JP5813975B2 - Flat knitting machine - Google Patents

Description

  The present invention relates to a flat knitting machine, and more particularly to a safety mechanism when a carriage is stopped due to yarn breakage or the like.

  A flat knitting machine uses a servomotor to move the carriage. The flat knitting machine energizes and energizes the windings of the servo motor with the built-in servo driver, and rotates the servo motor in response to a servo command from the servo driver. The rotation speed of the servo motor or the position of the carriage is monitored by a sensor and fed back to the servo driver. When yarn breakage or the like occurs, the operator stops the flat knitting machine and performs operations such as manually connecting yarns. At this time, it is preferable that the joints come to an inconspicuous position such as the end of the knitting width. Therefore, for example, the knitting may be once knitted to the end of the knitting width, and then the carriage may be manually moved to reconnect the yarn so that the joint is at the end of the knitting width. When the excitation of the servo motor is turned off, the carriage can be slid along the needle bed.

By the way, the flat knitting machine may be provided with a member that can move in one direction but cannot move in the opposite direction, such as a stitch presser. The stitch presser can freely move into and out of the mouth, and is a member that facilitates knitting by pressing the knitted fabric when it moves into the mouth and is provided on the carriage (see Patent Document 1: WO2007 / 58272) ). Here, if the carriage is manually moved in a direction in which it cannot be moved in order to connect the yarn while the stitch presser has advanced, the stitch presser may be damaged or the knitted fabric may be damaged. .

WO2007 / 58272

  An object of the present invention is to enable an operator to manually move a carriage without causing damage to a member of a flat knitting machine and damage to a knitted fabric when excitation of a servo motor is turned off. It is in.

The present invention relates to a flat knitting machine in which a carriage for operating at least a pair of needle bed needles is moved by a servo motor along the longitudinal direction of the needle bed.
A dynamic brake configured by short-circuiting a plurality of windings included in the servo motor via a switch and a resistor;
A sensor for detecting the movement of the carriage;
When the excitation of the servo motor is turned off, the carriage movement is determined based on the carriage movement direction obtained from the sensor signal and the state of the other flat knitting machine mechanism. And a controller for turning on or off the dynamic brake according to whether or not it is possible.

  The state of the mechanism of the flat knitting machine is determined from the output of a sensor that monitors the state of each member of the flat knitting machine, the control data for controlling these members, the knitting data that is the basis of the control data, etc., and preferably the mechanism The state includes the moving direction of the carriage.

In this invention, when the flat knitting machine is stopped due to yarn breakage or the like, and as a result, the excitation of the servo motor is turned off, the movement of the carriage is controlled by the dynamic brake. Whether or not the carriage can be moved is determined based on the state of the mechanism of the flat knitting machine, and for this determination, the movement direction of the carriage and the state of the other flat knitting machine mechanism are used. Then , the dynamic brake is turned on or off according to whether the carriage can move. Therefore, if the carriage is moved manually when the movement is impossible, a large braking force is applied from the dynamic brake. If the carriage can be moved, the dynamic brake is turned off and the carriage can be moved manually. For these reasons, troubles in flat knitting machines such as yarn breakage can be dealt with by manually moving the carriage and forcibly moving the carriage in a state where movement is impossible, causing damage to members or knitting fabrics. Does not cause scratches.

According to the present invention, the flat knitting machine includes a sensor for detecting the movement of the carriage, and obtains the moving direction of the carriage from the signal of the sensor. Preferably, the carriage is advanced and retracted into the mouth of the tooth bed between at least a pair of needle beds, and can move in one direction along the longitudinal direction of the needle bed when advanced into the tooth mouth. A stitch presser that cannot move in the opposite direction along the longitudinal direction of the needle bed and that can move in any direction along the longitudinal direction of the needle bed when retracted from the mouth is provided. Whether the stitch presser has advanced or retracted into the mouth is set as the stitch presser state, which is a main example of the state of the mechanism of the flat knitting machine. When the controller is related to the state of the stitch presser, the stitch presser has advanced into the mouth and the carriage movement direction obtained from the sensor signal is a direction in which the stitch presser can be moved. Alternatively, when the stitch presser is retracted from the mouth, it is determined that the carriage can be moved, and in other cases, the carriage is determined not to be movable.

  If it does in this way, a stitch presser moves to the direction which cannot move, and a stitch presser will not be damaged or a knitted fabric will not be damaged.

