JPH0371920B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for supplying lubricating oil to a rotating rotary rotary hook, and more particularly to a sliding portion of an outer rotary hook.

[Prior Art] As a hook oil supply device for a sewing machine, the one shown in FIG. 3 has been proposed. That is, the rotary shaft 2 of the outer pot 1 is formed with a storage hole 2a having an inner circumferential surface that slopes away from the axial direction as it goes upward, and the lower end of the storage hole 2a is immersed in the lubricating oil in the storage tank 4. be done. An oil wick 3 whose lower end is immersed in the lubricating oil in the storage tank 4 is provided in the storage hole 2a.
is stored.

5 is a first supply hole formed in the bottom 1b of the outer pot 1 and has one end opening above the storage hole 2a; 6 is formed in the side wall 1c of the outer pot 1, and the lower end is connected to the first supply hole 5; A second supply hole communicates with the other end, and its upper end communicates with the raceway 1a of the outer hook to supply lubricating oil to the sliding portion. Reference numeral 6a denotes an oil wick inserted into the second supply hole 6, and 7 an oil amount adjustment screw that contacts the oil wick 6a and changes its cross-sectional area to finely adjust the amount of lubricating oil supplied.

When the rotary shaft 2 of the outer pot 1 is driven to rotate, the lubricating oil in the storage tank 4 is absorbed by the synergistic effect of the penetrating action of the oil wick 3 in the storage hole 2a and the inclined surface of the storage hole 2a. It can be stably supplied to the supply hole.

In addition, the oil amount adjustment screw provided in the middle of the supply path that leads lubricating oil to the raceway 1a of the outer hook 1 allows the outer hook 1 to
The amount of lubricating oil supplied to the track groove 1a can be finely adjusted.

[Problems to be Solved by the Invention] However, in the above-mentioned conventional technology, even if the oil amount adjusting screw is fixed at a constant value, the amount of lubricating oil supplied to the supply point fluctuates greatly, and the amount of supplied lubricating oil varies greatly. If the lubricating oil is too low, the sliding portion will seize; if the lubricating oil is too high, the lubricating oil will scatter from the sliding portion, causing problems such as oil stains on the bobbin thread. The causes of such large fluctuations in the amount of lubricating oil supplied are as follows.

(a) From the oil pan at the bottom of the sewing machine to the storage tank,
Since the supply amount from the plunger pump for supplying lubricating oil constantly fluctuates, the pressure on the lower end surface of the outer rotary shaft, which is immersed in the lubricating oil in the storage tank, fluctuates, so the oil amount is adjusted. Even if the screw is held in a fixed position, the amount of oil supplied fluctuates.

The reason why the amount of oil fed by the plunger pump constantly fluctuates is due to phenomena such as air suction and cavitation during operation, but it is impossible to completely seal the plunger pump to prevent these phenomena.

(b) Since the oil core installed in the storage hole of the rotating shaft is made of thread or felt, it may become clogged with use. When the supply amount increases and clogging progresses, conversely, oil passage becomes poor and the supply amount decreases.

Furthermore, since the oil wick formed of felt etc. gets clogged in a relatively short time, constant monitoring is required to ensure that the supply of lubricating oil at the lubrication point does not become insufficient and cause seizing. Not only is this a hassle, but replacing the oil wick itself also requires extremely complicated work.

[Means for Solving the Problems] This invention provides an oil supply device for a rotating rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary rotary coils. The position of the oil feed path for supplying oil and the level of the stored lubricating oil is kept at a constant height with respect to the open end of the oil feed pipe, and the potential energy causes the lubricating oil to reach the open end of the oil feed pipe. The problem of the above-mentioned prior art is attempted to be solved by constructing the lubricating oil pump with a metering oil feeder that always supplies lubricating oil at a constant pressure.

[Function] In this invention, the oil level of the lubricating oil stored in the metering oil feeder that sends lubricating oil to the open end of the oil pipe is always kept at a constant position higher than the lower open end of the oil pipe. The lubricating oil is delivered to the open end of the oil pipe using its potential energy, and the pressure of the lubricating oil at this open end is always constant.
Therefore, the supply of lubricating oil to the supply location via the oil pipe becomes extremely stable.

[Embodiments of the Invention] Examples of the present invention will be described based on the drawings.

The same reference numerals are given to the same or corresponding parts as in the prior art, and redundant explanation will be omitted.

FIG. 1 is a longitudinal sectional view showing an embodiment of the present invention.

In the figure, 1b is an oil feed passage formed through the bottom 1c and side wall 1d of the outer pot 1, one end of which is connected to the raceway 1a of the outer pot 1, and the other end to the rotating shaft 2 of the outer pot. The oil feed pipes 2a each communicate with an end on the outer hook side.

The oil feed pipe 2 a is formed to have an inner circumferential surface that slopes away from the axial direction toward the outer shell, and a lower open end thereof projects into the oil tank 4 .

Reference numeral 8 denotes a metered oil feeder interposed between the oil tank 4 and a plunger pump for oil feeding (not shown). The metered oil feeder 8 includes a reservoir 8a having an open top, an inlet 8b into which lubricating oil from the plunger pump flows, and an outlet passage 8c.

The outflow path 8c is provided with an adjustment needle 9 as an oil feed rate variable mechanism, which moves back and forth in the horizontal portion of the outflow path 8c to adjust the flow rate of the lubricating oil.

