JPH07265573A - Oil volume limiting member in sewing machine - Google Patents

Abstract

PURPOSE:To facilitate the adjustment for the quantity of lubricating oil by forming at least one corner part in the upstream part of an oil volume limiting member which is located in a lubricating oil passage in a lower shaft supporting at its one end a rotating hook, for rotating the latter, as viewed in the direction of the flow of the lubricating oil. CONSTITUTION:In a full rotation hook structure, a lower shaft 1 is rotated at a high speed together with a rotating hook so that lubricating oil is fed at a high flow rate into a first lubricating oil passage 4 from a pump. An oil volume limiting member 26 provided in the passage 4, gives a resistance to the lubricating oil so that the pressure and the volume of the oil are limited. In this case, the oil limiting member 26 is composed of an oil limiting member body 26A, and a large diameter part 26B having a diameter larger than that of the body 26A and connected to the same. The rotation of the limiting member 26 causes the lubricating oil concentrated in a corner part between the body 26A and the large diameter part 26B to be jetted in a disc-like shape, thereby it is possible to effectively induce a resistance given to the flow of the lubricating oil.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a sewing machine having a high rotational speed such as an industrial sewing machine, in which an oil amount limiting member main body is provided in a lubricating oil passage of a lower shaft which supports an outer hook at an end portion thereof and is rotationally driven. The present invention relates to an oil amount limiting member of a sewing machine which is arranged so as to substantially fill a passage, and particularly relates to improvement of an end face shape of a main body of the oil amount limiting member.

[0002]

2. Description of the Related Art In such an industrial sewing machine, since the needle reciprocates at a maximum of about 5,500 times per minute, a hook mechanism or the like which performs an operation related to the operation of the needle has a maximum of 110.
It will rotate about 00 times. Therefore, unless the lubricating oil is forcibly supplied to the bearings at such high speeds by the pump, the members may be overheated and seized or worn.

By the way, in a sewing machine, a full-rotary hook structure, which comprises the lower shaft, an outer hook and an inner hook for accommodating a bobbin supported inside the outer hook, generally hooks a lower thread on an upper thread passing through a needle. Since the inner hook that holds the bobbin that winds the lower thread is stationary despite the reciprocating motion of the needle, the outer hook that has the hook for hooking the upper thread It will rotate at high speed in association with the reciprocating motion of the needle.

Therefore, lubricating oil must be supplied to the sliding surface of the inner hook which relatively slides on the outer hook.
This lubricating oil is conventionally supplied from the lubricating oil passage formed in the lower shaft supporting the outer pot to the race surface of the inner pot through another lubricating oil passage formed in the outer pot. It was. First, a general structure of such a full rotary hook in a sewing machine will be described with reference to FIG.

In FIG. 5, a lower shaft 1 which is rotated at a high speed by a driving means such as a motor (not shown) is provided, and the lower shaft 1 is provided with a pair of metals 2 (which are provided at intervals in the axial direction). Axial movement is restricted and supported by a thrust receiver 3 incorporated in only one of them). A first lubricating oil passage 4 extending in the axial direction is formed in the center of the lower shaft 1, and the first lubricating oil passage 4 is lubricated from the base end side of the lower shaft 1 (not shown). It is possible to supply oil.

An outer hook 5 is fixed to the tip of the lower shaft 1. The outer pot 5 is composed of a disc-shaped base portion 6 fitted to the outer periphery of the tip portion of the lower shaft 1 and a substantially cylindrical outer pot main body 10 that is connected to the tip end side of the base portion 6. The base 6 is provided with a central hole 7 into which the tip end of the lower shaft 1 can be inserted relatively densely. Further, the base portion 6 is formed with a radial screw hole 8 that communicates with the central hole 7 from the outer peripheral surface 6 a thereof.
The outer pot 5 can be rotated integrally with the lower shaft 1 by screwing the screw 9 into the lower shaft 1 and pressing the tip of the screw 9 against the outer peripheral surface 1 a of the lower shaft 1.

The outer pot main body 10 is composed of a base plate 11 having a diameter larger than that of the base portion 6 and a substantially cylindrical outer peripheral wall 12 connected to the tip end side of the base plate 11.
A relatively thin hook member 13 is attached to the outer peripheral surface 12a by a screw (not shown). Further, the outer pot 5
An annular guide groove 14 is formed on the circumferential surface of the outer peripheral wall 12.

