JP5137718B2 - caster - Google Patents

Description

  The present invention relates to a caster provided at a lower portion of a carriage or the like.

2. Description of the Related Art Conventionally, casters provided in a lower part of a cart or the like are known in which a bearing that is rotatable around a vertical axis is interposed in order to smoothly turn a wheel. For example, as described in Patent Document 1, a bearing case member in which a bearing is interposed is fixed to a yoke frame on which a wheel is pivotally attached.
JP-A-11-245607

  However, if a bearing case member is used, a process of interposing the bearing in the case member and a process of fixing the case member in which the bearing is interposed to the yoke frame are necessary, which takes time and labor to manufacture. was there. In addition, there is a problem that the cost for manufacturing the case member is high. Further, a space for fixing the bearing case member is required, and it is difficult to reduce the size of the yoke frame.

Accordingly, an object of the present invention is to provide a caster that can easily hold a bearing on a yoke frame, can be quickly manufactured, and can be downsized .

In order to achieve the above object, a caster according to the present invention includes a pedestal, a yoke frame pivotally attached to the pedestal via a bearing so as to be pivotable about a vertical axis, and a horizontal axis around a lower end of the yoke frame. A caster having a wheel pivotably attached to the yoke frame, wherein the yoke frame has a pair of support legs for pivotally attaching the wheels, and the support legs cross the upper end. A support wall portion having a circular arc shape, and further having an arc-shaped holding protrusion between the pair of support legs as viewed from the bottom surface, and the support wall portion of the yoke frame and the circle The outer ring of the bearing is directly fitted into the circular fitting space formed by the arc-shaped holding projection piece.

  Further, the holding projecting piece has a claw portion that is bent radially inward of the vertical axis and prevents the bearing from coming out downward.

  Further, the support leg is provided with a rear bent leading end portion for pivotally supporting the wheel at the lower end, and, except for the front end portion, the support leg is formed on the inner surface of the support wall portion having an arcuate cross section. The first radial dimension and the second radial dimension have the inner surface of the second radial dimension that is the same as the first radial dimension, and an intermediate portion having a circular cross section with the vertical axis as a common center point. The outer peripheral radius of the outer ring of the bearing is set.

  According to the caster of the present invention, since the bearing can be attached to the yoke frame without using a bearing case member, the number of assembling steps can be reduced. Further, the number of parts can be reduced, and the structure can be simplified. A space for mounting the bearing case member is not required, and the size can be reduced.

Hereinafter, the present invention will be described in detail with reference to the drawings illustrating embodiments.
FIG. 1 is a view showing an embodiment of a caster according to the present invention, in which (a) is a side view and (b) is a rear view. Moreover, FIG. 2 is principal part sectional drawing of one Embodiment, (a) is side sectional drawing, (b) is a partially broken rear view. FIG. 3 is a cross-sectional view taken along the line AA in FIG.

The caster of the present invention includes a pedestal 1 fixed to the bottom of a trolley, a transporting and conveying device (attached body), and a yoke frame 2 pivotally attached to the pedestal 1 so as to be pivotable about a vertical axis L _1. The wheel 3 is pivotally attached to the yoke frame 2 so as to be rotatable about a horizontal axis L ₂ , and the pedestal 1 and the yoke frame 2 are pivotally attached to the vertical axis L ₁ via a bearing 5. And a swivel shaft 6. The bearing 5 is a deep groove ball bearing.
In the present invention, the direction will be described based on the posture in use. The floor on which the wheel 3 rolls or the ground side is referred to as the lower side. The opposite of the direction of travel in the use posture is referred to as the rear.

