JP2006141706A - Needle bar mechanism of twin needle sewing machine and twin needle sewing machine equipped with this - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To raise durability under an environment of drying which suppresses the employment of lubricating oil. <P>SOLUTION: A needle bar support body 40 which separately supports a pair of needle bars 20 in a way capable of up-and-down motion, a needle bar vertical movement mechanism 50 which moves each needle bar up and down using a needle bar connecting stud 51 held separately, a clutch mechanism 60 equipped with two or more input members 62 and 66 which receive input of holding and loosening of each needle bar, and a change member 81 which performs a change of holding and loosening of the needle bar by alternatively contacting each of the input members which perform rising and falling movements are included, and a grease feed means 91, which is prepared in the needle bar connecting stud and provides grease to the sliding part of the needle bar connecting stud and each of the needle bars, is included. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a needle bar mechanism that performs sewing using two needle bars simultaneously or selectively and a two-needle sewing machine including the needle bar mechanism.

  In the needle bar mechanism of a two-needle sewing machine having a one-needle stop function that can selectively stop the vertical movement of a pair of needle bars, the needle bar support that individually supports the pair of needle bars so as to be movable up and down A needle bar vertical movement mechanism that moves the needle bar up and down using a needle bar holder that individually holds the body and a pair of needle bars, and holds and releases each needle bar with respect to the needle bar holder, and each needle A clutch mechanism having a plurality of input members that receive an input of an operating force from the outside for switching between holding and releasing of the bar, and selectively contacting each of the input members by the lifting and lowering operation of the clutch mechanism. And a switching member that switches between holding and releasing (see, for example, Patent Document 1).

In the needle bar mechanism of the two-needle sewing machine, the two needle bars supported by the needle bar support are held on the needle bar holder by the clutch mechanism. The clutch mechanism includes an input member for bringing each needle bar into a holding state and an input member for putting the needle bar in a holding state into a released state, and each input member is given an external force. Causes the clutch mechanism to perform a holding or releasing operation.
By performing a switching operation, the switching member can be brought into contact with any of the input members when the needle bar is moved up and down, and any one of the input members receives an external force due to the contact. The needle bar is held or released.
JP-A-1-300990

By the way, the needle bar mechanism of the two-needle sewing machine is a mechanism that supports the needle bar, and is thus arranged on the surface of the sewing machine frame. And in the sewing machine surface part, in order to avoid generation | occurrence | production of the stain | pollution | contamination of a to-be-sewn thing, the dry-ization which suppresses use of lubricating oil is advanced.
On the other hand, the clutch mechanism includes a clutch member that is engaged with each needle bar, an input member that moves the clutch member in the engagement direction, a locking claw that restricts the movement of the clutch member in the engagement direction, and a restriction state of the locking claw Each of the clutch mechanism, the switching member, and each input member are made of carburized case-hardened steel, and each needle bar is held in a dry environment. Since the collision is repeated at the time of release, there is a problem that fretting wear is likely to occur.

  The object of the present invention is to improve the durability in a dry environment.

  The invention according to claim 1 is a needle that moves each needle bar up and down using a needle bar support that individually supports a pair of needle bars so as to be movable up and down, and a needle bar holding that individually holds the pair of needle bars. A clutch mechanism comprising a bar vertical movement mechanism and a plurality of input members for holding and releasing the needle bars with respect to the needle bar hug and receiving an input of an operating force from the outside for switching between holding and releasing the needle bars And a switching member that selectively makes contact with one of the input members by the lifting and lowering operation of the clutch mechanism and switches between holding and releasing of each needle bar, and selects the vertical movement of the pair of needle bars In a needle bar mechanism of a two-needle sewing machine having a one-needle stop function that can be stopped in a mechanical manner, a grease supply means that is provided on the needle bar holder and supplies grease to a sliding portion between the needle bar holder and each needle bar It has a configuration that comprises.

In the above configuration, at the time of sewing with two needles, the two needle bars supported by the needle bar support are held on the needle bar holder by the clutch mechanism.
When sewing is performed with only one of the needle bars, an operation is applied to the switching member so as to come into contact with the input member for releasing the holding state of the needle bar. As a result, the released needle bar is left behind, and only the needle bar holder and the held needle bar move up and down, causing sliding between the released needle bar and the needle bar holder. Become.
At this time, since the grease supply means provided in the needle bar holder supplies the grease to the sliding portion, smooth operation is performed.
It is desirable that an input member for releasing the holding state of the needle bar is provided for each needle bar. However, in order to change the holding state from the released state of the needle bar, the input member may be two needle bars for each needle bar. May be shared. The same applies to other configurations described below.

The invention according to claim 2 employs a configuration in which the grease supply means is an impregnation member that impregnates and holds the grease and is provided on the needle bar holder so as to be in sliding contact with each needle bar.
In the above-described configuration, the needle bar that has been released slides relative to the needle bar holder, and grease is supplied by the impregnating member that is in sliding contact with the sliding part.

  According to a third aspect of the present invention, there is provided a needle bar that vertically moves each needle bar using a needle bar support that individually supports a pair of needle bars so as to be movable up and down, and a needle bar holder that individually holds the pair of needle bars. And a clutch mechanism comprising a plurality of input members for holding and releasing each needle bar with respect to the needle bar holding and receiving an input of an operating force from the outside for switching between holding and releasing each needle bar. A switching member that selectively contacts one of the input members by the lifting and lowering operation of the clutch mechanism and switches between holding and releasing each needle bar, and selectively moves the pair of needle bars up and down. In the needle bar mechanism of a two-needle sewing machine having a one-needle stop function that can be stopped at the same time, a needle bar holder is provided with grease supply means for supplying grease to at least one of the clutch mechanism and the switching member, Small number of switching members Kutomo the contact site between the input member, the nitriding treatment is applied, chromium and high carbon alloy steels containing, adopts a configuration that.

The nitriding treatment may be any of gas soft nitriding, salt bath nitriding, or ion nitriding.
The high carbon alloy steel is iron containing carbon in a proportion of 0.7 to 2.1%, and may contain Al, W, V, Mo and the like.
Although not particularly limited, the chromium content is preferably 0.9 to 18 (please specify the upper limit value) percentage.

