JP5397101B2 - Method for manufacturing horizontal wheel for suspension vehicle - Google Patents

Description

  The present invention relates to a method for manufacturing a horizontal wheel used in a suspension vehicle that travels along a ceiling rail and suspends a movable panel.

As a suspension car that runs along the ceiling rail and suspends movable panels such as movable partitions and sliding folding doors, the horizontal wheel is supported by a suspension shaft, and the lower surface of the horizontal wheel is separated from the side piece of the rail. There is one that is brought into contact with the upper surface of the traveling piece that extends inward (see, for example, Patent Documents 1 to 3).
Horizontal wheels used for suspension vehicles having such a structure are commercially available for suppressing wear of aluminum alloy ceiling rails, reducing noise when the horizontal wheels travel on the ceiling rails, and reducing the cost of the horizontal wheels. Generally, the outer ring of a mass-produced bearing is covered with a resin ring (see, for example, page 3 and FIG. 1 of Patent Document 1). It is manufactured by insert molding so as to be embedded (see, for example, page 5 of Patent Document 1).

Japanese Utility Model Publication No. 4-59287 (FIGS. 1 and 4) JP 2007-262858 A (FIG. 2) Japanese Patent Laying-Open No. 2009-133060 (FIG. 2)

  In a horizontal wheel manufactured by press-fitting a bearing into a resin ring, since the upper and lower surfaces of the outer ring cannot be covered with the resin ring, there is a problem in terms of reliability that the resin ring may come off the bearing.

In addition, the horizontal wheel manufactured by insert molding so as to embed the bearing is such that the resin ring peels from the outer ring so that the outer ring is held by the force of the resin contraction so that the outer peripheral surface and both side surfaces of the outer ring are covered with the resin. It is molded so as not to drop off (see, for example, FIG. 1 (b) of Patent Document 1).
However, since the resin covers only a part of both side surfaces of the outer ring and the resin is fixed to the outer ring only by shrinkage of the resin, the resin ring wears and creeps during use, and the resin ring is removed from the outer ring. There is a problem that peeling or dropping is likely to occur.
In addition, horizontal wheels are used with the lower surface of the resin wheel in contact with the upper surface of the running piece that extends inward from the side piece of the rail, so a load is applied to the lower surface of the resin wheel. In some cases, the resin on the lower side of the outer ring does not satisfy the required strength and wear resistance.

Here, in order to improve load bearing performance, insert molding is performed so that the resin amount is increased to cover a part of the metal shield plate of the shield type bearing that is a commercial mass-produced product. The resin flows into the bearing through a slight gap (shield plate notch), or the shield plate with relatively low rigidity collapses due to molding pressure (injection pressure and holding pressure) and contacts the cage inside the bearing. In the past, such insert molding is not employed because of the problem of rotation failure or inability to rotate, and insert molding is performed so that only a part of both side surfaces of the outer ring are covered with resin rings (for example, (See FIG. 1 (b) of Patent Document 1).
In addition, it is conceivable to manufacture and install a highly rigid shield plate instead of the metal shield plate of the above-mentioned bearing for mass-produced products, but manufacturing such a special shield plate significantly increases the cost. To do.

Therefore, in view of the above-mentioned situation, the present invention intends to solve the problem that a horizontal wheel for a suspended vehicle is manufactured at low cost by insert molding so as to embed a shield-type bearing not provided with a special shield plate having high rigidity. Although it is a method, it exists in the point which provides the manufacturing method of the horizontal wheel for suspension vehicles which can improve intensity | strength and abrasion resistance.

In order to solve the above problems, the method for manufacturing a horizontal wheel for a suspended vehicle according to the present invention is a horizontal wheel for a suspended vehicle that runs along a ceiling rail and suspends a movable panel, and has a special shield with high rigidity. A shield-type bearing not provided with a plate is used as an insert product, and the lower surface of the resin ring contacts the upper surface of the traveling piece of the ceiling rail, which is formed by insert molding on the outer peripheral surface and both side surfaces of the outer ring. An injection method for manufacturing a horizontal wheel, wherein an injection mold in which a cavity is formed so that a resin covers a part of a lower shield plate of the bearing is used, and a molten resin is injected into the cavity. In the case where the molten resin is injected and injected from the gate formed so as to be positioned on the outer peripheral surface side of the resin wheel or on the outer peripheral side end of the side surface, the molten resin does not hit the lower shield plate Is filled at a high speed, and from the position where the molten resin is applied to the lower shield plate, it is charged at a low speed so as to suppress the deformation of the lower shield plate. In the pressure-holding process for accurately transferring the shape and dimensions of the cavity, the injection molding machine is controlled so that the pressure at the first stage is lowered and held for a certain period of time in order to form a required solidified layer.