The yoke frame 2 has the outer ring 51 of the bearing 5 directly fitted to the upper end portion. A pair of support legs 20, 20 are provided for pivotally attaching the wheel 3 to the lower end. The support legs 20, 20 have support wall portions 21, 21 having an arcuate cross section centered on the vertical axis L ₁ at the upper end. Further, the position forming the support legs 20 and 90 degrees when viewed from the bottom, has a pair of cross-sectional arc-shaped curved holding protrusion 24, 24 with a focus point of the vertical axis L _1. One metal plate-like member having a substantially uniform thickness is molded by pressing or the like. It has a substantially uniform wall thickness (wall thickness). Note that “directly” is a state in which the outer ring 51 and the yoke frame 2 are fitted without any other member interposed therebetween. More specifically, the outer peripheral surface 51a of the outer ring 51 is in contact with and fitted to the yoke frame 2.

The yoke frame 2 forms a circular fitting space portion 25 by the support wall portions 21 and 21 and the arc-shaped holding projection pieces 24 and 24. That is, surrounded by four transverse cross section an arcuate wall portion which is formed every 90 ° a common center point as the vertical axis L ₁ (a pair of support wall portions 21, 21 and a pair of holding projecting pieces 24, 24) A circular fitting space 25 serving as a storage portion (case portion) for the bearing 5 is formed.
Further, the support wall portions 21 and 21 and the holding projecting pieces 24 and 24 are connected in a circumferential direction by a cross-section arc-shaped connection portion centering on the vertical axis L ₁ on the upper end side, and the cylindrical wall portion 28. Is forming. The cylindrical wall portion 28 surrounds the upper end side of the circular fitting space portion 25 around the vertical axis L ₁ . A case portion for holding (accommodating) the bearing 5 in the yoke frame 2 is integrally formed as a circular fitting space portion 25.

The first radius dimension R ₁ of the inner surface of the support wall 21 and the third radius dimension R ₃ of the inner surface of the holding projection piece 24 are set to be equal to the outer peripheral radius dimension R ₀ of the bearing 5. A bearing 5 is interposed in the circular fitting space 25, and the outer ring 51 of the bearing 5 is fitted directly.
The first and third radius dimensions R ₁ and R ₃ are set to be equal to the outer peripheral radius dimension R _0. The outer ring 51 of the bearing 5 is in close contact with the inner surface of the support wall 21 and the inner surface of the holding protrusion 24. It is a dimension that does not idle.

In addition, the support legs 20 and 20 are provided with a rear bent distal end portion 23 that pivotally supports the wheel 3 at the lower end. It is formed horizontal axis L ₂ and concentric through-hole 23a in the tip 23. The wheel 3 is pivotally attached to the tip 23 through a through hole 23a. It can be said that the support leg 20 is formed in an L-shape that bends backward.

The support leg 20 has a cross-section arc-shaped intermediate portion 22 having an inner surface with a second radial dimension R _{2 that} is the same as the first radial dimension R ₁ of the inner surface of the support wall portion 21 except for the distal end portion 23. . The second radius dimension R ₂ is centered on the vertical axis L ₁ . The intermediate portion 22 is formed in a circular arc shape having a cross section having the vertical axis L ₁ as a central point common to the support wall portion 21. In other words, it can also be said that the intermediate portion 22 has a wall portion that extends downward while the support wall portion 21 has an arcuate cross section (extends linearly). Further, the distal end portion 23 has a horizontal axis L ₂ and concentric through-hole 23a.

Further, the first radius dimension R ₁ of the inner surface of the support wall portion 21 and the second radius dimension R ₂ of the inner surface of the intermediate portion 22 are set to the outer peripheral radius dimension R ₀ of the outer ring 51 of the bearing 5. The bearing 5 is formed in a size capable of being press-fitted or loosely fitted. That is, at the time of assembly, the intermediate part 22 moves the bearing 5 concentric with the vertical axis L ₁ linearly from below between the pair of intermediate parts 22, 22, and the support wall parts 21, 21 and The holding protrusions 24 and 24 are formed (set) so that the bearing 5 can be fitted. The support wall portion 21 is formed (set) so that the rotation axis of the bearing 5 is greatly decentered with respect to the vertical axis L ₁ so that the yoke frame 2 cannot turn smoothly. In order to allow the bearing 5 to pass through the intermediate portion 22 smoothly, the intermediate portion 22 is formed to slightly extend from the support wall portion 21 (within the range of press-fitting or loose fitting). May be.

