JP6600183B2 - Cargo handling vehicle - Google Patents

Description

  The present invention relates to a cargo handling vehicle capable of loading and unloading containers on a chassis between the chassis and the ground.

  The cargo handling vehicle includes a lift arm whose rear end is pivotally supported on a chassis on which a container can be mounted, and a lift operation unit for raising and lowering the lift arm. A hook arm that has a hook that can be connected to the front end of the lift arm so that the posture can be changed by tilting the hook in a direction approaching the pivot center of the lift arm from the running posture, and tilting the hook arm And a hook operating unit.

  In the cargo handling vehicle configured as described above, when a container is loaded on a chassis, first, the hook operation unit changes the posture to a tilt position in which the hook arm is tilted rearward. In this posture of the hook arm, the lift operation unit rotates the lift arm forward, so that the hook is engaged with the container and lifted, and the container is placed on the chassis (Patent Document 1). ).

Japanese Patent Laid-Open No. 10-1000077 (see FIG. 7)

  By the way, the distance between the rotation center of the container and the hook is limited to such a distance that the container lifted by the lift arm does not interfere with the chassis. When the distance is long, the moment (torque) around the rotation center of the lift arm when the container is lifted increases. For this reason, when the weight of the container increases, the container cannot be lifted and loaded.

  Then, an object of this invention is to provide the cargo handling vehicle which can be loaded even if it is a heavy container.

A cargo handling vehicle according to the present invention includes a lift arm whose rear end is pivotally supported so as to be able to move up and down in a front-rear direction on a chassis on which a container can be mounted, a lift operation unit that performs up-and-down rotation operation of the lift arm, and a container A hook arm connected to the front end of the lift arm so that the hook can be changed from a traveling posture to a fourth posture that is closest to the pivot center of the lift arm. , a cargo handling vehicle including a hook operation section for changing the posture of the hook arm, the lift operating portion in engagement with said hook arm hooks to the container that is on the earth rotates the lift arm in loading operation for placing the container on the undercarriage Te, the hook operating unit, the fourth group with respect to the rotation center of the hook be in the traveling attitude side the lift arm than posture Distance than apart reference position the hook arm so as to be located near the position to the attitude change operation closer to the rotation center, the lift operating portion while the hook near position, forward the lift arm After the container is lifted by engaging the hook with the container by rotating, and the container is lifted, the hook operating unit is configured such that the hook is farther from the rotation center than the reference position or the reference position. far the hook arm so as to position the operation to return to the running position side, the lift operating portion made is characterized in that operate to stow containers the lift arm by forward rotation.

According to the above configuration, when lifting the container on the ground, the hook is positioned at a reference position (the reference position is a position where the hook is closer to the travel posture side than the fourth posture where the hook is closest to the rotation center of the lift arm ). By positioning it at a position close to the rotation center, the moment (torque) around the rotation center of the lift arm can be reduced. After the container is lifted, the hook operation unit moves the hook arm back to the running posture side so that the hook is at a reference position or a position farther from the rotation center than the reference position. Containers do not interfere with the chassis. Even if the hook arm is returned to the travel posture side in this way, the lift arm moves upward (the side where the lift arm rises) compared to when the container is lifted. (Torque) does not increase. Therefore, a heavy container can be lifted and loaded on the chassis so as not to interfere with the chassis.

  In the cargo handling vehicle according to the present invention, the hook operation unit may move the hook arm to the reference position or the far position until the front lower end of the container lifted at the near position is closest to the rear end of the chassis. You may return.

  According to the above configuration, the container is lifted so as not to interfere with the chassis by returning the hook arm to the reference position or the far position until the front lower end of the container lifted at the near position is closest to the rear end of the chassis. In addition, the height of the trajectory drawn by the container when the container is moved while being lifted can be kept low.

  In the cargo handling vehicle of the present invention, the hook operation unit may change the posture of the hook arm to the near position side when the front lower end portion of the container is positioned above the chassis.

  According to the above configuration, when the front lower end portion of the container is positioned above the chassis, the locus drawn by the container when the hook operation unit moves the container while lifting the container by changing the posture of the hook arm to the near position side. Can be kept low.

  According to the present invention, when the container is lifted, the hook is positioned closer to the rotation center than the reference position, and after the lifting, the hook is moved to the reference position or a far position farther from the rotation center than the reference position. By this, even if it is a container with a heavy weight, the cargo handling vehicle which provides the cargo handling vehicle which can be loaded safely can be provided.

