JP2001113075A - Sliding device for sewing machine, and sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a sliding device for a sewing machine, and a sewing machine using the sliding device positively prevented from the wear and seizure damage of sliding parts in the unlubricated state over a long period of time. SOLUTION: In this sliding device 10 for a sewing machine, at least one of a sliding surface 11a of a sliding part 11 and a slide receiving surface 15a of a support part 15 is formed of a coating layer 22 comprising carbide carbon, and the sliding device 10 is used for the sewing machine M.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sliding device for a sewing machine and a sewing machine, and more particularly, to a sliding portion in which a sliding surface of a movable sliding component is supported by a sliding surface of a supporting component. The present invention relates to a sliding device for a sewing machine and a sewing machine.

[0002]

2. Description of the Related Art Generally, in a sewing machine, at least one of a pair of components represented by a driving force transmission mechanism, a balance mechanism, a needle bar mechanism, a presser mechanism and the like is movable. Are provided everywhere where the sliding part is supported so as to contact the other part. A sliding device for a sewing machine used for a sliding portion of such a conventional sewing machine, for example, a sliding portion of a needle bar that reciprocates at the time of a sewing operation and a needle bar metal that supports the needle bar is used for the operation of the sewing machine. At the same time, the generation of wear powder due to the wear of the sliding parts,
It is known that a sliding resistance (frictional resistance) is generated at a sliding portion to generate heat, and the heat generated causes seizure damage such that the needle bar is seized with the needle bar metal.

[0003] In order to prevent the generation of wear powder and seizure damage due to the abrasion of such sliding parts, in a conventional sewing machine, lubricating oil is forcibly supplied to the sliding parts of a sliding device for sewing machines. A lubricating film is formed to prevent the generation of abrasion powder and seizure damage due to abrasion.

However, when an oil supply mechanism for forcibly supplying lubricating oil is provided at a sliding portion of a sliding device for a sewing machine, for example, a sliding portion between a needle bar and a needle bar metal, the needle bar and the needle bar are not provided. Supply of lubricating oil to the sliding part with needle bar metal (lubrication)
Is performed by attaching the lubricating oil scattered in the surface of the sewing machine to the outer peripheral surface of the needle bar that moves up and down, so that the lubricant has high fluidity in order to scatter the lubricant inside the surface. Therefore, it is necessary to use a low-viscosity lubricating oil, and the lubricating oil easily leaks from the sliding portion between the needle bar and the needle bar metal. There is a problem that it is difficult to control the amount of lubricating oil (the amount of lubricating oil) to be attached to the outer peripheral surface and it takes a lot of time.

That is, when the amount of lubricating oil supplied to the sliding portion is large, the lubricating oil leaks from the sliding portion, and conversely, when the amount of lubricating oil supplied to the sliding portion is small, the lubricating oil is supplied. There has been a problem that the moving part may be seized and damaged, and may not be able to maintain a stable function for a long period of time.

In addition, the structure for supplying the lubricating oil to the sliding portion has a problem that the structure of the sewing machine is complicated, the number of parts and the time required for assembly are increased, and the economical burden is increased. Was.

Therefore, in recent years, there has been a demand for oilless lubrication of the sewing machine. The surface of a steel material which is less likely to suffer from abrasion or seizure of sliding parts during operation of the sewing machine without forcibly lubricating the machine from the outside. There has been proposed a sliding device for a sewing machine in which a hardened layer is provided by performing a surface treatment such as carburizing and quenching or ion nitriding, or an alumite treatment is applied to the surface of an aluminum material.

In recent years, in a sewing machine such as a lock sewing machine which operates at a high speed, a sliding device for a sewing machine having a hard coating layer such as TiN, ceramics, DLC (diamond-like carbon) provided on the surface of a steel material. Has been proposed.

[0009]

However, in a conventional sliding device for a sewing machine in which a hardened layer is formed by performing a surface treatment such as carburizing or ion nitriding on the surface of a steel material, the wear resistance in a non-lubricated state is considered. However, it is insufficient as a sliding device for sewing machines, cannot maintain stable functions over a long period of time, requires lubrication to sliding parts, and cannot achieve oil-free sewing machines. There was a problem.

