JPH10272274A - Shuttle for sewing machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To smoothly rotate at a high speed through a long period without oiling by constituting at least one surface of at least one of an orbital groove and an orbital line of high polymer composition obtained by impregnating a lubricant to a polyimide resin so as to make excellent in heat resistant deformability. SOLUTION: A vertically and fully rotating shuttle 1 integrally forms a sliding layer 11 consisting of high polymer composition consisting of a polyimide resin and the lubricant such as silicone oil on the surface of the orbital line of an inner shuttle. As the polyimide resin consisting apart of the material of this layer 11 is provided with 380 deg.C melting point and about 340 deg.C heat distortion temperature (ASTM D648, 18.6 Kgf/cm<2> ), which are extremely high, the polyimide resin is provided with sufficient strength against heat and a load generated on a contact face being the sliding part of the orbital line 9 of the inner shuttle 4 and the orbital groove 10 of an outer shuttle 3 when the shuttle 1 is rotated faster than 800 rpm. Consequently the deformation of the contact face being the sliding part of the orbital line 9 of the inner shuttle 4 and the orbital groove 10 of the outer shuttle 3 are surely prevented.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine hook, and more particularly to a sewing machine hook suitable for an industrial sewing machine that rotates at high speed.

[0002]

2. Description of the Related Art Generally, a conventional shuttle of a sewing machine is formed of a steel material. Therefore, a friction coefficient between a rail of an inner shuttle and a rail groove of an outer shuttle in which the inner rail is fitted is large. is there. And, due to the large friction coefficient between the rail and the groove, a large pressing force is generated on the inner surface of the concave portion of the inner hook where the hook stopper member that prevents the rotation of the inner hook and the inner hook is fitted with the hook member, As a result, it is known that the upper thread cannot be pulled out smoothly, the tension of the upper thread changes, the quality of the sewn product deteriorates, and the rails and the track grooves wear.

As one means for solving such a problem, lubricating oil is supplied between a rail of an inner hook and a rail groove of an outer hook in which the rail of the inner hook is fitted. Although a sewing machine hook has been proposed, the upper thread, the lower thread, the sewing product, and the like may be stained by the lubricating oil, and there has been a problem that the quality of the sewn product cannot always be properly maintained.

[0004] As one means for solving the above-mentioned problems, there has been proposed a shuttle that can be used in an oilless state. JP-A-8-117472 discloses an example of this type of kettle in which a liquid crystal polymer, an aromatic polyimide, or a synthetic resin containing a reinforcing material is used for the rail of the inner kettle or the groove of the outer kettle. Is disclosed. However, in an industrial sewing machine, a kettle usable in a non-lubricated state is used at a high speed rotation of 6000 to 10000 spm.
When used at high speeds of more than pm, the self-lubricating properties of the synthetic resin itself or the synthetic resin itself containing the reinforcing agent reduce the torque generated in the rails of the inner kettle and the rail groove of the outer kettle to reduce Due to the problem that the pressing force generated on the inner surface of the concave portion of the shuttle can not be reduced and the upper thread cannot be pulled out smoothly, and the wear resistance of the synthetic resin itself or the synthetic resin itself containing the reinforcing agent causes the rail and There is a problem that wear of the track groove cannot be prevented.

In order to solve these problems, it is considered to be better to combine the advantages of supplying lubricating oil and the advantages of using synthetic resin into one. As such, a kettle using high-density polyethylene containing a lubricant is disclosed in Japanese Patent Publication No. 7-75638.

[0006]

However, in the above described kettle using high-density polyethylene containing a lubricant, first, the melting point of high-density polyethylene is 1%.
The heat deformation temperature of high-density polyethylene is around 50 ° C (ASTM (American Society of Tes
ting Materials) D648 18.6kgf / cm ² )
Secondly, when the industrial sewing machine is operated at 4000 spm, the kettle is usually 8000.
At this time, the contact surface as a sliding portion between the rail of the inner pot and the rail groove of the outer pot has a characteristic that the temperature rises to 50 ° C. or higher. 8000 spm
The load generated on the contact surface between the rail of the inner pot and the groove of the outer pot when rotating at a speed of at least 18.6 kgf / cm ² defined in ASTM D648 is characteristic. The following problems arise from at least three reasons:

