JP2012080942A - Sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a differential feeding.SOLUTION: A sewing machine comprises: detection means 91,81 of upper cloth and bottom cloth for detecting end portions of an upper cloth CU and a bottom cloth CD to be conveyed; a feeding adjustment mechanism 9 of upper cloth for pressing only the upper cloth to be fed; a feeding adjustment mechanism 5 of bottom cloth for providing pressure only on the bottom cloth to be fed; a position calculation part 51 of end portion for calculating a differential feeding based on a feed amount of a cloth feeding mechanism and a detection timing of each detection means; a recording part 54 for recording the amount of the differential feeding in connection with a difference of pressure between the upper cloth and the bottom cloth when the differential feeding occurs; and an adjustment control part 51 for controlling the upper cloth feeding adjustment mechanism and the bottom cloth feeding adjustment mechanism so as to generate an appropriate difference of the pressure between the upper cloth and the bottom cloth in a subsequent sewing process by calculating the appropriate difference of pressure between the upper cloth and the bottom cloth based on records from two or more sewing with regard to the differential feeding and the difference of the pressure between the upper cloth and the bottom cloth, in the recording part.

Description

  The present invention relates to a sewing machine that eliminates misalignment of the end portions of two pieces of fabric to be sewn together.

When two upper and lower fabrics are overlapped and sewn, the end portions of the upper and lower fabrics may be misaligned and the fabric ends may not match (FIGS. 16A and 16B).
Therefore, the conventional sewing machine includes an adjustment mechanism that presses only the upper cloth, an adjustment mechanism that presses only the lower cloth, a sensor that detects the feed speed of the upper cloth, and a sensor that detects the feed speed of the lower cloth. When the sensor detects that the feeding of one of the fabrics precedes, control for increasing the pressing force on the fabric and adjusting the feeding speed is performed (for example, see Patent Document 1). ).

JP 59-174189 A

  However, when the method for controlling the pressing force of the fabric by monitoring the feeding speed as described above is taken, depending on the type of the fabric, the fabric may be stretched or contracted, and even if the feeding speed is adjusted by the pressing force, the sewing end is completed. In some cases, the end-of-line shift could not be resolved.

  An object of the present invention is to more reliably prevent the displacement of the end of the fabric.

The invention described in claim 1
A cloth feeding mechanism for feeding the upper cloth and the lower cloth in a predetermined feeding direction;
An upper cloth detecting means for detecting an end portion of the upper cloth sent by the cloth feeding mechanism;
A lower cloth detecting means for detecting an end portion of the lower cloth sent by the cloth feeding mechanism;
An upper cloth feed adjusting mechanism that applies a pressing force only to the upper cloth for the feed operation by the cloth feed mechanism;
In a sewing machine comprising a lower cloth feed adjusting mechanism that applies a pressing force only to the lower cloth for the feed operation by the cloth feed mechanism,
An end portion position calculating unit that calculates a shift amount between the end portions of the upper cloth and the lower cloth based on the feed amount of the cloth feed mechanism and the detection timing of the upper cloth detecting means and the lower cloth detecting means;
A recording unit that records the amount of deviation and the difference in pressing force between the upper cloth and the lower cloth when the deviation occurs; and
The appropriate difference between the pressing force of the upper cloth and the lower cloth is obtained from the record of the deviation amount and the difference between the pressing forces of the upper cloth and the lower cloth due to two or more sewings of the recording portion, and the appropriate difference is obtained during the subsequent sewing. And an adjustment control for controlling the upper cloth feed adjusting mechanism or the lower cloth feed adjusting mechanism so as to cause a difference in pressing force between the upper cloth and the lower cloth.

  The invention according to claim 2 has the same configuration as that of the invention according to claim 1, and the adjustment control section records three or more records of the amount of deviation due to sewing and the difference in pressing force between the upper cloth and the lower cloth. In some cases, the correspondence between the amount of displacement and the difference in pressing force between the upper and lower fabrics is calculated by the least square method, and the appropriate difference in pressing force between the upper and lower fabrics is calculated based on the corresponding relationship. It is characterized by doing.

The invention of claim 3 has the same configuration as that of the invention of claim 1 or 2,
The end position calculation unit calculates a deviation amount between the end portions of the upper cloth and the lower cloth based on a principal axis angle when the end positions of the upper cloth and the lower cloth are detected. .

The invention according to claim 4 has the same configuration as that of the invention according to claim 3,
An operation panel for inputting the feed pitch,
For each feed pitch that can be input by the operation panel, a data table is provided in which the spindle angle and the feed amount of the cloth feed mechanism are associated with each other.

The invention according to claim 5 has the same configuration as the invention according to any one of claims 1 to 4,
When the adjustment control unit performs control so as to generate a difference in pressing force between the appropriate upper cloth and lower cloth, the upper cloth feed adjustment mechanism, the lower cloth feed adjustment mechanism, or both are controlled. It is selectable.

  According to the first aspect of the present invention, when a record of the amount of deviation due to the past two or more sewings and the difference between the pressing force of the upper cloth and the lower cloth is obtained, a mutual correspondence is obtained therefrom, whereby the deviation amount is obtained. It is possible to calculate the difference between the pressing force of the upper cloth and the lower cloth that becomes 0 by calculation. Therefore, since the appropriate difference between the pressing force of the upper and lower fabrics is specified by the actual amount of displacement between the upper and lower fabrics, even if each fabric is stretched or shrunk or slipped, its effect Therefore, it is possible to perform high-quality sewing with less occurrence of deviation.

In the invention according to claim 2, the adjustment control unit calculates the correspondence between the amount of deviation and the difference between the pressing force of the upper cloth and the lower cloth by the least square method, and calculates the appropriate difference between the pressing force of the upper cloth and the lower cloth. Since the calculation is performed, it is possible to obtain an appropriate difference in pressing force even when a record of the amount of deviation due to three or more sewings and the difference in pressing force between the upper cloth and the lower cloth is acquired.
Each time a record of the amount of deviation due to new sewing and the difference in pressing force between the upper and lower fabrics is obtained, a more appropriate difference in pressing force can be obtained. Quality can be further improved.

According to the third and fourth aspects of the present invention, since the shift amount between the end portions of the upper and lower fabrics is calculated from the main shaft angle when the fabric end position is detected, the shift amount can be calculated more accurately.
Since the upper cloth feed adjusting mechanism or the lower cloth feed adjusting mechanism to be controlled can be selected, the invention according to claim 5 can perform optimum control for various sewing products.

