JP2008087539A - Motor-driven carrier - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a motor-driven carrier capable of enhancing the operability with a simple constitution. <P>SOLUTION: The motor-driven carrier comprises a vehicle body 1 having a frame 2 while having a steering wheel 3 upwardly at the position behind the frame 2, front wheels 4 arranged on a forward bottom surface of the vehicle body 1, rear wheels 5 arranged on a bottom surface at the forward position of the steering wheel 3 of the vehicle body 1, and a driving wheel 8 arranged between the rear wheels 5 at the forward position of the steering wheel 3 of the vehicle body 1, and further comprises an elevating/lowering device 9 for changing the driving wheel 8 to the condition in contact with a floor surface and the condition not in contact with the floor surface. With this constitution, the driving force of the driving wheel can be used as necessary, and the operability can be enhanced. Further, the heavy driving wheel is arranged on a rear part of the vehicle body, and enables the carrier to easily ride over steps. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to an electric transport vehicle such as a carriage having driving wheels.

Conventionally, as this kind of electric transport vehicle, there has been proposed one that switches between a state in which the driving wheel is grounded on the floor surface and automatically travels and a state in which the driving wheel is floated from the floor surface and is manually driven. . (Patent Document 1)
In Patent Document 1, a caster wheel is provided at the front, a fixed wheel is provided at the rear, a drive wheel is provided at a position behind the caster wheel between the caster wheels, a lifting device for raising and lowering the drive wheel is provided, and the drive wheel is placed on the floor surface. It is configured to perform unattended transport in a grounded state and transport it by manual operation in a state where the driving wheel is lifted from the floor surface.

In addition, a driving wheel is provided in the front, a caster wheel is provided in the rear, a handle is provided in the upper rear portion, a steering direction and an operating force applied to the handle are detected, and the driving wheel is driven based on the detected force. Some have been proposed to assist the operation force. (Patent Document 2)
JP-A-7-33011 JP-A-9-109893

  The drive wheel of Patent Document 1 is driven by a motor disposed near the drive wheel via a speed reduction mechanism, but there is a problem that the configuration is complicated.

  Since the transport vehicles of Patent Documents 1 and 2 have a drive mechanism such as a drive wheel drive motor disposed in front, the front is heavy. When the transport vehicle gets over the level difference, the weight is applied so that the steering wheel is tilted backward, and the front of the transport vehicle is lifted up. There is a problem that it is difficult to lift and overstep.

  In addition, in the transport vehicle of Patent Document 2, a transport vehicle that assists the user's operating force with a motor can only assist at a speed of 6 Km / h or less when traveling on a public road, and a speed higher than that. When it is desired to operate with the motor, there is a problem that the motor becomes a load and the operation becomes heavy.

  In view of such problems, it is an object of the present invention to provide an electric transport vehicle that can improve operability with a simple configuration.

  An electric transport vehicle of the present invention includes a vehicle body having a gantry, front wheels and rear wheels disposed on a bottom portion of the vehicle body, and drive wheels disposed between rear wheels on the vehicle body bottom portion, A lifting device is provided that switches the wheel between a state in which the wheel is in contact with the floor and a state in which the wheel is not in contact with the floor.

  In addition, the electric transport vehicle of the present invention has a gantry and has a vehicle body formed with a handle upward at a position behind the gantry, a front wheel disposed on a bottom surface in front of the vehicle body, and a front side of the handle of the vehicle body. A rear wheel disposed on the bottom surface of the position, and a drive wheel disposed between the rear wheels in front of the handle of the vehicle body, wherein the drive wheel is grounded to the floor surface and grounded to the floor surface An elevating device that switches to a state of not performing is provided.

  It is preferable that the driving wheel is constituted by a driving wheel that has a built-in motor and a pivot shaft that is provided at the center and is supported by the vehicle body and is rotatable, and a tire that is replaceably provided on the outer periphery of the driving wheel.

  The tire is preferably composed of an annular mounting portion that is detachably fixed to the outer periphery of the driving wheel, and a tire portion that is made of a material having a grip property with a floor surface that is integrally formed on the outer periphery of the mounting portion. .

  It is preferable that the front wheel is a caster wheel and the rear wheel is a fixed wheel.

  It is preferable to provide an urging means for urging the drive wheel downward together with the rear wheel in contact with the floor surface.

  It is preferable that the contact point with the floor surface of the drive wheel is set in the vicinity of a line connecting the contact point with the floor surface of the rear wheel.

  According to the present invention, the driving force of the driving wheel can be used as needed by switching the driving wheel between a state in which the driving wheel is grounded on the floor surface and a state in which the driving wheel is not in contact with the floor, thereby improving operability. Can do. In addition, since the heavy driving wheels are arranged behind the vehicle body, it is possible to easily get over the steps.

