JP2014100967A - Wheel supporting structure - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a wheel supporting structure generating little noise, certainly reducing impact force, and capable of smoothly and quietly traveling, with a simple structure.SOLUTION: A wheel supporting structure includes an arm member 1 rotatably supporting a wheel 8, and a supporting member 2 attached to an attached member D. The arm member 1 is rockably journaled to the supporting member 2 with a horizontal journal member 9. The wheel supporting structure also includes a shaft portion 3 provided on either one of the arm member 1 or the supporting member 2, and arranged in parallel at a position eccentric to a journal core L9 of the journal portion 9; and a cylindrical shock absorber 5 held by the other of the arm member 1 and the supporting member 2, and in which the shaft portion 3 is inserted. By rocking around the journal portion 9 of the arm member 1, the shaft portion 3 and the shock absorber 5 are relatively and eccentrically moved, and the shock absorber 5 is elastically deformed to each impact.

Description

  The present invention relates to a wheel support structure.

  Conventionally, a wheel support structure applied to a stretcher used in a medical field, a cart of a manufacturing site such as a medicine or precision electronic equipment, etc., the load is affected by the impact of unevenness of the road surface (wheel contact surface). In order not to receive, the hydraulic damper which relieves an impact was provided (for example, refer to patent documents 1).

JP 2008-190631 A

However, the hydraulic damper has a problem in that it has a large number of parts and assembly man-hours and cannot be manufactured easily and inexpensively.
In addition, the one provided with a compression coil spring instead of the hydraulic damper has a problem that the mounting height from the wheel contact point becomes high because it can be expanded and contracted with a sufficient stroke, which hinders the lowering of the center of gravity of the stretcher and the carriage. It was. In addition, when the spring expands and contracts, there is a problem in that noise such as a metallic sound that the members collide with each other and a spring squeak noise is generated.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a wheel support structure that can smoothly and quietly travel while smoothly reducing impact force and generating no noise while having a simple configuration.

In order to achieve the above object, a wheel support structure of the present invention includes an arm member that rotatably supports a wheel, and a support member that is attached to a mounted member, and the arm member is attached to the support member. In a wheel support structure pivotably mounted at a horizontal pivot part, the wheel support structure is provided on one of the arm member and the support member and is eccentric with respect to the pivot axis of the pivot part. A shaft portion disposed in parallel at a position; and a cylindrical cushioning material that is held by the other of the arm member and the support member and into which the shaft portion is inserted, and the pivot portion of the arm member The shaft portion and the cushioning material are relatively moved eccentrically by swinging around, and the cushioning material is elastically deformed to reduce the impact.
Moreover, the said buffer material is an uneven thickness cylindrical shape where the thickness of the compression plan site | part of a cylinder wall part is larger than the thickness of the non-compression plan site | part.

  ADVANTAGE OF THE INVENTION According to this invention, although it is a simple structure, the impact force generate | occur | produced when a wheel gets over a small protrusion of a road surface, a level | step difference, etc., or falls to a depression or a level | step difference etc. can be relieved reliably. Moreover, it can be easily manufactured with a small number of parts. The appearance is simple and lightweight and compact, and the impact can be mitigated without impairing the aesthetics and functions of the mounted member such as a carriage or stretcher. Moreover, the mounting height dimension from the contact point of a wheel can be made low. Furthermore, no noise is generated and luggage can be conveyed quietly. In particular, it is suitable for a stretcher for transporting a patient at a medical site, a transport of bio-pharmaceuticals, a precision machine and a precision electronic device. Without a special damper member for absorbing the shock, it is easy to assemble and manufacture with a simple structure, and the impact force can be relaxed reliably.

It is a principal part fracture side view of an embodiment of the invention. It is a front view. It is a principal part sectional front view. It is a principal part fracture side view explaining an operation. It is a principal part cross-sectional front view which shows other embodiment. It is a principal part sectional front view showing another embodiment. It is AA sectional drawing of FIG. It is a principal part cross-sectional side view which shows the other example of a shock absorbing material. It is a principal part cross-sectional side view for demonstrating an effect | action. It is a principal part cross-sectional side view which shows another example of a shock absorbing material.

Hereinafter, the present invention will be described in detail based on illustrated embodiments.
As shown in FIGS. 1 and 2, the wheel support structure of the present invention includes a wheel 8 for traveling on a wheel contact surface G such as a road surface or a floor surface, and the wheel 8 around a horizontal pivot axis L8. And a support member 2 attached to a member D to be attached such as a platform of a carriage or a leg of a stretcher, and a pivot attachment between the arm member 1 and the support member 2. By the portion 9, the arm member 1 is swingable about a horizontal pivot axis L9.