It is a perspective view of a vertical feed sewing machine. It is a schematic diagram which shows the needle drop vicinity. It is the perspective view which showed the mechanism regarding the drive of each roller. It is a perspective view of a cloth sensor. It is a schematic diagram explaining the detection of a cloth sensor. It is a block diagram which shows the structure around a control apparatus. It is explanatory drawing which shows the relationship between the locus | trajectory of feed operation of a feed dog, and the rotation angle of a sewing machine main shaft. It is the diagram which showed the change of the cumulative cloth feed amount with respect to continuous rotation of the main spindle of the sewing machine. It is a conceptual diagram which shows that the difference of the pressing force of each cloth with the amount of feeding is matched and recorded. A line plotted in accordance with the obtained amount of the shearing amount obtained by sewing and the pressing force of the upper and lower cloths, with the X axis as the difference between the pressing forces of the upper cloth CU and the lower cloth CD and the Y axis as the amount of the feeding. FIG. It is a flowchart which shows the whole process at the time of sewing of a vertical feed sewing machine. It is a flowchart which shows the subroutine of an upper cloth / lower cloth information acquisition process. It is a flowchart which shows the subroutine of the amount calculation process. It is a flowchart which shows the subroutine of an appropriate pressing force difference calculation process. It is a flowchart which shows the subroutine of a pressing force difference setting process. When two upper and lower fabrics are overlapped and sewn, the end of the upper and lower fabrics is misaligned and the fabric ends do not match. FIG. 16A shows that the lower fabric is long. FIG. 16B shows a case where the upper cloth becomes longer.

(Configuration of vertical feed sewing machine)
An embodiment of a vertical feed sewing machine 100 according to the present invention will be described.
This vertical feed sewing machine 100 sews the upper cloth CU and the lower cloth CD placed on the throat plate while feeding them in the same direction.
As shown in FIGS. 1, 2, and 3, the vertical feed sewing machine 100 includes a cloth presser 19, a feed dog 1, a feed leg 2, a lower roller 3, a lower pulse motor 4, and a lower cloth feed adjustment mechanism. 5, an upper roller 7, an upper pulse motor 8, an upper cloth feed adjusting mechanism 9, a separation plate 11, lower and upper cloth sensors 80 and 90, and a control device 13.

(Feed dog)
As shown in FIG. 2, the feed dog 1 performs a feeding operation by contacting the lower cloth CD from below, out of the two cloths placed on the needle plate 14. The feed dog 1 is driven by a feed dog forward / backward feed mechanism (not shown) that gives a reciprocating motion along the cloth feed direction and a feed dog vertical feed mechanism (not shown) that gives a reciprocating motion along the vertical direction. . Thereby, the feed dog 1 moves so as to draw an elliptical orbit in a side view below the needle plate 14, and protrudes from the needle plate 14 and contacts the lower cloth CD from below when the feed dog 1 moves upward. Hereinafter, the cloth feeding direction by the feed dog 1 is F.
The feed dog 1 and the mechanism that imparts the operation to the feed dog 1 constitute a cloth feed mechanism.

(Cloth presser and feed leg)
As shown in FIG. 2, the feeding foot 2 performs a feeding operation by touching the upper cloth CU from above, out of the two cloths placed on the needle plate 14, and the cloth presser 19 is moved to the upper cloth CU. Press the cloth down from above. The feed foot 2 is driven by a feed foot forward / backward feed mechanism (not shown) that gives a reciprocating motion along the cloth feed direction and a feed foot vertical feed mechanism (not shown) that gives a reciprocating motion along the vertical direction. The cloth presser 19 only moves up and down by the above-mentioned feed leg up-and-down feed mechanism. Thereby, the feed leg 2 moves to draw an elliptical orbit in a side view above the needle plate 14, and comes into contact with the upper cloth CU from above when the feed leg 2 moves downward. Further, the cloth presser 19 moves up and down alternately with the feed leg 2 at a fixed position. That is, while the cloth presser 19 is separated above the upper cloth CU, the feed leg 2 moves downward while moving the feed foot 2 to perform the upper cloth CU feeding operation, and the cloth presser 19 is moved to the upper cloth CU. While in contact, the feed leg 2 moves upward while returning to the upstream side in the feed direction.
The sewing needle moves up and down at the position of the cloth presser 19 and moves up and down together with the cloth presser 19.
The feed foot 2 and the mechanism that imparts an action to the feed foot 2 constitute a cloth feed mechanism.

(Lower roller)
As shown in FIGS. 2 and 3, the lower roller 3 is disposed in the concave hole of the needle plate 14 so as to be movable up and down, and is provided so as to protrude somewhat from the upper surface of the needle plate 14 when raised. The cloth is moved in contact with the cloth CD from below and in a direction intersecting (orthogonal to) the cloth feeding direction F by the feed dog 1 and parallel to the upper surface of the needle plate 14. The lower roller 3 is rotatably supported by a lower cloth feed adjusting mechanism 5 (details will be described later). The lower roller 3 is rotatably supported at the distal end portion of the swing arm 17, and a lower pulse motor 4 is provided at the base end portion of the swing arm 17 via a base 16. The lower roller 3 is rotated by a belt passing from the lower pulse motor 4 through the inside of the swing arm 17.
The lower roller 3 applies a moving force to the lower cloth CD in a direction G (hereinafter also referred to as a left-right direction) orthogonal to the cloth feeding direction F by rotation, and the direction of the seam formed on the lower cloth CD is set to the left and right. It is possible to control.

(Under cloth feed adjustment mechanism)
As shown in FIG. 3, the lower cloth feed adjustment mechanism 5 includes the base 16 and the swing arm 17, the rotating shaft 21, the drive lever 22, the transmission link 23, and the lower solenoid 6.
The base 16 to which the lower pulse motor 4 is fixed is formed in a pentagonal shape, and a rotating shaft 21 is provided at one corner thereof.
The rotating shaft 21 is rotatably supported by the sewing machine frame, and the direction of the shaft is parallel to the output shaft of the lower pulse motor 4. One end thereof is fixed to the base 16, and the base 16 rotates with the rotation of the rotary shaft 21. A drive lever 22 is provided at the other end of the rotating shaft 21.
The drive lever 22 is a rod-like plate material extending in the radial direction with the rotation shaft 21 as the center, and the rotation shaft 21 is clamped and fixed at one end thereof. One end of the transmission link 23 is connected and fixed to the other end of the drive lever 22 with a screw or the like.
The transmission link 23 is a plate material extending in the extending direction of the drive lever 22, and the plunger 62 of the lower solenoid 6 is connected to the other end of the transmission link 23.

