JP5253993B2 - sewing machine - Google Patents

Description

  The present invention relates to a sewing machine having an intermediate presser.

In conventional sewing machines, the sewing product is pressed by an intermediate presser that moves up and down with a smaller stroke than the sewing needle so that the sewing product is not pulled by the sewing needle that moves up. Since the up-and-down movement is performed in the vicinity, there is a problem that in the case of a thick workpiece, the workpiece is stepped on and damaged when the intermediate presser is lowered.
Therefore, a conventional sewing machine is provided with a stepping motor that adjusts the vertical position of the intermediate presser by moving the intermediate presser up and down separately from the sewing machine motor, and a cloth thickness detector composed of an optical element. Based on this, control is performed to adjust the bottom dead center height of the intermediate presser by the stepping motor (see, for example, Patent Document 1).
Japanese Examined Patent Publication No. 7-44983 (Fig. 5)

However, in the conventional sewing machine in Patent Document 1, the cloth thickness detector made of an optical element detects the thickness of the natural state including the wiping of the sewing object, and is compressed with the sewing thread. Since the cloth thickness cannot be detected, the value of the detected thickness will increase, and as a result, the adjusted setting position of the intermediate presser will be too high, and the sewing product will not rise properly when the sewing needle is raised. There is a problem that it cannot be pressed. In addition, a dedicated cloth thickness detector is indispensable, and there is a problem in that productivity decreases due to an increase in the number of parts. The cloth thickness detector must be placed around the needle bar where the item to be sewn is located, but the intermediate presser and its vertical movement mechanism are provided, and the space for placing the cloth thickness detector around the needle bar is provided. There was also a problem that it was difficult to ensure.
An object of the present invention is to accurately detect the thickness of a sewing product compressed by a seam while driving a sewing machine while reducing the number of parts and ensuring a wide space around a needle bar. .

  According to a first aspect of the present invention, there is provided a needle up-and-down movement mechanism that moves a sewing needle up and down by a sewing motor, a positioning mechanism that relatively positions the sewing needle and a workpiece by a positioning motor, and the sewing needle for each needle. Storage means for storing sewing pattern data including position information for determining the relative position of the workpiece, spindle angle detection means for detecting the angle of the spindle driven to rotate by the sewing machine motor, and lifting of the workpiece during sewing An intermediate presser and a middle presser vertical movement mechanism that obtains power from the sewing machine motor and moves the intermediate presser up and down in synchronization with the vertical movement of the sewing needle, and the intermediate presser vertical movement mechanism by an intermediate presser motor. An intermediate presser that moves the intermediate presser up and down separately from the sewing machine motor by changing the posture of the motion transmitting member and supporting the post-change posture. And a sewing control means for driving the positioning mechanism for each stitch according to the sewing pattern data while synchronizing with the raising and lowering of the intermediate presser performed by the intermediate presser vertical mechanism by driving the sewing machine motor. In the sewing machine, motor shaft angle detecting means for detecting the angle of the output shaft of the intermediate presser motor, and the vertical press by the intermediate presser height adjusting mechanism between the start of lowering or the middle of the intermediate presser to the bottom dead center. When the posture of the motion transmission member is maintained so as not to cause a change in position and when an external torque is applied to the output shaft of the intermediate presser motor due to the contact of the intermediate presser with the sewing product, the intermediate presser is moved upward. Intermediate presser height control means for performing variable height control for controlling the output of the intermediate presser motor so as to cause rotation in the moving direction; A thickness acquisition processing means for performing a thickness acquisition process for obtaining a thickness of the sewing product from a detection angle of an output shaft angle of the intermediate press motor at a dead center, and the intermediate presser height control means includes the height Before the variable control, the sewing machine controls the intermediate presser motor so that the intermediate presser height when the intermediate presser is at bottom dead center is lower than the upper surface of the needle plate.

  The invention described in claim 2 has the same configuration as that of the invention described in claim 1, and is based on sewing pattern data including position information for determining the relative position of the sewing product with respect to the sewing needle for each stitch. Sewing control means for controlling the operation of the positioning motor, and thickness recording means for recording the acquired thickness of the sewing object in association with the sewing pattern data in the order of the number of stitches. It is characterized by.

  The invention described in claim 3 has the same configuration as that of the invention described in claim 1 or 2, and supports other motion transmitting members of the intermediate presser vertical movement mechanism by elastic force and inhibits the lowering of the intermediate presser. A pressing spring for avoiding an excessive load with respect to the intermediate presser vertical movement mechanism that allows the other operation transmitting member to escape when a load greater than the elastic force is generated on the other operation transmitting member. It is characterized by providing.

  According to the first aspect of the present invention, since the intermediate presser height control means rotates the output shaft in a direction in which the intermediate presser motor moves the intermediate presser upward when the intermediate presser comes into contact with the workpiece by lowering the intermediate presser. The pressing of objects is avoided.

Furthermore, the invention described in claim 1 is when the positioning mechanism is operated according to the sewing pattern data while driving the sewing machine motor to move the sewing needle and the intermediate presser up and down, and the intermediate presser height control means includes: Before the variable height control, the intermediate presser motor is set so that the intermediate presser height is below the top of the needle plate when the intermediate presser is at the bottom dead center (the bottom dead center in the vertical movement by the intermediate presser vertical movement mechanism). Is controlling.
For example, in the vertical movement of the intermediate presser, if the height at the bottom dead center of the intermediate presser is set to coincide with the upper surface of the needle plate, if the sewing product is a thin material, Before the intermediate presser comes into contact and the output shaft of the intermediate presser motor starts rotating, the intermediate presser moves up and down by the intermediate presser vertical movement mechanism, and the angle change of the output shaft of the intermediate presser motor can be obtained well. As a result, there arises a problem that the thickness of the sewing product cannot be satisfactorily detected.
However, in the first aspect of the invention, since the target lowering height of the intermediate presser is set lower than the needle plate (the bottom portion of the intermediate presser is lower than the upper surface of the needle plate), the lower intermediate presser is the sewing product. Even after coming into contact, the lowering operation continues to be applied by the intermediate presser motor vertical movement mechanism, and as a result, the output shaft of the intermediate presser motor sufficiently rotates. In other words, it is possible to avoid a situation in which the intermediate presser is turned back before the output shaft of the intermediate presser motor is rotated, and as a result, even if the material to be sewn is a thin material, the thickness of the presser is excellent. Detection can be performed.

Further, according to the above invention, the thickness of the sewing product can be obtained without using a cloth thickness detector that performs contact position detection, distance detection, etc., and it is possible to improve productivity by reducing the number of parts. Become. Also, without using the cloth thickness detector that detects the contact position or distance, the cloth thickness is detected by bringing the intermediate press into contact with the workpiece. The cloth thickness in a state compressed with the sewing thread can be detected, and the sewing quality can be improved.
Furthermore, since the press at the time of contact with the sewing product by the intermediate presser is suppressed by the intermediate presser motor, it is possible to avoid damaging the sewing product by pressing, and the sewing quality can be improved by protecting the sewing product. It becomes possible.

In addition, the execution section of the height variable control is not limited to the start of the lowering operation of the intermediate presser, and may be started after the height is lowered to a height that can contact the sewing product. In other words, when the height is inaccessible to the sewing product (for example, the height cannot be in contact with the thickness of the sewing product to be sewn), the intermediate presser motor is placed under the intermediate presser against the presser spring. The control may be performed so that a normal torque capable of maintaining the dead point is obtained, and the height variable control may be started after the height is lowered to a height at which the dead center can be contacted.
Further, the torque of the intermediate presser motor in the variable height control is required to be reduced to such an extent that the intermediate presser height adjusting mechanism does not move upward when it is lowered.

  In the invention according to claim 2, the height variable control is executed in synchronization with the relative positioning operation of the sewing object for each needle executed according to the sewing pattern data, and the thickness acquisition process of each needle is executed, Since the thickness of the sewing product is recorded in the sewing pattern data in correspondence with the number of stitches, the bottom dead center height of the appropriate intermediate presser is adjusted while adjusting the height of the intermediate presser with respect to the sewing product. Compared to the case where sewing pattern data setting work is performed by setting the sewing machine, it is possible to easily obtain sewing pattern data that takes into account the thickness of the workpiece to be sewn, eliminating the need for complicated setting work and reducing the work load. It becomes possible.

According to a third aspect of the present invention, a pressing spring for avoiding excessive load is provided, and when the descending intermediate presser comes into contact with the sewing object, the pressing spring expands or contracts to allow the other motion transmitting members to escape. This makes it possible to prevent breakage of each member of the intermediate presser vertical movement mechanism.
With this presser spring, when the lower intermediate presser comes into contact with the workpiece, it is possible to urge the intermediate presser motor to rotate with respect to the output shaft by its elastic force.
When such a presser spring is present, particularly when the height at the bottom dead center of the intermediate presser is set to coincide with the upper surface of the needle plate and the sewing product is a thin material, The application of the rotational force to the output shaft of the intermediate pressing motor due to the contact is absorbed by the expansion and contraction of the pressing spring, and in particular, there is a tendency to hinder the good detection of the thickness. As described above, the output shaft of the intermediate presser motor can be effectively rotated, and the thickness can be detected satisfactorily even when the material to be sewn is a thin material.