Holding protrusion 24 is in a state of interposing the bearing 5 in the circular fitting space 25, and has a bent are claw portion 24a in the radial inner side of the vertical axis L _1.
The claw portion 24a is in contact with the lower surface 51b of the outer ring 51 of the bearing 5 and holds the bearing 5 in the annular fitting space 25 in a state where the inner ring 52 of the bearing 5 is rotatable. The bearing 5 is prevented from falling off from the circular fitting space 25. The bearing 5 is interposed in the circular fitting space 25 and is provided in a suspended manner at the lower end of the holding projection piece 24 before being bent (before assembly is completed), and the circular fitting space 25 Is formed in a circular cross section in the lower part of the opening.

  The yoke frame 2 has an inner wall-like ceiling wall portion 26 that forms the ceiling portion of the circular fitting space 25 at the upper end of the yoke frame 2. The ceiling wall portion 26 is in contact with the upper surface 51c of the outer ring 51 of the bearing 5 and prevents (blocks) the bearing 5 from coming off upward. In other words, it can be said that the upper end of the yoke frame 2 has a ceiling wall portion 26 in which a through hole 27 is formed so that the pivot shaft 6 can be inserted and the bearing 5 is not pulled upward.

The pedestal 1 is formed by pressing a single rectangular metal plate member by pressing. A yoke frame 2 is pivotally attached to the pedestal 1 via a bearing 5 so as to be pivotable about a vertical axis L ₁ . An outer flange portion 6 a for preventing the pivot shaft 6 from coming into contact abuts, and a recess 1 a is formed in which the upper surface of the pivot shaft 6 and the upper surface of the base 1 are flush with each other. Further, the convex surface 1 b protruding downward by the concave portion 1 a is brought into contact with the upper surface of the inner ring 52 of the bearing 5 through the through hole 27 at the upper end of the yoke frame 2. The pivot 6 is attached to the inner ring 52 of the bearing 5. The pedestal 1 is provided with a plurality of attachment holes for fixing to a non-attachment member (such as a cargo receiving member of a carriage) using a screw member, a nail or the like.

The swivel shaft 6 is inserted through the pedestal 1, the bearing 5 fitted to the yoke frame 2, and the washer member 4 sequentially from above, and the lower end of the swivel shaft 6 is crimped. The base 1 is attached to the upper surface of the inner ring 52 of the bearing 5, and the washer member 4 is attached to the lower surface of the inner ring 52. The yoke frame 2 to which the outer ring 51 of the bearing 5 is fitted is pivotally attached to the pedestal 1 so as to be rotatable about the vertical axis L ₁ . That is, the wheel 3 pivotally attached to the yoke frame 2 of the pedestal 1 can turn around the vertical axis L ₁ .

The operation of the above-described caster of the present invention will be described.
FIG. 4 is an exploded cross-sectional view of the main part before assembly. 5A and 5B are cross-sectional views of the main part of the yoke frame 2 before assembly, where FIG. 5A is a cross-sectional view taken along the line BB in FIG. 4 and FIG. 5B is a cross-sectional view taken along the line CC in FIG.
The yoke frame 2 shown in FIGS. 4 and 5 is in a state before completion of assembly in which the claw portion 24a of the holding projection piece 24 is not bent.

At the time of assembly, the bearing 5 is brought close to the yoke frame 2 from below. Then, the bearing 5 smoothly obstructs the circular fitting space 25 while the rotation axis of the bearing 5 is concentric with the vertical axis L ₁ by the intermediate portions 22 and 22 of the pair of support legs 20 and 20. Guidance (guidance) without letting. The circular fitting space 25 fits the outer peripheral surface 51a of the outer ring 51. The ceiling wall portion 26 abuts on the upper surface 51c of the outer ring 51 of the bearing 5 and prevents upward movement (prevents coming off). In addition, if the intermediate portion 22 of the support legs 20 and 20 is placed along the bearing pressing mold used when the bearing 5 is press-fitted into the circular fitting space 25 (press-fitting process), the bearing 5 is surely fixed to the vertical axis. Press in the direction of the heart L ₁ . Further, the yoke frame 2 can be easily positioned in the press-fitting process.