In a conventional sliding device for a sewing machine in which an alumite coating is applied to the surface of an aluminum material to provide an alumite coating, the friction coefficient is large, and the coating is easily cracked. Is not sufficient as a sliding device for sewing machines, cannot maintain stable functions over a long period of time, requires lubrication to sliding parts, and cannot achieve oilless lubrication of sewing machines. There was a problem.

Further, in a conventional sliding device for a sewing machine provided with a hard coating layer such as TiN or ceramics,
The frictional resistance is large, and the hardness of the coating is high, so the heat generated at the sliding part is high, and the mating parts in contact with the coating layer are worn away. Is inadequate, cannot maintain a stable function for a long period of time, needs lubrication to sliding parts, and has a problem that oil-free sewing machines cannot be realized.

Furthermore, in a sliding device for a sewing machine provided with a hard coating layer such as DLC, the friction coefficient is small, but the adhesion of the coating is inferior, and the coating itself has an Hv300.
Since it is as hard as 0, it will wear the mating part in contact with the coating layer, so that the durability in the oil-free state is not enough for a sliding device for sewing machines, and it is possible to maintain a stable function for a long time. However, there is a problem in that lubrication is required for the sliding portion, and no lubrication of the sewing machine cannot be realized.

[0013] Therefore, there is a need for a sewing machine sliding device and a sewing machine using the sewing machine sliding device that can reliably prevent wear and seizure damage of sliding portions without lubrication for a long period of time.

The present invention has been made in view of these points, and provides a sliding device for a sewing machine and a sewing machine which can reliably prevent wear and seizure damage of a sliding portion without lubrication for a long period of time. The purpose is to do.

[0015]

In order to achieve the above-mentioned object, a sliding device for a sewing machine according to the present invention according to claim 1 is characterized in that a sliding surface of a sliding component and a cover of a supporting component are provided. At least one of the sliding surfaces is formed of a coating layer made of carbide and carbon. And by adopting such a configuration, the coating layer has a low coefficient of friction,
It has a self-lubricating property, large load resistance and adhesion, and does not cause the phenomenon of polishing the sliding surface of the contacting supporting component, so that it maintains a stable function without lubrication for a long time. be able to.

A feature of the sliding device for a sewing machine according to the second aspect of the present invention resides in that the coating layer is formed by PVD. And by adopting such a configuration, the coating layer can be efficiently and reliably formed,
Since the processing temperature at the time of forming the coating layer can be performed at a low temperature of about 250 ° C., there is almost no influence such as a decrease in hardness of the main body which is a base material coated with the coating layer.

According to a third aspect of the present invention, the sliding device for a sewing machine according to the present invention is characterized in that the coating layer has a layered film structure, and that the carbide-rich layer and the carbon-rich layer are alternately arranged. is there. And, by employing such a configuration, the carbide-rich layer can absorb a load, so that a large load resistance can be easily obtained.

A feature of the sliding device for a sewing machine according to the present invention according to claim 4 is that the coating layer has a thickness of 0.5 to 4.0 μm. By adopting such a configuration, it is possible to obtain the most preferable thickness necessary for maintaining a stable function without lubrication for a long period of time.

A feature of the sliding device for a sewing machine according to the present invention according to claim 5 is that the main body of the component forming the coating layer is formed of a steel material. By adopting such a configuration, since the main body has excellent mechanical strength, a sliding component or a supporting component requiring high strength can be easily obtained.

A feature of the sliding device for a sewing machine according to the present invention according to claim 6 is that a main body of a part forming a coating layer is formed by covering the surface of a steel material with an intermediate film made of chromium. And, by adopting such a configuration, the interlayer can prevent the surface of the main body from being damaged by increasing the hardness of the surface of the main body, and can also improve the corrosion resistance. From the coating layer can be prevented from peeling off.

According to a seventh aspect of the present invention, the sliding device for a sewing machine according to the present invention is characterized in that the main body of the component forming the coating layer is formed by covering the surface of aluminum or an aluminum alloy with an intermediate film made of chromium. It is in. And
By adopting such a configuration, the intermediate film can prevent the surface of the main body formed of the soft material from being damaged and deformed by increasing the hardness of the surface of the main body, and can also prevent the coating layer from being formed from the main body. Can be prevented from peeling off.

An eighth feature of the sliding device for a sewing machine according to the present invention resides in that the thickness of the intermediate film is 2 to 4 μm.
By adopting such a configuration, it is possible to more reliably prevent the surface of the main body from being damaged and the coating layer from peeling off from the main body.