Hereinafter, embodiments of a sewing machine according to the present invention will be described in detail with reference to the drawings.
In the present embodiment, an electronic cycle sewing machine will be described as an example of the sewing machine.
The electronic cycle sewing machine has a holding frame that holds a cloth that is a sewing object to be sewn, and the holding frame moves relative to the sewing needle, so that a predetermined sewing is performed on the cloth held by the holding frame. The sewing machine forms a seam based on pattern data (sewing pattern).
Here, the direction in which the sewing needle 108 described later moves up and down is the Z-axis direction (up-and-down direction), and one direction orthogonal to this is the X-axis direction (left-and-right direction). The direction perpendicular to the Y axis direction is defined as the Y-axis direction (front-rear direction).

  As shown in FIG. 1, an electronic cycle sewing machine 100 (hereinafter referred to as a sewing machine 100) is provided with a sewing machine main body 101 provided on the upper surface of the sewing machine table T and a lower part of the sewing machine table T, and operates the start and stop of sewing. A pedal R for operation, an operation panel 74 provided on an upper part of the sewing machine table T for performing an input operation by a user, and the like.

(Sewing frame and spindle)
As shown in FIGS. 1 and 2, the sewing machine main body 101 includes a sewing machine frame 102 whose outer shape is substantially U-shaped in a side view. The sewing machine frame 102 has an upper part of the sewing machine body 101 and extends in the front-rear direction, a sewing machine bed part 102 b that forms the lower part of the sewing machine body 101 and extends in the front-rear direction, and the sewing machine arm part 102 a and the sewing machine bed part 102 b. And a vertical body portion 102c that connects the two.
The sewing machine main body 101 includes a main shaft 2 (see FIG. 4) and a lower shaft (not shown). The main shaft 2 is disposed inside the sewing machine arm portion 102a, and the lower shaft (not shown) is disposed inside the sewing machine bed portion 102b.

The main shaft 2 is connected to a sewing machine motor 2a (see FIG. 8), and rotational power is applied by the sewing machine motor 2a. The lower shaft (not shown) is connected to the main shaft 2 via a vertical axis (not shown). When the main shaft 2 rotates, the power of the main shaft 2 is transmitted to the lower shaft side via the vertical axis. The lower shaft rotates.
A needle bar 108a that moves up and down in the Z-axis direction by the rotation of the main shaft 2 is connected to the front end of the main shaft 2, and a sewing needle 108 is replaceably provided at the lower end of the needle bar 108a. That is, the sewing needle 108 moves up and down in the Z-axis direction as the main shaft 2 rotates.
The needle vertical movement mechanism is constituted by the main shaft 2, the sewing machine motor 2a, the needle bar 108a, and a transmission mechanism (not shown) that applies a driving force for vertical movement from the main shaft 2 to the needle bar 108a.

  The main shaft 2 is provided with an encoder 2b (see FIG. 7) as main shaft angle detecting means. The encoder 2b detects the rotation angle of the main shaft 2 of the sewing machine motor 2a. For example, the encoder 2b outputs a pulse signal to the control device 1000 every time the main shaft 2 rotates 1 ° by the sewing machine motor 2a. Further, as the main shaft 2 rotates once, the needle bar 108a performs one reciprocating motion.

A hook (not shown) is provided at the front end of the lower shaft (not shown). When the lower shaft rotates together with the main shaft 2, a seam is formed by the cooperation of the sewing needle 108 and the shuttle (not shown).
The connection configuration of the sewing machine motor 2a, the main shaft 2, the needle bar 108a, the sewing needle 108, the lower shaft (not shown), the shuttle (not shown) and the like are the same as those conventionally known and will not be described in detail here.

(Positioning means)
As shown in FIGS. 1 and 2, a needle plate 110 is disposed on the sewing machine bed portion 102 b, and a holding frame 111 and a sewing needle 108 as a cloth holding portion are disposed above the needle plate 110. It has become so.
The holding frame 111 is attached to an attachment member 113 disposed at the front end of the sewing machine arm portion 102a. The attachment member 113 has an X-axis motor 76a and a Y-axis as positioning motors arranged in the sewing machine bed 102b. A motor 77a is connected as drive means (see FIG. 7).
The holding frame 111 holds the cloth that is the sewing object, and moves the held cloth in the front-rear and left-right directions together with the holding frame 111 as the X-axis motor 76a and the Y-axis motor 77a are driven. Then, the movement of the holding frame 111 and the operation of the sewing needle 108 and the hook (not shown) are interlocked to form a seam based on the seam data of predetermined sewing pattern data on the fabric.
The holding frame 111 includes a cloth presser (not shown) and a lower plate (not shown), and the mounting member 113 can be driven up and down by driving a cloth presser motor 79b disposed in the sewing machine arm 102a. Yes, the fabric is clamped and held between the lower plate when the fabric presser is lowered.
The holding frame 111, the mounting member 113, the X-axis motor 76a, and the Y-axis motor 77a function as a positioning mechanism that relatively positions the sewing needle and the fabric in the X-axis direction and the Y-axis direction.

  The pedal R operates as an operation pedal for driving the sewing machine 100 and moving the needle bar 108a (the sewing needle 108) up and down and operating the holding frame 111. That is, the pedal R incorporates a sensor for detecting the depression operation position when the pedal R is depressed, and an output signal from the sensor is output as an operation signal of the pedal R to the control device 1000 described later, and the control is performed. The apparatus 1000 is configured to drive and operate the sewing machine 100 according to the operation position and operation signal.

In addition, the sewing machine 100 is provided with an operation panel 74 for performing an operation input by a user, and various data and operation signals input to the operation panel 74 are output to a control device 1000 described later.
The operation panel 74 includes a liquid crystal display panel and a touch panel provided on the display screen of the liquid crystal display panel, and is operated by touching various operation keys displayed on the liquid crystal display panel. The position where the touch panel is touched is detected, and an operation signal corresponding to the detected position is output to the control device 1000 described later.

(Medium holding device)
In order to prevent the cloth from being lifted by the vertical movement of the sewing needle 108, the sewing machine arm 102a moves up and down in conjunction with the vertical movement of the needle bar 108a and presses the cloth around the sewing needle 108 downward. An intermediate pressing device 1 having 29 (see FIG. 3) is provided. Note that the main body of the intermediate presser 1 is disposed inside the sewing machine arm portion 102 a, and the sewing needle 108 is inserted into a through hole formed on the distal end side of the intermediate presser 29.
As shown in FIGS. 3 to 5, the intermediate presser 1 includes an intermediate presser 29 that presses the cloth against the needle plate 110 during sewing and a sewing presser 108 that moves up and down by the rotation of the main shaft 2. An intermediate presser vertical movement mechanism M1 that moves up and down, an urging mechanism M2 that enables the escape operation that is performed when the lowering operation of the intermediate presser 29 is inhibited and that urges the intermediate presser 29 toward the needle plate 110 during the escape operation The intermediate presser retracting mechanism M3 that raises the intermediate presser 29 to the retracted height position after the end of sewing and the intermediate presser height adjusting mechanism M4 that adjusts the height of the intermediate presser 29 are provided.

The intermediate presser vertical movement mechanism M1 moves the intermediate presser 29 up and down by the rotation of the main shaft 2 (see FIG. 4) that drives the needle bar 108 having the sewing needle 108 at the tip in the vertical direction.
As shown in FIG. 4, an eccentric cam 3 is fixed to the main shaft 2, and a connection link 4 is connected to the eccentric cam 3. A rocking shaft holder 5 is connected to the connection link 4, and one end of the rocking shaft 6 is connected to the rocking shaft holder 5.
As shown in FIG. 5, the base end portion of the intermediate presser adjustment arm 7 that adjusts the amount of movement of the intermediate presser in the vertical direction D <b> 1 is fixed to the other end portion of the swing shaft 6. A groove cam 7 a is formed on the intermediate presser adjusting arm 7. The groove cam 7a is an arc-shaped long hole, and one end of the first link 8 is pivotally supported by an adjusting nut 9 and a step screw 10 at a desired position of the groove cam 7a. The fixed position of the one end portion of the first link 8 can be adjusted toward and away from the center of the swing shaft 6, and the amount of reciprocating motion applied to the first link 8 is increased or decreased in proportion to the distance from the center. be able to.

As shown in FIG. 5, the other end of the first link 8 is connected to the middle of the second link 11 in the longitudinal direction by a step screw 12 so as to be rotatable. Here, the groove cam 7a with which the adjusting nut 9 is engaged is formed so as to be a part of an arc centered on the axis of the step screw 12 when the intermediate presser 29 is at the bottom dead center of the vertical reciprocation. Has been. In other words, by adjusting the position of the first link 8 in the cam groove 7a when the angle of the upper shaft 2 is in a phase for moving the intermediate presser 29 to the bottom dead center, the bottom dead center position of the intermediate presser 29 is fixed. Stroke adjustment can be performed as it is.
However, as will be described later, the sewing machine 10 performs a process of calculating the thickness of the sewing product. However, in this case, since the vertical movement stroke of the intermediate presser vertical movement mechanism M1 is involved, the adjustment is not performed freely. . Further, when adjusting, it is necessary to set and input the stroke value as a parameter for calculating the thickness of the sewing product into the control device 1000 and update it.