More preferably, the state of the mechanism of the flat knitting machine further includes a state of the carriage whether or not the carriage is being selected.
  The controller
  The carriage can be moved in relation to the state of the stitch presser,
  The carriage can be moved when the needle is not selected and when the carriage is selected and the carriage movement direction obtained from the sensor signal matches the knitting direction until the servo motor excitation is turned off. Judging
  In other cases, it is determined that the carriage cannot be moved.
  In this way, the needle does not follow an unexpected trajectory within the carriage cam.

Most preferably, the state of the mechanism of the flat knitting machine further includes a combination of whether the stitch presser has advanced or retracted into the mouth and the area in which the carriage is located,
The controller is able to move the carriage in relation to the stitch presser status and carriage status.
If the stitch presser is located in an area where the stitch presser advances into the mouth and the carriage moves toward the end of the needle bed and the stitch presser interferes with the bracket at the end of the needle bed,
Or when the stitch presser advances into the mouth, the carriage is located in an area where it interferes with the bracket, and moves toward the end of the needle bed, it is determined that the carriage cannot be moved,
In other cases, it is determined that the carriage can be moved.
In this case, the stitch presser does not interfere with the bracket at the end of the needle bed.

Plan view of main part of flat knitting machine of embodiment Block diagram showing the control system of the flat knitting machine of the embodiment The flowchart which shows the control algorithm of the dynamic brake in an Example

  In the following, an optimum embodiment for carrying out the invention will be shown. The scope of the present invention should be construed in consideration of the possibility of modification by well-known techniques in the description of the scope of claims.

  1 to 3 show a flat knitting machine 2 according to an embodiment. Reference numeral 4 denotes a needle bed. The flat knitting machine 2 includes at least a pair of front and rear needle beds 4 and 4 and includes four needle beds in the front and rear and upper and lower directions. Also good. A plurality of needles are arranged on the needle bed 4, and the needles are operated by a carriage 6 that moves along the longitudinal direction of the needle bed 4. The carriage 6 is moved by a servo motor 10 via a belt 8 or the like. The servo motor 10 includes a speed reducer 12 and a dynamic brake 14, and the speed reducer 12 may be integrated with the servo motor 10 or separated.

  The carriage 6 includes knitting cams 16 at least on the front and rear sides, and in the embodiment, two knitting cams 16 are provided on the front and rear sides along the longitudinal direction of the needle bed 4. It should be noted that one to four knitting cams 16 may be provided on the front and rear along the longitudinal direction of the needle bed 4. The knitting cam 16 operates the needles of the needle bed 4 and moves them along a track such as knit, tack, or transfer. In the middle of knitting, if the carriage 6 stops while the needle is being operated, and then the carriage 6 moves in the direction opposite to the knitting direction, the knitting cam 16 may guide the needle to an unexpected state. .

  A needle selection actuator 18 is provided for each knitting cam 16 to select the needle on the needle bed 4 and the knitting cam 16 operates only the selected needle. In addition to this, a total of four stitch pressers 20 are provided on the carriage 6, for example, two in the front and rear, and the number thereof is equal to the number of knitting cams 16. The stitch presser 20 can be advanced and retracted into the mouth 5 between the needle beds 4 and 4, and when the stitch presser 20 has advanced into the mouth 5, the knitted fabric is pressed downward to facilitate knitting. The stitch presser 20 that has advanced into the mouth 5 has directionality, and movement in one direction along the needle bed 4 is not a problem, but movement in the opposite direction causes damage to the stitch presser 20 and damage to the knitted fabric. Cause. It should be noted that there is no problem even if the stitch presser retracted from the tooth opening 5 is moved to the left or right side with respect to the needle bed 4. For this reason, one of the stitch pressers 20 and 20 arranged in the reverse direction in the front and rear is advanced into the tooth mouth 5 so that the direction in which the stitch presser 20 can move and the knitting direction of the knitted fabric coincide.

  In addition to these, the flat knitting machine 2 includes a yarn feeder and a yarn feeder rail (not shown). When the carriage 6 is moved to the end of the needle bed 4, the stitch presser 20 that has advanced into the tooth mouth 5 may collide with a bracket or the like that supports the yarn feeder rail and be damaged.