  The pivot 9 has a pair of left and right swinging pieces 11, 11 of the arm member 1 disposed at the left and right inner positions of a pair of left and right support pieces 21, 21 of the support member 2. It is pivotally attached by a pivoting shaft member 90 in the shape of a ring.

1 to 3, a shaft portion 3 disposed horizontally (in parallel) at a position away from the pivot attachment portion 9 and provided on the support member 2, and the shaft portion 3 is inserted into the elastic member such as rubber. A cylindrical cushioning material 5 made of a material and a cylindrical holding wall portion 6 provided on the arm member 1 and surrounding and holding the outer peripheral surface 5a of the cushioning material 5 are provided. That is, the shaft portion 3 is arranged at an eccentric position with respect to the pivot axis L9 of the horizontal pivot portion 9.
Further, as shown in the figure, by providing the shaft portion 3 at a position above the pivot attachment portion 9, the space between the wheel 8 and the mounted member D can be effectively utilized without increasing the vertical height. Shock can be mitigated. Further, even if the pair of left and right support pieces 21 and 21 (support member 2) are small in the front-rear direction, the cushioning material 5 and the cylindrical holding wall 6 can be hidden in a side view, and can be made small and excellent in appearance. Although not shown, the shaft 3 may be provided at a position lower than the pivot 9. Moreover, you may provide in the back position etc. rather than the pivot axis L8 of the wheel 8. FIG.

The shaft portion 3 includes an intermediate portion of a shaft member 30 that is constructed so as to connect the pair of left and right support piece portions 21 and 21 in the left-right direction.
The shaft member 30 is, for example, a rivet member that is caulked and fixed to the support piece portion 21, or a bolt member that is fixed to the support piece portion 21 by bolt-nut coupling.

The cylindrical holding wall portion 6 includes a cylindrical intermediate wall portion of a cylindrical member 60 that is installed so as to connect the pair of left and right swing piece portions 11 and 11 in the left-right direction.
The both ends of the cylindrical member 60 are attached to the mounting holes 11a and 11a penetrating the pair of left and right swing piece portions 11 and 11, respectively, so as to fit inside.

The cushioning material 5 is formed in a cylindrical shape having a through hole 51 into which the shaft portion 3 is inserted in a loose fit, and is held by the arm member 1 by being attached to the tubular holding wall portion 6 in an inner fit. Yes.
The inner peripheral surface 51a (of the through hole 51) of the buffer material 5 and the outer peripheral surface of the shaft portion 3 are not integrated. That is, the buffer material 5 and the shaft portion 3 are not fixed (not integrated) by adhesive, baking, solidification after vulcanization, fusion, screwing, or the like.
The buffer material 5 has an outer peripheral surface 5a that is in close contact with the inner peripheral surface 6a of the cylindrical holding wall 6 (tubular member 60) by an elastic force, and is attached (held) to the cylindrical holding wall 6 by a frictional force. ing.
The buffer material 5 is preferably made of a material such as a soft resin or rubber that is easily elastically deformed.

Next, the operation of the wheel support structure of the present invention will be described.
As shown in FIG. 1, the wheel 8 rides on an obstacle Ga on the wheel ground contact surface G as shown in FIG. 4 from the reference posture state in which the wheel 8 touches the flat wheel ground contact surface G or travels. In this case, the wheel 8 receives an upward impact force. In response to the impact force of the arm member 1, the swing piece 11 swings around the pivoting portion 9.

  As the swing piece 11 swings, the cushioning material 5 swings around the pivot portion 9 together with the cylindrical holding wall 6. Since the shaft portion 3 is fixed to the support member 2, the cushioning material 5 (the shaft center L5) moves to an eccentric position with respect to the shaft portion 3 (the shaft center L3) in a side view. That is, the shaft part 3 and the cushioning material 5 are in a relative eccentric movement state in which the shaft part 3 and the buffer material 5 are relatively eccentrically moved.