In the above configuration, at the time of sewing with two needles, the two needle bars supported by the needle bar support are held on the needle bar holder by the clutch mechanism.
When sewing is performed with only one of the needle bars, an operation is applied to the switching member so as to come into contact with the input member for releasing the holding state of the needle bar. As a result, the input member and the switching member come into contact with each other by the vertical movement of the needle bar holder, and the holding state of the other needle bar by the needle bar holder is released.
When sewing with two needle bars again, an operation is applied to the switching member so as to come into contact with the input member for holding the needle bar whose held state is released. As a result, the input member and the switching member come into contact with each other by the vertical movement of the needle bar holder, and the released needle bar is again held by the needle bar holder.
In this way, each time holding and releasing of the two needles are performed, the switching member has a high frequency of collision with each input member, but is a high carbon alloy steel having chromium nitride formed on the surface thereof. For this reason, the hardness is increased, and the corrosion resistance and wear resistance are improved.
Further, the grease supply means improves the corrosion resistance and wear resistance of at least one of the clutch mechanism and the switching member.

The invention described in claim 4 has the same configuration as that of the invention described in claim 1, and adopts a configuration in which a compound layer is formed by nitriding treatment of the switching member.
The compound layer formed by nitriding treatment is also called a white layer, and has a characteristic that it has high hardness but is brittle.
When such a white layer is interposed between the base material of the switching member and the input member at the time of a collision, the base material side of the switching member is protected, and the corrosion resistance and wear resistance are improved.
The thickness of the white layer is not particularly limited, but is preferably about 1 [μm] or more.

The invention according to claim 5 has the same configuration as that of the invention according to claim 3 or 4, and at least a contact portion of each input member with the switching member is a high carbon alloy steel subjected to fine particle shot treatment. , Is adopted.
When holding or releasing the two needles, any input member will collide with the switching member, but the surface is high carbon alloy steel, so the hardness is high, and by the fine particle shot treatment, Fatigue is less likely to occur due to repeated collisions. Further, when the lubricant is supplied even in a small amount, the lubricant is held in a minute recess formed by the fine particle shot, and fretting wear at the time of collision is also reduced.

Here, the fine particle shot process refers to a so-called WPC process (registered trademark). Such a fine particle shot process is a process of causing a fine particle ball having a smaller diameter to collide with a material at a higher speed than the shot bean process compared to a normal shot bean process. The fine particles used have a diameter of about 20 to 100 [μm]. When ceramic balls are used as the fine particle balls, it is desirable that the above-mentioned diameter range is close to a small range (near 20 [μm]). In the case of using, it is desirable that the above-mentioned diameter range is close to a large range (around 100 [μm]). The injection speed of the fine particles is preferably about 300 [m / s] or more, and the injection time is not particularly limited.
Further, although not particularly limited, as an example, the infinite number of concave portions formed by the fine particle shot processing has a maximum width (a size that allows the largest measurement of the concave portion, except for a size in the depth direction). Those within the range of 0.1 to 10.0 [μm], more preferably 1.0 to 2.0 [μm] preferably occupy the largest area ratio in the unit area, and more preferably the area ratio is 50 percent or more. desirable.

The invention according to claim 6 has the same configuration as that of the invention according to claim 3, 4 or 5, and the surface hardness of the contact portion with each input member of the switching member is set to be the switching member of each input member. It is configured to be higher than the abutting portion.
In the above configuration, since the switching member has a higher collision frequency than each input member, the switching member hardness is set higher than that of the input member at least for the collision portion, and the switching member is more wear resistant. To improve the durability balance.

  The invention according to claim 7 is a needle that moves each needle bar up and down using a needle bar support that individually supports a pair of needle bars so as to be movable up and down, and a needle bar holding that individually holds the pair of needle bars. And a clutch mechanism comprising a plurality of input members for holding and releasing each needle bar with respect to the needle bar holding and receiving an input of an operating force from the outside for switching between holding and releasing each needle bar. A switching member that selectively makes contact with any of the input members by the lifting and lowering operation of the clutch mechanism to switch between holding and releasing of each needle bar, and selectively moving the pair of needle bars up and down In the needle bar mechanism of the two-needle sewing machine having a one-needle stop function capable of stopping at the same time, a needle bar holder is provided with a clutch mechanism and a grease supply means for supplying grease to at least one of the switching members. Less input members Also contact portions between the switching member and the carburized hardened steel which has been subjected to fine particle shot process, adopts a configuration that.

Even in the above configuration, the switching of the holding release of the two needle bars is performed in the same manner as in the third aspect of the invention.
And when the two needles are held or released, any input member will collide with the switching member, but the surface is carburized case-hardened steel that has been subjected to fine particle shot treatment, so the hardness is high. , Fatigue due to repeated collisions is less likely to occur. Further, when the lubricant is supplied even in a small amount, the lubricant is held in a minute recess formed by the fine particle shot, and fretting wear at the time of collision is also reduced.
Further, the grease supply means improves the corrosion resistance and wear resistance of at least one of the clutch mechanism and the switching member.

According to an eighth aspect of the present invention, the needle bar mechanism of the two-needle sewing machine according to any one of the first to seventh aspects is provided inside the surface portion of the sewing machine frame, and the inside of the surface portion of the sewing machine frame is lubricated with grease. Is adopted.
In the said structure, grease is supplied to the needle bar mechanism as described in any one of Claims 1-5, and each sliding site | part can operate | move smoothly. In particular, since fretting wear is caused by minute sliding at the time of collision, grease further suppresses wear.
The term “drying” includes not only the use of liquid lubricants and the suppression of use, but also the use of lubricants such as grease with high viscosity.

According to the first aspect of the present invention, grease can be supplied to the sliding portion between the needle bar holder and the needle bar, and the needle bar holder can be smoothly moved up and down even when the holding of the needle bar is released. It becomes possible. Therefore, it is possible to smoothly perform sewing in the sewing machine.
Further, since the grease supply means is provided on the needle bar holder, the grease supply is performed only when the relative movement occurs between the needle bar and the needle bar holder (when the holding of the needle bar is released). However, by supplying only when sliding occurs, the necessary minimum supply can be performed, and the grease consumption can be reduced.

  Since the grease supply means is an impregnating member that impregnates and holds the grease, the grease can be supplied only by sliding the member to the portion to be supplied, and the grease can be stored. It is not necessary to provide a route for moving to the supply site, and the structure can be simplified. Therefore, it is possible to improve the productivity of the needle bar mechanism.

  In the invention according to claim 3, since the collision part of the switching member that causes a collision at the time of switching between holding and releasing of each needle bar is formed of chrome-containing high carbon alloy steel subjected to nitriding treatment, the hardness is higher than the conventional one. As a result, the corrosion resistance and wear resistance are improved. Therefore, the change in these characteristics improves durability against fretting wear due to repeated collisions, and it is possible to maintain normal operation for a long period of time. Further, the grease supply means improves the corrosion resistance and wear resistance of at least one of the clutch mechanism and the switching member.