  And the one end part of the 2nd link 11 is pivotally supported by the positioning link 13 mentioned later. When one end of the second link 11 is pivotally supported by the positioning link 13 and the intermediate presser 29 moves up and down during normal sewing, the one end of the second link 11 is caused by the elastic force of the tension spring 16. Is kept pressed against the regulating member 19. When the intermediate presser 29 cannot be lowered to the planned bottom dead center position by stepping on the fabric or being caught by something, the positioning link 13 rotates against the elastic force of the tension spring 16, and The fulcrum at one end of the two links 11 descends against the tension spring 16 so that the intermediate presser 29 can escape upward. As a result, the intermediate presser vertical movement mechanism M1 is prevented from being damaged.

As shown in FIG. 5, the other end of the second link 11 is rotatably connected to one end of the third link 20 by a step screw 21. One end of the fourth link 22 is rotatably connected to the other end of the third link 20 by a step screw 23 so as to be in series with the longitudinal direction of the third link 20. In the present embodiment, the third link 20 and the fourth link 22 constitute an intermediate presser link member 24.
A link relay plate 25 is connected to the other end of the fourth link 22 by a step screw 26. An intermediate presser bar holder 27 is fixed to the link relay plate 25, and an intermediate presser bar 28 extending in the vertical direction is held on the intermediate presser bar holder 27. An intermediate presser 29 is attached to the lower end of the intermediate presser bar 28 to press the fabric against the needle plate 110 during sewing. A pressing spring 30 is provided at the upper end portion of the intermediate presser bar 28 and is attached to the intermediate presser bar holder 27 by a bolt 31 and a nut 32. The pressing spring 30 always presses the intermediate presser 29 downward when the intermediate presser 29 moves up and down in synchronization with the sewing needle 108 during sewing.
In the present embodiment, the first link 8, the second link 11, the third link 20, the fourth link 22, and the like constitute an intermediate presser vertical movement mechanism M1.

  The step screw 23 connects the third link 20 and the fourth link 22 together with the square piece 33 and the guide member 34. That is, a guide member 34 is provided on the front side of the fourth link 22, and a square piece 33 is provided on the front side of the guide member 34, and the third link 20, the fourth link 22, the square piece 33, and A guide member 34 is connected by one step screw 23.

  The guide member 34 is a substantially F-shaped plate member, and an upper end portion 34t is rotatably attached to the sewing machine casing (sewing machine frame 102) by a step screw 35. In the vicinity of the lower end portion of the guide member 34, a long hole 34a elongated in the vertical direction is formed. The long hole 34 a is fitted with a square piece 33 slidably inside, and the guide member 34 can move the connecting portion P of the third link 20 and the fourth link 22 in the vertical direction D 1 of the intermediate presser 29. And the movement of the third link 20 and the fourth link 22 in the direction D3 across the series direction D2 is restricted.

Further, as shown in FIG. 5, the guide member 34 has an end portion of a moving link 36 that moves the guide member 34 in a direction D <b> 3 across the series direction D <b> 2 of the third link 20 and the fourth link 22. 37 is rotatably connected to the vicinity of the upper portion of the long hole 34a. An eccentric cam 38 is connected to the other end of the moving link 36, and one end of a variable shaft 39 is connected to the eccentric cam 38.
As shown in FIG. 4, the other end of the variable shaft 39 is connected to an intermediate presser motor 42 via a bearing 40 and a bevel gear 41. That is, the driving of the intermediate presser motor 42 is transmitted in the order of the variable shaft 39, the eccentric cam 38, and the moving link 36, and the moving link 36 moves the guide member 34.
The intermediate presser motor 42 is rotatable in forward and reverse directions, and the amount of rotation and the drive timing can be controlled by the control device 1000.
The moving link 36, the guide member 34, the square piece 33, and the like function as an intermediate presser height adjustment mechanism M4 that adjusts the height of the intermediate presser 29.

The positioning link 13 is rotatably attached to a sewing machine frame 102 as a sewing machine case by a step screw 14 in the vicinity of the center thereof, and the position of the step screw 14 is the step screw when the intermediate presser 29 is at the bottom dead center. 12 positions are coincident with each other.
One end of the positioning link 13 is folded back in a substantially U shape toward the sewing machine surface, and a spring hook 13a is formed at the folded tip. The positioning link 13 in this embodiment has a spring hook 13a at one end thereof folded back to the vicinity of the step screw 14 that is the rotation center of the positioning link 13, and the distance from the rotation center to the spring hook 13a is shortened. It is formed as follows. One end (upper end) of the tension spring 16 is connected to the spring hook 13a, and the other end (lower end) of the tension spring 16 is connected to a spring hook 15 fixed to the sewing machine frame.
The tension spring 16 urges the one end of the positioning link 13 on which the spring hook 13a is formed to be lowered. That is, the tension spring 16 is connected when the connection portion of the second link 11 with the third link 20 receives a reaction force and receives an upward reaction force due to the occurrence of stepping by the intermediate presser 29. Energize to pull the part down. In other words, the tension spring 16 and the positioning link 13 allow the intermediate presser vertical movement mechanism M1 to perform an escape operation for avoiding an excessive load when the lowering operation of the intermediate presser 29 is inhibited, and the intermediate presser 29 is moved to the needle plate during the escape operation. It functions as an urging mechanism M2 that urges to the 110 side. The tension spring 16 functions as a pressing spring for avoiding excessive load. In addition, the second link 11 functions as “another motion transmission member” that performs an escape operation.
The urging mechanism M2 is connected to the intermediate presser vertical movement mechanism M1 by connecting the positioning link 13 to the second link 11.

  A stopper 17 is connected to the other end of the positioning link 13, and one end of the second link 11 and the other end of the positioning link 13 are connected by a single stepped screw 18. The stopper 17 is rotatably attached to the sewing machine frame 102 together with the positioning link 13 by a step screw 14. A restricting member 19 is provided above the one end portion 17 a of the stopper 17 so as to restrict the upward movement of the one end portion of the stopper 17. The restricting member 19 may be replaced with a part of the sewing machine frame 102.

  As shown in FIG. 4, a bevel gear 43 is engaged with the bevel gear 41, and the drive of the intermediate pressing motor 42 can be output in a direction D <b> 4 orthogonal to the axial direction of the variable shaft 39. ing. A bearing 44, an intermediate presser raising / lowering cam 45, and the like are coaxially connected to the rear end of the bevel gear 43.

The intermediate presser raising / lowering cam 45 is a groove cam having a groove (not shown) on its axial end face.
The groove of the intermediate presser raising / lowering cam 45 is a cam portion, and half of the rotation range of the intermediate presser raising / lowering cam 45 is formed in an arc shape whose distance from the center of rotation to the groove is substantially the same (hereinafter referred to as an arc). The remaining half is a shape in which the distance from the rotation center to the groove is larger than the distance from the rotation center to the groove in the maintenance part and changes smoothly (hereinafter referred to as a change part). It has become.
This intermediate presser raising / lowering cam 45 moves up and down one end portion 46a of the intermediate presser raising member 46 that raises the intermediate presser 29 to the retracted position after the sewing is completed. A cylindrical roller 47 provided at the other end of the intermediate presser lifting member 46 is slidably fitted. When the roller 47 moves along the maintaining portion of the intermediate presser raising / lowering cam 45, the one end portion 46a of the intermediate presser lifting / lowering member 46 does not move up / down, but the roller 47 moves along the changing portion of the intermediate presser lifting / lowering cam 45. When moving, the one end 46a of the intermediate presser lifting member 46 moves up and down.
Since the other end portion of the presser lifting member 46 is engaged with the inner side of the groove (not shown) of the intermediate presser raising / lowering cam 45 which is such a groove cam via the roller 47, the intermediate presser raising / lowering cam 45 rotates. As long as there is no limit, the intermediate presser lifting member 46 does not swing and can maintain a constant state. The intermediate presser raising / lowering cam 45, the intermediate presser lifting member 46, and the roller 47 constitute an intermediate presser retracting mechanism M3.

  The intermediate presser lifting member 46 is rotatably attached to and supported by the sewing machine frame 102 by a shaft member, that is, a pin 48 at its middle abdomen. The intermediate presser lifting member 46 is provided so that one end portion 46a thereof is positioned below the intermediate presser bar holder 27, and the roller 47 moves along the changing portion of the intermediate presser raising / lowering cam 45 so that the intermediate presser lifter 46 is moved. When the one end 46a of the member 46 is raised, the intermediate presser bar holder 27 can be raised, and the intermediate presser 29 can be raised to the retracted position.