In the inner space 15 of the outer pot 5, an inner pot 16 which is rotatable relative to the outer pot 5 is arranged. The inner pot 16 is formed into a substantially cylindrical shape as a whole, and is fitted into the guide groove 14 of the outer pot 5 on the outer peripheral surface 16a of the inner pot 16 and relatively slidably in the circumferential direction. A substantially annular guide protrusion 17 is provided around the thread except for the portion where the thread comes out. A support plate 18 provided in the linear direction is integrally attached to the base end portion of the inner pot 16, and the inner pot 16 is provided at the center of the support plate 18 in the longitudinal direction.
The support pins 19 extending in the axial direction of are provided on the same axis. A bobbin (not shown) in which a lower thread is wound is attached to the support pin 19.

A circular concave portion 20 communicating with the central hole 7 and having a diameter larger than that of the central hole 7 is formed in the substrate 11 of the outer hook main body 10 of the outer hook 5. The second lubricating oil passage 21 in the shuttle 5 communicates. The second lubricating oil passage 21 is formed in the substrate 11 so as to extend substantially in the radial direction, and is communicated with the radial passage 22 communicating with the circular recess 20 and the outer end of the radial passage 22. To the outer peripheral wall 12 and is formed by an axial passage 23 formed so as to extend substantially in the axial direction.

The tip of the axial passage 23 has the guide groove 1
4 reaches the vicinity of the outer peripheral wall 1
A circular filtration chamber 24, which communicates with the guide groove 14 and the axial passage 23, is formed in the inside 2. In addition,
The filtration chamber 24 is open to the outer peripheral surface 12a of the outer peripheral wall 12 and is covered with a lid (not shown). The filtration chamber 24 accommodates a filtration member in which fibers made of felt or the like are hardened like a non-woven fabric.

On the other hand, an oil amount limiting member 26 for limiting the oil amount is attached to the tip of the lower shaft 1, and the oil amount limiting member 26 actually limits the oil amount.
And a holding sleeve that holds the oil amount limiting member body 26A.
It is made up of a sleeve 27. This holding sleeve 27 is
A sleeve main body 28 having a screw portion, which is formed on the outer peripheral surface, which is screwed into a screw portion (not shown) formed on the inner peripheral surface forming the first lubricating oil passage 4 of the lower shaft 1, and is connected to the sleeve main body 28. A flange 29 having a diameter larger than that of the first lubricating oil passage 4 is provided, and a communication hole 30 that connects the inside of the sleeve body 28 and the circular recess 20 is formed in the flange 29. Inside the sleeve main body 28, a recess 31 is formed which communicates with the communication hole 30 and has a truncated cone shape with a small radius on the communication hole 30 side. And the sleeve body 28
The oil amount limiting member main body 26A mounted inside is made of a porous sintered body, and has a cylindrical shape that is substantially equal to the inner diameter of the sleeve main body 28.

The following actions can be obtained in the full-rotary hook structure described above. That is, the lower shaft 1 is attached to the outer hook 5
At the same time, it rotates at a high speed, and while sewing is performed with a needle (not shown), lubricating oil is supplied at high pressure into the first lubricating oil passage 4 of the lower shaft 2 by a pump (not shown). Normally, it is necessary to supply a large amount of high-pressure lubricating oil to the other high-speed sliding parts other than the full-rotation hook structure, but in this full-rotation hook structure, the high-pressure lubricating oil remains as it is.
If it is sprayed from the guide groove 14 of No. 2, the cloth or the like being sewn will be soiled with the lubricating oil. Therefore, an oil amount limiting member 26 is provided in the first lubricating oil passage 4, and the resistance of the oil amount limiting member body 26A when the lubricating oil passes through the oil amount limiting member body 26A of the oil amount limiting member 26. As a result, the oil pressure and the oil amount of the lubricating oil passing through the oil amount limiting member main body 26A are reduced. Then, when passing through the radial passage 22 of the outer pot main body 10 which is rotating at a high speed, the lubricating oil is accelerated to some extent by centrifugal force, and an appropriate amount of lubricating oil is supplied from the guide groove 14 of the outer pot 5 to the inner pot. It is supplied to 16 guide protrusions 17.

[0013]

By the way, the conventional mechanism for supplying the lubricating oil from the pump to the first lubricating oil passage 4 is as follows.
As shown in FIG. 6, a lubricating oil supply passage 32 whose upstream side communicates with a pump (not shown) in the metal 2 and one of the downstream side branches of the lubricating oil supply passage 32 communicate with the first lubricating oil passage 4. The other end of the drain passage 33 is formed with a drain passage 33 communicating with an oil reservoir (not shown), and an adjusting screw 34 capable of adjusting the opening area of the drain passage 33 is provided on the metal 2 so as to be able to move forward and backward.

The opening area of the drain passage 33 is adjusted by turning the adjusting screw 34 to indirectly adjust the amount of oil supplied to the first lubricating oil passage 4 and the hydraulic pressure.
Therefore, when operating the sewing machine at high speed, it is necessary to supply the lubricating oil from the lubricating oil supply passage 32 to the first lubricating oil passage 4 against the centrifugal force due to the high speed rotation of the lower shaft 1 as shown by the arrow. Therefore, the lubricating oil was supplied from the pump to the first lubricating oil passage 4 through the lubricating oil supply passage 32 at a considerably high pressure.

