JP3014021B2 - Oil-free full-rotary kettle of industrial sewing machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a non-lubricating full-rotation kettle of an industrial sewing machine provided in a lockstitch sewing machine or the like.

[0002]

2. Description of the Related Art An inner hook provided in a lockstitch sewing machine or the like includes:
A rail is formed on the outer peripheral surface, and this rail is fitted into a rail groove formed on the inner peripheral surface of the outer hook, and the inner hook is fixed to the machine body of the sewing machine. With the rotation to the downstream side blocked, only the outer kettle is rotationally driven at high speed. In particular, the outer hook of the industrial sewing machine is driven to rotate at a high speed of about 6,000 to 10,000 rpm. Therefore, a large frictional force is generated by sliding contact between the rail and the groove, and a large torque is required for rotation of the outer hook. If the friction between the rail and the groove is large, the inner surface of the inner bite recess that the bite member fits into the bite member that prevents rotation of the inner bite contacts with a large force. The thread cannot be pulled out smoothly, which undesirably changes the tension of the upper thread, lowers the quality of sewing, and reduces friction due to friction between the rails and the grooves. Problem.

[0003] In order to solve this problem, it is well known that lubricating oil is supplied between a surface layer, which is the outer peripheral surface of the inner rail, and the inner peripheral surface of the outer rail groove. , Lower thread and cloth may be stained by the lubricating oil.

Therefore, conventionally, there is also a configuration in which the inner rail portion is coated with a fluorine resin having a low coefficient of friction, such as Teflon (trade name).

[0005]

In the prior art as described above, when coating with a fluorine resin or the like, this is sprayed and fired, and the film thickness is usually 10 to 20 μm.
Since it is as thin as possible, the durability is low, and there is a problem that it is immediately peeled off, especially when no lubrication is used.

SUMMARY OF THE INVENTION An object of the present invention is to make it possible to rotate the outer hook smoothly, stably and at a high speed without lubrication and by minimizing the friction in the sliding portion between the inner hook and the outer hook. It is an object of the present invention to provide a lubrication-free full-rotation kettle of an industrial sewing machine.

[0007]

According to the present invention, there are provided 6000 to 1
In an inner lug of an industrial sewing machine, in which a rail of an inner hook is fitted into a rail groove of a steel outer hook of 0000 rpm, a rail portion of a steel inner hook main body is connected to a thread portion of the rail portion. The covering member is integrally formed over the thread pull-out portion to form a rail, and the covering member is required for rotational driving of the outer hook when industrial sewing machine oil is interposed between the outer hook and the inner peripheral surface of the outer track groove. It is made of synthetic resin whose torque is larger than the torque when the industrial sewing machine oil is not interposed,
The synthetic resin is an aromatic polyimide resin, and is within an oil-free full-rotation kettle of an industrial sewing machine.

Further, according to the present invention, the thickness t of the covering member is set to 0.1.
It is 3 to 0.5 mm.

Further, the present invention is characterized in that grooves 20 are formed on both sides of the rail portion 16, respectively, and the covering member fits into the grooves 20.

Further, the present invention is characterized in that a plurality of small holes 38 extending in the thickness direction of the rail portion 36 are formed in the rail portion 36 at intervals in the circumferential direction, and the small hole 38 is filled with a covering member. I do.

[0011]

According to the present invention, 6,000 to 10,000 rpm
In the inner hook of an oil-free full-turn hook of an industrial sewing machine in which the inner hook rail fits into the steel outer hook rail groove, the thread from the thread splitting section of this The torque required for the rotary drive of the outer kettle when the industrial sewing machine oil is interposed between the outer periphery and the inner peripheral surface of the outer groove is greater than the torque required when the industrial sewing machine oil is not interposed. Since the rail is formed by integrally molding a covering member made of an aromatic polyimide resin, which is a synthetic resin that becomes larger, there is no need to supply industrial sewing machine oil to the rail and the track groove, and therefore, such as industrial sewing machine oil, etc. It is possible to prevent the upper and lower threads and the cloth to be sewn from being stained by the lubricating oil.

Further, according to the present invention, the thickness t of the covering member
Is 0.3 to 0.5 mm, the covering member has a sufficient thickness, and the durability is improved. At this time, since a part of the covering member fits into the groove formed in the rail portion, Detachment is prevented.

