CN210211903U

CN210211903U - Caster structure

Info

Publication number: CN210211903U
Application number: CN201920623471.6U
Authority: CN
Inventors: Hiroshi Okajima; 冈岛弘; Hayatoshi Ueda; 上田隼利
Original assignee: Kyokuhohu Corp
Current assignee: Kyokuhohu Corp; Takakita Co Ltd
Priority date: 2019-02-20
Filing date: 2019-04-30
Publication date: 2020-03-31
Anticipated expiration: 2029-04-30
Also published as: KR102604440B1; KR20200101815A; JP2020131984A; JP7199706B2

Abstract

Provided is a caster structure capable of orienting the direction of a caster in a specific direction even when a moving body having the caster is lifted as a whole or moved on a running surface having irregularities. A caster structure (1) is provided with: a turning shaft (33) rotatable about a vertical axis with respect to the body (10) of the lap-winder; a horizontal axle (55) provided at a position separated from the turning shaft (33) in the horizontal direction; and a tire (20) attached to the axle (55), wherein when the main body (10) and the tire (20) are lifted integrally, the tire (20) is not moved up and down, and the connecting rod (8) is returned to a neutral position by using a rod (92) or a spring (94) provided between the support rod (21) and the connecting rod (8), so that the tire (20) is directed in a straight direction.

Description

Caster structure

Technical Field

The present invention relates to a caster structure having a turning function, and more particularly, to a caster structure capable of directing the direction of a caster to a specific direction even when a moving body including the caster is directly lifted.

Background

Generally, casters are mounted on the lower end portions of movable tractors, dollies, chairs, and the like. The caster is configured such that a tire that rotates about a horizontal axis is attached to a turning portion that turns about a vertical axis, and when moving, the caster can follow a turn in the traveling direction by moving the axle of the tire forward in the traveling direction and then positioning the axle of the tire rearward of the turning portion.

However, when a moving body having such casters is moved, the entire moving body may be lifted and moved.

However, in the case of the entire lifting moving body, the casters may still face in the lifting direction or in a free direction due to vibration or the like. Therefore, when the vehicle is next moved in a different direction by contacting the ground, the caster wheels facing in a direction different from the traveling direction may give a load to the turning portion and the like.

In contrast, patent document 1 proposes a structure in which a tire is oriented in a specific direction only when the tire is lifted from a ground surface or the like without lifting up such a moving body or the like.

The structure described in patent document 1 is a structure in which casters can be moved in contact with the floor when a conference office table is moved, and when the office table is moved, a top plate is rotated by 90 degrees from a use position, and accordingly, a support column provided inside a leg is lowered to move a tire so as to protrude below a fixed leg. When the office table is used in the set state, the top plate is rotated in a horizontal plane, the tire is moved upward of the fixed leg portion together with the pillar provided inside the leg, and the caster is directed in a specific direction along the guide surface provided above the tire.

[ Prior Art document ]

[ patent document ]

[ patent document 1 ] Japanese patent laid-open No. 2005-96713

[ problem to be solved by the utility model ]

However, the structure of patent document 1 has the following problems.

That is, in the structure disclosed in patent document 1, when the entire office table is lifted up to get over a step or the like while the tire is moving in contact with the floor, the caster may be directed in various directions. Therefore, when the caster is moved while being in contact with the floor surface, the caster is in a free state, and there is a problem that a burden is imposed on a turning shaft or the like of the caster which is directed in various directions.

In addition, when such a structure is used for a caster structure of a large tractor, for example, since it is necessary to lift and lower a heavy tire, not only the structure becomes large, but also sand and the like enter a lifting and lowering portion and are likely to cause a failure.

In addition, when such casters are mounted at a plurality of locations, for example, when the running surface has irregularities such as a farmland or a stone-paved ground, the tires are oriented in different directions due to the irregularities, and the running becomes unstable.

SUMMERY OF THE UTILITY MODEL

The present invention has been made in view of the above problems, and an object of the present invention is to provide a caster structure capable of orienting the direction of a caster in a specific direction even when a moving body having the caster is lifted as a whole or moved on a running surface having an uneven surface.

