JP2001180207A - Suspension unit structure and cushion caster - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a cushion caster elastically swinging along unevenness of a road surface to absorb a shock, and to provide a suspension unit structure allowing wide application and use in assembling of the cushion caster or the like. SOLUTION: In this suspension unit, an outer tube having a circular outer shape is horizontally disposed, while a support-side base is horizontally formed with a circular hollow hole of an internal diameter allowing fitting-in of the outer tube. The outer tube of the suspension unit is fitted in the hollow hole of the base. An end face part of the base is formed with swing original position stoppers abutted on correspondent portions of a fork, and is formed with swing limit position stoppers at the other side positions in swinging angle ranges of the fork. A prestress control mechanism for controlling a magnitude of prestress is installed between the base and the outer tube of the suspension unit.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a moving bed, a wheelchair, a moving table, and other applicable equipment. Not only limited to the assembly of cushion casters and cushion casters that run smoothly while exhibiting the effects of mitigation and noise reduction, but also widely used as a bed structure, chair, table, etc. that does not move, as a leg structure that exhibits vertical cushioning, etc. It belongs to the technical field of suspension unit structures that can be used.

[0002]

2. Description of the Related Art Conventionally, a suspension unit and a suspension unit structure in which the suspension unit is assembled as a mechanism that can be used for various purposes belong to a known art. A cushion caster using the suspension unit structure is also disclosed in, for example, JP-A-6-199.
It is described in Japanese Patent Publication No. 101 and belongs to the public.

[0003]

The conventional suspension unit structure and the cushion caster have a desired function and effect. However, the conventional suspension unit structure and cushion caster have unexpectedly received an excessively large load because, for example, the swing range (swing angle) of the fork of the cushion caster does not have a special regulating element. In such a case, there is a risk that the suspension unit or the fork may be damaged, leading to a failure or an accident. In addition, there is a risk that the stability of a user or a loaded article on an applied device such as a wheelchair or a moving bed using a cushion caster may be impaired.

[0004] Next, since rubber material is used for the restoring force (elasticity) of the suspension unit, when used for a cushion caster, the fork and the wheel bounce up and down little by little due to unevenness of the road surface (floor surface). It is oscillated (vibrated), and the usability as an applied device and the riding comfort are poor.

[0005] Therefore, an object of the present invention is mainly to be used as a main part structure for assembling a cushion caster, and to protect a suspension unit even when an unexpectedly large load is applied, or to secure safety in use of applied equipment. Suspension unit structure,
And a cushion caster using the suspension unit structure.

A second object of the present invention is to make small vibrations converge at an early stage and to use the elastic strength (prestress) of a rubber material which is a main element of a suspension unit.
A suspension unit structure having a mechanism that can be adjusted according to the convenience of use as an applied device, good ride comfort, or a structure that can always keep the cushioning effect in a good state, and the suspension unit structure. The purpose is to provide a cushion caster that is used.

[0007]

According to a first aspect of the present invention, there is provided a suspension unit structure according to the first aspect of the present invention, wherein a suspension unit is relayed from a base on a support side in a predetermined direction. In the suspension unit structure in which the fork on the working side is arranged and the fork swings in accordance with the magnitude of the load on the fork, the outer shape of the outer cylinder of the suspension unit is circular, It is arranged in the horizontal direction, a circular hollow hole having an inside diameter capable of fitting the outer cylinder is formed in the base on the support side in the horizontal direction. The outer cylinder is fitted, and the end face of the hollow hole of the base, which is the support side, A swing limit position stopper for contacting the corresponding portion of the fork is provided at a position on the other side of the angle range in which the fork swings; A prestress adjusting mechanism for adjusting the magnitude of the prestress of the suspension unit by rotating the outer cylinder with respect to the hollow hole of the base is installed between the base on the support side and the outer cylinder of the suspension unit. Are characterized.

According to a second aspect of the present invention, in the suspension unit structure according to the first aspect, the pre-stress adjusting mechanism gradually moves the outer cylinder of the suspension unit to the hollow hole of the base on the support side. It is characterized in that it is configured to rotate and adjust the magnitude of the prestress.

According to a third aspect of the present invention, in the suspension unit structure according to the first aspect, the prestress adjusting mechanism rotates the outer cylinder of the suspension unit continuously with respect to the hollow hole of the base on the support side. In this case, the magnitude of the prestress is adjusted.

