JP4783529B2 - Sewing machine needle swing device - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a needle swing device such as a hole sewing machine or a staggered sewing machine.
[0002]
[Prior art]
Conventionally, as a needle swing device, a needle bar swinging base that supports a needle bar so as to be slidable in the axial direction thereof, a swinging means that swings the needle bar together with the needle bar swinging base, and one end of which is a drive source It is conceivable to have a crank rod that moves circularly in a vertical plane with the main axis as a normal line by the driving force from the main shaft and that has the other end interlocked with the sliding of the needle bar. With such a configuration, the needle bar swings in the vertical plane together with the needle bar swing base. The needle bar is linked to the crank rod and is supported by the needle bar swinging base so as to be slidable in the axial direction. For this reason, when one end of the crank rod moves circularly in the vertical plane by the drive source, the needle bar slides in the axial direction on the needle bar rocking base. Accordingly, the needle drop point is swung left and right along the vertical plane while the needle bar is moved up and down, and sewing such as staggered stitching and hole stitching can be executed.
[0003]
However, in the conventional needle swinging device as described above, the needle bar height at the timing when the hook sword tip captures the needle thread loop varies depending on the needle bar swinging position, and the needle thread trapping occurs due to the difference in the needle tip height. The distance between the tip of the hook and the threading hole of the needle differed greatly. Accordingly, the timing at which the hook sword tip captures the upper thread loop at each needle bar swinging position is different, and uniform seams cannot be formed at each position.
[0004]
Therefore, for example, as disclosed in Japanese Patent Publication No. 1-4422 by the present applicant, the connecting portion supported by the sewing machine frame and rotatably supported by the crank rod is reciprocated along one vertical fixed axis. It has been considered to provide guide means for slidably guiding.
[0005]
For example, FIG. 5 is a perspective view schematically showing an example of a drive system such as a conventional industrial sewing keyhole sewing machine. In the figure, the conventional known example will be described with details omitted. Reference numeral 7 denotes an upper shaft (main shaft) of the sewing machine, which is driven to rotate in a direction indicated by an arrow K via a pulley P by a motor (not shown). A counterweight 6 is fixed to the tip of the upper shaft 7, and the balance 5 and the crank rod 3 are rotatably connected to the counterweight 6, and the needle bar crank 16 is pivoted by a support screw 18. It is worn. Reference numeral 21 denotes an auxiliary rod (guided member) supported on a sewing machine frame (sewing machine head) (not shown) so as to be slidable in the vertical direction vertically. 6. Vertical reciprocating motion is performed through the crank rod 3 and the like. On the other hand, 9 is a needle bar connected so that the up-and-down reciprocating motion is transmitted to the opposing position of the crank rod 3 via the auxiliary bar 21. Reference numeral 100 denotes a needle bar oscillating base that reciprocally oscillates around a fulcrum pin 17 fixed to a machine frame (head, not shown) of the sewing machine in the direction indicated by arrows BC. The needle bar 9 holding the needle 11 is supported by the needle bar rocking base 100 so as to be slidable in the vertical direction, and the driving force in the sliding direction from the driving source is transmitted by the movement of the crank rod 3. The On the other hand, the reciprocating motion of the needle bar swinging table 100 swings the needle bar swinging rod 12 through the swing cam CM driven through the upper shaft 7 and the needle bar swinging two-rod R and the needle. The swinging motion is transmitted to the lower part of the bar swinging table 100. S (see FIG. 6) is a lower shaft that is disposed directly below the main shaft 7 and has a sewing machine hook. Thus, the swing fulcrum 17, the main shaft 7 and the lower shaft S are in the same vertical plane, and the guide means 21 is offset (L6).
