JPH0653823U - Synthetic resin crown type cage - Google Patents

Abstract

(57) [Summary] [Purpose] Even if there is no space for abutting the eject pin between the holding portions 9 that are adjacent to each other with a small diameter, it can be manufactured by the axial draw. [PROBLEMS] Protrusions 16, 16 are provided at a plurality of outer peripheral edges of a main portion 8 so that the tips of eject pins can abut. At the time of injection molding, the tip of the eject pin is abutted against the protrusions 16 and 16, and the cage 7 immediately after molding is removed from the mold.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The synthetic resin crown type cage according to the present invention holds a plurality of balls constituting a ball bearing in a rolling state, and is used as a cage for a small diameter or a miniature bearing.

[0002]

[Prior art]

 Ball bearings as shown in FIG. 3 are widely used to support various rotating parts. In this ball bearing, an inner ring 2 having an inner ring raceway 1 on the outer peripheral surface and an outer ring 4 having an outer ring raceway 3 on the inner peripheral surface are concentrically arranged, and a plurality of inner ring raceways 1 and outer ring raceways 3 are provided between the inner ring raceway 1 and the outer ring raceway 3. It is configured by providing balls 5 and 5 that can be rolled. On the inner peripheral surfaces of both ends of the outer ring 4, the outer peripheral edges of the ring-shaped seal plates 6 and 6 are locked, respectively. It prevents leaks to the outside or dust that floats outside from entering this installation area.

Further, the plurality of balls 5 and 5 are rotatably held by a cage 7 as shown in FIGS. The cage 7 is called a crown type and is integrally formed by injection molding a synthetic resin. That is, the retainer 7 includes an annular main portion 8 and a plurality of sets of holding portions 9 and 9 provided on one surface of the main portion 8. Each holding part 9, 9 comprises a pair of elastic pieces 10, 10 arranged at a distance from each other. The surfaces of the pair of elastic pieces 10 and 10 forming the holding portions 9 and 9 which face each other are generally concentric spherical concave surfaces. However, some cages have a cylindrical surface on each surface. The balls 5 and 5 can be rolled into the holding portions 9 and 9 by pushing the gap between the elastic pieces 10 and 10 while elastically expanding the gap between the elastic pieces 10 and 10. Hold on.

FIGS. 6 to 8 show a state in which such a crown-shaped cage 7 is manufactured by so-called axial draw, in which injection molding is performed between molds which are divided into two in the axial direction of the cage 7. . The first die 11 and the second die 12 moved in the axial direction of the cage 7 (vertical direction in FIGS. 6 to 8) and moved closest to each other (the two dies 11 and 12 were butted against each other). In this state, a cavity 13 matching the outer shape of the cage 7 is formed between the molds 11 and 12. Eject pins 14 and 14 are inserted through the first die 11 having a shape matching the elastic pieces 10 and 10 in the axial direction of the cage 7. The tip of each eject pin 14, 14 is a part of the retainer 7 formed in the cavity 13 and faces the flat portions 15, 15 existing between the adjacent retaining portions 9, 9. .

When the retainer 7 is manufactured by using the above-described molds 11 and 12, first, as shown in FIG. 6, the first and second molds 11 and 12 are butted and the eject pins 14 and 14 are pulled in. In this state, the molten thermoplastic synthetic resin is poured into the cavity 13 and solidified.

After the synthetic resin is solidified in the cavity 13, the first and second molds 11, 12 are separated from each other as shown in FIG. 7, and then the eject pins 14, 14, as shown in FIG. Is pushed into the first mold 11. As a result, the tip portions of the eject pins 14 and 14 push the flat portions 15 and 15 of the retainer 7 that has just been formed to elastically deform the elastic pieces 10 and 10, while the retainer 7 is moved to the first position. Remove from mold 11.

[0007]

[Problems to be solved by the device]

 The synthetic resin crown type cage of the present invention is used for a small diameter or a miniature bearing, and a small (small diameter) cage can be manufactured by an axial draw, thereby reducing the manufacturing cost. Is.

In the case of a small-diameter cage such as a small-diameter or miniature bearing, which is incorporated in a small-sized ball bearing, as shown in FIGS. 1 and 2 showing an embodiment of the present invention, a space between adjacent holding portions 9 and 9 is small. Is narrow, the width of the flat portions 15, 15 between the holding portions 9, 9 becomes extremely narrow, or the flat portions 15, 15 themselves do not exist. On the other hand, the outer diameters of the eject pins 14, 14 for removing the retainer 7 from the first mold 11 cannot be made too small in terms of strength retention.

Therefore, conventionally, a small-sized synthetic resin crown type cage cannot be manufactured by an axial draw, and when such a cage is injection-molded, a plurality of dies are displaced in the diametrical direction. It was made by the so-called Radial Draw. However, compared to the axial draw, Radial draw has a more complicated die structure, and because the number of cages that can be made each time the mold is moved is small and production efficiency is poor, the cage manufacturing cost is low. Bulking was inevitable.