  In addition, since the drive wheel incorporates the motor, the drive wheel can be made compact, and when the tire is worn, only the tire can be replaced, and the operability can be improved.

  Since the tire is composed of an annular mounting portion and a tire portion that is integrally formed on the outer periphery of the mounting portion, the tire replacement workability can be improved.

  Since the front wheel is a caster wheel and the rear wheel is a fixed wheel, both the ground state and non-ground state of the drive wheel can have the same operability, and the operability can be improved.

  Since the drive wheel is grounded to the floor together with the rear wheels, a biasing means for biasing downward is provided, so that if the floor is uneven or the tire of the drive wheel is worn and the diameter is small Even in such a case, the auxiliary driving force can be obtained by reliably grounding the floor.

  The contact point with the floor surface of the drive wheel is set in the vicinity of the line connecting the contact point with the floor surface of the rear wheel. It is possible to obtain driving force by grounding.

  The embodiment of the present invention will be described in detail below based on the electric cart shown in FIGS.

  First, an example of the handcart according to the present invention will be described with reference to FIG.

  Reference numeral 1 denotes a vehicle body having a synthetic resin frame 2 and a reverse U-shaped handle 3 upward at the rear part of the frame 2 and a pair of front wheels comprising caster wheels on both sides of the front bottom surface of the frame 2. 4. A pair of rear wheels 5 that cannot swing in the front-rear direction from the standing position of the handle 2 on both sides of the rear bottom surface are provided.

  The handle 3 is provided with an operation lever (not shown) that is operated by grasping the handle 3. By operating the operation lever by grasping the handle 3, a brake mechanism (not shown) of the rear wheel 5 is released. When the hand is released, the rear wheel 5 is braked so that the carriage does not move carelessly. The handle 3 is provided with an operation unit 6, and drive wheels 8 described later are driven only while operating a drive switch (not shown) provided on the operation unit 6. Further, the operation unit 6 is provided with a speed selection switch for selecting the rotation speed of the drive wheel 7 and a display unit (none of which is shown) for displaying the selected speed. A battery 7 is detachably attached to the handle 3 and supplies electric power to drive wheels 8 described later to drive the drive wheels 8 to rotate.

  8 is a drive wheel disposed between the rear wheels 5 on the bottom surface of the gantry 2 and is configured to be movable up and down to a position where it is grounded together with the rear wheels 5 by the lifting mechanism 9 and a position where it is not grounded to the floor surface. The buffer body 10 is always urged downward.

  The lifting mechanism 9 for the drive wheel 8 will be described in detail with reference to FIGS. Reference numeral 11 denotes a mounting plate fixed between the rear wheels 5 on the bottom surface of the gantry 2, and a pair of pivotal support portions 12 are formed at the front portion. Reference numeral 13 denotes a support frame that is pivotally supported on the pivot 12 and supported on the mounting plate 11 in a swingable manner. The support frame 13 is formed in a substantially U shape having a top surface and both side walls. The fixing groove 15 into which the support shaft 41 for fixing the driving wheel 8 is inserted and fixed is formed at the rear of both side surfaces so as to open downward. A blocking member 16 that closes the lower side of the fixing groove 15 is detachably attached to the lower side of the side surface of the support frame 13, and the fixing support shaft 41 for fixing the driving wheel 8 falls out of the lower opening of the fixing groove 15 by the blocking member 16. Is preventing. The drive wheel 8 is positioned below the ground contact point with the floor surface of the pair of rear wheels 5 when the fixing support shaft 41 is in contact with the blocking member 16.

  A spring 17 is provided between the mounting plate 11 and the side surface of the support frame 13 to urge the support frame 13 upward. The shock absorber 10 is installed between the receiving portion 18 projecting outward from the side surface of the support frame 13 and the support shaft 41 for fixing the drive wheel 8, and absorbs an impact from the floor surface received by the drive wheel 8, The driving wheel 8 is pressed against the floor surface to obtain driving force.

  Reference numeral 19 denotes a support plate that is suspended from the rear portion of the mounting plate 11, and supports a link mechanism 20 described later.

  Reference numeral 20 denotes a link mechanism for ascending and descending the drive wheel 8. A pedal 21 is provided at one end located behind the vehicle body 1, and a pivot shaft 22 at the center is pivotally supported on the support plate 19. A first link plate 23, a second link plate 25 having one end pivotally supported by the other end of the first link plate 23 and a pivot shaft 24 of the other end pivotally supported by a side surface of the support frame 13, and the first link plate 23 A fixed pin 26 projecting outward from the shaft support portion of the link plate 23 and the second link plate 25, and an upper portion fixed to the support plate 19 and a lower portion fixed to the support plate 19. A guide shaft 28 supported by the support plate 19 and the fixed plate 27, a cam plate 29 supported by the guide shaft 28 so as to be swingable and slidable in the axial direction, and fixing the guide shaft 28. It is arranged between the plate 27 and the cam plate 29, and when the free end of the cam plate 29 is urged upward, A spring 30 that biases the cam plate 29 toward the support plate 19, and is installed on one end side of the mounting plate 11 and the first link plate 23, and biases one end side of the first link plate 23 upward. And a spring 31.