[0006]
[Problems to be solved by the invention]
However, in the conventional needle swinging device having the arrangement as described above, the trajectory from the top dead center to the bottom dead center of the needle bar 9 and the bottom dead center to the top dead center as shown in FIG. The trajectory is determined and a difference occurs in the rotational angle (for example, φ <θ) of the counterweight 6 and the main shaft 7 that drives the needle bar 9, and the change in the rotational torque of the main shaft 7 is large between the operations that form both trajectories. Thus, there has been a problem that the movement speed of the needle bar 9 becomes unstable.
[0007]
Therefore, the present invention aims to reduce the fluctuation of the spindle torque during the movement cycle of the needle bar 9 and further stabilize the movement speed of the needle bar 9 to suppress the generation of noise and vibration when the sewing machine is operating. And
[0008]
[Means for Solving the Problems]
In order to achieve the above object, the needle swing device of the sewing machine according to claim 1, wherein the swinging arm supported rotatably on the sewing machine frame and the upper part of the sewing machine can be rotated around the fulcrum pin on the sewing machine frame. A needle bar swinging base supported at the bottom and connected to the swinging arm, a needle bar having a needle at the tip supported by the needle bar swinging base, and a needle bar pivotally supported by the needle bar. Rod, a crank rod that moves up and down in conjunction with the main shaft of the sewing machine, a connecting member that connects the crank rod and the rod so as to be rotatable at the connecting portion, and guides the connecting portion so that it can reciprocate along a predetermined path. In a needle swinging device comprising a guide member comprising a guide member and a guided member arranged so that the extension line of the guide path intersects the extension line of the main shaft axis, The needle bar vertical movement line at the time does not intersect with the spindle axis extension line and the spindle axis direction It is characterized by a look et arranging a predetermined distance from the guide path of the connection part.
[0009]
In order to achieve the above object, in addition to the configuration of the first aspect, the needle swing device of the sewing machine according to claim 2 is configured such that the swing fulcrum of the needle bar swing base is viewed from the axial direction of the main shaft. It is characterized by being in a vertical plane that is on the vertical movement line of the needle bar and parallel to the main spindle of the sewing machine.
[0010]
In order to achieve the above object, in addition to the structure of the first aspect, the needle swinging device for a sewing machine according to a third aspect is supported by the machine frame so as to be movable up and down, and the connecting member. Is fixed to the guided member.
[0011]
In order to achieve the above object, in addition to the structure of any one of claims 1 and 2, the needle swinging device for a sewing machine according to claim 4 is fixed to the machine frame or integrated with the machine frame. The guided member is loosely inserted so as to be movable along the guide surface.
[0012]
DETAILED DESCRIPTION OF THE INVENTION
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of an essential part of an embodiment of a needle bar swinging mechanism according to the present invention, and a drive mechanism on the right side of FIG. 5 is omitted. Moreover, the same code | symbol is attached | subjected to the structure same or equivalent to FIG. 5, and description is abbreviate | omitted.
[0013]
Here, reference numeral 1 denotes an auxiliary rod as a guided member of a guide means disposed on a vertical line orthogonal to an axis extension line of a machine upper shaft (main shaft) 7 on a machine frame (machine head) (not shown). The auxiliary rod 1 is supported so as to be slidable in the axial direction. A connecting member 4 is fixed to an intermediate portion of the auxiliary rod 1, and support shafts 4 a and 4 b are projected on the side surface in a direction perpendicular to the axis of the auxiliary rod 1 and in the direction of the main shaft 7. One end of the crank rod 3 is pivotally attached to one support shaft 4a, and the driving force is transmitted by the crank motion via the counterweight 6, the needle bar crank 16, the crank rod 3 and the like by driving the upper shaft 7 and connected. The member 4 and the auxiliary rod 1 are reciprocated up and down according to a guide of a sewing machine frame (not shown). The movement path (guide path) of the connecting portion of the rod 2 and the crank rod 3 is determined by the guidance of the sewing machine frame. On the other hand, the rod 2 is pivotally attached to the other support shaft 4b, and the other end of the rod 2 is configured to support the needle bar holder 8. Reference numeral 19 denotes a fixing screw for fixing the needle bar 9 to the needle bar holder 8. Reference numeral 10 denotes a needle bar vertical movement line when the needle bar 9 supported so as to be reciprocally slidable in the vertical direction is positioned outside the plane including the auxiliary bar 1 and parallel to the sewing machine upper shaft 7. This is a needle bar swinging base provided so as to be swingable. The needle bar swinging base 10 reciprocally swings around a fulcrum pin 17 fixed to the machine frame of the sewing machine in the direction indicated by arrows BC. The needle bar 9 is supported by the needle bar rocking base 10, and is driven by the crank rod 3, the connecting member 4, the rod 2 and the like through the needle bar holder 8. On the other hand, in the reciprocating motion of the needle bar swing base 10, the needle bar swing rod 12 is swung in the rotating direction, and the swing is attached to the swing arm 13 and the pin 14 and the pin 14 fixed thereto. It is configured to be transmitted via a square piece 15 that is rotatably engaged with the lower part of the needle bar swinging base 10.