  FIG. 2 shows a control system of the embodiment, and the main controller 24 that controls the entire flat knitting machine interprets the knitting data and controls the servo driver 28 and the carriage 6. Reference numeral 26 denotes a three-phase AC power source, which may be a two-phase AC or DC power source, and S1 is a position sensor that monitors the rotation speed of the servo motor 10 or monitors the position of the carriage 6 to The position is detected, and the velocity is detected from the change in position. A relay 30 opens and closes the contacts 31 to 33. When the contacts 31 to 33 are opened, the excitation of the servo motor 10 is turned off. A semiconductor switch or the like may be used in place of the relay 30. The servo drive 28 controls the current value to the servo motor 10 to move the carriage toward the target position commanded from the main controller 24. Further, the servo drive 28 performs feedback control of the servo motor 10 based on a signal from the position sensor S1 and a current value monitored by a current sensor (not shown).

  The dynamic brake 14 includes a dynamic brake controller 34 (hereinafter simply referred to as “controller 34”), and controls the contacts 37 and 38 via a relay 36. The state in which the contacts 37 and 38 are closed is a state in which the dynamic brake is on, and the state in which the contacts 37 and 38 are open is an off state. A semiconductor switch or the like may be used instead of the relay 36 or the like. The three-phase power lines of the servo motor 10 are short-circuited through the contacts 37 and 38 and the resistors R1 to R3. Here, the three power lines of u-phase, v-phase, and w-phase are all short-circuited to each other. Only two power sources of the phase and w phase may be short-circuited. The resistor R1 may not be provided. When the servomotor 10 with the excitation turned off is rotated by manually moving the carriage with the contacts 37 and 38 closed, an induced electromotive force is generated in the winding, and the three power lines are short-circuited. As a result, a large current flows. Therefore, a large braking force against the movement of the carriage can be obtained. When the contacts 37 and 38 are opened, the servo motor 10 has a braking force acting only to the extent of the sliding resistance that the carriage receives from the needle bed, and can easily move the carriage manually.

When the excitation of the servo motor 10 is off, the controller 34
The direction of movement of the carriage 6, in other words, the direction of rotation of the servo motor 10 is determined from the signal of the sensor S1,
-Confirm that the position of the carriage 6 is not within a predetermined area such as the end of the needle bed by a signal from the sensor S1 or a signal from the servo driver 28,
・ Obtain the state of the stitch presser from the signal of sensor S2 described later
-The dynamic brake 14 is turned on / off by a combination of these signals.

  In the carriage 6, the knitting cam is operated by the knitting cam actuator 40, the needles on the needle bed are selected by the needle selection actuator 18, and the stitch presser is operated by the presser actuator 42. The state of the stitch presser is detected by a sensor S2 including a proximity sensor.

  FIG. 3 shows a dynamic brake control algorithm. The dynamic brake control is started by turning off the excitation of the servo motor (step 1). The dynamic brake is initially turned off so that the carriage can be moved by a small predetermined distance of about 0.5 to 3 mm so that the dynamic brake is not turned on unnecessarily. In step 2, it is determined from the signal of the sensor S2 or the control data of the presser actuator whether the stitch presser is in the state of sinking (retracting) or any of the stitching pressers is in the state of exiting (advancing into the tooth mouth 5). If any stitch presser is out, it is confirmed in step 3 that the carriage movement direction is not the direction in which the stitch presser cannot move. In step 4, it is confirmed that there is no carriage in an unmovable area such as the end of the needle bed. In this confirmation, whether or not the carriage position is simply within the immovable area, or the carriage position is within the immovable area and the carriage moving direction approaches the inside of the immovable area. It may be confirmed whether or not. In FIG. 3, it is assumed that the carriage is not located in the non-movable area and that the carriage is non-movable.

  If all of the stitch pressers are dead, continue with step 2; if any of them appear, continue with step 4; determine whether or not the needle is being selected in step 5; (Step 7). If it is confirmed in Step 5 that the needle is being selected, it is confirmed in Step 6 that the carriage movement direction matches the knitting direction so far. If they match, the dynamic brake is turned off (Step 7). If so, the dynamic brake is turned on (step 8). The knitting direction is obtained from, for example, control data of the servo driver or knitting data. Steps 4 to 6 may be omitted.