  The cam plate 29 is formed in a substantially L shape with its lower end bent toward the fixing pin 26 to form a lower end surface 32, and the lower end surface 32 is fixed to the fixing pin 26 by the biasing force of the spring 31. Are held in contact with the The cam plate 29 includes a cam surface 33 that abuts the fixing pin 26 to push down the cam plate 29 when the pedal 21 is depressed to push down one end side of the first link plate 23, the other end of the first link plate 23, and the first link plate 23. When the two link plates 25 are substantially straight, the fixing pin 26 that has passed over the cam surface 33 is fitted, and a concave portion 34 that prevents the fixing pin 26 from moving, and a side of the concave portion 34 that faces the cam surface 33. When the pedal 21 is further stepped on from the state where the fixing pin 26 is fitted in the recess 34, the distal end of the fixing pin 26 is slidably contacted with the curved surface by being curved at the edge portion. The cam plate 29 has a guide portion 35 that presses the plate 29 in the direction of the fixed plate 27 and separates the fixed pin 26 from the concave portion 34. Turn upward And, a state where the lower end surface 32 comes into contact with the fixed pin 26. Since the recess 34 is formed at a position above the lower end surface 32, the detached fixing pin 26 does not fit into the recess 34 again.

  Next, the configuration of the drive wheel 8 will be described in detail with reference to FIGS. The driving wheel 8 includes a motor 38 having a stator 36 and a rotor 37, a driving wheel 40 that is housed in the motor 38 and is rotationally driven by the rotation of the motor 38 by the motor 38 and the planetary gear reduction mechanism 39, and the driving wheel 40. And a support shaft 41 for fixing projecting to the outer side of the driving wheel 40 and a tire 42 fixed to the outer periphery of the driving wheel 40 in a replaceable manner.

  The moving wheel 40 is constituted by a substantially cup-shaped main body 43 having an opening at the center of the bottom surface and opening the entire surface on the opposite side, and a lid plate 44 covering the opening of the entire surface.

  As shown in FIG. 7, the rotating shaft 37a of the rotor 37 and the fixing support shaft 41 protruding from both ends are arranged on a straight line.

  The tire 42 is disposed on the outer periphery of the driving wheel 40, and is an annular metal mounting portion 45 that is detachably fixed to the driving wheel 40 by a plurality of bolts, and the mounting portion 45 is integrally formed on the outer periphery of the mounting portion 45. The tire portion 46 is made of a material having grip properties with respect to the floor surface to be attached to the tire. The tire portion 46 is made of, for example, rubber. And when the tire part 46 is worn out, the tire 42 can be replaced by removing the bolts.

  Thus, the cart is manually pushed while the drive wheel 8 is positioned above (see FIG. 3) and is not in contact with the floor. When the handle 3 is gripped, the operating lever is operated and the brake of the rear wheel 5 is released. In this state, by pushing the handle 3, it can be pushed in the same manner as a normal cart.

  When loading a heavy object or pushing a carriage on an uphill, the driving wheel 8 is grounded as necessary, and the carriage is operated by using the driving force of the driving wheel 8 as an auxiliary.

  The operation of grounding the drive wheel 8 on the floor will be described. When the pedal 21 is stepped on, the fixed pin 26 moves while sliding on the lower end surface 32 of the cam plate 29 to reach the cam surface 33 (see FIG. 5), and the fixed pin 26 slides on the cam surface 33 so that the cam plate 29 Is pushed down, the fixing pin 26 gets over the cam surface 33 and fits into the recess 34, and the movement of the fixing pin 26 is prevented (see FIG. 4).

  In this state, the other end side of the first link plate 23 and the second link plate 25 are substantially linear, and the distance between the swing shaft 22 of the first link plate 23 and the swing shaft 24 of the second link plate 25 is as follows. By spreading, the rear side of the support frame 13 is pushed down, and the drive wheels 8 are grounded to the floor surface.

  In this state, the handle 3 is gripped to release the brake of the rear wheel 8, the operation switch of the operation unit 6 disposed on the handle 3 is operated to drive the drive wheel 8, and the cart is driven by the drive force of the drive wheel 8. To operate. The rotational speed of the drive wheel 8 can be selected by a speed selection switch of the operation unit 6.

