JP2021031041A - Caster and transport dolly - Google Patents

Abstract

To improve strength of a caster.SOLUTION: In casters 31A, 31B of the invention, a fixing part 50 has: a bolt member 51 which is inserted into a support part 36 and a swing part 42 and arranged along a swing axis O; a nut member 53 which is threadedly engaged with the bolt member 51; and a lower washer member 70 into which the bolt member 51 is inserted and which is located between the swing part 42 and the nut member 53 and provided with projection parts 71b projecting to the side of the swing part 42.SELECTED DRAWING: Figure 6

Description

The present invention relates to casters and transport trolleys.

As a transport trolley for transporting articles, Patent Document 1 discloses a transport trolley in which casters are attached to the lower surface of the trolley body via a mounting plate. The caster has a yoke that rotatably supports the wheels, and the upper and lower bowls are overlapped with bearings on the top and bottom of the top plate of the yoke. The casters are connected to the mounting plate by inserting the revolving shaft in the order of the mounting plate, the upper bowl, the top plate, and the lower bowl and caulking and fixing them.

Japanese Unexamined Patent Publication No. 2011-183938

In a transport trolley, a force may be applied to the casters due to an obstacle colliding with the wheels of the casters. In this case, there is a risk that the caster will be damaged due to the application of a force for pushing the lower bowl downward from the yoke.
The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to improve the strength of casters.

The present invention includes a wheel, a support portion that rotatably supports the wheel, a swivel portion that rotatably holds the support portion around the axis of the swivel shaft, and a fixing portion that fixes the swivel portion to a predetermined member. In the caster having the above, the fixing portion includes a bolt member along the swivel shaft through which the support portion and the swivel portion are inserted, a nut member screwed into the bolt member, and the bolt member. It is characterized by having a washer member that is inserted and is located between the swivel portion and the nut member and is provided with a protrusion that protrudes toward the swivel portion.

According to the present invention, the strength of the casters can be improved.

It is a bottom view of a transport trolley. It is a top view of a transport trolley. It is a side view of a transport trolley. It is a partial cross-sectional view of a caster. It is an exploded perspective view of a caster. It is a partially disassembled sectional view of a caster. It is sectional drawing which shows the state which a part of the caster is fixed to a mounting member. It is a figure which shows the structure of the lower washer member.

The casters and the transport trolley according to the present embodiment will be described with reference to the drawings.
FIG. 1 is a bottom view of the transport trolley 10. FIG. 2 is a plan view of the transport trolley 10. FIG. 3 is a side view of the transport trolley 10. In each figure, the traveling direction of the transport trolley 10 is the front-rear direction, and the front side is indicated by Fr, the rear side is indicated by Rr, the right side is indicated by R, and the left side is indicated by L. Therefore, the side view of FIG. 3 is a view seen from a direction orthogonal to the traveling direction of the transport carriage 10. The transport trolley 10 of the present embodiment is not limited to the front side, and can travel in any direction including front, rear, left and right.

The transport trolley 10 includes a trolley main body portion 20 and a traveling portion 30.
First, the carriage main body 20 will be described.
The bogie body 20 is formed by connecting a plurality of frame portions and the like, is longer in the front-rear direction than in the left-right direction in a plan view, and has a rectangular shape composed of a pair of long sides and a pair of short sides. As shown in FIGS. 1 and 2, the bogie body portion 20 includes a front frame portion 21a, a rear frame portion 21b, a right frame portion 21c, a left frame portion 21d, a corner member 22, and a reinforcing frame portion (reinforcing portion) 25a. It has 25b, 25c, a mounting plate 29, and the like.

For the front frame portion 21a, the rear frame portion 21b, the right frame portion 21c, and the left frame portion 21d, for example, a square hollow pipe made of an aluminum alloy or the like can be used. Further, the corner member 22 is made of an aluminum alloy formed by, for example, extrusion molding. The corner member 22 has an insertion hole 23 that opens upward and a stopper portion 24 that closes the lower part. The hand push member 80 can be inserted into the insertion hole 23 of the corner member 22. The lower end of the hand pushing member 80 inserted into the insertion hole 23 is supported by the stopper portion 24. As the push member 80, for example, a straight pipe made of iron or an aluminum alloy and having a circular cross section, that is, a so-called single pipe can be applied.