It is a whole side view of the cargo handling vehicle of this invention carrying a container. It is the whole cargo handling vehicle side view which tilted the hook arm to the rear side and moved the container back. It is the whole cargo handling vehicle side view which shows the state immediately before rotating a lift arm and dropping a container on the ground. It is the whole cargo handling vehicle side view which shows the state which rotated the lift arm and lowered the container on the ground. It is the top view which looked at the lift arm and the dump arm from the top. (A) is the side view which looked at the hook arm and lift arm with which a locking device is locked from the side, (b) is the bottom view which abbreviate | omitted partially seeing (a) from the bottom. It is an enlarged view of the principal part of FIG.6 (b). 6A is a side view showing a state in which the lock arm is unlocked by tilting the hook arm of FIG. 6A backward by a predetermined angle, and FIG. 6B is a bottom view of the state where FIG. It is. It is an enlarged view of the principal part of FIG.8 (b). (A) is the sectional view on the AA line in FIG. 6 (a), (b) is the sectional view on the BB line in FIG. 6 (a), (c) is the sectional view on the CC line in FIG. 6 (a). It is. It is a side view of the rear part of the cargo handling vehicle which shows the state which engaged the hook of the hook arm with the engaging part of the container on the ground. It is a side view of the rear part of a cargo handling vehicle which shows the state which lifted the container in the state engaged with the engaging part of the container on the ground on the hook of the hook arm, and showed the state which approached the rear-end part of the chassis. It is a side view of the rear part of the cargo handling vehicle which shows the state which returned the hook arm to the running posture side and further lifted the container. It is a side view of the rear part of the cargo handling vehicle which shows the state which rotated the lift arm further than FIG. It is a side view of the rear part of the cargo handling vehicle which shows the state which rotated the lift arm further than FIG. (A)-(e) is explanatory drawing which shows transition of the angle of a hook arm and a lift arm until it drops a container on the ground. (A)-(f) is explanatory drawing which shows transition of the angle of a hook arm and a lift arm until it mounts a ground container on a cargo handling frame.

  Hereinafter, a cargo handling vehicle according to an embodiment of the present invention will be described. As shown in FIG. 1, the cargo handling vehicle V has a cab Ca mounted in front of the chassis F and a cargo handling frame 1 mounted in the rear of the chassis F. As shown in FIG. 5, the cargo handling frame 1 includes a pair of left and right vertical frames 1A and 1A that are long in the front-rear direction, and a horizontal frame 1B that connects intermediate portions of the vertical frames 1A and 1A in the left-right direction. . A container Ct is mounted on the cargo handling frame 1. An outrigger D is provided at the rear of the chassis F. The outrigger D is used to stabilize the cargo handling vehicle V on the ground GR when the container Ct is loaded or unloaded, or when dumped.

  As shown in FIGS. 1 to 5, a pair of left and right guide rollers 2, 2 projecting outward in the left-right direction are rotatably attached to the rear end portion of the cargo handling frame 1. These guide rollers 2 and 2 move and guide the container Ct while rotating when the container Ct on the cargo handling frame 1 is lowered onto the ground or when the container Ct is mounted on the cargo handling frame 1 from the ground.

  Further, as shown in FIG. 5, the rear end portion of the dump arm 3 is pivotally supported at the rear end portion of the cargo handling frame 1 so that the dump arm 3 can tilt around the horizontal axis 3T. ing. The dump arm 3 includes a pair of left and right vertical frames 3A, 3A that are long in the front-rear direction, an intermediate horizontal frame 3B that connects intermediate portions of the vertical frames 3A, 3A in the left-right direction, and front ends of the vertical frames 3A, 3A. And a front end horizontal frame 3C to be connected. A rotating shaft 3D is penetrated near the front side of the middle part of the vertical frames 3A, 3A, and the rear end of the lift arm 4 is attached to the rotating shaft 3D so as to be integrally rotatable. The lift arm 4 is positioned between the vertical frames 3A and 3A of the dump arm 3, and the rear end portion overlaps the front end portions of the vertical frames 3A and 3A of the dump arm 3 in the front-rear direction. Further, an intermediate portion of the lift arm 4 and a front end portion of the cargo handling frame 1 are connected by a pair of hydraulic lift cylinders 5 and 5. By operating the lift cylinders 5 and 5 to extend and contract, the lift arm 4 can be rotated around the rotation shaft 3D.

  As shown in FIGS. 6A and 8A, the base end portion of the substantially L-shaped hook arm 6 is attached to the front end portion of the lift arm 4 so as to be rotatable around the horizontal axis 7 in the left-right direction. The hook arm 6 is configured to be tiltable so that a hook 8 (to be described later) approaches the rotation axis 3D (rear side) that becomes the rotation center Z (see FIG. 11) of the lift arm 4. ing. A substantially C-shaped hook 8 that engages with the engaging portion 12 of the container Ct is provided at the upper end of the hook arm 6. A hydraulic hook cylinder 9 is connected between the intermediate portion of the hook arm 6 and the front end portion of the lift arm 4, and the hook arm 6 is shown in FIG. The rear side shown in FIG. 8A from the traveling posture, that is, the tilted posture in which the hook 8 is tilted by a predetermined angle in the direction approaching the rotation shaft 3D of the lift arm 4 (retracted from the traveling posture by a predetermined distance H in FIG. 8A). The posture can be changed to a posture (a second posture in which a hook 8 described later is closer to the rotation shaft 3D than the traveling posture).

