JPH0710709Y2 - High speed horizontal full rotary hook for industrial sewing machine - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a high-speed horizontal full rotary hook of an industrial sewing machine with an outer rotary hook having a rotation speed of about 5000 rpm or more, and more particularly to a background art relating to a structure for guiding lubricating oil to a rail groove of the outer rotary hook. Since the outer hook rotates at a rotation speed of about 5000 rpm or more as described above until the high-speed horizontal full rotation of such an industrial sewing machine, lubricating oil is forced between the outer hook groove groove and the inner hook rail. It is necessary to refuel and lubricate, thereby preventing wear between the rail groove and the rail and suppressing heat generation. In a domestic sewing machine in which the outer hook has a low rotational speed, such forced lubrication of lubricating oil is unnecessary.

One proposed technique for such a high speed horizontal full rotary hook of an industrial sewing machine is shown in FIG. The rotary shaft 2 of the outer hook 1 is formed with a storage hole 3 having an inner peripheral surface whose inner diameter is uniform in the vertical axis direction. The oil core 4 is housed in the housing hole 3. The oil core 4 is held on the rotating shaft 2 by a holding member 5. The lower end portion of the rotary shaft 2 of the outer hook 1 has a storage tank 6
It is immersed in the lubricating oil stored in. The lower end of the rotary shaft 2 and the lower bearing 7 constitute a gear pump 8. When the rotary shaft 2 is driven to rotate, the lubricating oil in the storage tank 6 is guided to the guide groove 11 via the passages 9 and 10 by the action of the gear pump 8 and is supplied to the lower end portion of the oil core 4.

After that, the lubricating oil by the gear pump 8 is pushed up along the oil core 4 and is supplied to the rail groove 13 from the supply hole 12 formed in the outer hook 1.

The guide groove 11 communicates with a passage 14 formed in the storage tank 6 and extending in the lateral direction. A passage 15 whose one end opens into the storage space 6a of the storage tank 6 communicates in the middle of the passage 14. An inner thread is engraved at the left end of the passage 14 in FIG. 5, and an adjusting screw 16 is screwed into the inner thread. The adjusting screw 16 is formed in a tapered shape toward the guide groove 11. Therefore, the opening area of the passage 15 is adjusted by screwing the adjusting screw 16 in and out.
With such a configuration, part of the lubricating oil supplied from the guide groove 11 to the lower end of the oil core 4 can be discharged into the storage tank 6 via the passages 14 and 15, and at this time, the adjusting screw 16
The discharge amount can be adjusted by adjusting the opening area of the passage 15. In this way, the amount of lubricating oil supplied to the oil core 4 is adjusted.

Problems to be Solved by the Invention In the above-described prior art, the gear pump 8 is required, the configuration is complicated, and the size is increased.

In this prior art, when the rotation of the outer hook 1 is stopped and the gear pump 8 is stopped, the supply hole 12,
When the lubricating oil is discharged from the holding member 5 and the passages 10, 11, 14 and 15, and then the operation is restarted, the lubricating oil from the gear pump 8 flows through the passages 9, 10 and 11 as described above. Then, it is pushed up via the oil core 4, and further supplied from the holding member 5 to the rail groove 13 via the supply hole 12. Therefore, immediately after the restart of the operation, there is a period in which the lubricating oil is not supplied to the track groove 13. Even if the outer hook 1 is rotating at a high speed after the start of operation, if the state in which the lubricating oil is not supplied continues as described above, the rail groove 13 of the outer hook 1 and the inner hook fitted to the rail groove 13 This will result in rail wear and heat generation.

The object of the present invention is to solve the above technical problems and to provide a high-speed horizontal horizontal sewing machine for industrial sewing machines which has a simple structure and is capable of supplying lubricating oil to the rail groove of the rotary hook immediately after restarting the operation. It is to provide a rotary hook.

MEANS FOR SOLVING THE PROBLEMS The present invention is directed to an outer hook 21 having a groove 21a in which an inner hook rail is fitted on an inner peripheral surface, and an outer hook 21 coaxially fixed to the outer hook 21 so as to rotate around a rotation axis l. The rotary shaft 22 includes a rotary shaft 22 that is driven to rotate, and a storage tank 23 that is disposed near the lower end portion 22b of the rotary shaft 22 and that stores lubricating oil.
With respect to the storage hole 28 having an inner peripheral surface 28a that extends radially outward with respect to, and having an opening 28b that opens at the lower end 22b protruding into the internal space of the storage tank 23, the storage hole 28 Has a hanging portion 30a extending from the lower end portion 22b of the rotating shaft 22 into the storage tank 23, and accommodates an oil core 30 extending over substantially the entire length of the accommodation hole 28, and the outer hook 21 has a groove groove 21a. And a high-speed horizontal full rotation of the industrial sewing machine, which is characterized in that a lubricating oil supply path 33 is formed so as to connect the upper end of the storage hole 28 with the lubricating oil.