In this relative eccentric movement state, the shock-absorbing material 5 is pressed against the shaft portion 3, and the shock-absorbing material 5 receives a pressing force from the radial inner side to the outer side. A part of the cylindrical wall portion 52 of the cushioning material 5 is elastically deformed, and the impact force from the wheel 8 and the swinging piece portions 11 and 11 is alleviated. In particular, by elastically compressing a part of the buffer material 5 (portion Y ′ in FIG. 4) in the radial direction, the impact force is not directly transmitted from the arm member 1 to the support member 2 but is relaxed (damped). ing.
Further, when the arm member 1 returns to the reference posture after passing through the obstacle Ga, since the shaft portion 3 is surrounded by the buffer material 5, the contact sound between the hard members (the arm member 1 and the support member 2). It returns smoothly and quietly without generating noise.

  In addition, the buffer material 5 is protected by the cylindrical holding wall 6 and can be protected from external oil stains and direct sunlight, preventing deterioration and improving durability (long life). It prevents the entry of foreign matter and the failure. Further, the shock-absorbing material 5 is hardly exposed, and impact and noise can be prevented with a simple appearance without impairing the beauty.

Further, in the reference posture state (FIG. 1), the distance from the pivot axis L9 to the axis L3 of the shaft portion 3 and the axis L5 of the cushioning material 5 from the pivot axis L9 to the wheel in a side view. Since the shaft portion 3 and the cushioning material 5 are disposed so as to be shorter than the distance to the pivot axis L8 of 8, the eccentric distance (compression amount) between the shaft portion 3 and the cushioning material 5 is reduced. The shock absorber 5 can be made smaller than the swing distance of the arm member 1 due to the impact force received through the shock absorber 8, and the buffer material 5 can be downsized.
Although not shown in the drawings, when landing on a step or depression, the support member 2 moves so as to sink downward due to the load from the mounted member D, and the arm member 1 swings when viewed from the support member 2. Therefore, the above-described relative eccentric movement state is obtained, and the same impact mitigating action is obtained.
Here, the cushioning material and the cylindrical holding wall are provided concentrically with the pivot shaft member, and the cushion material and the pivot shaft member are integrated (stopped), and the cushion material and the cylindrical retaining wall portion are integrated ( Compared to the case where the shock is reduced by elastic rotational shear deformation of the buffer material, the above-described embodiment is a part where the buffer material 5 receives force from the pivot axis L9 (fulcrum). The distance to (the axial center L3 of the shaft portion 3, the action point) is long, the force applied to the buffer material 5 can be reduced, and the buffer material 5 can be reduced in size and extended in life.

Next, another embodiment will be described. The description of the same configuration as that of the embodiment of FIGS. 1 to 4 is omitted.
In FIG. 5, a cylindrical holding wall 6 is formed integrally with a pair of left and right metal swinging pieces 11 and 11 by plastic working such as pressing, and is annular wall 11d projecting inward in the left and right. , 11d. The swing piece portion 11 may be made of resin and the annular wall portion 11d may be integrally formed by a mold.

  In addition, a projecting end portion of the annular wall portion 11d is provided with a vertical surface-shaped contact wall portion 11e that prevents the cushioning material 5 from moving inward and leftward and rightward. An escape hole 11f through which the shaft portion 3 is inserted is provided in the contact wall portion 11e. The escape hole 11f is formed in a size that does not interfere with the shaft portion 3 when the swing piece 11 swings. In other words, an inner flange-like wall portion is provided at the protruding end portion of the annular wall portion 11d to prevent the buffer material 5 from coming off without interfering with the shaft portion 3 when the arm member 1 is swung.

Two shock-absorbing materials 5 are formed in a short cylindrical shape so as to be held by the pair of left and right oscillating pieces 11 and 11, respectively.
The cylindrical member 60 shown in FIGS. 1 to 4 is unnecessary, and there are few types of parts, which is suitable for mass production.

Next, another embodiment will be described. The description of the same configuration as that of the embodiment of FIGS. 1 to 4 is omitted.
As shown in FIGS. 6 and 7, the arm member 1 is provided with the shaft portion 3, and the support member 2 is provided with the cylindrical holding wall portion 6 to hold the cushioning material 5.
The shaft portion 3 is integrally formed with a pair of left and right metal swinging piece portions 11 and 11 by plastic working such as press working, and is protruded from a short columnar projecting portion 11b and 11b projecting outward in the left and right directions. Become.
The cylindrical holding wall portion 6 includes annular wall portions 21d and 21d that are integrally formed on a pair of left and right support piece portions 21 and 21 by plastic working such as a press and project inward in the left and right directions. The swing piece 11 and the support piece 21 may be made of resin, and the protrusion 11b and the annular wall 21d may be integrally formed by a mold.
Two shock-absorbing materials 5 are formed in a short cylindrical shape, and are provided so as to be held by the support piece portions 21 and 21 of the support member 2, respectively.