  The lower solenoid 6 is arranged such that the plunger 62 moves along the vertical direction of the sewing machine (the vertical direction of the needle). The lower solenoid 6 changes the amount of movement of the plunger 62 in accordance with the amount of current that is energized. Thereby, the lower solenoid 6 can adjust the pressing force with respect to the lower cloth CD via the lower roller 3 in accordance with the energized current amount.

The lower solenoid 6 is attached in a direction to drive the plunger 62 in a direction in which the plunger 62 is drawn by energizing the coil. Then, the thrust for pulling the plunger 62 is increased as the energization current increases.
The lower solenoid 6 generates a thrust proportional to the square of the applied current. That is, the amount of change in thrust with respect to current change increases as the generated thrust increases. For this reason, a small amount of change can be obtained with a small thrust, and a slight change in pressing force can be achieved. With a large thrust, a large amount of change can be obtained and the pressing force can be changed with a relatively large width. The pressing force can be easily adjusted.

(Upper roller)
As shown in FIGS. 2 and 3, the upper roller 7 is provided above the needle plate 14 so as to be movable up and down, and comes into contact with the upper cloth from above when intersecting with the cloth feeding direction F by the feed dog 1 ( The cloth is moved in a direction orthogonal to the upper surface of the needle plate 14. The upper roller 7 is rotatably supported by an upper cloth feed adjusting mechanism 9 (details will be described later). The upper roller 7 is rotatably supported at the distal end portion of the swing arm 32, and the base end portion of the swing arm 32 is supported by a belt passing through the inside of the swing arm 32 from the upper pulse motor 8 via the base 31. Rotation is given.
The upper roller 7 applies a moving force to the upper cloth CU in the direction G perpendicular to the cloth feeding direction F by rotation, and can control the direction of the seam formed on the upper cloth CU to the left and right.

(Upper cloth feed adjustment mechanism)
The upper cloth feed adjusting mechanism 9 includes the base 31 and the swing arm 32, the rotation shaft 33, the drive lever 34, the transmission link 35, the rotation link 36, and the upper solenoid 10.
The base 31 to which the upper pulse motor 8 is fixed is formed in a pentagonal shape, and a rotation shaft 33 is provided at one corner thereof.
The rotating shaft 33 is rotatably supported by the sewing machine frame, and the direction of the shaft is parallel to the output shaft of the upper pulse motor 8. One end of the base 31 is fixed to the base 31, and the base 31 rotates with the rotation of the rotary shaft 33. A drive lever 34 is provided at the other end of the rotating shaft 33.
The drive lever 34 is a plate material extending in the radial direction around the rotation shaft 33, and the rotation shaft 33 is clamped and fixed at one end thereof. One end of a transmission link 35 is rotatably connected to the other end of the drive lever 34.
The transmission link 35 is a rod-like plate material extending in a direction substantially orthogonal to the drive lever 34, and one end portion of the rotation link 36 is rotatably connected to the other end portion of the transmission link 35.
The rotary link 36 is rotatably supported by a plate material 71 attached to the housing 70 of the upper solenoid 10 in the vicinity of the center portion thereof. The other end of the rotary link 36 is rotatably connected to a plunger 72 that serves as an output shaft of the upper solenoid 10. The rotary link 36 is disposed substantially parallel to the drive lever 34.

The upper solenoid 10 is arranged such that the plunger 72 moves along the moving direction (longitudinal direction) of the transmission link 35.
The upper solenoid 10 includes a housing 70, a plunger 72, and the like, and the amount of movement of the plunger 72 changes according to the amount of current that is energized. Thereby, the upper solenoid 10 can adjust the pressing force with respect to the upper cloth CU via the upper roller 7 in accordance with the amount of energized current.

(Separator)
As shown in FIG. 1, one end of the separation plate 11 is fixed to the bottom surface of the support plate 44 with a screw (not shown). The support plate 44 is connected to an adjustment dial 45 shown in FIG. 1 via a rack and a pinion gear (not shown). When the adjustment dial 45 is rotated, the position of the separation plate 11 is adjusted with respect to the direction G perpendicular to the cloth feeding direction.
As shown in FIG. 2, the separation plate 11 fixed to the bottom surface of the support plate 44 is disposed above the needle plate 14 between the upper roller 7 and the lower roller 3. The separation plate 11 is bent so that the tip of the separation plate 11 is lifted from the needle plate 14 when attached to the needle plate 14. Further, the separating plate 11 extends to the upstream side in the distribution feed direction from the rollers 3 and 7. That is, the separation plate 11 can partition the space above the needle plate 14 up and down, and the upper cloth CU is sent to the upper side of the separation plate 11 and the lower cloth CD is sent to the lower side.
Thus, the separation plate 11 is disposed between the two cloths CD and CU, and the lower cloth 3 is sandwiched between the lower roller 3 and the lower surface of the separation plate 11, and the upper roller 7 and the upper surface of the separation plate 11 are sandwiched. It is possible to sandwich the upper cloth CU.

(Cloth sensor)
As shown in FIGS. 4 and 5, the lower and upper cloth sensors 80 and 90 are arranged at predetermined positions in order to keep the sewing allowance (the length from one side edge of the cloth to the seam) constant during sewing. And for detecting the passage of the end portions of the upper cloth CU and the lower cloth CD in the cloth feeding direction. The cloth sensors 80 and 90 are provided close to the downstream side in the cloth feeding direction with respect to the lower roller 3 and the upper roller 7 (FIG. 2). These cloth sensors 80 and 90 are held by a common sensor base 41, are arranged horizontally, and are opposed to each other with a reflection plate 46 having both surfaces as reflection surfaces. Each of the cloth sensors 80, 90 includes a cloth presence sensor 81, 91 on the front side and a cloth edge sensor 82, 92 on the back side.