Further, according to the present invention, since the covering member fits into the grooves formed on both sides of the rail portion, a part of the covering member fits into the groove formed in the rail portion and may come off. Is prevented.

Further, according to the present invention, a plurality of elevations extending in the thickness direction of the rail portion at intervals in the circumferential direction are formed in the rail portion, and the small holes are filled with the coating member. The displacement can be prevented.

[0015]

FIG. 1 is a horizontal full rotation kettle 1 according to an embodiment of the present invention.
FIG. 2 is a front view showing a partly cutaway view, and FIG. An inner furnace 4 is mounted on the outer furnace 3 having the rotating shaft 2, and a rail 5 formed on an outer peripheral surface of the inner furnace 4 is fitted into a rail groove 6 formed on an inner peripheral surface of the outer furnace 3. Fit. A bobbin 8 around which a bobbin thread is wound is housed in the recess 7 of the inner hook 4. The center hole 9 of this bobbin 8
, A cylindrical stud 11 protruding from the bottom 10 of the inner kettle 4 toward the open end of the inner kettle 4 is inserted. At the end of the stud 11, a holding piece 12 that is stable at two positions, that is, a state where it is extended in the axial direction and a state where it is angularly displaced in the radial direction, is provided so as to be angularly displaceable, and this holding piece 12 is shown in FIG. When the bobbin 8 is housed in the recess 7 of the inner kettle 4 and is tilted down so as to extend in the radial direction of the inner kettle 4 to be in a stable state, the bobbin 8 in the recess 7 is prevented from coming off. ,
Further, the bobbin 8 can be detached from the inner hook 4 by setting the presser piece 12 to be in an upright state along the longitudinal direction of the stud 11.

A contact portion 13 projecting outward in the radial direction is formed on the inner hook 4, and an inner hook detent member (not shown) comes into contact with the contact portion 13 so that the inner hook 4 rotates with the rotation of the outer hook.
Is prevented, and in this state, the outer furnace 3 is driven to rotate about the rotation axis L1. The outer bite 3 has a sword tip 14
The needle thread caught by the point 14 moves in the direction indicated by the arrow 15 and
The thread is passed over the outer peripheral surface of the bobbin, and is engaged with the lower thread pulled out from the bobbin 8 so that a seam can be continuously formed on the workpiece.

FIG. 3 is a rear view of the inner kettle 4 of the horizontal full rotation kettle 1. The inner hook 4 includes an inner hook main body 4a and a rail 5 formed on the outer peripheral surface of the inner hook main body 4a.
Are divided in the circumferential direction. The rail 5 is composed of a rail portion 16 and a covering member 17. In the thread dividing portion 18, the rail portion 16 is exposed from the covering member 17 toward the upstream side in the rotation direction Y of the outer kettle 3. A groove 20 is formed in the rail portion 16.
A part of the covering member 17 is fitted into the cover member.

FIG. 4 is an enlarged sectional view taken along the line AA of FIG. The inner furnace body 4a and the rail portion 16 are made of steel, and a coating member 17 made of a liquid crystal polymer is integrally formed on the outer surface 16a of the rail portion 16 with a thickness t selected to be 0.3 to 0.5 mm. It is formed by molding, for example, outsert. Since the covering member 17 is formed with a sufficient thickness in this way, the durability is improved, and at this time, a part of the covering member 17 fits into the groove 20 formed in the rail portion 16 so that the covering member 17 comes off. Is prevented.

The covering member 17 is made of an aromatic polyimide resin or a liquid crystal polymer. The liquid crystal polymer used for the covering member 17 will be described in detail. The liquid crystal polymer having a rod-shaped rigid component in the main chain of the polymer has a large intermolecular force between the rigid linear components and is well oriented and crystallized at the time of molding. Even if the temperature rises due to friction caused by the outer basket 3 that is driven to rotate at a high speed, the heat deformation temperature is extremely high, so that there is no deformation. In addition, the liquid crystal polymer is composed of rigid molecular chains, and has a high strength and a high elastic modulus because it is highly oriented in the flow direction at the time of molding, and the molecular chains are arranged in an extended state in the orientation direction. Therefore, it exhibits excellent creep characteristics that hardly elongates even when a tensile force is applied. The coefficient of linear expansion is extremely small, and particularly, the coefficient of linear expansion in the flow direction is about 1 × 10 ⁻⁵ cm / cm / ° C. Such a linear expansion coefficient is one digit lower than other synthetic resins, and it is possible to obtain dimensional stability equivalent to that of metal.
From this, the dimensional change due to environmental temperature difference and humidity difference between summer and winter is almost zero. In addition, the liquid crystal polymer has high weather resistance, so that it can be used for a long time. Further, the liquid crystal polymer has a slight phase change because the structures in the molten state and the solidified state are similar, and the volume change upon solidification is also small.