That is, when a kettle using high-density polyethylene containing a lubricant is rotated at 8000 spm or more, an inner pot using high-density polyethylene containing a lubricant is generated by heat and load generated by rotation of the kettle. Since the contact surface of the rail or the sliding portion of the rail groove of the outer hook is easily deformed, and the load applied during one rotation of the hook fluctuates, the rail of the inner hook having a substantially perfect circle is formed. Alternatively, at least one surface of the track groove of the outer hook is deformed into an ellipse, and as a result, it is not possible to smoothly perform the thread removal of the upper thread which is normally performed at the time of sewing operation, and the tension of the upper thread changes. As a result, there is a problem that the quality of the sewn product deteriorates. In addition, the deformation of the rail of the inner pot or the groove of the outer pot causes abnormal heat generation and abrasion, and in some cases, the synthetic resin may be melted, resulting in reduced durability of the pot. there were.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and has as its object to provide a sewing machine hook which is excellent in heat deformation resistance and can be smoothly rotated at high speed for a long time without lubrication. .

[0009]

SUMMARY OF THE INVENTION In order to achieve the above-mentioned object, the present inventors have developed a sewing machine hook which is excellent in heat deformation resistance and can be smoothly rotated at high speed without lubrication for a long period of time. As a result of extensive research over a period of time, at least the surface of at least one of the rails of the inner kettle of the kettle and the rail groove of the outer kettle is formed by a polymer composition containing a lubricant in a polyimide resin, The present inventors have found that a high-speed rotation can be smoothly performed over a long period of time without lubrication, and the present invention has been completed.

That is, a feature of the sewing machine hook of the present invention described in claim 1 is that in the sewing machine hook in which the rail of the inner hook is fitted into the rail groove of the outer hook, And at least one surface of at least one of the rails is formed of a polymer composition comprising a polyimide resin and a lubricant. And, by adopting such a configuration, the excellent heat-resistant deformation property of the polyimide resin is caused by the contact between the rail of the inner pot and the rail groove of the outer pot which occurs when the pot is rotated at high speed. Deformation of the contact surface, which is the sliding portion of the rail of the inner pot or the rail groove of the outer pot, due to the rise in surface temperature can be reliably prevented.

Examples of the polyimide resin constituting a part of the polymer composition used in the sewing machine pot of the present invention include polyimide resin (PI), polyamideimide (PAI) and the like.

As a lubricant constituting a part of the polymer composition used in the sewing machine pot of the present invention, a lubricating oil having a thermogravimetric weight loss at 300 ° C. of 10% by weight or less in thermogravimetric weight loss measurement is preferably used. Specifically, silicone oil, perfluoroether oil,
Examples thereof include phenyl ether oil.
Specific examples of the amount of the lubricant include 0.1 to 11 parts by weight, preferably 0.2 to 10 parts by weight, particularly preferably 0.1 to 10 parts by weight, based on 100 parts by weight of the polyimide resin. The range of 5 to 8 parts by weight is optimal. If the amount of the lubricant is less than this range, the sliding resistance of the contact surface, which is the sliding part between the rail of the inner pot and the groove of the outer pot, when the pot is rotated at high speed is reduced over a long period of time. When the amount exceeds this range, the properties of the thermoplastic resin are impaired, and the moldability of the polymer composition by injection molding or the like tends to decrease.

The polymer composition used in the sewing machine pot of the present invention preferably contains a fiber reinforcing material so that the properties of the polymer composition can sufficiently withstand use as the sewing machine pot. As this fiber reinforcement, carbon fiber, glass fiber,
Potassium titanate fiber, ceramic fiber, metal fiber, boron fiber, silicon carbide fiber, asbestos fiber, rock wool fiber and aramid fiber can be exemplified,
These may be used alone or in combination. As a specific compounding example of the fiber reinforcing agent, a range of 1 to 80 parts by weight, preferably a range of 1 to 70 parts by weight, particularly preferably 1 to 6 parts by weight with respect to 100 parts by weight of the polyimide resin.
A range of 0 parts by weight is optimal. If the compounding amount of the fiber reinforcing material is less than this range, properties such as mechanical strength, dimensional accuracy, dimensional stability, abrasion resistance and surface roughness that can sufficiently withstand use as a sewing machine of a sewing machine are sufficiently obtained. There is a tendency that it cannot be improved, and if it exceeds this range, the melt viscosity of the polymer composition increases, the moldability of the polymer composition by injection molding and the like decreases, and the fiber component occupies compared to the resin component When the ratio is extremely large, the fibers are easily broken, and the broken fibers tend to adhere to the sliding portion and adversely affect the sliding characteristics.

