JP3748603B2 - Sewing machine horizontal rotary hook - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a horizontal rotary hook mounted on a sewing machine, and more particularly to a technique for preventing leakage of lubricating oil supplied to the horizontal rotary hook.
[0002]
[Prior art]
FIG. 3 is a diagram for explaining a lubricating oil circulation path in an automatic oiling machine equipped with a conventional horizontal rotary hook 100 (the flow of oil is indicated by arrows).
As shown in the figure, the lubricating oil of the sewing machine is circulated by a refueling reed pump 50. The oil circulation path will be described. The lubricating oil in the oil reservoir 51 ascends the sewing machine head 53 via the flow path 52 and branches into the flow paths 54 and 55, one being supplied to the surface portion 56 and the other being the sewing machine. The oil tank 57 provided in the upper part of the head 53 is entered. The oil in the oil tank 57 naturally falls through the flow path 58 and flows to the hook shaft base 59, and is supplied to the horizontal rotary hook 100 provided on the hook shaft base 59. The oil supplied to the horizontal rotary hook 100 is refluxed through the flow path 60. Reference numeral 61 denotes an oil reservoir at the bottom of the hook shaft base 59.
[0003]
FIG. 4 is a longitudinal sectional view of a horizontal rotary hook 100 provided in a conventional automatic oiling machine.
The horizontal rotary hook 100 includes an outer hook 2, a recess 3 is provided at the tail end of the outer hook 2, a groove 4 is formed on the inner surface of the recess 3, and an inner hook 5 is provided in the groove 4. It is fitted so that it can slide and rotate. The hook shaft 6 is a cylindrical member inserted into the outer hook 2, and a cylindrical oil supply shaft 7 is inserted into the hollow portion of the hook shaft 6 so as to be slidably rotatable. A spiral groove 8 is formed on the peripheral surface of the oil supply shaft 7. As the hook shaft 6 rotates, the oil travels along the groove 8 and rises from the base end side to the tail end side of the oil supply shaft 7, and supplies lubricating oil to the sliding portion between the outer hook 2 and the inner hook 5. .
[0004]
The base end side of the outer hook 2 is supported by the hook shaft base 59 via a bearing 9 so as to be rotatable. A cylinder portion 10 for preventing oil scattering is fixed to the hook shaft base 59, and the outer hook 2 is inserted into the cylinder portion 10. A space 11 is formed in a portion surrounded by the outer hook 2, the cylindrical portion 10, and the bearing 9, and the oil that is partially supplied to the sliding portion between the outer hook 2 and the inner hook 5. Inflow. The space (gear chamber) 14 in the hook shaft base 59 provided with the gear 13 for driving the horizontal rotary hook 100 causes the oil that has passed through the bearing 9 to flow down from the space 11 and passes through the flow path 60 (see FIG. 3). A reflux path for refluxing the oil.
[0005]
The outer hook 2 and the hook shaft 6 are fixed. The central portion of the bottom of the recess 3 is recessed to form an oil collecting chamber 15, and the oil collecting chamber 15 is sealed with a disk-shaped member 12 . The base end side of the oil supply shaft 7 is fixed to the lower portion of the shuttle shaft base 59, and the tail end portion faces the oil collecting chamber 15. An annular recess 16 is formed on the base end side of the outer hook 2, and a flow path 18 that passes from the oil collecting chamber 15 to the recess 16 passes through the outer hook 2. A ring 17 is fitted in the recess 16. A channel 19 that extends from the recess 16 to the bottom of the recess 3 is formed in a portion of the outer hook 2 that is opposite to the portion where the channel 18 is formed across the oil supply shaft 7. An oil amount adjusting screw 20 is screwed into a side portion of the outer hook 2, and the width of the flow path 19 can be widened or narrowed by the oil amount adjusting screw 20. A portion of the bottom of the recess 3 that extends from the periphery of the flow path 19 to the inner hook 5 is recessed and forms an oil reservoir 21.
[0006]
According to the horizontal rotary hook 100 having the above-described configuration, when the hook shaft 6 rotates, oil is raised from the oil reservoir 61 (see FIG. 3) along the groove 8 to the oil collecting chamber 15. Due to the centrifugal force, the oil in the oil collecting chamber 15 descends the flow path 18 and is pushed out into the recess 16. A small amount of the oil accumulated in the recess 16 rises in the flow path 19 by centrifugal force, and the other oil is pushed out into the space 11 and flows down through the gear chamber 14 from the gap of the bearing 9 to be refluxed. The amount of oil flowing up into the recess 3 through the flow path 19 can be adjusted by the oil amount adjusting screw 20. The oil flowing into the recess 3 is supplied to the groove 4 through the oil chamber 21.
