JP2009040377A - Carriage - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a carriage capable of securing stable travelling and improved in turnability. <P>SOLUTION: This carriage 1 comprises front wheel casters 7 provided on a front side in the progressing direction, rear wheel casters 8 provided on a rear side in the progressing direction, and fixed wheels 9 provided between the front wheel casters 7 and the rear wheel casters 8. The front wheel casters 7 and the rear wheel casters 8 are fitted to anteroposterior free ends 3a and 3b of a cantilever leaf spring 3 provided in the bottom part of a frame 2. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a transport vehicle.

Conventionally, as this type of transport vehicle, a pair of front wheel casters and a pair of rear wheel casters provided at the four corners of the bottom of the main body, and a pair of fixed wheels provided between the pair of front wheel casters and the pair of rear wheel casters Have been proposed.
In this transport vehicle, a front wheel caster and a fixed wheel are attached to a connecting member provided swingably on the bottom of the main body, and a rear wheel is attached to a connecting member provided swingably on the bottom of the main body. Further, the connecting member and the connecting member are provided. Are connected to each other so that they can swing, even if any of the front wheels, rear wheels and fixed wheels rides on the step or uneven surface of the running surface, the remaining two wheels are in contact with the running surface. Driving stability is assumed to be good.
Japanese Utility Model Publication No. 7-8148

  However, in such a transport vehicle, not only a connecting member and a fishing support plate and a fishing rod for swingingly supporting the connecting member on the bottom of the main body are required, but the structure is complicated. There is a problem such as.

  An object of the transport vehicle of the present invention is to easily ensure stable traveling. Moreover, the conveyance vehicle of this invention makes it one of the objectives to improve turning property. Furthermore, the conveyance vehicle of this invention makes it one of the objectives to ensure the stable steering property.

  In order to achieve at least a part of the above object, the transport vehicle of the present invention employs the following means.

  The transport vehicle of the present invention includes a front wheel caster provided on the front side in the traveling direction, a rear wheel caster provided on the rear side in the traveling direction, and a fixed wheel provided between the front wheel caster and the rear wheel caster. The gist of the invention is that the front wheel caster and the rear wheel caster are attached to a free end side of a leaf spring member installed in a cantilever manner on the bottom of the transport vehicle.

  In the transport vehicle of the present invention, the front wheel caster and the rear wheel caster are attached to the free end side of the leaf spring member installed in a cantilever manner on the bottom of the transport vehicle. The plate spring member can be bent and all the wheels can be kept in contact with the running surface even if the bumps are stepped on or uneven. Moreover, since the front wheel caster and the rear wheel caster are simply attached to the free end side of the leaf spring member, the structure is simple. As a result, stable running performance can be easily ensured.

  In the transport vehicle of the present invention, the leaf spring member may be a single leaf spring installed on the bottom so that the front side in the traveling direction and the rear side in the traveling direction are free ends. In this way, since only one leaf spring member is required, an increase in the number of parts can be suppressed.

  In the transport vehicle of this aspect of the present invention, the front wheel caster includes a left front wheel caster provided on the left side with respect to the traveling direction, and a right front wheel caster provided on the right side with respect to the traveling direction, The rear wheel caster includes a left rear wheel caster provided on the left side with respect to the traveling direction, and a right rear wheel caster provided on the right side with respect to the traveling direction, and the leaf spring member includes the left front wheel A left leaf spring to which a caster and the left rear wheel caster are attached and a right leaf spring to which the right front wheel caster and the right rear wheel caster are attached may be provided. In this way, since the left and right casters can be attached to separate leaf springs, all the wheels can be more reliably grounded to the running surface.