The sensor base 41 is formed in a substantially U shape when viewed from the cloth feeding direction F, and the above-described reflecting plate 46 is held horizontally inside the sensor base 41. The cloth moving direction by the rollers 3 and 7 (hereinafter, the cloth moving direction by the upper and lower rollers 3 and 7 is referred to as the adjustment direction G, and the cloth feeding direction is provided on the inner lower surface and the inner upper surface of the U-shaped portion. In the right direction (left side in FIG. 4) is the forward direction and the left hand direction (right direction in FIG. 4 is the reverse direction). Recesses 41a and 41b are formed. The reflecting plate 46 is disposed at a position slightly higher than the upper surface of the needle plate 14 so as to be inserted between the lower fabric CD and the upper fabric CU that are conveyed while being stacked on the needle plate 14. .
Accordingly, the lower cloth CD passes inside the U-shaped portion of the sensor base 41 and between the reflecting plate 46 and the lower concave portion 41a, and the upper cloth CU is inside the U-shaped portion of the sensor base 41. Thus, it passes between the reflector 46 and the upper concave portion 41b.

Each recess 41a, 41b is formed in a V shape when viewed from the adjustment direction G.
On the two inclined surfaces of the lower concave portion 41a, a cloth presence / absence sensor 81 including a light emitting sensor 83 and a light receiving sensor 84 is provided on the front side (near the opposite direction of the adjustment direction G). In addition, on the two inclined surfaces of the upper concave portion 41a, a cloth presence / absence sensor 91 including a light emitting sensor 93 and a light receiving sensor 94 is provided on the front side (near the opposite direction of the adjustment direction G).
The cloth presence sensor 91 on the upper wall surface is an upper cloth detecting means for detecting the end portion in the cloth feeding direction of the upper cloth CU, and the cloth presence sensor 81 on the lower wall surface detects the end portion in the cloth feeding direction of the lower cloth CD. It is a lower cloth detection means.
On the two inclined surfaces of the lower concave portions 41a and 41b, a cloth end sensor 82 including a light emitting sensor 85 and a light receiving sensor 86 is provided on the back side (near the opposite direction of the adjustment direction G). In addition, on the two inclined surfaces of the upper concave portions 41a and 41b, a cloth end sensor 92 including a light emitting sensor 95 and a light receiving sensor 96 is provided on the back side (near the opposite direction of the adjustment direction G).
The cloth edge sensor 92 on the upper wall surface (41b side) is a sensor that detects whether or not the side edge of the upper cloth CU is in a predetermined position, and the cloth edge sensor 82 on the lower wall surface (41a side) is the lower cloth. This is a sensor that detects whether or not the side edge of the CD is at a predetermined position.
The reflection plate 46 reflects the light emitted from each of the light emitting sensors 83, 85, 93, and 95. If there is no cloth edge on the optical path, the light reflected by the reflection plate 46 has high intensity and each Light is received by the light receiving sensors 84, 86, 94, 96.

  With the above structure, the upper cloth CU can enter between the reflecting plate 46 and the cloth presence sensor 91 and the cloth end sensor 92 on the upper wall surface, and the lower cloth CD can be inserted between the reflecting plate 46 and the cloth presence sensor 81 on the lower wall surface. It is possible to enter between the cloth edge sensor 82. If the cloth has entered, the cloth blocks the light from the light emitting sensors 83, 85, 93, and 95 and is not reflected by the reflecting plate 46, so that the light receiving sensors 84, 86, 94, and 96 detect the light. I can't. Using this principle, the presence / absence of the cloth and the side edge of the cloth are detected.

(Control device)
As shown in FIG. 6, the control device 13 includes a CPU 51 that performs various arithmetic processes, a ROM 52 that stores a program related to the drive control of each configuration described above, and a RAM 53 that stores various data related to the processing of the CPU 51 in a work area. And an EEPROM 54 as a storage unit for recording various setting data, accumulated data, and the like.
The control device 13 includes a sewing machine motor 20 for moving the sewing needle up and down, pulse motors 4 and 8, and solenoids 6 and 10 via drive circuits 20a, 4a, 8a, 6a and 10a, respectively. Connected.
In addition, a lower cloth sensor 80 and an upper cloth sensor 90 are connected to the control device 13 via interfaces 80a and 90a, respectively.
An unillustrated sewing machine main shaft (not shown) that is rotationally driven by the sewing machine motor 20 is provided with an encoder 24 that detects the shaft angle, and outputs the detected shaft angle to the control device 13 via the interface 24a. .
Further, the vertical feed sewing machine 100 includes an operation panel 40 for inputting various settings and displaying various information, and the operation panel 40 is also connected to the control device 13 through an interface 40a. .

  The ROM 52 of the control device 13 obtains a feed control program for causing the CPU 51 to execute feed control for feeding the fabric while keeping the sewing margin constant at the time of sewing, and a shift in the feed direction at the end portion of the upper fabric and the lower fabric at the end of sewing. The end portion position calculation program for causing the CPU 51 to execute the end portion position calculating process, and the difference between the pressing forces of the upper cloth CU and the lower cloth CD for eliminating the deviation of the end portion from the data obtained by the sewing already performed. In addition, an adjustment control program for causing the CPU 51 to execute adjustment control for appropriately controlling the outputs of the solenoids 10 and 6 of the upper cloth feed adjustment mechanism 9 and the lower cloth feed adjustment mechanism 5 is mainly stored.

  From the operation panel 40, the presence / absence of execution of an end portion position calculation process for acquiring the amount of later-described issuance, initial pressing force of the solenoids 6 and 10 of the cloth feed adjustment mechanisms 5 and 9 (can be set individually up and down), Select whether to automatically adjust or fix the initial pressing force of each solenoid 6, 10; feed pitch (up / down common); two-sewing mode where upper and lower fabrics are sewn or only one fabric The setting input can be made for each of the setting of whether or not the single-sewing mode is performed, whether or not the end portion position calculation process is executed, and whether or not adjustment control is executed, and the setting data is stored in the EEPROM 54.

(Feed control)
When the CPU 51 executes the feed control program, when the cloth presence / absence sensors 81 and 91 in the lower and upper cloth sensors 80 and 90 detect the cloth, The cloth end is detected, the rotation direction and the rotation amount of each roller 3, 7 are determined based on the detection result, and each pulse motor 4, 8 is driven.

  Specifically, when the side edge of the lower cloth CD (upper cloth CU) is detected by the cloth end sensor 82 (92), the control device 13 uses the lower roller 3 (upper roller 7) to detect the lower cloth CD (upper cloth CU). The lower pulse motor 4 (upper pulse motor 8) is controlled to move the upper cloth CU) in the direction opposite to the adjustment direction G, and the side edge of the lower cloth CD (upper cloth CU) is controlled by the cloth edge sensor 82 (92). Is no longer detected, the lower pulse motor 4 (upper pulse motor 8) is controlled so that the lower roller 3 (upper roller 7) moves the lower cloth CD (upper cloth CU) in the positive direction in the adjustment direction G. .

