WO2021117086A1

WO2021117086A1 - Conveying vehicle

Info

Publication number: WO2021117086A1
Application number: PCT/JP2019/048056
Authority: WO
Inventors: 欣也河野; 玄人足立; 宣人武藤
Original assignee: 武蔵精密工業株式会社
Priority date: 2019-12-09
Filing date: 2019-12-09
Publication date: 2021-06-17

Abstract

This conveying vehicle comprises: a dolly main unit running-enabled via left and right drive wheels; a pair of running motors enabled for rotationally driving the left and right drive wheels independently of each other; left and right forks, extending from a fork base unit and enabled for carrying and supporting a transported object; a raising/lowering drive device that raises and lowers the fork base unit with respect to the dolly main unit; left and right driven wheels attached to the left and right forks; and a raising/lowering link mechanism that raises and lowers the left and right forks with the driven wheels as the fulcrum, in linked movement with the raising/lowering displacement of the fork base unit with respect to the dolly main unit. Provided is the conveying vehicle, wherein: the left and right drive wheels (W1) are attached in a non-steerable manner to the dolly main unit (10); and the left and right driven wheels (W2) are attached in a steerable manner to the left and right forks (F) via support bases (35). Due to this configuration: the need for a swiveling mechanism between the dolly main unit and the left and right drive wheels/the running motors is eliminated, thereby serving to lighten the weight and save on the cost of the vehicle; and moreover, smooth and accurate moving and swiveling of the vehicle to the transported object is made possible, thereby achieving exact positional alignment with the transported object.

Description

Transport vehicle

The present invention relates to a transport vehicle, particularly a transport vehicle capable of unmanned traveling to a desired location under the control of a traveling motor, supporting the transported object on a fork, and lifting and transporting the transported object.

The transport vehicle is conventionally known, for example, as disclosed in Patent Document 1. In this vehicle, a drive unit having left and right drive wheels and a motor for independently driving them is configured independently of the bogie body. It is also attached to the bogie body via a swivel mechanism.

Japanese Patent Application Laid-Open No. 2019-111972

In the above-mentioned conventional transport vehicle, since the drive unit configured separately from the bogie body is attached to the bogie body via a turning mechanism, the traveling drive system as a whole becomes structurally complicated and costs increase. There's a problem.

The present invention has been made in view of such circumstances, and an object of the present invention is to provide a transport vehicle capable of solving the above problems of the conventional structure.

In order to achieve the above object, the present invention presents a bogie body, left and right drive wheels that are non-steerably attached to the bogie body, and a pair of traveling motors capable of rotating and driving the left and right drive wheels independently of each other. The left and right forks that extend from the fork base and can place and support the transported object, the elevating drive device that raises and lowers the fork base with respect to the bogie body, and the left and right forks are steered via the support bases, respectively. The first feature is that it is provided with left and right driven wheels that can be freely attached and an elevating link mechanism that raises and lowers the left and right forks with the driven wheels as fulcrums in conjunction with the elevating and lowering displacement of the fork base with respect to the bogie body. And.

Further, in addition to the first feature, the present invention has a posture holding means for keeping the mounting posture of the support base with respect to the fork constant so that the driven wheel can always be steered around the vertical axis. It is the feature of 2.

Further, in the present invention, in addition to the first or second feature, the elevating link mechanism is a connecting link paired with a relay link that moves substantially along the longitudinal direction of the fork in conjunction with the elevating displacement. The parallel link mechanism includes a parallel link mechanism that is configured by pivotally connecting the fork and the support base and raises and lowers the support base in a constant mounting posture in conjunction with the movement of the relay link. The third feature is that it is also used as the posture holding means.

Further, in the present invention, in addition to the first to third features, a position information acquisition unit capable of acquiring the position information of the insertion portion of the transported object into which the fork is inserted and the position information acquisition unit thereof acquire the position information. A fourth feature is that the vehicle is provided with a travel control device that controls the pair of travel motors based on the position information of the insertion portion.

Further, in the present invention, in addition to the first to fourth features, a lower shape information acquisition unit capable of acquiring information on the lower shape of the insertion hole into which the fork is inserted, and the lower shape information thereof. A fifth feature is that it is provided with an elevating control device that controls the elevating drive device based on the information on the lower shape acquired by the acquisition unit.

In the present invention, the "lower shape of the insertion hole" means the open shape of the lower part of the insertion hole in the case of an insertion hole whose lower surface is open, and a member such as a beam that crosses the insertion hole is the insertion hole. When it exists in the lower part of the member, it means the shape of the member (for example, the shape and height of the upper surface of the member).

According to the first feature of the present invention, the left and right drive wheels that are non-steerably attached to the bogie body, a pair of traveling motors capable of rotating and driving the left and right drive wheels independently of each other, and extending from the fork substrate. Left and right forks that can mount and support the transported object, an elevating drive device that raises and lowers the fork base with respect to the bogie body, and left and right driven wheels that can be steered freely via the support bases to the left and right forks, respectively. Since it is equipped with an elevating link mechanism that raises and lowers the left and right forks with the driven wheels as fulcrums in conjunction with the elevating and lowering displacement of the fork base with respect to the bogie body, the left and right drive wheels are mounted on the bogie body so that they cannot be steered. The vehicle can be turned by rotating both drive wheels independently on the left and right with a pair of traveling motors. Therefore, it is not necessary to provide a turning mechanism between the left and right drive wheels and the traveling motor and the bogie body, and the structure is simplified, which can contribute to weight reduction and cost reduction of the vehicle. Further, since the driven wheel that can be steered with respect to the fork can easily follow the turning of the vehicle and turn, the vehicle can be smoothly moved and turned to the target vehicle.

Further, according to the second feature, since the driven wheel has a posture holding means for keeping the mounting posture of the support base with respect to the fork constant so that the driven wheel can always steer around the vertical axis, the driven wheel supports the constant posture. It is attached to the fork via the base, and the driven wheel can always be smoothly steered to turn the vehicle regardless of the elevating position of the fork.