The bearing 5 is directly fitted on the yoke frame 2. The circular fitting space 25 of the yoke frame 2 holds the inner ring 52 of the bearing 5 so as to be rotatable around the vertical axis L ₁ . In other words, the yoke frame 2 is clamped by four arc wall portions (a pair of support wall portions 21 and 21 and a pair of holding projection pieces 24 and 24) so as to sandwich the outer peripheral surface 51a of the outer ring 51 of the bearing 5 in the radial inward direction. It can be said that it is held in a shape. Therefore, even a small-sized deep groove ball bearing with a small pressing allowance of the upper and lower surfaces 51c, 51b of the outer ring 51 of the bearing 5 (the outer ring 51 is a thin cylindrical shape) can be directly fitted to the yoke frame 2. The yoke frame 2 can be downsized.

Bending the pawl portion 24a of the holding protrusion 24 to the radial inner side of the vertical axis L ₁ (bending step). Since the claw portion 24a is formed on the lower opening side of the circular fitting space 25, the bending mold for bending (for the bending process) is in the same direction as the bearing pressing mold for the press-fitting process. It is possible to press from. That is, it is possible to share the press machine and the holding jig. Furthermore, it is possible to unify the press-fitting process and the bending process.

  The pair of bent claw portions 24a abut against the lower surface 51b of the outer ring 51 of the bearing 5 to prevent downward movement and prevent omission (dropout).

  The turning shaft 6 inserted into the base 1 from above is inserted into the inner ring 52 of the bearing 5 through the through hole 27 at the upper end of the yoke frame 2. The washer member 4 is inserted into the lower end of the inserted turning shaft 6, and the washer member 4 is brought into contact with the inner ring 52 of the bearing 5. The lower end of the pivot shaft 6 is crimped (collapsed deformation) (crimping process). Thus, when the turning shaft 6 is inserted from above, the caulking die can be pressed from the same direction as the bearing pressing die and the bending die. Enables common use of presses and jigs.

When the swivel shaft 6 is crimped, the outer flange portion 6 a of the swivel shaft 6 and the washer member 4 pinch the base 1 and the inner ring 52. The pedestal 1 is attached to the inner ring 52 by the pivot shaft 6. A yoke frame 2 is pivotally attached to the base 1 via a bearing 5 so as to be pivotable. Thereafter, the wheel 3 rotatably pivotally to the horizontal axis L ₂ around a pair of tip portions 23, 23 of the yoke frame 2. The wheel 3 can turn around the vertical axis L ₁ .

After the assembly is completed, the outer surface of the yoke frame 2 excluding the tip 23 is formed in an arc shape with a cross section centered on the vertical axis L _1. Even if it touches an object etc., it enables rolling and turning of the wheel 3 so that it can be smoothly received (not caught).

  For ease of explanation, the operation has been described with the posture in use, but in actual assembly, the top and bottom are turned upside down, and the circular fit is placed on the lower die (base) of the press machine. The space 25 side may be disposed, and the bearing 5 may be press-fitted, the swiveling shaft 6 may be caulked, and the claw portion 24a may be bent using an upper die on the pressing side of the press.

FIG. 6 shows another embodiment. 6A is a side view, and FIG. 6B is a partially broken rear view.
Part of the pair of support legs 20 and 20 is cut out and bent to the bearing 5 side (radial inner side) to form support claws 20a and 20a that prevent the bearing 5 from coming out downward. . The bearing 5 can be held in a hug shape more reliably. In addition, when the support claw 20a is provided, the claw portion 24a of the holding projection piece 24 can be omitted.

FIG. 7 shows another embodiment. Two holding protrusions 24, 24 are provided between the pair of support legs 20, 20 in the circumferential direction. That is, a total of four holding protrusions 24 are provided in the circumferential direction. Each holding protrusion 24 has a claw portion 24a, and holds the bearing 5 in a hug shape more reliably.
In other words, the notch 30 that separates the pair of holding protrusions 24 described in the embodiment into two in the circumferential direction is formed, and four holding protrusions 24 are provided in total. It can be said that the claw portion 24a of the arc-shaped holding projection piece 24 is easily bent.

