JPH0532074Y2 - - Google Patents

Description

[Detailed explanation of the idea]

INDUSTRIAL APPLICATION FIELD The present invention relates to a full rotary rotary hook provided in, for example, a lockstitch sewing machine. 2. Description of the Related Art Generally, when a sewing machine is operated at high speed, the outer hook is rotated at high speed around its rotational axis. As a result, frictional heat is generated due to frictional contact between the inner hook rail and the outer hook rail, and when the temperature reaches a high temperature, seizing occurs and noise is generated. Lubricating oil is supplied between the groove and the groove. In such prior art, by supplying lubricating oil, the lubricating oil may adhere to and stain the upper thread sliding on the outer circumferential surface of the inner hook, or the upper thread may become dirty due to the rotation of the outer hook. There was a problem in that the scattered lubricating oil adhered to the bobbin thread wound around the bobbin, staining it. Furthermore, in the prior art, since the inner hook tries to rotate in the same direction as the outer hook rotates, a hook stop recess is formed in the inner hook, and a rotation preventing member fixed to the body of the sewing machine is used to prevent rotation of the inner hook. The inner hook is configured to fit into the hook locking recess and stop the rotation of the inner hook. The needle thread passes between such a hook-lock recess and the hook-stop member. If the outer hook and inner hook are seized as described above, it becomes difficult for the upper thread to smoothly pass between the hook stopper recess and the rotation stopper member and come off. As a result, an undesired large tension is generated in the upper thread, causing problems such as thread breakage and failure to form good seams. Problems to be solved by the invention The purpose of the invention is to eliminate the need for lubricating oil supply, prevent seizure of the inner hook and rotary hook, rotate the outer hook smoothly without making noise, and prevent thread breakage. To provide a full-rotation hook for a sewing machine that can improve the quality of sewing without causing problems. Means for Solving the Problems The present invention is characterized in that a film in which fine particles of molybdenum disulfide are dispersed in a heat-resistant resin is formed on at least one of the outer peripheral surface of the inner rotor and the inner peripheral surface of the outer rotor. There is a full rotation hook on the sewing machine. Effect According to the present invention, a film made of a heat-resistant resin in which fine particles of molybdenum disulfide are dispersed is formed on at least one of the outer circumferential surface of the inner pot or the inner circumferential surface of the outer pot.

【table】

[Table] Such molybdenum disulfide has a small coefficient of friction, for example, the coefficient of friction of molybdenum disulfide itself is 0.04 or less. FIG. 3 is a front view of the outer hook 3 according to another embodiment of the present invention, and FIG. 4 is an enlarged sectional view taken along the section line - in FIG. 3. In the embodiment described above, the film 6 was formed on the outer peripheral surface of the inner rotor 1, but in this embodiment, the film 11 was formed on the inner peripheral surface of the outer rotor 3.
is formed. This film 11 is similar to the film 6 described above.
The coating 11 can be formed on the inner circumferential surface of the outer hook 3 by following the same procedure as when the coating 6 was formed on the inner hook 1. By forming the film 11 on the inner circumferential surface of the outer hook 3 in this way, the inner hook 1 fitted into the raceway groove 4 can be
The inner hook 1 is supported by the outer hook 3 with the rail 2 in contact with the coating 11, and in this state, the outer hook 3 is driven to rotate around the rotational axis. With this, even if the outer hook 3 is rotated at high speed, it can be rotated smoothly without causing noise such as seizure or hook noise. Next, FIG. 5 shows the results of temperature measurements made by the present inventor during rotation of the outer hook. Number of revolutions of the outer hook
An intermittent operation was performed in which the device was rotated at 10,000 rpm for 15 seconds and stopped for 5 seconds, and the temperature was measured at the position indicated by reference numeral 15 in FIG. As described in FIGS. 1 and 2, the line l1 indicates the temperature change when the film 6 is formed on the outer peripheral surface of the inner pot 1, and the line l1
2 shows the temperature change when the film 11 is formed on the inner circumferential surface of the outer hook 10, as described in FIGS. 3 and 4. As shown by these lines l1 and l2, after rotating the outer hook, the temperature will rise from room temperature to 10
The outer hook rotates smoothly even though the temperature remains at about ℃. On the other hand, line l3 shows the temperature change when a Teflon film is formed on the inner pot.
4 shows the temperature change when a Teflon film was formed on the outer hook. At line l4, time t1
= After 95 minutes, the outer hook has seized up and is locked. As shown by these lines l3 and l4, if a Teflon film is formed on the outer circumferential surface of the inner hook or the inner circumferential surface of the outer hook, the temperature of the outer hook will rise over time and eventually seize up. Put it away. According to the results of measuring the temperature of the outer pot by the inventor of the present invention, a film made of a heat-resistant resin in which fine particles of molybdenum disulfide MoS ₂ are dispersed is formed on at least one of the outer circumferential surface of the inner pot or the inner circumferential surface of the outer pot. It is demonstrated that by forming this structure, it is possible to effectively reduce the temperature rise due to sliding friction between the rail and the rail groove, and that high-speed rotation of the outer hook is possible. Effects of the invention According to the invention, a film made of fine particles of molybdenum disulfide dispersed in a heat-resistant resin is formed on at least one of the outer circumferential surface of the inner hook or the inner circumferential surface of the outer hook, so that the sewing machine can be operated easily. At times, the friction between the inner hook rail and the outer hook rail can be reduced as much as possible, eliminating the need for lubricating oil and allowing the outer hook to rotate smoothly without seizure or noise. becomes possible. Further, since the needle thread can slide smoothly on the outer peripheral surface of the inner hook to form a needle thread loop, the sewing operation can be performed at a thread tension suitable for forming high-quality seams. Furthermore, by forming the film on the entire surface of the inner hook and outer hook, steps such as surface finishing can be omitted, manufacturing can be simplified, and there is also a rust-preventing effect.

[Brief explanation of drawings]

Fig. 1 is a front view of an outer hook 1 according to an embodiment of the present invention, Fig. 2 is an enlarged sectional view taken along the cutting plane line - of Fig. 1, and Fig. 3 is an outer hook 1 of an embodiment of the present invention. A front view of the rotary hook 10, FIG. 4 is taken along the cutting plane line of FIG. 3.
FIG. 5 is a graph showing the temperature measurement results of the outer pot by the inventor of the present invention. 1...Inner hook, 2...Rail, 3...Outer hook, 4
...Rail groove, 6,11...Coating.

Claims (1)

[Scope of utility model registration request] A full-rotation hook for a sewing machine, characterized in that a film of fine particles of molybdenum disulfide dispersed in a heat-resistant resin is formed on at least one of the outer circumferential surface of the inner hook or the inner circumferential surface of the outer hook.