  In the invention according to claim 4, since the white layer having high hardness and brittle characteristics is formed at the collision part of the switching member, the white layer is the base material between the base material of the switching member and the input member at the time of collision. Protecting, even in a dry environment, durability against fretting wear is further improved, and normal operation can be maintained for a longer period of time.

  Since the invention according to claim 5 is a high carbon alloy steel subjected to fine particle shot treatment on the collision part of the input member that causes collision when switching between holding or releasing any one of the needle bars, As a result, fatigue resistance and wear resistance are improved. Therefore, these characteristics change improve durability against fretting wear caused by repeated collisions even in a dry environment with poor lubrication, and can maintain normal operation over a long period of time. It becomes.

  The invention according to claim 6 sets the hardness of the input member higher than that of at least the switching member having a higher collision frequency than each input member, and improves the switching member with respect to wear resistance. Thus, since the durability balance is made better, the overall durability of the mechanism is improved, and normal operation can be maintained for a longer period of time.

  Since the invention according to claim 7 is a carburized case-hardened steel subjected to a fine particle shot treatment on the collision part of the input member that causes a collision at the time of switching between holding or releasing one of the needle bars, This increases the fatigue resistance and wear resistance. Therefore, the change in these characteristics improves durability against fretting wear caused by repeated collisions, and it is possible to maintain normal operation for a long period of time. Further, the grease supply means improves the corrosion resistance and wear resistance of at least one of the clutch mechanism and the switching member.

According to the eighth aspect of the present invention, grease can be supplied to the needle bar mechanism according to any one of the first to seventh aspects, and each sliding portion can be operated smoothly. Therefore, it is possible to smoothly perform sewing in the sewing machine.
Furthermore, since fretting wear is caused by minute sliding at the time of collision, the grease further suppresses wear in the needle bar mechanism. Further, when a material subjected to fine particle shot processing is used, grease is held in the fine dimples formed by the processing, and a higher lubrication drop can be obtained.
Accordingly, it is possible to ensure a smooth sewing operation of the sewing machine in a dry environment.

(Overall configuration of the embodiment of the invention)
Hereinafter, embodiments of the present invention will be described in detail with reference to FIGS.
1 is a front view of a needle bar mechanism 10 of a two-needle sewing machine according to an embodiment of the present invention, FIG. 2 (A) is a side view with a part of the needle bar 20 omitted, FIG. 2 (B) is a front view, and FIG. These show the front view of the needle bar mechanism 10 when the needle bar is lowered.
The two-needle sewing machine includes a sewing machine frame that stores and holds each configuration for sewing inside, a sewing machine motor that is a vertical movement drive source of two sewing needles of a needle bar mechanism 10 described below, and a needle plate The hook mechanism or looper mechanism that catches the upper thread inserted into each sewing needle that moves up and down below and binds the lower thread, the thread tension mechanism that applies tension to the upper thread, and the vertical movement of the sewing needle In general, there are provided various general mechanisms necessary for sewing such as a balance mechanism for pulling up the upper thread in synchronization with the cutting mechanism and a cutting mechanism for cutting the upper thread or the lower thread. Since these mechanisms are the same as those well-known except for the needle bar mechanism 10, they are not shown or described in detail.

A needle bar mechanism 10 for a two-needle sewing machine is provided in a surface part that is the tip of an arm part (not shown) of the two-needle sewing machine, and a pair of needle bars 20 that individually hold two sewing needles (not shown). Are moved up or down simultaneously or selectively.
In the following description, the vertical vertical direction is the Z-axis direction, the longitudinal direction of the arm portion of the two-needle sewing machine in a state where it is installed on the horizontal plane is the Y-axis direction, parallel to the plate surface of the needle plate (not shown) and orthogonal to the Y-axis direction. The direction to perform is the X-axis direction. Note that the X-axis direction, the Y-axis direction, and the Z-axis direction are orthogonal to each other.

  A needle bar mechanism 10 of a two-needle sewing machine individually supports a pair of needle bars 20 each having a first engagement hole 21 and a second engagement hole 22 and each needle bar 20 so as to be movable up and down. A needle bar up-and-down moving mechanism 50 for moving each needle bar 20 up and down using a needle bar support frame 40 as a needle bar support to be used, and a needle bar holder 51 for holding a pair of needle bars 20 individually, and each needle bar The holding of each needle bar 20 by the needle bar holder 51 can be selectively switched between the holding state and the released state by using a pair of clutch members 61 for inserting and removing the tip from the first engagement hole 21 of the 20. The needle bar support frame 40 is held by using a clutch mechanism 60 and a stopper member 71 that inserts and removes the tip of the needle bar 20 from the second engagement hole 22 of which the holding state is released by the clutch mechanism 60. Stopper mechanism 70 and either needle bar 2 by an artificial input operation Is selected and the switching mechanism 80 for switching the holding state and the release state in the clutch mechanism 60, and the grease supply that is provided in the needle bar holder 51 and supplies grease to the sliding portion between the needle bar holder 51 and each needle bar 20 And an impregnating member 91 as a means.

(Needle bar)
Each needle bar 20 is supported by the needle bar support frame 40 in a state normally along the Z-axis direction, and when performing needle swinging, approximately the middle in the longitudinal direction of each needle bar 20 via the needle bar support frame 40. A rotational swing motion is applied about the axis along the Y-axis direction at the position. When such swinging is performed, the upper and lower ends of each needle bar 20 swing along the X-axis direction.

Each needle bar 20 is a rod-like body having a flat surface 23 formed on a part of the circumferential surface of a round bar having a circular cross section, as shown in the figure, and holds a sewing needle (not shown) at its lower end.
In a state where the needle bar 20 is supported along the Z-axis direction, the flat surface 23 is supported by the needle bar support frame 40 so as to be in a state along the YZ plane. A groove portion 24 is formed along the longitudinal direction at the intermediate position in the Z-axis direction on the flat surface 23.

Further, a first engagement hole 21 and a second engagement hole 22 are formed on the flat surface 23 in the vicinity of the lower end and the upper end of the groove 24 so as to overlap the groove 24. Has been.
The first engagement hole 21 is formed in a rectangular shape corresponding to the tip shape so that the tip portion of the clutch member 61 can be inserted. Such a rectangular shape corresponds to the front end portion of the clutch member 61 protruding in a substantially rectangular shape, and the length of the long side and the short side of the rectangle are the width of the front end portion of the substantially rectangular shape of the clutch member 61, respectively. It is set slightly larger than the vertical width.
The second engagement hole 22 is located above the first engagement hole 21 and has a rectangular shape in front view and half in side view corresponding to the shape of the tip of a stopper member 71 described later. It is formed in a circular shape.

