JP2016141364A - caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a caster that can prevent a ball bearing from coming off from a main body frame even if the caster is applied with a large load when used in a transport vehicle or the like and has excellent durability.SOLUTION: The caster comprises a support shaft 1, a main body frame 3 made of synthetic resin having a ball bearing 2 for bearing the support shaft 1 subjected to insert molding, and a wheel 4 pivotally supported on the main body frame 3. At the center of a turning part 5 of the main body frame 3 is formed vertically penetratingly a shaft hole 7, into which is inserted the support shaft 1. Into an outer periphery of an outer wheel 2a of the ball bearing 2 is pressed a support wheel 8 with a width Wnarrower than a width Wof the outer wheel 2a. Upper and lower faces and an outer peripheral face of the outer wheel 2a and the whole of the support wheel 8 are subjected to insert molding so as to be buried in the main body frame 3, then held at an inner periphery part of the shaft hole 7, and further an inner wheel 2b of the ball bearing 2 is fastened to the support shaft 1.SELECTED DRAWING: Figure 4

Description

  The present invention relates to a caster used in a shopping cart used in a supermarket or the like, a transport machine used in a factory premises, etc., or a wheelchair, a stroller, or other transport vehicles.

  Conventionally, as this type of caster, for example, as shown in FIG. 8, a support shaft 21 that is supported by various mounted bodies such as the above-mentioned transport vehicle and a ball bearing 22 that supports the support shaft 21 are inserted. There is a molded main body frame 23 made of synthetic resin and a wheel 24 pivotally supported on the main body frame 23 (Patent Document 1).

  The caster main body frame 23 is formed in a substantially downward U-shape, and support pieces 26 of the wheels 24 are extended downward at both left and right ends of the swivel portion 25 arranged substantially horizontally. In the center of the turning portion 25, a shaft hole 27 into which the support shaft 21 is inserted is formed so as to penetrate in the vertical direction. In the ball bearing 22, the outer ring 22 a is held on the inner peripheral portion of the shaft hole 27 by insert molding, and the inner ring 22 b is fixed to the support shaft 21.

  However, in the conventional caster, although the outer ring 22a of the ball bearing 22 is held by the inner peripheral part of the shaft hole 27 of the turning part 25 of the main body frame 23 by insert molding, The thickness is approximately the same as the thickness of the inner ring 22b, and is thin as about 2 to 3 mm by actual measurement. Therefore, when the outer ring 22a is held by insert molding, a little width (in actual measurement) Only about 1 to 2 mm wide).

  For this reason, in the conventional caster, when the wheel 24 is turned and a load such as a carriage is applied to the support shaft 21, the outer ring 22 a of the ball bearing 22 may come off from the main body frame 23. It had the problem that.

  Therefore, in order to solve such problems of the conventional casters, the present applicant has applied for a caster as shown in FIG.

  The caster shown in FIG. 9 is a synthetic resin-made main body frame 33 in which a support shaft 31 and a ball bearing 32 that supports the support shaft 31 are insert-molded, and a wheel 34 that is supported by the main body frame 33. And the ball bearing 32 is formed by insert molding so that the outer ring 32a is thicker than the inner ring 32b, and the upper and lower surfaces and outer peripheral surface of the outer ring 32a are embedded in the main body frame 33, and the inner peripheral portion of the shaft hole 37 is formed. Further, the inner ring 32b is fixed to the support shaft 31 (Patent Document 2).

JP 2002-347408 A JP 2010-274774 A

  The caster previously filed by the applicant of the present application adopts the above-described configuration, so that even when a large load is applied to the caster when the ball bearing is insert-molded and held on the synthetic resin main body frame, The bearing is difficult to come off from the main body frame, and it has excellent durability.

  However, in the caster previously filed by the present applicant, the outer ring 32a of the ball bearing 32 is formed to be thicker than the inner ring 32b. Therefore, a general-purpose ball bearing cannot be used, and a dedicated ball bearing is used. If the outer ring 32a and the inner ring 32b are made of a synthetic resin, the amount of the synthetic resin used is increased and the cost is increased. If these are made of metal, the cost increases. As the amount of metal used increases, the cost increases, and the weight of the caster itself increases accordingly, making it difficult to use, resulting in new problems in terms of cost and usage. It was.

  Therefore, the present invention has an object to solve the above-mentioned conventional problems, and when used in a transport vehicle or the like, even when a large load is applied, the ball bearing is difficult to come off from the main body frame, Even if the outer ring and inner ring of the ball bearing are made of synthetic resin or metal, the caster is low in cost and easy to use without increasing the amount of use or the weight of the caster itself. It was made for the purpose.