Further, according to the third feature, the elevating link mechanism is a relay link that moves substantially along the longitudinal direction of the fork in conjunction with the elevating displacement of the fork base with respect to the trolley body, and a pair of connecting links for the fork and the supporting base. A part of the elevating link mechanism (parallel link mechanism) is in an attitude because it is configured by pivotally connecting the spaces and is provided with a parallel link mechanism that raises and lowers the support base in a fixed mounting posture in conjunction with the movement of the relay link. It will also be used as a holding means, and the structure will be simplified accordingly, which can contribute to cost reduction.

Further, according to the fourth feature, the traveling motor is controlled based on the position information acquisition unit capable of acquiring the position information of the insertion portion of the transported object and the position information of the insertion portion acquired by the position information acquisition unit. Since it is equipped with a travel control device, when the vehicle reaches the vicinity of the target transported object, even if the position and orientation of the inserted portion of the transported object are slightly deviated, the traveling control is performed based on the position information of the inserted portion. The device controls the traveling motor to move and turn the vehicle, so that the fork can be accurately and accurately inserted into the insertion site of the conveyed object.

Further, according to the fifth feature, a lower shape information acquisition unit capable of acquiring information on the lower shape of the insertion hole of the transported object, and an elevating drive device based on the lower shape information acquired by the lower shape information acquisition unit. Since it is equipped with an elevating control device that controls the elevating and lowering, if there is an obstacle such as a beam that may interfere with the tip of the fork at the lower part of the insertion hole, elevating and lowering based on the information of the lower part shape. By having the control device control the elevating drive device to raise and lower the fork, it is possible to effectively prevent the tip of the fork from colliding with a beam or riding on it, and the fork can be accurately inserted into the insertion hole. Can be done.

FIG. 1 is an overall perspective view showing a forklift according to the first embodiment of the present invention. (First Embodiment) FIG. 2 is a side view of the forklift (2 arrow view of FIG. 1). (First Embodiment) FIG. 3 is a front view of the forklift as viewed from the front with the fork contour as a two-dot chain line. (First Embodiment) FIG. 4 is a vertical sectional view of a main part of the forklift (cross-sectional view taken along line 4-4 of FIG. 3). (First Embodiment) FIG. 5 is an enlarged cross-sectional view taken along line 5-5 of FIG. (First Embodiment) FIG. 6 is an enlarged cross-sectional view taken along line 6-6 of FIG. (First Embodiment) FIG. 7 is an enlarged cross-sectional view taken along line 7-7 of FIG. (First Embodiment) FIG. 8 is an enlarged cross-sectional view taken along line 8-8 of FIG. (First Embodiment) FIG. 9 is a vertical sectional view of a main part of the forklift (cross-sectional view corresponding to FIG. 4) showing a state in which the fork is in the ascending limit. (First Embodiment) 10A and 10B are perspective views of a main part of the fork, in which FIG. 10A shows a state in which the fork is in the descending limit, and FIG. 10B is a diagram showing a state in which the fork is in the ascending limit. (First Embodiment) FIG. 11 shows a specific example of the pallet, (a) shows an example in which the height of the lower shape (beam) of the insertion hole is low, and (b) is the height of the lower shape (beam) of the insertion hole. It is a figure which shows an example which is high. (First Embodiment) FIG. 12 shows an example of the control process of inserting a fork into a pallet having a high lower shape (beam) of the insertion hole, and FIG. 12A shows a state in which the fork is approaching the insertion hole. FIG. 12B is a diagram showing a process of raising the fork by a predetermined amount in advance from the state of FIG. 12A and then inserting the fork into the insertion hole. (First Embodiment) FIG. 13 shows a peripheral portion (posture holding means) of the driven wheel of the forklift according to the second embodiment, (a) shows a state in which the fork is in the descending limit, and (b) shows the fork in the ascending limit. It is a figure which shows a certain state. (Second Embodiment)

C ..... traveling control device-electronic control device as an elevating control device F ..... fork Fb ..... fork bases h1, h2 ... insertion holes L3; L4 , L5 ... Relay link constituting the parallel link mechanism; Paired connecting link M ..... Traveling motor PL, PL'... Parallel link mechanism V as a posture holding means ...・ Forklifts W1, W2 as transport vehicles ・・・ Drive wheels, driven wheels 10 ・・・・・・ Cart body 20 ・・・・・・ Elevating

drive device

30, 30 ′ ・・ Elevating

link mechanism

35, 35 ′ ・・ Support base 61 ・・・・・・ Position information acquisition unit ・ Camera 62 as lower shape information acquisition unit ・・・・・・

Distance sensors

71, 72 as position information acquisition unit ・・・ Pallet as transported object

Embodiments of the present invention will be described below based on preferred embodiments of the present invention shown in the accompanying drawings.

First Embodiment

First, the first embodiment will be described with reference to FIGS. 1 to 12.

The forklift V as a transport vehicle rotates and drives the trolley body 10, the left and right drive wheels W1 that are attached to the trolley body 10 without a turning mechanism (and therefore cannot be steered), and the left and right drive wheels W1 independently of each other. A pair of possible traveling motors M, left and right forks F on which the pallet 71 as a transported object can be placed and supported, and left and right driven wheels that can be steered and supported on the left and right forks F via support bases 35, respectively. It is equipped with W2 and can run unmanned.

In this specification, the direction in which the fork F extends when viewed from the bogie body 10 is defined as "forward". Further, in the present specification, the road surface E means the traveling surface of the forklift V (that is, the rolling surface of the driving wheels W1 and the driven wheels W2) outdoors or in a workplace (for example, a warehouse, a factory, etc.), and the floor surface of the workplace. Of course, it also includes the outdoor ground. At least one article can be loaded on the pallet 71, and the forklift V can convey each article on the pallet 71.

A pair of left and right wheel support frames 11 are fixed to the lower surface of the bogie body 10 at intervals in the vehicle width direction, and each wheel support frame 11 is not shown to rotatably support the axle of the corresponding drive wheel W1. Bearing part is provided. A traveling motor M is fixed and supported on each wheel support frame 11, and the output shaft of the motor M is directly connected to the axle of the drive wheel W1 or is coupled via a reduction mechanism.