  Further, in the transport vehicle having a fixed wheel provided between the front wheel caster and the rear wheel caster at the bottom, the front wheel caster and / or the rear wheel caster has a ground contact surface in a state where the plate spring member is not bent. Further, it may be attached so as to be vertically above the ground contact surface of the fixed ring. If it carries out like this, in a flat ground, a front wheel caster and a rear wheel caster will ground to a running surface in the state where a leaf spring member was bent vertically downward. That is, since the front wheel casters and the rear wheel casters are grounded to the running surface in a state where they receive a vertical upward biasing force from the leaf springs 3 and 4, the front wheel casters and the rear wheel casters are compared with the loads acting on the fixed wheels. The load acting on the wheel caster is small, the rolling resistance of the front wheel caster and the rear wheel caster can be reduced, and the vehicle can easily turn around the fixed wheel. As a result, the turning performance of the transport vehicle is improved.

  In the transport vehicle of the present invention, the distance from the front wheel caster to the fixed wheel may be formed larger than the distance from the fixed wheel to the rear wheel caster. In this way, the steerability of the transport vehicle can be stabilized. In other words, the transport vehicle bends around the fixed wheel, but by making the distance from the front wheel caster to the fixed wheel larger than the distance from the fixed wheel to the rear wheel caster, the rotational moment from the fixed wheel to the front side is increased. Since it can be larger than the rotational moment on the rear side from the fixed wheel, so-called tail swing can be suppressed, and the steering performance becomes stable.

  Moreover, the conveyance vehicle of this invention can also be equipped with the stopper which controls the bending of the said leaf | plate spring member. If it carries out like this, the excessive bending of a leaf | plate spring member can be controlled. As a result, the running performance can be made more stable.

Next, embodiments of the present invention will be described using examples.
FIG. 1 is a side view of a transport vehicle according to an embodiment of the present invention as viewed from the side. FIG. 2 is a bottom view of the transport vehicle with the front wheel caster, the rear wheel caster and the fixed wheel removed, as viewed from the bottom.

The transport vehicle 1 is attached to the bottom of each of a frame 2 formed with a frame, left and right leaf springs 3 and 4 fixed to the bottom side of the frame 2 and a pair of left and right leaf springs 3 and 4. A front wheel caster 7, a rear wheel caster 8, and a fixed wheel 9 are provided.
Further, on the front side of the transport vehicle 1, a handle 14 for pushing and a towing hook 12 protruding forward are provided.

The frame 2 is composed of square members, and a pair of left and right long frame members 2a and 2a and a pair of front and rear short frame members 2b and 2b are framed in a rectangular shape in plan view, and the left and right long frame members 2a, Three reinforcing frame members 2c, 2d, 2e are assembled in a bridging manner between 2a, and these three reinforcing frame members 2c, 2d, 2e are front and rear in parallel with a pair of front and rear short frame members 2b, 2b. It is assembled at intervals in the direction.
A fixing bolt 5 is fastened to the three reinforcing frame members 2c, 2d, and 2e of the frame 2 from below, and a single plate-like plate that is long in the front-rear direction on the bottom side of the reinforcing frame members 2c, 2d, and 2e. The springs 3 and 4 are fixed in a cantilevered manner to the left and right pairs.
The front end sides of the respective leaf springs 3 and 4 have free end portions 3a and 4a that can be bent and deformed in the vertical direction between the short frame material 2b on the front side and the reinforcing frame material 2c. , 4 has free ends 3b, 4b that can be bent and deformed in the vertical direction between the rear short frame member 2b and the reinforcing frame member 2e.

Mounting holes 6, 6, 6 through which four bolts pass are formed at positions where the free ends 3 a, 3 b, 4 a, 4 b of the leaf springs 3, 4 and the reinforcing frame member 2 d of the leaf springs 3, 4 are aligned. A front wheel caster 7 is attached to the mounting holes 6, 6, 6 of the free ends 3 a, 4 a by passing bolts from below and tightening the bolt nuts, and mounting holes 6, 6, 6 of the free ends 3 b, 4 b. A bolt 6 is passed from below to tighten the bolt nut, and the rear wheel caster 8 is mounted. A bolt is passed from below to the mounting holes 6, 6, 6 that are aligned with the reinforcing frame 2 d and fixed by tightening the bolt nut. A wheel 9 is attached.
Here, the distance from the mounting holes 6, 6, 6 of the free ends 3 a, 4 a to the mounting holes 6, 6, 6 at the position aligned with the reinforcing frame member 2 d is the mounting hole at the position aligned with the reinforcing frame material 2 d. It is set to be larger than the distance from 6, 6, 6 to the mounting holes 6, 6, 6 of the free ends 3b, 4b. Therefore, when the front wheel caster 7, the rear wheel caster 8 and the fixed wheel 9 are attached to the leaf springs 3 and 4, as shown in FIG. 1, the longitudinal distance a from the front wheel caster 7 to the fixed wheel 9 is fixed. It becomes larger than the distance b in the front-rear direction from the wheel 9 to the rear wheel caster 8.