(Operation of the intermediate presser during sewing)
Next, the operation of the intermediate presser vertical movement mechanism M1 having the above configuration will be described.
When the main shaft 2 is rotated by driving the sewing machine motor 2a to rotate the eccentric cam 3, the tip of the connection link 4 is in a direction substantially perpendicular to the axis of the main shaft 2 (the series direction D2 of the third link 20 and the fourth link 22). Oscillating in the direction D3) transverse to the oscillating shaft, and the oscillating shaft holder 5 connected to the connecting link 4 also oscillates in the same direction. Since the swing shaft holder 5 swings, the swing shaft 6 also swings. Therefore, one end of the first link 8 serves as a swing fulcrum, and the other end of the first link 8 serves as the swing shaft 6. Oscillates in a direction substantially perpendicular to the axis (direction D3 transverse to the series direction D2 of the third link 20 and the fourth link 22). As the other end portion of the first link 8 swings, the other end portion of the second link 11 swings in the series direction D2 of the third link 20 and the fourth link 22, and the other end portion of the second link 11 The connected third link 20 and fourth link 22 swing in the series direction (vertical direction) D2. As the third link 20 and the fourth link 22 swing, the intermediate presser bar 28 connected to the fourth link 22 moves downward along the vertical direction D1, so the intermediate presser 29 moves in the vertical direction. Further, since the sewing needle 108 moves up and down by the rotation of the main shaft 2, the intermediate presser 29 moves up and down so as to interlock with the vertical movement of the sewing needle 108.
In the following description, the sewing needle 108 and the intermediate presser 29 are positioned at the top dead center when the angle of the main shaft 2 is 0 °, and the sewing needle 108 and the intermediate presser 29 are lowered when the angle of the main shaft 2 is 180 °. It shall be located at the dead point.

(Adjustment operation of intermediate presser height by intermediate presser)
Next, the operation of adjusting the height of the intermediate presser 29 by the intermediate presser height adjusting mechanism M4 of the intermediate presser device 1 having the above configuration will be described.
The drive of the intermediate presser motor 42 is transmitted to the movable shaft 39 via the bevel gear 41 and the bearing 40, and the movable shaft 39 starts to rotate. The eccentric cam 38 is also rotated by the rotation of the movable shaft 39, and the moving link 36 is in a direction substantially orthogonal to the axis of the movable shaft 39 (a direction crossing the series direction D2 of the third link 20 and the fourth link 22). Swing to D3). As the moving link 36 swings, the guide member 34 swings in a direction D3 that intersects the series direction D2 of the third link 20 and the fourth link 22.
At this time, as shown in FIGS. 6A and 6B, the stepped screw 23 (square piece 33) of the connecting portion P of the third link 20 and the fourth link 22 connected by the elongated hole 34a of the guide member 34. Since the screw portion is restricted by the long hole 34a from moving in the direction D3 across the series direction D2 of the third link 20 and the fourth link 22 (see FIG. 6A), the rocking portion The step screw 23 (square piece 33) moves upward along the long hole 34a and the movement following the guide member 34 of the step screw 23 (square piece 33) disappears. The angle formed between the third link 20 and the fourth link 22 that are connected in series is changed, and the intermediate presser link member 24 has a substantially square shape (see FIG. 6B). When the intermediate presser link member 24 has a substantially square shape, the intermediate presser 29 moves upward along the vertical direction D1. Thereby, the height of the intermediate presser 29 from the needle plate 110 of the intermediate presser 29 can be adjusted.

(Sewing machine control system: control device)
Further, as shown in FIG. 7, the sewing machine 100 includes a control device 1000 as an operation control unit for controlling the operation of each unit and each member described above. The control device 1000 stores a program memory 70 in which a sewing program 70a, a frame position teaching program 70b, and an intermediate presser height teaching program 70c are stored, a sewing pattern data 71a, and various setting information (not shown). A data memory 71 as means and a CPU 73 for executing each program 70a, 70b, 70c in the program memory 70 are provided.

  The CPU 73 is connected to the operation panel 74 via the interface 74a. The operation panel 74 includes a display unit 74b that displays various screens and input buttons, and a touch sensor 74c that is provided on the surface of the display unit 74b and detects a contact position thereof, and functions as an input / output unit for various types of information. To do. Any of the input buttons and input switches used on the operation panel 74 are displayed on the display unit 74b and function in the same manner as push-down buttons and switches when an input is detected by the touch sensor 74c.

The CPU 73 is connected to a sewing machine motor driving circuit 75b that drives the sewing machine motor 2a via the interface 75, and controls the rotation of the sewing machine motor 2a. Further, the increase / decrease in torque can be adjusted by controlling the energization current of the sewing machine motor 2a through the sewing machine motor drive circuit 75b.
The sewing machine motor 2a is provided with an encoder 2b. In the sewing machine motor driving circuit 75b for driving the sewing machine motor 2a, a Z-phase signal output from the encoder 2b for each rotation of the sewing machine motor 2a is transmitted via the interface 75. Input to the CPU 73, and the CPU 73 can recognize the origin (0 ° position) in one rotation of the main shaft 2 by this signal. Further, an A-phase signal output from the encoder 2b every 1 ° in the rotation angle of the sewing machine motor 2a is input to the CPU 73 via the interface 75, and the number of pulses of the A-phase signal based on the Z-phase signal described above. The CPU 73 can recognize the current rotation angle of the main shaft 2.
For example, a servo motor can be applied to the sewing machine motor 2a.

  The CPU 73 also has an X-axis motor driving circuit 76b and a Y-axis motor for driving an X-axis motor 76a and a Y-axis motor 77a provided in the holding frame 111 that holds the fabric to be sewn via the interface 76 and the interface 77, respectively. A drive circuit 77b is connected to control the operation of the holding frame 111 in the X-axis direction and the Y-axis direction.

The CPU 73 is connected to an intermediate presser motor drive circuit 78b for driving an intermediate presser motor 42 that can move the intermediate presser 29 up and down separately from the vertical movement by the sewing machine motor 2a via the interface 78. Control the behavior. Further, the increase / decrease in torque can be adjusted by controlling the energization current of the intermediate presser motor 42 through the intermediate presser motor drive circuit 78b.
The output shaft of the intermediate presser motor 42 is provided with an encoder 81 as a motor shaft angle detecting means. In the intermediate presser motor drive circuit 79b for driving the intermediate presser motor 42, the encoder 81 is connected to one of the intermediate presser motors 42. A Z-phase signal output for each rotation is input to the CPU 73 via the interface 75, and the CPU 73 can recognize the origin (0 ° position) in one rotation of the output shaft of the intermediate presser motor 42 by this signal. Further, an A-phase signal output from the encoder 81 every 1 ° in the rotation angle of the intermediate presser motor 42 is input to the CPU 73 via the interface 78, and the pulse of the A-phase signal is based on the Z-phase signal described above. Counting the number, the CPU 73 can recognize the current rotation angle of the output shaft of the intermediate press motor.

Further, the CPU 73 is connected to a cloth presser motor driving circuit 79b for driving a cloth presser motor 79a that moves the cloth presser (not shown) up and down via the interface 79, and controls the vertical movement operation of the cloth presser.
The cloth presser motor 79a is connected to a cloth presser vertical movement mechanism and a thread trimming device (not shown) via a cam mechanism, and the cloth presser moves up and down in a part of a 360 ° rotation range. The other section is assigned to drive the thread trimming operation of the thread trimming device. Therefore, by controlling the cloth presser motor 79a, not only the vertical movement operation of the cloth presser but also the thread trimming operation can be controlled.
For example, a stepping motor can be applied to the X-axis motor 76a, the Y-axis motor 77a, the intermediate presser motor 42, and the cloth presser motor 79a.

  Further, the CPU 73 is connected to a solenoid drive circuit 82b that drives a thread tension solenoid 82a that is a drive source of a thread tension device (not shown) that applies a thread tension to the sewing thread via the interface 82, and increases or decreases the thread tension. Control.

As shown in FIG. 8, the sewing pattern data 71a stored in the data memory 71 includes an X-direction movement amount and a Y-direction movement when the holding frame 111 is moved in order to execute a hand movement pattern for sewing. A sewing command indicating the amount data (stitch data indicating the needle entry position), an end command, an intermediate presser height command that determines the bottom dead center height of the intermediate presser 29, a thread tension command, a thread trimming command, and an end command are combined. ing.
Then, various commands are executed in accordance with the arrangement order, whereby sewing with an arbitrary pattern (pattern) is executed.
In the sewing pattern data shown in FIG. 8, in the “sewing” command, the X-direction movement amount and Y-direction movement amount data (parameters) when moving the holding frame 111 are set to the first set value and the second set value. These are recorded, and the rotational drive amounts of the X-axis motor 76a and the Y-axis motor 77a are determined by these.
The “intermediate presser height” command controls the output shaft angle of the intermediate presser motor 42 so that the intermediate presser 29 has a bottom dead center height corresponding to the cloth thickness at each needle drop position of the sewing product. The bottom dead center height of the intermediate presser 29 determined by the intermediate presser motor 42 is recorded in the first set value, and the rotational drive amount of the intermediate presser motor 42 is determined thereby.
In the “thread tension” command, the thread tension to be applied to the sewing thread by the thread tension device is recorded as the first set value, and the output of the thread tension solenoid 82a is determined thereby.
“Thread trimming” is a command for operating a thread trimming device (not shown), and “End” is a command for driving the cloth pressing motor 79a of the sewing machine 100 to release the cloth.
In addition, the notation in the numerical data of the X movement amount, the Y movement amount, and the intermediate presser height in FIG. 8 is 10 times, for example, “15” indicates “1.5 mm”.
Further, although not shown, the sewing pattern data 71a can also record the hardness of the sewing product acquired by executing an intermediate presser height teaching program 70c described later.