The front frame portion 21a, the rear frame portion 21b, the right frame portion 21c, and the left frame portion 21d are joined by the corner member 22 at four corners to form a rectangular four-sided frame. Frame Inside the frame, a plurality of reinforcing frame portions 25a, 25b, 25c are attached to each other in the front-rear and left-right directions, and are reinforced by being joined by screws, rivets, welding, or the like. For the reinforcing frame portions 25a, 25b, 25c, for example, a square hollow pipe made of an aluminum alloy, a plate having an uneven cross section, or the like can be used. Here, by joining 12 reinforcing frame portions 25c that are short in the left-right direction to two reinforcing frame portions 25a and 25b that are long in the front-rear direction, three rows are formed in the front-rear direction when viewed in a plan view. A plurality of rectangular spaces 26 divided into five rows in the left-right direction are formed.

Further, the dolly main body 20 has mounting members 27A and 27B as predetermined members. The mounting members 27A and 27B mount casters 31A and 31B on the lower surface of the dolly body 20. Specifically, the mounting member 27A uses rivets 28 and screws in each frame portion and each reinforcing frame portion so as to block the space 26 on both the front side and the left and right directions and the space 26 on the rear side and both the left and right sides from the lower side. Is combined. The mounting member 27A is, for example, a metal plate made of an aluminum alloy with rectangular corners cut out. On the other hand, the mounting member 27B is connected to each frame portion and each reinforcing frame portion via rivets or screws so as to close the space 26 in the center in the front-rear direction and on both sides in the left-right direction from below. The mounting member 27B is, for example, a metal plate made of, for example, an aluminum alloy, in which adjacent rectangular corners are cut out.
The mounting plate 29 is mounted on the upper part of the space 26 that is not blocked by the mounting members 27A and 27B among the plurality of spaces 26. The mounting plate 29 is a flat plate for loading a transported object. The mounting plate 29 is connected to each frame portion and each reinforcing frame portion via rivets 28 and screws.

The traveling unit 30 travels on the traveling surface while supporting the load of the bogie main body 20 and the transported object. The traveling unit 30 has a plurality of casters 31A and 31B. As shown in FIG. 1, the traveling portion 30 includes four casters 31A arranged at the four corners of the bogie main body portion 20 and two casters 31B located at the center in the front-rear direction and arranged apart from each other on the left and right. Has one caster. The casters 31A are attached to the carriage body 20 via the attachment member 27A. Since the casters 31A are arranged at the four corners of the lower surface of the trolley main body 20, the transport trolley 10 can be run in a stable state. Further, the casters 31B are attached to the carriage main body 20 via the attachment member 27B. Since the casters 31B are arranged apart from each other on the left and right at the center of the trolley main body 20 in the front-rear direction, the transport trolley 10 can travel without tilting even if the transported objects are unevenly loaded on the mounting plate 29.

The casters 31A and 31B can swivel around the swivel shaft O, which is a vertical shaft. Further, the caster 31A is a caster with a brake that can apply the brake and release the brake according to the operation of the user. On the other hand, the caster 31B arranged in the center is a caster without a brake.

Here, the caster 31A will be described with reference to FIGS. 4 to 6. FIG. 4 is a partial cross-sectional view of the caster 31A. FIG. 5 is an exploded perspective view of the caster 31A. FIG. 6 is a partially exploded cross-sectional view of the caster 31A.
The caster 31A of the present embodiment has a wheel 32, a support portion 36, a swivel portion 42, a fixing portion 50, and the like.
The wheel 32 has a wheel portion 32a having a bearing built therein, and a tire portion 32b fitted on the outer periphery of the wheel portion 32a.

The support portion 36 rotatably supports the wheels 32 via the axle 35. The support portion 36 has a fork member 37 that supports the wheel 32 and a pedal holding member 38 that swingably supports the brake pedal 40.
The fork member 37 is formed, for example, by press-molding a steel plate. The fork member 37 is integrally formed of a pair of side walls 37a located on both sides of the wheel 32 and a circular top plate 37b in which the pair of side walls 37a are connected on the upper side of the wheel 32. An axle 35 is inserted through the pair of side walls 37a. The top plate 37b is rotatably held by the swivel portion 42. An insertion hole 37c is formed in the center of the top plate 37b coaxially with the swivel shaft O of the caster 31A. Further, the top plate 37b is formed with an annular accommodating groove 37d centered on the swivel shaft O so that the bearing 45 can be stably arranged on the upper surface and the bearing 46 can be stably arranged on the lower surface.