However, if the hydraulic pressure of the pump is increased,
The supply amount of the lubricating oil in the first lubricating oil passage 4 also increases. Here, since the upstream end surface 26a of the oil amount limiting member 26 in the first lubricating oil passage 4 in the lubricating oil flowing direction is formed into a circular flat surface orthogonal to the flowing direction, the oil amount limiting member 26 The shape of the upstream end surface 26a does not affect the flow of the lubricating oil so much that the lubricating oil easily passes through the oil amount limiting member main body 26A of the oil amount limiting member 26 and the second lubricating oil passage 21 of the outer pot 5. Since the oil flows in the direction, the amount of oil supplied from the guide groove 14 of the outer hook 5 becomes large, and the cloth to be sewn may be soiled. For this reason, adjustment of the supply amount of lubricating oil due to fluctuations in the rotational speed of the pump is delicate and the adjustment range is narrow.
It was hard to adjust.

The present invention solves the above problems in the conventional oil amount limiting member, widens the adjustment range of the lubricating oil to be supplied, and facilitates the adjustment of the lubricating oil supply amount. It is intended to provide a member.

[0017]

SUMMARY OF THE INVENTION In order to solve the above problems, the present invention substantially fills the passage with a main body of an oil amount limiting member in a lubricating oil passage of a lower shaft which supports an outer pot at its end and is driven to rotate. In the oil amount limiting member of the sewing machine arranged in such a manner, the oil amount of the sewing machine is provided with a shape in which at least one corner portion is provided in the upstream side portion of the oil amount limiting member main body in the direction in which the lubricating oil flows. Adopted a restriction member.

[0018]

With the configuration of the present invention, the lubricating oil that collects at the corners is jetted onto the disk due to the rotation of the oil amount limiting member main body, so that the flow of the lubricating oil flowing near the outer periphery in the oil amount limiting member main body is resisted. Therefore, the amount of refueling is limited, and the increase in the amount of refueling is reduced by the increase in centrifugal force that accompanies the increase in rotation in the body of the oil amount limiting member.

[0019]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below with reference to the embodiments shown in the drawings. FIG. 1 is a diagram showing a first embodiment of the present invention. In this embodiment, the oil amount limiting member main body 26A of the oil amount limiting member 26 is provided with a large diameter portion 26B having a diameter larger than that of the base portion, and the upstream end face 26a intersects perpendicularly to the lubricating oil flowing direction to win. It is formed in a circular flat shape. The oil amount limiting member body 26A is made of a porous sintered body.

Next, the following operation is obtained by the configuration of the first embodiment. That is, when the amount of oil is small, the flow of the lubricating oil in the first lubricating oil passage 4 flows only outside the first lubricating oil passage 4 due to centrifugal force as shown by an arrow x in FIG. On the other hand, when the number of rotations increases and the amount of oil increases, as shown by y in FIG. 2, a portion slightly closer to the central axis of the first lubricating oil passage 4 also flows, and The lubricant flows through the holes to the downstream side in the flow direction. On the other hand, a part of the lubricating oil that has entered the oil amount limiting member main body 26A flows in the outer peripheral direction due to the centrifugal force, but in that case, the surface tension of the lubricating oil causes the lubricant oil to collect at the corners 26b and contain a large amount of lubricating oil. In addition, due to centrifugal force, the large diameter portion 26
The lubricating oil is scattered from the corner portion 26b of B toward the outer peripheral direction of the first lubricating oil passage. As a result, in the first lubricating oil passage 4, the flow of the lubricating oil is resisted by the scattered lubricating oil, and the amount of oil passing through the oil amount limiting member main body 26A is smaller than when the lubricating oil flow is laminar. To do. Therefore, the adjustment range of the amount of lubricating oil supplied to the race surfaces of the outer pot and the inner pot can be widened to facilitate the adjustment of the amount of lubricating oil supplied.

Further, the flow of the lubricating oil in the first lubricating oil passage 4 is supplied in a large amount as the rotation speed of a lubricating oil pump (not shown) increases, and is in a proportional relationship. By the way, in a normal industrial sewing machine, since this lubricating oil pump is driven by a sewing machine motor (not shown), the rotational speed of the lower shaft is substantially equal to the rotational speed of this lubricating oil pump. Therefore, the lubricating oil amount increases almost in proportion to the rotation speed of the lower shaft.