(Sewing process by sewing program)
The sewing program 70a stored in the program memory 70 reads out each command of the sewing pattern data 71a in order, specifies the control target according to the command, and based on the set numerical value in the command, the sewing machine motor 2a, the X axis This program controls the operation of the motor 76a, the Y-axis motor 77a, the intermediate presser motor 42, and the thread tensioner solenoid 82a, and executes sewing based on the sewing pattern data 71a.
For example, in the case of the sewing pattern data 71a shown in FIG. 8, the “intermediate presser height”, “thread tension”, and “sewing” commands, which are data related to the first stitch in the sewing pattern data, are input by the pedal R and The set values are read, and based on these, the intermediate presser motor 42, the thread tensioner solenoid 82a, the X-axis motor 76a, and the Y-axis motor 77a are driven with an operation amount corresponding to each set value. Further, the driving of the sewing machine motor 2a is started by reading the first “sewing” command.
After the start of driving of the sewing machine motor 2a, the main shaft angle is monitored by the count of the encoder 2b, and the command of each needle in the sewing pattern data 71a is read at a predetermined main shaft angle, and a predetermined value determined for each command. The operation of the controlled object is executed at the main shaft angle.

The rotational speed at the time of sewing of the sewing machine motor 2a and the torque value at the time of rotational driving are recorded in the data memory 71 as the command speed set from the operation panel 74, and the drive control of the sewing machine motor 2a is performed accordingly. To be done.
Further, regarding the positioning control of the holding frame 111 of the X-axis motor 76a and the Y-axis motor 77a, the operation period from the start to the stop of the frame movement is determined by the spindle angle. During the operation period, a table indicating the correspondence between the operation amount and the operation period is recorded in advance in the data memory 71 for each of the X-axis motor 76a and the Y-axis motor 77a. When the movement amount of the “sewing” command is read from the data 71a, the operation period is read with reference to the corresponding table, and the control of the motors 76a and 77a is executed by the operation start and end timings by the encoder 2b.

(Processing by frame position teaching program)
The frame position teaching program 70b is for confirming the operation based on the “sewing” and “intermediate presser height” commands of each needle in the sewing pattern data 71a and correcting the set value. In teaching based on the frame position teaching program 70b, the sewing motor 2a is not driven, and commands for each needle of the sewing pattern data 71a are sent to a forward key and a backward key (not shown) provided on the operation panel 74. Reproduce by executing one stitch at a time in the sewing order or reverse order according to the input. At this time, if the setting value needs to be corrected by the reproduction operation for each stitch, the operator selects the type of command through the operation panel 74 and corrects the setting value using the increase / decrease key. When there is such an input, the CPU 73 executes an operation control for performing a reproduction operation with a new set value for the corrected command. When confirmation is input, the sewing pattern data 71a is updated according to the correction content.
If the sewing pattern data 71a includes commands other than “sewing” and “intermediate presser height”, they can be reproduced and corrected in the same manner.

(Processing by intermediate presser height teaching program)
The intermediate presser height teaching program 70c is used to set the command and set value of the “intermediate presser height” and record the hardness of the sewing product for the sewing pattern data 71a. It is possible to set the intermediate presser height even when the frame position teaching program 70b described above is executed. However, in the case of the frame position teaching program 70b, the setting can be made by numerically inputting the intermediate presser height determined by the operator. Will be done.
On the other hand, when the intermediate presser height teaching program 70c is executed, a sewing object 108 is set in advance with the sewing needle 108 removed from the needle bar 108a by the operator in advance, and the sewing machine motor 2a is operated at a lower speed than during actual sewing. In the same manner as during sewing, the sewing operation is virtually performed in accordance with the sewing pattern data 71a. Then, by the vertical movement of the intermediate presser 29 at each needle drop position determined in the sewing pattern data 71a, the cloth thickness of the sewing product at each needle drop position is measured by a measurement process described later, and “ The “cloth holding height” command is automatically set in the sewing pattern data 71 a by the CPU 73.

The control performed by the CPU 73 by the intermediate presser height teaching program 70c will be described in detail with reference to FIGS.
FIG. 9 is a diagram (upper diagram) showing the change in the height of the intermediate presser 29 during the intermediate presser height teaching operation, and a diagram (lower diagram) showing the change in the shaft angle of the intermediate presser motor 42 at that time. . 9 indicates the upper surface height of the needle plate 110. The height P in the upper diagram is the target bottom dead center height of the intermediate presser 29 set in this intermediate presser height teaching. It shows. Further, the upper direction in the lower diagram shows the rotation angle in the direction in which the intermediate presser motor 42 moves the intermediate presser 29 upward.
10A is a point a in FIG. 9, FIG. 10B is a point bc section in FIG. 9, FIG. 10C is a point cd section in FIG. 9, and FIG. 9 is a schematic diagram showing an operation state of the intermediate presser height adjusting mechanism M4 at each intermediate presser height in the point ef section of FIG. In FIG. 10, for the sake of convenience, the bending directions of the links 20 and 22 and the arrangement of the intermediate presser motor 42 are reversed left and right for the sake of convenience, and the positioning link 13 is simplified for the sake of simplicity. The holding spring 16, which is a tension spring connected to one end portion of the second link 11 via the intermediate link, is omitted from the illustration of the positioning link 13 and is directly connected to the one end portion of the second link 11 as a pressing spring. Although shown, the functions are the same, and the following explanation of the principle has no effect.

During intermediate presser height teaching based on the intermediate presser height teaching program 70c, the X-axis motors 76a and Y are driven based on the sewing pattern data 71a while driving the sewing machine motor 2a at a lower speed than in the case of normal sewing. Confirmation operation control for reproducing the relative positioning operation of the sewing product for each stitch by driving the shaft motor 77a, and moving the intermediate presser 29 up and down at each position and pressing the sewing product by the intermediate presser 29 The height variable control to be suppressed and the thickness detection process for detecting the thickness of the sewing object when the intermediate presser 29 is lowered are performed.
Further, when the thickness of the sewing product is obtained in the thickness detection process, the thickness for recording the acquired thickness of the sewing product in association with the sewing pattern data 71a in the order of the number of stitches. A recording process is performed.
Thus, by executing the intermediate presser height teaching program 70c, the CPU 73 functions as a sewing control means, an intermediate presser height control means, a thickness acquisition processing means, and a thickness recording means.

(Medium presser height teaching program: Confirmation operation control)
Each control and each process will be described in more detail.
In the reproduction operation based on the sewing pattern data 71a, the CPU 73 drives the sewing machine motor 2a at a low speed with the sewing product set on the holding frame 111, and synchronizes with the sewing motor 2a. Accordingly, the holding frame 111 is positioned one by one.

(Medium presser height teaching program: Height variable control)
As described above, the intermediate presser 29 is moved up and down in synchronism with the sewing needle 108 so that the center presser vertical movement mechanism M1 has a top dead center at a main shaft angle of 0 ° and a bottom dead center at a main shaft angle of 180 °. . However, the intermediate presser 29 is disposed below the sewing needle 108, and the vertical reciprocating stroke thereof is also set shorter than that of the sewing needle 108.
Further, the intermediate presser height adjusting mechanism M4 can adjust the height of the intermediate presser 29 separately from the intermediate presser vertical movement mechanism M1. With respect to the intermediate presser motor 42 of the intermediate presser height adjusting mechanism M4, when the main shaft angle is 180 ° (bottom dead center), the angle of the output shaft when the bottom of the intermediate presser 29 becomes the same height as the top surface of the needle plate is 0 °. The following description will be given assuming that the origin is set.
In the height variable control, the CPU 73 sets the intermediate presser motor 42 to a predetermined target lowering position M (see FIG. 12) when the main shaft angle is 0 ° for each needle for the thickness acquisition process described later. Perform height adjustment control. The target lowering position M is such that the bottom of the intermediate presser 29 is higher than the upper surface of the needle plate 110 at the main shaft angle 0 ° (top dead center), and the bottom of the intermediate presser 29 is the needle at the main shaft angle 180 ° (bottom dead center). The position may be any position that is lower than the rod 110, but it is desirable that the position be as low as possible within a range that satisfies this condition. For example, if the bottom angle of the intermediate presser 29 is higher than the upper surface of the needle plate 110 when the main shaft angle is the top dead center, the minimum height within the adjustable range by the intermediate presser height adjustment mechanism M4 may be used. . Thus, the significance of adjusting the intermediate presser 29 to the low position for each needle will be described when the thickness acquisition process is described.