For this reason, the caster of the present invention comprises a main body frame 3 made of synthetic resin in which a support shaft 1 and a ball bearing 2 that supports the support shaft 1 are insert-molded, and a wheel 4 that is supported by the main body frame 3. And a shaft hole 7 into which the support shaft 1 is inserted in the center of the swivel portion 5 of the main body frame 3 is formed so as to penetrate in the vertical direction, and the outer periphery of the outer ring 2a of the ball bearing 2 is A support ring 8 having a width W _s narrower than the width W _{o of the} outer ring 2 a is press-fitted, and insert molding is performed so that the upper and lower surfaces and the outer peripheral surface of the outer ring 2 a and the entire support ring 8 are embedded in the main body frame 3. The inner ring 2 b of the ball bearing 2 is fixed to the support shaft 1.

The caster of the invention, it is assumed that the pivot point S ₂ of the pivot point S ₁ and the wheel 4 of the support shaft 1 is shifted in the front-rear direction.

Further, in the caster of the present invention, the wheel 4 includes an axle 11 and a synthetic resin wheel 13 in which a ball bearing 12 for bearing the axle 11 is insert-molded, and the axle 11 is inserted in the center of the wheel 13. The shaft hole 15 is formed so as to penetrate in the left-right direction, and a support wheel 16 having a width W _s narrower than the width W _{o of the} outer ring 12 a is press-fitted into the outer periphery of the outer ring 12 a of the ball bearing 12. The left and right side surfaces and the outer peripheral surface of the wheel 13 and the entire support wheel 16 are insert-molded so as to be embedded in the wheel 13, held on the inner peripheral portion of the shaft hole 15 of the wheel 13, and further the inner ring 12 b of the ball bearing 12. Is fixed to the axle 11.

In the caster of the present invention, the width W _s of the support wheels 8 and 16 is set to be ½ or less of the width W _o of the outer ring 2a.

  Since the caster of the present invention is configured as described above, the caster was used in a shopping cart used in a supermarket or the like, a transport machine used in a factory premises, or a wheelchair, a stroller, or other transport vehicles. Sometimes, even when a large load is applied, the ball bearing is difficult to come off from the main body frame and has excellent durability, and the outer and inner rings of the ball bearing are made of synthetic resin or metal. The amount and weight of the caster itself are not increased, and it is easy to use at low cost.

It is a side view of the caster of this invention. It is a front view of the caster of this invention. It is a top view of the caster of this invention. It is a partial cross section side view of the caster of this invention. It is sectional drawing of the wheel of the caster of this invention. It is the half sectional view which expanded the state where the support ring was press-fit in the outer periphery of the outer ring of the ball bearing used for the turning part of the caster of this invention. It is the half sectional view to which the state which press-fitted the support ring to the outer periphery of the outer ring | wheel of the ball bearing used for the wheel of the caster of this invention was expanded. It is a partial cross section side view which shows an example of the conventional caster. It is a partial cross section side view which shows the other example of the conventional caster.

  Embodiments of casters according to the present invention will be described below in detail with reference to the drawings.

  As shown in FIGS. 1 to 5, the caster of the present invention is made of a synthetic resin in which a support shaft 1 that is supported by a mounted body such as a transport vehicle and a ball bearing 2 that supports the support shaft 1 are insert-molded. The main body frame 3 and wheels 4 pivotally supported on the main body frame 3 are provided.

And the caster of this invention makes it easy for the wheel 4 to turn, assuming that the shaft fulcrum S _{1 of the} support shaft 1 and the shaft fulcrum S ₂ of the wheel 4 are shifted in the front-rear direction (left-right direction in FIG. 1). I have to.

  As shown in FIG. 2, the main body frame 3 is formed in a substantially U-shape that faces downward, and the support pieces 6 of the wheels 4 are disposed at the left and right ends of the swiveling unit 5 that are arranged substantially horizontally. It is assumed that a shaft hole 7 into which the support shaft 1 is inserted is formed in the center of the revolving part 5 so as to penetrate in the vertical direction.

  As shown in FIGS. 4 and 5, the wheel 4 includes an axle 11 made of a bolt shaft, a synthetic resin wheel 13 in which a ball bearing 12 for bearing the axle 11 is insert-molded, and the wheel 13. The tire 14 is integrally fixed to the outer periphery of the tire. The wheel 13 is an annular body provided with an overhanging portion 13a on the outer periphery, and a shaft hole 15 into which the axle 11 is inserted is formed in the center thereof so as to penetrate in the left-right direction. The wheel 13 and the tire 14 may contain an antistatic agent so that static electricity is not generated during traveling on casters.