The crown holder made of synthetic resin of the present invention has been devised in view of the above circumstances.

[0011]

[Means for Solving the Problems]

 Like the conventional synthetic resin crown type cage described above, the synthetic resin crown type cage of the present invention is entirely manufactured by injection molding of synthetic resin, and has an annular main portion and this main portion. And a plurality of sets of holding portions provided on one surface. Then, each holding portion holds one ball rotatably, one by one, between a pair of elastic pieces that are arranged with a space therebetween.

In particular, in the synthetic resin crown type retainer of the present invention, the outer peripheral edge of the main portion is formed with a plurality of protruding portions at which the ends of the eject pins can be abutted at the time of injection molding. It is characterized by things.

[0013]

[Action]

 The function of the synthetic resin crown type cage of the present invention configured as described above to rotatably hold a plurality of balls is the same as that of the conventional synthetic resin crown type cage described above. It

In particular, in the case of the synthetic resin crown type retainer of the present invention, since the end of the eject pin can be freely abutted against the protrusion formed on the outer peripheral edge of the main portion, the retainer itself has a small diameter. Therefore, even if there is no space for abutting the eject pin between the adjacent holding parts, this holder can be made with an axial draw. Therefore, the production cost can be reduced.

[0015]

【Example】

 1 and 2 show an embodiment of the present invention. The synthetic resin crown type retainer of the present invention is characterized in that a plurality of outer peripheral edge portions of the main portion 8 are provided with protrusions 16 for abutting the tips of the eject pins 14, 14 (see FIGS. 6 to 8). , 16 are formed, and other configurations and operations are similar to those of the conventional structure described above. Therefore, the same parts are denoted by the same reference numerals, and the duplicate description will be omitted. I will explain it.

Protrusions 16 and 16 are formed on the outer peripheral edge of the main portion 8 at positions between the adjacent holding portions 9 and 9. Each of the projecting portions 16 and 16 projects from the outer peripheral edge in the shape of a semi-cylindrical bar, and the eject pins 14 and 14 can freely abut against the upper surfaces 17 and 17, respectively. The outer peripheral edges of the protrusions 16 and 16 are located inside the retainer 7 in the diametrical direction with respect to the ends of the balls 5 held by the holders 9 and 9 so that the protrusions 16 and the outer ring 4 (FIG. 3) to prevent interference with the inner peripheral surface.

In the case of the synthetic resin crown type retainer of the present invention configured as described above, the ends of the eject pins 14, 14 are projected to the protrusions 16, 16 formed at a plurality of outer peripheral edges of the main part 8. Since the retainer 7 itself has a small diameter and there is no space for abutting the tips of the eject pins 14, 14 between the adjacent holding portions 9, 9, since the retainer 7 itself can be applied freely, the first and second molds 11, 11, After the synthetic resin is injection-molded between 12 (FIGS. 6 to 8), the cage 7 can be separated from the first mold 11, and the cage 7 can be manufactured by an axial draw. Therefore, the production cost can be reduced.

Further, since the protrusions 16 and 16 themselves are small, and the weight increase of the cage 7 due to the provision of the protrusions 16 and 16 is slight, the weight of the ball bearing incorporating the cage 7 increases. Or, the response hardly decreases due to the increase of the inertial mass.

[0019]

[Effect of device]

 Since the synthetic resin crown type cage according to the present invention is constructed and operates as described above, the cost of manufacturing the cage and the ball bearings incorporating the cage can be reduced.

[Brief description of drawings]

FIG. 1 is a half enlarged plan view showing an embodiment of the present invention.

FIG. 2 is an enlarged perspective view corresponding to part A of FIG.

[Fig. 3] 1 of a ball bearing incorporating a synthetic resin crown type cage
The expanded sectional view which shows an example.

FIG. 4 is a half enlarged plan view showing a conventional cage.

FIG. 5 is an enlarged perspective view of the same.

FIG. 6 is a partially enlarged cross-sectional view showing a first step in the case of manufacturing a synthetic resin crown type cage by an axial draw.

FIG. 7 is a partially enlarged sectional view showing a second step of the same.

FIG. 8 is a partially enlarged sectional view showing a third step of the same.

[Explanation of symbols]

 1 Inner ring raceway 2 Inner ring 3 Outer ring raceway 4 Outer ring 5 Ball 6 Seal plate 7 Cage 8 Main part 9 Holding part 10 Elastic piece 11 First mold 12 Second mold 13 Cavity 14 Eject pin 15 Flat part 16 Projection 17 Top surface

Claims (1)

[Scope of utility model registration request] 1. An entire body made by injection molding of synthetic resin, comprising an annular main part and a plurality of sets of holding parts provided on one surface of the main part, and the holding parts are spaced from each other. In a synthetic resin crown type cage, which holds balls one by one between a pair of elastic pieces arranged as
A crown holder made of synthetic resin, characterized in that a plurality of protrusions are formed at a plurality of outer peripheral edges of the main portion, the protrusions being capable of abutting the ends of eject pins during injection molding.