According to a fourth aspect of the present invention, in the suspension unit structure according to any one of the first to third aspects, the rotation axis of the rotary damper fixed to the base on the support side is located at the center of the suspension unit. It is characterized in that it is connected to a rotating shaft located there.

According to a fifth aspect of the present invention, in the suspension unit structure according to the first aspect, the swing source position stopper and the swing limit position stopper on the end surface of the hollow hole of the base on the support side are respectively provided. In a fork that rotates about the rotation axis of the suspension unit, two forks are provided at both sides in the same direction so that both sides extending in a diametrical line passing through the center of the rotation axis correspond to the corresponding positions. And

According to a sixth aspect of the present invention, there is provided the cushion caster according to the first to fifth aspects, wherein the base on the support side is a portion to be attached to the chassis, and the fork is arranged obliquely downward. A cushion caster comprising a caster wheel rotatably attached to a tip end of the fork.

According to a seventh aspect of the present invention, in the suspension unit structure, the fork on the working side is arranged in a predetermined direction by relaying the suspension unit from the base on the supporting side, and the load on the fork is reduced. In a suspension unit structure having a configuration in which a fork swings in accordance with the size, a rotation axis of a rotary damper fixed to a base is connected to a rotation axis located at the center of the suspension unit. I do.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS FIGS. 1 to 5 show an embodiment of a cushion caster according to the invention of claim 6, wherein the suspension unit structure according to the invention of claim 1 is assembled as a main part structure. Is shown.

First, as an embodiment of the suspension unit structure, a vertical support shaft (or mounting shaft) 2 as a means (element) for mounting to a chassis of a transport vehicle via a pipe leg 1 when used as a cushion caster is described. The lower end is rotatably (rotatably) attached to a vertical cylindrical portion 4a corresponding to the so-called upper half of the base 4.
Is configured as a pivotable support side. A suspension unit 5 is incorporated in a hollow hole 4c of a horizontal cylindrical portion 4b corresponding to the lower half of the base 4, and the forks 6 on both sides are rotated around a rotation shaft 5a of the suspension unit 5. 6, the fork 6 is arranged in a predetermined direction via the suspension unit 5. Wheel 7 to fork 6
The suspension unit structure is configured such that the fork 6 swings in a range of a fixed swing angle in accordance with the magnitude of the load (see also an exploded view of FIG. 6). ).

In the case of the suspension unit structure of the present invention, the outer cylinder 5b of the suspension unit 5
Has a circular outer shape and is arranged in the horizontal direction.

On the other hand, a circular hollow hole 4c having an inner diameter capable of fitting the outer cylinder 5b of the suspension unit 5 in the horizontal direction is formed in the cylindrical portion 4b of the base 4 on the support side.

The outer cylinder 5 of the suspension unit 5 is inserted into the hollow hole 4c of the cylindrical portion 4b of the base 4.
b is fitted. The tip of a set screw 8 screwed from the outer surface of the cylindrical portion 4b toward the center is formed in the circumferential direction at the center of the outer peripheral surface of the outer cylinder 5b as a means for preventing the suspension unit 5 from coming off from the outer cylinder 5b. Into the annular groove 5d, and the retaining process is performed to the extent that the rotation operation of the outer cylinder 5b is not hindered.

A rocking origin position stopper is provided at both ends of the cylindrical portion 4b of the base 4 on which the hollow hole 4c is formed, on the support side, in which the corresponding portion of the fork 6 normally contacts in the arrangement direction of the fork 6. 9a and 9b are provided, and swing limit position stoppers 10a and 10b are provided at other positions for restricting an angle range in which the fork 6 swings, in contact with a descending part of the fork 6 swinging to the maximum extent. Is provided.

In the case of the illustrated embodiment, the swing source position stoppers 9a and 9b and the swing limit position stoppers 10a and 10b of the base 4 on the support side rotate about the rotation shaft 5a of the suspension unit 5, respectively. In the fork 6, two positions on both sides extending in the direction of the diameter passing through the center of the rotary shaft 5a correspond to the respective positions 11a and 1a.
The swing origin position stoppers 9a and 9b and the swing limit position stoppers 10a and 10b are provided at two locations on both sides in the same diameter line direction so as to be 1b and 12a and 12b (the invention according to claim 5). Therefore, the positioning of the fork 6 at each position is performed firmly and stably at two positions on both sides of the rotation center.