An oscillating plate 25 is swingably attached to the inside of the groove portion 24 along the longitudinal direction of the groove portion 24. The swing plate 25 is supported by a support shaft along the Y-axis direction at an intermediate position between the first engagement hole 21 and the second engagement hole 22, and both ends thereof are X-axis by swinging. Move along the direction. That is, one end and the other end of the swing plate 25 move in the first engagement hole 21 and the second engagement hole 22 along the depth direction of the engagement holes 21 and 22, respectively. .
Further, when one end portion of the swing plate 25 is pushed into the vicinity of the deep portion of the first engagement hole 21, the other end portion is pushed out to the flat surface 23 in the second engagement hole 22, and the other end portion is pushed. When pushed into the vicinity of the deep portion of the second engagement hole 22, one end portion is formed into a shape that is pushed out to the flat surface 23 in the first engagement hole 21.
That is, for the same needle bar 20, when the clutch member 61 is inserted into the first engagement hole 21, the stopper member 71 that has already been inserted into the second engagement hole 22 is pushed out by the swing plate 25. When the clutch member 71 is inserted into the second engagement hole 22, the clutch member 61 that has already been inserted into the first engagement hole 21 is pushed out by the swing plate 25.

Further, when the needle bar 20 moves up and down, the needle bar 20 is engaged with the clutch mechanism 60 through the first engagement hole 21 and held by the needle bar holder 51. On the other hand, when the vertical movement is stopped for sewing with one needle, the clutch mechanism 60 is released and the second engagement hole 22 engages with the stopper mechanism 70 to hold the needle bar support frame 40.
As described above, each needle bar 20 is normally held by either the clutch mechanism 60 or the stopper mechanism 70.

(Needle bar support frame)
FIG. 4 is a cross-sectional view of the needle bar mechanism 10 along the center line of one needle bar and the XZ plane in the state of FIG. As shown in FIGS. 1 and 4, the needle bar support frame 40 is formed with insertion holes through which upper and lower needle bars 20 are inserted so that two needle bars 20 are arranged in the Y-axis direction. The rod 20 is supported so as to be movable up and down.
In the vicinity of the support portion of the needle bar 20 at the lower portion of the needle bar support frame 40, a supply member 41 such as a nonwoven fabric or urethane to which lubricating oil or grease is supplied is provided, and slides on the supply member 41. Each needle bar 20 is arranged as described above. Thereby, lubricating oil or grease is supplied to the sliding part of each needle bar 20 and the needle bar support frame 40, and the vertical movement is performed smoothly.

A stopper mechanism 70 is provided in the vicinity of the support portion of the needle bar 20 above the needle bar support frame 40, and a switching mechanism 80 is provided immediately below the stopper mechanism 70 of the needle bar support frame 40. Yes. The stopper mechanism 70 and the switching mechanism 80 will be described in detail later.
Further, in the vicinity of the needle bar 20 supported by the needle bar support frame 40, vertical movement of a square piece 55 provided at one end of a link body 54 that applies a driving force for vertical movement to each needle bar 20. A guide groove 42 for guiding the above is formed.

  In addition, one end of a swing shaft 43 that applies a swing driving force for swinging the needle is connected to an intermediate position in the vertical direction at one end of the needle bar support frame 40 in the Y-axis direction. The swing shaft 43 is supported by the sewing machine frame so as to be rotatable along the Y-axis direction, and is connected to a swing mechanism that swings in synchronization with the vertical movement of the needle bar 20. Further, the swing mechanism can adjust the swing angle range from 0 ° to a predetermined angle range with a well-known configuration, and if necessary, the sewing needles held by the needle bars 20 can be moved along the X-axis direction. It is possible to swing the needle with an arbitrary swing width. Further, as described above, the swing mechanism of the needle swing is adjusted so that each needle bar 20 is in a state along the Z-axis direction when the needle swing is not performed.

(Needle bar vertical movement mechanism)
As shown in FIG. 1, the needle bar vertical movement mechanism 50 includes a needle bar holder 51 that supports each needle bar 20 via a clutch mechanism 60, and a sewing machine motor (not shown) that is a vertical movement drive source for each needle bar 20. ) Of the sewing machine main shaft 52, the rotary weight 53 fixedly installed at one end of the sewing machine main shaft 52, the link body 54 connecting the rotary weight 53 and the needle bar holder 51, And a square piece 55 for moving the end on the side of the needle bar along the Z-axis direction.

The needle bar holder 51 is formed with insertion holes through which the two needle bars 20 are inserted in parallel, and the needle bar 20 inserted into each insertion hole is held by the clutch mechanism 60.
The sewing machine main shaft 52 is rotatably supported by the sewing machine frame in a state along the Y-axis direction. One end of the sewing machine main shaft 52 is connected to the sewing machine motor, and the other end is connected to the rotation center position of the disk-shaped rotating weight 53.
The link body 54 is connected so that one end of the link body 54 is eccentric from the center of the rotary weight 53 so as to be rotatable about the Y-axis direction, and the other end is rotatable about the Y-axis direction with respect to the needle bar holder 51. It is connected to.
The square piece 55 provided at the other end of the link body 54 is restricted by the guide groove 42 of the needle bar support frame 40 so as to be movable only along the Z-axis direction (longitudinal direction of the supported needle bar 20). ing. For this reason, one end portion of the link body 54 makes a circular motion together with the rotary weight 53, but the other end portion of the link body 54 only moves up and down. As a result, the needle bar 20 is moved up and down via the needle bar holder 51. A driving force is applied.

(Clutch mechanism)
As shown in FIGS. 1 and 4, the clutch mechanism 60 includes two clutch members 61 inserted into circular support holes 57 penetrating from the front of the needle bar holder 51 to the respective insertion holes, and each clutch member 61. The two driven links 62 that are moved forward and backward individually, the two pressing springs 63 that individually apply the moving force in the forward direction to the clutch members 61 via the driven links 62, and the clutch members 61 are moved backward. Two locking claws 64 that are respectively locked in the state (retracted position), two pressing springs 65 that are respectively pressed in the direction in which each locking claw 64 is locked, and the locking by each locking claw 64 is released And a release pin 66 capable of inputting an operation to be performed from the outside.
The driven link 62 and the release pin 66 correspond to an input member that receives an input of an operating force from the outside for switching between holding and releasing of each needle bar 20.

