JPH049995Y2 - - Google Patents

Description

[Detailed Description of the Invention] Industrial Application Field The present invention relates to parts of a sewing machine, and more particularly, to the structure of the parts constituting the sewing machine.

BACKGROUND TECHNOLOGY For example, the outer hook of a lockstitch sewing machine is made of a metal material such as iron, and is manufactured by cutting and plastic working.

Problems to be solved by the invention It is clear that productivity is poor with such prior art.

Additionally, this prior art is rigid and therefore prone to wear and deformation due to impact forces when the needles collide.

Furthermore, this prior art produces a lot of noise during sewing.

Another problem with the prior art is that the outer hook has a relatively large weight, so the inertial force during sewing is large, so it takes time to completely stop after sewing is finished, and the outer hook tends to continue rotating due to inertia. There is. Therefore, the quality after sewing is degraded.

In order to solve this problem, it is conceivable to manufacture the outer hook or inner hook from synthetic resin, but if this is done, wear due to friction at the journal part of the sliding bearing and the part that contacts the thread, etc. However, there is a problem that the hook may melt due to the heat generated by the friction.
Therefore, high-speed rotation of the outer hook is impossible, and its life is short. Therefore, it is conceivable to coat the surface of the outer hook or inner hook made of synthetic resin with a material with high hardness such as fluororesin, but in order to form such a coating layer, it is difficult to It takes a long time and therefore, in order not to reduce productivity, it is preferable to form it as thin as possible, and a predetermined thickness that is sufficient to withstand wear must be ensured. Furthermore, if the coating layer is formed in advance to a large thickness in order to ensure a predetermined thickness, the amount of polishing of the surface will increase, and many coating layers will have to be undesirably discarded, making it less economical. have a problem

Therefore, the purpose of the present invention is to solve the above-mentioned technical problems, to ensure a predetermined thickness with the thinnest coating layer possible, and to improve productivity and economic efficiency. Our goal is to provide sewing machine parts.

Means for Solving the Problems In the present invention, a main body 7 is formed by injection molding a synthetic resin mixed with glass powder, a first coating layer 9a made of ceramic is formed on the surface 20 of this main body 7, and the first coating layer 9a is formed by cutting. After that, the surface 24 of this first coating layer 9a
This is a sewing machine part characterized in that a second coating layer 9b made of ceramic is provided on the surface of the sewing machine to form a smooth surface 26.

Further, the present invention is characterized in that the component has an inner pot.

Further, the present invention is characterized in that the part has an outer hook.

Further, the present invention is characterized in that the component is a bobbin.

Further, the present invention is characterized in that the component is a bobbin case.

Further, the present invention is characterized in that the component is a balance.

Further, the present invention is characterized in that the component is a looper of a chain stitch sewing machine.

Effects According to the present invention, since the parts of the sewing machine are made of a material that is a mixture of synthetic resin and glass powder, the main body can be manufactured by injection molding using a mold, which greatly improves productivity. can do. Moreover, since the main body is mixed with glass powder, it is stronger than a synthetic resin only, and is also lighter than a metal part. It is possible to reduce the weight of the entire sewing machine equipped with this.

Moreover, since a coating layer is formed on the surface of the synthetic resin main body and the parts are made of multiple types of materials, abnormal phenomena such as resonance can be prevented and noise can be reduced.

Furthermore, since the coating layer is made of ceramic,
It has excellent heat resistance and abrasion resistance, and can prevent seizures in parts that slide against each other. Moreover, the ceramic coating layer has a small coefficient of friction, so the thread slides smoothly on areas where the thread slides, such as the outer surface of the inner hook, and the tension when the thread slides does not change unnecessarily. It is possible to prevent this from happening. In this way, by preventing seizure and reducing the amount of wear, it is possible to extend the life of parts.
Durability is improved.

According to the present invention, the coating layer is formed by forming a first coating layer on the surface of the main body and cutting it, and then forming a second coating layer made of ceramic on the surface of the first coating layer. As a result, the second coating layer on the first coating layer, which has already been cut almost flat, has almost no large irregularities, so the amount of polishing is small, and the wastage of material is minimized. , a predetermined thickness can be reliably obtained with thin first and second coating layers.

Embodiment FIG. 1 is a perspective view of an inner hook as a part of a sewing machine according to an embodiment of the present invention, and FIG. 2 is a sectional view of a part thereof. The inner hook 1 is formed with a rail 2 that fits into the outer hook and into a track groove formed on the inner peripheral surface of the outer hook. Main body 3 of this inner pot 1
is made of synthetic resin reinforced by mixing glass powder, and a ceramic coating layer 4 is formed on its surface.

This ceramic is generally made of aluminum oxide (Al ₂ O _{3 ) or press-formed and sintered aluminum oxide (Al 2 O 3} ) or a small amount of other metal oxides or binders added to it, and its hardness increases up to about 1100°C. does not change. Its specific heat is about four times that of cemented carbide, its thermal conductivity is about half that of cemented carbide, and it has little thermal expansion. Moreover, while cemented carbide undergoes considerable oxidation and deterioration at temperatures above about 1000°C, ceramics are stable up to about 2000°C and have a low affinity for most metals, making it difficult to weld with other objects and prevent wear. It has the characteristic of being strong.

The inner pot body 3 on which the tough ceramic coating layer 4 is formed is manufactured by injection molding.
During this injection molding, the rail 2 made of a highly hard material such as iron is integrally molded.