  Further, in order to restrict excessive bending of the free end portions 3a, 3b, 4a, 4b on the front side and the rear side of the leaf springs 3, 4, respectively, a pair of short frame members 2b, 2b are provided inside the front and rear short frames 2b, 2b. The front stopper 13a and the pair of rear stoppers 13b are provided so as to protrude substantially horizontally.

  The front wheel caster 7 and the rear wheel caster 8 are attached so that the ground contact surface in a state where the leaf spring members 3 and 4 are not bent is vertically above the contact surface of the fixed wheel 9. That is, when the leaf springs 3 and 4 are not bent, as shown in FIG. 3, only the fixed wheel 9 comes into contact with the floor surface F, and the front wheel casters 7 and the rear wheel casters 8 and the floor surface F A gap S is formed between them. Thus, on a flat ground, both the front wheel caster 7 and the rear wheel caster 8 are in a state in which the leaf springs 3 and 4 are bent vertically downward, that is, the front wheel caster 7 and the rear wheel caster 8 are vertically upward. It will be grounded to the floor F in the state where the force of this acted.

The front wheel caster 7 is provided with a base 7a fixed to the bottom side of the leaf springs 3 and 4 with bolts, and a rotating portion 7b that allows rotation in a horizontal plane at the lower portion of the base 7a. The rotating portion 7b An arm 7c is formed from the bottom to the bottom, and a wheel 7d is rotatably provided on a shaft provided at the lower end of the arm 7c.
Similarly, the rear wheel caster 8 includes a base 8a fixed to the bottom side of the leaf springs 3 and 4 with bolts, a rotating portion 8b that allows rotation in a horizontal plane, an arm 8c, and a wheel 8d. .
The fixed wheel 9 is provided with a base 9a fixed to the bottom side of the leaf springs 3 and 4 with bolts, and an arm 9b that is suspended from the base 9a, and the wheel 9c is rotatable about the lower end shaft of the arm 9b. It is provided.

  Further, in the vicinity of the center in the left-right direction on the bottom side of the frame 2, a fixing plate 10 protrudes forward from the reinforcing frame member 2c and is fixed to the reinforcing frame member 2c and the front short frame member 2b. At the front end of the plate 10, a tow hook 12 that protrudes further forward is provided through the connecting portion 11, and a connecting pin hole 12 a into which a connecting pin can be inserted is provided at the front end of the tow hook 12. It is formed through. A plurality of transport vehicles 1 can be connected by inserting a pin into the connection pin hole 12a.

  Further, the hand handle 14 is inclined upward to the front side at the upper end of the rising portion 14a raised from the frame 2 side, and an inclined portion 14b is formed at the upper end of the inclined portion 14b. A grip bar 14c is formed. The grip bar 14c is gripped with a hand, and the transport vehicle 1 can be moved by hand pressing.