Since the bogie body 10 is supported on the road surface E via drive wheels W1 for each of the left and right wheels, it cannot maintain a horizontal posture by itself. However, in the present embodiment, the bogie body 10 and the fork are described later. By interlocking and connecting the Fs to each other and supporting each other, each of them is maintained in a horizontal posture.

Further, the lower end of the rectangular parallelepiped frame frame 12 is fixed to the upper surface of the carriage body 10, and a cover body 13 covering the rectangular parallelepiped frame frame 12 is detachably attached to the frame frame 12 by a fixing means (not shown). Further, on the upper surface of the carriage body 10, a battery 14 as a power source capable of storing electricity and an electronic control device C as a control device are installed and fixed inside the frame frame 12.

The front side of the bogie body 10 is covered with a fork base Fb extending in the vertical direction, and the fork base Fb is formed in a hollow box shape with an open rear surface. The base end portions of the left and right forks F extending horizontally and linearly from the lower wall portion of the fork substrate Fb are polymerized and integrally bonded to the lower wall portion. Therefore, the fork base Fb and the fork F are configured as a rigid frame having an L-shaped side view as a whole.

The left and right forks F are each composed of an elongated linear frame body (more specifically, a channel frame having a U-shaped cross section open downward) that can be inserted and removed from the insertion hole h1 provided in the pallet 71. Each of the tip portions is formed in a tapered shape in a plan view and a side view so as to facilitate the insertion of the insertion hole h1. Thus, the upper surface of the fork F is a flat surface on which the conveyed object is placed, and the internal space of the fork F can accommodate at least a part of the elevating link mechanism 30 described later.

A camera 61 capable of photographing a target object in front of the fork F and capturing it as image data is fixed to the lower wall portion of the fork base Fb between the left and right forks F. Further, a pair of left and right distance sensors 62 (for example, a radar type rangefinder) capable of measuring the distance to the front target are fixed to the lower wall portion of the fork base Fb on the outer side in the left-right direction of each fork F.

The forklift V is an elevating drive device 20 that elevates and lowers the fork base Fb with respect to the bogie body 10, and an elevating link that elevates and lowers the left and right forks F with the driven wheel W2 as a fulcrum in conjunction with the elevating displacement of the fork base Fb with respect to the bogie body 10. The mechanism 30 and the posture holding means PL for keeping the mounting posture of the support base 35 with respect to the fork F constant so that the driven wheel W2 can always be smoothly steered around the vertical axis are further provided.

Therefore, the fork F is interlocked and connected to the bogie main body 10 so as to be vertically displaced via the elevating drive device 20 and the elevating link mechanism 30. Next, specific examples of the elevating drive device 20 and the elevating link mechanism 30 will be described in sequence.

The elevating drive device 20 includes a plurality of guide struts 21 erected on the trolley main body 10, and an elevating pedestal 22 that is slidably guided and supported on the trolley main body 10 in a constant posture via the guide struts 21. The elevating interlocking mechanism 23 that elevates and lowers the fork base Fb in conjunction with the elevating and lowering of the elevating table 22, the actuator A for elevating and lowering drive fixed on the bogie body 10, and the elevating table by the rotational driving force output by the actuator A. It is provided with a feed screw mechanism 24 that moves the 22 up and down. The actuator A includes, for example, an elevating motor (not shown) and a deceleration mechanism that decelerates and outputs the rotation of the motor.

The feed screw mechanism 24 is a screw shaft that extends in the vertical direction while being supported by a support frame 25 that integrally connects the guide columns 21 to each other and a gear box 29 that is fixed to the trolley body 10 so as to be rotatable and axially immovable. It has a 24b and a nut member 24n that is screwed onto the screw shaft 24b and fixed to the lift 22. Then, the screw shaft 24b and the horizontal output shaft of the actuator A rotate in conjunction with each other in the gear box 29 via, for example, a gear interlocking mechanism (not shown) including a pair of bevel gears. Therefore, when the screw shaft 24b is rotationally driven by the actuator A, the nut member 24n, and thus the elevating table 22 is elevated and driven in conjunction with this.

Further, the elevating interlocking mechanism 23 is pivotally connected to the frame frame 12 on the bogie body 10 via the pivot P1 at one end and rotatably at the upper end of the fork base Fb via the pivot P2. A pair of left and right first elevating links L1 that are pivotally connected, one end is rotatably pivotally connected to the lower part of the bogie body 10 via the pivot P3, and the other end is pivotally connected to the lower part of the fork substrate Fb via the pivot P4. A pair of left and right second elevating links L2 that are rotatably pivotally connected, and a pressing member 27 that is fixed on the elevating table 22 and can push up each first elevating link L1 as the elevating table 22 rises. And have.

Both ends of the pivot P1 are supported by the left and right side frame portions of the frame frame 12, and both ends of the pivot shaft P2 are supported by brackets on the inner surface of the front wall portion of the fork base Fb. Further, the intermediate portion of the pivot P3 is supported on the lower surface of the carriage body 10 via a bracket, and both ends of the pivot P4 are supported by the left and right wall portions of the fork base Fb.

When the lift 22 is driven ascending by the actuator A, the left and right first lift links L1 are pushed up by the pressing member 27 and tilted upward around the pivot P1, following and interlocking with the left and right second lift links L2. Tilts upward around the Axis P3. It should be noted that the lower wall portion of the fork substrate Fb and the base end portion of the fork F polymerized and fixed thereto avoid interference with the second elevating link L2 as is clear from FIGS. 4, 6 and 9. A slit is formed for the purpose.

In the first and second elevating links L1 and L2, the distance between the axes P1 and P3 on the bogie body 10 side and the distance between the axes P2 and P4 on the fork base Fb side are set to be substantially the same. Will be done. Therefore, since the second elevating link L2 also tilts upward by substantially the same amount in conjunction with the upward tilt of the first elevating link L1, the fork F moves up and down with respect to the bogie body 10 while maintaining a substantially horizontal constant posture. ..