The two support holes 57 of the needle bar holder 51 are formed along the X-axis direction, and support the substantially cylindrical clutch member 61 slidably along the X-axis direction.
FIG. 5 is a perspective view of the clutch member 61. Each clutch member 61 has a protrusion 61a having a substantially rectangular front end surface at the front end (end on the needle bar 20 side). The tip shape and the size of the protrusion 61a substantially match the shape of the first engagement hole 21 of the needle bar 20, and the first movement of the clutch member 61 (movement toward the needle bar 20 side) causes the first projection hole 61a to move to the first position. Can be inserted into the engagement hole 21. Further, the front end surface 61b of the protrusion of each clutch member 61 is formed in a somewhat inclined state, and can be easily inserted into the first engagement hole 21.
When the protrusion 61 a of the clutch member 61 is inserted into the first engagement hole 21, the needle bar 20 is held with respect to the needle bar holder 51, and the needle bar 20 can be moved up and down together with the needle bar holder 51. It becomes possible. When the protrusion 61a of the clutch member 61 is inserted into the first engagement hole 21, the lower end of the swing plate 25 provided in the groove 24 of the needle bar 20 is pressed, and the lower end moves backward. In addition, the upper end moves forward.
Furthermore, a notch 61c is formed at the lower part of the protrusion 61a of each clutch member 61, and the tip of the locking claw 64 is locked. The notch 61c is engaged with the locking claw 64 only when the clutch member 61 is retracted to a predetermined retracted position (a position where the protrusion 61a at the tip thereof does not reach the first engagement hole 21 of the needle bar 20). It is provided at a position where it can be stopped.

Each of the two driven links 62 functions as an input member for inputting an operating force for switching the clutch member 61 from the holding state of the corresponding needle bar 20 to the released state.
Each driven link 62 is formed in a bent shape in the middle thereof, and is supported by the needle bar holder 51 so as to be swingable at the bent intermediate portion. One end of the driven link 62 is connected to the rear end of the clutch member 61, and the other end is always pressed by the pressing spring 63. The pressing spring 63 presses the driven link 62 so as to swing in the direction in which the clutch member 61 moves forward.
Further, each driven link 62 is pressed from below by the pressing spring 63 against the other end portion. When the clutch member 61 is moved backward, the other end of the driven link 62 is moved by the upward movement of the needle bar holder 51. The contact protrusion 81a of the switching member 81 of the switching mechanism 80, which will be described later, is brought into contact with the portion from above, and the clutch member 61 can be moved backward by being pushed down and rocked against the pressing spring 63. ing.

  Each locking claw 64 is supported by a needle bar holder 51 so as to be swingable below the clutch member 61. Each of the locking claws 64 can swing up and down at its swing end, and swings upward to enter the notch 61c of the clutch member 61 whose tip end is in the retracted position. It is possible to hold so as not to. Each pressing spring 65 always presses each locking claw 64 upward from below. For this reason, the claw tip of the locking claw 64 is urged toward the clutch member 61, and the claw tip is quickly inserted when the clutch member 61 moves backward and the notch 61c reaches the claw position. The

The release pin 66 functions as an input member for inputting an operating force for switching to the holding state when the needle bar 20 is in the released state.
The release pin 66 is provided through the needle bar holder 51 up and down from the upper end portion of the needle bar holder 51 to reach each locking claw 64 through the respective clutch members 61 and is movable up and down. It is supported. The lower end portion of the release pin 66 is disposed so as to be simultaneously contactable with a contact portion (not shown) provided on each locking claw 64. In other words, the half region of the lower end surface of the release pin 66 is in contact with the contact portion of one locking claw 64, and the remaining half region is in contact with the contact portion of the other locking claw 64. Yes.
The release pin 66 is always pressed upward by a spring (not shown), and the upper end of the release pin 66 protrudes above the needle bar holder 51. The upper end portion of the release pin 66 is pressed downward by the contact protrusion 81a of the switching member 81 of the switching mechanism 80, which will be described later, by the upward movement of the needle bar holder 51, and is in the locked state. The tip of the locking claw 64 is pushed downward to release the locking.
The release pin 66 can be switched to the holding state regardless of which of the two needle bars 20 is in the release state, but a separate release pin may be provided for each needle bar 20. In that case, it is necessary to arrange any release pin 66 within the movement range of the contact protrusion 81 a of the switching member 81.

(Switching mechanism)
The switching mechanism 80 includes a guide groove portion 82 formed in the needle bar support frame 40 at a position slightly above the top dead center of the needle bar holder 51, and a switching member 81 slidably supported along the guide groove portion 82. And a pressing cover 83 that prevents the switching member 81 from falling off the guide groove 82.
The guide groove portion 82 is formed along the Y-axis direction in the upper portion of the needle bar support frame 40, and supports the switching member 81 so as to be slidable along the same direction.

The switching member 81 has a substantially prismatic shape as a whole, an abutting projection 81a projecting in a direction perpendicular to the longitudinal direction is formed at one end, and the other end is provided outside the sewing machine frame. Not connected to operation input means.
The switching member 81 is supported by the guide groove portion 82 in a state where the contact protrusion 81a is directed downward. Then, the movement of the switching member 81 along the Y-axis direction pushes one of the driven links 62, the other driven link 62, or the release pin 66 of the clutch mechanism 60 when the needle bar holder 51 reaches the top dead center. The contact protrusion 81a can be switched to a possible position. The contact protrusion 81a is switched by an artificial operation on the operation input means described above from outside the sewing machine frame. The contact protrusion 81a can be pushed downward by the stroke required for each release operation with respect to each of the driven links 62 and 62 and the release pin 66 of the needle bar holder 51 raised to the top dead center position. The protruding length is set.

(Stopper mechanism)
The stopper mechanism 70 includes a support portion 72 having two circular through holes penetrating from the front surface of the needle bar support frame 40 to the insertion hole of the needle bar 20 at the upper end portion of the needle bar support frame 40, and each of the support portions 72. Two stopper members 71 inserted into the through holes, two pressing springs 73 that individually apply a moving force in the forward direction (needle bar 20 side) to each stopper member 71, and each pressing spring 73 are supported in the rear. And a cover body 74 that covers and closes the through hole of the support portion 72.

Each through hole of the support portion 72 is formed along the X-axis direction, and supports the substantially cylindrical stopper member 71 so as to be slidable along the X-axis direction.
FIG. 6 is a perspective view of the stopper member 71. Each stopper member 71 has a tip 71a (end on the needle bar 20 side) having a rectangular shape when viewed from the front in the X-axis direction, and a tip having a semicircular shape when viewed from the side in the Y-axis direction. Yes. The shape of the tip 71a corresponds to the shape of the second engagement hole 22 described above.
As described above, the stopper member 71 is pressed forward from the rear by the pressing spring 73. When the leading end 72 a of the stopper member 72 is inserted into the second engagement hole 22 by such pressing, the needle bar 20 is prevented from moving up and down with respect to the needle bar support frame 40.