As shown in FIGS. 4 and 6, the ball bearing 2 has a large number of balls 2c interposed between a flat cylindrical outer ring 2a and a flat cylindrical inner ring 2b. the outer periphery of the outer ring 2a, it is assumed that was injected support wheel 8 having a width W _s is greater than the width W _o of the outer ring 2a. The upper and lower surfaces and the outer peripheral surface of the outer ring 2 a and the entire support wheel 8 are insert-molded so as to be embedded in the main body frame 3 and held on the inner peripheral portion of the shaft hole 7. Further, in the ball bearing 2, a support shaft 1 is inserted into an inner ring 2b, an intermediate portion of the support shaft 1 is fixed to an upper portion of the inner ring 2b with a nut 9, and a lower portion of the support shaft 1 is interposed with a washer 10 at a lower portion of the inner ring 2b. The inner ring 2b is fixed to the support shaft 1 by caulking.

The support wheel 8 is preferably made of metal, but can also be made of synthetic resin. As shown in FIG. 6, the width W _s is less than or equal to ½ of the width W _o of the outer ring 2a ( support wheel 8 shown has a width W _s to be are) set to about 1/6 of the width W _o of the outer ring 2a, and the thickness T _s substantially equal to the thickness T _o of the outer ring 2a Yes. If it does in this way, the said support wheel 8 will be light and a thing with a small volume. Since the support wheel 8 is subjected to a considerable amount of load of a mounted body such as a transport vehicle, it goes without saying that the width W _s and the thickness T _s are sufficient to withstand the load.

As shown in FIGS. 5 and 7, the ball bearing 12 also includes a large number of balls 12c interposed between a flat cylindrical outer ring 12a and a flat cylindrical inner ring 12b. the outer periphery of the outer ring 12a, it is assumed that was injected supporting wheel 16 having a width W _s is greater than the width W _o of the outer ring 12a. The left and right side surfaces and the outer peripheral surface of the outer ring 12 a and the entire support wheel 16 are insert-molded so as to be embedded in the wheel 13 and held on the inner peripheral portion of the shaft hole 15 of the wheel 13. Further, the ball bearing 12 has one end of an axle 11 such as a bolt inserted into the inner ring 12b from a through hole (not shown) provided in one support piece 6 of the main body frame 3, and the other end of the axle 11 is The inner ring 12b is fixed to the axle 11 by protruding from a through hole (not shown) provided in the other support piece 6 of the main body frame 3 and fastening with a nut.

The support wheel 16 is preferably made of metal, but can also be made of synthetic resin. As shown in FIG. 7, the width W _s is less than or equal to ½ of the width W _o of the outer ring 12a ( support wheels 16 shown has a width W _s to be are) set to about 1/6 of the width W _o of the outer ring 2a, and the thickness T _s substantially equal to the thickness T _o of the outer ring 12a Yes. If it does in this way, the said support wheel 16 will be light and a bulk will become narrow. In addition, since this support wheel 16 is similarly subjected to a considerable amount of load of a mounted body such as a transport vehicle, it goes without saying that the width W _s and the thickness T _s are sufficient to withstand the load.

As shown in FIG. 4, the caster of the present invention configured as described above is such that the pivot point S ₁ of the support shaft 1 and the pivot point S _{2 of the} wheel 4 are front and rear so that the wheel 4 can easily turn. Since it is shifted in the direction, when a load of a mounted body such as a transport vehicle is applied to the support shaft 1, the front lower portion (point A shown in FIG. 4) of the inner peripheral portion of the shaft hole 7 and the shaft hole 7 A large load is applied to the upper rear portion (point B shown in FIG. 4) of the inner peripheral portion of the. However, since the support wheel 8 is press-fitted into the outer periphery of the outer ring 2 a of the ball bearing 2, a considerable amount of the load is applied to the support wheel 8, and the front lower part of the inner peripheral part of the shaft hole 7, The load applied to the rear upper part of the inner peripheral portion of the shaft hole 7 is reduced.

Therefore, in the caster of the present invention, the outer ring 2a of the ball bearing 2 does not come off from the inner peripheral portion of the shaft hole 7 of the main body frame 3. Since the shaft fulcrum S _{1 of the} support shaft ₁ and the shaft fulcrum S _{2 of the} wheel 4 are shifted in the front-rear direction, the load on the mounted body such as a transport vehicle is applied to the support wheel 8 in the vertical direction. Rather, it is applied in an oblique direction. Therefore, even if the support wheel 8 is not fixed to the outer periphery of the outer ring 2a of the ball bearing 2 by welding or the like, it is assumed that the support wheel 8 is pressed from the outer periphery of the outer ring 2a of the ball bearing 2. It will never come out.