The pressing surface 27a of the pressing member 27 that comes into contact with the first elevating link L1 is formed on a medium-high curved surface (for example, an arc surface). As a result, when the first elevating link L1 is pushed up by the pressing member 27 and tilts upward around the pivot P1, the sliding contact portion between the pressing surface 27a and the first elevating link L1 can move smoothly.

Further, as is clear from FIGS. 1, 4 and 5, a pair of guide plates 28 for slidably sandwiching the first elevating link L1 are firmly installed on the elevating table 22 on both sides of the pressing member 27. By the guide action of both guide plates 28, the first elevating link L1 can always be brought into contact with the pressing surface 27a in an appropriate posture.

Next, the support mechanism 40 of the driven wheel W2 will be described with reference to FIGS. 3 and 4. This support mechanism 40 is a wheel support mechanism similar to a conventionally known universal caster, and it has a support frame that rotatably supports a driven wheel W2 around a horizontal axis and a support frame (hence, a driven wheel W2). It has a mounting seat that supports it around the vertical axis (that is, it can be steered freely). It is desirable that the horizontal axis and the vertical axis are offset to some extent in the horizontal direction, whereby the driven wheel W2 can be smoothly steered in the same manner as the conventionally known universal casters.

Then, the mounting seat is joined and fixed (for example, screwed) to the support base 35 which is the mounting frame of the support mechanism 40. The support base 35 is formed in a U-shape with a cross section open to the lower side.

Further, the elevating link mechanism 30 is provided in pairs on the left and right corresponding to the left and right forks F. Each elevating link mechanism 30 is substantially along the longitudinal direction of the fork F in conjunction with the elevating displacement of the second elevating link L2 and the fork base Fb (thus, the vertical rotation of the second elevating link L2 around the pivot P3). It is provided with a relay link L3 that moves by moving, and a parallel link mechanism PL that raises and lowers the support base 35 in a constant mounting posture in conjunction with the movement of the relay link L3. The rear end of the relay link L3 rotatably supports the corresponding second elevating link L2 (more specifically, the portion protruding downward between the Axis P3 and the Axis P4) via the Axis P5. Be connected.

The parallel link mechanism PL is configured by pivotally connecting the fork F and the support base 35 with the fourth and fifth connecting links L4 and L5, each of which forms a pair on the left and right, via the pivots P7 to P10. That is, one end of the left and right fourth connecting links L4 is rotatably pivotally connected to the front end of the relay link L3 via the pivot P6, and the intermediate portion is pivotally connected to the left and right wall portions of the fork F. The other end is rotatably pivotally connected to the left and right wall portions of the support base 35 via the pivot P8. On the other hand, one end of the left and right fifth connecting links L5 is rotatably pivotally connected to the left and right wall portions of the fork F via the pivot axis P5, and the other end portion is connected to the left and right wall portions of the support base 35. It is rotatably pivotally connected via the pivot P10.

Then, the inter-axis distance between the pivots P7 and P9 in the fork F and the inter-axis distance between the pivots P8 and P10 in the support base 35 are the same as each other.

Thus, in a state where the fork F is in the descending limit and the relay link L3 is in the retracting limit (see FIGS. 2, 4 and 10 (a)), the relay link L3 is interlocked and connected via the pivot P6. The fourth and fifth connecting links L4 and L5 are respectively in the prone position, and the support base 35 (hence, the driven wheel W2) is held in the standby position closest to the upper wall portion of the fork F. As a result, the fork F is placed at the lowest position, that is, the descending limit.

Then, from this state, the fork substrate Fb is displaced ascending by the elevating drive device 20, and when the relay link L3 is moved and displaced forward while slightly tilting in conjunction with this, it is interlocked and connected to the relay link L3 via the pivot P6. The fourth and fifth connecting links L4 and L5 stand up and rotate downward around the pivots P7 and P9 with respect to the fork F, so that the support base 35 (hence, the vertical turning axis of the driven wheel W2) is in a constant posture. As it is, it moves downward to an overhang position separated downward from the fork F. As a result, the fork F can be displaced with respect to the road surface E with the driven wheel W2 as a fulcrum to the ascending limit shown in FIGS. 9 and 10B, and the pallet 71 can be lifted.

As described above, in the present embodiment, the parallel link mechanism PL, which is a part of the elevating link mechanism 30, is also used as the posture holding means for the support base 35.

Thus, if the elevating table 22 (and therefore the pressing member 27) rises and falls in response to the rotation of the actuator A, the first and second elevating links L1 and L2 move in conjunction with this, and the pivots P1 and P2 with respect to the bogie body 10. By rotating upward and downward, the fork base Fb is raised and lowered, and in conjunction with this, the elevating link mechanism 30 raises and lowers the fork F with the driven wheel W2 as a fulcrum. As a result, the fork F is displaced ascending / descending while maintaining the horizontal posture.

Further, as is clear from FIGS. 1, 7, 8 and 10, the left and right forks F are provided with a first viewing window Fw1 so that the support base 35 faces the support base 35 when the support base 35 is in the standby position. , A pivot connection portion (that is, a pivot P6) between the relay link L3 and the fourth connection link L4 and a second viewing window Fw2 that exposes the peripheral portion thereof upward are provided. Thus, the first and second viewing windows Fw1 and Fw2 can be used as work windows for inspection and maintenance and disassembly and assembly of a part of the elevating link mechanism 30, particularly the parallel link mechanism PL and its peripheral portion.

Further, between the bogie body 10 and the fork base Fb, a lower limit sensor 63 and an upper limit sensor 64 that can detect that the elevating platform 22 (hence, the fork F) is in a predetermined lowering limit and ascending limit are provided. The lower limit sensor 63 and the upper limit sensor 64 are composed of, for example, a proximity switch capable of detecting the approach of a detection piece (not shown) fixed to the fork substrate Fb.