The operation of another embodiment will be described.
When the arm member 1 receives an impact force and swings, the shaft portions 3 and 3 swing around the pivot axis L9. The buffer materials 5 and 5 are held by the support member 2 and do not swing. Accordingly, the shaft portion 3 moves so as to press the cushioning material 5 from the radial inner side to the outer side, and in side view, the shaft portion 3 (the shaft center L3 thereof) with respect to the buffer material 5 (the shaft center L5). ) Is arranged at an eccentric position. That is, the shaft portion 3 and the cushioning material 5 move relatively eccentrically.
In this relative eccentric movement state, one portion Y of the buffer material 5 is compressed from the radial inner side to the outer side by the shaft portion 3 (the cylindrical wall portion 52 of the buffer material 5 is elastically deformed), and the wheel 8 and the rocking member are swung. The impact force from the moving piece parts 11, 11 is relaxed and transmitted to the support member 2.

Further, although not shown, another embodiment (modified example of FIG. 5) will be described.
Cylindrical holding wall portions 6 and 6 including annular wall portions 11d and 11d are provided on the pair of left and right swing piece portions 11 and 11 to hold the buffer materials 5 and 5, respectively. The pair of left and right support pieces 21, 21 of the support member 2 is provided with a shaft portion 3 formed of a short cylindrical protrusion integrally formed with the support piece 21 and protruding inward in the left and right directions.

Further, although not shown, another embodiment (modified example of FIG. 6) will be described.
The pair of left and right support piece portions 21 and 21 are provided with cylindrical holding wall portions 6 formed of annular wall portions 21d and 21d to hold the buffer materials 5 and 5, respectively.
Then, the shaft member 30 is suspended from the pair of left and right swinging piece portions 11 and 11, and both end portions of the shaft member 30 are protruded from the left and right outer surfaces of the pair of left and right swinging piece portions 11 and 11. To be the shaft portions 3 and 3.

  Further, as shown in FIG. 4, in the state of relative eccentric movement, the cylindrical wall portion 52 of the cushioning material 5 has a portion (compression portion) Y ′ that receives a pressing force from the shaft portion 3 and a portion from the shaft portion 3. There is a portion (non-compressed portion) K ′ that is not subjected to the pressing force. The part of the point symmetry position of the compression part Y ′ with respect to the axis L5 in the side view is the non-compression part K ′.

  The cushioning material 5 shown in FIG. 8 has an uneven cylindrical shape in which the thickness of the compression-stimulated region Y of the cylindrical wall portion 52 is larger than the thickness of the non-compressed region K in the standard posture state and the free state before mounting. Forming. In the relative eccentric movement state shown in FIG. 9, the compressed portion Y ′ of the cylindrical wall portion 52 has a sufficient thickness than the non-compressed portion K ′, and the compressed portion Y ′ is not easily worn or worn. It is possible to prevent a reduction in impact force mitigating action due to the above.

Further, as is apparent from FIG. 8, it has a circular through hole 51 and a circular outer peripheral surface 5a in a side view, and the center of the outer peripheral surface 5a (at the center of the through hole 51 (center of the inner diameter)) The center of the outer diameter) is arranged to form an uneven wall shape.
Further, like the cushioning material 5 shown in FIG. 10, it has a circular through-hole 51 and a fan-shaped outer peripheral surface in a side view, and the essential (center) of the fan-shaped outer peripheral surface is arranged near the center of the through-hole 51. In addition, the thickness of the compression planned portion Y of the cylindrical wall portion 52 may be formed in a fan-shaped uneven cylindrical shape that is larger than the thickness of the non-compressed planned portion K.

  By adopting an unbalanced cylindrical shape, a sufficient thickness is distributed on the compression side, and problems such as wrinkling, hardening, and wear can be prevented even when subjected to repeated compression force or sudden impact force. Impact mitigating action and durability can be obtained with a small shape (small volume), which can contribute to miniaturization and weight reduction of parts.

  The design of the present invention can be changed. In FIG. 3, the cushioning material 5 is equivalent to the left and right length of the cylindrical holding wall 6, but the right and left length of the cylindrical holding wall 6. One or a plurality of cushioning materials 5 having a smaller left and right length dimension than the length dimension may be provided. Although not shown in the drawings, the outer peripheral surface 5a of the cushioning material 5 may be formed in a non-circular or elliptical shape in a side-by-side shape and in an unevenly cylindrical shape.