A very interesting characteristic of the liquid crystal polymer is a characteristic of damping vibration. In general, soft materials such as rubber are excellent in damping vibration,
The liquid crystal polymer has high vibration damping characteristics while having a high elastic modulus. In order to improve abrasion resistance, 30% of carbon fiber may be mixed with the liquid crystal polymer in order to reduce the specific abrasion amount and the dynamic friction coefficient. The liquid crystal polymer comprises a copolymer of parahydroxybenzoic acid and 2-hydroxy-6-naphthoic acid. As another material, two or three or more kinds of naphthalene groups may be used as one constituent component of the main chain bond, and may be a copolymer with another constituent component. The naphthalene group,
1.2, 1.4, 1.5, 1.8, 2.3,
It is a compound having a functional group at two or more substitution positions selected from the 2.6 position and the 2.7 position, and the functional group may be a functional group capable of forming a polyester and / or a polyesteramide. That is, the functional group is selected from a hydroxy group, a carboxyl group, an amino group, an ester group, and the like.

The naphthalene group may be hydroxynaphthoic acid, dihydroxynaphthalene and / or naphthalenedicarboxylic acid.

Constituents other than the naphthalene group include a phenyl group at the p-position, a 4,4'-biphenyl group and / or a compound represented by the general formula:

[0023]

Embedded image

(Where X is an alkylene (C 1 -C 1)
4) alkylidene (C 1-4), -O-, -S-,
_{-SO -, - SO 2 -,} - CO- than group selected, R,
R 'is a reactive group such as a hydroxy group or a carboxyl group or an ester thereof. ) And substituted derivatives thereof. The bonding unit of the polymer is preferably an ester and / or an ester amide, and the functional group forming them is selected from a hydroxy group, a carboxyl group, an amino group, an ester group and the like, and more preferably terephthalic acid, hydroquinone, p-diacetoxy. Phenylene, p-hydroxybenzoic acid and esters thereof, 4,4'-dihydroxybiphenyl,
4,4'-dicarboxybiphenyl, 4-hydroxy-
4'-carboxybiphenyl and esters thereof, wherein X in the general formula of Formula 1 is methylene, propenyl or-
Each dihydroxy form, dicarboxyl form, which is SO ₂ —
Hydroxycarboxy forms and their esters are selected, and more preferably terephthalic acid, hydroxybenzoic acid, 4,4'-dihydroxybiphenyl, 4,4 '
-Dicarboxybiphenyl and their esters are selected.

FIG. 5 is a cross-sectional view of a part of an injection molded product 28 of a liquid crystal polymer. The liquid crystal polymer includes an outer skin layer 29 in which molecular chains are highly oriented in the flow direction, an inner skin layer 30, and a core layer 31 whose orientation is not clear. The thickness of the skin layers 29, 30 is substantially constant at 0.3 to 0.2 mm regardless of the thickness of the molded product. The liquid crystal polymer is plasticized by heating, pressed into a closed mold, cooled and solidified, and then opened and taken out. As described above, since the coating member can be manufactured by molding the liquid crystal polymer into a mold, the processing is easy and the productivity is improved.

The polymer of the liquid crystal layer is composed of the respective skin layers 29, 3
Since 0 is strongly oriented in the flow direction, it has excellent mechanical properties of high strength and high elastic modulus. However, since anisotropy is likely to occur due to easy orientation, it is preferable to introduce a reinforcing agent into the rigid skeleton to reduce this anisotropy. In addition, since it is easy to orient, fibrils separated from the skin layers 29 and 30 are easily generated. Macro fibril 32 is 5
μm, fibril 33 is 0.5 μm, and microfibril 27 is 0.05 μm. The liquid crystal polymer has a multilayer structure including the outer skin layer 29, the inner skin layer 30, the core layer 31, and the like, and exhibits a large vibration damping characteristic despite its high elastic modulus.

