JPS6146685B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an improved method for manufacturing plastic needle holders.

Conventionally, the needle holder A for needle bearings has been formed by integrally pressing a short steel tube as shown in Fig. 1, or by pressing a steel plate and having a needle holder B formed therein. However, it is formed by bending this into a cylindrical shape and welding its both ends.

However, in the case of the former cage formed integrally by press working the short tube, the needle holding part B
In addition to having relatively low dimensional accuracy, it also requires a finishing process to remove the burrs left on the outer periphery of holding part B during press processing, which reduces needle rolling performance and productivity.
Many problems remain in terms of processing accuracy.
In addition, even in the case of a cage with the latter welded finish, in addition to the welding process, the needle holding part B is
This requires a cleaning process to remove metal dust, etc. that has adhered to the surface, and as with the former, various problems remain.

On the other hand, in order to solve the above-mentioned problems with conventional steel needle holders, the needle holder was molded from a plastic material with excellent heat resistance and wear resistance, and By creating a structure that can store and support the needle during assembly, it is possible to simplify the assembly process of the needle bearing, improve the finishing accuracy of the needle holding part, prevent noise, reduce weight, and significantly reduce manufacturing costs. Plastic needle retainers have been developed (Japanese Unexamined Patent Publication No. 17853/1983, No. 22329/1983, etc.).

By the way, conventional plastic needle retainers are assembled by forming recesses and protrusions for fitting on two members constituting the retainer, and gluing or welding both contact surfaces of the recesses and protrusions. There is. However, since these conventional needle holders are constructed in such a way that the contact surfaces of the mated concave and protruding parts are directly adhered or welded, the adhesive and plastic material melted during welding inevitably come into contact with the joint surface of both parts. As a result, problems such as an increase in the number of defective products and a decrease in quality are unavoidable, and this problem becomes even more difficult as the cage becomes smaller.

The present invention aims to solve the above-mentioned problems in plastic needle cages, and it is possible to smoothly and reliably weld the joint surfaces of two members constituting the cage, and also to make it possible to weld the joint surfaces of two members constituting the cage smoothly and reliably. It is an object of the present invention to provide a method for manufacturing a plastic needle holder that eliminates the elution of .

The present invention provides vertical notches having an appropriate width at regular intervals on the peripheral wall of the cylindrical body, and connects the needle holding parts 3, 3 between the column bodies 1a, 1a formed by the notches.
..., and the needle holding parts 3, 3...
a plastic retainer body 1 having a needle contact surface 3a having a concave curved surface along the outer surface of the needle 4, and a protrusion 5 or a recess 6 formed in the upper end surface 1b of the columnar body 1a; A flanged side plate 2 made of plastic having a recess 6 or projection 5 that fits therein is formed at a position facing the projection 5 or recess 6 of the container body 1, and the needle is attached to the needle holding portion 3. 4 and the protrusion 5 is fitted into the recess 6 to assemble the plastic needle so that the joint between the upper end surface 1b of the column 1a and the inner surface 2a of the side plate 2 is fixed and integrated. In the cage manufacturing method, the columnar upper end surface 1b
around the protrusion 5 or recess 6 and the inner surface 2 of the side plate.
A needle-like protrusion 7 with a reduced diameter at the tip is placed in either the recess 6 or around the protrusion 5 of a, and a shallow depression having a shape that receives the needle-like protrusion 7 and reduces in diameter toward the bottom on the other side. When the protrusion 5 and the recess 6 are fitted together, the needle-like protrusion 7 is inserted into the shallow recess 8 and the outer circumferential surface of the tip thereof is brought into contact with the inner circumferential surface of the deep part of the shallow recess 8. The basic structure of the invention is to bring them into contact and to melt and fix the needle-like protrusion 7 and the shallow recess 8 by ultrasonic welding.

Hereinafter, details will be explained based on the embodiments of the present invention shown in FIGS. 2 to 13. The needle holder is composed of a holder main body 1 and a side plate 2 shaped like a brim.

The cage body 1 is formed by integral molding of so-called engineered plastic, such as hard nylon or polyacetate, which has excellent heat resistance, corrosion resistance, and wear resistance. As shown in FIG. 8, each support column 1a, 1 is formed by vertically cutting out the outer circumferential wall of a cylindrical body with a constant width and interval.
A plurality of needle holding parts 3 are formed between each part a.