The pedal holding member 38 is formed, for example, by press-molding a steel plate. The pedal holding member 38 is integrally formed of a pair of side walls 38a located on both sides of the wheel 32 and a connecting plate 38b connecting the pair of side walls 38a on the upper side. The pair of side walls 38a are formed so as to extend from the connecting plate 38b in a bifurcated manner in different directions. One side of the bifurcated shape communicates with the fork member 37 and the axle 35 is inserted, and the other side of the bifurcated shape is connected to the pair of side walls 37a of the fork member 37. Further, the pair of side walls 38a swingably support the brake pedal 40 by the swing shaft 39 at a position close to the connecting plate 38b. In the state where the pedal holding member 38 is connected by the fork member 37, the connecting plate 38b inclines downward toward the rear part.

The brake pedal 40 is formed, for example, by press-molding a steel plate. The brake pedal 40 has a pedal body 40a and an operation piece 40b as an operation unit that integrally extends from the pedal body 40a. The pedal body 40a is integrally formed of a pair of side walls 40c located on both sides of the wheel 32 and a connecting plate 40d in which the pair of side walls 40c are connected at the top. The brake pedal 40 can be positioned in the pedal holding member 38 so that the connecting plate 40d overlaps the connecting plate 38b of the pedal holding member 38. The brake pedal 40 can swing up and down with respect to the pedal holding member 38 about the swing shaft 39. The operation piece 40b has a substantially plate shape, and the vertical swing of the brake pedal 40 is operated by a user's foot or the like. The operation piece 40b is formed so as to extend diagonally from the rear portion of the connecting plate 40d of the pedal body 40a. A cover portion 41 is attached to the operation piece 40b. The cover portion 41 is made of synthetic resin and is colored so that the user can recognize it at a glance. Specifically, the cover portion 41 is colored in a color different from that of the brake pedal 40, that is, a color different from that of the pedal body 40a and the operation piece 40b.

In order to apply the brake on the caster 31A, the user operates the operation piece 40b of the brake pedal 40 by stepping on the lower side with his / her foot. The brake pedal 40 swings downward with the swing shaft 39 as the center against the urging of an urging member (not shown), so that the brake pedal 40 directly or indirectly moves the outer peripheral surface of the wheel 32. The brake is applied in order to press the wheel firmly (see the brake pedal 40 shown by the alternate long and short dash line in FIG. 4). In addition, the brake pedal 40 maintains the braked state, so that it functions as a stopper.

The swivel portion 42 holds the support portion 36 (specifically, the top plate 37b of the fork member 37) so as to be swivel around the axis of the swivel shaft O. The swivel portion 42 has an upper member 43, a lower member 44, a bearing 45, a bearing 46, and a coupling member 47.
The upper member 43 is formed in a substantially dish shape, for example, by press-molding a steel plate. The upper member 43 is arranged above the top plate 37b. The upper member 43 is formed in a circular shape larger than the top plate 37b, and an insertion hole 43a is formed in the center coaxially with the swivel shaft O. A coupling member 47 is inserted into the insertion hole 43a. Further, the upper member 43 is formed with an annular accommodating groove 43b in order to stably arrange the bearing 45 on the lower surface. By forming the annular accommodating groove 43b on the lower surface in this way, conversely, an arcuate projecting portion 43c is formed on the upper surface of the upper member 43 along the annular shape centered on the swivel axis O in a cross-sectional view. To.