[0014]
FIG. 2 is a configuration diagram of the main part when FIG. 1 is viewed from the direction of the arrow A in the figure. In this embodiment, the needle bar vertical movement line when the needle bar 9 is swung is the sewing machine main shaft 7 and the auxiliary bar. 1 and is provided perpendicular to the right side of the plane of the plane parallel to and perpendicular to the main spindle 7 of the sewing machine. Here, the auxiliary rod 1 as a guided member for guiding the lower end of the crank rod 3, that is, the movement locus of the connecting portion 4, is disposed in the vertical plane including the main shaft 7. Further, the needle bar vertical movement line is arranged from the auxiliary bar 1 at the same distance L6 as in the prior art. However, the amount of needle swing on the needle plate NP in FIG.
[0015]
3 is also a main part configuration diagram when FIG. 1 is viewed from the direction of arrow A in the figure, and is a main part configuration diagram of the needle swinging device having the configuration of FIG. Here, FIG. 2 shows the hook timing at which the hook sword tip and the needle 11 meet. Thus, in this embodiment, the main shaft 7 and the auxiliary rod 1 as the guided member are in the same plane, and the needle bar vertical movement line of the needle bar 9 and the lower shaft S include the main shaft 7 and the auxiliary rod 1. It is in the same plane offset from the plane.
[0016]
When the needle swinging device according to the present embodiment is operated, the same operation and effect as in the prior art can be obtained. In addition, the spindle rotation angle is from the top dead center to the bottom dead center and from the bottom dead center to the needle bar 9. As shown in FIG. 2, each of the top dead center paths is 180 °, so that fluctuations in the spindle rotational torque can be reduced, the rotational speed can be stabilized, and noise and vibration can be suppressed.
[0017]
Further, as shown in FIG. 3, the distance between the auxiliary rod 1, that is, the guide path of the connecting portion 4 between the rod 2 and the crank rod 3 and the vertical axis is given by L6 which is the same as that of the prior art. Thus, the needle thread loop can be captured, and the hook timing (position where the needle hole of the needle meets the hook point) can be made substantially constant at the left and right swing positions when the needle is swung.
[0018]
In addition, as another embodiment of the guide member of the guide means and the guided member for determining the guide path of the connecting portion of the rod 2 and the crank rod 3, although not shown, the following forms are also conceivable. Here, for the sake of convenience, FIG. 1 is used for the description, the same reference numerals are used for the same configurations, and different configurations are not illustrated and are only described.