(Terminal position calculation processing)
In the control device 13, the CPU 51 executes an end portion position calculation program, thereby executing end portion position calculation processing for obtaining a shift (feed amount) in the feeding direction at the end portions of the upper cloth and the lower cloth at the end of sewing. Hereinafter, this process will be described in detail.
The amount of the file is calculated from the difference between the total feed amounts of the upper cloth CU and the lower cloth CD from the start to the end of sewing. In the sewing machine 100, the feed pitch of each needle (meaning the feed amount per stitch by the feed dog 1 and the feed foot 2 of the cloth feed mechanism. The feed pitch is the upper cloth feed adjustment mechanism 9 and the lower feed adjustment mechanism. Can be arbitrarily selected step by step by a setting input from the operation panel 40. The approximate total feed amount can be calculated by (set feed pitch) × (number of stitches from the start to the end of sewing). However, with respect to the last feed stroke, since the feed for the set feed pitch is almost not performed, the accurate total feed amount cannot be obtained by the above simple calculation.

  Processing for determining the final stroke feed amount will be described. FIG. 7 is an explanatory diagram showing the relationship between the trajectory of the feed operation of the feed dog 1 and the rotation angle θ of the sewing machine main shaft (the phase of the vertical movement of the sewing needle), and FIG. 8 is a cumulative cloth with respect to continuous rotation of the sewing machine main shaft. It is the diagram which showed the change of feed amount. In FIG. 8, n is the number of stitches from the start of sewing, A is the main shaft angle when the end is detected for one fabric, a is the total feed amount at that time, and B is when the end is detected for the other fabric. The spindle angle, b, indicates the total feed amount at that time.

  The feed dog 1 is provided by combining a vertical reciprocation operation synchronized with the vertical movement of the sewing needle (same cycle as the rotation of the sewing machine main shaft) and a reciprocation operation in the cloth feed direction F. As a result, FIG. As shown in FIG. 1, the feed dog 1 performs an orbital motion while drawing an elliptical oval locus. The cutting edge passes above the needle plate 14 in a part of the upper part of the elliptical locus, and the cutting edge is in contact with the lower surface of the lower cloth CD in the section to feed the cloth. Therefore, as shown in FIG. 8, a substantially step-like change is shown in which the feed amount increases intermittently only in the section before and after the main shaft angle including 0 ° (top dead center) in each needle drop.

When the feed pitch by the feed dog 1 is constant, the spindle angle θs at which the feed dog 1 starts feeding the lower cloth CD and the spindle angle θe at which the feed dog 1 finishes feeding are always constant in the cloth feed operation of each needle. The position of the feed dog in the feed direction at each spindle angle is also constant. Therefore, by preparing the position of the feed dog 1 at each spindle angle in this section in the EEPROM 54 as a storage means as a table, the end portion of the lower cloth CD can be passed during the last feeding operation in sewing. By reading the detected spindle angle of the encoder 24 when detected by the cloth presence sensor 81, the position of the feed dog 1 at that moment can be specified. The movement amount of the feed dog 1 from the main shaft angle θs to the detected main shaft angle is the feed amount of the lower cloth CD by the feed dog 1 in the last stroke.
Note that the setting of the feed pitch of the sewing machine can be changed in stages by setting input from the operation panel 40 described above. For this reason, a data table indicating the position of the feed dog 1 for each spindle angle needs to be prepared for each set value of the feed pitch.
This data table corresponds to the feed amount by the cloth feed mechanism at an arbitrary spindle angle within a range from the spindle angle θs at which feeding is started to the spindle angle θe at which feeding is finished for each feed pitch that can be input by the operation panel. It is a table. That is, by referring to the table, it is possible to quickly obtain the feed amount corresponding to the detected spindle angle of the encoder 24 when the passage of the end portion of the lower cloth CD is detected by the cloth presence sensor 81. .

On the premise of the above, the CPU 51 determines the number of stitches from the start to the end (separate needle drop when the cloth presence sensor 81 detects passage of the end of the cloth as the final needle drop) during sewing. A cumulative count is made based on the output, and the spindle angle when the cloth presence sensor 81 detects the passage of the cloth end is stored.
Then, assuming that the count value of the number of stitches at this time is n, the set sewing pitch is Pi, and the position of the feed dog 1 at the main shaft angle when the cloth end passage indicated by the table is detected is Bt, the feed of the lower cloth CD The total amount Sd is
Sd = (n-1) * Pi + Bt
It becomes.
In the above description, only the relationship between the feed dog 1 and the lower cloth CD is illustrated. However, since the feed leg 2 and the upper cloth CU operate on the same principle, a table is similarly prepared for each feed pitch. Thus, the total feed amount of the upper cloth CU can also be calculated.

  Then, by subtracting the total amount of feeding of the lower cloth CD from the total amount of feeding of the upper cloth CU obtained by these processes (or vice versa), it is the misalignment that is the misalignment amount between the end portions of the upper cloth CU and the lower cloth CD. The amount can be calculated.

In this calculation of the amount of feeding, the above method calculates the total feed amount of the upper cloth CU and the lower cloth CD, but the present invention is not limited to this, and other techniques may be used.
For example, when the end of either the upper cloth CU or the lower cloth CD is detected first, only the cloth feed amount in the stroke is calculated for the cloth that has reached the end first, and the end is detected later. For the cloth, it is possible to calculate the amount of feeding by the number of extra stitches × the set feed pitch and the sum of the differences between the feed amounts of the final strokes.

The CPU 51 records the calculated amount of the above-mentioned isting in the EEPROM 54 at the end of sewing or after the end of sewing. That is, the EEPROM 54 functions as a “recording unit”.
The amount of this is a parameter required in the adjustment control for adjusting the setting of the difference between the pressing forces of the upper cloth CU and the lower cloth CD, which will be described below. The value of the difference in pressing force between the upper cloth CU and the lower cloth CD is also required. For this reason, as shown in FIG. 9, when the amount of the file is recorded in the EEPROM 54, at the same time, the difference in the pressing force of each cloth (the difference in the pressing force of the lower solenoid 6 with respect to the pressing force of the upper solenoid 10) is also determined. Record in association.
By executing the above processing, the CPU 51 functions as a “terminal position calculation unit”. As described above, the CPU 51 calculates the amount of deviation between the end portions of the upper fabric and the lower fabric based on the main shaft angle when the fabric end position is detected, and thus can accurately calculate the amount of deviation. . Further, since the CPU 51 calculates the amount of deviation between the upper and lower cloth end portions based on the cumulative number of stitches, the feed pitch, and the main shaft angle when the cloth end position is detected, more accurately. The amount of deviation can be calculated.