According to a ninth aspect of the present invention, a sliding device for a sewing machine according to the present invention is characterized in that a main body of a part forming a coating layer is formed by covering the surface of a steel material with an intermediate film made of a nickel alloy. . And, by adopting such a configuration, the interlayer can prevent the surface of the main body from being damaged by increasing the hardness of the surface of the main body, and can also improve the corrosion resistance. From the coating layer can be prevented from peeling off.

According to a tenth aspect of the present invention, a sliding device for a sewing machine according to the present invention is characterized in that a body of a component forming a coating layer is formed by covering the surface of aluminum or an aluminum alloy with an intermediate film made of a nickel alloy. On the point.
And, by adopting such a configuration, the intermediate film can prevent the surface of the main body formed of the soft material from being damaged and deformed by increasing the hardness of the surface of the main body. The coating layer can be prevented from peeling off.

A feature of the sliding device for a sewing machine according to the present invention according to claim 11 is that the thickness of the intermediate film is 7 to 10 μm. By adopting such a configuration, it is possible to more reliably prevent the surface of the main body from being damaged and the coating layer from peeling off from the main body.

According to a twelfth aspect of the present invention, a sliding device for a sewing machine is the sliding device for a sewing machine according to any one of the first to eleventh aspects.
And by adopting such a configuration, it is possible to easily realize oil-free lubrication of the sliding portion.

A thirteenth aspect of the present invention is characterized in that grease is interposed between the sliding surface and the sliding surface. By adopting such a configuration, the durability of the sliding portion in the non-lubricating state can be further improved.

[0028]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to embodiments shown in the drawings.

FIGS. 1 to 3 show an embodiment of a sewing machine according to the present invention using the sliding device for a sewing machine according to the present invention. FIG. 1 is a front view of a main part, and FIG. FIG. 3 is an enlarged cross-sectional view taken along line 3-3 of FIG.

The sewing machine according to the present embodiment, as a sliding device for a sewing machine, slides a reciprocating needle bar as a movable sliding component and a needle bar metal as a support component for supporting the needle bar. The moving part is made non-lubricated, and the sliding surface of the needle bar is formed by a coating layer made of carbide and carbon.

As shown in FIG. 1, the sewing machine M according to the present embodiment
An upper shaft 4 is disposed inside a sewing machine arm 2 constituting a part of the sewing machine main body 1 with its axis substantially parallel to a sewing machine bed (not shown). A rear end (not shown) of the upper shaft 4 shown on the right side in FIG. 1 protrudes outside the sewing machine main body 1, and a rear end of the upper shaft 4 protruding outside the sewing machine main body 1 has a rear end. And a pulley (not shown). The driving force of the sewing machine motor arranged at the rear end of the sewing machine bed is transmitted to the pulley via a timing belt (both not shown) or the like.
The upper shaft 4 is formed so as to be rotatable by the driving force of the sewing machine motor. Further, the vicinity of the tip of the sewing machine arm 2 shown on the left side in FIG. 1 is a so-called surface portion 5. Inside the surface portion 5, the tip of the upper shaft 4 shown on the left side in FIG. It is configured.

A counterweight 6 is disposed on the outer peripheral surface of the tip of the upper shaft 4. A needle bar crank 7 is attached to a distal end side of the counterweight 6 shown on the left side of FIG. 1, and the needle bar crank 7 has a base end of a needle bar crank rod 8 shown in the upper part of FIG. Department is attached. Further, a needle bar clamp 9 is attached to the distal end of the needle bar crank rod 8 shown in the lower part of FIG.
, A substantially central portion in the axial direction of a needle bar 11 that constitutes a part of the sliding device 10 for a sewing machine according to the present invention is fixed.
Further, a link balance (only part of which is shown) connected to a balance crank 13 supported by a balance support shaft 12 disposed on the sewing machine main body 1 is attached to the needle bar crank 7.

Inside the surface 5 of the sewing machine arm 2,
A pair of upper and lower needle bar metals 15 that support the needle bar 11 so as to be able to reciprocate in the vertical direction are provided, and a part of the sliding device 10 for a sewing machine of the present embodiment is provided by the needle bar metals 15. It is configured. And a pair of needle bar metal 1 up and down
One of the upper part of FIG. 1 shown in FIG. 1 is a needle bar upper metal, and the other one of the lower part shown in FIG. 1 has its lower end exposed outside the surface 5 of the sewing machine arm 2, that is, outside the sewing machine main body 1. It is the metal under the needle bar.