[ MEANS FOR solving PROBLEMS ] A method for solving the problems

In order to solve the above problem, the present invention provides a caster structure including: a turning shaft which can rotate around a vertical axis relative to the main body; a horizontal rotation shaft provided at a position separated from the turning shaft in the horizontal direction; and a tire mounted on the rotation shaft, wherein the caster structure is provided with a biasing unit that, when the main body and the tire are integrally lifted up, causes the direction of the tire to face a specific direction without moving the tire up and down.

With this configuration, even when the entire body of the movable body is lifted, the direction of the tire can be oriented in the characteristic direction, and therefore, even when the tire is moved in a different direction by coming into contact with the ground, the burden on the steering shaft and the like can be eliminated. Further, even when the vehicle travels on a traveling surface having irregularities, the direction of the caster can be biased to a certain extent in the characteristic direction to travel, and therefore, the traveling can be stabilized.

In such a utility model, the caster structure is provided with a link rod that is connected to the left and right tires and that matches the angles of the left and right tires, and the biasing means is provided on the link rod.

With this configuration, the left and right tire directions can be simultaneously oriented in a specific direction when the main body is lifted up by the single biasing unit provided in the connecting rod.

Further, the caster structure is provided with: a support rod for supporting the left and right tires; and a connecting rod provided at a position separated from the support rod and used for matching the angles of the left and right tires, wherein the force application unit comprises an elastic body which enables the position of the connecting rod in the left and right directions to return to a neutral position relative to the support rod.

With this configuration, the link mechanism can be configured by the support rod, the coupling rod, and the like, and the angle between the inner wheel and the outer wheel can be changed by the link mechanism during turning left and right, and when the main body is lifted, the right and left tires can be oriented in the straight direction by returning the link mechanism to the neutral state.

Further, the urging unit includes: a pair of left and right rotatable levers mounted between the support lever and the coupling lever; and an elastic body mounted between the left and right rods.

With this configuration, the left and right levers can be pulled toward each other by the elastic member, and the coupling lever can be returned to the neutral position to direct the left and right tires in the straight direction. In this case, by providing the elastic body between the right and left levers, the pulling force in the right and left directions can be made the same, and it is possible to eliminate the case where only one tire is strongly pulled.

The caster structure is provided with a restricting member that restricts the rotation so as not to rotate the left and right rods from the center to the other rod side.

With this configuration, the rotation of the left and right levers in the opposite directions from the neutral position can be prevented by the restriction member, and the coupling lever can be returned to the neutral position by the elastic member provided between the left and right levers, so that the tire can be aligned in the straight direction.

The caster structure is provided with an axle moving portion that moves the axle in the front-rear direction at the time of forward movement and backward movement of the vehicle body with the support rod as a boundary.

With this configuration, when the main body is lifted, the direction of the tire can be oriented in the characteristic direction without changing the position of the biasing means between the forward movement and the backward movement.

[ Utility model effect ] is provided

According to the utility model discloses, the truckle structure possesses: a turning shaft which is rotatable about a vertical axis with respect to a main body of the movable body; a horizontal rotation shaft provided at a position separated from the turning shaft in the horizontal direction; and a tire mounted on the rotation shaft, wherein the caster structure is provided with a biasing unit which does not vertically move the tire and directs the direction of the tire to a specific direction when the main body and the tire are integrally lifted, so that the load on the rotation shaft and the like can be eliminated when the caster structure is moved to a different direction by being brought into contact with the ground next. Further, even when the vehicle travels on a traveling surface having irregularities, the direction of the caster can be biased to a certain extent in the characteristic direction to travel, and therefore, the traveling can be stabilized.

Drawings

Fig. 1 is a diagram showing a caster structure according to an embodiment of the present invention.

Fig. 2 is an exploded perspective view of the caster according to this embodiment.

Fig. 3 is a diagram showing the states of the ratchet portion and the axle when the vehicle advances in this mode.

Fig. 4 is a diagram showing states of the ratchet portion and the axle at the time of reverse travel in this embodiment.

Fig. 5 is a diagram showing a left-turn state and a state of the urging unit in this embodiment.

Fig. 6 is a diagram showing a right turn state and a state of the urging unit in this embodiment.

Fig. 7 is a diagram showing the operation of the state in which the different contact portions are provided according to this embodiment.