The upper surface of the flow storage section 8a is always open as described above, and the tube 10 attached to the inflow port 8b
The lubricating oil supplied from the plunger pump through the tank overflows so that the oil level is always located at the upper end surface of the reservoir 8a.

Further, the fixed amount oil feeder 8 is provided at an appropriate position so that the upper end surface of the reservoir portion 8a is higher than the lower opening end of the oil feed pipe 2a.

Note that 11 indicates the end of the outflow path 8c and the oil tank 4.
This is a tube that connects the intake port 4a.

Next, the action will be explained.

When the rotary shaft 2 of the outer pot 1 is not rotating, the lubricating oil in the reservoir 8a flows into the oil tank 4 via the outflow path 8c and the tube 11 due to potential energy, and is sequentially fed into the oil feed pipe 2a. After reaching the lower opening end, the oil level in the oil feed pipe 2a rises in the oil feed pipe 2a so that the oil level in the oil feed pipe 2a becomes equal to the oil level in the reservoir 8a, that is, the same height as the upper end surface of the reservoir 8a.

When the rotary shaft 2 of the outer pot 1 rotates, the lubricating oil collides with the inner circumferential surface of the oil feed pipe 2a due to centrifugal force. As described above, this inner circumferential surface has a tapered shape that expands in diameter upward, so the colliding lubricating oil sequentially moves upward along the wall surface, passes through the oil feed path 1b, and passes through the track of the outer pot 1. After reaching the open end of the groove 1a,
Lubricate the required sliding parts.

By the way, the pressure of the lubricating oil at the lower open end of the oil feed pipe 2a is generated by the height difference between the lower open end and the upper end surface of the reservoir 8a. Since the pressure of the lubricating oil flowing into the oil feed pipe 2a is always kept constant, by fixing the position of the adjusting needle 9 as a variable oil feed rate mechanism at a predetermined position, lubricant oil is fed from the oil feed pipe 2a to the track groove 1a. The amount of oil is always constant. Further, since the above potential energy is very small, the flow rate flowing from the storage section 8a to the oil tank 4 is small, but it can be further finely adjusted by the adjustment needle 9 if necessary. In addition, normally, energy at a certain position is always acting, and the storage part 8
Although the lubricating oil in a does not flow into the oil tank all at once, even if a large amount of the lubricating oil in the reservoir 8a flows into the oil tank 4 at once, the horizontal cross-sectional area of the reservoir 8a is Since it is smaller than the area, changes in the oil level within the oil tank 4 are extremely small.

FIG. 2 is a diagram showing another embodiment of the invention.

[Effects of the Invention] As described above, the present invention stores lubricating oil forcibly sent from a pump in a small reservoir and then transfers potential energy to a storage tank having a larger horizontal cross-sectional area than the reservoir. At the same time, the lubricating oil in the storage tank is pulled up by the centrifugal force accompanying the rotation of the oil feed pipe, which has an inner circumferential surface that gradually slopes away from the axis as it moves toward the outer pot. It is configured to supply lubricating oil to the sliding parts, and since the oil level in the storage tank is always maintained at a constant position, it is possible to supply just the right amount of lubricating oil to the sliding parts of the pot. This has the effect of preventing the hook from seizing and improving the operating rate of the sewing machine, and also prevents lubricant from being supplied in excess and scattering around the hook, contaminating the sewing thread and the work being sewn with the lubricant. , it also has the effect of improving sewing quality.

Furthermore, since there is no need for an oil wick in the oil feed pipe provided within the rotary shaft of the outer hook, there is no need to replace the oil wick, which improves sewing efficiency.

[Brief explanation of drawings]

FIG. 1 is a partially omitted vertical cross-sectional view showing an embodiment of the present invention, and FIG. 2 is a vertical cross-sectional view showing a conventional technique. In the figure, 1... Outer hook, 1b... Oil feed path,
2... Rotating shaft, 2a... Oil feed pipe, 8... Fixed amount oil feeder, 8a... Reservoir, 8b... Inflow port, 8c...
Outflow path, 9... Oil amount variable mechanism.

Claims (1)

[Claims] 1. A storage tank 4 that stores lubricating oil, an oil feed pipe 2a that has its lower open end floating above the bottom of the storage tank and supplies the lubricating oil in the storage tank to the sliding part of the outer pot, and the outer pot. an oil feed passage 1 which is formed in and has one end communicating with the raceway of the outer pot and the other end communicating with the oil feed pipe.
b, and a metered oil feeder 8 for storing lubricating oil from a main oil supply pump for forcibly discharging lubricating oil and feeding the lubricating oil to a storage tank, which comprises: The oil feed pipe is formed on the rotating shaft 2 of the outer pot so as to have an inner circumferential surface that gradually slopes away from the axis as it goes toward the outer pot, and the metering oil feeder has a horizontal cross-sectional area equal to that of the storage tank. Reservoir 8 smaller than the horizontal cross-sectional area and open at the top
a, an inlet 8b for lubricating oil into the reservoir, an outlet 8c from the reservoir, and a variable oil feed rate mechanism 9 provided in the outlet 8c. maintain the oil level in the reservoir of the metering oil feeder at a higher position than the lower opening end position of the oil feed pipe so that the lubricating oil overflows;
A sewing machine hook oil supply device characterized by constantly supplying a fixed amount of lubricating oil to an oil feed pipe.