Operation According to the present invention, the rotary shaft 22 of the outer hook of the industrial sewing machine is
When rotationally driven at a high speed of 5000 rpm or more, an upward component force due to a centrifugal force acts on the lubricating oil along the inner peripheral surface 28a of the storage hole 28, whereby the lubricating oil rises and Lubricating oil can be supplied to the groove 21a.

The oil core 30 is kept impregnated with the lubricating oil, and the oil core 30 extends over almost the entire length of the storage hole 28. Therefore, even if the rotary shaft 22 is stopped, the rotary drive of the rotary shaft 22 is prevented. Immediately after restarting, the lubricating oil can be supplied to the track groove 21a from the upper part of the oil core 30 via the supply path 33. Ie the axis of rotation 2
When the rotation drive of 2 is restarted, the lubricating oil impregnated in the oil core 30 moves radially outward by the centrifugal force, collides with the inner peripheral surface 28a of the storage hole 28, and the centrifugal force of this lubricating oil Inner surface 28a by
The upward component force along the direction acts, and the lubricating oil rises along the inner peripheral surface 28a. This ensures that the lubricating oil is supplied even at the initial stage of rotation of the rotary shaft 22 and the outer hook 21.

Since the oil core 30 has the hanging portion 30a extending from the lower end portion 22b of the rotating shaft 22 into the storage tank 23, the lubricating oil in the storage tank 23 is consumed and the oil surface is spaced downward from the lower end portion 22b. Even if it is lowered by opening, as long as the hanging portion 30a is immersed in the lubricating oil, the capillary oil of the oil core 30 causes the lubricating oil in the storage tank 23 to be stored in the storage hole 28 of the rotary shaft 22. Therefore, when the rotating shaft 22 rotates, the lubricating oil can be smoothly and sufficiently supplied by the centrifugal force as described above.

Embodiment FIG. 1 is a partial sectional view of a horizontal full rotary hook of an industrial sewing machine according to an embodiment of the present invention. In this industrial sewing machine, the outer hook 21 is rotationally driven at a high speed of about 5000 rpm or more, and therefore, the lubricating oil is supplied to the track groove 21a of the outer hook 21 by the configuration described below to perform lubrication, thereby Wear between the rail groove 21a and the rail of the inner hook fitted to the rail groove 21a is prevented, and heat generation is reduced. Inner hook rail (not shown)
Is fitted into a rail groove 21a formed in the outer hook 21, and the inner hook is stored in the outer hook 21. Lower end of rotating shaft 22 of outer hook 21
In FIG. 1, 22b is immersed in the lubricating oil stored in the storage tongue 23. An inner hook guide ring 24, an upper bearing 25, a gear 26, and a lower bearing 27 are fixed to the outer periphery of the rotary shaft 22 in this order from the upper side to the lower side. Gear 26
Meshes with a gear fixed to the output shaft (not shown) of the motor. As a result, when the motor is energized, the rotary shaft 22 is driven to rotate about the vertical rotary axis l.

The rotary shaft 22 is formed with an end hole 28 having an inner peripheral surface 28a inclined in a direction away from the axial direction as it goes upward. That is, the inner peripheral surface 28a expands outward in the radial direction with respect to the rotation axis l as it goes above the rotation axis 22. The lower end 22b of the rotary shaft 22 projects into the internal space of the storage tank 23, and the storage hole 28 is opened at this lower end 22b, and this opening is indicated by reference numeral 28b. The upper opening of the storage hole 28 is sealed by a lid 29. An oil core 30 made of thread, felt, or the like and extending vertically in FIG. 1 is housed in the housing hole 28. The oil core 30 is formed such that the cross section perpendicular to the axis gradually increases as it goes upward so as to be fitted tightly into the inner peripheral surface 28a of the housing hole 28. The upper end portion of the oil wick 20 extends to the vicinity of the lid body 29, that is, in contact with the lid body 29 or with a gap below. The lower end of the oil wick 30 is immersed in the lubricating oil in the storage tank 23. In this way, the oil core 30 has a hanging portion 30a extending from the lower end portion 22b of the rotating shaft 22 into the storage tank 23,
Moreover, it extends over substantially the entire length of the storage hole 28.

With such a configuration, when the outer rotary shaft 22 of the rotary hook is rotationally driven, the lubricating oil in the storage tank 23 is moved along the inner peripheral surface 28a of the storage hole 22 by utilizing the centrifugal force of the lubricating oil. Is supplied to the supply hole 33.