[ Mark Specification ]

1 … caster structure

2 … Caster (20 tyre, 21 support rod)

3 … turning part (31 upper side bearing part, 32 lower side bearing part, 33 turning shaft, 34 external thread part)

4 … axle moving part (41 axle guide, 42 screw hole, 43 guide surface, 44 groove, 45 long hole)

5 … axle supporting member (51 guide plate, 52 pin, 53 bearing, 54 bolt, 55 axle)

6 … ratchet part (61 claw part, 62 front end part, 63 fulcrum, 64 lower surface)

7 … rotating plate (71 projection)

8 … connecting rod (81 hinge, 82 protruding part)

9 … forcing unit (91 rotation axis, 92 rod, 93 contact part, 94 spring, 95 stopper)

10 … vehicle body

Detailed Description

Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

The moving body having the caster structure 1 of the embodiment is described by taking, as an example, a lap winder connected to the rear part of a tractor.

As shown in fig. 1, the caster structure 1 of this embodiment has casters 2 on the left and right sides of a main body 10, and moves a tire 20 to the rear of a turning shaft 33 using traction force from a front tractor when advancing, and moves the tire 20 to the front side so as to follow the turning shaft 33 without reversing the tire 20 by 180 degrees around a vertical axis when retreating. Further, characteristically, the left and right tires 20 are connected to each other by the support rod 21 and the connecting rod 8 so as to constitute a link mechanism, the direction of the tire 20 is oriented in the turning direction, and when the body 10 is lifted up as a whole by the tractor, the tire 20 is oriented in the straight direction by returning the connecting rod 8 to the neutral position by the biasing means 9 provided between the support rod 21 and the connecting rod 8.

First, as shown in fig. 2, the left and right casters 2 include a turning portion 3 having a turning shaft 33 that turns about a vertical axis, an axle moving portion 4 that moves the axle 55 in the front-rear direction with respect to the support rod 21 with respect to the turning shaft 33, and the like. By using such an axle moving unit 4, the tire 20 follows the turning shaft 33 without reversing the tire 20 by 180 degrees around the vertical axis.

The turning portions 3 of the caster 2 are provided at both ends of the support rod 21 attached to the main body 10, and a shaft insertion hole 35 is provided at the center of the upper bearing 31 or the lower bearing 32 which are vertically opposed to each other, and a turning shaft 33 is inserted therein with a certain gap from the vertical direction. A male screw portion 34 is formed at the tip end portion of the turning shaft 33 inserted into the shaft insertion hole 35, and is inserted and fixed into an upper and lower screw hole 42 provided at the center of an axle guide 41 constituting the axle moving portion 4. By inserting and fixing the turning shaft 33 into the screw hole 42 of the axle guide 41 in this manner, the axle moving portion 4 is rotated about the vertical axis about the center of the turning shaft 33 inserted into the shaft insertion hole 35.

On the other hand, the axle moving unit 4 attached to the turning unit 3 is configured to move the axle 55 in the front-rear direction of the turning shaft 33 using the rotational force of the tire 20, and includes an axle guide 41, an axle bearing member 5, a ratchet unit 6, and the like, wherein the axle guide 41 has a guide surface 43 parallel to the side surface of the tire 20, the axle bearing member 5 is slidable in the front-rear direction along the axle guide 41, and the ratchet unit 6 moves the axle 55 of the axle bearing member 5 in the front-rear direction along with the rotational force of the tire 20.

The axle guide 41 is provided with a guide surface 43 parallel to the side surface of the tire 20 and a groove 44 parallel to the upper and lower surfaces of the guide surface 43. The guide plate 51 of the axle bearing member 5 is slid in the front-rear direction along the groove 44 and the guide surface 43.

Pins 52 protruding in the vertical direction are provided at both front and rear ends of the guide plate 51 so as to be able to smoothly move along the groove 44 of the axle guide 41, and a bearing 53 or the like is attached to the front end of the pin 52, thereby reducing friction inside the groove 44.

