061] This embodiment can be implemented with the following modifications. This embodiment and the following modifications can be combined with each other to the extent that they do not contradict each other technically. ○When the compact section 16 is installed, if the tension draft ratio is changed by changing the rotational speed of the front bottom roller 12a, the speed control unit 52 may change the rotational speed of the middle roller drive motor 22. In this case, as shown in Figure 6, the brake draft ratio is changed so that the total draft ratio does not change even if the tension draft ratio is changed. Note that in Figure 6, the front bottom roller 12a is referred to as the front roller. The middle bottom roller 13a is referred to as the middle roller, the back bottom roller 14a is referred to as the back roller, and the delivery bottom roller 15a is referred to as the delivery roller.

[0062] For example, when increasing the tension draft ratio, the brake draft ratio is decreased so that the total draft ratio does not change. To decrease the brake draft ratio, the rotational speed of the middle bottom roller 13a is reduced compared to before the change.

[0063] Conversely, when reducing the tension draft ratio, the brake draft ratio is increased to ensure that the total draft ratio remains unchanged. To increase the brake draft ratio, the rotational speed of the middle bottom roller 13a is increased compared to before the change.

[0064] According to this, if the rotation speed of the front bottom roller 12a is changed to alter the tension draft, the yarn can be optimally drafted between the front roller pair 12 and the middle roller pair 13.

[0065] ○When the detection unit 51 detects the installation of the compact unit 16, the speed control unit 52 may control the drafting device 11 to change the brake draft ratio while keeping the main draft ratio of the drafting device 11 the same as before the installation of the compact unit 16. This allows the yarn to be optimally drafted between the front bottom roller 12a and the middle bottom roller 13a.

[0066] ○When changing the roving to be drafted from ordinary yarn to compact yarn, the speed control unit 52 may change both the main draft ratio and the brake draft ratio in order to prevent the total draft ratio from changing. In this case, the speed control unit 52 adjusts the rotation speed of the front bottom roller 12a and the middle bottom roller 13a.

[0067] ○The attachment or removal of the compact unit 16 to the draft device 11 may be detected by a detection unit such as a sensor that detects the presence or absence of the compact unit 16, or by a detection unit that detects the electrical connection of the delivery roller drive motor 24 or the suction device motor.

[0068] ○The installation or removal of the compact unit 16 does not need to be displayed on the display device 26. The rollers driven by each drive motor 21, 22, 23, 24 may be the top rollers 12b, 13b, 14b, 15b.

[0069] ○The middle roller pair 13 and the back roller pair 14 do not necessarily have to be able to be driven independently of each other. [Explanation of Symbols]

[0070] 10...Spinning machine, 12a...Front bottom roller, 12b...Front top roller, 13a...Middle bottom roller, 13b...Middle top roller, 14a...Back bottom roller, 14b...Back top roller, 15a...Delivery bottom roller, 15b...Delivery top roller, 16...Compact section, 17...Draft section, 31...Control device as draft ratio setting device, 51...Detection section, 52...Speed ​​control section.

Claims

1. A draft section in which the front roller can be driven independently of the middle roller and the back roller, A compact section is provided which includes a delivery roller mounted downstream of the front roller and capable of being driven independently of the front roller, and which can change the tension draft ratio between the front roller and the delivery roller. A draft ratio setting device for a spinning machine, comprising a speed control unit for controlling the rotational speed of the front roller, the middle roller, the back roller, and the delivery roller, The system includes a detection unit for detecting the attachment and removal of the compact unit, When the detection unit detects the installation of the compact unit, the speed control unit controls the rotation speed of the delivery roller to the rotation speed of the front roller before the installation of the compact unit, and also controls the rotation speed of the front roller in accordance with the change in the tension draft ratio. A draft ratio setting device for a spinning machine, characterized in that when the detection unit detects the removal of the compact unit, the speed control unit controls the rotation speed of the front roller to change it to the rotation speed of the delivery roller when the compact unit is installed.

2. The draft ratio setting device for a spinning machine according to claim 1, wherein when the detection unit detects the installation of the compact unit, the speed control unit changes the main draft ratio of the draft unit while keeping the brake draft ratio of the draft unit the same as before the installation of the compact unit.

3. The draft ratio setting device for a spinning machine according to claim 1, wherein when the detection unit detects the installation of the compact unit, the speed control unit changes the brake draft ratio of the draft unit while keeping the main draft ratio of the draft unit the same as before the installation of the compact unit.

4. A draft ratio setting device for a spinning machine according to any one of claims 1 to 3, wherein when the tension draft ratio is changed, the speed control unit controls the rotation speed of the front roller in accordance with the change in the tension draft ratio, while keeping the total draft ratio the same as before the change in the tension draft ratio.

5. A draft section in which the front roller can be driven independently of the middle roller and the back roller, A compact section is provided which includes a delivery roller mounted downstream of the front roller and capable of being driven independently of the front roller, and which can change the tension draft ratio between the front roller and the delivery roller. A spinning machine comprising a speed control unit for controlling the rotational speed of the front roller, the middle roller, the back roller, and the delivery roller, and having a draft ratio setting device, The draft ratio setting device is, The system includes a detection unit for detecting the attachment and removal of the compact unit, When the detection unit detects the installation of the compact unit, the speed control unit controls the rotation speed of the delivery roller to the rotation speed of the front roller before the installation of the compact unit, and also controls the rotation speed of the front roller in accordance with the change in the tension draft ratio. The spinning machine is characterized in that, when the detection unit detects the removal of the compact unit, the speed control unit controls the rotation speed of the front roller to change it to the rotation speed of the delivery roller when the compact unit is attached.

Images