JP2009154635A - Buffer caster - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shock absorption caster capable of absorbing a shock without making a lower fork inhibited from swinging to an upper fork even when a heavy article is loaded on a vehicle body. <P>SOLUTION: The shock absorption caster 1 includes: a fork, which is divided into the upper fork 2 and a lower fork 3; a swinging center shaft, which supports the lower fork 3 pivotally to the upper fork 2 as the center of the swinging; a shock absorption member 5, one end of which is mounted to the upper form 2 and the other end of which is mounted to the lower fork 3; a wheel 6, which is supported rotatably to the lower fork 3; and a bearing 7, which is provided between the upper form 2 or the lower fork 3 and the swinging center shaft. The lower fork 3 swings smoothly to the upper fork 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a buffer caster suitable as a wheel for a truck for various transports, and more particularly to a buffer caster suitable for a wheel for a truck for transporting heavy objects.

  The caster has a shock absorbing mechanism for absorbing and softening the shock because the wheel is accompanied by an impact when the wheel rotates on the road surface or the floor surface and goes down the step or climbs over the step.

As a buffer caster provided with such a buffer mechanism, a buffer caster 101 of JP-A-2005-88846 has been proposed.
As shown in FIG. 5, the buffer caster 101 includes a fork 102 that is divided into an upper fork 102a and a lower fork 102b, and a coil spring 103 that can be expanded and contracted between the upper fork 102a and the lower fork 102b. In addition, a shaft support hole is provided in each of the upper fork 102a and the lower fork 102b, and a shaft 104 that supports both of the shaft support holes is provided so that the lower fork 102b can swing relative to the upper fork 102a. A wheel 105 is pivotally supported at a lower portion of the fork 102b.
When the wheel 105 receives an external force, the lower fork 102 b rotates, but the shock is absorbed by the coil spring 103.
JP-A-2005-88846

However, when a heavy object is placed on the vehicle body to which the buffer caster 101 is attached, a large load is applied to the shaft 104 that pivotally supports the upper fork 102a and the lower fork 102b, and the shaft 104 and the upper fork 102a. And the frictional force between the shaft support hole of the lower fork 102b increases.
As a result, the swinging of the upper fork 102a with the lower fork 102b is hindered, and there is a problem that the shock cannot be absorbed.

  In view of the above, it is an object of the present invention to provide a shock absorber that can absorb an impact without disturbing the swinging of the lower fork even when a heavy object is placed on the vehicle body. And

  In order to solve the above-mentioned problem, a shock absorber according to claim 1 includes a fork that is divided into an upper fork and a lower fork, and a lower fork that is swingably supported with respect to the upper fork. In a shock-absorbing caster comprising a central swing center shaft, a shock-absorbing member having one end attached to the upper fork and the other end attached to the lower fork, and a wheel pivotally supported by the lower fork A bearing is provided between the upper fork or the lower fork and the swing center shaft so that the lower fork swings smoothly with respect to the upper fork.

  The shock-absorbing caster according to claim 2 comprises a rolling bearing having a bearing having an outer ring, an inner ring, and a rolling element between the outer ring and the inner ring, the inner ring being fixed to the swing center shaft, and the outer ring being fixed to the lower fork. The swinging center shaft is fixed to the upper fork in the vicinity of both ends.

  The shock absorber of claim 3 comprises a rolling bearing having a bearing having an outer ring, an inner ring, and a rolling element between the outer ring and the inner ring. The inner ring is fixed to the swing center shaft, and the outer ring is fixed to the upper fork. The swinging center shaft is fixed to the lower fork in the vicinity of both ends.

  According to a fourth aspect of the present invention, the shock absorber is a cylindrical coil spring, and the upper fork and the lower fork each have opposing surfaces that substantially oppose the traveling direction of the shock caster, and these surfaces face each other. Protruding protrusions are provided, and with the protrusions inserted into the cylindrical coil spring, both ends of the cylindrical coil spring are opposed to the upper and lower forks, respectively, by the urging force of the cylindrical coil spring. The cylindrical coil spring is attached to the upper fork and the lower fork by being pressed by.

  According to a fifth aspect of the present invention, the buffer caster is provided with a swing restricting means for restricting the swing width of the lower fork between the upper fork and the lower fork.

  According to a sixth aspect of the present invention, the rocking caster includes a swing restricting means, and a locking hole is formed in the upper fork, and a part of an arc centering on the swinging central axis is formed in the lower fork. A curved long hole is formed as a shaft, and a locking pin is inserted into both the holes.

  According to a seventh aspect of the present invention, the buffer caster is formed at a position where the locking hole of the upper fork and the long hole of the lower fork are opposed to each other in the axle direction. It penetrates.