On the other hand, the above-mentioned disc-shaped lubricating oil is generated by centrifugal force due to the rotation of the lower shaft. Therefore, the amount of lubricating oil increases substantially in proportion to the square of the rotational speed of the lower shaft. Therefore, when the number of rotations of the lower shaft increases, the lubricating oil suddenly ejected in the form of a disk becomes strong, and the flow of the lubricating oil near the outer peripheral side in the first lubricating oil passage 4 is suddenly suppressed, and Minimize the increase in the amount of lubricating oil supplied to the race surface of the inner hook. For this reason, the change in the proper amount screw position of the supply amount of the lubricating oil is small.

FIG. 3A shows the permissible rotation of the adjusting screw for opening and closing the drain passage for adjusting the oil amount of the lubricating oil in the oil amount limiting member 26 of the first embodiment and the conventional oil amount limiting member 26. It shows the range. That is, when the oil amount limiting member main body 26A of the oil amount limiting member 26 has a cylindrical shape as in the conventional example, the allowable rotation range of the adjusting screw is 50 rpm.
0.4 rpm at 00 SPM, 3000 SP
When M, it is about 1.1 rotations and the allowable rotation range of the adjusting screw is narrow. On the other hand, the allowable rotation range of the adjusting screw of the first embodiment is about 0.9 rotations at a rotation speed of 5000 SPM, and about 1.9 rotations at a rotation speed of 3000 SPM. It is wider than in the case of.
Therefore, the amount of lubricating oil can be easily adjusted.

Further, FIG. 3 (B) shows the proper rotation position of the adjusting screw according to the first embodiment and the conventional adjusting screw. That is, in the case of the conventional example, the proper screw position of the adjusting screw is 5 rotations.
At 000 SPM, about 4.4 rotations, the number of rotations is 3000 S
About 2.3 rotations at PM, the appropriate screw position of the adjusting screw changes significantly. On the other hand, the proper amount screw position of the adjusting screw of the first embodiment is about 3. when the rotation speed is 5000 SPM.
When the number of revolutions is 6 and the number of revolutions is 3000 SPM, the adjustment screw position is about 2.5 revolutions, which is smaller than the conventional example. Therefore, the change in the proper amount screw position of the supply amount of lubricating oil is small.

FIG. 4 is a diagram showing another embodiment of the present invention. (A) is a second embodiment in which the large diameter portion 26B of the first embodiment has a truncated cone shape. (B) shows a third embodiment in which the large diameter portion 26B as shown in the first embodiment is cut in an arc shape. A sectional view of the XX 'portion of this figure (B) is shown in FIG.
Shown in. In this way, the part with a diameter larger than the base part is about 1/4
Two are facing each other.

(D) shows a fourth embodiment in which the large diameter portion 26B of the first embodiment is made smaller than the diameter of the base portion contrary to the second embodiment. (E) shows a fifth embodiment in which a part of the large diameter portion 26B of the first embodiment is made smaller than the diameter of the base portion. Similarly, with respect to the four other embodiments as described above, the lubricating oil collects at many corners provided, and the same effect as that of the first embodiment is obtained.

[0027]

According to the present invention, the following effects can be obtained. (1) In adjusting the amount of oil in the hook, the rotation range of the oil amount adjusting screw that can obtain the optimum amount of oil becomes wider. (2) In adjusting the amount of oil in the hook, even if the number of rotations of the sewing machine increases, the change in the amount of oil supplied to the outer hook can be reduced, and the pump can reliably lubricate other mechanisms.

[Brief description of drawings]

FIG. 1 is a schematic diagram showing a first embodiment of the present invention.

FIG. 2 is a cross-sectional view showing a flow state of lubricating oil in the embodiment of FIG.

FIG. 3 is a diagram showing an allowable rotation range and an appropriate amount screw position of an adjusting screw in the first embodiment and a conventional one.

FIG. 4 is a schematic view showing another embodiment of the present invention.

FIG. 5 is a cross-sectional view showing a general rotary hook structure of a general sewing machine.

FIG. 6 is a sectional view showing an oil amount adjusting structure of lubricating oil in the full rotary hook structure of FIG. 4;

[Explanation of symbols]

 1 Lower shaft 2 Metal 4 1st lubricating oil passage 5 Outer hook 16 Inner hook 21 2nd lubricating oil passage 26 Oil amount limiting member 26A Oil amount limiting member main body 26a Upstream end face 32 Lubricating oil supply passage 33 Drain passage 34 Adjustment screw

Claims (1)

[Claims] 1. An oil amount restricting member for a sewing machine, wherein an oil amount restricting member main body is disposed in a lubricating oil passage of a lower shaft, which is rotatably driven by supporting an outer hook at an end thereof, so as to substantially fill the passage. An oil amount limiting member for a sewing machine, characterized in that at least one corner portion is provided in an upstream side portion of the oil amount limiting member main body in a direction in which lubricating oil flows.