JP2004000773A - Lubricating oil recovery system of sewing machine - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lubricating oil recovery system of a sewing machine that can solve a problem that lubricating oil on a needle bar is sucked by a bearing with the vertical motion of the needle bar and scattered to stain a cloth to be sewed and efficiently recovers the lubricating oil so as not to cause any trouble even when the lubricating oil is sucked together with air. <P>SOLUTION: A jet pump 7 is joined to an oil feed pipe 6 connected to a trochoid pump 3. The jet pump 7 has a passage 22 equipped with a nozzle portion 22a, a throat portion 22c and a diffuser portion 22b, and an oil discharge pipe 18 opened on a cloth feeding side under a bearing 12, through which a needle bar 15 penetrates, is connected to an oil discharge tube connection part 18a communicating with the throat portion 22c. The lubricating oil flowing out to the needle bar 15 is sucked by pressure oil passing through the passage 22 mixed with the pressure oil passing through the passage 22 and jetted into the machine from the diffuser part 22b. The amount of the lubricating oil sucked from the oil discharge pipe 18 is increased by making the nozzle part 22a and the oil discharge tube connection part 18a form an acute angle with the extension of the diffuser part. <P>COPYRIGHT: (C)2004,JPO

Description

The present invention relates to a device for collecting lubricating oil supplied to a movement mechanism of a sewing machine, and more particularly to a device for collecting lubricating oil supplied to a needle bar.

Industrial sewing machines generally have an oil reservoir and oil supply pump below the bed to forcibly lubricate the rotating and sliding parts of the movement mechanism to prevent heat generation and wear of each part. They are run down or forcibly recovered and returned to the sump.

In Patent Literature 1, an oil immersion felt is provided in a bearing through which the needle bar penetrates as oil for the needle bar, and a needle bar protruding from the bearing faces an oil drain pipe connected to an oil feed pump, and is passed through the oil drain pipe. There is disclosed an apparatus in which the tip of an oil core is brought into contact with the oil core and the lubricating oil flowing out of the bearing is forcibly collected by an oil supply pump. Patent Literature 2 discloses a sewing machine that drains oil in a hollow head that supports a needle bar by a pump action of a jet pump of a fueling device and a siphon action of an oil drain pipe connected to the pump.
No. 6-10955 JP-B-38-25489

The lubricating oil adhering to the needle bar protruding from the bearing is handled at the bearing end and scatters around as the needle bar moves up and down, and contaminates the fabric being sewn. In this regard, in the apparatus disclosed in Patent Document 1, the above problem does not occur because the lubricating oil flowing to the needle bar protruding from the bearing is forcibly collected, but the oil supply pump may draw air together with the lubricating oil.
SUMMARY OF THE INVENTION It is an object of the present invention to provide a sewing machine oil recovery device that can prevent a problem from occurring even when lubricating oil flowing out to a needle bar protruding from a bearing is sucked together with air and that can efficiently recover oil. Things.

According to the first aspect of the present invention, an oil supply pump driven from a main shaft via a worm gear, an oil supply pipe connected to a discharge port of the oil supply pump 3, and an upstream side connected to the oil supply pipe via a distributor. Nozzle portion, a downstream diffuser portion connected to the nozzle portion via a throat portion, and a jet pump comprising an oil drain pipe connection portion communicating with the throat portion side of the diffuser portion, and a jet pump comprising: The lubricating oil of the sewing machine that supplies lubricating oil to the oil jet pipe and the jet pump and supplies the lubricating oil discharged from the oil pipe to the needle bar drive mechanism and collects the oil by the jet pump. An oil drainage pipe connected to the oil drainage pipe connection part is provided on the lower side of the bearing through which the rod penetrates, and the other end is connected to the oil drainage pipe connection part. The nozzle part and the diffuser part are bent at an obtuse angle, and the extension of the diffuser part and the nozzle part With And the acute angle formed between the extension and the oil discharge pipe connecting portion of the diffuser, respectively, lubricating oil ejected from the opening of the diffuser portion end is characterized in that as sprayed with the worm gear.