  According to the shock absorber of claim 1, the bearing is provided between the upper fork or the lower fork and the swinging central shaft, so that even when a heavy object is placed on the vehicle body, The lower fork can swing smoothly and absorb the impact.

According to the shock absorber of the second aspect, the inner ring of the rolling bearing is fixed to the swing center shaft, the outer ring is fixed to the lower fork, and the swing center shaft is fixed to the upper fork in the vicinity of both ends.
Thereby, the frictional force between the oscillation center shaft and the lower fork can be reduced.

According to the shock absorber of the third aspect, the inner ring of the rolling bearing is fixed to the swing center shaft, the outer ring is fixed to the upper fork, and the swing center shaft is fixed to the lower fork in the vicinity of both ends.
Thereby, the frictional force between the oscillation center shaft and the upper fork can be reduced.

According to the buffer caster of the fourth aspect, the cylindrical coil spring can be attached to the upper fork and the lower fork using the urging force of the cylindrical coil spring that is the buffer member.
Furthermore, since the cylindrical coil spring can be easily removed when replacing the cylindrical coil spring, the buffer load of the buffer caster can be easily changed.
Further, since the protrusions of the cylindrical coil spring are inserted, both ends of the cylindrical coil spring can be prevented from being displaced from predetermined positions on the opposing surfaces of the upper and lower forks.

  According to the buffer caster of the fifth aspect, the rocking width of the lower fork can be regulated by providing the rocking regulating means.

According to the buffer caster of the sixth aspect, the swinging can be restricted by the locking hole provided in the upper fork, the long hole provided in the lower fork and the locking pin.
Therefore, the swinging of the lower fork can be restricted with a simplified structure, and plastic deformation of the coil spring, damage to other members, and the like can be prevented.

  According to the buffer caster of the seventh aspect, since one locking rod is inserted through the locking hole and the long hole, it is possible to prevent the lower fork from being twisted excessively with respect to the upper fork.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
FIG. 1 is a side view of a buffer caster 1 according to an embodiment of the present invention. The buffer caster 1 is attached to a vehicle body (not shown) such as a carriage.
FIG. 2 is a partial cross-sectional side view of the buffer caster 1 according to an embodiment of the present invention.
In the following description, the direction of arrow A in FIG.

  The buffer caster 1 includes a fork that is divided into an upper fork 2 and a lower fork 3, and a lower fork 3 that is swingably supported with respect to the upper fork 2. A bolt 41 which is a part of the shaft 4, a cylindrical coil spring 5 which is a buffer member having one end attached to the upper fork 2 and the other end attached to the lower fork 3 (see FIG. 2), and the lower fork 3 And a wheel 6 that is pivotally supported by the wheel.

  The upper fork 2 is formed by plastically processing a single metal plate, and a pair of hanging plates 22 formed integrally with the top plate 21 so as to face the axle direction. It is composed of a top plate 21 and a pair of hanging side plates 22 and a hanging front plate 23 formed so as to be substantially perpendicular to the traveling direction of the buffer caster.

The top plate 21 is provided with a vehicle body attachment portion 9 for attaching the buffer caster 1 to the vehicle body.
The vehicle body attachment portion 9 includes a pivot shaft 91, a mounting plate 92 fixed to the upper portion of the pivot shaft 91, and a bearing cover 93 that is in contact with the bottom surface of the mounting plate 92.
As shown in the cross-sectional view of FIG. 2, the pivot shaft 91 passes through the top plate 21, and a bearing 94 is interposed between the lower peripheral surface of the pivot shaft 91 and the inner surface of the top plate 21. Yes.
A bearing 95 is interposed between the inner surface of the bearing cover 93 and the upper surface of the top plate 21.
With such a configuration, the upper fork 2 of the buffer caster 1 can turn around the turning shaft 91.
By providing the bearing 94 and the bearing 95, the upper fork 2 of the shock caster 1 can smoothly turn around the turning shaft 91 even when a heavy object is placed on the vehicle body.

A central hole 24 is formed in the vicinity of the lower end of each drooping side plate 22 to allow a bolt 41 that is a part of the swinging central shaft 4 to pass therethrough (see FIG. 1).
The swing center shaft 4 includes a bolt 41, a washer 42 described later, and a nut 43 described later (see FIG. 4).

Further, a locking hole 25 for allowing the swing limit bolt 8 that is a rod to pass through is formed substantially above the center hole 24 of each drooping side plate 22.
The swing restricting means includes the swing restricting bolt 8, the locking hole 25, a long hole 35 of the lower fork 3 described later, a washer (not shown), and a nut (not shown).

On the inner surface of the drooping front plate 23, which is the surface facing the upper fork 2, a protrusion 26 is provided that protrudes in a direction substantially opposite to the traveling direction of the shock absorber 1.
One end of the cylindrical coil spring 5 is in contact with the inner surface of the drooping front plate 23, and the protrusion 26 is inserted in the long axis direction of the cylindrical coil spring 5.
Thereby, it can prevent that the end of the cylindrical coil spring 5 shifts | deviates from the predetermined position of the drooping front board 23. FIG.