  The lift cylinders 5, 5 constitute a lift operation part for operating the lift arm 4 to move up and down, and the hook cylinder 9 constitutes a hook operation part for tilting the hook arm 6.

  The container Ct is configured in a box shape having a plurality of traveling wheels 11 on the lower surface, and an engaging portion 12 that can be engaged with a hook 8 of a hook arm 6 described later is provided on the front side of the container Ct. On the rear side, an openable rear gate 13 is provided.

  As shown in FIGS. 6A and 6B to FIG. 9, the lift arm 4 undulates with respect to the dump arm 3 on the lower surface of the lift arm 4 so that the dump arm 3 and the lift arm 4 dump the container Ct. It is possible to switch between a locked state in which the movement is locked and an unlocked state in which the hook arm 6 and the lift arm 4 unload the container Ct or release the lock of the lifting and lowering rotation of the lift arm 4 with respect to the dump arm 3 to load the container Ct. The locking device 10 is provided.

  The locking device 10 is engaged with the pair of left and right locked portions 14 and 14 provided on the front end lateral frame 3C of the dump arm 3 and the locked portions 14 and 14 to lock the two arms 3 and 4. A pair of substantially L-shaped lock portions 15 and 15 that are pivotally supported around both sides of the lift arm 4 so as to be releasably pivotable about the horizontal axis Y1, and the lock portions 15 and 15 are locked portions 14. And an urging means 16 for urging the engaged state. The pair of left and right lock portions 15, 15 are connected by a bracket 17. The urging means 16 is composed of a pair of coil springs (only one is shown in FIG. 6A) provided between the lift arm 4 and the lock portions 15 and 15.

  The hook arm 6 and the locking device 10 are interlocked by the interlocking unit 18, and the locking device 10 is configured to be switched from the locked state to the unlocked state by tilting backward (changing the posture) of the hook arm 6.

  The interlocking unit 18 unlocks the locking device 10 during the rearward tilting (posture change) of the hook arm 6, and the unlocked state is released when the hook arm 6 tilts rearward (posture change) after unlocking. An unlocking part R1 to be held and an interlocking releasing part R2 for releasing the interlocking of the hook arm 6 and the locking device 10 when the hook arm 6 is unlocked and tilted to the rear side (posture change) are provided. Specifically, as shown in FIGS. 6A and 6B, the interlocking unit 18 includes a first push-pull rod 19 having one end connected to the bracket 17 on the locking device 10 side, and a hook arm. 6 is provided with a second push-pull rod 20 having one end connected to the side, and a lock release portion R1 and an interlock release portion R2 are provided between the first push-pull rod 19 and the second push-pull rod 20. ing.

  As shown in FIGS. 6B and 10C, one end of the first push-pull rod 19 on the locking device 10 side is provided with a connecting portion 19B having a bifurcated tip, and the bottom plate portion of the bracket 17 A vertical plate 17B protruding upward is provided on the upper surface of 17A. The bifurcated tip of the connecting portion 19B is sandwiched from the left and right directions into the vertical plate 17B, and in this state, a pin is formed in a hole (not shown) formed in the vertical plate 17B and a hole (not shown) formed in the connecting portion 19B. The vertical plate 17B is connected to the connecting portion 19B by preventing the tip of the pin P1 from coming off after passing through P1. The holes formed in the vertical plate 17B are formed as vertical holes that are long in the vertical direction, and the holes formed in the connecting portion 19B are formed as round holes that allow the pin P1 to pass therethrough.

  Further, as shown in FIGS. 6B and 10A, one end on the hook arm 6 side of the second push-pull rod 20 is provided with a connecting portion 20K having a bifurcated tip portion. On the upper surface of the bottom plate 6A that is bolted to the base end portion, there is provided a vertical plate 6B that extends obliquely upward and rearward. The bifurcated tip of the connecting portion 20K is sandwiched from the left and right directions in the vertical plate 6B, and in this state, a pin is formed in a hole (not shown) formed in the vertical plate 6B and a hole (not shown) formed in the connecting portion 20K. The vertical plate 6B is connected to the connecting portion 20K by preventing the tip of the pin P2 from coming off after passing through P2. The holes formed in the vertical plate 6B are formed as vertical holes that are long in the vertical direction, and the holes formed in the connecting portion 20K are formed as round holes that allow the pin P2 to pass therethrough.