According to such a method for manufacturing a horizontal wheel for a suspended vehicle, in the injection process, the molten resin is filled at a high speed up to a position where the molten resin does not cover the lower shield plate, and the lower shield is protected from the position where the molten resin is applied to the lower shield plate. Since filling is performed at a low speed so as to suppress deformation of the plate, the injection pressure is lowered from the position where the molten resin is applied to the lower shield plate, so that deformation of the lower shield plate can be suppressed and the outer ring of the bearing The resin can be prevented from entering the bearing through a slight gap (notch in the shield plate) between the lower shield plate and the inside of the bearing.
Further, in the pressure keeping process following the injection process, the first stage pressure is lowered and held for a certain time in order to form a required solidified layer, so that the solidified layer reinforces the lower shield plate. Since the holding pressure in the second and subsequent stages is gradually increased as necessary or the holding time is set longer, voids (cavities generated in the molded product) and sink marks (dents generated on the molded product surface), etc. It is possible to mold a resin wheel with good transferability.

Therefore, in the horizontal wheel manufactured by such a manufacturing method, since the inflow of the resin into the bearing and the depression deformation of the shield plate are eliminated, the problem that the horizontal wheel (bearing) becomes defective or unable to rotate is eliminated. Can do.
In addition, the resin volume is increased so that the resin ring covers a part of the metal shield plate of the shield type bearing that does not have a special shield plate with high rigidity. Therefore, the strength and wear resistance of the resin wheel can be improved, and the effect of suppressing the peeling or dropping of the resin wheel from the outer ring can be enhanced.

Here, it is preferable that a convex strip is formed on the injection mold so that a groove having at least one of spiral, radial and concentric grooves is transferred to the lower surface of the resin ring.
According to such a method for manufacturing a horizontal wheel for a suspension vehicle, in addition to the above-described effects, in the horizontal wheel manufactured by such a manufacturing method, abrasion powder of resin wheels, dust adhered to the upper surface of the traveling piece of the ceiling rail, etc. Since it becomes difficult to remain on the rolling / sliding surface by entering the groove, it is possible to suppress the occurrence of secondary wear that wears the resin part, further improving wear resistance, Reliability can be improved over a wide range.

As described above, according to the method for manufacturing a horizontal wheel for a suspended vehicle according to the present invention, the horizontal wheel for a suspended vehicle can be manufactured at low cost by insert molding so as to embed a shield-type bearing not provided with a special shield plate having high rigidity. Although it is a method of manufacturing with, it is possible to improve the strength and wear resistance of the resin wheel and to suppress peeling or dropping of the resin wheel from the outer ring, and to improve reliability over a long period of time. Has a remarkable effect.

It is a fragmentary longitudinal cross-section which shows the state which engaged the suspension vehicle using the horizontal wheel manufactured with the manufacturing method which concerns on embodiment of this invention with the ceiling rail. It is composition explanatory drawing of the horizontal wheel manufactured by the manufacturing method concerning an embodiment of the invention, (a) is a fragmentary longitudinal section, and (b) is a bottom view. It is a principal part expanded vertical sectional view which shows the metal mold | die for injection molding. It is a bottom view which shows the groove | channel formed in the lower surface of a resin ring, (a) is spiral, (b) is radial, (c) has shown the concentric groove | channel.

  Next, embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to the embodiments shown in the accompanying drawings, and includes all the embodiments that satisfy the requirements described in the claims. It is a waste.

  As shown in FIG. 1, the suspension wheel 11 is configured by pivotally supporting upper and lower horizontal wheels 1, 1 separated by a spacer 13 by a suspension shaft 12, and the lower surface of the horizontal wheels 1, 1 is on the ceiling rail R side. Since the upper and lower traveling pieces S, S extending inward from the pieces are in contact with each other, the horizontal wheels 1, 1 can move along the ceiling rail R and are suspended using the threaded portion 12 </ b> A of the suspension shaft 12. A movable panel (not shown) such as a movable partition or a sliding folding door provided can be moved along the ceiling rail R.

