JP2602072Y2 - Hook oil amount limit oil wick - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a kettle oil amount limiting oil core used in a hook oil supply device for supplying an appropriate amount of oil to a rotary sliding portion of a hook of a sewing machine.

[0002]

2. Description of the Related Art A lower shaft front oil core (hook oil amount limiting oil core) in a sewing machine oil supply device has conventionally been made of wool felt shown in FIG. 5 and sintered copper powder (FIG. 60). -3166
No. 8). And the shape is a columnar shape corresponding to the internal shape of the lower shaft front set screw which is the accommodating portion.

[0003]

Since each of these oil wicks has a very complicated shape of the space between fibers or particles,
The surface tension and the passage resistance of the oil, which block the flow of a small amount of oil, are large, and foreign matter is quickly clogged and the oil cannot flow smoothly.

[0004] Incidentally, the kettle oil amount limiting oil wick has a filter function of removing foreign substances contained in the supplied oil and an adjusting function of reducing the fluctuating pressure of the supplied oil to keep it constant. In particular, in the oil core made of a sintered body of copper powder shown in FIG. 6, foreign substances are less likely to adhere to the surface of the oil core and migrate to the inside, and both functions are immediately reduced. In addition, to improve the oil refueling adjustment function, the density (porosity)
In this case, clogging is likely to occur and the filter function is reduced, and it is difficult to achieve both functions.

In the conventional oil core, it takes more than 30 seconds until the operation of the sewing machine is restarted to reach an appropriate amount of stable oil, which is not preferable. In the first place, the oil core for the kettle oil amount limit,
It has the function of buffering the oil flow and finely adjusting the oil supply to the hook race surface by the surface tension inside the oil core. However,
At the beginning of the re-operation after the sewing machine has been stopped for a while, the pump effect of the shuttle is small, so that it cannot overcome the buffer resistance of the oil core for limiting the oil amount of the shuttle, and the oil cannot easily pass through the oil core. Therefore, as described above, it takes a long time for an appropriate amount of oil to reach the hook race surface. For this reason, at the beginning of the rotation of the shuttle, the shuttle race surface is in a non-lubricating state, and there is often a problem of abrasion of the shuttle race surface, and eventually burning.

[0006] This invention is intended to improve the oil permeability of a kettle oil amount limiting oil wick, and more particularly, to improve both the filter function and the oil supply control function of a kettle oil amount limiting oil wick, and to a sewing machine. The aim is to improve the refueling response at the start of operation.

[0007]

In order to achieve the above-mentioned object, the oil core of the present invention is limited to fine plastic particles.
And the oil outlet portion is beveled in a tapered shape.

[0008]

[Action] In the oil wick having the above configuration, since the surface of the plastic fine particles to be bonded is smooth, the surface tension for preventing the flow of a small amount of oil and the passage resistance of the oil are reduced. As a result, the foreign matter flows easily, and the foreign matter is absorbed as a whole. In addition, since the oil outlet is beveled in a tapered shape, an appropriate amount of lubrication is made immediately in response to the rotation of the outer hook, almost without receiving the buffer resistance of the oil core at the start of the operation of the sewing machine. Even if the specified value is reached,
When the oil in the interior collides with the wall surface of the chamfered portion, the forward vector decreases, and the supplied oil amount does not change.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring to FIGS.

[0010] The oil core for limiting the amount of oil in the kettle is made of a sintered body of fine particles of plastic and has a chamfered portion 9a formed at the oil outlet. Will be described.

In the shuttle oil supply device, an oil passage 4 communicating with the shuttle oil supply pipe 3 is formed in the lower shaft front metal 2 supporting the lower shaft 1.
An oil passage 5 communicating with the oil passage 4 of the lower front metal 2 is formed on the lower shaft 1, and an outer hook 6 fixed to the tip of the lower shaft 1 communicates with the oil passage 5 of the lower shaft 1, and an inner hook 7. An oil passage 8 is formed so as to open so as to be in contact with the race surface 7a of the lower shaft 1. At the end of the oil passage 5 of the lower shaft 1, a hook oil amount limiting oil core (a lower shaft front oil core) 9 is attached. The shuttle felt 10 is mounted near the end of the oil passage 8. In addition, 11 is a thrust bearing of the lower shaft 1, and 12 is
The lower shaft front set screw 13 is an oil amount adjusting screw for adjusting the amount of oil discharged from the oil passage 4 of the lower shaft front metal 2.

In this hook oil supply device, oil discharged from an oil supply pump (not shown) is supplied to an oil passage 4 of the lower shaft front metal 2.
And a part of the oil is adjusted and discharged by the oil amount adjusting screw 13, but the rest flows into the oil passage 5 of the lower shaft 1 and reaches the hook oil amount limiting oil wick 9. Then, when the oil passes therethrough, the pressure is reduced, and the oil advances through the oil passage 8 to the tip of the outer hook 6 by the centrifugal force due to the rotation of the outer hook 6 (pump effect of the hook) to supply the oil to the inner hook race surface 7a. The heat generation, abrasion and seizure of the race surface 7a are prevented.

[0013] The plastic sintered body constituting the pot oil amount limiting oil core 9 has a particle shape such as a sphere or an ellipsoid of 50 to 30.
Fine particles (which may have some irregularities) made of a thermoplastic synthetic resin such as a polyethylene resin having a size of 0 μm are bonded by heating. This plastic sintered body is
The porosity is 40-70%, and as shown in FIG. 1, the surface of the bound fine particles is much smoother than that of the copper sintered body, probably due to the melting of the resin. FIG.
And the copper sintered body shown in FIG. 6 have the same particle diameter and porosity.