Further, the guide surface 43 is provided with a long hole 45 along the front-rear direction. The elongated hole 45 is configured to allow the axle guide 41 to slide in the front-rear direction by a distance when the axle 55 is moved in the front-rear direction with respect to the turning shaft 33, and the bolt 54 is attached to the back surface side of the guide plate 51 and is brought into contact with the inside of the elongated hole 45. Accordingly, the axle 55 can move within the range of the elongated hole 45, and the axle 55 is positioned rearward of the turning shaft 33, whereby turning during forward movement is possible, and conversely, the axle 55 is positioned forward of the turning shaft 33, whereby turning during reverse movement is possible.

The ratchet portion 6 forcibly moves the axle 55 in the front-rear direction along the elongated hole 45, and the axle 55 is moved in the front-rear direction of the turning shaft 33 using the rotational force of the tire 20. As shown in fig. 2 to 4, the ratchet portion 6 is provided with a pair of front and rear rotatable claw portions 61 on the upper surface of the axle guide 41, the front end portions 62 (see fig. 3 and 4) of which face each other, and a rotary plate 7 having a projection which can come into contact with the front end portions 62 of the claw portions 61. The claw portions 61 move the respective tip end portions 62 up and down around a fulcrum 63 provided on the upper surface of the axle guide 41, and the rotating plate 7 rotates integrally with the tire 20. Then, the plurality of projections 71 are provided on a concentric circle on the surface of the rotating plate 7, and by moving the tire 20 forward, the rotating plate 7 is rotated in this direction as shown in fig. 3, and the projections 71 of the rotating plate 7 are brought into contact with the front end portions 62 of the claw portions 61 on the front side (fig. 3 upper view). At this time, since the protrusion 71 abuts against the front end 62 of the claw portion 61, the movement of the rotating plate 7 is restricted, and the axle 55 moves along the elongated hole 45 of the axle guide 41 so as to retreat rearward, as shown in the lower drawing of fig. 3. Thereby, the axle 55 moves rearward beyond the turning shaft 33. At this position, the protrusion 71 of the rotating plate 7 contacts so as to touch the lower surface 64 of the rear claw portion 61, and therefore the tire 20 can be continuously rotated. Conversely, when the main body 10 is retracted from this state, the tire 20 rotates in the reverse direction as shown in the upper view of fig. 4, and the rotating plate 7 also rotates in the same direction. Then, the projection 71 provided on the rotating plate 7 contacts the front end portion 62 of the rear pawl portion 61, and the axle 55 moves forward along the elongated hole 45 (fig. 4, bottom view) to release the rotational force. Then, in a state where the axle 55 is moved to the front side of the elongated hole 45, the protrusion 71 is brought into contact with the lower surface 64 of the front claw portion 61 by touching, and the rotation of the tire 20 is allowed only in front of the elongated hole 45. This allows the axle 55 to be positioned rearward of the turning shaft 33 during forward travel and allows the axle 55 to be positioned forward of the turning shaft 33 during reverse travel.

By moving the axle 55 forward and backward in this way, the tire 20 does not need to be inverted by 180 degrees about the vertical axis, and the directivity immediately after the backward movement can be stabilized, but when the ground has irregularities, the left and right casters 2 may be directed in different directions. Therefore, as shown in fig. 1, the left and right axle moving portions 4 are coupled to each other via the hinge 81 by the coupling rod 8, whereby the directions of the tires 20 of the left and right caster wheels 2 can be aligned.

As shown in fig. 1, the connecting rod 8 is attached to the left and right axle guides 41 via hinges 81. At this time, the connecting rod 8 is provided in parallel to the front side of the support rod 21 in advance, and the link mechanism is configured by the left and right turning shafts 33 and the left and right hinges 81. The distance between the left and right hinges 81 is shorter than the distance between the left and right turning shafts 33, and thus the trapezoidal links are formed by the left and right turning shafts 33 and the hinges 81.

In this configuration, in the present embodiment, the biasing means 9 is provided, and the biasing means 9 is used to direct the left and right tires 20 in the straight direction when the body 10 is moved to be raised using the tractor.