[0007]
[Problems to be solved by the invention]
The conventional horizontal rotary hook 100 as described above has the following problems.
That is, the oil is supplied to the hook shaft base 59 side even when the reed pump 50 is operated at a low speed or when the operation is stopped. The reason is the hydraulic pressure due to the drop h between the oil tank 57 and the shuttle shaft 59 (see FIG. 3). In this case, the oil is supplied to the shuttle shaft 59 side in a sandwich state with air. For this reason, oil and air flow into the space 11 in a sandwich state.
[0008]
However, when an oil film is generated on the bearing 9 due to the surface tension, air cannot escape from the bearing 9 toward the gear chamber 14 , and oil and air stay in the space 11 . On the other hand, since the horizontal rotary hook 100 has heat, the air expands and the internal pressure in the space 11 increases. As a result, the outer hook 2 and the cylinder for preventing the oil scattering are prevented from passing through the gap between the bearings 9 and to the oil and air in the space 11 which are pushed up by the increase of the internal pressure in the space 11 . There is only a small clearance 22 between the part 10 and the escape place. For this reason, oil and air alternately escape from the gap 22 (gep phenomenon), thereby causing a problem of oil leakage from the gap 22.
[0009]
An object of the present invention is to provide a horizontal rotary hook for a sewing machine that solves the above-described problems and does not cause oil leakage even when the operation of the sewing machine is stopped.
Furthermore, another object of the present invention is to provide a horizontal rotary hook for a sewing machine that does not cause oil leakage even when the operation of the sewing machine is stopped and that does not interfere with oil reflux.
[0010]
[Means for Solving the Problems]
Means for solving the above-described problems will be described with corresponding member names and reference numerals in the embodiments of the invention described later.
[0011]
The invention according to claim 1, the outer hook (2), the outer and kettle tail end are slidably disposed side middle hook (5), said outer holder and middle hook sliding portion ( An oil supply portion (oil supply shaft 7, hook shaft 6, etc.) for supplying lubricating oil to the groove 4 and the sliding portion of the inner hook 5, and a bearing portion (bearing 9) mounted on the base end side of the outer hook A hook shaft base (59) for supporting the bearing portion, a cylinder portion (10) fixed to the hook shaft base, an oil tank (57) provided at an upper portion of a sewing machine head, and the oil tank. An oil supply pump (50) for supplying lubricating oil in the oil reservoir (51), a space portion (space 11) formed by the outer hook at the top, the cylinder portion at the side, and the bearing portion at the bottom. the provided, at the sewing machine operation is stopped by the oil tank and the shuttle shaft base of the height difference (h), the lubricating oil in the oil tank is naturally A defeated by horizontal rotary hook of a sewing machine that flows into the space (1), together with the escape of oil in the space portion while bypassing the bearing portion, a portion is formed by the outer peripheral portion of said bearing portion that the bypass flow path (23), said oil return passage for returning the lubricating oil flowing down through the bearing part (gear chamber 14), wherein the bypass flow path surface tension and viscosity resistance of the lubricating oil This is a horizontal rotary hook for a sewing machine that allows the lubricating oil and air to naturally flow down from the space portion to the oil ring passage .
[0012]
In order to make the oil and air naturally flow down from the space part against the surface tension and viscous resistance of the oil, the bypass flow path is resistant to the surface tension and viscous resistance of the oil. Can be realized by selecting the diameter size, shape, etc. of the bypass channel so that it can naturally flow down from the space.
[0013]
According to the horizontal rotary hook of the sewing machine according to claim 1, since the oil and air staying in the space part can flow naturally from the bypass flow path, bypassing the bearing part, the horizontal rotary hook support part and the outer hook Oil does not leak out due to the getp phenomenon.
Therefore, it is possible to provide a horizontal rotary hook for a sewing machine that does not cause oil leakage even when the operation of the sewing machine is stopped.
[0015]
Furthermore, according to the horizontal rotary hook of the sewing machine according to claim 1 , the bypass flow path leads to an oil recirculation path for recirculating oil that has flowed down through the bearing portion during normal operation, The oil in the space can be recirculated without any trouble.
[0016]
DETAILED DESCRIPTION OF THE INVENTION
FIG. 1 is a longitudinal sectional view of a horizontal rotary hook 1 of a sewing machine according to an embodiment of the present invention, and FIG. 2 is a view taken along the line XX of FIG. 1 and 2, and in the following description, members having the same reference numerals as those in FIGS. 3 and 4 are the same as those in the case of the conventional horizontal rotary hook 100 described above, and detailed description thereof is omitted.