The polymer composition used for the sewing machine pot of the present invention includes fluorine resin, graphite, calcium carbonate, mica, glass beads, molybdenum disulfide, clay, silica, alumina, talc, diatomaceous earth, Various compounding agents such as fillers such as alumina and shirasu balloon, lubricants, release agents, stabilizers, coloring agents, crystal nucleating agents, softeners and plasticizers may be contained alone or in combination as necessary. it can.

Further, the polymer composition used in the sewing machine pot of the present invention includes polyethersulfone, polyimide, polyetherimide, polysulfone, polycarbonate, and the like.
Other non-crystalline resins such as polyarylate, polyphenylene sulfide, polyether nitrile, polyamide,
Other crystalline resins such as polyetherketone, polyetheretherketone, polyetherketoneetheretherketoneketone, polyetherketoneketone, polyetheretherketoneketone, liquid crystal polymer, epoxy resin, polyimide resin, silicone resin, polyamide Other thermosetting resins such as imide resin and polybenzimidazole resin can be used alone or in combination as needed.

A molded article using the polymer composition used for the sewing machine pot of the present invention is heat-treated at a temperature of 250 to 350 ° C. to crystallize the polyimide resin in the polymer composition, The performance of the crystalline polymer is exhibited.

The polymer composition used in the sewing machine pot of the present invention may have a structure in which a lubricant is contained not only in a polyimide resin but also in a polyether ether ketone or polyphenylene sulfide. .

[0018]

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

FIGS. 1 to 4 show a first embodiment of a sewing machine hook according to the present invention. FIG. 1 is a longitudinal sectional view showing a main part of the entire structure, and FIG. 1 is a front view of the inner kettle of FIG. 1, FIG. 3 is a front view of the outer kettle of FIG. 1, and FIG. 4 is an enlarged view of a part where the rail of the inner kettle of FIG. It is a partially expanded longitudinal sectional view.

As shown in FIG. 1, a vertical full rotary hook 1 as a hook of a sewing machine according to the present embodiment is fixed to one end of a lower shaft 2, and when a sewing machine (not shown) is operated, an arrow shown in FIG. An outer shuttle 3 is rotated at a high speed in a direction shown by the arrow, and an inner shuttle 4 is housed in the outer shuttle 3. The inner hook 4 is fixed to a sewing machine body (not shown) when the outer hook 3 rotates, and fits into a recess 5 formed in the inner hook 4 by a hook stopper 6 partially shown by an imaginary line in FIG. Rotation is prevented. A detachable bobbin case 7 is attached to the inner pot 4.
The bobbin case 7 houses a detachable bobbin 8 around which a bobbin thread (not shown) is wound. Further, a rail 9 is formed on the outer peripheral surface of the peripheral wall of the inner pot 4 as shown in FIG. 2, and a rail groove 10 is formed on the inner peripheral surface of the peripheral wall of the outer pot 3 as shown in FIG. Is formed, and the rail 9 of the inner hook 4 enters and fits into the rail groove 10.

A sliding layer 11 is formed on the surface of the rail 9 of the inner hook 4 as shown in detail in FIG. The sliding layer 11 is formed of a polymer composition obtained by adding a lubricant to a polyimide resin. For example, the polymer composition is weighed at a ratio of 1.5 parts by weight of a silicone oil as a lubricant to 100 parts by weight of a polyimide resin (total 101.5 parts by weight). Are dry-blended using a mixer, and then extruded at 370 to 400 ° C. using an extruder, and then pelletized using a polymer composition obtained by granulation. It is integrally formed by performing injection molding on a mounted mold using an injection molding machine.

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

The vertical full-rotation hook 1 of the present embodiment comprises an inner hook 4
A sliding layer 11 formed of a polymer composition comprising a polyimide resin and silicone oil is integrally formed on the surface of the rail 9 of the above, and the polyimide resin constituting a part of the material of the sliding layer 11 is formed. Has a melting point of 380 ° C. and a heat deformation temperature of about 340 ° C. (ASTM D648818.6 kgf /
cm ² ), which is 8000 sp
m, it has sufficient strength against heat and load generated on the contact surface, which is a sliding part between the rail 9 of the inner hook 4 and the rail groove 10 of the outer hook 3 when rotating at more than m. Deformation of the contact surface serving as a sliding portion between the rail 9 of the shuttle 4 and the rail groove 10 of the outer shuttle 3 can be reliably prevented, and as a result, the upper thread (not shown) can be smoothly removed. Stable and high-quality sewing product quality can be reliably maintained for a long period of time.