Next, the effect of the transport vehicle 1 configured as described above will be described.
First, consider a case where the transport vehicle 1 travels on a flat ground.
When traveling on flat ground, the transport vehicle 1 includes a pair of front wheel casters 7, a pair of rear wheel casters 8 and a pair of fixed wheels 9 provided on the left and right leaf springs 3 and 4, as shown in FIG. 4. Since all the six wheels are in contact with the floor surface F, the vehicle can travel stably. In addition, the front wheel caster 7 and the rear wheel caster 8 are always grounded to the floor F with the leaf springs 3 and 4 bent, and the front wheel caster 7 and the rear wheel caster 8 are always connected to the plate springs 3 and 4 from the plate springs 3 and 4. Since the urging force is applied vertically upward, the load acting on the front wheel caster 7 and the rear wheel caster 8 is smaller than the load acting on the fixed wheel 9. Therefore, the rolling resistance of the front wheel caster 7 and the rear wheel caster 8 is reduced as compared with the fixed wheel 9, and it becomes easy to turn around the fixed wheel 9, and the carrier vehicle 1 can be easily turned during traveling to change the direction. Can be changed. Further, when the transport vehicle 1 is turned, the direction of the transport vehicle 1 is changed with the fixed wheel 9 as the center. The distance a from the front wheel caster 7 to the fixed wheel 9 is set to the distance a from the fixed wheel 9 to the rear wheel caster 8. Is greater than the distance b, so that the rotational moment from the fixed wheel 9 to the front side can be made larger than the rotational moment from the fixed wheel 9 to the rear, and so-called tail swinging during turning can be suppressed. It will be stable.

Next, consider a case where the front wheel caster 7, the rear wheel caster 8, or the fixed wheel 9 rides on a step on the floor surface F.
FIG. 5 is a state diagram showing a state when the front wheel caster 7 rides on the step Fa, and FIG. 6 is a state diagram showing a state when the rear wheel caster 8 rides on the step Fc. 7 is a state diagram showing a state when the fixed wheel 9 has climbed over the step Fb.
Even if any of the front wheel caster 7, the rear wheel caster 8 or the fixed wheel 9 rides on the steps Fa, Fb, Fc of the floor surface F, the free ends 3a of the leaf springs 3, 4 as shown in FIGS. , 3b, 4a, 4b can be bent and all the wheels can be kept in contact with the floor F, so that the vehicle can travel stably. Here, the case where the front wheel caster 7, the rear wheel caster 8 or the fixed wheel 9 rides on the steps Fa, Fb, Fc of the floor surface F has been described. Needless to say, the effects of the above are achieved.

  Further, since the front stopper 13a and the rear stopper 13b are fixed to the frame 2 above the front end side and the rear end side of the leaf springs 3 and 4, the front and rear free end sides of the leaf springs 3 and 4 are When it is bent excessively upward, the free end side of the leaf springs 3 and 4 comes into contact with the front stopper 13a or the rear stopper 13b, and the excessive bending can be restricted, and the bending is restricted. Thus, the traveling performance of the transport vehicle 1 becomes stable.

  According to the transport vehicle 1 of the embodiment described above, the bottom side of the frame 2 is such that the front and rear ends of the leaf springs 3 and 4 that are long in the front-rear direction are the free ends 3a, 3b, 4a, and 4b. Since the front wheel caster 7 and the rear wheel caster 8 are attached to the free end portions 3a, 4a, 3b, 4b, any of the front wheel caster 7, the rear wheel caster 8, or the fixed wheel 9 can be Even when riding on the dent, the free ends 3a, 4a, 3b, 4b of the leaf springs 3, 4 are satisfactorily bent and all the wheels of the front wheel caster 7, the rear wheel caster 8 and the fixed wheel 9 are always on the floor F. It can be grounded and stable running performance can be ensured. Moreover, the leaf springs 3 and 4 are fixed to the frame 2 so as to have the free ends 3a, 4a, 3b and 4b, and the front wheel caster 7 and the rear wheel caster 8 are fixed to the free ends 3a, 4a, 3b and 4b. Since it is only attached, the structure is simple. Further, since the leaf springs 3 and 4 are each formed in a single plate shape that is long in the front-rear direction, an increase in the number of parts can be suppressed. Furthermore, since the front stopper 13a and the rear stopper 13b that restrict excessive bending of the leaf springs 3 and 4 are provided, the running performance can be further stabilized.