However, the force for swinging the swinging plate 25 by the pressing force of the pressing spring 73 against each stopper mechanism 71 swings the swinging plate 25 by the pressing force that the pressing spring 65 applies to the clutch member 61 via the driven link 62. It is set smaller than the force to move. Therefore, when the projection 61a of the clutch member 61 and the tip 71a of the stopper member 71 are to be inserted into the first engagement hole 21 and the second engagement hole 22, respectively, the projection 61a of the clutch member 61 is The tip 71a of the stopper member 71 is pushed and lost so that it cannot enter the second engagement hole 22.
Further, when the distal end portion 71a of the stopper member 71 is inserted into the second engagement hole 22, the upper end portion of the swinging plate 25 provided in the groove portion 24 of the needle bar 20 is pressed, and the upper end portion is advanced. The lower end can be moved backward while being moved.

  Note that the distance in the Z-axis direction from the clutch member 61 of the clutch mechanism 60 to the stopper member 71 of the stopper mechanism 70 when the needle bar holder 51 is at the top dead center is from the first engagement hole 21 of the needle bar 20. The distance is set so as to coincide with the distance to the second engagement hole 22. Thus, when the needle bar holder 51 is at the top dead center position, the needle bar 20 can be switched to the holding state by the stopper mechanism 70 or the held needle bar 20 can be engaged with the clutch mechanism 60. Yes.

(Grease supply means)
FIG. 7A is a plan view of the needle bar holder equipped with the impregnating member 91, and FIG. 7B is a plan view of the needle bar holder attached with the impregnated member 91. As shown in each figure (particularly, FIGS. 4, 7, and 10), the impregnation member 91 as the grease supply means is a sheet-like felt material soaked with grease, and from the upper surface to the rear surface of the needle bar holder 51. Is provided on the needle bar holder 51 so as to cover substantially the entire bottom surface. The impregnating member 91 is formed with two insertion holes 92 through which the needle bar 20 is inserted at portions corresponding to the upper surface and the bottom surface of the needle bar holder 51. The impregnating member 91 is attached to the needle bar holder 51 by a well-known method such as bonding or a pinching structure provided on the needle bar holder 51, and at the time of mounting, each needle bar 20 is inserted into each needle bar insertion hole 92. The Each insertion hole 92 is set to have an inner diameter equal to or slightly smaller than the outer diameter of the needle bar 20 so that the inner peripheral portion of each insertion hole 92 and the outer peripheral surface of each needle bar 20 are in close contact with each other. It has become. As a result, when the needle bar 20 slides with respect to the needle bar holder 51 such as when one needle is stopped, it is possible to sufficiently apply grease from the impregnating member 91 to the outer peripheral surface of the needle bar 20. ing.
Further, as the sewing machine is driven, grease is supplied from the impregnation member 91 to the clutch mechanism 60 to the switching member 81 by scattering, flowing down, or the like.

The sewing machine shown in the present embodiment causes the needle bar mechanism 10 provided in the surface portion of the sewing machine frame to slide by a grease supply means (not shown) in addition to the impregnation member 91 and the supply member 41 described above. Grease lubrication of the part is aimed at.
The impregnation member 91 is a felt material, but is not particularly limited to this, and any material can be used as long as it retains grease such as non-woven fabric, various fiber materials, and porous materials, and can supply grease by sliding contact. good.

(Material selection of switching member and input member)
FIG. 8 is a diagram showing a result of comparing the amount of wear at the time when a collision piece made of a uniform material collides with a sample made of various materials under the same conditions. In the test, each sample was subjected to a load of 13 [N] on the collision piece in a non-lubricated environment where no lubricant was used. It was done by colliding 6 × 10 ⁶ times. Moreover, in FIG. 7, the wear amount of the sample which showed the wear amount of the sample which consists of the softest carburizing case hardening steel as 1 was shown.

(1) According to the test results, the tool steel had higher hardness than the carburized case-hardened steel, and the wear amount was 0.8 over that of the carburized case-hardened steel.
(2) Moreover, the material which performed the fine particle shot process to the carburizing case-hardening steel had hardness higher than the carburizing case-hardening steel which does not process, and the abrasion loss became 0.8 weak with respect to the carburizing case hardening steel.
In particular, the fine particle shot treatment can improve wear resistance by improving the fatigue strength by removing residual stress and improving the grease retaining effect by forming dimples.
As the sample, a sample made by irradiating fine particles made of ceramics having a diameter of 40 [μm] for 1 minute at an injection speed of 200 [m / s] was used.
(3) Further, the high carbon alloy steel has a higher hardness than the carburized case-hardened steel, and the wear amount is 0.4 over that of the carburized case-hardened steel.
Here, as the high carbon alloy steel, iron containing 0.7% of carbon was used.
(4) Further, the material obtained by nitriding the carburized case-hardened steel has higher hardness than the carburized case-hardened steel not subjected to the treatment, and the amount of wear was 0.4 less than that of the carburized case-hardened steel.
As the nitriding treatment, a sample obtained by ion nitriding treatment was used. In addition, a white layer having a thickness of about 1 [μm] formed by nitriding was used.
(5) In addition, the material obtained by nitriding chromium-containing high carbon alloy steel had higher hardness than carburized case-hardened steel, and the wear amount was 0.1 or higher than carburized case-hardened steel.
Here, as the high carbon alloy steel, a steel containing 0.7% of carbon and 0.9% of chromium was used.
As the nitriding treatment, a sample obtained by ion nitriding treatment was used. In addition, a white layer having a thickness of about 1 [μm] formed by nitriding was used.

The above-described switching member 81 of the switching mechanism 80 is any one of the driven links 62 regardless of which of the needle bars is switched, and whether the switching to the holding state or the releasing state is performed. Since the collision is performed with respect to the release pin 66, the number of collisions is the highest as compared with the driven link 62 and the release pin 66.
For this reason, the switching member 81 was formed of a material obtained by nitriding the chromium-containing high carbon alloy steel that showed the highest wear resistance in the comparative test. For this material, a material having a hardness of 800 [HV] was used.

The driven link 62 and the release pin 66 of the clutch mechanism 60 collide with the switching member 81 when any one of the needle bars 20 is switched to the released state or switched to the held state, and thus is resistant to wear due to the collision. Selected material. However, considering that the frequency of collision is not as high as that of the switching member 81, a material obtained by subjecting carburized case-hardened steel having a lower resistance than the switching member 81 to a fine particle shot treatment was used. For this material, one having a hardness of 700 [HV] was used.
Further, the clutch member 61 and the locking claw 64 that are likely to receive fretting wear due to the collision between the switching member 81 and the driven link 62 or the release pin 66 are formed from the same material as the driven link 62 and the like.