The covering member 1 made of such a liquid crystal polymer
Even when sewing is performed at high speed for a long period of time using the inner hook 4 on which the rail 5 having the rail 7 is formed, the surface of the rail 5 requires very little abrasion, and the thread dividing portion 18 which is a portion through which the thread passes. Since the steel rail portion 16 is exposed from the covering member 17, the so-called thread path can be prevented.

FIG. 6 is a rear view of an inner hook 34 according to another embodiment of the present invention. The inner hook 34 generally includes an inner hook main body 34a and a rail 35 formed on the outer peripheral surface of the inner hook main body 34a. It has been formed. The rail 35 is composed of a rail portion 36 and a covering member 37. In the thread dividing portion 18, the rail portion 36 is exposed from the covering member 37 toward the upstream side in the rotation direction Y of the outer kettle 3. A small hole 38 having a diameter of about 1.0 mm is formed in the rail portion 36 at an angle θ =
Five or six rail portions 36 are formed at intervals of about 50 °, and the small holes 38 are filled with a liquid crystal polymer.

FIG. 7 is an enlarged sectional view taken along line BB of FIG. 6, and FIG. 8 is an enlarged sectional view taken along line CC of FIG. The inner bite body 34a and the rail portion 36 having the small hole 38 are made of steel.
A coating member 37 made of a liquid crystal polymer is integrally formed on the outer surface 36a of the liquid crystal panel with a thickness t selected to be 0.3 to 0.5 mm. At this time, a part of the liquid crystal polymer penetrates and fills the small holes 38. You. The portion where the small hole 38 is not provided is
As shown in FIG. 8, the covering member 37 having the thickness t and the rail portion 3
6, a rail 35 is formed. By providing the small holes 38 in the rail portion 36 and filling the small holes 38 with the liquid crystal polymer, the displacement of the covering member 37 can be further prevented.

FIG. 9 is a cross-sectional view of an inner kettle 44 of a vertical full rotation kettle according to another embodiment of the present invention. The inner hook 44 has a cylindrical portion 46 on which a rail 45 is formed on the outer peripheral surface, and a bridge 47 which is continuous with one axial end of the cylindrical portion 46 in a direction perpendicular to the rail,
The bridge 47 has a stud 48 erected toward the open end of the inner hook 44. A flange 49 extending radially outward is formed at an end of the inner hook 44 on the open end side.
The rail 45 is composed of a rail portion 50 and a covering member 51, and has a configuration similar to that of FIG.

In the above embodiment, the covering members 17, 37,
Although 51 is not formed in the thread dividing portion 18,
As another embodiment of the present invention, such a covering member may be formed so as to cover the thread splitting portion. In still another embodiment, the coating member covers not only the thread splitting portion but also the thread pull-out portion. It may be configured as follows.

FIG. 10 is a perspective view of an inner kettle 71 used for a vertical full rotation kettle according to one embodiment of the present invention. The inner hook 71 basically has an inner hook main body 72 and a rail member 74 fitted and fixed in a fitting groove 73 formed on the outer peripheral portion of the inner hook main body 72. The inner bite body 72 includes a cylindrical portion 75, a flange portion 77 having an inner bite-stop recess 76 formed at an end of the cylindrical portion 75, and a cylindrical portion 75.
And a bottom portion 78 formed at an end of the bottom portion.

FIG. 11 is a sectional view of the vicinity of the fitting groove 73. A rail member 74 is fitted into the fitting groove 73. The rail member 74 has a rail 79 and a fitting projection 80 protruding radially inward. A plurality of fitting projections 80 are formed integrally with the rail 79 at intervals in the circumferential direction.
The rail 79 is fitted into a rail groove 83 of an outer hook 82 described later, and the outer hook 82 is driven to rotate at a high speed.

FIG. 12 is a perspective view showing an assembled state of the inner kettle 71. As shown in FIG. The rail member 7 is provided in the inner bite main body 72.
4 are fitted and fixed. Such an inner hook 71 is attached to an outer hook 82, a bobbin case is attached to the inner hook 71, and a detent protrusion fixed to the machine body of the sewing machine fits into a detent recess 76 of the inner hook 71. When the outer hook 82 is driven to rotate as indicated by an arrow 86, the inner hook 71 is prevented from rotating. The rotation axis of the outer kettle 82 has a horizontal axis and constitutes a vertical full rotation kettle.