On the premise of the above configuration, two forks 6, 6 are provided on both side end surfaces of the cylindrical portion 4b of the base with the swing origin position stoppers 9a, 9b and the swing limit position stoppers 10a, 10b on both sides. Between the parts (range of the swing angle),
The fork 6 is arranged so that the corresponding positions 11a and 11b and 12a and 12b of the both sides of the fork 6 are accommodated, and at least is connected to the rotating shaft 5a by a set screw 13 screwed from both outer sides toward the center of the rotating shaft 5a. It is attached to rotate integrally. As a means, both ends of the rotary shaft 5a manufactured as a square shaft are made to protrude slightly outward from the end surface of the cylindrical portion 4b of the base 4, as is apparent from the cross section of FIG. It is tightly fitted into the square hole-shaped recess on the fork 6 side.

If the above configuration is maintained (the state of FIG. 3), the fork 6 and the entire suspension unit 5 are in a co-rotating relationship.

Therefore, between the base 4 on the support side and the outer cylinder 5b of the suspension unit 5, the outer cylinder 5b is rotated in a predetermined direction with respect to the hollow hole 4c of the base 4 to reserve the suspension. A pre-stress adjusting mechanism for setting or adjusting the magnitude of the stress is provided as described below, so that a suspension (cushion) function can be achieved (the above is the invention according to claim 1).

In the case of the illustrated embodiment, the pre-stress adjusting mechanism includes four portions obtained by dividing the circumference of the inner peripheral surface of the hollow hole 4c of the cylindrical portion 4b of the base 4 which is the support side into approximately four equal parts. Four key grooves 14 are formed in the axial direction of the position. On the other hand, a total of four key grooves 15 having the same dimensions and specifications as the key grooves 14 are also provided in the axial direction at four positions where the circumference of the outer peripheral surface of the outer cylinder 5b of the suspension unit 5 is divided into approximately four equal parts. I have. Therefore, when the detent key 16 is tightly driven into a square hole formed by matching the two key grooves 14 and 15, the detent key 16 prevents the fork 6 and the suspension unit 5 from rotating together. Become.

The reason for this is that as the structure of the suspension unit 5, a rotary shaft 5a manufactured as a square shaft is inserted into a square hole 17 penetrated in the axial direction of the center of the outer cylinder 5b, and both are rotated. A rubber material 18 of substantially the same shape and the same size as a restoring material is closely inserted and installed in four triangular gaps formed by the two members in such a manner that they are shifted by about 45 ° in angle. Therefore, the four rubber members 18 cooperatively and elastically resist the rotational force acting on the fork 6 and prevent the suspension unit 5 from rotating together with the whole.
At the same time, it exerts elastic suspension and cushioning functions.

The key groove 14 formed in the hollow hole 4c of the cylindrical portion 4b of the base 4 and the key groove 15 formed on the outer peripheral surface of the outer cylinder 5b of the suspension unit 5 are clearly shown in FIG. And one keyway 14 and 15 on the left where the keys 16 are driven by matching each one
Is a common position, the positional relationship between the other key grooves 14 and 15 is counterclockwise in FIG.
It is provided in a displaced arrangement such as 5 °, 10 °, 15 °, and 20 ° in terms of the rotation angle. That is, in FIG. 4, the angle of deviation between the key grooves 14 and 15 at the position where the key 16 is struck is 5 °, so that the rubber material 18 is 5 ° in the normal state.
Minutes of prestress has occurred. However, in FIG.
Keyways 14 and 15 for driving key 16 in a counterclockwise direction
Is changed, the rotation angle is changed to 10 as described above.
Both keyways 14 with ず れ, 15 °, 20 ° misalignment
And 15 are forcibly matched, so that each square rubber material 1
8, a deformation corresponding to the above-mentioned shift angle is forcibly generated. As a result, a pre-stress proportional to the amount of deformation is introduced, and the fork 6 normally stays at the above-described swing source position stoppers 9a and 9b while receiving the action of the pre-stress. However, when the load exceeds the prestress, the fork 6 oscillates (rotates) accordingly and exhibits a cushioning property. Thus, when the position at which the key 16 is hit in the counterclockwise direction in FIG. 4 is sequentially changed, the outer cylinder 5b of the suspension unit 5 is rotated stepwise in a fixed direction to adjust the size of the prestress. The invention according to claim 2).

As an example of use of the suspension unit structure having the above structure, the support shaft 2 is attached to the base 4 and the wheel 7 is attached to the tip of the fork 6 as shown in FIGS. The cushion caster according to the invention can be configured as in the embodiment shown in FIGS. For example, when the cushion caster rides on the convex portion 21 of the floor surface 20 as shown in FIG. 5 (or when the cushion caster is fitted into the concave portion), the fork 6 is displaced by the angle θ and the corresponding free swing The extremely smooth running is realized by the elastic restoring force of the rubber material 18 constituting the suspension unit 5. That is, the riding comfort of a person riding on a transport vehicle or the like using the cushion caster is improved, or the stability of the loaded articles is improved.