The sewing machine M of this embodiment has a needle bar 11 and a needle bar metal 15 constituting the sliding device 10 for the sewing machine.
There is no oil supply mechanism for forcibly supplying the lubricating oil to the sliding portion between them, and an oil supply amount adjusting mechanism for adjusting the lubricating oil supply amount.

The needle bar 11 and each needle bar metal 15 constituting the sliding device 10 for the sewing machine will be described in more detail.

As shown in FIGS. 2 and 3, the sliding device for sewing machine 10 of the sewing machine M according to the present embodiment includes a needle bar 11 as a movable sliding part, and a supporter for supporting the needle bar 11. Needle bar metal 15 as a part
The sliding surface 11 a provided on the outer peripheral surface of the needle bar 1 is supported by the slidable surface 15 a provided on the inner peripheral surface of each needle bar metal 15.

The needle bar 11 of the present embodiment is a needle bar main body 2 as a main body formed of a steel material into a substantially cylindrical predetermined shape.
One. The outer peripheral surface of the needle bar main body 21 is shown in FIG.
This coating layer 2 is exaggerated in FIG.
Most of the outer peripheral surface of 2 is a sliding surface 11a supported by a sliding surface 15a formed on the inner peripheral surface of the needle bar metal 15.

The coating layer 22 is made of a suitable steel material such as a chromium molybdenum steel material having excellent mechanical strength, and is subjected to appropriate cutting and grinding to form a predetermined shape of the surface of the needle bar body 21 as a main body. Of PVD (Physical Vapor Dep.)
osition), and is formed by coating with a coating of carbide and carbon having a hardness of about Hv1000. The coating layer 22 may be formed on at least a portion of the surface of the needle bar main body 21 that comes into contact with the needle bar metal 15. That is, in the present embodiment, the needle bar main body 21 as a component forming the coating layer 22 is formed of a steel material, and at least the sliding surface 11a of the surface of the needle bar main body 21 is coated with carbide carbon. Layer 2
2 coated.

The thickness of the coating layer 12 is 0.5
It is about 10.0 μm, preferably about 0.5-5.0 μm, and most preferably about 0.5-4.0 μm. When the thickness is smaller than this range, almost no effect is obtained, and when the thickness is larger, the adhesiveness tends to decrease. Thus, by setting the film thickness of the coating layer 12 to about 0.5 to 4.0 μm, it is possible to obtain the most preferable thickness necessary for maintaining a stable function without lubrication for a long time. .

Further, as a film structure of the coating layer 12, as shown in an exaggerated manner in FIG. 4, the surface has a layered film structure and the carbide-rich layer 22a and the carbon-rich layer 22a.
The point that b and b are alternately arranged in a direction perpendicular to the film thickness direction exhibits a function of absorbing the load and impact load by the carbide rich layer 22a, and large load resistance can be easily obtained. Is preferred.

The needle bar body 21 is configured such that the surface of a steel material having excellent mechanical strength is covered with an intermediate film (not shown) made of chromium or nickel alloy, and then a coating layer 22 is formed. By increasing the hardness of the surface of the needle bar main body 21, it is possible to prevent the surface of the needle bar 11 from being damaged, to improve the corrosion resistance, and to separate the coating layer 22 from the needle bar main body 21. This is preferable in that it is possible to prevent the above.

When chromium is used as the intermediate film, the thickness of the intermediate film is about 1 to 10 μm, preferably about 2 to 6 μm, and most preferably about 2 to 4 μm. When the thickness is smaller than this range, the effect of preventing the surface of the needle bar main body 21 from being damaged tends to be small, and when the thickness is large, the surface tends to be easily peeled. By setting the thickness of the intermediate film made of chromium to about 2 to 4 μm,
The most preferable thickness required for preventing the surface of the needle bar main body 21 from being scratched, improving the corrosion resistance, and preventing the coating layer 22 from peeling off from the needle bar main body 21. Can be obtained.