  If any stitch presser advances into the mouth 5 between the needle beds and “exits” (step 2), the moving direction of the carriage matches the direction in which the stitch presser can move (step 3), and the carriage Is present outside the predetermined area (step 4) and the needle bed is not being selected (step 5), or the carriage movement direction matches the knitting direction (step 6). The brake is released (step 7). If all stitch pressers are retracted and are “dead” (step 2), the needle is not being selected (step 5), or the carriage movement direction matches the knitting direction (step 6). The brake is released (step 7). In cases other than these, the dynamic rake is turned on (step 8). Then, after executing Step 7, the process returns to Step 1. In addition, you may abbreviate | omit the process regarding the stitch presser in steps 2-4 with the flat knitting machine which is not equipped with a stitch presser. Further, in step 4, it is determined whether or not the carriage is located within a predetermined area in order to prevent interference between the bracket at the end of the needle bed and the stitch presser. It may be omitted for flat knitting machines that do not occur. Steps 5 and 6 are processes for preventing the needle from following an unexpected trajectory in the cam of the carriage, and may be omitted depending on the structure of the carriage.

In the embodiment, the following effects can be obtained.
1) When the carriage can be moved, the carriage can be moved manually, so that operations such as connecting the threads are facilitated.
2) If there is a problem with moving the carriage, the dynamic brake will be turned on, so there will be no damage to the flat knitting machine members or knitted fabric. That is, a member that can move only in one direction such as a stitch presser is not moved in the opposite direction. In addition, the stitch presser does not collide with a bracket or the like to be damaged. Furthermore, by moving the carriage in the direction opposite to the conventional knitting direction, the needle does not become an unexpected state.

2 Flat knitting machine 4 Needle bed 5 Tooth opening 6 Carriage 8 Belt 10 Servo motor 12 Reduction gear 14 Dynamic brake 16 Knitting cam 18 Needle selection actuator 20 Stitch presser 24 Main controller 26 Three-phase AC power supply 28 Servo driver 30, 36 Relay 31- 33 Contact 34 Dynamic brake controller 37, 38 Contact 40 Knitting cam actuator 42 Presser actuators R1-R3 Resistance S1 Position sensor S2 Sensor

Claims (4)

In a flat knitting machine in which a carriage for operating at least a pair of needle bed needles is moved by a servo motor along the longitudinal direction of the needle bed,
A dynamic brake configured by short-circuiting a plurality of windings included in the servo motor via a switch and a resistor;
A sensor for detecting the movement of the carriage;
When the excitation of the servo motor is turned off, the carriage movement is determined based on the carriage movement direction obtained from the sensor signal and the state of the other flat knitting machine mechanism. A flat knitting machine comprising: a controller for turning on or off the dynamic brake according to whether or not it is possible. The carriage advances and retracts into the mouth of the tooth bed between at least a pair of needle beds, and can move in one direction along the longitudinal direction of the needle bed when advanced into the tooth mouth. A stitch presser that cannot be moved in the opposite direction along the needle and that can move in any direction along the longitudinal direction of the needle bed in a state of being retracted from the mouth,
The state of the mechanism of the flat knitting machine includes at least the state of the stitch presser whether the stitch presser has advanced into or retracted from the mouth.
In relation to the state of the stitch presser, the controller determines whether the stitch presser has advanced into the mouth and the carriage movement direction obtained from the sensor signal is a direction in which the stitch presser can be moved. In any of the cases where the stitch presser is retracted from the mouth, it is determined that the carriage can be moved, and in other cases, it is determined that the carriage cannot be moved. The flat knitting machine according to claim 1. The state of the mechanism of the flat knitting machine further includes the state of the carriage whether or not the carriage is being selected,
The controller is
The carriage can be moved in relation to the state of the stitch presser,
In addition, the carriage is moved when the carriage is not selected, and when the carriage is selected and the carriage movement direction obtained from the sensor signal matches the knitting direction until the servo motor excitation is turned off. Judgment is possible,
3. The flat knitting machine according to claim 2, wherein in other cases, it is determined that the carriage cannot be moved. The state of the mechanism of the flat knitting machine further includes a combination of whether the stitch presser has advanced or retracted into the mouth and the area in which the carriage is located,
The controller can move the carriage in relation to the state of the stitch presser and the state of the carriage.
If the stitch presser is located in an area where the stitch presser advances into the mouth and the carriage moves toward the end of the needle bed and the stitch presser interferes with the bracket at the end of the needle bed,
Or when the stitch presser advances into the mouth, the carriage is located in an area where it interferes with the bracket, and moves toward the end of the needle bed, it is determined that the carriage cannot be moved,
4. The flat knitting machine according to claim 3, wherein in other cases, it is determined that the carriage can be moved.

Images