The lower member 44 is formed in a substantially dish shape, for example, by press-molding a steel plate. The lower member 44 is arranged below the top plate 37b. The lower member 44 is formed in a circular shape smaller than the top plate 37b, and an insertion hole 44a is formed in the center coaxially with the swivel shaft O. A coupling member 47 is inserted into the insertion hole 44a. The inner diameter of the insertion hole 44a of the lower member 44 is substantially the same as the inner diameter of the insertion hole 43a of the upper member 43. Further, the lower member 44 is formed with an annular accommodating groove 44b in order to stably arrange the bearing 46 on the upper surface. By forming the annular accommodating groove 44b on the upper surface in this way, conversely, the lower surface of the lower member 44 faces the radial direction from the swivel shaft O in a cross-sectional view along the ring centered on the swivel shaft O. As a result, an inclined portion 44c that inclines downward is formed. In FIG. 6, the inclination angle of the inclined portion 44c is indicated by α. The inclination angle α is an angle at which the lower surface of the inclined portion 44c is inclined with respect to the horizontal plane and is an acute angle side angle.
The bearing 45 is arranged between the accommodating groove 43b of the upper member 43 and the accommodating groove 37d of the top plate 37b.
The bearing 46 is arranged between the top plate 37b and the accommodating groove 44b of the lower member 44.

The connecting member 47 is formed in a substantially tubular shape. The coupling member 47 is provided with the upper member 43 so that the upper member 43 and the lower member 44 arranged vertically with the top plate 37b of the fork member 37 sandwiched between the upper member 43 and the lower member 44 do not relatively rotate around the axis of the swivel shaft O. It is connected to the lower member 44.
An insertion hole 47a is formed in the center of the coupling member 47 coaxially with the swivel shaft O. Further, the coupling member 47 has an upper flange portion 47b at the upper end.

The connecting member 47 shown by the solid line in FIG. 6 shows a state before connecting the upper member 43 and the lower member 44. After inserting the coupling member 47 before coupling into the insertion hole 43a of the upper member 43 and the insertion hole 44a of the lower member 44, the lower end is crimped and deformed as in the coupling member 47 shown by the alternate long and short dash line in FIG. The lower flange portion 47c is formed by allowing the lower flange portion 47c to be formed. The lower flange portion 47c vertically overlaps with the lower member 44 at a portion close to the insertion hole 44a of the lower member 44.
The upper flange portion 47b and the lower flange portion 47c are annular, and their outer diameters are larger than the inner diameter of the insertion hole 43a of the upper member 43 and the inner diameter of the insertion hole 44a of the lower member 44, respectively. The connecting member 47 connects the upper member 43 and the lower member 44 by sandwiching the portion close to the insertion hole 43a and the portion close to the insertion hole 44a between the upper flange portion 47b and the lower flange portion 47c from above and below.

In this way, the upper member 43 and the lower member 44 are integrally connected by the coupling member 47 so as not to rotate relatively, so that the top plate 37b of the fork member 37 becomes the upper member 43 and the lower member 44. On the other hand, the swivel shaft O can be swiveled through the bearings 45 and 46.
Here, the coupling member 47 can be more difficult to disengage from the upper member 43 and the lower member 44 as the outer diameter of the lower flange portion 47c is larger, but the lower end of the coupling member 47 is deformed to form the lower flange portion 47c. It is not possible to secure a sufficient outer diameter for this purpose. In the coupling member 47 of the present embodiment, the outer diameter of the lower flange portion 47c is smaller than the outer diameter of the upper flange portion 47b, and a gap is formed on the outside of the outer peripheral edge of the lower flange portion 47c. Specifically, a gap S is formed between the outer edge of the lower flange portion 47c of the coupling member 47 shown by the alternate long and short dash line in FIG. 6 and the inclined portion 44c of the lower member 44.

The fixing portion 50 fixes the swivel portion 42 to the mounting member 27A on which the reinforcing member 60 is superposed on the lower side. Here, first, the mounting member 27A will be described.
The mounting member 27A is formed, for example, by press-molding a plate-shaped aluminum alloy. An insertion hole 27a is formed in the mounting member 27A coaxially with the swivel shaft O at substantially the center. The insertion hole 27a is formed at a position where the head portion 51a is stepped down from the upper surface 27b in a conical shape so that the head portion 51a does not protrude upward from the upper surface (surface) 27b of the mounting member 27A when the bolt member 51 described later is inserted. .. An annular rib 27c centered on the swivel shaft O is formed on the mounting member 27A. The annular rib 27c bulges from the lower surface of the mounting member 27A. Further, a plurality of rectangular ribs 27d are formed on the mounting member 27A so as to surround the annular ribs 27c. The rectangular rib 27d is formed by denting from the lower surface along the outer shape of the rectangle. That is, the region in the rectangular rib 27d is a flat surface flush with the lower surface of the mounting member 27A. By forming the annular rib 27c and the rectangular rib 27d, the rigidity of the mounting member 27A can be improved.
A plurality of fixing holes 27e for inserting the rivet 28 and attaching the attachment member 27A to the bogie body 20 are formed around the attachment member 27A.