The rail member 74 is made of a material which is a liquid crystal polymer which is a synthetic resin. The endless annular rail 79 has a resilient force, and the rail of the rail member 74 is moved by the resilient force. It can be pushed into the bottom 78 of 71 as shown at 89 in FIG. At this time, the fitting projections 80 are fitted elastically exactly into the circumferentially extending mounting recesses 91 formed in the fitting grooves 73 of the inner kettle body 72, and thus the rails 79 are attached to and detached from the inner kettle body 72. Fixed as possible. The inner shape of the mounting recess 91 is the fitting protrusion 8.
0, and the fitting projection 80 is fitted and fixed to the mounting recess 91 as described above. Further, an adhesive may be used to detachably fix the rail 79 to the inner pot main body 72.

In the present invention, the friction coefficient between the rail and the groove is reduced by reducing the friction coefficient between the rail and the groove by forming at least the surface layer of the inner rail as a liquid crystal polymer or an aromatic polyimide resin as in the above-described embodiments. Thus, the object of the present invention that the outer hook can be rotated can be achieved.
By using the liquid crystal polymer or the aromatic polyimide resin, the following three important effects a, b, and c can be achieved: (a) the outer basket can be rotationally driven with a small torque; The torque when the sewing machine oil is interposed between the surface layer of the rail and the inner peripheral surface of the outer groove is larger than the torque when the industrial sewing machine oil is not interposed, in other words, the liquid crystal polymer. When oil is not used, it is possible to reduce the torque by using no oil. (B) Even if oil is not used, the gap between the surface layer of the rail and the inner peripheral surface of the outer groove of the outer groove is obtained. The amount of increase in clearance is very small, and the amount of wear is other synthetic resin,
For example, it is sufficiently smaller than fluororesin such as Teflon (trade name), and therefore has extremely excellent durability. (C) The occurrence of thread balls and thread breakage when no lubrication is performed is much smaller than when lubrication is used. This achieves the effect that the quality of the sewn product is improved as compared with the case of a sewing machine that refuels because both the inner and outer hooks are made of steel.

The fact that at least the surface layer of the rail is made of a liquid crystal polymer reduces the coefficient of friction with the rail groove of the outer cage and enables the outer cage to be rotationally driven with a small torque. This is apparent from FIG.

Lines L1 and L2 in FIG. 13 correspond to the rail shown in FIGS. 10 to 12 in the drawings of the present application, in which the outer furnace main body 72 is made of steel and made of a fluorine resin which is Teflon (trade name). This shows the characteristics when using a sewing machine hook to which the member 74 is attached.

[0039]

[Table 1]

The rotation speed of the outer furnace 82 is 4000 to 700.
It is understood that it is impossible to use the fluorine resin without lubrication under the operating conditions of 0 rpm and high speed in the industrial sewing machine, as is apparent from the line L1. When the lubrication by the industrial sewing machine is performed by using the fluororesin as in the line L2, the torque for rotating the outer hook 82 is drastically reduced. However, when such an industrial sewing machine oil is used, the upper thread and the lower thread are used. A major problem arises in that the yarn, as well as the fabric, becomes fouled by the industrial sewing oil.

In a sewing machine using a conventional vertical full rotation kettle in which the inner and outer hooks are made of steel, a line L5 in FIG.
As shown by, even if lubrication with industrial sewing machine oil is performed, the torque required for rotational driving of the outer kettle 82 is too large,
The quality of sewing products is reduced.

Up to full vertical rotation according to the present invention, the inner kettle body 72 is made of steel, and the rail member 74 is made of liquid crystal polymer. Even when the sewing machine rotates at a high speed, the torque required for rotationally driving the outer hook 82 is smaller than the line L2 of the inner hook made of lubricated fluororesin, and is indicated by a steel line L5. It was confirmed that the size was sufficiently smaller than that of a conventional vertical full-rotation kettle having lubrication having characteristics.

In the above vertical full rotation kettle provided with such a rail member made of a liquid crystal polymer, when an industrial sewing machine oil is interposed between the surface layer of the rail and the inner peripheral surface of the rail groove of the outer cage, As shown by the line L4, it was confirmed that the torque required for the rotary drive of the outer hook was increased. Therefore, in the present invention, when at least the surface layer of the rail interposes a lubricant such as an industrial sewing machine oil such as a liquid crystal polymer, the torque required for the rotational drive of the outer hook 82 increases, and the industrial sewing machine oil intervenes. It is understood that it is important to be made of a synthetic resin having a characteristic that the torque when it is not driven is small, and it is understood that the torque can be sufficiently reduced by using no lubrication.