[0019]
In the above embodiment, the sewing machine frame (not shown in FIG. 1) is used as the guide member for the guide means. In this embodiment, the auxiliary rod 1 is used as the guide member for the guide means. In other words, the auxiliary rod 1 is configured to be fixed to a sewing machine frame (not shown) in one or both of the upper and lower portions. The crank rod 3 that transmits the drive of the main shaft 7 via the counterweight 6 is rotatably connected to a connecting member 4 that also serves as a guided member of the guide means via a support shaft 4a. Further, the auxiliary rod 1 is inserted into the connecting member 4 and is slidable. Here, the auxiliary rod 1 is fixed to a sewing machine frame (not shown) at an appropriate position and posture, and the auxiliary rod 1 is inserted into the connecting member 4 so that both are slidable. Further, a rod 2 is rotatably connected to a support shaft 4b protruding on the opposite side of the connecting member 4 with the auxiliary rod 1 interposed therebetween, and the other end is connected to the needle bar holder 8 rotatably. The rod 2 transmits a driving force to the needle bar 9 in the vertical direction when the main shaft 7 is driven. With this configuration, when the main shaft 7 is driven, the driving member is transmitted to the crank rod 3 through the counterweight 6 and the like, and is connected to one end of the crank rod 3 as in the above-described embodiment. 4 is slid up and down according to a predetermined guide path along the auxiliary rod 1. Therefore, the needle bar 9 can perform a predetermined movement through the rod 2 rotatably connected to the support shaft 4b of the connecting member 4.
[0020]
Further, as another embodiment of the guide member and the guided member, a form as shown in FIG. 3 can be considered. The crank rod 3 that transmits the drive of the main shaft 7 via the counterweight 6 is connected to one end of the rod 2 by a connecting member 4 so as to be rotatable. Further, the other end of the rod 2 is rotatably connected to a needle bar holder 8, and the needle bar 9 is swung in the vertical direction when the main shaft 7 is driven. Reference numeral 41 denotes a follower piece as a guided member rotatably provided at one end of the connecting member 4. The follower 41 is loosely inserted between guide grooves 1a serving as guide means including a pair of guide surfaces so as to be fixed to a sewing machine frame (not shown) so as to be slidable in the groove forming direction. . When the main shaft 7 is driven, the movement locus (guide path) of the other end of the crank rod 3 rotating at one end with the rotation of the main shaft 7 (the connecting portion with the rod 2) is swung along the direction in which the guide groove 1a is formed. Can be made. Accordingly, the driving force is transmitted to the rod 2 together with the other end of the crank rod 3 that performs a predetermined swinging motion by the guide groove 1a, and the needle bar 9 can perform the predetermined motion.
[0021]
Thus, the guide method of the connecting part of the rod and the crank rod by the guide means including the guide member and the guided member is not limited, and various methods can be considered.
[0022]
The auxiliary rod 1 and the guide groove 1A may be provided so that the posture can be adjusted, or may be fixed as a fixed posture. If the posture can be adjusted, it is possible to appropriately set the offset amount of the guide path by the guide means from the vertical movement line of the needle bar, the inclination of the guide path, etc., and perform the desired needle bar movement. Will be able to.
[0023]
It should be noted that the present invention is not limited to the above-described embodiment, and various forms can be considered without departing from the technical scope of the present invention.
[0024]
For example, in this embodiment, the description has been made with the guide means (auxiliary bar 1) having a vertical guide path of the connecting portion. However, the guide path does not have to be vertical, and passes through a straight line that intersects with the axial extension line of the sewing machine main shaft. As long as it is arranged in the above-mentioned manner, an appropriate arrangement may be made without departing from the technical scope of the present invention, such as making an appropriate angle in the main shaft axis direction or the main shaft circumferential direction.
[0025]
In the present embodiment, the description is based on the configuration in which the rocking fulcrum of the needle bar and the rocking fulcrum of the needle bar rocking table are coincident, but the present invention is not limited to this mode. However, it is preferable that the fulcrum fulcrum of the needle bar oscillating base is in a plane including the needle bar vertical movement line and parallel to the sewing machine main shaft.
[0026]
【The invention's effect】
As described above, according to the present invention, the following effects can be obtained.