FIG. 11 is an explanatory diagram showing the relationship between the spindle angle and the type of control of the intermediate presser motor performed by the CPU 73. As shown in FIGS. 9 and 11, when the intermediate presser 29 receives a reaction force by stepping on the workpiece, the intermediate presser motor 42 receives one reaction of the vertical presser 29 (one rotation of the main shaft 2). A section for performing variable height control (height variable control section) K1 for rotating the output shaft in the upward movement direction and a section for performing maintenance control for maintaining the shaft angle of the intermediate presser motor 42 constant regardless of external force (maintenance) The control is roughly divided into (control section).
The maintenance control section includes a first maintenance control section K2 that maintains the shaft angle of the intermediate presser motor 42 at the origin between the main shaft angle 0 ° and the start main shaft angle of the height variable control section K1, and a variable height control. The second is to maintain the shaft angle of the intermediate presser motor 42 finally corrected by the height variable control between the end main shaft angle (180 °) of the section K1 and the main shaft angle 0 °. It is divided into the maintenance control section K3, and the shaft angle of the intermediate presser motor 42 is set to the aforementioned predetermined lowering target position at the main shaft angle (0 °) between the first maintenance control section K2 and the second maintenance control section K3. Return control is performed. Note that the control for returning the shaft angle of the intermediate presser motor 42 to the predetermined lowering target position may be performed at any timing from when the sewing needle comes out of the sewing product to when the height variable control is started.
In addition, in the variable height control section, the first maintenance control section, and the second control section, the spindle angle at the start and end of each section is recorded in the data memory 77 by setting in advance, and the CPU 73 is controlled by the encoder 2b. The spindle angle, which is the starting angle, is monitored and control for each section is started.

In order to explain the torque setting of the intermediate presser motor 42 in the height variable control section K1, the external torque applied to the output shaft of the intermediate presser motor 42 by each member of the intermediate presser vertical movement mechanism M1 and the intermediate presser height adjustment mechanism M4. explain.
First, as shown in the section bc of FIG. 10A and FIG. 9, when the intermediate presser 29 is positioned above the needle plate 110, the intermediate presser bar 28 is pressed by the pressing spring 30 to lower the pressing force f. The fourth link 22 connected to the intermediate presser bar 28 receives a counterclockwise torque T1 centered on the connecting end. As a result, the guide member 34 is given a clockwise torque T2 from the other end of the fourth link 22 through the square piece 33, and further, the intermediate presser motor from the guide member 34 through the moving link 36 and the eccentric cam 38. The output shaft 42 is provided with a clockwise torque Tf caused by the pressing spring 30. The external torque Tf rotates the output shaft of the intermediate presser motor 42 in the downward movement direction of the intermediate presser 29.
Thus, when the intermediate presser 29 is positioned above the needle plate 110, the torque Tf from the outside is applied to the output shaft of the presser motor 42, so in the height variable control section K1, The output shaft of the presser motor 42 is driven and controlled with an output of a drive torque Tm having a magnitude approximately equal to the external torque Tf in the reverse rotation direction (the upward movement direction of the intermediate presser 29).
As a result, the intermediate presser motor 42 is in a state where the external torque and the output torque are balanced, and the intermediate presser 29 by the intermediate presser height adjusting mechanism M4 is lowered while the intermediate presser 29 is lowered in the height variable control section K1. There is no change in height.

Further, as shown at a point c in FIG. 10B and FIG. 9, when the intermediate presser 29 has stepped on the sewing product in the height variable control section K <b> 1, the third link of the second link 11. On the other hand, since the first link 8 is pressed downward by driving the sewing machine motor 2 at the intermediate position of the second link 11, the second end of the second link 11 is pressed downward. The end portion that is the pivotal fulcrum of the link 11 is lowered against the tension spring 16. Thereby, clockwise torque T3 is given to the 2nd link 11 centering on the connection part with the 1st link 8, and the 3rd link 20 connected with the 2nd link 11 is the edge part on the square piece 33 side. Is received counterclockwise torque T4. As a result, the guide member 34 is given counterclockwise torque T5 from the end of the third link 20 via the square piece 33, and further, the intermediate presser motor is provided from the guide member 34 via the moving link 36 and the eccentric cam 38. A counterclockwise torque TF caused by the tension spring 16 is applied to the output shaft 42.
On the other hand, the external torque Tf caused by the pressing spring 30 described above disappears when the intermediate presser 29 comes into contact with the workpiece, and the external torque TF is applied in the same direction as the drive torque Tm of the intermediate presser motor 42. The output shaft of the intermediate presser motor 42 starts rotating, and rotates the guide member 34 counterclockwise as shown in the section cd in FIGS. 10C and 9. Thereby, the space | interval of the both ends of the connected 3rd link 20 and the 4th link 22 shrinks, and the press to the to-be-sewn material by the intermediate presser 29 is avoided. Further, since the distance between the both ends of the third link 20 and the fourth link 22 is reduced, the second link 11 is immediately turned clockwise so that the fulcrum side end is in contact with the regulating member 19. Therefore, although the external torque TF caused by the tension spring 16 disappears, the output shaft of the intermediate presser motor 42 is not given the external torque Tf caused by the press spring 30 that inhibits the rotation. Continues to rotate according to the drive torque Tm.
Since the rotation of the output shaft of the intermediate presser motor 42 continues until the main shaft angle reaches 180 ° (bottom dead center), which is the end angle of the height variable control section K1, a downward movement force is applied by the sewing machine motor 2. The press of the sewing product by the intermediate presser 29 is suppressed all the time.

Note that the output torque Tm of the intermediate presser motor 42 in the height variable control section K1 is set in the opposite direction to the external torque Tf caused by the press spring 30 and is set to the same magnitude. In the case of a sewing machine that does not exist, until the intermediate presser 29 comes into contact with the sewing product (for example, by losing the weight of each member or sliding friction of each part), it does not start to rotate in the upward direction. In addition, it is desirable to drive in the upward direction with a low torque that can transmit the vertical movement operation of the intermediate presser vertical movement mechanism M1 to the intermediate presser 29.
Note that the output torque Tm of the intermediate presser motor 42 in the height variable control section K1 may be arbitrarily adjusted by the operation panel 74 as torque setting means.

Further, as shown in FIG. 11, the maintenance control section in the height variable control described above is between the main shaft angle 0 ° and the start main shaft angle (section ab in FIG. 9) of the height variable control section K1. The first maintenance control section K2 for maintaining the shaft angle of the pressing motor 42 at the target lowering position M, and the main spindle angle 0 ° (section de in FIG. 9) from the end main spindle angle (in principle 180 °) of the height variable control section K1. ) Until the shaft angle of the intermediate presser motor 42 is maintained at the shaft angle of the intermediate presser motor 42 finally corrected by the variable height control. When shifting from K3 to the first maintenance control section K2, control is performed to return the shaft angle of the intermediate presser motor 42 to the target lowered position M at the main shaft angle (0 °).
In addition, in the variable height control section K1, the first maintenance control section K2, and the second control section K3, the spindle angles at the start and end of the sections are determined in advance, and the CPU 73 uses the encoder 2b to set the respective spindle angles. The spindle angle as the start angle is monitored and control for each section is started.

  In the first maintenance control section K2, the CPU 73 sets the command angle of the intermediate presser motor 42 to the angle of the target lowering position M (the intermediate presser 29 is at a height sufficiently lower than the upper surface of the needle plate at the bottom dead center. Control to maintain the shaft angle of the presser motor 42 is performed. Further, the CPU 73 performs current control so that the maintenance torque of the output shaft of the intermediate presser motor 42 at that time is larger than the external torque TF by the tension spring 16 (F> f, TF> Tf). Thereby, even if the intermediate presser 29 is inadvertently prevented from descending due to any object being caught in the first maintenance control section, the output shaft of the intermediate presser motor 42 maintains the angle of the target lowering position M and is pulled. The escape operation performed when the spring 16 extends and the lowering operation of the intermediate presser 29 is inhibited is performed.

Further, in the second maintenance control section K3, as shown in FIG. 10D and FIG. 9d-e section, the CPU 73 finally moves the intermediate presser motor 42 in the height variable control section K1 until the top dead center is reached. Control to maintain the angle reached. Also in this case, the CPU 73 performs current control so that the maintenance torque of the output shaft of the intermediate presser motor 42 becomes the same value as in the first maintenance control section.
As a result, when the sewing needle 108 that has passed through the bottom dead center starts to rise while being stabbed into the sewing product, the sewing product is pulled by the sewing needle 108 and comes into pressure contact with the intermediate presser 29. Since No. 29 maintains a certain height against the pressing force, it is possible to prevent the workpiece from being lifted.

  Further, when the intermediate presser 29 reaches the top dead center in the second maintenance control section K3 (point e in FIG. 9), the CPU 73 performs control to return the intermediate presser motor 42 to the angle of the target lowering position M (FIG. 10). (E) and point f) in FIG. That is, in the height variable control section K1, when the intermediate presser 29 is in contact with the workpiece and the shaft angle of the intermediate presser motor 42 is changed, the angle is returned to the target lowered position M. As a result, even when the thickness of the sewing product becomes thin during the next variable height control, it is possible to avoid the situation where the intermediate presser 29 does not reach the sewing product and to set the proper bottom dead center height. Therefore, it is possible to prevent the workpiece from being lifted in the second maintenance control section K3 thereafter.