The reinforcing member 60 is formed, for example, by press-molding a plate-shaped aluminum alloy. The reinforcing member 60 is arranged between the upper member 43 of the caster 31A and the mounting member 27A when the swivel portion 42 of the caster 31A is fixed to the mounting member 27A. At this time, the reinforcing member 60 comes into contact with both the upper portion of the upper member 43 of the swivel portion 42 and the lower portion of the mounting member 27A. The reinforcing member 60 is formed with a circular opening 60a centered on the swivel shaft O. The inner diameter of the opening 60a is smaller than the outer diameter of the upper member 43 and larger than the diameter of the annular protrusion 43c of the upper member 43.

Further, the reinforcing member 60 is formed with a lower convex portion 60b that contacts the upper surface of the upper member 43 and an upper convex portion 60c that contacts the lower surface of the mounting member 27A. The lower convex portion 60b has a rib-like shape that bulges downward, and is formed at equidistant positions along the circumferential direction about the swivel axis O. Further, the upper convex portion 60c has a rib-like shape that bulges upward relative to the lower convex portion 60b, and is formed at equidistant positions along the circumferential direction with the swivel axis O as the center. .. Therefore, when the reinforcing member 60 is viewed in a plan view, the lower convex portion 60b and the upper convex portion 60c are alternately formed along the annular shape.
Each upper convex portion 60c is formed with a concave portion 60d along an annular shape in the center thereof. The recess 60d is for avoiding interference with the annular rib 27c in order to bring the upper convex portion 60c of the reinforcing member 60 and the lower surface of the mounting member 27A into contact with each other on a flat surface.

By overlapping the mounting member 27A and the reinforcing member 60, the outer peripheral side of the upper surface of each upper convex portion 60c with respect to the concave portion 60d is brought into contact with the rectangular rib 27d of the mounting member 27A, respectively. Here, since the inside of the rectangular rib 27d of the mounting member 27A is a flat surface, the reinforcing member 60 and the mounting member 27A overlap each other without rattling.

The fixing portion 50 includes a bolt member 51, an upper washer member 52, a nut member 53, and a lower washer member 70.
The bolt member 51 has a head portion 51a and a male screw portion 51b.
The upper washer member 52 is formed, for example, by press-molding a plate-shaped aluminum alloy. The upper washer member 52 is arranged between the head portion 51a of the bolt member 51 and the mounting member 27A. The upper washer member 52 is formed with an insertion hole 52a in which the bolt member 51 is inserted coaxially with the swivel shaft O. The insertion hole 52a is formed at a position where the head portion 51a of the bolt member 51 is stepped down in a conical shape so as not to protrude upward from the upper surface 27b of the mounting member 27A when the bolt member 51 is inserted.
The nut member 53 has a flange portion 53a and a female screw portion 53b. The female screw portion 53b is screwed into the male screw portion 51b of the bolt member 51.

The lower washer member 70 corresponds to an example of a washer member. The lower washer member 70 is formed by, for example, press-forming a plate-shaped aluminum alloy, a steel plate, or the like.
FIG. 8 is a diagram showing an example of the configuration of the lower washer member 70. 8 (a) is a plan view of the lower washer member 70, and FIG. 8 (b) is a cross-sectional view of the line II shown in FIG. 8 (a) as viewed from the direction of the arrow.
The lower washer member 70 has a substantially truncated cone shape, and has a substantially disc-shaped main body portion 71 and an inclined portion 72.