Further, in the caster of the present invention, when a load of a mounted body such as a transport vehicle is applied to the support shaft 1, the load is naturally applied to the axle 11 of the wheel 4 in the vertical direction. Are also distributed in the horizontal direction, and the load is applied to the axle 11 of the wheel 4 in an oblique direction. Then, the upper left portion of the inner peripheral portion of the shaft hole 15 and (C ₁ point shown in FIG. 5), the lower right portion of the inner peripheral portion of the axial hole 15 (D ₂ points shown in FIG. 5), or the shaft hole A large load is applied to the upper right portion (point D ₁ shown in FIG. 5) of the inner peripheral portion of 15 and the lower left portion (point C ₂ shown in FIG. 5) of the inner peripheral portion of the shaft hole 15. However, since the support ring 16 is press-fitted into the outer periphery of the outer ring 12 a of the ball bearing 12, a considerable amount of the load is applied to the support ring 16, and the upper left part of the inner peripheral part of the shaft hole 15 and The load applied to the lower right part of the inner peripheral part of the shaft hole 15 or the upper right part of the inner peripheral part of the shaft hole 15 and the lower left part of the inner peripheral part of the shaft hole 15 is reduced.

  Therefore, in the caster of the present invention, the outer ring 12a of the ball bearing 12 does not come off from the inner peripheral portion of the shaft hole 15 of the wheel 4. As described above, the load of the attachment body such as the transport vehicle is applied to the axle 11 of the wheel 4 in an oblique direction. Therefore, even if the support wheel 16 is not fixed to the outer periphery of the outer ring 12a of the ball bearing 12 by welding or the like, it is assumed that the support wheel 16 is press-fitted, and the support wheel 16 is removed from the outer periphery of the outer ring 12a of the ball bearing 12. It will never come out.

  Since the caster of the present invention is configured as described above, the caster was used in a shopping cart used in a supermarket or the like, a transport machine used in a factory premises, or a wheelchair, a stroller, or other transport vehicles. Sometimes, even when a large load is applied, the ball bearings 2 and 12 are difficult to be detached from the main body frame 3 and the wheels 4 and have excellent durability, and the outer rings 2a and 12a and the inner rings of the ball bearings 2 and 12 are excellent. Even when 2b and 12b are made of synthetic resin or metal, the amount of use and the weight of the caster itself are not increased, and the cost is low and easy to use.

DESCRIPTION OF SYMBOLS 1 Support shaft 2 Ball bearing 2a Outer ring 2b Inner ring 3 Main body frame 4 Wheel 5 Turning part 7 Shaft hole 8 Support wheel 11 Axle 12 Ball bearing 12a Outer ring 12b Inner ring 13 Wheel 15 Shaft hole 16 Support ring _Wo width W _s width S ₁ axis Fulcrum S _2- axis fulcrum T _o thickness T _s thickness

Claims (5)

A main body frame (3) made of synthetic resin in which a support shaft (1) and a ball bearing (2) for supporting the support shaft (1) are insert-molded, and the main body frame (3) are supported. A wheel (4) is provided, and a shaft hole (7) into which the support shaft (1) is inserted in the center of the swivel part (5) of the main body frame (3) is formed so as to penetrate vertically. A support ring (8) having a width (W _s ) narrower than the width (W _o ) of the outer ring (2a) is press-fitted into the outer periphery of the outer ring (2a) of the ball bearing (2), and the outer ring (2a) Insert molding is performed so that the upper and lower surfaces, the outer peripheral surface, and the entire support ring (8) are embedded in the main body frame (3), and the insert bearing is held on the inner peripheral portion of the shaft hole (7). A caster characterized in that the inner ring (2b) of 2) is fixed to the support shaft (1). Pivotal point (S ₁₎ and the wheel (4) caster according to claim 1, characterized in that it is assumed that the pivotal point (S ₂₎ is shifted in the longitudinal direction of the support shaft (1). The wheel (4) includes an axle (11) and a synthetic resin wheel (13) in which a ball bearing (12) for supporting the axle (11) is insert-molded, and the axle is disposed at the center of the wheel (13). It is assumed that a shaft hole (15) into which (11) is inserted is formed to penetrate in the left-right direction, and the outer circumference of the outer ring (12a) of the ball bearing (12) is formed from the width (W _o ) of the outer ring (12a). Insert molding so that the support ring (16) having a narrower width (W _s ) is press-fitted, and the left and right side surfaces and outer peripheral surface of the outer ring (12a) and the entire support ring (16) are embedded in the wheel (13). And it hold | maintains at the inner peripheral part of the shaft hole (15) of the said wheel (13), and also has fixed the inner ring | wheel (12b) of the said ball bearing (12) to the said axle shaft (11). Key according to claim 1 Justice. The caster according to claim 1, wherein the width (W _s ) of the support wheel (8) is set to be ½ or less of the width (W _o ) of the outer ring (2a). The caster according to claim 3, wherein the width (W _s ) of the support ring (16) is set to be ½ or less of the width (W _o ) of the outer ring (12a).

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