The outer peripheral surface of the needle holding portion 3, that is, the needle 4
As shown in FIGS. 2 and 7, the contact surface 3a is finished with a concave curved surface along the outer peripheral surface of the needle 4 to be held, and the needle 4 inserted from above is vertically inserted into the holding part 3. It will be stored and supported in the direction. Reference numeral 5 denotes a cylindrical (or conical) protrusion formed on the upper end surface 1b of each support column 1a of the cage main body 1, into which a recessed part of a brim-shaped side plate 2, which will be described later, fits. will be done.

FIGS. 4 and 5, and FIGS. 9 and 10 are a plan view and a cross-sectional view of the flanged side plate 2, which is made of molded engineering plastic in the same way as the cage body 1. It is formed into a ring shape with approximately the same inner and outer diameters. Reference numeral 6 denotes a circular (or inverted conical) recess formed on the inner surface of the side plate 2, and is provided at a position facing the protrusion 5 formed on the upper end surface 1b of the column of the main body 1. As shown in FIG. 6, by fitting the protrusion 5 of the main body 1 into the recess 6 of the side plate 2, the two can be assembled with a predetermined positional relationship regulated.

In the above embodiment, the protrusion 5 is formed on the upper end surface 1b of the support column of the cage body 1, and the recess 6 is formed on the inner surface 2a of the side plate 2, but the formation of the protrusion 5 and the recess 6 is Of course, the positions may be reversed.

Projections 5 on the upper end surface 1b of each column of the cage main body 1
As shown in the partially enlarged view of FIG. 11, a plurality of (3 to 12) needle-like protrusions 7 are formed around the . As shown in the enlarged sectional view of FIG. 13, the needle-like protrusion 7 is formed into a pointed shape by reducing the diameter of the tip.

On the other hand, around the recess 6 in the inner surface 2a of the side plate 2, a shallow recess 8 for receiving the needle-shaped protrusion 7 is bored, as shown in the partially enlarged view of FIG. As shown in the enlarged cross-sectional view of FIG. 13, the shallow recessed portion 8 is formed into a shape whose diameter gradually decreases toward the bottom, that is, an inverted conical shape, and when the cage main body 1 and the brim-shaped side plate 2 are combined, , the protrusion 5 formed on the upper end surface 1b of the support column of the cage main body 1 and the inner surface 2a of the brim-shaped side plate 2.
The formation positions of both 7 and 8 are determined so that when the needle-like protrusion 7 is fitted into the recess 6 formed in the recess 6, the needle-like protrusion 7 just enters into the shallow recess 8.

In this embodiment, the needle-like protrusion 7 is formed on the upper end surface 1b of the column of the cage body 1, and the shallow recess 8 is formed on the inner surface 2a of the side plate 2. It goes without saying that the shallow recess 8 may be provided on the upper end surface 1b and the needle-like projections 7 may be provided on the inner side surface 2a of the side plate.

Next, a method of assembling the plastic needle holder according to the present invention will be explained.

First, the needles 4 are vertically inserted into each needle holding part 3 of the holder body 1 from above. Next, the side plate 2 is disposed above the support column 1a, and the protrusion 5 is fitted into the recess 6 to assemble the main body 1 and the side plate 2.

In this case, by fitting the protrusions 5 into each recess 6, the mutual assembly position of the retainer body 1 and the side plate 2 is regulated extremely accurately, and the needle retainer and each needle 4, 4 will be automatically aligned. Furthermore, by fitting the protrusion 5 into the recess 6, each needle-like protrusion 7 formed around the protrusion 5 also fits into each shallow recess 8 formed around the recess 6. The tip of the protrusion 7 comes into contact with the bottom of the shallow recess 8. In addition, in this state, the upper end surface 1b of the column and the inner surface 2 of the side plate
A small gap is maintained between a and a to perform ultrasonic welding.

Once the assembly of the cage body 1 and side plate 2 is completed,
The joint portion between the upper end surface 1b of each column and the inner side surface 2a of the side plate is fixed by ultrasonic welding. That is, by using ultrasonic energy, the outer circumferential surface of the tip of the needle-like protrusion 7 on the upper end surface 1b of each column is brought into contact motion with the inner circumferential surface of the deep part of the shallow recess 8 on the inner surface 2a of the side plate, and the thermal energy is released. By melting the resin at the contact portion, the cage main body 1 and the side plate 2 are tightly fixed as shown in FIG. 13.

In the present invention, by providing the needle-like protrusion 7 and the shallow recess 8, the cage main body 1 and the side plate 2
The surplus resin C that melted when ultrasonically welding the
This allows the welding of the joint surfaces to be performed more smoothly and reliably during ultrasonic welding, and it is possible to obtain a clean welded surface without melting of the molten resin.