The silicone oil as a lubricant contained in the polyimide resin constituting a part of the material of the sliding layer 11 has a thermal weight loss at 300 ° C. of 10% by weight.
Since it has the following heat resistance, the rail 9 of the inner hook 4 and the rail of the outer hook 3 are also heated by the heat generated on the contact surface which is a sliding portion between the rail 9 of the inner hook 4 and the groove 10 of the outer hook 3. The self-lubricating performance of the contact surface serving as the sliding portion with the groove 10 in the non-lubricated state can be reliably maintained for a long period of time, and the inner hook 4 when the vertical full rotary hook 1 rotates at 8000 spm or more.
And the torque as a sliding resistance generated in the outer hook 3 can be reduced, and the force applied to the inner surface of the recess 5 formed in the inner hook 4 into which the hook 6 is fitted can be reduced. The upper thread can be pulled out more smoothly, and a stable, high-quality sewing product in a non-lubricated state can be reliably maintained for a long period of time.

That is, the vertical full rotary hook 1 of the present embodiment.
Due to the excellent heat-resistant deformation of the sliding layer 11 formed on the surface of the rail 9 of the inner pot 4, it can be smoothly rotated at high speed without lubrication for a long period of time.

Since the polymer composition of the present invention containing a lubricant in the polyimide resin can be injection-molded, this polymer material is injection-molded to form the complex The entire outer kettle 3 and inner kettle 4 can be formed, and by using the vertical full rotary hook 1 having such a configuration, similar to the above-described embodiments, the lubrication can be performed without lubrication for a long period of time. It is possible to smoothly rotate at a high speed, reduce the weight of the outer hook 3 and the inner hook 4 and reduce the inertia force when the outer hook 3 rotates due to the weight reduction, and make the upper thread slip off more smoothly. be able to.

Further, according to the present invention, the rail groove 9 of the inner hook 4 is provided.
And at least one surface of at least one of the rails 10 of the outer kettle 3 is formed of a polymer composition obtained by adding a lubricant to the polyimide resin of the present invention, and at least another portion of the outer kettle 3 is formed of another resin material ( (A thermosetting polyimide etc.) to reduce the weight of the outer hook 3 and to reduce the inertia force when the outer hook 3 rotates due to the weight reduction, and to make the upper thread slip off more smoothly. Can be.

Furthermore, by adding a fiber reinforcing agent such as a PAN-based carbon fiber to the polymer composition comprising the polyimide resin of the present invention and a lubricant, the mechanical strength when injection molding is performed. In addition, characteristics such as dimensional accuracy, dimensional stability, and surface roughness can be further improved.

FIG. 5 shows a second embodiment of a vertical full rotary hook to which the sewing machine hook according to the present invention is applied. The vertical full rotary hook 1A of this embodiment is a rail of the inner rotary hook 4A. 9A
Is entirely formed of a polymer composition comprising the same polyimide resin as the polyimide resin as the sliding layer 11 of the first embodiment and a silicone resin as a lubricant. Other configurations are the same as those of the first
This is the same as the embodiment.

With this configuration, the present embodiment employs a polymer composition comprising a polyimide resin as a polyimide resin and a silicone resin as a lubricant as in the first embodiment. Inner pot 4 formed
Due to the excellent heat deformation resistance of the rail 9A of A, it can be smoothly rotated at high speed for a long time without lubrication.

FIG. 6 shows a third embodiment of a vertical full rotary hook 1B to which the sewing hook of the sewing machine according to the present invention is applied. Groove 10
The surface of B is formed by a sliding layer 11 made of a polymer composition obtained by adding a silicone resin as a lubricant to a polyimide resin as the same polyimide resin as the sliding layer 11 of the first embodiment described above. It is formed. Other configurations are the same as those of the above-described first embodiment.

With this configuration, the present embodiment employs a polymer composition comprising a polyimide resin as a polyimide resin and a silicone resin as a lubricant, as in the first embodiment described above. Outer pot 3 formed
Due to the excellent heat-resistant deformation of the sliding layer 11 on the surface of the rail groove 10B of B, it is possible to smoothly rotate at high speed without lubrication for a long period of time.

FIG. 7 shows a fourth embodiment of a vertical full rotary hook to which the sewing machine hook according to the present invention is applied. The vertical full rotary hook 1C of this embodiment is the same as that shown in FIG. The inner pot 4 of the first embodiment described above and the third pot shown in FIG.
And the outer hook 3B of the embodiment.
That is, in the present embodiment, both the surface of the rail 9 of the inner pot 4 and the surface of the rail groove 10B of the outer pot 3B contain a polyimide resin as a polyimide resin and a silicone resin as a lubricant. A sliding layer 11 made of a polymer composition is provided. Other configurations are the same as those of the above-described first embodiment.