By the way, the electronic control device C fixed on the bogie body 10 is provided with a microcomputer, and on the input side of the electronic control device C, for example, in addition to the battery 14, a forklift V of a traveling route to be traveled for pallet transportation is provided. The route information acquisition unit Iz for acquiring information, the position information acquisition unit Ix capable of acquiring the position information of the insertion portion (that is, the insertion hole h1) of the pallet 71 into which the fork F is inserted, and the fork F of the pallet 71. The lower shape information acquisition unit Iy that acquires the information on the lower shape of the insertion hole h1 into which the insertion hole h1 is inserted, the lower limit sensor 63 and the upper limit sensor 64 described above, a receiver that receives an output signal from an operation unit described later, and the like are connected. Will be done.

Further, on the output side of the electronic control device C, for example, the left and right traveling motors M, the elevating drive device 20 (more specifically, the elevating motor built in the actuator A), the position signal of the forklift V, and the like are operated. A transmitter or the like that transmits to the unit is connected.

Then, the electronic control device C can calculate the traveling position of the forklift V based on each rotation history of the left and right traveling motors M, and the elevating table 22 is based on the operation history of the actuator A (that is, the elevating motor). (Therefore, the elevating position of the fork F) can be calculated. Further, particularly when the fork F is raised / lowered with respect to the carriage body 10 by the actuator A, the electronic control device C controls the operation of the actuator A based on the detection signals of the upper limit sensor 64 and the lower limit sensor 63 to control the operation of the fork F. Can be automatically stopped at a predetermined ascending / descending limit.

Further, the electronic control device C can be carried by an operation panel (for example, an operation panel provided on the trolley body 10), an operation panel provided at an appropriate position in a forklift V work place (that is, a warehouse, a factory, etc.), and / or a worker, which is not shown. Various setting operations can be arbitrarily performed based on the operation input for the remote controller, etc.). The setting operations include, for example, start / stop operation of the electronic control device C, setting operation of the travel route and travel mode of the forklift V, travel command operation and stop command operation of the forklift V, and pallets to be transported (hereinafter, pallets). The operation of selecting the target pallet (simply referred to as the target pallet) 71, the operation of setting the type of the target pallet 71, the setting of the final transfer position at which the target pallet 71 should be conveyed, and the like are included.

The operation unit is configured to be able to send and receive signals to and from the electronic control device C via a transceiver connected to the electronic control device C.

Thus, the electronic control device C independently controls the left and right traveling motors M so that the forklift V travels along the traveling route acquired by the route information acquisition unit Iz, and controls the left and right drive wheels W1 respectively. The forklift V can be driven independently in the forward and reverse directions, whereby the forklift V can be unmanned to travel close to, for example, the target pallet 71. In this case, for example, when the left and right drive wheels W1 are rotated forward (reverse) at the same speed, the forklift V goes straight forward (rear), and the right side (left side) with the left drive wheel W1 stopped. ), The forklift V turns to the left (right) around the ground contact point of the drive wheel W1 on the left side (right side) when the drive wheel W1 is rotated forward (reverse). Further, when the drive wheel W1 on the left side (right side) is reversed (forward rotation) and at the same time the drive wheel W1 on the right side (left side) is rotated forward (reverse rotation), the forklift V is rotated around the vertical axis passing through the centers of the left and right drive wheels W1. Rotates to the left (right).

Then, when the forklift V turns and rotates as described above, the driven wheel W2 that supports the fork F automatically follows the turning and rotation of the forklift V reasonably and smoothly.

Various variations are assumed for the route information acquisition unit Iz described above. For example, in the case of a control mode in which a central control system (not shown) installed in a workplace (that is, a warehouse, a factory, etc.) commands an electronic control device C to travel a travel route, a travel route command signal is received from the central control system. The receiver on the forklift V side, which outputs to the electronic control device C, constitutes the route information acquisition unit Iz. In this case, the central control system moves to the final transport location via the target pallet 71 based on, for example, the position information of the target pallet 71 selected and input by the operation unit and the final transport location thereof, and the current position of the forklift V. The travel route up to that point can be calculated by calculation. In addition, whether or not there are obstacles on the travel route is constantly checked by monitoring means such as a surveillance camera provided in the workplace or forklift V, and if there are obstacles on the travel route. In this case, the central control system may transmit a route correction command signal to the electronic control device C so that the traveling route of the forklift V can be corrected based on the signal.

Alternatively, when the travel route of the forklift V (that is, the transport route of the pallet) is fixed to one or more patterns, a route guide (for example, magnetic tape, guide light, etc.) is provided in the workplace corresponding to the travel route. A guide detection sensor capable of detecting this route guide may be provided on the forklift V side so that the route information detected by the guide detection sensor can be output to the electronic control device C. In this case, the guide detection sensor constitutes the route information acquisition unit Iz. Alternatively, the worker visually determines obstacles around the forklift V and the target pallet 71, and outputs a route command signal corresponding to the traveling route determined according to the situation to the electronic control device C by the operation unit. In this case, the receiver on the forklift V side, which receives the route command signal from the operation unit such as the remote controller and outputs it to the electronic control device C, constitutes the route information acquisition unit Iz.

Further, in the electronic control device C, after the forklift V traveling on the traveling route acquired by the route information acquisition unit Iz reaches near the target pallet 71, the position of the insertion portion (that is, the insertion hole h1) of the target pallet 71 and the position of the insertion hole h1 Even if the orientation is slightly different from the front side of the forklift V, the position information of the insertion part of the target pallet 71 acquired by the position information acquisition unit Ix (for example, camera 61, distance sensor 62) (for example, the difference output by the camera 61). The left and right traveling motors M can be controlled independently of each other based on the coordinate information that can be analyzed from the image data in the vicinity of the insertion portion and the distance information to the insertion portion output by the distance sensor 62. As a result, the forklift V can be moved and controlled so that the fork F is accurately inserted into the insertion hole h1 of the target pallet 71. That is, the electronic control device C has a function as a travel control device that controls the travel motor M based on the position information of the insertion portion acquired by the position information acquisition unit Ix.