  When climbing over a step, the handle 3 is pulled backward and the front of the carriage is lifted, but the heavy driving wheel 8 is located on the rear side of the carriage, and there is no heavy article on the front side, so the front of the carriage is easy. It is possible to float over the steps, and to easily get over the steps. In addition, since the ground contact point with the floor surface of the drive wheel 8 is located almost on the line connecting the ground contact point with the floor surface of the pair of rear wheels 8, In addition, the driving wheel 8 can be surely brought into contact with the floor surface, and the auxiliary driving force by the driving force of the driving wheel 8 can be continuously obtained. That is, in the configuration in which the grounding point with the floor surface of the driving wheel 8 is located on the front side of the line connecting the grounding point with the floor surface of the pair of rear wheels 5, the driving wheel 8 is in a state where the front of the carriage is floated. Does not come into contact with the floor and no auxiliary driving force can be obtained. Conversely, in a configuration in which the grounding point with the floor surface of the driving wheel 8 is located behind the line connecting the grounding point with the floor surface of the pair of rear wheels 5, the load is applied to the driving wheel 8 when the front of the carriage is lifted. As a result, the life of the motor 38 is shortened, and one or both of the rear wheels 5 are lifted off the floor surface, causing the running of the carriage to become unstable.

  When the drive wheel 8 is moved to a position where it floats from the floor surface, when the pedal 21 is stepped on again, the fixing pin 26 is pushed toward the guide portion 35 formed on the peripheral edge of the recess 34 facing the cam surface 33, The head of the fixed pin 26 slides on the surface of the guide portion 35 on the support plate 19 side to move the cam plate 29 to the fixed plate 27 side, and the fixed pin 26 is detached from the recess 34. The free end side of the cam plate 29 rotates upward due to the elasticity of the spring 30, and the fixing pin 26 contacts the lower end surface 32 of the cam plate 29, thereby preventing the cam plate 29 from swinging. In this state, when the foot is released from the pedal 21, the fixing pin 26 slides on the lower end surface 32, and the support frame 13 is pulled upward by the elasticity of the spring 17, and the driving wheel 8 moves to the upper position.

  Since the front wheel 4 is a caster wheel and the rear wheel 5 is a fixed wheel, the same operability can be achieved whether the drive wheel 8 located between the rear wheels 5 is grounded or not grounded. The user-friendliness is the same and the operability can be improved.

  In addition, although this embodiment demonstrated using what used this invention for the trolley | bogie, you may employ | adopt for other forms of conveyance vehicles, such as an automatic guided vehicle and a dining cart.

It is an external appearance perspective view of the trolley | bogie which shows one Embodiment of this invention. It is the principal part enlarged view. It is a principal part expanded sectional view which shows the state in which the drive wheel was located upwards. It is a principal part expanded sectional view which shows the state which the driving wheel grounded. It is a principal part expanded sectional view which shows the process in which the drive wheel transfers to a grounding state. It is an external appearance perspective view of the drive wheel. It is sectional drawing of the drive wheel.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Car body 2 Base 3 Handle 4 Front wheel 5 Rear wheel 8 Drive wheel 9 Lifting mechanism 10 Shock absorber

Claims (7)

  A vehicle body having a gantry, front wheels and rear wheels disposed at the bottom of the vehicle body, and drive wheels disposed between the rear wheels of the vehicle body bottom, and grounding the drive wheels to the floor surface The electric vehicle characterized by providing the raising / lowering apparatus which switches between a state and the state which does not ground on a floor surface.   A vehicle body having a gantry and having a handle formed upward at a rear position of the gantry, a front wheel disposed on a bottom surface in front of the vehicle body, and a rear wheel disposed on a bottom surface in front of the vehicle body handle And a drive wheel disposed between the rear wheels at a position forward of the handle of the vehicle body, and provided with an elevating device that switches the drive wheel between a state of grounding to the floor and a state of not grounding to the floor An electric vehicle characterized by that.   2. The drive wheel includes a driving wheel that has a built-in electric motor and a pivot shaft that is provided at a center and is supported by the vehicle body and is rotatable, and a tire that is provided on an outer periphery of the driving wheel. Or the electric vehicle of 2 description.   The tire includes an annular mounting portion that is detachably fixed to the outer periphery of the driving wheel, and a tire portion that is made of a material having gripping properties with a floor surface that is integrally mounted on the outer periphery of the mounting portion. The electric transport vehicle according to claim 3.  The electric transport vehicle according to claim 1 or 2, wherein the front wheels are caster wheels and the rear wheels are fixed wheels.   3. The electric transport vehicle according to claim 1, further comprising an urging means for urging the drive wheel downward with the rear wheel in contact with the floor surface.   The electric vehicle according to claim 1 or 2, wherein a grounding point with the floor surface of the drive wheel is set in the vicinity of a line connecting the grounding point with the floor surface of the rear wheel.