According to the present invention, the oil drained to the needle bar projecting from the bearing due to the negative pressure at the throat is sucked and collected through the oil drain pipe.

Further, according to experiments by the present inventors, when the angle formed by the extension of the diffuser portion and the nozzle portion and the oil drain pipe are made acute, the oil drain pipe has an acute angle as compared with the case where the diffuser portion and the nozzle portion are straight. It was confirmed that even if they were connected and the rotation speed was the same, the amount of lubricating oil suctioned increased, and oil recovery could be performed efficiently.

According to the present invention, since the lubricating oil flowing out to the needle bar protruding from the bearing is collected, the lubricating oil on the needle bar is handled by the bearing as the needle bar moves up and down, thereby contaminating the fabric being sewn. The problem is solved, and even if the air is sucked in along with the lubricating oil through the oil drain pipe, it is only released into the air inside the machine, so that there is no problem, and it is ejected from the diffuser section. The lubricating oil has effects such as being able to be sprayed to the worm gear and flowing down into the oil reservoir, and being able to efficiently suck the drain oil.

1 to 3, a trochoid pump 3 as an oil supply pump is installed in a lower oil reservoir 2 of the overlock sewing machine 1, and is driven from a main shaft 4 via a worm gear 5 to suck lubricating oil from the oil reservoir 2. The oil is supplied to the joint 6A through the oil supply pipe 6. The lubricating oil supplied to the joint 6A is distributed into three parts. One of the distributed lubricating oils is supplied to various mechanisms of the sewing machine bed, and the other two are supplied to the oil jet pipe 6C and the jet pump 7 via the distributor 6B.

(4) The lubricating oil discharged from the oil jet pipe 6C is supplied to various mechanical units of the sewing machine including the needle bar driving mechanism. The needle bar drive mechanism is disposed in the head 8 shown in FIG. 3 and penetrates a needle swing crank 11 fixed to a crankshaft 9 that swings in conjunction with the main shaft 4 and a bearing 12, and is attached to a central portion. The needle bar holder 11a is connected to the needle swing crank 11, and includes a needle bar 15 which moves up and down by swinging of the needle swing crank 11. An opening is formed around the needle bar 15 in the upper part of the bearing 12 through which the needle bar 15 penetrates, and lubrication oil spouted from the oil injection pipe 6C is supplied to the opening of the upper part of the bearing 12 to supply oil to the needle bar. This is performed by impregnating the attached fuel cord 6a. The oil discharged after being supplied to the needle bar drive mechanism is returned to the oil reservoir 2 through the oil discharge hole 16.

The bearing 12 also has an opening formed on the lower side of the cloth feed-out side, and an oil drain pipe 18 connected to the jet pump 7 and passing through the machine frame of the sewing machine is opened near this opening. As shown in FIG. 4, the jet pump 7 includes an upstream nozzle portion 22a and a downstream diffuser portion 22b, and the nozzle portion 22a communicates with a throat portion 22c of the diffuser portion 22b and is bent at an obtuse angle with the diffuser portion. The flow path 22 is formed, and the end of the diffuser portion 22 b is open toward the worm gear 5. The oil supply pipe 6 is connected to the nozzle part 22a via the distributor 6B, and the oil drain pipe connection part 18a communicates with the throat part 22c side of the diffuser part 22b, and the oil drain pipe 18 is connected. . As shown in FIG. 4, the oil pipe connecting portion 18a forms an acute angle with the extension β of the diffuser portion 22b downstream of the throat portion 22c and the angle β formed by the extension of the diffuser portion 22b and the nozzle portion 22a. I have.

The operation of the jet pump 3 is such that when the pressure oil fed by the oil supply pump 3 is jetted from the nozzle 22a, the pumping action generated at the oil drain pipe connection portion 18a sucks the air from the oil drain pipe 18 and the lubricating oil flowing out of the bearing 12. , At the throat part 22c. The lubricating oil ejected from the diffuser portion 22b is sprayed on the worm gear 5 and flows down into the oil reservoir 2. In addition, even if air is sucked together with the lubricating oil through the oil drain pipe 18, the air is discharged from the outlet of the flow path 22 together with the pressure oil, so that no trouble occurs.