By the way, as illustrated in FIG. 11, in the

pallets

71 and 72, the lower sides of the insertion holes h1 and h2 into which the forks F are inserted are closed by a plurality of

beams

71a and 72a, and the

beams

71a and 72a are closed. It is fixed to the main body frame of the

pallets

71 and 72, extends in the direction across the insertion holes h1 and h2 (that is, in the direction orthogonal to the fork insertion direction), and is arranged in parallel at intervals in the fork insertion direction. Orthogonal. The heights of the

beams

71a and 72a may differ depending on the types of the

pallets

71 and 72. For example, FIG. 11A exemplifies a beam 71a having a low height, and FIG. 11B exemplifies a beam 72a having a high height.

Therefore, when the forklift V arrives near the target pallet 72, the electronic control device C has a tall beam 72a or the like that may interfere with the tip of the fork F, particularly at the lower part of the insertion hole h2 of the target pallet 72. When there is an obstacle (for example, see FIG. 12A), the lower shape of the insertion hole h2 (that is, the beam 72a) acquired by the lower shape information acquisition unit Iy (for example, the camera 61) as image data. ), The elevating drive device 20 is controlled to ascend and displace the fork F by a predetermined ascending amount (that is, an amount that can avoid collision and riding, which will be described later) as shown in FIG. 12 (b). After that, the fork F is inserted into the insertion hole h2 of the target pallet 72. As a result, it is effective before the tip of the fork F collides with, for example, a steep slope of the beam 72a or a small step existing in the middle of the slope (see the solid line and the chain line in FIG. 12) or rides on the beam 72a. Can be avoided. That is, the electronic control device C also has a function as an elevating control device that controls the elevating drive device 20 based on the lower shape acquired by the lower shape information acquisition unit Iy.

In the present embodiment, the lower shape information acquisition unit Iy uses a camera 61 capable of outputting the lower shapes of the insertion holes h1 and h2 as image data, but the lower shapes of the insertion holes h1 and h2 are illustrated. Any technical means other than the camera 61 can be the lower shape information acquisition unit Iy. For example, if the types of the

target pallets

71 and 72 are specified, it is possible to acquire morphological information including the height of the lower shapes (obstacles such as

beams

71a and 72a) of the insertion holes h1 and h2 corresponding to the types. Therefore, for example, by setting and inputting the types of the

target pallets

71 and 72 in the operation unit, the types (thus, lower shape information of the insertion holes h1 and h2) can be output to the electronic control device C. .. In this case, the operation unit provided on the forklift V is the lower shape information acquisition unit Iy. Further, when the types of the

target pallets

71 and 72 are set and input in the work place and the operation unit provided in the remote controller, the receiver that receives the set type of the pallet and outputs it to the electronic control device C It becomes the lower shape information acquisition unit Iy.

Further, regardless of which of the above-mentioned lower shape information acquisition units Iy is used, the elevating drive device 20 is controlled and the fork is controlled based on the shape information of the lower shape (obstacles such as the beam 72a) of the insertion hole h2 acquired by the lower shape information acquisition unit Iy. The timing at which F is moved upward and displaced in advance can be automatically set based on, for example, the detection result of the distance sensor 62 used as the position information acquisition unit Ix. For example, when the distance detected by the distance sensor 62 reaches a predetermined value, the electronic control device C determines that the tip of the fork F and the insertion hole h2 are sufficiently close to each other, and the elevating drive device 20 determines that the fork F is sufficiently close. Is started to rise, and the amount of rise of the fork F at that time is set according to the degree of upward protrusion of the lower shape (obstacle such as the beam 72a) of the insertion hole h2.

Next, the operation of the above embodiment will be described.

When the target pallet 71 to be transported next by the forklift V and the final transport location to be transported are determined in the work place (for example, warehouse, factory, etc.), these information are input to the operation unit and then the operation is input. A transport command operation is performed in the operation unit. As a result, the electronic control device C independently controls the left and right traveling motors M so that the forklift V travels along the traveling route acquired by the route information acquisition unit Iz, and controls the left and right drive wheels W1 respectively. By driving independently, the forklift V is driven unmanned to the vicinity of the target pallet 71.

Then, when the forklift V reaches the vicinity of the target pallet 71, the position and orientation of the insertion portion (that is, the insertion hole h1) of the target pallet 71 is slightly deviated from the front side of the forklift V, particularly the fork F. There is. In this case, the electronic control device C eliminates the above deviation based on the information on the insertion position of the target pallet 71 acquired by the position information acquisition unit Ix (for example, the camera 61 and the distance sensor 62), and the fork F is the target pallet. The left and right traveling motors M are independently controlled to move and control the forklift V so that the forklift V is accurately inserted into the insertion hole h1 of 71. As a result, the fork F can be reliably inserted into the insertion hole h1 of the target pallet 71.

By the way, as illustrated in FIG. 11B, in the specific type of pallet 72, an obstacle such as a tall beam 72a that may interfere with the tip of the fork F is formed below the insertion hole h2 of the pallet 72. May exist. In this case, in the electronic control device C, after the forklift V arrives near the target pallet 72, the lower shape of the insertion hole h2 (the beam 72a) acquired by the lower shape information acquisition unit Iy (for example, the camera 61) as image data. The fork F is moved up and displaced by a predetermined amount in advance by controlling the elevating drive device 20 based on the morphological information of (obstacles such as). As a result, it is possible to prevent the tip of the fork F from colliding with or riding on an obstacle such as a beam 72a below the insertion hole h2 of the specific type of pallet 72.

Thus, when the insertion of the fork F into the insertion holes h1 and h2 of the

target pallets

71 and 72 is completed as described above, the electronic control device C operates the actuator A of the elevating drive device 20 to operate the elevating table. By raising 22 (hence, fork F) to the ascending limit defined by the upper limit sensor 64, the

target pallets

71 and 72 are lifted by a predetermined amount by the fork F.