Since the main body 3 is manufactured by injection molding,
Therefore, the inner pot 1 having a complicated shape can be easily manufactured, and is extremely easy to manufacture compared to the prior art pots made of materials such as iron. In order to further improve accuracy, the coating layer 4 may be cut. The coating layer 4 can be composed of a plurality of layers, the lower layer is subjected to cutting, etc., and then the upper layer is formed to make the outer circumferential surface of the coating layer 4 smooth, that is, a surface without unevenness. can.

More specifically, as shown in FIG. 2A, the first coating layer 9a is formed with a predetermined thickness T1 on the surface 20 of the main body 3, and the surface 21 is covered with the second coating layer 9a.
As shown in FIG. 2, the deepest recess 23 of the surface 21 is cut to the surface 24 so that it has an average thickness T2 smaller than the thickness T1.
, thereby making the surface 2
4 is made substantially flat, and then, as shown in FIG. 2A and 3, a second covering layer 9b is formed on the surface 24 of the first covering layer 9a. At this time, the surface 25 of the second coating layer 9b is flat and approximately parallel to the surface 24 of the first coating layer 9a, and is slightly polished to a position 26 shown by an imaginary line so as not to create a recess. As a result, a smooth surface 26 can be obtained.
In this way, the thinnest possible covering layers 9a, 9b can be formed and slightly polished to obtain a predetermined effective thickness T3, and their surfaces can be finished extremely smoothly.

FIG. 3 is a perspective view of the outer hook 6 in which the inner hook 1 is housed, and FIG. 4 is an enlarged sectional view of a portion of the inner hook 6. The main body 7 of the outer hook 6 is made of synthetic resin mixed with glass powder, and has a track groove 8 into which the rail 2 of the inner hook 1 is fitted. A coating layer 9 similar to the coating layer 4 described above is formed on the outer surface of the main body 7.

FIG. 5 is a perspective view of a bobbin 10 according to another embodiment of the present invention, and FIG. 6 is a perspective view showing a bobbin case 11 according to still another embodiment of the present invention. Such bobbin 10 and bobbin case 11 also have
The structure is similar to that of the inner hook 1 and outer hook 6 described above.

FIG. 7 is a perspective view of a balance 12 according to another embodiment of the present invention, and FIG. 8 is a perspective view of a looper 13 of a sewing machine. The balance 12 and the looper 13 are also
It has the same configuration as the inner hook 1 and outer hook 6 described above.

The present invention can be implemented not only in connection with a vertical or horizontal full-rotation hook of a lockstitch sewing machine, but also in connection with a half-rotation hook of a lockstitch sewing machine.
It can be implemented. Moreover, as mentioned above, it can also be implemented in connection with the looper 13 of a chain stitch sewing machine.

Effects of the invention As described above, according to the invention, the main body is formed by injection molding of synthetic resin mixed with glass powder, which improves productivity and allows manufacturing at low cost and with high precision. . Furthermore, since a ceramic coating layer is formed on the surface of the main body, the surface can be made highly hard and heat resistance and abrasion resistance can be improved.

Moreover, since the main body is made of synthetic resin, it can be made lighter than when using metal, and when parts such as an outer hook that rotate at high speed are stopped, undesirable effects due to inertia can be avoided. In particular, it is possible to prevent the bobbin, which is a part, from spinning idly, thereby eliminating undesired unwinding of the bobbin thread and preventing the thread from becoming sagging.

In particular, according to the present invention, after forming the first coating layer on the surface of the main body and cutting it, the second coating layer is formed on the surface of the first coating layer to make the surface smooth. The surface of the second coating layer on the first coating layer, which has been made substantially flat by cutting the surface of the first coating layer, is a flat surface that is substantially parallel to the surface of the first coating layer after cutting. This makes it possible to reduce the amount of polishing as much as possible, eliminate waste of material, and ensure a predetermined thickness accurately and reliably.

[Brief explanation of drawings]

Fig. 1 is a perspective view of an inner pot 1 according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of a part of the inner pot 1, and Fig. 2A shows a plurality of coating layers 9a and 9b formed on the surface of the main body 3. FIG. 3 is a perspective view of the outer hook 6 in which the inner hook 1 is stored;
4 is a cross-sectional view of a part of the outer hook 6, FIG. 5 is a perspective view of a bobbin 10 according to another embodiment of the present invention, and FIG. 6 is a perspective view of a bobbin case 11 according to still another embodiment of the present invention. Figure 7 shows a balance 1 of another embodiment of the present invention.
FIG. 8 is a perspective view of a looper 13 according to another embodiment of the present invention. 1...Inner hook, 2...Rail, 3...Inner hook body, 4, 9...Coating layer, 6...Outer hook, 7...Outer hook body, 8...Rail groove, 10...Bobbin, 11...
...Bobbin case, 12... Balance, 13... Looper, 9a... First coating layer, 9b... Second coating layer,
20...Surface of main body 3, 24...First coating layer 9a
surface, 26...the surface of the second coating layer 9b.

Claims (1)

[Claims for Utility Model Registration] (1) The main body 7 is formed by injection molding a synthetic resin mixed with glass powder, and the first coating layer 9a made of ceramic is formed on the surface 20 of the main body 7, and then cut. After that, a second coating layer 9b made of ceramic is provided on the surface 24 of the first coating layer 9a to form a smooth surface 26. (2) The part for a sewing machine according to claim 1, wherein the part has an inner hook. (3) The part for a sewing machine according to claim 1, wherein the part has an outer hook. (4) The part for a sewing machine according to claim 1, wherein the part is a bobbin. (5) The part for a sewing machine according to claim 1, wherein the part is a bobbin case. (6) The part for a sewing machine according to claim 1, wherein the part is a balance. (7) The part for a sewing machine according to claim 1, wherein the part is a looper for a chain stitch sewing machine.