In addition, the ride comfort can be further improved by adjusting the magnitude of the pre-stress applied to the rubber member 18 of the suspension unit 5 according to the magnitude of the load assumed in advance. The range in which the fork 5 swings is defined by swing source position stoppers 9a and 9b and a swing limit position stopper 10.
Since they are regulated by a and b, there is no concern about breakage or the like even if an unexpectedly large load is applied. This point
The same applies to the case where it is used as a moving bed or a table leg.

Next, FIGS. 7 and 8 show an embodiment of a suspension unit structure and a cushion caster employing a stepless adjustment type prestress adjusting mechanism according to the third aspect of the present invention.

Although many structures are common to the above-described first embodiment, in the case of the present embodiment, a pocket portion 4e that opens downward is provided at the lower bottom of the cylindrical portion 4b of the base.
The adjusting screw shaft 25 is provided in the pocket portion 4e in a horizontal arrangement in the rotation direction of the rotation shaft 5a of the suspension unit 5.
Is arranged. A yoke 27 having a substantially U-shape is attached downward by a set screw 26 to a lower bottom surface portion of the outer cylinder 5b of the suspension unit 5 exposed to the opening of the pocket portion 4e. A shaft 28 having a female thread rotatable inside the U-shape of the yoke 27 is provided.
The screw shaft 25 for adjustment is screwed in, and both ends of the screw shaft 25 are rotatably supported by the pocket portion 4e.

Therefore, when the adjusting screw shaft 25 is rotated in either the forward or reverse direction, the female screw shaft 28 is moved in the left-right direction in FIG. Then, the yoke 27 and, consequently, the outer cylinder 5b to which the yoke 27 is fixed are rotated in the forward and reverse directions with the movement of the shaft 28 with the female thread, and the relative rotation between the yoke 27 and the rotary shaft 5a is performed as described above. As a result, elastic deformation is forced on the rubber material, and the magnitude of the prestress can be adjusted. In particular, according to the amount of rotation of the adjusting screw shaft 25, the outer cylinder 5b of the suspension unit 5 can be steplessly rotated with respect to the hollow hole of the base 4 on the support side, thereby performing stepless adjustment. Reference numeral 29 denotes the outer cylinder 5
This is a scale plate / opening closing plate which also serves as a scale plate for displaying the rotation angle of b and an opening closing plate closing the downward opening in the pocket portion 4e.

Next, FIG. 9 shows an embodiment of the suspension unit structure and the cushion caster according to the fourth aspect of the present invention.

Also in the case of the present embodiment, many configurations are common to the first embodiment. The feature of this embodiment is that the rotation shaft 31 of the rotary damper 30 fixed to the base 4 on the support side is connected to the rotation shaft 5a located at the center of the suspension unit 5 and rotates integrally therewith. That is being done.

More specifically, the mounting plate 30a of the rotary damper 30 is fixed to the side surface of the base 4 with screws 32, and the rotating shaft 31 manufactured as a square shaft has the same shape as the rotating shaft 5a formed with the same dimensions. Inserted into the square hole.

In the case of the above configuration, since the set screw 13 cannot be employed as in the first embodiment, the fork 6 and the rotating shaft 5a of the suspension unit 5 are connected by the plurality of set screws 33 arranged on the outer periphery of the rotating shaft 31. Joining has been done.

As in the present embodiment, the rotary damper 3
In the case of the suspension unit structure and the cushion caster adopting the fork 6, the damping force similar to a so-called brake acts on the rotation of the rotating shaft 5a.
Swings are converged at an early stage, and a comfortable suspension function is achieved.

[0037]

According to the present invention, the suspension unit structure according to any one of the first to fifth aspects and the cushion caster according to the sixth aspect using the above-mentioned structure unexpectedly become excessive during use. Even when a heavy load is applied, it exerts an excellent effect in protecting the suspension unit or maintaining safety in use of the applied device.

Of course, the suspension unit structure
Not only can it be used as a main structure of a cushion caster, but it can also be widely used for legs, such as a bed, a table, and the like, which prefer cushioning properties.