Further, in the present invention, since the energy density applied to the welded portion during ultrasonic welding is increased, welding strength is improved and an extremely smooth bonded surface can be obtained.

Further, in each of the above embodiments, the needle holding part 3 is formed into a straight shape to hold the cylindrical needle 4, but the needle holding part 3 and its needle contact surface 3a are formed into a tapered shape. By forming it, it is also possible to use a truncated conical needle 4.

As described above, in the present invention, a protrusion 5 is formed on one of the main body 1 and the side plate 2, and a recess 6 is formed on the other, and the two are assembled by fitting the recess 6 and the protrusion 5. That's what I do. As a result, positioning when assembling the main body 1 and the side plate 2 becomes easier, the needle holder and the needle 4 can be automatically aligned when assembling the holder, and furthermore, the assembly of the main body 1 and the side plate 2 Strength is also significantly improved.

Further, a plurality of needle-like protrusions 7 are placed on either the joint surface 1b of the main body 1 and the joint surface 2a on the side plate 2 side, and a shallow recess 8 that receives the needle-like projections 7 on the other side.
is formed, the protrusion 7 is inserted into the shallow recess 8, the outer circumferential surface of the tip thereof is brought into contact with the inner circumferential surface of the deep part of the shallow recess 8, and the two are melted and fixed by ultrasonic welding. During ultrasonic welding, the molten resin does not leak out from the joint surface, reducing the number of defective products and greatly improving the quality of the cage.In addition, the energy density of the welded part during ultrasonic welding improves, which improves both The melting and fixing strength of the two is significantly increased, and there is no possibility that the two will come apart during use.

As mentioned above, the present invention has excellent practical effects.

[Brief explanation of the drawing]

FIG. 1 is a perspective view showing an example of a conventional steel needle holder. FIG. 2 is a plan view of the holder main body constituting the needle holder of the present invention, FIG. 3 is a front view thereof, and FIG. 4 is a plan view of the brim-shaped side plate.
FIG. 5 is a cross-sectional view taken along the line AA in FIG. 4, and FIG. 6 is a partial cross-sectional view showing a fixed portion between the cage main body 1 and the side plate 2. Fig. 7 is a plan view of another cage main body, Fig. 8 is a front view thereof, Fig. 9 is a plan view of the brim-shaped side plate, and Fig. 10 is a sectional view taken along line AA in Fig. 9. It is. FIG. 11 is a partially enlarged perspective view showing the upper end of the column on the cage body, and FIG. 12 is a partially enlarged cross-sectional view of the side plate 2. FIG. FIG. 13 is a partially enlarged sectional view of the joint. DESCRIPTION OF SYMBOLS 1... Cage main body, 1a... Column body, 1b... Upper end surface of pillar, 2... Flange-shaped side plate, 2a... Inner surface of side plate, 3...
Needle holding portion, 3a...Needle contact surface, 4...Needle, 5...Protrusion, 6...Recess, 7...Needle retainer, 8...Shallow recess.

Claims (1)

[Claims] 1 Vertical notches having an appropriate width are provided at regular intervals on the peripheral wall of the cylindrical body, and the space between the pillars 1a and 1b formed by the notches is used as needle holding parts 3, 3..., and the needle holding part 3... has a needle contact surface 3a that is a concave curved surface along the outer surface of the needle 4, and a plastic retainer body 1 that has a protrusion 5 or a recess 6 formed on the upper end surface 1b of the column 1a. ; A flanged side plate 2 made of plastic having a recess 6 or a projection 5 that fits therein is formed at a position facing the projection 5 or recess 6 of the retainer main body 1; 3, and the protrusion 5 is fitted into the recess 6, so that the joint between the upper end surface 1b of the column 1a and the inner surface 2a of the side plate 2 is fixed and integrated. In the method for manufacturing a plastic needle holder, the tip is compressed either around the protrusion 5 or the recess 6 on the upper end surface 1b of the columnar body, or around the recess 6 or the protrusion 5 on the inner side surface 2a of the side plate. A needle-like protrusion 7 with a large diameter is formed on the other side, and a shallow recess 8 that receives the needle-like protrusion 7 and has a diameter reduced toward the bottom is formed on the other side, and the protrusion 5 and the recess 6 are fitted together. At this time, the needle-like protrusion 7 is inserted into the shallow recess 8, the outer circumferential surface of its tip is brought into contact with the inner circumferential surface of the deep part of the shallow recess 8, and the needle-like protrusion 7 and the shallow recess 8 are bonded together by ultrasonic welding. A method for manufacturing a plastic needle retainer, characterized by melting and fixing the same.