After that, the electronic control device C causes the forklift V to travel to the final transport location with the

target pallets

71 and 72 lifted by the fork F, and after reaching the forklift V, operates the actuator A of the elevating drive device 20 to elevate and elevate. The base 22 (hence, the fork F) is lowered to the lowering limit defined by the lower limit sensor 63, and the

target pallets

71 and 72 are placed on the road surface E. After that, the fork F is slightly lowered and pulled out from the insertion holes h1 and h2 of the pallet 71, and then the forklift V is driven to the standby place in preparation for the next transfer work.

As described above, the forklift V of the present embodiment is a pair of traveling motors M capable of rotating and driving the left and right drive wheels W1 and the left and right drive wheels W1 which are non-steerably attached to the bogie body 10. The left and right forks F that extend from the fork base Fb and can mount and support the

pallets

71 and 72 as the transported object, the elevating drive device 20 that raises and lowers the fork base Fb with respect to the bogie body 10, and the left and right forks F. Left and right driven wheels W2 that are freely steerable via the support base 35, and elevating links that raise and lower the left and right forks F with the driven wheels W2 as fulcrums in conjunction with the elevating displacement of the fork base Fb with respect to the bogie body 10. It is provided with a mechanism 30.

As a result, the left and right drive wheels W1 can rotate the forklift V by rotating both drive wheels W1 independently on the left and right by a pair of traveling motors M even if they are non-steerably attached to the bogie body 10. Can be done. Therefore, it is not necessary to interpose a steering mechanism or a turning mechanism between the left and right drive wheels W1 and the bogie body 10, and the structure is simplified, and the weight of the forklift V can be reduced and the cost can be reduced. Further, the effect that the forklift V can be turned directly (and therefore accurately) without a turning mechanism and the effect that the driven wheel W2 that can be steered with respect to each fork F can reasonably follow the turning of the forklift V and turn. Together with this, the forklift V can be moved and swiveled smoothly and accurately to the

target pallets

71 and 72, so the fork F can be accurately aligned with the insertion holes h1 and h2 of the

target pallets

71 and 72. Therefore, work efficiency can be improved.

Further, in the present embodiment, a posture holding means (parallel link mechanism PL in the first embodiment) for keeping the mounting posture of the support base 35 with respect to the fork F constant so that the driven wheel W2 can always steer around the vertical axis is provided. Therefore, the driven wheel W2 is attached to the fork F via the support base 35 in a constant posture, and the driven wheel W2 can always be smoothly steered to turn the forklift V regardless of the elevating position of the fork F. ..

In this case, in particular, the elevating link mechanism 30 of the first embodiment is a connecting link paired with a relay link L3 that moves substantially along the longitudinal direction of the fork F in conjunction with the elevating displacement of the fork base Fb with respect to the trolley body 10. L4 and L5 are configured by pivotally connecting the fork F and the support base 35, and are provided with a parallel link mechanism PL that raises and lowers the support base 35 in a constant mounting posture in conjunction with the relay link L3. As a result, a part of the elevating link mechanism 30 (parallel link mechanism PL) is also used as the posture holding means, and the structure is simplified accordingly, which can contribute to cost reduction.

Further, in the present embodiment, the forklift V is provided based on the position information acquisition unit Ix capable of acquiring the position information of the insertion portions of the

pallets

71 and 72 and the position information of the insertion portion acquired by the position information acquisition unit Ix. Since it is provided with an electronic control device C as a travel control device that controls the left and right travel motors M for movement control, the difference between the

target pallets

71 and 72 when the forklift V reaches near the

target pallets

71 and 72. Even if the position and orientation of the insertion part (that is, the insertion holes h1 and h2) are slightly deviated, the electronic control device C controls the traveling motor M based on the position information of the insertion part to move the forklift V. By turning the fork F, the fork F can be accurately and accurately inserted into the insertion holes h1 and h2.

Further, in the present embodiment, the lower shape information acquisition unit Iy capable of acquiring information on the lower shapes of the insertion holes h1 and h2 of the

target pallets

71 and 72 and the lower shape information acquired by the lower shape information acquisition unit Iy are used. An electronic control device C as an elevating control device for controlling the elevating drive device 20 (more specifically, the actuator A) based on the elevating drive device 20 is provided. Therefore, in a specific type of pallet 72, if there is an obstacle such as a tall beam 72a that may interfere with the tip of the fork F at the lower part of the insertion hole h2, the lower part shape (beam). The electronic control device C controls the elevating drive device 20 to raise and lower the fork F based on the morphological information of (obstacles such as 72a), so that the tip of the fork F collides with or rides on the beam 72a or the like. It can be effectively avoided before it happens.

Second embodiment

Further, FIG. 13 shows a second embodiment of the present invention. In the first embodiment, the parallel link mechanism PL, which is a part of the elevating link mechanism 30, is also used as a posture holding means for keeping the mounting posture of the support base 35 with respect to the fork F constant. In the posture holding means PL'of the embodiment, the parallel link mechanism PL as in the first embodiment is not used, and the following structure is adopted.

That is, the support base 35'is formed in a U-shaped cross section that is long in the front-rear direction and opens downward in order to support the pair of front and rear driven wheels W2 at intervals, and the support base 35 has a pair of front and rear driving wheels. The driven wheels W2 are supported so as to be steerable around the vertical axis. The support mechanism 40 for each of the driven wheels W2 is the same as that of a conventionally known universal caster, that is, has the same structure as the support mechanism 40 for the driven wheel W2 of the first embodiment.

Then, in the elevating link mechanism 30'of the second embodiment, an intermediate portion of a pair of left and right connecting links L6 whose one end is rotatably pivotally connected to the front end of the relay link L3 via a pivot P11 is provided. , The left and right wall portions of the fork F are pivotally connected to the left and right wall portions via the pivot axis P12 so as to be rotatable back and forth. Further, at the other end of the pair of left and right connecting links L6, the left and right wall portions of the support base 35'(more specifically, the portion between the driven wheels W2 arranged in the front-rear direction) can rotate via the pivot P13. It is pivotally connected to.