Example 1
An oil drain pipe using a jet pump 7 having an angle α of 20 ° and an angle β of 20 ° as shown in FIG. 4, a rotation speed of the sewing machine of 2000 rpm, and a discharge amount of pressure oil from the jet pump 7 of 320 ml / min The suction rate from No. 18 was 2.9 ml / min, the rotational speed was 4000 rpm, and the discharge rate of the pressure oil was 530 ml / min, and the suction rate was 5.8 ml / min.

Example 2
Using a jet pump 7 having an angle α of 30 ° and an angle β of 20 ° shown in FIG. 4, the amount of suction from the oil drain pipe 18 when the rotation speed of the sewing machine is 2000 rpm and the discharge amount of pressure oil is 350 ml / min. Was 3.1 ml / min, the number of revolutions was 4000 rpm, and the suction amount was 5.9 ml / min when the discharge amount of pressure oil was 580 ml / min.

Comparative Example A suction port from the oil drain pipe 18 when the rotation speed of the sewing machine is 2000 rpm and the discharge amount of the pressure oil is 450 ml / min using the jet pump 7 in which the angle α shown in FIG. Was 1.7 ml / min, the number of revolutions was 4000 rpm, and the suction amount was 2.5 ml / min when the discharge amount was 580 ml / min.
The above results are shown in Table 1 below.

As can be seen from the above results, in the jet pumps 7 of Examples 1 and 2 in which the angle α was made an acute angle of 20 ° or 30 ° and the angle β was made an acute angle of 20 °, the angle α was an acute angle of 30 °. However, as compared with the jet pump 7 of the comparative example in which the angle β was 0 ° and the flow path 22 was straight, the suction amount could be increased even if the discharge amount of the pressure oil was small.

FIG. 2 is a front view showing a cross section of a main part of the overlock sewing machine. FIG. 2 is a right side view showing a cross section of a main part of the overlock sewing machine. The same left view. The enlarged view of the flow path of a jet pump.

Explanation of reference numerals

1. Overlock sewing machine 2. Oil reservoir 3. Trochoid pump 4. Main shaft 5. Worm gear 6, 6a. Oil supply pipe 7. Jet pump 8. Head 9. Crank shaft 11. Crank 12.・ ・ Bearing 15 ・ ・ Needle bar 16 ・ ・ Oil supply hole 18 ・ ・ Drain pipe 22 ・ ・ Flow path 22a ・ ・ Nozzle 22b ・ ・ Diffuser part 22c ・ ・ Throat part

Claims (3)

A refueling pump driven from a main shaft via a worm gear, a refueling pipe connected to a discharge port of the refueling pump, an upstream nozzle connected to the refueling pipe via a distributor, and A jet pump comprising a downstream diffuser portion connected via a throat portion and an oil drain pipe connection portion communicating with the throat portion side of the diffuser portion, and lubricating oil is supplied to the oil pipe and the jet flow via a distributor. In addition to supplying oil to the pump, the lubricant oil released from the oil pipe is supplied to the needle bar drive mechanism, and the oil recovery device of the sewing machine that collects oil by the jet pump.
One side is provided with a drainage pipe connected to the drainage pipe connection part, and the other side is opened on the cloth delivery side below the bearing through which the needle bar passes,
The nozzle portion and the diffuser portion are bent at an obtuse angle, and the angle between the extension of the diffuser portion and the nozzle portion, and the angle between the extension of the diffuser portion and the drain connection portion are each made an acute angle,
A lubricating oil collecting device for a sewing machine, wherein lubricating oil ejected from an opening at an end of a diffuser portion is blown to a worm gear. 2. The lubricating oil collecting device for a sewing machine according to claim 1, wherein the angle between the extension of the diffuser portion and the nozzle portion is 20 °, and the angle between the extension of the diffuser portion and the oil drain connection portion is 20 ° to 30 °. The lubricating oil collecting device for a sewing machine according to claim 1, wherein the oil supply from the oil injection pipe to the needle bar is performed by an oil supply cord attached to an opening at an upper part of the bearing.

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