Note that both the main shaft angle (point b in FIG. 9) and the main shaft angle (point d in FIG. 9) at the beginning of the height variable control section K1 can be input and set from the operation panel 74.
The start angle of the variable height control can be set within a range of 0 ° or more and 180 ° or less, and at least the angle at which the intermediate presser 29 starts the variable height control from the height that can be taken by the sewing product. It shall be set.
In principle, the end angle is set to the bottom dead center of the vertical movement by the sewing machine motor 2 (main shaft angle 180 °). Even after 180 °, the end angle can be finely adjusted, for example, to about 190 °. It is.
Thus, the operation panel 74 functions as “section setting means for setting the start and end spindle angles of the section in which the height variable control is performed”.

(Medium presser height teaching program: thickness acquisition processing and thickness recording processing)
FIG. 12 is an explanatory diagram of the principle in the thickness acquisition process.
The thickness acquisition process is performed when the intermediate presser 29 moves up and down. As described above, in the variable height control, the intermediate presser motor 42 is controlled so as to reach the predetermined target lowering position M at the main shaft angle of 0 ° for each needle.
The middle presser 29 shown by the two-dot chain line in FIG. 12A shows a state at the target lowering position M (note that since the needle plate 110 exists, the intermediate presser 29 is actually lowered so far. Is impossible, and the target lowering position M is merely a setting position).
When the main shaft angle is at the top dead center in advance, the main shaft angle is reduced by driving the sewing machine motor 2 while the height of the intermediate presser 29 is lowered by the intermediate presser motor 42 so as to reach the target lowering position M. When rotating to the bottom dead center, the intermediate presser 29 comes into contact with the needle plate 110 in the middle of lowering, so that the output shaft of the intermediate presser motor 42 is adjusted between the target lowering position M and the needle plate 110 by variable height control. The rotation is caused by an angle α ° according to the difference.
On the other hand, as shown in FIG. 12 (B), when the lowering operation of the intermediate presser 29 is performed when the workpiece is present on the upper surface of the needle plate 110, the output shaft of the intermediate presser motor 42 is controlled by the height variable control. However, the rotation is caused by an angle β ° according to (the height difference between the target lowering position M and the upper surface of the needle plate 110) + (the thickness of the sewing product).
Therefore, by registering the target lowering position M in the data memory, the CPU 72 calculates the angle α of the intermediate presser motor 42 in advance, detects the rotation angle β from the encoder 81 of the intermediate presser motor 42 for each stitch, By obtaining the difference β−α, it is possible to detect the thickness of the sewing product for each stitch of the sewing pattern data 71a. It should be noted that a table indicating the relationship between the angle difference β−α and the thickness of the sewing product may be prepared in the data memory 71 and referred to.
In the thickness acquisition process, the rotation angle β may be recorded in advance for all needle drop positions in advance, and then the thickness of the sewing product for all needle drop positions may be obtained.

In the thickness recording process, the CPU 72 performs a process of recording the thickness of the sewing product for each needle obtained in the thickness acquisition process in the corresponding sewing pattern data 71a. At that time, the number of stitches and the thickness of the sewing product are recorded in correspondence.
In the thickness recording process, the thickness of the sewing product is first obtained for all needle drop positions in the thickness acquisition process in advance, and then the thickness of the sewing product for all needle drop positions is set as the sewing parameter 71a. It may be recorded.

In the thickness recording process, the actually measured thickness of the sewing object is recorded with respect to the sewing pattern data 71a. Therefore, when the intermediate presser height teaching is started, the thickness is already recorded in the sewing pattern data 71a. All data of the intermediate presser height command and its set value are deleted in advance.
In addition, the thickness of the sewing product for each stitch determined by the thickness acquisition process was compared with the thickness of the sewing product at the previous needle drop position, resulting in a change of more than the predetermined thickness. Only in this case, the sewing pattern data 71a may be recorded.
Further, when the detected thickness of the sewing product is recorded in the sewing pattern data 71a, correction by adding an arbitrarily set correction value may be possible.

(Explanation of operation in teaching of the middle presser height of the sewing machine)
FIG. 13 is a flowchart showing the control of the basic operation before teaching the intermediate presser height, and FIG. 14 is a flowchart when the intermediate presser height teaching mode is selected and executed from the basic operation.
Based on these FIG. 13 and FIG. 14, the control and processing performed by the CPU 73 by the execution of the intermediate presser height teaching program 70c will be described.

First, as shown in FIG. 13, when a preparation key that prompts execution of operation control such as sewing and teaching displayed on the operation panel 74 is pressed (step S <b> 11), the CPU 72 detects this and detects data. Reading of the sewing pattern data 71a in the memory 71 is executed (step S12).
Next, an execution operation selection screen is displayed on the operation panel 74 to allow the operator to select one of the sewing, frame position teaching, and intermediate presser height teaching modes.
When the operator selects the intermediate presser height teaching mode (step S13), the CPU 72 controls the cloth presser motor 79a to stand by with the holding frame 111 raised, and the operator sets the sewing product. Set to wait state. Then, a cloth presser lowering execution key is displayed on the operation panel 74, and when the lowering execution key is pressed (step S14), the CPU 72 starts processing in the intermediate presser height teaching mode (step S15).

FIG. 14 shows processing in the intermediate presser height teaching mode. This process is repeatedly performed with a short cycle (for example, repeated every time the spindle angle changes by 1 °) during execution of the intermediate presser height teaching.
First, the CPU 72 starts driving the sewing machine motor 2a and detects the current main shaft angle from the output of the encoder 2b (step S21).
Then, it is determined whether or not the current main shaft angle is the height variable control section K1 (step S22). If it is within the section, the height variable control is executed (step S23).

That is, the CPU 72 controls the intermediate presser motor 42 so that the drive torque Tm is output in the upward rotation direction of the intermediate presser 29. As a result, the output shaft of the intermediate presser motor 42 balances the downward external torque Tf based on the pressing spring 30 and the drive torque Tm, and the intermediate presser height adjusting mechanism M4 does not move up and down. The intermediate presser 29 moves downward according to the lowering motion applied to the intermediate presser vertical movement mechanism M1 (see FIG. 10A).
When the descending intermediate presser 29 comes into contact with the sewing product, an external torque TF on the rising side based on the tension spring 16 is momentarily applied to the output shaft of the intermediate presser motor 42, and the output shaft of the intermediate presser motor 42 is Rotation occurs on the ascending side (see FIGS. 10B and 10C). During this time, the intermediate presser vertical movement mechanism M1 imparts a lowering operation to the intermediate presser 29, while the intermediate presser height adjusting mechanism M4 gives or allows the upward movement, and the vertical movement of the intermediate presser 29 is offset. Therefore, the sewing product is hardly pressed.

Next, the CPU 72 refers to the encoder 2b to determine whether or not the spindle angle is the needle lowest point (bottom dead center: 180 °) (step S24). If it is not the needle lowest point, the CPU 72 proceeds to step S26. Proceed with the process.
When the main shaft angle is the needle lowest point, the rotation angle β after the intermediate presser 29 comes into contact with the sewing product is detected from the output of the encoder 81 of the intermediate presser motor 42 (step S25). . Further, the CPU 72 calculates the fabric thickness of the sewing product from β-α, generates an intermediate presser height command for the number of stitches at that time from the fabric thickness, stores it in the sewing pattern data 71a, and performs the process in step S26. To proceed.
In step S26, the CPU 72 determines whether or not the sewing needle vertical movement has been completed for all the numbers of needles stored in the sewing pattern data 71a. If completed, the CPU 72 ends the process and does not complete it. In that case, the process returns to step S21.

If it is determined in step S22 that the main shaft angle is not within the height variable control section K1, the CPU 72 further determines whether or not the main shaft angle is 0 ° (top dead center) (step S22). S27) If the angle is 0 °, the intermediate presser motor 42 is controlled to reach the target lowered position M (step S28), and the process proceeds to step S26.
When the main shaft angle is not 0 °, control is performed so that the output shaft of the intermediate presser motor 42 maintains the current angle (step S29), and the process proceeds to step S26.

  With this process, when the main shaft angle is within the variable height control section K1 in one rotation of the main shaft, the processes of steps S21, 22, 23, 24, 25, and 26 are repeated to execute the variable height control. Therefore, when the main shaft angle is within the first or second maintenance control section K2, K3 (except for the case of 0 °), the processes of steps S21, 22, 27, 29, and 26 are repeated. When the main shaft angle is 0 °, the processing of steps S21, 22, 27, 28, and 26 is executed, so that the main shaft angle of the intermediate presser motor 42 is set to the target lowering position M. Control will be executed.