(Adjustment control)
When the CPU 51 executes the adjustment control program, the control device 13 executes the adjustment based on the data indicating the relationship between the amount of the shearing obtained so far and the pressure difference between the upper cloth CU and the lower cloth CD. In order to eliminate this, adjustment control for setting an appropriate pressing force for each solenoid 6, 10 is executed. Hereinafter, this process will be described in detail.

  When a pressing force is applied to the upper cloth CU and the lower cloth CD by the upper cloth feed adjusting mechanism 9 and the lower cloth feed adjusting mechanism 5, respectively, the upper cloth CU and the lower cloth CD are compressed and stretched in the feed direction, thereby affecting the amount of feeding. Will be affected. Therefore, for example, when the amount of the delay is generated so that the end portion of the upper cloth CU becomes longer, the amount of the delay is reduced by resetting the pressing force difference so as to further increase the pressing force of the lower cloth CD. If the amount of stress is reduced so that the end of the lower cloth CD is longer, the amount of stress is reduced by resetting the pressure difference to increase the pressing force of the upper cloth CU. It becomes possible to do.

In FIG. 10, the X-axis is the difference between the pressing forces of the upper cloth CU and the lower cloth CD, the Y-axis is the amount of the feeding, and the amount of feeding obtained by sewing and the pressing force of the upper and lower cloths CU and CD at that time are obtained. It is the diagram plotted according to the result. In the figure, the X axis is positive when the pressing force of the upper cloth CU is large, and the Y axis is positive when the end portion of the upper cloth CU is longer.
For example, assuming that the pressure of the upper solenoid 10 is xu1 and the pressure of the lower solenoid 6 is xd1, the difference between the upper and lower pressing forces is x1 = xu1−xd1> 0, and the amount of misfeed obtained when the sewing is finished with each pressing force is y1 (> 0) and the pressure value obtained when the upper solenoid 10 pressure is xu2 and the lower solenoid 6 pressure is xd2, and the pressure difference between the top and bottom is x2 = xu2−xd2 <0, and sewing is completed with each pressing force. When the data for two points of data with y2 (<0) is acquired, the CPU 51 obtains the slope a of y = ax + b, which is an approximate straight line (1) connecting these two points, and the y intercept b. Calculate the value.
In the next sewing, the point (x3 ′, y3 ′) on y = ax + b, which is the approximate straight line (1), is set as the target point. That is, y3 ′ = 0 and x3 ′ satisfying 0 = ax + b is calculated.
Then, the pressure of the upper solenoid 10 and the pressure of the lower solenoid 6 are reset so that the pressure difference x3 ′ is obtained, and the set value is recorded in the EEPROM 54. Then, when an instruction is input to execute the next sewing, the pressing force of each solenoid 10, 6 is controlled to become a new set value, and the sewing is executed.

In addition, when data for three points or more is acquired, for example, when the result of sewing with the pressure difference x3 ′ described above results in the point (x3, y3) shown in FIG. In (y3 ≠ 0), the CPU 51 sets y = ax + b which is a new approximate line (2) by the least square method for the three points (x1, y1), (x2, y2), and (x3, y3). The slope a and y intercept b are obtained and stored in the EEPROM 54.
In the next sewing, the point (x4 ′, y4 ′) on y = ax + b, which is the approximate straight line (2), is set as the target point (y4 ′ = 0), and x4 ′ satisfying 0 = ax + b is set. calculate.
Then, the pressure of the upper solenoid 10 and the pressure of the lower solenoid 6 are reset again so that the pressing force difference x4 ′ is obtained, and the set value is recorded in the EEPROM 54 (also referred to as a recording unit).

  As described above, the setting value of the pressing force of each solenoid can be set so as not to be automatically corrected by the operation panel 40. In that case, (1) only the set value of the upper solenoid 10 is fixed, (2) only the set value of the lower solenoid 6 is fixed, and (3) both the set values of the upper and lower solenoids 10 and 6 are not fixed. Can be set.

And when a new pressure difference xn is calculated by the above process,
In the case of setting (1), only the set value of the lower solenoid 6 is corrected so that the pressing force difference xn is obtained.
In the case of setting (2), only the set value of the upper solenoid 10 is corrected so that the pressing force difference xn is obtained.
In the case of setting (3), the set value of the upper solenoid 10 and the set value of the lower solenoid 6 are equal correction amounts (one is + Δx and the other is -Δx) so that the pressing force difference xn is obtained. Correction is performed as follows.

By performing the adjustment control as described above, the CPU 51 functions as an “adjustment control unit”.
As described above, the CPU 51 controls either one or both of the upper cloth feed adjusting mechanism and the lower cloth feed adjusting mechanism when performing control so as to generate a difference between the appropriate upper cloth and lower cloth pressing forces. Because it is selectable
Optimal control can be performed on various sewing products.

  When the sewing amount yn is greater than a predetermined threshold when sewing is performed and the solenoid pressure difference xn 'is greater than a predetermined threshold, an approximate straight line is calculated again and a new (xn + 1, yn + 1) Is obtained, and the pressing force of the solenoids 6 and 10 is reset, and when the amount of inertia yn is less than a predetermined threshold value, the pressure difference between the solenoids is not calculated without calculating a new approximate curve. It may be set so that the number of repetitions of calculation of the pressing force correction value is suppressed by setting to xn ′ and performing subsequent sewing.

(Various processing during sewing)
The overall processing at the time of sewing when executing the end portion position calculation processing and adjustment control will be described. FIG. 11 is a flowchart showing the overall processing.
First, the upper cloth CU and the lower cloth CD are set on the vertical feed sewing machine 100 (step S1), and when the start switch of the sewing start of the operation panel 40 is pressed (step S3), the CPU 51 reads the setting of the sewing mode. It is determined whether execution of the sheet stitching mode and the end portion position calculation process is set (step S5).

  When the single-sewing mode or the non-execution of the end position calculation process is set (step S5: NO), the process is skipped to step S13, and the two-sewing mode and the end position calculation process is executed. If it is set (step S5: YES), the upper cloth information acquisition flag for acquiring the total amount of feeding of the upper cloth CU is turned ON (step S7), and then the total amount of feeding of the lower cloth CD is acquired. The cloth information acquisition flag is turned on (step S9), and the pressing force calculation flag for calculating the appropriate pressing force of each solenoid 6, 10 is turned on (step S11).