[0017]
First, the configuration will be described.
Referring to FIGS. 1 and 2, reference numeral 23 denotes a bypass flow path that characterizes the present invention.
The bypass passage 23 is formed in the shuttle shaft 59 and the cylinder portion 10, and is a groove that connects the space 11 and the gear chamber 14, and bypasses the bearing 9 to release oil in the space 11 to the gear chamber 14. Yes, the oil and air naturally flow down from the space 11 against the surface tension and viscous resistance of the oil. “To make oil and air naturally flow down from the space 11 against the surface tension and viscous resistance of the oil”, the oil and air can naturally flow down from the space against the surface tension and viscous resistance of the oil. Thus, it can be realized by selecting the diameter size and shape of the bypass channel 23. For this reason, the bypass channel 23 shown in FIGS. 1 and 2 is also made not to have a small diameter size so that oil can naturally flow down, and the curved surface shape of the bypass channel 23 is also substantially arcuate.
[0018]
Next, the operation will be described.
According to the horizontal rotary hook 1 of the sewing machine having the above-described configuration, the oil and air staying in the space 11 can flow naturally from the bypass flow path 23 by bypassing the bearing 9. Oil does not leak out between the tube portion 10 and the outer pot 2 due to the getp phenomenon.
Therefore, it is possible to provide a horizontal rotary hook for a sewing machine that does not cause oil leakage even when the operation of the sewing machine is stopped.
[0019]
Further, the bypass flow path 23 communicates with the gear chamber 14 that forms a return path for returning oil via the flow path 60 (see FIG. 3), and the oil in the space 11 can be released to the oil return path. Therefore, there is no hindrance to refluxing the oil in the space 11.
[0020]
Needless to say, the embodiment of the invention described above does not limit the invention.
For example, the shape or the like of the bypass flow path 23 is shown in FIGS. 1 and 2 as long as oil and air in the space 11 can naturally flow down from the space 11 against the surface tension and viscous resistance of the oil. Various selections other than those shown may be made.
[0021]
In the above-described embodiment of the invention, only one bypass channel 23 is formed, but a plurality of bypass channels 23 may be formed.
[0022]
【The invention's effect】
According to the first aspect of the present invention, it is possible to provide a horizontal rotary hook for a sewing machine that does not cause oil leakage even when the operation of the sewing machine is stopped and that does not interfere with oil reflux .
[Brief description of the drawings]
FIG. 1 is a longitudinal sectional view of a horizontal rotary hook of a sewing machine according to an embodiment of the present invention.
FIG. 2 is a view taken along arrow XX in FIG.
FIG. 3 is a diagram for explaining a lubricating oil circulation path in an automatic oiling machine equipped with a conventional horizontal rotary hook.
FIG. 4 is a longitudinal sectional view of a horizontal rotary hook of a conventional sewing machine.
[Explanation of symbols]
DESCRIPTION OF SYMBOLS 1 Horizontal rotary hook 2 Outer hook 4 Groove 5 Middle hook 6 Hook shaft 7 Oil supply shaft 8 Spiral groove 9 Bearing 10 Tube part 11 Space 14 Gear chamber 59 Hook shaft stand

Claims (1)

An outer pot,
An inner hook provided slidably on the tail end side of the outer hook;
An oil supply section for supplying lubricating oil to sliding portions of the outer hook and the inner hook;
A bearing portion mounted on the base end side of the outer hook;
A shuttle shaft base that supports the bearing portion;
A cylindrical portion fixed to the shuttle shaft,
An oil tank provided at the top of the machine head;
An oil supply pump for supplying oil in the oil reservoir to the oil tank;
The upper part is formed by the outer pot, the side part is formed by the cylindrical part, and the bottom part is formed by the bearing part .
When the sewing machine is stopped, a horizontal rotary hook of the sewing machine in which the lubricating oil in the oil tank naturally falls and flows into the space due to a difference in height between the oil tank and the hook shaft base ,
Bypassing the bearing part and escaping oil in the space part, and a bypass flow path partially formed by the outer peripheral part of the bearing part ;
An oil recirculation path for recirculating lubricating oil flowing down through the bearing portion ,
It said bypass flow path is one which naturally flows down to the oil ring channel the lubricating oil and air from said space against the surface tension and the viscosity resistance of the lubricating oil, the horizontal rotary hook of a sewing machine.

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