The biasing means 9 may be any method as long as it is a method of orienting the tire 20 in the straight direction when the body 10 is lifted up, but in this embodiment, as shown in fig. 5 and the like, a pair of right and left levers 92 are provided rotatably at the center of the support lever 21, a projection 82 is provided at the center of the coupling lever 8, and the abutment portion 93 of the lever 92 abuts against the projection 82. The rod 92 is mounted to be rotatable about a vertical axis with respect to a rotation shaft 91 provided on the support rod 21, and springs 94 such as the right and left rods 92 are attached to the tip end portions thereof and are pulled toward each other. Further, since the stopper 95 that prevents the left and right levers 92 from rotating in the opposite directions is provided on the support lever 21, when the projection 82 moves in either of the left and right directions (the state of fig. 5 or 6), the lever 92 on one side is brought into contact with the stopper 95 and the lever 92 on the opposite side is pulled by the spring 94. In the case where the protrusion 82 is returned to the neutral position by the spring 94 as described above, the left and right tires 20 are oriented in the straight direction, but in a situation where the tires 20 contact the ground, the frictional force generated by the contact of the tires 20 with the ground is greater than the spring force of the spring 94, and therefore the direction of the tires 20 during running is not affected.

Further, the contact portion 93 of the lever 92 that contacts the protrusion 82 has a curved shape that protrudes toward the protrusion 82. Thus, even when the lever 92 is rotated, the force from the lever 92 by the spring 94 can be directed in the direction along the connecting rod 8. That is, when the lever 92 is linearly formed, as shown in the right view of fig. 7, when the projection 82 moves in one direction, the force from the lever 92 acts in a direction perpendicular to the inclination angle of the lever 92, and the return force cannot be directed in the direction of the coupling rod 8. Therefore, here, by bending the contact portion 93 in an arc shape, as shown in the left side view of fig. 7, the return force generated by the spring 94 is directed in the direction of the connecting rod 8.

Next, the operation of the caster structure 1 configured as described above when the main body 10 is used will be described.

First, when the body 10 is moved forward by the tractor, the tire 20 rotates in a direction pulled by the tractor. Then, as shown in the upper view of fig. 3, the rotating plate 7 rotates with the rotation of the tire 20, and the projection 71 provided on the surface thereof abuts against the front end 62 of the front claw portion 61. Then, the axle 55 is moved backward to retract the rotary plate 7. Accordingly, the axle 55 is positioned rearward of the turning shaft 33 (lower view in fig. 3), and the tire 20 can follow in the traction direction when the vehicle is moving forward.

At this time, if the main body 10 is going to turn in the direction shown in fig. 5, the tire 20 turns around the turning shaft 33 following the traction direction. At this time, since the trapezoidal link is formed by the turning shaft 33 of the support lever 21 or the hinge 81 of the connecting lever 8, the angle of the tire 20 on the inner side in the turning direction can be increased, and the angle of the tire 20 on the outer side in the turning direction can be decreased. This can focus the axis of the tire 20 on the turning center side, and can prevent the generation of a thrust load.

On the other hand, when the direction is switched from the forward direction to the backward direction, the main body 10 is moved backward by the tractor. Then, the tire 20 rotates in the backward direction, and the rotating plate 7 also rotates in the backward direction in accordance with the rotation. Then, as shown in fig. 4, the projection 71 of the rotating plate 7 contacts the front end portion 62 of the rear claw portion 61, and the rotating plate 7 is retracted therefrom and moved forward. Then, the tire 20 is rotated with the axle 55 positioned in front of the turning shaft 33. Accordingly, by changing the front-rear direction of the axle 55 relative to the steering shaft 33, the directional stability when changing to the forward/backward direction and the running stability when running on a ground having irregularities can be ensured.

When the main body 10 is turned while moving backward in this way, the angle of the tire 20 on the inner side in the turning direction is increased and the angle of the tire 20 on the outer side in the turning direction is decreased by using the trapezoidal link in the same manner. Thus, the axial center of the tire 20 is focused on the turning center side, and therefore, generation of a thrust load can be prevented.

When such a main body 10 is lifted and moved by using a tractor, the main body 10 is lifted as it is by operating a lower link of the tractor.

Then, the tire 20 separates from the running surface, and the frictional force from the ground surface acting on the tire 20 disappears.

At this time, as shown in fig. 5, when the tire 20 turns in the left direction, the pin 82 of the connecting rod 8 moves in the right direction, and therefore the contact portion 93 of the right lever 92 is pressed by the projection 82. On the other hand, the left lever 92 is in contact with the stopper 95 and is in a neutral state, and the right lever 92 is pulled by the spring 94. Then, the link 8 is returned to the neutral position. At this time, since the contact portion 93 of the right lever 92 has a curved shape, the return force of the lever 92 is directed in the axial direction of the coupling rod 8, and the coupling rod 8 can be returned to the neutral position with a light force.