With this configuration, the present embodiment is similar to the first to third embodiments described above, and includes a high-level structure obtained by adding a silicone resin as a lubricant to a polyimide resin as a polyimide resin. Due to the excellent thermal deformation resistance of the sliding layer 11 on each surface of the rail 9 of the inner pot 4 and the track groove 10B of the outer pot 3B formed of the molecular composition, the lubrication is smoothly performed at high speed for a long time without lubrication. be able to.

FIG. 8 shows a fifth embodiment of a vertical full-rotation hook to which the sewing machine hook according to the present invention is applied. The vertical full-rotation hook 1D of this embodiment is the same as that shown in FIG. This is a combination of the inner shuttle 4A of the second embodiment described above and the outer shuttle 3B of the third embodiment shown in FIG. 6 described above. That is, in the present embodiment, the entirety of the rail 9A of the inner hook 4A and the sliding layer 11 on the surface of the rail groove 10B of the outer hook 3B are combined with a polyimide resin as a polyimide resin and a silicone resin as a lubricant. Is formed from a polymer composition containing Other configurations are the same as those of the above-described first embodiment.

With this configuration, this embodiment is similar to the first to third embodiments described above, except that a polyimide resin as a polyimide resin contains a silicone resin as a lubricant. The entire rail 9A of the inner kettle 4A formed by the molecular composition and the rail groove 10B of the outer kettle 3B
Due to the excellent heat deformation resistance with the sliding layer 11 on the surface of the substrate, it can be smoothly rotated at high speed without lubrication for a long time.

The present invention is not limited to the above embodiments, but can be modified as needed.

[0038]

As described above, according to the sewing machine hook of the present invention, at least one surface of the contact surface, which is the sliding portion between the rail of the inner hook and the rail groove of the outer hook, is made of a polyimide resin with a lubricant. Is formed by a polymer composition containing
Since this polymer composition has excellent heat deformation resistance, the contact surface serving as a sliding portion between the rail of the kettle and the rail groove of the outer kettle can be rotated at a high speed for a long period of time without lubrication, As a result, there is an extremely excellent effect that stable and high quality sewing product quality can be reliably maintained for a long period of time.

[Brief description of the drawings]

FIG. 1 is a longitudinal sectional view showing a main part of an entire configuration of a first embodiment in which a sewing machine hook according to the present invention is applied to a vertical full-rotation hook.

FIG. 2 is a front view of the inner pot of FIG. 1;

3 is a view similar to FIG. 2 of the outer hook of FIG. 1;

FIG. 4 is a partially enlarged longitudinal sectional view showing, in an enlarged manner, a portion where the rail of the inner kettle of FIG.

FIG. 5 is a view similar to FIG. 4 showing, in an enlarged manner, a portion where a rail of an inner hook is fitted in a rail groove of an outer hook in a second embodiment in which the sewing machine hook according to the present invention is applied to a vertical full rotation hook. Illustration

FIG. 6 is an enlarged view of a part where the rail of the inner hook is fitted into the rail groove of the outer hook according to the third embodiment in which the sewing machine hook according to the present invention is applied to a vertical full-rotation hook. Illustration

FIG. 7 is a view similar to FIG. 4 showing, in an enlarged manner, a portion where a rail of an inner hook is fitted in a rail groove of an outer hook in a fourth embodiment in which the sewing hook of the sewing machine according to the present invention is applied to a vertical full rotation hook. Illustration

FIG. 8 is a view similar to FIG. 4 showing, in an enlarged manner, a portion in which a rail of an inner hook is fitted into a rail groove of an outer hook in a fifth embodiment in which the sewing machine hook according to the present invention is applied to a vertical full rotation hook. Illustration

[Explanation of symbols]

1, 1A, 1B, 1C, 1D (as a sewing machine pot)
Vertical full rotary hook 3, 3B Outer hook 4, 4A Inner hook 9, 9A Rail 10, 10B Rail groove 11 Sliding layer

Claims (1)

[Claims] 1. A sewing machine hook in which a rail of an inner hook is fitted into a rail groove of an outer hook, wherein at least one surface of at least one of the rail groove and the rail is made of a polyimide resin containing a lubricant. A sewing machine pot formed by a molecular composition.