  Further, according to the transport vehicle 1 of the embodiment, the grounding surface of the front wheel caster 7 and the rear wheel caster 8 in a state where the leaf springs 3 and 4 are not bent is vertically above the grounding surface of the fixed wheel 9. Therefore, on a flat ground, the front wheel caster 7 and the rear wheel caster 8 always have the leaf springs 3 and 4 bent vertically downward, that is, the front wheel caster 7 and the rear wheel caster 8 are placed on the floor surface F. It is possible to make a state in which a vertically upward force is applied when making contact with the ground. As a result, the load acting on the front wheel caster 7 and the rear wheel caster 8 can be suppressed to be smaller than the load acting on the fixed wheel 9, and the rolling resistance between the front wheel caster 7 and the rear wheel caster 8 can be reduced. The turning ability centering on can be improved. As a result, the load acting on the front wheel caster 7 and the rear wheel caster 8 can be suppressed to be smaller than the load acting on the fixed wheel 9, and the rolling resistance between the front wheel caster 7 and the rear wheel caster 8 can be reduced. The turning ability centering on can be improved.

  Further, according to the transport vehicle 1 of the embodiment, the front-rear direction distance a from the front wheel caster 7 to the fixed wheel 9 is made larger than the front-rear direction distance b from the fixed wheel 9 to the rear wheel caster 8, The rotational moment on the front side from the fixed wheel 9 can be made larger than the rotational moment on the rear side from the fixed wheel 9. As a result, since so-called tail swing during turning can be suppressed, the steering performance can be stabilized.

  In the transport vehicle 1 of the embodiment, the leaf springs 3 and 4 are provided separately on the left and right, but as illustrated in the transport vehicle 100 of the modified example of FIG. There is no problem as well. In this case, the notches 120a and 120b may be formed in both the front and rear portions of the leaf spring 103 so that the front wheel caster 7 and the rear wheel caster 8 can be bent separately on the left and right.

  In the transport vehicle 1 of the embodiment, the leaf springs 3 and 4 are formed in a single plate shape that is long in the front-rear direction. However, as illustrated in the transport vehicle 200 of the modified example of FIG. 203b, 204a, 204b. Further, as exemplified in the transport vehicle 300 of the modified example of FIG. 10, the plate springs 303 and 304 that are long in the left-right direction instead of the front-rear direction may be used. In this case, the fixing plate 310 is spanned from the front short frame member 303b to the rear short frame member 302b and fixed, and a leaf spring is provided between the reinforcing frame member 302c of the fixing plate 310 and the front short frame member 303b. The plate spring 304 may be fixed in a cantilever manner between the reinforcing frame member 302e of the fixing plate 310 and the rear short frame member 302b. Instead of the fixing plate 310, a separate reinforcing frame member may be fixed from the front short frame member 303b to the rear short frame member 302b, and the leaf springs 303 and 304 may be fixed thereto.

  In the transport vehicle 1 according to the embodiment, the grounding surface of the front wheel caster 7 and the rear wheel caster 8 in a state where the leaf springs 3 and 4 are not bent is vertically above the grounding surface of the fixed wheel 9. Although attached, it may be attached so that only one of the ground contact surfaces of the front wheel caster 7 or the rear wheel caster 8 is vertically above the contact surface of the fixed wheel 9. In this case, it is only necessary to attach the remaining one grounding surface of the front wheel caster 7 or the rear wheel caster 8 to the same height as the grounding surface of the fixed wheel 9. Alternatively, both the front wheel caster 7 and the rear wheel caster 8 may be attached so that the ground contact surface in a state where the leaf springs 3 and 4 are not bent is at the same height as the contact surface of the fixed wheel 9.

  In the transport vehicle 1 of the embodiment, the front-rear direction distance a from the front wheel caster 7 to the fixed wheel 9 is larger than the front-rear direction distance b from the fixed wheel 9 to the rear wheel caster 8, but the front-rear direction distance a May be the same as the front-rear direction distance b, and conversely, the front-rear direction distance a may be smaller than the front-rear direction distance b.

  In the transport vehicle 1 of the embodiment, the front stopper 13a and the rear stopper 13b that restrict excessive bending of the leaf springs 3 and 4 are provided. However, the front stopper 13a and the rear stopper 13b may be omitted.