When a nickel alloy is used as the intermediate film, the thickness of the intermediate film is about 1 to 15 μm, preferably about 5 to 12 μm, and most preferably 7 to 10 μm.
m. If the thickness is smaller than this range, the effect of preventing the surface of the needle bar main body 21 from being damaged tends to be small,
When it is thick, it tends to peel off. in this way,
By setting the thickness of the intermediate film made of a nickel alloy to about 7 to 10 μm, it is possible to reliably prevent the surface of the needle bar main body 21 from being damaged, to improve corrosion resistance, and to further improve the needle bar main body 21. The most preferable thickness required for preventing the coating layer 22 from peeling off can be obtained.

As the nickel alloy, nickel phosphorus (Ni-P), nickel boron or the like can be used. Furthermore, it is preferable that the intermediate film made of a nickel alloy be formed on the surface of the base material by chemical plating, that is, electroless plating, in order to obtain a dense and uniform film thickness with almost no pinholes.

The material of the needle bar body 21 is as follows.
A configuration using aluminum or aluminum alloy which is lighter than steel may be used. Such a configuration is preferable in that the needle bar 11 can be easily reduced in weight and the vibration damping property can be improved. When aluminum or an aluminum alloy is used as the material of the needle bar main body 21, the surface is covered with an intermediate film of chromium or nickel alloy, and then the coating layer 22 is formed. The surface of the needle bar body 21 made of a soft material is prevented from being damaged and deformed by increasing the hardness of the surface of the needle bar body 21 to strengthen the surface of aluminum or an aluminum alloy which is the base material of the needle bar body 21. This is preferable in that the coating layer 22 can be prevented from peeling off from the needle bar main body 21 as well as the needle bar main body 21.

When chromium is used as the intermediate film, the thickness of the intermediate film is about 1 to 10 μm, preferably about 2 to 6 μm, and most preferably about 2 to 4 μm. When the thickness is smaller than this range, the effect of strengthening the surface of the needle bar body 21 made of aluminum or aluminum alloy as a base material and preventing the surface of the needle bar body 21 from being damaged tends to be small, and when the thickness is large, the needle bar body 21 is easily peeled. Tend. Thus, the thickness of the intermediate film made of chromium is 2
By setting the thickness to about 4 μm, damage and deformation of the surface of the needle bar main body 21 can be reliably prevented, and the most preferable thickness necessary for preventing the coating layer 22 from peeling off from the needle bar main body 21. You can get it.

When a nickel alloy is used as the intermediate film, the thickness of the intermediate film is about 1 to 15 μm, preferably about 5 to 12 μm, and most preferably 7 to 10 μm.
m. If the thickness is smaller than this range, the needle bar body 21 made of aluminum or aluminum alloy as the base material
There is a tendency that the effect of preventing the surface of the needle bar body 21 from being damaged by strengthening the surface of the needle bar 21 is small. As described above, by setting the thickness of the intermediate film made of the nickel alloy to about 7 to 10 μm, it is possible to reliably prevent the surface of the needle bar main body 21 from being damaged and deformed, and to form the coating layer from the needle bar main body 21. The most preferred thickness required to prevent the 22 from peeling off can be obtained.

As the nickel alloy, nickel phosphorus (Ni-P), nickel boron or the like can be used. Furthermore, it is preferable that the intermediate film made of a nickel alloy be formed on the surface of the base material by chemical plating, that is, electroless plating, in order to obtain a dense and uniform film thickness with almost no pinholes.

That is, the intermediate film prevents the surface from being damaged or deformed by increasing the hardness of the surface of the base material which is the main body forming the coating layer 22, and also prevents the peeling of the coating layer 22 from the base material surface. This is particularly effective when the base material is a soft material such as aluminum.

A well-known needle pin 16 is fixed to the lower end of the needle bar 11 shown in FIG.

The needle bar metal 15 of the present embodiment is formed in a substantially cylindrical shape, and most of the inner peripheral surface of the needle bar metal 15 can reciprocate on the sliding surface 11a of the needle bar 11. The sliding surface 15a is supported. The needle bar metal 15 is made of brass, high-strength brass, bronze, phosphor bronze, aluminum bronze, lead bronze alloys and alloy castings in the sense that wear during sliding is reduced and the wear resistance is positively affected. , Aluminum alloys and alloy castings for bearings, alloys and alloy castings containing tin, zinc, and lead as main components can be used alone or in combination. However, at least the sliding surface 15a should be a lead-bronze alloy or alloy casting. Is preferable in that the wear resistance and durability during sliding in a non-lubricated state can be improved.