  The lower fork 3 is composed of a pair of side plates 31 opposed to each other in the axle direction of the wheels 6 and a front plate 32 that bridges both side plates 31 by plastic processing a single metal plate.

As shown in FIGS. 2 and 3, a central hole for penetrating the bolt 41 and the rolling bearing 7, which are a part of the swing central shaft 4, is formed on the lower side of each side plate 31 in the traveling direction. Yes.
A shaft support hole 37 for supporting an axle bolt 61 that is an axle of the wheel 6 is formed on the side opposite to the traveling direction of the lower side of each side plate 31.
In each upper part of the side plate 31, a curved long hole 35 is formed which overlaps with the locking hole 25 and has a part of an arc centered on the swinging central axis 4 as a long axis.

The front plate 32 is substantially opposed to the inner surface of the above-described drooping front plate 23, and the surface of the front plate 32 on the traveling direction side of the buffer caster 1 forms the opposed surface of the lower fork 3.
A protrusion 36 that protrudes in the traveling direction of the buffer caster 1 is provided on the surface of the front plate 32 on the traveling direction side of the buffer caster 1.
The other end of the cylindrical coil spring 5 is in contact with the surface of the front plate 32 on the traveling direction side, and the protrusion 36 is inserted in the long axis direction of the cylindrical coil spring 5.
Thereby, it can prevent that the other end of the cylindrical coil spring 5 shifts | deviates from the predetermined position of the front board 32. FIG.

Since the upper fork 2 and the lower fork 3 have the above-described configuration, the cylindrical coil spring 5 can be attached to the upper fork 2 and the lower fork 3 using the urging force of the cylindrical coil spring 5.
Further, when the cylindrical coil spring 5 is replaced, the swing limit bolt 8 is removed, and the lower fork 2 is rotated so that the distance between the hanging front plate 23 of the upper fork 2 and the front plate 32 of the lower fork 3 is increased. By doing so, the cylindrical coil spring 5 can be easily removed.
Therefore, the buffer load of the buffer caster 1 can be easily changed by replacing the cylindrical coil spring 5.

The rolling bearing 7 is a radial ball bearing, and includes an outer ring 71, an inner ring 72, and a spherical rolling element 73 between the outer ring 71 and the inner ring 72, as shown in FIG.
In the present embodiment, the inner ring 72 is fixed to the bolt 41 that is a part of the swing center shaft 4, and the outer ring 71 is fixed to the lower fork 3 with the rolling bearing 7 inserted in the center hole of the lower fork 3. Yes.
The bolt 41 extends from the base end to the tip end in the center hole 24 of one hanging side plate 22 of the upper fork 2 and the inner ring 72 of the rolling bearing inserted in the center hole of one side plate of the lower fork 3. The inner ring 72 of the rolling bearing inserted into the center hole of the other side plate passes through the center hole 24 of the other hanging side plate 22 of the upper fork 2 in this order.

A nut 43 is screwed onto the tip of the bolt 41 with a washer 42 sandwiched between the drooping side plate 22 of the upper fork 2.
The head of the bolt 41 abuts against one of the drooping side plates 22 of the upper fork 2, and the nut 43 and the washer 42 abuts against the other drooping side plate 22 of the upper fork 2. 2 is fixed.

As shown in FIG. 3, the oscillation limiting bolt 8 that is a rod passes through the long hole 35.
From the base end to the tip end, the swing limit bolt 8 has a locking hole 25 of one hanging side plate 22 of the upper fork 2, a long hole 35 of one side plate of the lower fork 3, and the length of the other side plate of the lower fork 3. The hole 35 passes through the locking hole 25 of the other hanging plate 22 of the upper fork 2.
A state nut (not shown) in which a washer (not shown) is sandwiched between the drooping side plate 22 of the upper fork 2 is screwed to the tip of the swing limit bolt 8.

FIG. 2 shows a state in which no impact is applied to the wheel 6, and the swing limiting bolt 8 is in contact with the end of the elongated hole 35 on the traveling direction side.
FIG. 3 shows a state in which an impact is applied to the wheel 6, and the swing limit bolt 8 is in contact with the end of the elongated hole 35 on the opposite side in the traveling direction.

In the present embodiment, the inner ring 72 is fixed to the bolt 41 that is a part of the swing center shaft 4, and the outer ring 71 is fixed to the lower fork 3 with the rolling bearing 7 inserted in the center hole of the lower fork 3. However, the present invention is not limited to this. For example, the inner ring 72 may be fixed to the bolt 41 that is a part of the swing center shaft 4, and the outer ring 71 may be fixed to the upper fork 2.
In this case, the bolt 41 which is a part of the swing center shaft 4 is fixed to the lower fork 3 in the vicinity of both ends.