As shown in FIG. 2, the horizontal wheel 1 is composed of a double-shielded deep groove ball bearing 2 and a resin ring 7 that are commercially available mass-produced products, and an outer peripheral side portion of the outer ring 4 of the double-shielded deep groove ball bearing 2 that is an insert product. Is an insert-molded product that is solidified in a state where the resin ring 7 that is a resin-molded product is wrapped.
Both shield type deep groove ball bearings 2 are such that an inner ring 3 and an outer ring 4 rotate relatively via rolling elements 5 held by a retainer (not shown). Grease (not shown) is sealed as a lubricant, and the steel plate is sealed so that the grease is sealed in the annular space between the inner and outer rings 3 and 4 and the annular opening between the inner and outer rings 3 and 4 is blocked to prevent intrusion of foreign matter. Shield plates 6 and 6 that are press-formed metal rings are attached to the outer ring 4.
Further, the resin ring 7 covers the outer peripheral surface 4C, the upper side surface 4U and the lower side surface 4L of the outer ring 4, and further covers a part of the lower shield plate 6 inside the inner diameter portion of the outer ring 4. The lower surface (bottom surface) 7L of the resin wheel 7 is in contact with the upper surface of the traveling piece S in FIG.

Next, a method for manufacturing the horizontal wheel 1 will be described.
As shown in FIG. 3, the injection mold 8 comprises a fixed mold 8A and a movable mold 8B, and has a cavity C having the same shape as the resin wheel 7. A cavity C is formed so that the resin covers a part of the lower shield plate 6 (located on the upper side in FIG. 3) 6 of the ball bearing 2.
The double-shielded deep groove ball bearing 2 as an insert product is loaded into the fixed mold 8A and the movable mold 8B, and the fixed mold 8A and the movable mold 8B joined by the parting line (surface) PL. Then, a polyamide resin such as 66 nylon or a molten resin such as polyacetal resin is injected from the gate 10 into the cavity C through a sprue and runner 9 (not shown) from an injection device (not shown).
The gate 10 is formed on the outer peripheral surface side of the resin wheel 7 (see FIG. 2A), but may be formed on the outer peripheral side end of the side surface of the resin wheel 7.

Thus, in the injection process of injecting and injecting the molten resin into the cavity C, when the molten resin is injected and injected from the gate 10, the molten resin does not hit the lower shield plate 6 of the double shielded deep groove ball bearing 2 which is an insert product. From the position where the molten resin is applied to the lower shield plate 6 (the inner diameter side from the imaginary line A in FIG. 3) to the position (outer diameter side from the imaginary line A in FIG. 3) The injection molding machine is controlled to fill at a low speed so as to suppress the deformation of the lower shield plate 6.
The meaning of “suppressing the deformation of the lower shield plate 6” means that the horizontal wheel 1 after completion of molding due to resin leakage from the gap between the lower shield plate 6 and the outer ring 4 or the depression deformation of the lower shield plate 6. Since it is sufficient that the (both shield type deep groove ball bearings 2) have no rotation failure, slight deformation of the lower shield plate 6 is allowed.
By controlling the injection molding machine in such an injection process, since the injection pressure is lowered from the position where the molten resin is applied to the lower shield plate 6, the deformation of the lower shield plate 6 can be suppressed, and both shield types are used. The resin can be prevented from entering the inside of the bearing through the slight gap between the outer ring 4 of the deep groove ball bearing 2 and the lower shield plate 6 (notch in the shield plate 6).

Further, in the pressure-holding step for replenishing the shrinking resin and transferring the shape and size of the cavity C with high accuracy following the injection step, the first-stage pressure is lowered in order to form a required solidified layer. At the same time, the injection molding machine is controlled so as to hold for a certain time.
By controlling the injection molding machine in such a pressure-holding step, the solidified layer has an effect of reinforcing the lower shield plate 6, so that the pressure after the second stage is gradually increased or the pressure-holding time is increased as necessary. By setting the length long, it is possible to mold the resin ring 7 having good transferability without voids (cavities generated inside the molded product) and sink marks (dents generated on the surface of the molded product).