The main body 71 has a substantially disk shape, and an insertion hole 71a coaxial with the swivel shaft O and through which the bolt member 51 is inserted is formed in the center. Further, the main body 71 is integrally provided with a protrusion 71b that projects upward from the upper surface. The protrusion 71b is arranged so as to surround the insertion hole 71a along the outer peripheral edge of the main body 71.
The main body 71 of the present embodiment is provided with a plurality of (for example, eight) protrusions 71b. The protrusions 71b are formed at equidistant positions along the circumferential direction about the swivel axis O. As shown in FIG. 8B, the vertical height H of each protrusion 71b is equal to or less than the vertical plate thickness t of the main body portion 71 and is 1 / 2t or more. The protrusion 71b is formed by press molding from the lower surface of the main body 71, and the main body 71 is formed with a recess 71c when press molding is performed at each position on the lower surface opposite to each protrusion 71b. ..

The inclined portion 72 is inclined downward from the outer circumference of the main body portion 71 toward the outside in the radial direction. In FIG. 8, the inclination angle of the inclined portion 72 is shown by β. The inclination angle β is an angle at which the upper surface of the inclined portion 72 is inclined with respect to the horizontal plane and is an acute angle side angle. In the present embodiment, the tilt angle β of the tilt portion 72 is substantially the same as the tilt angle α of the tilt portion 44c described above, or is equal to or less than the tilt angle α. However, if the inclination angle β of the inclined portion 72 is small, the inclined portion 44c and the inclined portion 72 do not come into contact with each other. Therefore, the inclination angle β of the inclined portion 72 is preferably an inclination angle of 1 / 2α or more. Further, the lower washer member 70 is formed with a space 73 surrounded by the main body portion 71 and the inclined portion 72.

Next, a case where the swivel portion 42 of the caster 31A is fixed to the mounting member 27A on which the reinforcing member 60 is superposed on the lower side by using the fixing portion 50 will be described with reference to FIG.
Here, it is assumed that the wheels 32, the support portion 36, and the swivel portion 42 of the casters 31A are already assembled. Therefore, the fork member 37 of the support portion 36 rotatably supports the wheel 32 via the axle 35, and the pedal holding member 38 of the support portion 36 rotatably supports the brake pedal 40. Further, the swivel portion 42 holds the support portion 36 so as to be swivel around the axis of the swivel shaft O. Therefore, the lower flange portion 47c is formed at the lower end as in the coupling member 47 shown by the alternate long and short dash line in FIG. 6, and the upper member 43 and the lower member 44 are joined by the upper flange portion 47b and the lower flange portion 47c from above and below. ing.

First, as shown in FIG. 6, the male screw portion 51b of the bolt member 51 is inserted from above along the swivel shaft O into the insertion hole 52a of the upper washer member 52, the insertion hole 27a of the mounting member 27A, and the insertion hole of the coupling member 47. 47a and the insertion hole 71a of the lower washer member 70 are inserted in this order. At this time, the reinforcing member 60 is superposed on the mounting member 27A on the lower side.
Next, the swivel portion 42 of the caster 31A can be fixed to the mounting member 27A by screwing the female screw portion 53b of the nut member 53 into the male screw portion 51b of the bolt member 51 in the fork member 37.

FIG. 7 is a diagram showing an example of a state in which the swivel portion 42 of the caster 31A is fixed to the mounting member 27A. As shown in FIG. 7, the lower washer member 70 is located between the swivel portion 42 and the nut member 53. Specifically, the upper surface of the main body 71 of the lower washer member 70 is in contact with the lower end of the coupling member 47, that is, the lower surface of the lower flange 47c. The main body 71 of the lower washer member 70 of the present embodiment has a protrusion 71b that projects upward from the upper surface, specifically toward the lower member 44 of the swivel portion 42.
Here, each protrusion 71b is located outside the outer peripheral edge of the lower end of the coupling member 47, that is, outside the outer edge of the lower flange portion 47c. Specifically, each protrusion 71b is located in the gap S between the outer edge of the lower flange portion 47c and the inclined portion 44c of the lower member 44. By locating each of the protrusions 71b in the gap S in this way, the lower member 44 and the lower washer member 70 can be brought close to each other in the vertical direction.
As shown in FIG. 7, in the present embodiment, the upper end of each protrusion 71b and the lower member 44 are separated by a distance L in the vertical direction, but the upper end of each protrusion 71b and the lower member 44 are separated from each other. May be in contact.