The needle bar metal 15 has a configuration in which at least only the portion forming the sliding surface 15a is formed of a lead-bronze-based alloy or alloy casting, and the other portions are formed of a low-cost metal material. Is also good.

Other configurations are the same as those of the conventional sewing machine, and the detailed description thereof will be omitted.

Next, the operation of the present embodiment having the above-described configuration will be described.

According to the sewing machine M of this embodiment, the needle bar 11
Is formed by a coating layer 22 of a thin film made of carbide and carbon. This coating layer 22
It has a structure in which carbide crystals are embedded in an amorphous carbon lattice, and a carbide-rich layer and a carbon-rich layer whose surfaces have excellent sliding action and load resistance are alternately arranged.

Therefore, the sliding surface 15 of the needle bar metal 15 has a low coefficient of friction, a self-lubricating property, a large load resistance, an abrasion resistance and an adhesive property, and is in contact with a supporting part.
The phenomenon of polishing a does not occur.

For example, the coating layer 22 made of carbide and carbon has excellent characteristics such that the coefficient of friction is about 0.1 to 0.2, the hardness of the film is about Hv1000, and the adhesion of the film is about 4000 MPa at the maximum. ing.

Further, using a test piece on which the carbide / carbon film of the present invention and the conventional DLC film were applied, under the same test conditions as in a non-lubricated environment, and the material of the mating member as the supporting member was phosphor bronze. When the coefficient of friction and the rise temperature (heat generation temperature) were determined, the coefficient of friction of the carbide-carbon film of the present invention was 0.227, and the rise temperature was 58 ° C. On the other hand, the friction coefficient of the conventional DLC film was 0.340, and the temperature rise was 78 ° C. As is clear from the results of the abrasion test, the carbide / carbon coating has excellent characteristics suitable for the sliding portion of the sewing machine in a non-lubricated state in which both the coefficient of friction and the rising temperature are lower than those of the conventional DLC coating. are doing.

That is, since the sliding surface 11a of the needle bar 11 of the present embodiment is formed by the coating layer 22 made of carbide and carbon, the coating layer has a low coefficient of friction, a self-lubricating property, and a large load resistance. With adhesiveness and adhesion, and
It has excellent characteristics that the phenomenon of polishing the other sliding surface that comes into contact does not occur and that it is hardly worn.

As described above, according to the needle bar 11 of the sliding device 10 for the sewing machine M according to the present embodiment, the coating layer 22 made of carbide and carbon forming the sliding surface 11a is provided.
It has a low coefficient of friction, self-lubricating property, large load resistance and adhesion, and does not cause the phenomenon of polishing the other sliding surface that comes in contact with it. Can be held.

Further, according to the needle bar 11 of the sliding device 10 for a sewing machine M of the present embodiment, the coating layer 22 is formed of PVD.
Since the temperature at the time of forming the coating layer 22 can be set to 250 ° C. or less, the coating layer 2
When forming the needle bar 2, the needle bar main body 21 can be reliably prevented from being thermally deformed and its hardness lowered, and the coating layer 2 can be formed.
2 can be formed efficiently, reliably and stably.

Further, according to the needle bar 11 of the sliding device 10 for the sewing machine M of the present embodiment, the needle bar body 21 is made of steel, so that the needle bar 11 has excellent mechanical strength. be able to. Therefore, by forming the main body from a steel material, a sliding component or a supporting component requiring high strength can be easily obtained.

According to the sliding device 10 for a sewing machine M of the present embodiment, the sliding surface 11a of the needle bar 11 and the sliding surface 15a of the needle bar metal 15 supporting the needle bar 11 are provided. It is possible to easily obtain the most suitable combination that can surely prevent wear and seizure damage of a sliding portion for a long period without lubrication. That is, it is possible to easily realize lubrication-free sliding parts.

According to the sewing machine M of this embodiment,
Since there is no need to provide an oiling mechanism, lubricating oil does not leak from the sliding portion between the needle bar metal 15 and the needle bar 11 to the outside of the sewing machine body 12 to contaminate the sewing product, and the structure is simplified, In addition, since the number of parts, the number of assembly steps, and the like can be reduced, the cost can be reduced.

Further, according to the sewing machine M of the present embodiment,
Since the wear between the needle bar metal 15 and the needle bar 11 does not occur due to the sliding, the sewing object placed under the needle bar 11 is not stained.