[0014] When a sewing machine was operated by forming a kettle oil amount limiting oil core 9 having a length of 10 to 30 mm with a plastic sintered body having such a structure, clogging did not occur even after 2,000 hours or more. We were able to refuel properly. ―
Those made of a conventional copper sintered body clogged after 200 hours of operation. As described above, the reason why the clogging occurrence time can be greatly delayed is that the surface tension and oil passage resistance for preventing the flow of a small amount of oil are reduced due to the smooth bonding surface of the fine particles, and foreign matter is reduced. This is because the foreign matter is not easily clogged in the vicinity of the oil inlet unlike the conventional one, and the foreign matter can be absorbed by the entire oil core. In other words, the oil wick of the present invention has a filter function as a whole oil wick,
This is effective when the oil supply pressure is low. In addition, even if the foreign matter enters the inside of the shaft core, the foreign matter cannot jump out overcoming the surface tension of the oil.

In addition, since the oil core with the oil amount limited in the hook can reduce the density freely due to the easy flow of foreign matter, an oil core structure suitable for the mechanism of the oil supply unit can be adopted. Function can be greatly improved.

Further, the proper rotation width by the oil amount adjusting screw 13 is 0.3 to 1.0 rotation in the conventional one, but it is 2.45 rotation in the oil limiter of the present invention. 2.
It spreads 5 to 8 times, making it easier to adjust.

The oil wick with a limited amount of oil described above has a uniform density, but the density is increased on the oil inlet side so that foreign matter is less likely to accumulate, and a large amount of foreign matter is absorbed at an appropriate place. In addition, it is also possible to make the density appropriately small at the outlet side to surely lower the oil pressure and to keep the flow rate constant.

In the prior art, the hook oil amount limiting oil wick 9 has a columnar shape corresponding to the internal shape of the lower shaft front set screw 12 as described above. A part is cut off to form an oil reservoir 14 between the lower shaft front set screw 12 and the shuttle oil amount limiting oil core 9.

When the oil sump 14 is formed as described above, the oil in the oil sump 14 immediately receives the rotation of the outer hook 6 due to the start of the operation of the sewing machine without substantially receiving the buffer resistance of the oil core, as shown in FIG. It moves in the direction of the arrow and flows out to the race surface 7a of the inner hook 7 by the pump effect of the hook. The time required to reach the appropriate amount of stable oil is much shorter than that of the conventional machine, as is apparent from FIG. 4 showing the oil supply response when the sewing machine is operated at 4000 times / minute.

In addition, when the way of cutting off the oil outlet of the hook oil amount limiting oil wick 9 is tapered, there are particularly the following advantages.

That is, the oil which has the hydraulic pressure vector B, receives the rotation vector A of the lower shaft 1 and moves with the motion vector C,
After hitting the wall surface of the chamfer 9a, the vector angle decreases and the forward vector D decreases (compare with the vector D 'in FIG. 3). This effect increases as the rotational speed increases. Therefore, it is possible to suppress fluctuations in the amount of supplied oil due to fluctuations in the number of rotations in combination with the pump effect of the shuttle.

Instead of cutting a part of the oil outlet of the hook oil amount limiting oil wick 9, the inner peripheral wall corresponding to the oil outlet of the hook oil amount limiting oil wick 9 in the lower shaft front set screw 12 is expanded. Alternatively, an oil reservoir may be formed, and in that case, the same effect can be expected.

[0023]

[Effects of the Invention] The present invention is configured as described above, and has the following effects.

That is, the clogging time can be greatly delayed as compared with the conventional one. In other words, both the filter function and the shuttle oil supply adjusting function can be greatly improved, and the pump effect of the shuttle can be fully utilized. This is particularly effective when the oil supply pressure is low. Further, since foreign matter easily flows, the oil core structure suitable for the mechanism of the hook oil supply device can be adopted by freely lowering the density, and its function can be greatly improved. Further, the appropriate rotation width of the oil amount adjusting screw is increased to about eight times that of the conventional one, and the adjustment is facilitated. In addition, since the surface of the oil core is smooth, it can be easily inserted into the lower shaft front set screw. It should be noted that clogging in the pot felt can also be delayed by using such a plastic sintered body in the pot felt.

If the oil outlet of the oil limiter is tapered, oil can be supplied immediately in response to the rotation of the outer hook when the sewing machine starts operating. In addition, even if the rotation of the outer hook increases, the amount of supplied oil does not change.

[Brief description of the drawings]

FIG. 1 is a sectional view of a kettle oil amount limiting oil wick of the present invention.

FIG. 2 is a sectional view of a shuttle oil supply mechanism.

FIG. 3 is a cross-sectional view showing a relationship between a hook oil amount limiting oil core of the present invention and a lower shaft front set screw.

FIG. 4 is a graph showing refueling responsiveness.

FIG. 5 is a sectional view of a conventional oil core made of wool felt.

FIG. 6 is a sectional view of a conventional oil core made of a sintered body of copper powder.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Lower shaft 2 Lower shaft front metal 3 Hook oil supply pipe 4 Oil passage 5 Oil passage 6 Outer hook 7 Inner hook 8 Oil passage 7a Race surface 9 Lower shaft front oil core 9a Chamfered portion 10 Hook felt 13 Oil amount adjusting screw 14 Oil reservoir

 ──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-52-101122 (JP, A) JP-A-62-142629 (JP, A) JP-B-62-61605 (JP, B2) Jiko-Sho 60- 31668 (JP, Y2) "Iwanami Physical and Chemical Encyclopedia 4th Edition" Iwanami Shoten, published October 12, 1987, p.605

Claims (1)

(57) [Scope of request for utility model registration] 1. An oil wick having a kettle oil amount limitation made of a sintered body of plastic fine particles and having an oil outlet portion chamfered in a tapered shape.