The oil level of the lubricating oil in the storage tank 23 is the lower end 22b of the rotary shaft 22.
When the lubricating oil is present at a distance lower than the above, the lubricating oil is sucked up by the hanging portion 30a of the oil core 30 by a capillarity phenomenon. Lubricating oil sucked up is attached. Therefore, when the rotary shaft 22 is rotationally driven, the lubricating oil attached to the inner peripheral surface 28a rises by the centrifugal force along the inner peripheral surface 28a.

The outer hook 21 includes a bottom portion 31 and a peripheral wall 32, and applies lubricating oil to the rail groove 21.
A supply hole 33 leading to a is formed. This supply hole 33 is
It includes a first supply hole 33a formed in the bottom portion 31 and a second supply hole 33b formed in the peripheral wall 32. One end portion (the right end portion in FIG. 1) of the first supply hole 33a opens at the upper end portion of the storage hole 28 and faces the oil core 30, and the other end portion (in FIG. 1) of the first supply hole 33a. The left end portion) opens to the outer peripheral surface of the peripheral wall 32 and faces the outside.
The upper end of the second supply hole 33b communicates with the rail groove 21a, and the lower end of the second supply hole 33b communicates with the first supply hole 33a.

An inner screw is engraved on the left side of the first supply hole 33a in FIG. 1 relative to the second supply hole 33b. This adjustment screw 35
Screw together. The second supply hole 33b is filled with an oil core 36 which is made of thread or felt and extends vertically. The cross-sectional area of the oil core 36 is changed by moving the adjusting screw 35 forward and backward. As a result, the lubricating oil is supplied to the first supply hole 33a.
When passing through the oil core 36 and being guided to the track groove 21a,
The flow passage cross section of the lubricating oil is narrowed. By adjusting this throttle amount, it is possible to adjust the amount of lubricating oil supplied from the track groove 21a. Since the supply hole 33 is directly adjusted by the adjusting screw 35, compared with the indirect adjusting mechanism of the proposed technique shown in FIG. It is possible to make fine adjustments to the oil amount.

In addition, in the storage hole 28 of the rotary shaft 22, the guide ring 24, the upper bearing
25, and passages 40, 41 for supplying lubricating oil to the lower bearing 27,
42 is formed.

The principle that the lubricating oil stored in the storage tank 23 is supplied to the supply holes 33 when the rotary shaft 22 is rotationally driven will be described.

Referring to FIG. 2, the storage hole 28 has an inner peripheral surface 28a inclined so as to separate from the axis l as it goes upward.
Observing the particles b of the lubricating oil, when the rotating shaft 22 is driven to rotate, the particles b of the lubricating oil impregnated in the oil core 30 in the storage hole 28 move outward in the radial direction by the centrifugal force, and It collides with the inner peripheral surface 28a of 28. A centrifugal force F0 acts on the particle b on the inner peripheral surface 28a.

Here, m is the mass of the particle b, r is the radius of the inner peripheral surface 28a, ω is the angular velocity of the rotating shaft 22, W is the weight of the particle b, and g is the gravitational acceleration.

Since the inner peripheral surface 28a is inclined with respect to the vertical rotation axis l, the upward molecule F1 due to the centrifugal force F0 acts on the particle b along the inner peripheral surface 28a, and the downward force of gravity is exerted on the particle b. Force F2
Works.

F1 = F0 · sin θ (2) F2 = W · cos θ (3) The angle θ is an angle formed with the rotation axis l of the inner peripheral surface 28a.

When the rotation speed of the rotating shaft 22, and thus the angular velocity ω, increases, the forces F1, F2 acting on the particle b become F1> F2 (4), and the particle b rises along the inner peripheral surface 28a. The ascending particles b reach the upper end of the storage hole 28,
From there, it is guided to the first supply hole 33a. The lubricating oil in the first supply hole 33a is moved outward in the radial direction by the centrifugal force generated by the rotation of the outer hook 21, passes through the adjusting screw 35, and then passes through the second supply hole 33a.
It is pushed up inside b and discharged from the rail groove 21a.

According to an experiment conducted by the inventor of the present invention, when the inner peripheral surface 28a of the rotary shaft 22 is configured so that sin θ = 0.018 and the rotation speed of the outer rotary hook 21 and thus the rotary shaft 22 is about 4000 rpm or more, the storage tank 23 It was confirmed that the lubricating oil inside went up through the storage hole 28 in the rotary shaft 22 and was supplied to the rail groove 21a of the outer hook 21.

Effects According to the present invention, the following effects are achieved.

(1) A storage hole 28 is formed in the rotary shaft 22 and its inner peripheral surface
Since 28a is formed so as to spread radially outward with respect to the rotation axis l as it goes upward, the lubricating oil in the storage hole 28 moves radially outward due to its centrifugal force,
In order that the upward component force F1 along the inner peripheral surface 28a acts on the lubricating oil and exceeds the downward component force F2 along the inner peripheral surface 28a of the gravity W of the lubricating oil, the outer hook of the industrial sewing machine When the rotation speed of 21 is about 5000 rpm or more, the lubricating oil rises along the inner peripheral surface 28a and can be supplied to the track groove 21a of the outer hook 21 from the storage hole 28 through the supply path 33.