On the other hand, as shown in fig. 6, when the tire 20 is going to turn in the right direction, the pin 82 of the connecting rod 8 moves in the left direction, and therefore the contact portion 93 of the left lever 92 is pressed by the projection 82. On the other hand, the right-side lever 92 is in contact with the stopper 95 and is in a neutral state, and the left-side lever 92 is pulled by the spring 94. Then, the link 8 is returned to the neutral position. At this time, since the contact portion 93 of the left lever 92 has a curved shape, the returning force of the lever 92 is directed in the axial direction of the coupling rod 8, and the coupling rod 8 can be returned to the neutral position with a light force.

When the lever 92 is returned to the neutral position, the left and right tires 20 connected to the connecting rod 8 are directed in the straight direction.

As described above, according to the above embodiment, the caster structure 1 includes the turning shaft 33 rotatable about the vertical axis with respect to the main body 10 of the lap winder, the horizontal axle 55 provided at a position separated from the turning shaft 33 in the horizontal direction, and the tire 20 attached to the axle 55, and the caster structure 1 is provided with the urging means 9, and the urging means 9 does not move the tire 20 up and down and makes the direction of the tire 20 face the straight direction when the main body 10 and the tire 20 are lifted up integrally, so that it is possible to eliminate the burden on the turning shaft 33 and the like when the main body 10 and the tire 20 are moved in different directions by being brought into contact with the ground. Further, even when the vehicle travels on a traveling surface having irregularities such as a farm land, the vehicle can travel with the caster 2 directed to the straight direction to some extent, and thus the traveling can be stabilized.

The present invention is not limited to the above embodiments, and can be implemented in various forms.

For example, although the above embodiment has been described with an example of an agricultural machine such as a lap winder as an example of the moving body, the present invention can be applied to a configuration in which the moving body can move on a traveling surface such as a carriage, a desk, or a table.

In the above-described embodiment, as the caster structure 1, the position of the axle 55 that advances and retreats is changed by moving the axle 55 of the tire 20 in the front-rear direction with respect to the support rod 21, but the caster structure is not limited to this, and may be applied to a structure in which the tire 20 is turned 180 degrees about the vertical axis with respect to the turning shaft 33. However, when the present invention is applied to such a caster 2, if the connecting rod 8 is provided, the tire 20 cannot be turned 180 degrees. Therefore, the tire 20 may be directed in the straight direction by attaching a spring or the like for always directing the turning shaft 33 in the straight direction without providing the connecting rod 8.

Claims

1. A caster structure is provided with:

a turning shaft which can rotate around a vertical axis relative to the main body;

a horizontal rotation shaft provided at a position separated from the turning shaft in the horizontal direction; and

a tire mounted on the rotating shaft,

the caster wheel structure is characterized in that,

the caster structure is provided with a biasing unit that, when the main body and the tire are integrally lifted up, causes the direction of the tire to be directed in a specific direction without moving the tire up and down.

2. The caster structure as defined in claim 1,

the caster structure is provided with a connecting rod which is connected with left and right tires and enables the angles of the left and right tires to be consistent, and the force application unit is arranged on the connecting rod.

3. The caster structure as defined in claim 1,

the caster structure is provided with:

a support rod for supporting the left and right tires; and

a connecting rod which is arranged at a position separated from the supporting rod and enables the angles of the left and right tires to be consistent,

the biasing unit includes an elastic body that returns a position of the coupling rod in the left-right direction to a neutral position with respect to the support rod.

4. The caster structure as defined in claim 3,

the force application unit includes: a pair of left and right rotatable levers mounted between the support lever and the coupling lever; and an elastic body mounted between the left and right rods.

5. The caster structure of claim 4,

the caster structure is provided with a restricting member that restricts the rotation so as not to rotate the left and right rods from the center toward the other rod side.

6. The caster structure as defined in claim 1,

the caster structure is provided with an axle moving portion that moves an axle in the front-rear direction at the time of forward movement and backward movement of the vehicle body with the support rod as a boundary.