(Description of the operation of the needle bar mechanism of the two-needle sewing machine)
The operation of the needle bar mechanism 10 of the two-needle sewing machine will be described with reference to FIGS. FIGS. 9 and 11 are explanatory views of the operation of the needle bar mechanism 10, respectively. FIG. 10 is a cross-sectional view of the needle bar mechanism 10 with a cross section passing through the center line of one needle bar 20 in the operation state of FIG.
1 and 4 show a state in which each needle bar 20 is held by a needle bar holder 51 at the top dead center position, and the description of the operation starts here.

By driving the sewing machine motor, a downward moving force is applied to the needle bar holder 51 via the sewing machine main shaft 52, the rotary weight 53 and the link body 54 of the needle bar vertical movement mechanism 50. As a result, the needle bar holder 51 moves to the bottom dead center together with the two needle bars 20 (state shown in FIG. 3).
When one needle bar 20 (here, the left needle bar 20 will be described as an example) is stopped, the needle bar hug 51 starts to descend and returns to top dead center again. In the meantime, an operation input means (not shown) provided outside the sewing machine frame is operated to align the contact protrusion 81a of the switching member 81 with the upper position of the left driven link 62.

When the needle bar holder 51 is again moved to the top dead center by driving the sewing machine motor, the contact protrusion 81a of the switching member 81 presses the left driven link 62 downward (states of FIGS. 9 and 10).
As a result, the left driven link 62 moves the clutch member 61 in the backward direction against the pressing spring 63, and as a result, the leading end of the locking claw 64 below the clutch member 61 is moved to the pressing spring 65. The clutch member 61 is pushed so as not to move forward by being pushed into the notch 61c.
Further, when the clutch member 61 moves backward, the clutch member 61 comes out of the first engagement hole 21, and the lower end portion of the swing plate 25 in the groove portion 24 of the left needle bar 20 is released from the pressed state. The distal end portion of the stopper member 71 that has been in pressure contact enters the second engagement hole. As a result, the left needle bar 20 is held by the needle bar support frame 40 at the top dead center position.

Then, as shown in FIG. 11, when the needle bar holder 51 moves down again, only the right needle bar 20 moves down together with the needle bar holder 51, and the left needle bar 20 remains at the top dead center position. As a result, sliding occurs between the needle bar holder 51 and the left needle bar 20, but at the same time, the impregnation member 91 supplies the needle bar 20 by applying grease.
In order to move the needle bar 20 up and down again from this state, an operation input means (not shown) provided outside the sewing machine frame is operated between the start of the lowering of the needle bar holder 51 and the return to the top dead center. Then, the contact protrusion 81 a of the switching member 81 is aligned with the upper position of the release pin 66.
When the needle bar holder 51 is moved again to the top dead center by driving the sewing machine motor, the contact protrusion 81a of the switching member 81 presses the release pin 66 downward (state shown in FIGS. 1 and 4).
Thereby, the lower end portion of the release pin 66 presses the contact portion of the left locking claw 64, and moves the distal end portion of the locking claw 64 downward against the pressing spring 65. As a result, the latching claw 64 is released from the latched state of the clutch member 61 with the notch 61c, and the clutch member 61 is moved forward by being pressed by the pressing spring 63. The clutch member 61 enters the first engagement hole 21 of the needle bar 20 held by the needle bar support frame 40, presses the lower end of the swing plate 25, and presses the upper end. 71 is pushed back and sent out of the second engagement hole 22.
As a result, the state where the needle bar 20 is held by the stopper member 71 is released, the needle bar 20 is held by the needle bar holder 51, and starts to move up and down again.

(Effect of embodiment)
As described above, in the feeding device 10 of the sewing machine, since the switching member 81 is formed of the nitrided chromium-containing high carbon alloy steel, compared to the case of using a simple carburized case-hardened steel or tool steel, Hardness increases, and corrosion resistance and wear resistance are improved. Therefore, these changes in characteristics improve durability against fretting wear caused by repeated collisions and maintain normal operation over a long period of time even in a grease lubrication environment where the lubrication effect is suppressed. It becomes possible to do.
Further, since the switching member 91 is formed with a white layer having high hardness and brittle characteristics at the collision portion of the switching member, the white layer protects the base material between the base material of the switching member and the input member at the time of collision. Even in a grease lubrication environment, durability against fretting wear can be further improved, and normal operation can be maintained for a longer period of time.

In addition, since the follower link 62 and the release pin 66 of the clutch mechanism 60 are made of carburized case-hardened steel subjected to fine particle shot processing, the hardness is higher than when using only carburized case-hardened steel or tool steel. In addition, fatigue resistance and wear resistance are improved. Therefore, these characteristics change improve durability against fretting wear caused by repeated collisions even in a dry environment with poor lubrication, and can maintain normal operation over a long period of time. It becomes.
Furthermore, since the driven link 62 of the clutch mechanism 60 uses a material having lower hardness than the switching member 81 having a high collision frequency, the balance of durability is further improved. Thus, durability can be improved and normal operation can be maintained for a longer period of time.

Further, since the inside of the surface portion of the sewing machine is grease-lubricated, it is possible to ensure a smooth sewing operation of the sewing machine while suppressing the leakage of the lubricant to the sewing object side.
Further, since the grease is supplied to the sliding portion between the needle bar holder 51 and the needle bar 20 of the needle bar mechanism 10 by the impregnating member 91, even when the holding of any needle bar 20 is released, the needle bar holder 51 is released. Can be smoothly moved up and down. Therefore, it is possible to smoothly perform sewing in the sewing machine. At this time, since the impregnation member 91 is provided on the needle bar holder 51, the grease is supplied only when the relative movement occurs between the needle bar 20 and the needle bar holder 51, and the grease consumption amount is reduced. Reduction can be achieved.
Further, since the grease is supplied by the impregnating member 91 that impregnates and holds the grease, the grease can be supplied simply by being brought into sliding contact with the impregnating member 91, and a path for storing the grease or moving to the supply site is provided. Therefore, the structure can be simplified. Therefore, it is possible to improve the productivity of the needle bar mechanism.

(Other)
In the above embodiment, the support of the needle bar 20 is supported by the needle bar rocking base (needle bar support frame 40) of the needle swing mechanism. However, the needle bar support is not necessarily required. The body only needs to support the needle bar so as to be movable up and down, and for example, the body may be fixed to a sewing machine frame.