The sewing machine M of the present embodiment includes a sliding surface 11a of the needle bar 11 constituting the sliding device 10 for the sewing machine.
And the sliding surface 1 of the needle bar metal 15 supporting the needle bar 11
A configuration may be adopted in which grease is interposed between the grease and 5a.
With such a configuration, the durability of the sliding portion in the oil-free state can be further improved.

The sliding device 10 for a sewing machine according to this embodiment
In the configuration of both the sliding surface 11a of the needle bar 11 and the sliding surface 15a of each needle bar metal 15,
Or the sliding surface 15 of each needle bar metal 15
Only a may be used as the coating layer 22. Even with such a configuration, the same effects as those of the above-described sliding device for sewing machine 10 can be obtained.

The sliding device for a sewing machine according to the present invention includes:
At least one of the sliding surface of the reciprocating shaft such as the presser bar and the sliding surface of the bearing metal supporting the reciprocating shaft
A configuration in which at least one of the sliding surface of the upper looper hugging and the upper looper hugging metal that supports the upper looper hugging is formed by a coating layer made of carbide and carbon; A configuration in which at least one of the sliding surface of the bridge and the slidable surface of the guide groove of the square bridge guide that supports this square bridge is formed by a coating layer made of carbide and carbon, and an upper shaft that performs a rotary motion, a lower shaft, A configuration in which at least one of a sliding surface of a rotating shaft such as a shaft, a needle swing shaft, and a vertical axis and a sliding surface of a bearing metal supporting the rotating shaft is formed of a coating layer made of carbide and carbon; At least one of a rocking shaft such as a balance support shaft, a needle bar rocking shaft, and a needle feed shaft which performs a dynamic motion, and a sliding surface of a bearing metal supporting the rocking shaft is made of carbide carbon. By shape Configuration may be alone or in combination with that.

Further, the present invention can be applied to sliding portions of various moving parts such as a feed cam of an operation feed mechanism and a looper thread balance.

The present invention can be used not only for sewing machines that operate at high speed, such as lock sewing machines, but also for general sewing machines such as household sewing machines.

The present invention is not limited to the above embodiment, but can be variously modified as needed. For example, the sliding device for a sewing machine of the present invention may be used for a sewing machine having a conventional oil supply mechanism.

[0072]

As described above, according to the sliding device for a sewing machine according to the first aspect of the present invention, the coating layer has a low coefficient of friction, a self-lubricating property, a large load resistance and an adhesive property.
In addition, since the phenomenon of polishing the sliding surface of the contacting supporting component does not occur, an extremely excellent effect such as maintaining a stable function without lubrication for a long time is exhibited.

According to the sliding device for a sewing machine according to the second aspect of the present invention, the coating layer can be efficiently and reliably formed, and the processing temperature at the time of forming the coating layer can be reduced to two.
Since it can be carried out at a low temperature of about 50 ° C., an extremely excellent effect such as hardly affecting the hardness of the main body to be coated with the coating layer or the like is exerted.

According to the sliding device for a sewing machine according to the third aspect of the present invention, the carbide-rich layer can absorb a load, so that a large load resistance can be easily obtained. It has an extremely excellent effect.

According to the sliding device for a sewing machine of the present invention according to the fourth aspect, it is possible to obtain the most preferable thickness necessary for maintaining a stable function without lubrication for a long period of time. It has an extremely excellent effect.

According to the sliding device for a sewing machine of the present invention, since the main body has excellent mechanical strength,
An extremely excellent effect is obtained such that a sliding component or a supporting component requiring high strength can be easily obtained.

According to the sliding device for a sewing machine according to the present invention, the intermediate film made of chromium, which covers the surface of the main body made of steel, increases the hardness of the surface of the main body, thereby increasing the hardness of the main body. It is possible to prevent surface damage, improve corrosion resistance, and prevent the coating layer from peeling off from the main body.

According to the sliding device for a sewing machine of the present invention, the intermediate film made of chromium covering the surface of the main body made of aluminum or aluminum alloy is
By increasing the hardness of the surface of the main body, it is possible to prevent the surface of the main body formed of a soft material from being damaged and deformed, and to prevent the coating layer from being peeled off from the main body, which is extremely excellent. It has the effect.

According to the sliding device for a sewing machine according to the present invention, the intermediate film made of chromium having a thickness of 2 to 4 μm can damage the surface of the main body and peel off the coating layer from the main body. And an extremely excellent effect such as that can be more reliably prevented.