In the transport vehicle 1 of the embodiment, the left and right leaf springs 3 and 4 are exemplified by one leaf spring, but may have a structure in which two or more upper and lower plates are overlapped. .
Moreover, although the frame 2 illustrated what was framed by the square shape in the planar view with the square material, of course, it is not limited to such a shape.

  As mentioned above, although embodiment of this invention was described using the Example, this invention is not limited to such an Example, In the range which does not deviate from the summary of this invention, it can implement with a various form. Of course.

It is a side block diagram of a conveyance vehicle. It is the bottom line composition figure which looked at a conveyance vehicle from the bottom side in the state where a front wheel caster, a rear wheel caster, and a fixed wheel were removed. It is the side lineblock diagram showing the relation between a front wheel caster, a rear wheel caster, and a fixed wheel when a leaf spring is in a horizontal state. It is a principal part side surface expanded block diagram which shows the relationship of the wheel when it exists in the horizontal state which all the wheels earth | ground on flat ground driving | running | working. It is a principal part expanded side block diagram at the time of the state which the front-wheel caster got on the level | step difference. It is a principal part expanded side block diagram at the time of the state which the rear-wheel caster got on the level | step difference. It is a principal part expansion side surface block diagram at the time of the state which the fixed ring got on the level | step difference. It is the bottom face line configuration figure which looked at the conveyance vehicle of the modification from the bottom side in the state where the front wheel caster, the rear wheel caster, and the fixed wheel were removed. It is the bottom face line configuration figure which looked at the conveyance vehicle of the modification from the bottom side in the state where the front wheel caster, the rear wheel caster, and the fixed wheel were removed. It is the bottom face line configuration figure which looked at the conveyance vehicle of the modification from the bottom side in the state where the front wheel caster, the rear wheel caster, and the fixed wheel were removed.

Explanation of symbols

1,100,200,300 Carriage vehicle 2 Frame 2a Long frame material 2b, 302b, 303b, Short frame material 2c, 2d, 2e Reinforcement frame material 3, 4, 103, 203a, 203b, 204a, 204b, 303, 304 Leaf spring (leaf spring member)
3a, 3b, 4a, 4b Free end 6 Mounting hole 7 Front wheel caster 8 Rear wheel caster 9 Fixed wheel 7a, 8a, 9a Base 7b, 8b Rotating part 7d, 8d, 9c Wheel 12 Towing hook 13a Front stopper 13b Rear part Stopper 14 Hand handle 14c Grip bar

Claims (6)

A transport vehicle comprising a front wheel caster provided on the front side in the traveling direction, a rear wheel caster provided on the rear side in the traveling direction, and a fixed wheel provided between the front wheel caster and the rear wheel caster,
The said front wheel caster and the said rear wheel caster are attached to the free end side of the leaf | plate spring member installed in the cantilever at the bottom part of the said conveyance vehicle.   2. The transport vehicle according to claim 1, wherein the leaf spring member is a single leaf spring installed at the bottom so that the front side in the traveling direction and the rear side in the traveling direction are free ends. The front wheel caster has a left front wheel caster provided on the left side with respect to the traveling direction, and a right front wheel caster provided on the right side with respect to the traveling direction,
The transport vehicle according to claim 1, wherein the rear wheel caster includes a left rear wheel caster provided on the left side with respect to the traveling direction and a right rear wheel caster provided on the right side with respect to the traveling direction. There,
The leaf spring member includes a left leaf spring to which the left front wheel caster and the left rear wheel caster are attached, and a right leaf spring to which the right front wheel caster and the right rear wheel caster are attached.   4. The front wheel caster and / or the rear wheel caster is attached such that a grounding surface in a state where the leaf spring member is not bent is vertically above a grounding surface of the fixed wheel. Or the described transport vehicle.   The transport vehicle according to any one of claims 1 to 4, wherein a distance from the front wheel caster to the fixed wheel is formed larger than a distance from the fixed wheel to the rear wheel caster.   The conveyance vehicle according to any one of claims 1 to 5, further comprising a stopper that restricts the bending of the leaf spring member.

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