In the above embodiment, the switching member 81 is entirely formed of a chromium-containing high carbon alloy steel that is nitrided. However, the present invention is not limited to this, and a chromium-containing high carbon alloy steel that is nitrided only in a portion that causes a collision is mounted. Alternatively, nitriding treatment may be applied only to a portion where collision occurs with the base material being chromium-containing high carbon alloy steel.
Similarly, with respect to the driven link 62 and the release pin 66, carburized case-hardened steel subjected to the fine particle shot processing only on the portion where the collision occurs is mounted, or the fine particle shot processing is performed only on the portion where the collision occurs using the base material as the carburized case-hardened steel. You may give it.
Further, as can be seen from the comparison of FIG. 8, the fine particle shot treatment is not limited to carburized case-hardened steel, but may be applied to other materials. For example, a high-carbon alloy steel (which may or may not contain chromium) may be used for the switching member 81 or may be used for the follower link 62 and the release pin 66 after being subjected to a fine particle shot treatment. good.
Further, each member that operates the switching member 81 and the clutch mechanism 60 may be provided with supply means such as an impregnation member 91 that impregnates grease and supplies grease by sliding contact.

It is a front view of the needle bar mechanism of the two needle sewing machine which is an embodiment of the invention, and shows the state which exists in the top dead center position in the two needle holding state. 2A is a side view of the needle bar, and FIG. 2B is a front view. It is a front view of the needle bar mechanism of a two-needle sewing machine, and shows a state at the bottom dead center position in a two-needle holding state. It is sectional drawing of the needle bar mechanism by the cross section along the XZ plane while passing the centerline of one needle bar in the operation state of FIG. It is a perspective view of a clutch member. It is a perspective view of a stopper member. FIG. 7A is a plan view of a needle bar holder equipped with an impregnation member, and FIG. 7B is a plan view of a needle bar holder equipped with an impregnation member. It is a figure which shows the result of having collided the collision piece which consists of a uniform material with respect to the sample which consists of various materials on the same conditions, and compared the amount of wear at that time. It is a front view of the needle bar mechanism of a two-needle sewing machine, and shows a state immediately after releasing the holding state of one needle bar. FIG. 10 is a cross-sectional view of the needle bar mechanism that passes through the center line of one needle bar in the operation state of FIG. 9 and is a cross section along the XZ plane. It is a front view of the needle bar mechanism of a two-needle sewing machine, and shows a state where the holding state of one needle bar is released and moved to the bottom dead center.

Explanation of symbols

10 Needle bar mechanism of two-needle sewing machine 20 Needle bar 40 Needle bar support frame (needle bar support)
50 Needle bar vertical movement mechanism 51 Needle bar holding mechanism 60 Clutch mechanism
61 Clutch member 62 Driven link (input member)
64 Locking claw 66 Release pin (input member)
80 switching mechanism 81 switching member 81a contact protrusion 91 impregnation member

Claims (8)

A needle bar support that individually supports a pair of needle bars to be movable up and down;
A needle bar up-and-down moving mechanism for moving up and down each needle bar using a needle bar holding that individually holds the pair of needle bars;
A clutch mechanism that includes a plurality of input members that receive the input of an operating force from the outside that holds and releases each needle bar with respect to the needle bar hug, and switches between holding and releasing the needle bar,
A switching member that selectively makes contact with any input member by the lifting and lowering operation of the clutch mechanism and performs switching between holding and releasing of each needle bar,
In the needle bar mechanism of a two-needle sewing machine having a one-needle stop function capable of selectively stopping the vertical movement of the pair of needle bars,
A needle bar mechanism for a two-needle sewing machine, comprising: a grease supply means that is provided on the needle bar holder and supplies grease to a sliding portion between the needle bar holder and each needle bar.   The needle of the two-needle sewing machine according to claim 1, wherein the grease supply means is an impregnation member that impregnates and holds grease, and is provided in the needle bar holder so as to be in sliding contact with the needle bars. Bar mechanism. A needle bar support that individually supports a pair of needle bars to be movable up and down;
A needle bar up-and-down moving mechanism for moving up and down each needle bar using a needle bar holding that individually holds the pair of needle bars;
A clutch mechanism that includes a plurality of input members that receive the input of an operating force from the outside that holds and releases each needle bar with respect to the needle bar hug, and switches between holding and releasing the needle bar,
A switching member that selectively makes contact with any input member by the lifting and lowering operation of the clutch mechanism and performs switching between holding and releasing of each needle bar,
In the needle bar mechanism of a two-needle sewing machine having a one-needle stop function capable of selectively stopping the vertical movement of the pair of needle bars,
And a grease supply means for supplying grease to at least one of the clutch mechanism and the switching member while being provided in the needle bar hug,
A needle bar mechanism for a two-needle sewing machine characterized in that at least a contact portion of the switching member with the input member is made of high carbon alloy steel that is nitrided and contains chromium.   4. A needle bar mechanism for a two-needle sewing machine according to claim 3, wherein a compound layer is formed by nitriding the switching member.   The needle bar mechanism of a two-needle sewing machine according to claim 3 or 4, wherein at least a contact portion of each input member with the switching member is made of high carbon alloy steel subjected to fine particle shot processing.   The surface hardness of the contact portion of the switching member with the input member is higher than that of the contact portion of the input member with the switching member. 5. A needle bar mechanism of a two-needle sewing machine according to 5. A needle bar support that individually supports a pair of needle bars to be movable up and down;
A needle bar up-and-down moving mechanism for moving up and down each needle bar using a needle bar holding that individually holds the pair of needle bars;
A clutch mechanism that includes a plurality of input members that receive the input of an operating force from the outside that holds and releases each needle bar with respect to the needle bar hug, and switches between holding and releasing the needle bar,
A switching member that selectively makes contact with any input member by the lifting and lowering operation of the clutch mechanism and performs switching between holding and releasing of each needle bar,
In the needle bar mechanism of a two-needle sewing machine having a one-needle stop function capable of selectively stopping the vertical movement of the pair of needle bars,
And a grease supply means for supplying grease to at least one of the clutch mechanism and the switching member while being provided in the needle bar hug,
2. A needle bar mechanism for a two-needle sewing machine, wherein at least a contact portion of each input member with the switching member is carburized case-hardened steel subjected to fine particle shot processing. The needle bar mechanism of the two-needle sewing machine according to any one of claims 1 to 7 is provided inside the surface portion of the sewing machine frame,
A two-needle sewing machine characterized in that the inside of the surface portion of the sewing machine frame is grease lubricated.

Images