Next, sewing is started (step S13). At this time, if an error occurs or a pause is input (step S15: YES), the pressing force calculation flag is cleared (step S17), and the sewing is finished (step S23).
On the other hand, if an error has not occurred or no pause input has been input (step S15: NO), the upper cloth / lower cloth information acquisition process in the end position calculation process is started, and the spindle rotational speed and the like are started. (Step S19).
Thereafter, it is determined whether or not the cloth presence / absence sensors 81 and 91 continue to detect at least one of the upper cloth CU and the lower cloth CD (step S21), and either the upper cloth CU or the lower cloth CD is determined. The process of steps S15 to S21 is repeatedly executed during detection. Further, when both the upper cloth CU and the lower cloth CD are not detected, the sewing is finished (step S23).

Next, it is determined whether or not the pressing force calculation flag is in an ON state (step S25).
If the pressing force calculation flag is ON, a process for calculating the amount of mischief in the end position calculation process is executed (step S27).
Next, an appropriate pressing force difference calculation process in the adjustment control is executed (step S29), and the pressing forces of the solenoids 6 and 10 are reset so as to obtain the calculated appropriate pressing force difference (step S31). ), The pressing force calculation flag is cleared, and the entire process is terminated (step S33).

Next, the upper cloth / lower cloth information acquisition process in step S19 will be described in detail. FIG. 12 is a flowchart showing a subroutine of upper cloth / lower cloth information acquisition processing.
In the upper cloth / lower cloth information acquisition process, first, the upper cloth presence / absence sensor 91 determines whether the upper cloth is not detected and the upper cloth information acquisition flag is ON, and if these are not satisfied (step S41: NO) ), The process is skipped until step S47.
If these conditions are satisfied (step S41: YES), it is assumed that passage of the sensor position at the end portion of the upper cloth is detected for the first time, and the total number of stitches, the sewing pitch, and the spindle angle at that time are recorded ( Step S43). Then, the upper cloth information acquisition flag is cleared (step S45).
Therefore, even when the upper cloth / lower cloth information acquisition process is repeated by the above-described clear process and the repetition routine of steps S15 to S21, the determination of next step S41 is NO.

Next, the cloth presence / absence sensor 81 of the lower cloth determines whether the lower cloth is not detected and the lower cloth information acquisition flag is ON. If these are not satisfied (step S47: NO), the upper cloth / lower cloth information is determined. The acquisition process ends.
If these conditions are satisfied (step S47: YES), it is assumed that the passage of the sensor position at the end of the lower cloth is detected for the first time, and the total number of stitches, sewing pitch, and spindle angle at that time are recorded ( Step S49). Then, the lower cloth information acquisition flag is cleared (step S51).
Also in this case, even when the upper cloth / lower cloth information acquisition process is repeated by the clearing process of the above-described steps S15 to S21, the determination in the next step S47 is NO.

  By the above-described upper cloth / lower cloth information acquisition process, the total number of stitches, the sewing pitch, and the main shaft angle when the end portion of the upper cloth CU passes the cloth presence / absence sensor 91 and the end portion of the lower cloth CD are the cloth presence / absence sensor 81. The total number of stitches, the sewing pitch, and the spindle angle at the time of passing are acquired.

Next, the amount calculation process of step S27 mentioned above is demonstrated in detail. FIG. 13 is a flowchart showing a subroutine of the amount calculation process.
First, the CPU 51 calculates the total feed amount of the upper cloth CU from the number of stitches when sewing the upper cloth CU stored in the RAM 53, the sewing pitch, and the spindle angle of the sampling stroke (step S61).
Next, the CPU 51 calculates the total feed amount of the lower cloth CD from the number of stitches when sewing the lower cloth CD stored in the RAM 53, the sewing pitch, and the spindle angle of the sampling stroke (step S63).
Then, the amount of feeding is calculated by subtracting the total amount of feeding of the lower cloth CD from the total amount of feeding of the upper cloth CU (step S65).
Further, the set pressing force of the solenoids 6 and 10 at the time of sewing in which the amount of the above-mentioned misalignment is read is read, and the setting pressing force of the lower solenoid 6 is subtracted from the setting pressing force of the upper solenoid 10 to calculate the pressing force difference. (Step S67).
Then, the calculated amount of bias and the pressure difference are recorded in the EEPROM 54 in association with each other (step S69).
Thereby, the amount calculation process is completed.

Next, the appropriate pressing force difference calculation process in step S29 described above will be described in detail. FIG. 14 is a flowchart showing a subroutine of the appropriate pressing force difference calculation process.
First, the CPU 51 determines whether or not two or more sewing amount and pressing force difference data are stored in the storage area of the EEPROM 54 (step S71). If only one or less is stored, the process ends. To do.

Further, when data of two or more miscellaneous amounts and pressure difference are stored, the above-described approximate straight line y = ax + b is calculated. When there are two data, an approximate line is obtained from a straight line connecting two points, and when there are three or more data, an approximate line is calculated by the least square method.
That is, the y-intercept b is obtained from the approximate straight line (step S73), and the slope a of the straight line is calculated (step S75).
Further, the value of the pressing force difference at which the amount of the delay becomes 0 is specified from the approximate line (step S77). That is, when the value of the pressing force difference is G, calculation is performed using G = (0−b) / a.
Thereby, the appropriate pressure difference calculation process is completed.

Next, the pressing force difference setting process in step S31 described above will be described in detail. FIG. 15 is a flowchart showing a subroutine of the pressing force difference setting process.
First, the CPU 51 determines whether the value of the appropriate pressure difference obtained by the above-described appropriate pressure difference calculation process is within a limit value range that can be set (step S81). Since the set pressing force for each of the upper and lower solenoids 10 and 6 is in the range of 0 to 200, the limit value of the pressing force difference is 200.
If the calculated appropriate pressing force difference exceeds the limit (step S81: NO), the process ends without setting a new pressing force. The numerical value 100 of the set pressing force is set so as to be a reference of the pressing force 200 g.