  In the present embodiment, the locking hole 25 of the upper fork 2 and the long hole 35 of the lower fork 3 are formed at positions facing each other in the axle direction, and one locking hole 25 and one long hole 35 are provided. Although the description has been given of the case where the rocking limit bolt 8 that is a locking rod is penetrating, the present invention is not limited to this, and for example, independent locking pins are provided in the locking holes 25 on both sides of the wheel, The rocking of the lower fork 2 may be restricted by the locking pins passing through the long holes 35.

  In this embodiment, although the case where the rolling bearing 7 was a radial ball bearing was demonstrated, it is not limited to this, For example, the rolling bearing 7 may be a thrust ball bearing, a radial roller bearing, and a thrust roller bearing. .

  In the present embodiment, the case where the upper fork 2 of the buffer caster 1 is rotatable about the swing shaft 91 has been described. However, the upper fork 2 of the buffer caster 1 is not limited to this, and the vehicle body attachment portion is used. It may be fixed to 9 and cannot turn.

It is a side view of the buffer caster which is one Embodiment of this invention. It is a partial cross section side view of buffer caster 1 which is one embodiment of the present invention, and shows the state where shock is not applied to wheel 6. It is a partial cross section side view of buffer caster 1 which is one embodiment of the present invention, and shows the state where an impact is applied to wheel 6. It is sectional drawing of the major axis direction of a rocking | fluctuation center, and shows the positional relationship of the rocking | swiveling center axis | shaft 4, the upper fork 2, the lower fork 3, and the rolling bearing 7. FIG. It is a side view of the conventional buffer caster.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Buffer caster 2 Upper fork 3 Lower fork 4 Oscillation center shaft 5 Coil spring 6 Wheel 7 Rolling bearing 8 Oscillation restriction bolt 9 Car body attachment part 21 Top plate 22 Hanging side plate 23 Front hanging plate 24 Center hole 25 Locking hole 26 Protrusion 31 Side plate 32 Front plate 35 Long hole 36 Protrusion 37 Shaft support hole 41 Bolt 42 Washer 43 Nut 61 Bolt 71 Outer ring 72 Inner ring 73 Rolling body 91 Rotating shaft 92 Mounting plate 93 Bearing cover 94 Bearing 95 Bearing 101 Buffer caster 102 Fork 102a Upper fork 102b Lower fork 103 Coil spring 104 Shaft 105 Wheel

Claims (7)

A fork divided into an upper fork and a lower fork,
A lower fork is swingably supported with respect to the upper fork, and a swing center axis that is the center of the swing,
A buffer member having one end attached to the upper fork and the other end attached to the lower fork;
In a shock absorber having a wheel pivotally supported on the lower fork,
A shock absorber, wherein a bearing is provided between an upper fork or a lower fork and a swing central shaft, and the lower fork swings smoothly with respect to the upper fork. The bearing comprises a rolling bearing having an outer ring, an inner ring, and rolling elements between the outer ring and the inner ring,
2. The shock absorber according to claim 1, wherein the inner ring is fixed to the swing center shaft, the outer ring is fixed to the lower fork, and the swing center shaft is fixed to the upper fork in the vicinity of both ends. The bearing comprises a rolling bearing having an outer ring, an inner ring, and rolling elements between the outer ring and the inner ring,
2. The shock absorber according to claim 1, wherein the inner ring is fixed to the swing center shaft, the outer ring is fixed to the upper fork, and the swing center shaft is fixed to the lower fork near both ends. The buffer member is a cylindrical coil spring,
The upper fork and the lower fork each have opposed surfaces that are substantially opposed to the traveling direction of the buffer caster, and the protrusions that protrude so as to face each other are provided on these surfaces,
In a state where the projections are inserted into the cylindrical coil spring, both ends of the cylindrical coil spring are pressed against the opposing surfaces of the upper and lower forks by the urging force of the cylindrical coil spring, respectively. 4. The shock absorber according to claim 1, wherein a coil spring is attached to the upper fork and the lower fork.   The shock absorber according to any one of claims 1 to 4, wherein a swing restricting means for restricting a swing width of the lower fork is provided between the upper fork and the lower fork.   The swing restricting means is formed with a locking hole formed in the upper fork, and a curved long hole whose main axis is a part of a circular arc centering on the swinging central axis. 6. The shock absorber caster according to claim 5, wherein the shock absorber caster is formed, and a locking pin is inserted into both the holes.   The locking hole of the upper fork and the long hole of the lower fork are formed at positions facing each other in the axle direction, and a single locking rod passes through the locking hole and the long hole. The buffer caster according to claim 6.

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