Thus, the support base 35'is connected to the fork F via a pair of left and right connecting links L6 without falling to the left and right, and is not tilted back and forth via a pair of driven wheels W2 arranged at intervals in the front and rear. Since it is grounded, the support base 35'is held in a constant posture that is always horizontal. Therefore, the pair of front and rear driven wheels W2, the support base 35'that supports both of the driven wheels W2 via the support mechanism 40, and the pair of left and right connecting links L6 cooperate with each other to form the second embodiment. The posture holding means PL'is configured.

By the way, as shown in FIG. 13A, when the fork F is in the descending limit and the relay link L3 is in the retracting limit, the connecting link L6 interlocked and connected to the relay link L3 via the pivot P11 is prone. In the inverted position, the support base 35'(and therefore the driven wheel W2) is held in the standby position closest to the upper wall of the fork F, which puts the fork F in the lowest position, i.e. the lower limit position.

Then, from this state, the fork substrate Fb is displaced ascending by the elevating drive device 20, and when the relay link L3 is moved and displaced forward while slightly tilting in conjunction with this, it is interlocked and connected to the relay link L3 via the pivot P11. The left and right connecting links L6 stand up and rotate downward around the pivot P12 with respect to the fork F, so that the support base 35'(therefore, each turning axis forming the vertical of the front and rear driven wheels W2) is horizontal and constant. While maintaining the posture, it moves downward to an overhang position separated downward from the fork F. As a result, the fork F can be displaced with respect to the road surface E with the driven wheel W2 as a fulcrum to the ascending limit shown in FIG. 13B, and the pallet 71 can be lifted.

Since the other structures of the second embodiment are the same as those of the first embodiment, each component of the second embodiment is given the same reference code as the corresponding component of the first embodiment. , Further description is omitted.

Therefore, even in the second embodiment, basically the same action and effect as in the first embodiment can be achieved.

Although the examples of the present invention have been described above, the present invention is not limited thereto, and various design changes can be made without departing from the gist thereof.

For example, in the above-described embodiment, the transported objects to be transported by the forklift V as a transport vehicle are the

pallets

71 and 72 for loading articles, but even if the transported objects are other than the pallets, for example, the fork If the transported object has an insertion portion (for example, an insertion hole, a leg with an open bottom surface) that can be placed on the F or can be inserted by the fork F at the lower part, the transport vehicle according to the present invention can be transported. Be the target.

Further, in the above embodiment, the

pallets

71 and 72 as the transported object are provided with the insertion holes h1 and h2, and the fork F is inserted into the insertion holes h1 and h2. When the fork F is placed and supported via the support frame (that is, a part of the bottom surface of the transported object is lifted from the road surface E), the fork F is placed in the gap between the bottom surface of the transported object and the road surface E. By inserting the object, the bottom portion of the object to be conveyed may be directly placed and supported on the fork F for transportation.

Further, in the above embodiment, in order to guide the fork F up and down with respect to the bogie body 10, the fork F can be moved up and down and rotated between the bogie body 10 and the fork F via a pair of up and down first and second elevating links L1 and L2 (that is,). An example is shown in which the elevating locus of the fork F is pivotally connected in an arc shape), but the fork F is moved up and down with respect to the bogie body 10 by using a vertically sliding guide support mechanism provided between the bogie body 10 and the fork F. It may be guided and supported so as to be slidable (that is, the elevating locus of the fork F is linear).

Further, in the above embodiment, a camera 61 is used as the position information acquisition unit Ix and the lower shape information acquisition unit Iy, but a technique capable of outputting image data of the insertion portion (for example, insertion holes h1 and h2). If it is a means (for example, a laser radar or the like), it may be a position information acquisition unit Ix or a lower shape information acquisition unit Iy other than the camera 61.

Claims

A pair of traveling motors capable of rotating and driving the fulcrum body (10), the left and right drive wheels (W1) that are non-steerably attached to the fulcrum body (10), and the left and right drive wheels (W1) independently of each other. (M), left and right forks (F) extending from the fork base (Fb) and capable of mounting and supporting the conveyed objects (71, 72), and the fork base (Fb) with respect to the carriage body (10). An elevating drive device (20) for elevating and lowering, left and right driven wheels (W2) that are rotatably attached to the left and right forks (F) via support bases (35, 35'), and the trolley body (10). ), The left and right forks (F) are moved up and down with the driven wheel (W2) as a fulcrum in conjunction with the elevating and lowering displacement of the fork base (Fb). Transport vehicle.
Posture holding means (PL, PL') that keeps the mounting posture of the support base (35, 35') with respect to the fork (F) constant so that the driven wheel (W2) can always steer around the vertical axis. The transport vehicle according to claim 1, wherein the vehicle has.
The elevating link mechanism (30) is a connecting link (L4, L5) paired with a relay link (L3) that moves substantially along the longitudinal direction of the fork (F) in conjunction with the elevating displacement. A parallel link configured by pivotally connecting (F) and the support base (35) and raising and lowering the support base (35) in the constant mounting posture in conjunction with the movement of the relay link (L3). Equipped with a mechanism (PL)
The transport vehicle according to claim 2, wherein the parallel link mechanism (PL) is also used as the posture holding means.
The position information acquisition unit (Ix) capable of acquiring the position information of the insertion portion of the transported object (71, 72) into which the fork (F) is inserted and the difference acquired by the position information acquisition unit (Ix). The invention according to any one of claims 1 to 3, wherein the traveling control device (C) for controlling the pair of traveling motors (M) based on the position information of the embedded portion is provided. Transport vehicle.
A lower shape information acquisition unit (Iy) capable of acquiring information on the lower shape of the insertion holes (h1, h2) into which the fork (F) is inserted, and an acquisition of the lower shape information of the conveyed object (71, 72). Any one of claims 1 to 4, characterized in that the elevating control device (C) for controlling the elevating drive device (20) based on the information on the lower shape acquired by the unit (Iy) is provided. The transport vehicle described in the section.