  In the present invention, the design can be changed, and the pedestal 2 is not limited to a rectangular shape but can be a circular shape or the like. Alternatively, a male screw portion may be formed on the pivot shaft 6 and may be attached to the bearing 5 by screwing together with the nut member. Further, the washer member 4 may be omitted. In addition to the deep groove ball bearing, the bearing 5 may be a roller bearing or the like.

As described above, the present invention includes the pedestal 1, the yoke frame 2 pivotally attached to the pedestal 1 via the bearing 5 so as to be pivotable about the vertical axis L ₁ , and the horizontal axis L at the lower end of the yoke frame 2. _Since the outer ring 51 of the bearing 5 is directly fitted to the upper end portion of the yoke frame 2 in a caster having a wheel 3 pivotably mounted around two, a case member for the bearing is provided. The bearing 5 can be easily attached to the yoke frame 2 without using it. The production and assembly process of the case member for the bearing can be reduced. Production (manufacturing) costs can be reduced. The work time for attaching the bearing 5 to the yoke frame 2 can be reduced, and can be manufactured quickly and easily. The number of parts can be reduced. The space for assembling the bearing case member is not required, and the yoke frame 2 can be made compact. Small and lightweight.

Further, the pedestal 1, the yoke frame 2 pivotally attached to the pedestal 1 via a bearing 5 so as to be pivotable about the vertical axis L ₁ , and the lower end of the yoke frame 2 pivoted about the horizontal axis L _2. In the caster equipped with the wheel 3 attached, the yoke frame 2 has a pair of support legs 20 and 20 for pivotally attaching the wheel 3, and the support legs 20 and 20 are at the upper end. Arc-shaped support wall portions 21 and 21 are further provided, and arc-shaped holding projecting pieces 24 and 24 are disposed between the pair of support legs 20 and 20 in the circumferential direction when viewed from the bottom surface. Since the outer ring 51 of the bearing 5 is directly fitted in the circular fitting space 25 formed by the support walls 21 and 21 of the frame 2 and the arc-shaped holding protrusions 24 and 24, the case member for the bearing is manufactured. And the assembly process can be reduced. The number of parts can be reduced. Production time and assembly time can be reduced and production can be performed quickly and easily. Production costs can be reduced. The yoke frame 2 can be made compact. The outer peripheral surface 51a of the outer ring 51 of the bearing 5 can be fitted. Even in the case of a small-sized deep groove ball bearing with a small pressing allowance for the upper and lower surfaces 51c, 51b of the outer ring 51 of the bearing 5 (a cylindrical shape with a thin outer ring), the outer peripheral surface 51a is held by the circular fitting space 25. Can be used. In addition, if a deep groove ball bearing is used, noise reduction can be improved, and it can be used for conveyance equipment (trolley etc.) for carrying in to the store of the business of the night where quietness is desired, and carrying in in the medical field. The shape of the yoke frame 2 can be simplified and can be manufactured easily and quickly without the need for complicated bending and drawing. Can be manufactured at low cost. A housing portion (circular fitting space portion 25) of the bearing 5 can be formed integrally with the yoke frame 2. The storage part (circular fitting space part 25) can be made strong.

Further, the holding projecting piece 24 is bent radially inward of the vertical axis L ₁ and has a claw portion 24 a that prevents the bearing 5 from coming out downward. It is possible to prevent the bearing 5 from falling off. The bearing 5 can be interposed in the circular fitting space portion 25 from below and can be prevented from dropping downward. The step of fitting the bearing 5 and the step of bending the claw portion 24 can be performed from the lower side coaxially with the vertical axis L ₁ . The lower surface 51b of the outer ring 51 can be held. The bearing 5 can be fitted in a hug shape. The holding strength of the bearing 5 can be improved.