In addition, when the appropriate pressing force difference is within the limit range ± 200 (the difference is between the upper side and the lower side, the sign is ±) (step S81: YES), the correction value H of the pressing force is calculated (step S81). S83). The correction value H of the pressing force is a value obtained by subtracting the current pressing force difference (the set pressing force of the upper solenoid 10 minus the setting pressing force of the lower solenoid 6) from the appropriate pressing force difference G.
Next, the CPU 51 reads the setting information indicating whether or not the setting change of the pressing force of each solenoid 6, 10 is possible, and determines whether both the solenoids 6, 10 can be changed (step S85).
If both the solenoids 6 and 10 can be set and changed, the correction value H / 2 is added to the current set pressing force of the upper solenoid 10 (step S87), and the lower solenoid 6 is set. The correction value H / 2 is subtracted from the current set pressing force (step S89).

On the other hand, if both the solenoids 6 and 10 are not changeable (step S85: NO), it is further determined whether only the upper solenoid 10 can be changed (step S91), and only the upper solenoid 10 is set. If it can be changed (step S91: YES), the correction value H is added to the current set pressing force of the upper solenoid 10 (step S93).
As a result of determining whether or not the setting change is possible only for the upper solenoid 10, if the setting change is not possible for the upper solenoid 10 (step S 91: NO), the current set pressing force of the lower solenoid 6 is not affected. The correction value H is subtracted (step S95).

As a result of changing the setting of the pressing force for either one or both of the solenoids 6 and 10, it is determined whether or not each setting pressing force is within the limit range (0 to 200) in the setting (step S97) and exceeds it. In such a case, the setting pressure is not changed for the exceeding solenoid, and the set pressing force is updated within the limit range.
Also, the set value data of the pressing force for each solenoid 6, 10 is transmitted to the operation panel 40 (step S99).
Thus, the pressing force difference setting process is completed.

(Effect of embodiment)
As described above, the vertical feed sewing machine 100 shows the mutual correspondence relationship when the record data of the amount of misfeed by the past two or more sewings and the difference between the pressing forces of the upper cloth CU and the lower cloth CD are obtained. It is possible to obtain an approximate straight line, and thereby obtain a pressure difference between the upper cloth CU and the lower cloth CD where the amount of stress is 0 by calculation. Therefore, since the appropriate amount of pressing force difference between the upper cloth CU and the lower cloth CD is specified by the actual amount of the overlap between the upper cloth CU and the lower cloth CD, any one of the cloths is stretched or shrunk or slipped. However, it is possible to eliminate the influence thereof, and it is possible to perform high-quality sewing with less occurrence of deviation.

Further, the control device 13 causes the CPU 51 functioning as an adjustment control unit to calculate an approximate straight line indicating a correspondence relationship between the amount of displacement and the pressing force difference by the least square method, and to calculate the appropriate pressing force of the upper cloth CU and the lower cloth CD. Since the difference is calculated, it is possible to obtain an appropriate pressing force difference even when a record of the amount of deviation due to three or more sewings and the pressing force difference between the upper cloth CU and the lower cloth CD is acquired.
Whenever a record of the amount of deviation due to new sewing and the difference in pressing force between the upper cloth CU and the lower cloth CD is acquired, a more appropriate difference in pressing force can be obtained. It becomes possible to further improve the sewing quality.

(Other)
In the above-described embodiment, the vertical feed sewing machine 100 has been exemplified. However, a sewing machine that is not a vertical feed, for example, a sewing machine equipped with a cloth feed mechanism that includes a normal cloth presser and a feed dog that can be pressed from above may be used. .

DESCRIPTION OF SYMBOLS 1 Feed dog 2 Feeding foot 3 Lower roller 4 Lower pulse motor 5 Lower cloth feed adjustment mechanism 6 Lower solenoid 7 Upper roller 8 Upper pulse motor 9 Upper cloth feed adjustment mechanism 10 Upper solenoid 13 Controller 51 CPU (terminal position) (Calculation unit, adjustment control unit)
54 EEPROM (Recording part)
80 Lower cloth sensor 81 Cloth presence / absence sensor (lower detection means)
82 cloth edge sensor 90 upper cloth sensor 91 cloth presence sensor (upper detection means)
92 Cloth edge sensor 100 Vertical feed sewing machine CD Lower cloth CU Upper cloth

Claims (5)

A cloth feeding mechanism for feeding the upper cloth and the lower cloth in a predetermined feeding direction;
An upper cloth detecting means for detecting an end portion of the upper cloth sent by the cloth feeding mechanism;
A lower cloth detecting means for detecting an end portion of the lower cloth sent by the cloth feeding mechanism;
An upper cloth feed adjusting mechanism that applies a pressing force only to the upper cloth for the feed operation by the cloth feed mechanism;
In a sewing machine comprising a lower cloth feed adjusting mechanism that applies a pressing force only to the lower cloth for the feed operation by the cloth feed mechanism,
An end portion position calculating unit that calculates a shift amount between the end portions of the upper cloth and the lower cloth based on the feed amount of the cloth feed mechanism and the detection timing of the upper cloth detecting means and the lower cloth detecting means;
A recording unit that records the amount of deviation and the difference in pressing force between the upper cloth and the lower cloth when the deviation occurs; and
The appropriate difference between the pressing force of the upper cloth and the lower cloth is obtained from the record of the deviation amount and the difference between the pressing forces of the upper cloth and the lower cloth due to two or more sewings of the recording portion, and the appropriate difference is obtained during the subsequent sewing. A sewing machine comprising: an adjustment control unit that controls the upper cloth feed adjusting mechanism or the lower cloth feed adjusting mechanism so as to cause a difference in pressing force between the upper cloth and the lower cloth.   The adjustment control unit, when there are three or more records of the amount of deviation due to sewing and the difference in pressing force between the upper and lower cloths, the difference between the amount of deviation and the pressing force between the upper and lower cloths by the least square method. The sewing machine according to claim 1, wherein a difference in pressing force between an appropriate upper cloth and a lower cloth is calculated based on the corresponding relation.   The end position calculation unit calculates a deviation amount between the end portions of the upper cloth and the lower cloth based on a main shaft angle when the respective end positions of the upper cloth and the lower cloth are detected. The sewing machine according to 1 or 2. An operation panel for inputting the feed pitch,
4. The sewing machine according to claim 3, further comprising a data table that associates the spindle angle with the feed amount of the cloth feed mechanism for each feed pitch that can be input by the operation panel.   When the adjustment control unit performs control so as to generate a difference in pressing force between the appropriate upper cloth and lower cloth, the upper cloth feed adjustment mechanism, the lower cloth feed adjustment mechanism, or both are controlled. The sewing machine according to any one of claims 1 to 4, wherein the sewing machine is selectable.

Images