(Effect of embodiment)
In the electronic cycle sewing machine 100, the control shaft 1000 rotates the output shaft in a direction in which the intermediate presser motor 42 moves the intermediate presser 29 upward by variable height control when the intermediate presser 29 is brought into contact with the workpiece by lowering the intermediate presser 29. Therefore, pressing of the sewing product is avoided.

Further, in the control device 1000, the intermediate presser height when the intermediate presser 29 is at the bottom dead center (main shaft angle 180 °) at the main shaft angle 0 ° before the start of the variable height control is greater than the upper surface of the needle plate 110. Also, the intermediate presser motor 42 is controlled so as to be on the lower side.
Thus, when the intermediate presser 29 is moved up and down, if the height at the bottom dead center (main shaft angle 180 °) of the intermediate presser 29 is set to coincide with the upper surface of the needle plate 110, the material to be sewn is thin. In this case, the intermediate presser 29 comes into contact with the sewing product immediately before the main shaft angle 180 °, and the intermediate presser before the rotation of the output shaft of the intermediate presser motor 42 is started by the variable height control. Turning to the raising of the intermediate presser 29 by the vertical movement mechanism M1, the angle change due to the variable height control of the output shaft of the intermediate presser motor 42 cannot be obtained satisfactorily, and as a result, the thickness detection of the sewing product is good. Cause problems that cannot be done.
In particular, in the case of a structure having a pressing spring for avoiding excessive load, such as the tension spring 16 of the urging mechanism M2, in the case of a thin sewing product, due to the extension of the tension spring 16 that occurs instantaneously at the time of contact. The driving of the intermediate presser motor corresponding to the thickness of the sewing product is absorbed, and it may be difficult to detect the thickness by the intermediate presser motor 42 well.
However, in the electronic cycle sewing machine 100, since the target lowering height M of the intermediate presser 29 is set to a lower height away from the needle plate 110, the lowering intermediate presser 29 is covered at a timing considerably faster than the main shaft angle 180 °. It can be brought into contact with the sewing product, and after the contact, the lowering operation continues to be applied by the intermediate presser motor vertical movement mechanism M1, and as a result, the output shaft of the intermediate presser motor 42 rotates sufficiently. That is, it is possible to avoid a situation in which the intermediate presser 29 is turned back before the output shaft of the intermediate presser motor 42 is rotated. As a result, even if the sewing product is a thin material, Even if there is a pressing spring for avoiding excessive load, it is possible to detect the thickness satisfactorily.

Further, in the electronic cycle sewing machine 100, the thickness of the workpiece can be obtained without using a cloth thickness detector that performs contact position detection, distance detection, and the like, and the productivity can be improved by reducing the number of parts. It becomes possible. Also, without using the cloth thickness detector that detects the contact position or distance, the cloth thickness is detected by bringing the intermediate press into contact with the workpiece. The cloth thickness in a state compressed with the sewing thread can be detected, and the sewing quality can be improved.
Furthermore, since the press at the time of contact with the sewing product due to the intermediate presser is suppressed by the intermediate presser motor 42, it is possible to avoid pressing and damaging the sewing product, and to improve the sewing quality by protecting the sewing product. Is possible.

  Further, in the electronic cycle sewing machine 100, the height variable control is executed in synchronization with the relative positioning operation of the sewing object for each needle executed according to the sewing pattern data 71a, and the thickness acquisition process of each needle is executed. Since the thickness of the workpiece is recorded in the sewing pattern data 71a in association with the number of stitches, the height of the intermediate presser 29 is adjusted to the sewing product one by one while Compared with the case where the setting work of the sewing pattern data 71a is performed by setting the dead point height, the complicated pattern setting work is not required, the work load is reduced, and the sewing pattern data 71a in consideration of the thickness of the sewing product is obtained. It can be easily acquired.

(Other)
In the electronic cycle sewing machine 100, the height variable control and the thickness of the workpiece are detected at the time of intermediate presser height teaching. However, in the normal sewing, the height variable control and the thickness of the workpiece are controlled. Detection of the length may be performed.

It is a perspective view which shows the sewing machine which concerns on this invention. It is an expansion perspective view which shows the holding frame of a sewing machine, and the vicinity of intermediate pressing. It is a side view which shows the intermediate press apparatus of a sewing machine. It is a disassembled perspective view of an intermediate pressing device. It is a disassembled perspective view of an intermediate pressing device. It is explanatory drawing regarding the height adjustment of the intermediate presser of the intermediate press device, FIG. 6 (a) shows a case where the bottom dead center is adjusted downward, and FIG. 6 (b) abuts the bottom dead center for adjustment. Show the case. It is a block diagram which shows the control apparatus of the sewing machine which concerns on this invention. It is explanatory drawing which shows the data structure of sewing pattern data. FIG. 6 is a diagram showing a change in the height of the intermediate presser during the intermediate presser height teaching operation and a diagram showing a change in the shaft angle of the intermediate presser motor 42 at that time. 10A is a point a in FIG. 9, FIG. 10B is a point bc section in FIG. 9, FIG. 10C is a point cd section in FIG. 9, and FIG. FIG. 10E is a schematic diagram showing the operation state of the intermediate presser height adjusting mechanism at each intermediate presser height in the point ef section of FIG. It is a schematic diagram for demonstrating the torque load which the press spring of an intermediate presser height adjustment mechanism brings to an intermediate presser motor. FIGS. 12A and 12B are diagrams illustrating the principle of thickness acquisition processing. FIG. 12A shows a case where there is no sewing product on the needle plate, and FIG. 12B shows a case where there is a sewing product on the needle plate. . It is a flowchart which shows control of the basic operation before intermediate presser height teaching. 14 is a flowchart when the intermediate presser height teaching mode is selected and executed from the basic operation of FIG.

Explanation of symbols

1 Intermediate presser 2 Spindle 2a Sewing machine motor 2b Encoder (Spindle angle detection means)
11 Second link (other motion transmission member)
16 Tension spring 20 Third link (motion transmission member)
22 4th link (motion transmission member)
29 Intermediate presser 30 Pressing spring 42 Intermediate presser motor 70a Sewing program 70c Intermediate presser height teaching program 71a Sewing pattern data 73 CPU (sewing control means, intermediate presser height control means, thickness acquisition processing means, thickness recording means)
76a X-axis motor (positioning motor)
77a Y-axis motor (positioning motor)
81 Encoder (Motor shaft angle detection means)
DESCRIPTION OF SYMBOLS 100 Electronic cycle sewing machine 110 Needle plate 1000 Control apparatus M1 Middle presser vertical movement mechanism M2 Energizing mechanism M3 Middle presser retraction mechanism M4 Middle presser height adjustment mechanism

Claims (3)

A needle up-and-down movement mechanism that moves the sewing needle up and down with a sewing machine motor;
A positioning mechanism for relatively positioning the sewing needle and the workpiece by a positioning motor;
Storage means for storing sewing pattern data including position information for determining the relative position of the sewing object with respect to the sewing needle for each stitch;
Spindle angle detection means for detecting the angle of the spindle that is rotationally driven by the sewing machine motor;
An intermediate presser that prevents the sewing product from lifting when sewing,
An intermediate presser vertical movement mechanism that obtains power from the sewing machine motor and moves the intermediate presser up and down in synchronization with the vertical movement of the sewing needle;
An intermediate presser height adjusting mechanism that moves the intermediate presser up and down separately from the sewing machine motor by changing the posture of the motion transmitting member of the intermediate presser vertical movement mechanism by the intermediate presser motor and supporting the post-change posture. When,
In a sewing machine comprising sewing control means for driving a positioning mechanism for each stitch according to the sewing pattern data while synchronizing with the raising and lowering of the intermediate presser performed by the intermediate presser vertical mechanism by driving the sewing machine motor,
Motor shaft angle detection means for detecting the angle of the output shaft of the intermediate press motor;
From the start of lowering of the intermediate presser or during the lowering to the bottom dead center, the posture of the motion transmitting member is maintained so as not to change the vertical position by the intermediate presser height adjusting mechanism, When the torque from the outside is applied to the output shaft of the intermediate presser motor by contact with the sewing product, the variable height control for controlling the output of the intermediate presser motor so as to rotate in the direction in which the intermediate presser is moved upward. Intermediate presser height control means for performing,
A thickness acquisition processing means for performing a thickness acquisition process for obtaining a thickness of the sewing product from a detection angle of an output shaft angle of the intermediate presser motor at the bottom dead center of the intermediate presser,
The intermediate presser height control means controls the intermediate presser motor before the height variable control so that the intermediate presser height is lower than the upper surface of the needle plate when the intermediate presser is at the bottom dead center. A sewing machine characterized by   2. The sewing machine according to claim 1, further comprising a thickness recording unit that records the acquired thickness of the sewing product in association with the sewing pattern data in the order of the number of stitches.   The other motion transmission member is supported by an elastic force while the intermediate presser vertical movement mechanism is supported by an elastic force, and the lowering of the intermediate presser is hindered to cause a load on the other motion transmission member to occur. 3. The sewing machine according to claim 1, further comprising a pressing spring for avoiding an excessive load on the intermediate presser vertical movement mechanism that allows the operation transmitting member to escape.

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