According to the sewing machine of the ninth aspect, the intermediate film made of a nickel alloy that covers the surface of the main body made of a steel material can increase the hardness of the surface of the main body, thereby damaging the surface of the main body. , The corrosion resistance can be improved, and the coating layer can be prevented from peeling off from the main body.

Further, according to the sewing machine of the present invention, the intermediate film made of nickel or a nickel alloy covering the surface of the main body made of aluminum or aluminum alloy is made of a soft material by increasing the hardness of the surface of the main body. Thus, it is possible to prevent the surface of the main body formed from being damaged and deformed, and to prevent the coating layer from peeling off from the main body.

According to the sewing machine of the present invention, the intermediate film made of a nickel alloy having a thickness of 7 to 10 μm can more reliably prevent the surface of the main body from being damaged and the coating layer from the main body from peeling off. It has an extremely excellent effect that it can be prevented.

According to the sewing machine of the twelfth aspect of the present invention, an extremely excellent effect is obtained such that oil-free lubrication of the sliding portion can be easily realized.

Further, according to the sewing machine of the thirteenth aspect of the present invention, an extremely excellent effect is obtained such that the durability of the sliding portion in the oil-free state can be further improved.

[Brief description of the drawings]

FIG. 1 is a front view of a main part of an embodiment of a sewing machine according to the present invention using a sliding device for a sewing machine according to the present invention.

FIG. 2 is a partially cut front view of a main part of the sliding device for the sewing machine of FIG. 1;

FIG. 3 is an enlarged sectional view taken along line 3-3 in FIG. 2;

FIG. 4 is a schematic view illustrating the structure of a coating layer in FIG. 2;

[Explanation of symbols]

 Reference Signs List 10 Sliding device for sewing machine 11 Needle bar 11a Sliding surface 15 Needle bar metal 15a Sliding surface 21 Needle bar body 22 Coating layer 22a Carbide rich layer 22b Carbon rich layer M sewing machine

Claims (13)

[Claims] 1. A sliding device for a sewing machine, wherein a sliding surface of a movable sliding component is supported by a sliding surface of a supporting component, wherein the sliding surface of the sliding component and the sliding surface of the supporting component slide. A sliding device for a sewing machine, wherein at least one of the surfaces is formed by a coating layer made of carbide and carbon. 2. The sliding device for a sewing machine according to claim 1, wherein the coating layer is formed by PVD. 3. The sewing machine according to claim 1, wherein the coating layer has a layered film structure, and a carbide-rich layer and a carbon-rich layer are alternately arranged. For sliding devices. 4. The coating layer has a thickness of 0.5 to 4.0 μm.
The sliding device for a sewing machine according to any one of claims 1 to 3, wherein: 5. The sliding device for a sewing machine according to claim 1, wherein a main body of a component forming the coating layer is formed of a steel material. 6. The method according to claim 1, wherein the body of the component forming the coating layer is formed by covering the surface of a steel material with an intermediate film made of chromium. A sliding device for a sewing machine as described in the above. 7. The component according to claim 1, wherein the body of the component forming the coating layer is formed by covering the surface of aluminum or an aluminum alloy with an intermediate film made of chromium. 2. The sliding device for a sewing machine according to claim 1. 8. The sliding device for a sewing machine according to claim 6, wherein the intermediate film has a thickness of 2 to 4 μm. 9. The component according to claim 1, wherein a body of the component forming the coating layer is formed by covering a surface of a steel material with an intermediate film made of a nickel alloy. 3. The sliding device for a sewing machine according to claim 1. 10. The device according to claim 1, wherein the body of the component forming the coating layer is formed by covering the surface of aluminum or an aluminum alloy with an intermediate film made of a nickel alloy. The sliding device for a sewing machine according to claim 1. 11. The sliding device for a sewing machine according to claim 9, wherein the intermediate film has a thickness of 7 to 10 μm. 12. A sewing machine having a sliding device for a sewing machine that supports a sliding surface of a movable sliding component on a sliding surface of a supporting component, wherein the sliding device for the sewing machine is provided. A sewing machine, which is the sliding device for a sewing machine according to any one of claims 11 to 11. 13. The sewing machine according to claim 12, wherein grease is interposed between the sliding surface and the slidable surface.