[0027]
By setting the guide means the distance from the vertical movement line of the needle bar to approximately the same as the conventional, the timing of the contact between the needle and the hook point is the same as the conventional, maintaining the performance that can form a uniform seam, By offsetting the needle bar vertical movement line by a predetermined distance from the guide means without crossing the axis extension line of the needle bar, the needle bar top dead center from the needle bar top dead center to the needle bar bottom dead center It is possible to make the spindle rotation angle in the operation process at the same time equal. As a result, fluctuations in the spindle torque during the movement of the needle bar can be reduced, the movement speed of the needle bar can be stabilized, and the generation of noise and vibration during sewing machine operation can be suppressed.
[0028]
In addition, since the needle bar rocking fulcrum is arranged in a plane that includes the needle bar vertical movement line and is parallel to the upper shaft, there is almost no vertical movement of the needle bar bearing due to rocking. Interference between the needle bar hug and the needle bar bearing can be prevented.
[Brief description of the drawings]
FIG. 1 is a perspective view of a main part of an embodiment of a needle bar swing mechanism according to the present invention.
2 is a main part configuration diagram showing a state of the needle bar top dead center and needle bar bottom dead center of the needle swing device of FIG. 1; FIG.
3 is a main part configuration diagram showing hook timing of the needle swinging device of FIG. 1; FIG.
FIG. 4 is an explanatory diagram of another embodiment of the present invention.
FIG. 5 is a perspective view schematically showing a drive system of a sewing machine provided with a conventional needle swing device.
6 is a main part configuration diagram showing a state at the time of needle bar upper dead center and needle bar lower dead center of the needle swing device of FIG. 5;
[Explanation of symbols]
1 Auxiliary bar (present invention) 1a Guide groove 21 Auxiliary bar (conventional example)
2 Rod 3 Crank rod 4 Connecting member (connecting part)
4a, 4b Connecting member support shaft 41 Follower piece 5 Balance 6 Balance weight 7 Upper shaft (main shaft)
8 Needle bar holding 9 Needle bar 10 Needle bar rocking base (present invention)
100 Needle bar rocking base (conventional example) 11 Needle 12 Needle bar rocking rod 13 Rocking arm 14 Pin 15 Square piece 16 Needle bar crank 17 Supporting pin 18 Support screw 19 Fixing screw CM Swing cam R Needle bar rocking 2 Rod P Pulley NP Needle plate

Claims (4)

A swinging arm supported rotatably on the sewing machine frame, a needle bar swinging base supported on the upper part of the sewing machine frame so as to be rotatable around a fulcrum pin, and connected to the swinging arm at the lower part; A needle bar which is supported by the needle bar swinging base so as to be movable up and down and has a needle at the tip; a rod which is rotatably supported by the needle bar; a crank rod which moves up and down in conjunction with the sewing machine main shaft; and a crank rod; A connecting member that rotatably connects the rod to the connecting portion, and guides the connecting portion so as to reciprocate along a predetermined path, and is arranged so that the extension line of the guide path intersects the extension line of the spindle axis. And a guide means comprising a guide member and a guided member provided, wherein the needle bar vertical movement line at the time of needle swing of the needle bar is zero and does not intersect with the spindle axis extension line. Arranged at a predetermined distance from the guide path of the connecting portion when viewed from the axial direction. Needle swing device of a sewing machine according to symptoms. 2. The needle swinging of the sewing machine according to claim 1, wherein a swing fulcrum of the needle bar swinging base is on a vertical movement line of the needle bar as viewed from the main shaft axis direction and is in a vertical plane parallel to the main shaft of the sewing machine. apparatus. The sewing machine needle swinging apparatus according to claim 1 or 2, wherein the guided member is supported by the machine frame so as to be movable up and down, and the connecting member is fixed to the guided member. The guide member comprises a pair of guide surfaces fixed to the machine frame or integrated with the machine frame, and the guided member is loosely inserted so as to be movable along the guide surface. 3. The sewing machine needle swing device according to any one of the above items.

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