In the present invention, the mounted member D is a carriage for transporting luggage or the like, a stretcher for carrying a person, a movable work table, etc. Anything that transports etc. is acceptable. In the illustrated embodiment, the support member 2 is a caster that can rotate around the vertical axis La and the wheel 8 can turn around the vertical axis La. It is good also as what cannot turn around La (fixed caster). In the illustrated embodiment, one wheel 8 is pivotally attached to the support member 2 via the arm member 1, but the number of wheels 8 such as one in which a plurality of wheels 8 are pivotally attached, Arrangement is free.
Further, for ease of explanation, the direction in which the wheel 8 is placed on the horizontal wheel contact surface G is a reference posture, the traveling direction side of the wheel 8 is the front, the wheel contact surface G side is the bottom, Is explained. Therefore, the posture in use is not limited based on the direction. For example, the wheel support structure of the present invention may be applied to a transport carriage or device in which the wheel ground contact surface G is a ceiling surface and the wheels 8 travel on the ceiling surface.

  As described above, the wheel support structure of the present invention includes the arm member 1 that rotatably supports the wheel 8 and the support member 2 that is attached to the mounted member D, and the support member 2 includes the arm member 1. Is provided at one of the swing arm member 1 and the support member 2 and is pivotally mounted on the pivot axis 9 of the pivot 9. A shaft portion 3 disposed in parallel at an eccentric position relative to the arm member 1 and a cylindrical cushioning material 5 that is held on the other of the arm member 1 and the support member 2 and into which the shaft portion 3 is inserted. Since the shaft portion 3 and the cushioning material 5 are relatively moved eccentrically by swinging around the pivoting portion 9 of the member 1, the cushioning material 5 is elastically deformed and the impact is alleviated. When the wheel gets over a small protrusion or step on the road surface, or falls into a depression or step The impact force generated can be reliably relaxed. Moreover, it can be easily manufactured with a small number of parts. The appearance is simple and lightweight and compact, and the impact can be mitigated without impairing the aesthetics and functions of the mounted member such as a carriage or stretcher. The mounting height dimension of the wheel 8 from the ground point can be reduced. When returning to the standard posture, no noise is generated, and it is possible to carry the baggage quietly. In particular, it is suitable for transporting patients at medical sites, transporting bio-pharmaceuticals, precision machinery and precision electronic equipment. The impact force can be reliably relieved with a simple structure without a special damper member for absorbing the shock.

Further, since the buffer material 5 is an uneven cylindrical shape in which the thickness of the compression planned portion Y of the cylindrical wall portion 52 is larger than the thickness of the non-compressed planned portion K, a sufficient thickness is distributed on the compression side, Even when subjected to repeated compressive force or sudden impact force, problems such as plastic deformation, hardening, wear and tear can be prevented. In addition, the impact force can be sufficiently relaxed, the durability is excellent, and the life is long. Alternatively, the parts can be reduced in size and weight.

DESCRIPTION OF SYMBOLS 1 Arm member 2 Support member 3 Shaft part 5 Cushioning material 8 Wheel 9 Pivoting part
52 Cylinder wall D Mounted member Y Compressed part K Non-compressed part L9 Pivot axis

Claims (2)

An arm member (1) for rotatably supporting the wheel (8) and a support member (2) attached to the mounted member (D), the arm member (1) being mounted on the support member (2) ) Is a wheel support structure pivotably pivoted at a horizontal pivot (9),
A shaft portion (1) provided on one of the arm member (1) and the support member (2) and arranged in parallel at a position eccentric to the pivot axis (L9) of the pivot portion (9). 3) and a cylindrical cushioning material (5) which is held on the other of the arm member (1) and the support member (2) and into which the shaft portion (3) is inserted,
Due to the swing of the arm member (1) around the pivot portion (9), the shaft portion (3) and the cushioning material (5) move relatively eccentrically, and the cushioning material (5) is moved. A wheel support structure characterized by being elastically deformed so as to reduce impact.   The wheel according to claim 1, wherein the cushioning material (5) has an uneven cylindrical shape in which the thickness of the compression planned portion (Y) of the cylindrical wall portion (52) is larger than the thickness of the non-compressed planned portion (K). Support structure.

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