Since at least the surface layer of the rail is made of a liquid crystal polymer, the clearance between the surface layer of the rail member 74 and the inner peripheral surface of the outer groove is maintained substantially constant, and wear is reduced. It is clear from the experimental results of the present inventor of FIG. 14 that the number is extremely small.

[0045]

[Table 2]

In FIG. 14, the outer kettle 82 is made of steel, and a steel inner kettle body 72 is used. Line L1
3, L14 has a configuration in which a rail member 74 made of a liquid crystal polymer is fixed. In this FIG.
2 is 6,500 rpm. In the lines L11 and L12 in which the rail members are made of fluororesin, the amount of increase in the clearance increases rapidly in a relatively short time without lubrication, so that the lines L11 and L12 cannot be used as a vertical full rotation kettle. In the lines L13 and L14 showing characteristics when the rail member 74 is made of a liquid crystal polymer, the amount of increase in clearance is very small and stable even during the sewing operation of the sewing machine for a long time. The characteristics are similar to those when lubricating a conventional steel kettle as shown, that is, both the outer and inner kettles are made of steel. According to the present invention, it is possible to use the inner kettle in which the liquid crystal polymer is formed on at least the surface layer as shown by lines L13 and L14, so that even if no oil is supplied, the clearance increase amount is small and long. It can be seen that it is stable over time, so that the generation of noise is reduced, and the sewing performance is well maintained over a long period of time.

Further, by using the inner kettle having the rail member 74 at least whose surface layer is made of a liquid crystal polymer according to the present invention, as apparent from FIGS. It can be seen that the number of cut defects is reduced and the quality of sewing products is improved.

[0048]

[Table 3]

In particular, it can be seen that, in the configuration using the liquid crystal polymer, the quality of the sewn product is further improved by making the oil-free. 15 to 17, the rotation speed of the outer kettle 82 is 6000 rpm.

In FIGS. 15 to 17, the configuration of the inner kettle in which the surface layer of the rail is a liquid crystal polymer is the inner kettle body 72.
Are made of steel, and the rail member 74 is made of a liquid crystal polymer.
When the surface layer of the rail is made of steel, the entire inner hook is made of steel. In these experiments, the outer kettle is made of steel. The experiment using refueling is performed using industrial sewing machine oil. According to these experimental results, regardless of the change in the material and the count of the upper and lower yarns, the number of defective balls and broken yarns was reduced in the inner kettle using the liquid crystal polymer, especially when no lubrication was used. It can be seen that the number is reduced, indicating that the quality of the sewn product has been improved.

It can be seen that the effects a, b, and c described above are achieved by using at least the surface layer of the rail with a liquid crystal polymer.

In each of the embodiments shown in FIGS.
Experimental results similar to those in FIGS. 15 to 17 were obtained, and it was confirmed that the configuration of the present invention was excellent.

Further, when the same experiment as described above was conducted using a wholly aromatic polyimide resin instead of the liquid crystal polymer, similarly good results were obtained.

[0054]

According to the present invention, when the industrial sewing machine oil is interposed between the covering member and the inner peripheral surface of the outer groove, the torque required for the rotary driving of the outer hook is reduced by the industrial Since it is made of an aromatic polyimide resin which is a synthetic resin having a torque larger than that when no sewing machine oil is interposed, it can be made oil-free, and therefore, upper and lower threads, and cloths made of lubricating oil such as industrial sewing machine oil. Thus, an excellent effect of preventing contamination can be achieved.

As described above, since no lubrication is required, lubricating oil such as industrial sewing machine oil is not consumed, and it is not necessary to realize a configuration for supplying such lubricating oil. The configuration can be simplified,
Furthermore, maintenance can be facilitated.

Further, according to the present invention, since the thickness of the covering member is 0.3 to 0.5 mm, the covering member is formed with a sufficient thickness, and the durability is improved. Since it fits into the groove formed in the rail portion, it is prevented from coming off.

Further, according to the present invention, since the covering member fits into the groove formed on both sides of the rail portion 10, the covering member is prevented from coming off the groove.

