Cam mechanism of sewing machine

Abstract

Provided is a cam mechanism of a sewing machine which eliminates oil supply to a contact portion of a driving joint and a driven joint, and can suppress sintering of the contact portion and the like. The cam mechanism (3) includes a first cam member (33, 34) and a second cam member (31, 32), and the first cam member (33, 34) contains 0.6% to 1.3% of carbon in weight %, Iron nitride layers (33b, 34b) are formed on the surface of the first steel material (33a, 34a) that contains 16% to 18% of chromium and has been quenched and tempered; the second cam member (31, 32 ) forming a chromium nitride layer (31b, 32b) on the surface of the second steel material (31a, 32a), and making line contact with the first cam member (33, 34).

Description

technical field [0001] The present invention relates to a cam mechanism of a sewing machine for driving an operating mechanism such as a needle stand mechanism. Background technique [0002] Currently, decorative stitch sewing machines are provided with a needle holder mechanism. This needle stand mechanism has needle stand members sandwiching the machine needles from one side to the other, and these needle stand members are arranged on the lower surface of the needle plate so as to face each other front and back along the cloth feeding direction of the machine needles. And, it is interlocked with the driving of the sewing machine motor as the driving source of sewing and swings in opposite directions, and the needles lowered to the bottom of the needle plate are sandwiched from both sides to receive the needles (for example, refer to Patent Document 1). [0003] A cam mechanism is used as a mechanism for swinging the needle base member, two driving joints are supported on ...

AI Technical Summary

Problems solved by technology

[0008] However, the contact position between the driving joint and the driven joint, such as the sliding part of the eccentric cam and the cam grip arm, in the case of linear contact, although the contact position of the rotating driving joint always changes, but the contact position of the driven joint side The contact parts are in constant contact almost in a fixed place

In the sliding part of such line contact, compared with the surface contact part composed of shafts and bearings, the friction is concentrated in a very narrow range, and it cannot be remedied by conventional sintering and heat generation measures. Friction creates gaps between parts, or causes problems such as sintering, heat generation, etc.

On the other hand, if oil supply is performed as a countermeasure against sintering or heat generation, there will be the following problem: due to the centrifugal force generated by the rotation of the part, the oil will scatter and adhere to the object to be sewn, causing the object to be sewn Quality of Sewn Products Declines

In addition, since the bobbin thread passes around the needle base mechanism, if oil adheres to the bobbin thread, there will be a problem that sewing is performed with the bobbin thread to which the oil is attached, thereby deteriorating the quality of the sewn object.

Images