Further, the support leg 20 is provided with a rear bent distal end portion 23 that pivotally supports the wheel 3 at the lower end, and except for the distal end portion 23, the support leg 20 is formed on the inner surface of the support wall portion 21 having an arcuate cross section. having a cross section arcuate intermediate portion 22, the common center point in the vertical axis L ₁ has a first radial dimension R ₁ and the same second radius inner surface dimension R _2, first radial dimension R ₁ Since the second radius R ₂ is set to the outer radius R ₀ of the outer ring 51 of the bearing 5, the bearing 5 is directly fitted to the yoke frame 2 from below (interposed to the circular fitting space 25). be able to. It is possible to prevent the bearing 5 from interfering with the support leg 20 during assembly. The bearing 5 can be positioned smoothly and easily. The intermediate portion 22 can be guided (guided) to the circular fitting space portion 25 without being twisted with the rotational axis of the bearing 5 substantially aligned with the vertical axis L ₁ . Except for the rear bent tip 23, the outer periphery of the yoke frame 2 has an arc shape, and can be prevented from being caught by a path (running path) -like obstacle during turning or traveling. The shape of the yoke frame 2 can be simplified and can be manufactured easily and quickly without the need for complicated bending and drawing. Can be manufactured at low cost. A mold for manufacturing the yoke frame 2 can be easily manufactured.

It is a figure which shows one Embodiment of the caster of this invention, (a) is a side view, (b) is a rear view. It is principal part sectional drawing of one Embodiment, (a) is side sectional drawing, (b) is a partially broken rear view. It is AA sectional drawing of Fig.1 (a). It is a principal part exploded sectional view before an assembly. 5 is a cross-sectional view of a main part of FIG. 4, (a) is a BB cross-sectional view of FIG. 4, and (b) is a CC cross-sectional view of FIG. 4. It is a figure which shows another embodiment, (a) is a side view, (b) is a partially broken rear view. It is a rear view which shows other embodiment.

1 pedestal 2 yoke frame 3 wheel 5 bearing
20 Support legs
21 Support wall
22 Middle part
23 Tip
24 (arc-shaped) holding protrusion
24a Claw
25 Circular fitting space
51 Outer ring L ₁ Vertical axis L ₂ Horizontal axis R ₀ Peripheral radius R ₁ First radius R ₂ Second radius

Claims (3)

A pedestal (1), a yoke frame (2) pivotally attached to the pedestal (1) via a bearing (5) so as to be rotatable about a vertical axis (L ₁ ), and a lower end of the yoke frame (2) And a wheel (3) pivotably mounted around a horizontal axis (L ₂ ),
The yoke frame (2) has a pair of support legs (20) and (20) for pivotally mounting the wheel (3), and the support legs (20) and (20) have a cross section at the upper end. An arc-shaped support wall (21) (21) is provided, and an arc-shaped holding protrusion (24) (24) (between the circumferential direction of the pair of support legs (20) (20) as viewed from the bottom) 24), and in the circular fitting space (25) formed by the support wall portions (21) (21) of the yoke frame (2) and the arc-shaped holding protrusions (24) (24), A caster, wherein the outer ring (51) of the bearing (5) is directly fitted. The holding projecting piece (24) has a claw portion (24a) which is bent radially inward of the vertical axis (L ₁ ) and prevents the bearing (5) from coming out downward. The caster according to claim 1 . The support leg (20) is provided with a rear bent tip (23) that pivotally supports the wheel (3) at the lower end, and, except for the tip (23), the support leg (20) The support wall (21) having an arc-shaped cross section has an inner surface with a second radial dimension (R ₂ ) that is the same as the first radial dimension (R ₁ ) of the inner surface and a common vertical axis (L ₁ ). An intermediate part (22) having a circular arc cross section as a center point, and the first radius dimension (R ₁ ) and the second radius dimension (R ₂ ) are the same as those of the outer ring (51) of the bearing (5). The caster according to claim 1 , wherein the caster is set to an outer peripheral radius dimension (R ₀ ) .

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