This supply amount of the lubricating oil becomes large when the rotation speed of the rotary shaft 22 increases, and the lubrication is sufficiently performed, which is convenient. When the rotary shaft 22 has a low speed like a household sewing machine, the lubricating oil is not supplied to the track groove 21a, but in such a low speed household sewing machine, even if it is not lubricated, the heat generation is small, No hindrance will occur.

(2) The oil core 30 is stored in the storage hole 28,
The hanging portion 30a of the storage tank 23
Since it extends inside, the lower end 22b of the rotary shaft 22 is
The drooping portion 30a is immersed in the lubricating oil not only when it is immersed in the lubricating oil in 3 but also when the liquid surface of the lubricating oil exists below the lower end 22b. Then, the lubricating oil can rise through the hanging portion 30a by the capillary phenomenon and be supplied into the storage hole 28 of the rotating shaft 22. Therefore, by such a drooping portion 30a, even if the lubricating oil in the storage tank 23 is consumed and the oil level is lowered, it is possible to refuel, and thus heat generation is reliably prevented,
The safety of driving the horizontal full rotary hook is improved.

(3) The oil core 30 keeps impregnated with the lubricating oil, and since the oil core 30 extends over substantially the entire length of the storage hole 28 formed in the rotary shaft 22, after the rotary shaft 22 once stops. When the rotational driving of the rotary shaft 22 is restarted, the lubricating oil is immediately supplied from the upper part of the oil core 30 through the upper end of the storage hole 28 to the supply path 33 by centrifugal force. That is, when restarting operation, the oil core
The lubricating oil impregnated in 30 moves radially outward and collides with the inner peripheral surface 28a, and an upward component force F1 due to the centrifugal force acts on the lubricating oil and rises, so that the gauge oil immediately after restarting the operation. groove
Lubricating oil will be supplied to 21a. Thus track 21a
It is possible to mitigate fluctuations in the amount of lubricating oil supplied to the rail groove 21a and prevent a period in which the lubricating oil is not supplied to the track groove 21a.

(4) Moreover, according to the present invention, as compared with the technique described with reference to FIG. 3 described above, a gear pump is not required and the configuration is simplified.

[Brief description of drawings]

FIG. 1 is a sectional view showing a part of a high-speed horizontal full-rotation rotary hook of an industrial sewing machine according to an embodiment of the present invention, and FIG. Figure 3 is a cross-sectional view of one proposed technique. 21 ... Outer hook, 21a ... Rail groove, 23 ... Rotating shaft, 23 ... Storage tank, 28 ... Storage hole, 28a ... Inner peripheral surface, 30 ... Oil core, 33 ... Supply hole, 35 ...... Adjusting screw

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazuya Suzuki 1-8-2, Kokuryo-cho, Chofu-shi, Tokyo Inside Tokyo Heavy Industries Co., Ltd. (72) Inventor Tadashi Morimoto 2 Sanmei-cho, Abeno-ku, Osaka-shi, Osaka Hirose Manufacturing Co., Ltd. 10-32 (72) Inventor Kiyoshi Nakamura 2-1032 Sanmeicho, Abeno-ku, Osaka City, Osaka Prefecture 10-32 Hirose Manufacturing Co., Ltd. (56) References JP 28-4285 (JP, 28-4285) B1) Japanese Patent Sho 59-9195 (JP, B2) Actual Japanese Sho 30-15440 (JP, Y1)

Claims (1)

[Scope of utility model registration request] 1. A track groove 21 in which a track belt of an inner rotary hook is fitted on an inner peripheral surface.
The outer hook 21 having a formed therein, the rotary shaft 22 coaxially fixed to the outer hook 21 and driven to rotate about the rotation axis l, are arranged near the lower end 22b of the rotary shaft 22, and the lubricating oil is stored. And a storage tank 23 for storing the rotation axis l.
With respect to the storage hole 28 having an inner peripheral surface 28a that extends radially outward with respect to, and having an opening 28b that opens at the lower end 22b protruding into the internal space of the storage tank 23, the storage hole 28 Has a hanging portion 30a extending from the lower end portion 22b of the rotating shaft 22 into the storage tank 23, and accommodates an oil core 30 extending over substantially the entire length of the accommodation hole 28, and the outer hook 21 has a groove groove 21a. A high-speed horizontal full-rotation rotary hook for an industrial sewing machine, characterized in that a lubricating oil supply path 33 is formed to connect the upper end portion of the storage hole 28 with the lubricating oil supply path 33.