Further, according to the present invention, a plurality of small holes extending in the thickness direction of the rail portion are formed in the rail portion at intervals in the circumferential direction, and the small hole is filled with the covering member. The covering member can be securely attached.

The invention can also be implemented in connection with a full horizontal rotary kettle or a full vertical rotary kettle.

As described above, according to the present invention, at least the surface layer of the rail is made of an aromatic polyimide resin, whereby friction between the surface layer and the inner peripheral surface of the rail groove can be reduced. The wear resistance can be improved, and the durability of the inner kettle can be improved. further,
The rotation speed of the outer kettle can be further improved.

[Brief description of the drawings]

FIG. 1 is a partially cutaway front view of a horizontal full rotation kettle 1 according to an embodiment of the present invention.

FIG. 2 is a plan view of the horizontal full rotation kettle 1;

FIG. 3 is a rear view of the inner rotary hook 4 of the horizontal full rotation rotary hook 1;

FIG. 4 is an enlarged cross-sectional view taken along line AA of FIG. 3;

FIG. 5 is a cross-sectional view of an injection molded product 28 of a liquid crystal polymer with a part cut away.

FIG. 6 is a rear view of an inner hook 34 according to another embodiment of the present invention.

FIG. 7 is an enlarged cross-sectional view taken along line BB of FIG. 6;

FIG. 8 is an enlarged cross-sectional view taken along line CC of FIG. 6;

FIG. 9 is a cross-sectional view of an inner rotary hook 44 of another embodiment of the present invention.

FIG. 10 is an exploded perspective view of an inner hook 71 according to another embodiment of the present invention.

11 is a cross-sectional view showing the vicinity of a fitting groove 73 of the inner hook 71. FIG.

FIG. 12 is a perspective view of an inner hook 71 of the above embodiment of the present invention.

FIG. 13 is a diagram showing experimental results by the inventor of the present invention for torque required for rotary driving of an outer hook between an embodiment of the present invention and a comparative example.

FIG. 14 is a diagram showing an increase in the operation time, ie, the sewing time, of the clearance, which is the gap between the surface layer of the rail and the inner peripheral surface of the rail groove of the outer hook, according to the embodiment of the present invention and the comparative example. It is a figure showing an experimental result of the inventor.

FIG. 15 is a diagram showing the experimental results of the present inventor showing the sewn product quality of one example of the present invention and a comparative example when Tetron # 50 is used as the upper thread and the lower thread.

FIG. 16: Polyester spun # as upper and lower threads
It is a graph which shows the experimental result of the present inventor which shows the sewn product quality of one Example of this invention and a comparative example when 60 is used.

FIG. 17 is a diagram showing the experimental results of the present inventor showing the sewn product quality of one example of the present invention and a comparative example when cotton yarn # 120 is used as the upper thread and the lower thread.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Horizontal full rotation hook 4,34,44 Inner hook 5,35,45 Rail 16,36,50 Rail portion 17,37,51 Covering member 18 Thread division 22,38 Small hole 71 Inner hook 74 Rail member 82 Outer hook

 ──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-6-170075 (JP, A) JP-A-6-238084 (JP, A) JP-A-4-89892 (JP, A) JP-A-2- 206638 (JP, A)

Claims (4)

(57) [Claims] 1. An inner sewing machine in which an inner hook rail fits into a steel outer hook rail groove of 6000-10000 rpm. The covering member is formed integrally from the thread splitting portion to the thread pull-out portion of the rail portion to form a rail, and the covering member is formed when industrial sewing machine oil is interposed between the outer member and the inner peripheral surface of the outer groove. The torque required for the rotary drive of the outer kettle is made of a synthetic resin that is larger than the torque when the industrial sewing machine oil is not interposed, and the synthetic resin is an aromatic polyimide resin. Oil-free full-rotary kettle. 2. The coating member has a thickness t of 0.3 to 0.5 m.
The oil-free full-rotation kettle of the industrial sewing machine according to claim 1, wherein m is an integer. 3. The oil-free full rotation kettle of an industrial sewing machine according to claim 2, wherein grooves 20 are formed on both sides of the rail portion 16, respectively, and the covering member is fitted in the grooves 20. Bitten. 4. A plurality of small holes extending in the thickness direction of the rail portion at intervals in the circumferential direction on the rail portion, and the small hole is filled with a covering member. 1. An oilless full rotation kettle of the industrial sewing machine described in 1.