Further, the inclined portion 72 of the lower washer member 70 is in contact with the inclined portion 44c of the lower member 44. Specifically, the upper surface of the inclined portion 72 of the lower washer member 70 is in contact with the lower surface of the inclined portion 44c of the lower member 44. As described above, since the tilt angle β of the tilt portion 72 is substantially the same as the tilt angle α of the tilt portion 44c or equal to or less than the tilt angle α, the tilt portion 72 of the lower washer member 70 is the tilt portion of the lower member 44. It becomes easy to come into contact with 44c.
Further, the nut member 53 is in contact with the lower washer member 70. Specifically, the upper surface of the flange portion 53a of the nut member 53 is in contact with the lower surface of the main body portion 71 of the lower washer member 70. A part of the nut member 53 is located in the space 73 of the lower washer member 70.

Here, the caster 31A has been described, but the caster 31B has a configuration in which the members related to the brake are omitted from the caster 31A. Specifically, the caster 31B has a wheel 32, a support portion 36, a swivel portion 42, and a fixing portion 50, but the support portion 36 does not have the pedal holding member 38. Therefore, the caster 31B does not have the brake pedal 40 and cannot apply the brake. However, since the caster 31B has a configuration in which the swivel portion 42 rotatably holds the support portion 36 (specifically, the top plate 37b of the fork member 37) around the axis of the swivel shaft O, similarly to the caster 31A. , The fork member 37 can swivel around the swivel shaft O. Further, the mounting member 27B to which the swivel portion 42 of the caster 31B is fixed does not have the annular rib 27c formed on the mounting member 27A and the plurality of rectangular ribs 27d, and is substantially flat. Further, in the configuration in which the swivel portion 42 of the caster 31B is fixed to the mounting member 27B, the caster 31A is fixed to the mounting member 27A except that the reinforcing member 60 is not arranged between the upper member 43 of the caster 31B and the mounting member 27B. Similar to the configuration.

Next, the operation of the lower washer member 70 of the fixing portion 50 will be described.
Here, it is assumed that an obstacle collides with the wheel 32 of the caster 31A. When an obstacle collides with the wheel 32, a rotational moment is generated on the caster 31A, and a force is applied to push the lower member 44 downward from the top plate 37b of the fork member 37. As described above, since the lower flange portion 47c cannot secure a sufficient outer diameter, the lower member 44 is pushed down to apply a force locally to the lower flange portion 47c of the coupling member 47. , The coupling member 47 or the lower member 44 may be damaged.
Here, in the present embodiment, in a state where the swivel portion 42 of the caster 31A is fixed to the mounting member 27A, the lower washer member 70 moves from the upper surface of the main body 71 to the upper side, specifically, the swivel portion 42. It has a protrusion 71b that projects toward the lower member 44. The protrusion 71b is located in the gap S between the outer edge of the lower flange portion 47c and the inclined portion 44c of the lower member 44.

Therefore, when the lower member 44 is pushed down from the top plate 37b of the fork member 37, the protrusion 71b of the lower washer member 70 comes into contact with the lower surface of the lower member 44, so that the lower member 44 is lowered. It is possible to prevent it from being pushed down to the side. By preventing the lower member 44 from being pushed down in this way, the force applied from the lower member 44 to the lower flange portion 47c of the coupling member 47 can be dispersed to the lower washer member 70. Therefore, it is possible to prevent the coupling member 47 or the lower member 44 from being damaged.
By making sure that the upper end of the protrusion 71b and the lower washer member 70 are in contact with each other without being separated in the vertical direction, it is possible to further prevent the lower member 44 from being pushed down.

Further, in the present embodiment, the inclined portion 72 of the lower washer member 70 is in contact with the inclined portion 44c of the lower member 44 in a state where the swivel portion 42 of the caster 31A is fixed to the mounting member 27A. Therefore, the inclined portion 72 of the lower washer member 70 can prevent the lower member 44 from being pushed down.

As described above, according to the present embodiment, the bolt member 51 is inserted, and the protruding portion 71b located between the swivel portion 42 and the nut member 53 and projecting toward the swivel portion 42 is provided. It has a lower washer member 70. When an obstacle collides with the wheel 32, a force is applied from the support portion 36 to push down the turning portion 42 downward. At this time, the protrusion 71b of the lower washer member 70 is in contact with or in contact with the swivel portion 42, thereby preventing the swivel portion 42 from being pushed down. Therefore, the swivel portion 42 can be prevented from being damaged, and the strength of the caster 31A can be improved. Although the caster 31A has been described here, the strength of the caster 31B can be improved in the same manner.