Further, according to the present invention, there is provided a mechanism capable of adjusting the strength of elasticity of the rubber material, which is a main element of the suspension unit, according to the intended use (application object), and the damping action of the damper is also provided. Since it works, it has the advantage that it can be used while keeping the effect of cushioning (suspension function) always good, as well as excellent usability and ride comfort.

[Brief description of the drawings]

FIG. 1 is a right side view showing an embodiment of a suspension unit structure and a cushion caster according to the first aspect of the present invention.

FIG. 2 is a front half sectional view showing an embodiment of a suspension unit structure and a cushion caster according to the first aspect of the present invention.

FIG. 3 is a front view showing a state in which a detent key is not provided on the suspension unit structure according to the first aspect of the present invention.

FIG. 4 is a front view showing a state before the suspension unit structure according to the first aspect of the present invention rides on a convex portion.

FIG. 5 is a front view showing a state after the suspension unit structure according to the first aspect of the present invention rides on the convex portion.

FIG. 6 is an exploded perspective view of the suspension unit structure according to the first embodiment.

FIG. 7 is a front view showing an embodiment of a suspension unit structure and a cushion caster employing a stepless adjustment type prestress adjusting mechanism according to the invention of claim 3;

FIG. 8 is a bottom view of a main part of a suspension unit structure employing a stepless adjustment type prestress adjusting mechanism according to the third aspect of the present invention.

FIG. 9 is a front view of a suspension unit structure and a cushion caster according to an embodiment of the present invention in a longitudinal half sectional view.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Pipe leg 2 Support shaft 4 Base 4a Tubular part 4b Cylindrical part 4c Hollow hole 5 Suspension unit 5a, 31 Rotating shaft 5b Outer cylinder 6 Fork 7 Wheel 8 Set screw 9a, 9b Swing origin position stopper 10a, 10b Swing limit position Stopper 13, 33 Set screw 14, 15 Key groove 16 Non-rotating key 30 Rotary damper

Claims (7)

[Claims] 1. A structure in which a fork serving as a working side is arranged in a predetermined direction by relaying a suspension unit from a base serving as a supporting side, and the fork swings in accordance with a magnitude of a load on the fork. In the above suspension unit structure, the outer cylinder of the suspension unit has a circular outer shape and is arranged in a horizontal direction. A circular hollow hole having an inner diameter capable of fitting the outer cylinder into a base on the support side. Is formed in the horizontal direction, the outer cylinder of the suspension unit is fitted in the hollow hole of the base, and the end face of the hollow hole of the base, which is the support side, A swing source position stopper for contacting the corresponding portion of the fork is provided, and the corresponding portion of the fork is located at the other side of the angle range in which the fork swings. A pivot limit stopper against which the position contacts is provided, and between the base on the support side and the outer cylinder of the suspension unit, the outer cylinder is rotated with respect to the hollow hole of the base. A suspension unit structure, wherein a prestress adjusting mechanism for adjusting the magnitude of the prestress of the suspension unit is provided. 2. The prestress adjusting mechanism is characterized in that an outer cylinder of a suspension unit is rotated stepwise with respect to a hollow hole of a base, which is a support side, to adjust a size of a prestress. The suspension unit structure according to claim 1, wherein: 3. The prestress adjusting mechanism is characterized in that the prestress is adjusted by rotating the outer cylinder of the suspension unit continuously with respect to the hollow hole of the base on the support side. The suspension unit structure according to claim 1. 4. A rotary shaft of a rotary damper fixed to a base, which is a support side, is connected to a rotary shaft located at the center of the suspension unit.
The suspension unit structure according to claim 1. 5. A swing source position stopper and a swing limit position stopper at an end surface of the hollow hole of the base which is a support side, respectively, are provided at a center of the rotary shaft in a fork which rotates about a rotary shaft of a suspension unit. 2. The suspension unit structure according to claim 1, wherein the suspension unit structure is provided at two positions on both sides in the same direction so that both sides extending in the direction of the diametric line passing therethrough correspond to the corresponding positions. 3. 6. The suspension unit structure according to claim 1, wherein the base on the support side is a portion to be attached to the chassis, the fork is disposed obliquely downward, and the caster wheel is rotated at the tip of the fork. A cushion caster characterized by being freely mounted. 7. A structure in which a fork as a working side is arranged in a predetermined direction by relaying a suspension unit from a base as a supporting side, and the fork swings in accordance with a magnitude of a load on the fork. The suspension unit structure according to claim 1, wherein a rotation axis of a rotary damper fixed to the base is connected to a rotation axis located at the center of the suspension unit.