In the horizontal wheel 1 manufactured by the manufacturing method as described above, the flow of the resin into the double shielded deep groove ball bearing 2 and the depression deformation of the lower shield plate 6 are eliminated, so that the horizontal wheel 1 (bearing 2) rotates. It is possible to eliminate the problem of being defective or unable to rotate.
In addition, the resin amount is increased so that the resin ring 7 covers a part of the metal lower shield plate 6 of the double shielded deep groove ball bearing 2 that does not have a special high rigidity shield plate. Since the area of the resin coating portion of the portion (lower surface) is enlarged, the strength and wear resistance of the resin ring 7 can be improved, and the effect of suppressing the peeling or dropping of the resin ring 7 from the outer ring 4 is enhanced. be able to.

Further, as shown in FIG. 4, when the groove 7G is formed on the lower surface 7L of the resin wheel 7, wear powder of the resin wheel 7, dust adhering to the upper surface of the running piece S of the ceiling rail R or the like enters the groove 7G. This makes it difficult to remain on the rolling / sliding surface, so it is possible to suppress the occurrence of secondary wear that wears the resin part, further improving wear resistance and improving reliability over a long period of time. be able to.
The groove 7G has at least one shape of a spiral groove as shown in FIG. 4 (a), a radial groove as shown in FIG. 4 (b), and a concentric groove as shown in FIG. 4 (c). Any groove may be used, and it can be easily formed by forming a protrusion corresponding to the groove having the above-mentioned shape on the injection mold 8 (fixed side mold 8A).

(Example)
Using the injection mold 8 of FIG. 3, the double-shielded deep groove ball bearing 2 which is an insert product is 6302ZZ (inner diameter: 15 mm, outer diameter: 42 mm, width: 13 mm), injection speed two steps, pressure holding two steps Insert molding was performed under molding conditions of (first speed 40 mm / s, second speed 20 mm / s, primary holding pressure 10 Mpa / 5 s, secondary holding pressure 20 Mpa / 3 s).
As a result, the insert product is a commercially available mass-produced double shielded deep groove ball bearing 2 and the steel shield plate 6 has a thin thickness of about 0.2 mm, but there is no rotation failure and transferability. Further, the horizontal wheel 1 for a suspended vehicle having the shape shown in FIG. 2 could be manufactured.

In the above description, the case where the shield-type bearing not provided with the special shield plate having high rigidity is a deep groove ball bearing, but other bearings such as an angular ball bearing may be used.

DESCRIPTION OF SYMBOLS 1 Horizontal wheel 2 Double shield type deep groove ball bearing 3 Inner ring 4 Outer ring 4C Outer peripheral surface 4U Upper side surface 4L Lower side surface 5 Rolling element 6 Shield plate 7 Resin wheel 7L Lower surface 7G Groove 8 Injection mold 8A Fixed side die 8B Movable side Die 9 Runner 10 Gate 11 Suspension wheel 12 Suspension shaft 12A Screw part 13 Spacer C Cavity PL Parting line R Ceiling rail S Traveling piece

Claims (2)

This is a horizontal wheel for a suspension vehicle that runs along the ceiling rail and suspends the movable panel, and uses a shield-type bearing that does not have a special high-rigidity shield plate as an insert product. A method for producing a horizontal wheel, wherein the lower surface of the resin wheel is in contact with the upper surface of the traveling piece of the ceiling rail, which is formed by covering the surface with a resin wheel by insert molding,
Using an injection mold in which a cavity is formed so that a resin covers a part of the lower shield plate of the bearing,
In the injection step of injecting and injecting the molten resin into the cavity, when the molten resin is injected and injected from the gate formed so as to be positioned on the outer peripheral surface side or the outer peripheral end of the side surface, Filling at a high speed until the position does not cover the lower shield plate, filling from the position where the molten resin is applied to the lower shield plate at a low speed so as to suppress deformation of the lower shield plate,
In the pressure-holding step for replenishing the shrinking resin and transferring the shape and dimensions of the cavity with high accuracy following the injection step, the pressure at the first stage is lowered and a certain time is required to form a required solidified layer. A method of manufacturing a horizontal wheel for a suspended vehicle, wherein the injection molding machine is controlled so as to be held.
2. The suspension vehicle according to claim 1, wherein a protrusion is formed on the injection mold so that at least one of a spiral, radial, and concentric groove is transferred to a lower surface of the resin wheel. Manufacturing method of horizontal wheels.

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