Further, according to the present embodiment, the lower washer member 70 is provided with the protrusion 71b integrally with the main body 71, so that the number of parts can be reduced. Therefore, the work of fixing the swivel portion 42 of the caster 31A to the mounting member 27A by using the fixing portion 50 can be easily performed.
Further, according to the present embodiment, since the lower washer member 70 is provided with the protrusion 71b integrally with the main body 71, compared with the case where the main body 71 and the protrusion 71b are formed separately. It can be confirmed that the protrusion 71b is present only by visually recognizing the lower washer member 70 from the outside.

Although the present invention has been described above with the above-described embodiments, the present invention is not limited to the above-described embodiments, and changes can be made within the scope of the present invention.
In the above-described embodiment, the case where the predetermined members are the mounting members 27A and 27B has been described, but the present invention is not limited to this case. The predetermined member may be any member as long as it is a member on the dolly body 20 side.
Further, in the above-described embodiment, the case where the lower washer member 70 is provided with a plurality of protrusions 71b has been described, but the case is not limited to this case. The protrusion 71b of the lower washer member 70 may be an annular protrusion that continuously surrounds the insertion hole 71a along the outer peripheral edge of the main body 71.

Further, in the above-described embodiment, the case where the lower washer member 70 is provided with the protrusion 71b integrally with the main body 71 is described, but the present invention is not limited to this case, and the main body 71 and the protrusion 71b are separate bodies. There may be. In this case, the plurality of protrusions 71b are formed of an annular member such as a ring that continuously surrounds the insertion hole 71a along the outer peripheral edge of the main body 71. By arranging the annular member in the above-mentioned gap S so as to communicate with the insertion hole 71a of the main body portion 71, it is possible to prevent the swivel portion 42 from being damaged as in the above-described embodiment.

Further, in the above-described embodiment, the case where the traveling unit 30 has six casters 31A and 31B has been described, but the present invention is not limited to this case, and only four casters 31A may be used. Further, the two casters 31B of the traveling portion 30 may be provided apart from each other in the front-rear direction so as not to overlap the four casters 31A in the side view.
Further, in the above-described embodiment, the case where the fixing portion 50 has the upper washer member 52 has been described, but the case is not limited to this case, and the fixing portion 50 may not have the upper washer member 52.

10: Transport trolley 20: Cart body part 27A, 27B: Mounting plate 30: Traveling part 31A, 31B: Caster 32: Wheel 36: Support part 37b: Top plate 42: Swivel part 43: Upper member 44: Lower member 44c: Inclined part 47: Joining member 50: Fixing part 51: Bolt member 53: Nut member 70: Lower washer member (washer member) 71b: Protruding part 72: Inclined part

Claims (5)

With wheels
A support portion that rotatably supports the wheel and
A swivel part that holds the support part so that it can swivel around the axis of the swivel shaft,
A caster having a fixing portion for fixing the swivel portion to a predetermined member.
The fixed part is
A bolt member along the swivel shaft through which the support portion and the swivel portion are inserted,
A nut member screwed into the bolt member and
A caster characterized in that the bolt member is inserted and the washer member is located between the swivel portion and the nut member and is provided with a protrusion that protrudes toward the swivel portion. .. The swivel part
Upper and lower members arranged above and below the top plate of the support portion, and
The bolt member is inserted and has a connecting member for connecting the upper member and the lower member.
The washer member
The caster according to claim 1, wherein the caster is in contact with the connecting member. The connecting member is
The lower end overlaps the lower member vertically,
The protrusion is
The caster according to claim 2, wherein the caster is located outside the outer peripheral edge of the lower end of the connecting member and projects upward toward the lower surface of the lower member. The lower member
It has an inclined portion that inclines downward from the turning axis toward the outside in the radial direction.
The washer member
The caster according to claim 2 or 3, wherein the caster is in contact with the lower surface of the inclined portion. A transport carriage according to any one of claims 1 to 4, wherein the casters can be attached to the carriage main body via the predetermined member.

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