  The first push / pull rod 19 is smoothly guided in the longitudinal direction of the lift arm 4 by a plurality of support members 22 attached to the lower surface of the lift arm 4. As shown in FIG. 10B, the support member 22 is sandwiched between a U-shaped support bracket 22A fixed to the lower surface of the lift arm 4 and a pair of downward plates 22a and 22a of the support bracket 22A. A pair of left and right half members 22B and 22B fixed by bolts 22M and nuts 22N are provided. Arc portions 22b and 22b that sandwich the first push-pull rod 19 (not shown in FIG. 10B) are formed on the opposing surfaces of the half members 22B and 22B. The second push / pull rod 20 includes a first rod 20A coupled to the hook arm 6 and a second rod 20B coupled to extend toward the lock device 10 via an operation unit 24 described later. Each of the first rod 20 </ b> A and the second rod 20 </ b> B is supported by the plurality of support members 22.

  The unlocking portion R1 is configured so that the locking device 10 is unlocked during the tilting (posture change) of the hook arm 6 to the rear side. Specifically, the unlocking portion R1 swings the swing link 23 as an operated portion connected to a pin 19P provided on the end member 19A at the other end of the first push / pull rod 19, and the swing link 23. The operation part 24 provided between the 1st rod 20A and the 2nd rod 20B which comprise the 2nd push-pull rod 20 in order to operate is provided.

  The swing link 23 has an elongated hole 23A for penetrating and connecting the pin 19P at one end, and the other end is pivotally supported on the lower surface of the lift arm 4 so as to be swingable about the vertical axis X1. A rotating member 25 having a claw portion 25 </ b> A that rotates integrally is provided on the upper surface of the base end portion that is the swing center side of the swing link 23. The operation part 24 is for releasing the engagement of the lock part 15 against the urging force of the urging means 16 during the rearward tilting (posture change) of the hook arm 6. Specifically, the operation unit 24 includes an abutting portion 26 that abuts on a claw portion 25 </ b> A of a rotating member 25 attached to the swing link 23 to swing the swing link 23. The contact portion 26 is formed by a cutout portion 26 </ b> K in which one side portion of the left and right side portions of the operation portion 24 is cut out. Then, the contact portion 26 comes into contact with the claw portion 25A of the rotating member 25 in the first posture in which the hook arm 6 is moved backward by a predetermined distance, and the swinging link 23 starts swinging. The first posture is shorter than the predetermined distance H of the second posture and is closer to the traveling posture than the second posture. The swing link 23 is swung by changing the posture from the first posture to the second posture in which the hook arm 6 is further moved backward by a predetermined distance. The position of the contact portion 26 with respect to the claw portion 25A is set so that the lock device 10 is switched to the unlocked state by the swing of the swing link 23. Accordingly, when the hook arm 6 tilts rearward, the contact portion 26 contacts the claw portion 25A of the rotating member 25 and swings the swing link 23. When the posture of the hook arm 6 is changed to the second posture, the second push-pull rod 20 is pulled away from the lock device 10 indicated by an arrow as shown in FIGS. 8B and 9. As a result, the swing link 23 is swung counterclockwise from FIGS. 6B and 7, whereby the first push-pull rod 19 is pulled toward the hook arm 6. As a result, the lock portions 15 and 15 are engaged and disengaged from the locked portions 14 and 14 to unlock the lock device 10 (see FIG. 8A). When the lock is released, the hook arm 6 is in the second posture shown in FIG.

  The interlocking unit 18 receives the operation force from the hook arm 6 to the locking unit 15 of the locking device 20 so as to maintain the locked state until the hook arm 6 is changed from the traveling posture to the rearward posture of a predetermined amount that is unlocked. , 15 is provided with a dead zone portion that does not transmit to. As shown in FIG. 7, the dead zone portion includes a gap E formed between the claw portion 25 </ b> A of the rotating member 25 and the contact portion 26 formed by the notch portion 26 </ b> K. By forming this gap E, the contact portion 26 can come into contact with the claw portion 25A of the rotating member 25 until the hook arm 6 is changed to the first posture (posture change amount smaller than the second posture). Absent. Then, when the hook arm 6 comes into contact with the claw portion 25A in the first posture of the hook arm 6 and then the posture of the hook arm 6 is changed to the second posture, the swing link 23 is swung and the lock device 10 is swung. Is switched to the unlocked state. Therefore, as shown in FIG. 13, the lift cylinder 5 is extended and the dump arm 3 and the lift arm 4 are rotated together with the lock portion 15 of the lock device 10 locked to the locked portion 14. In a state where the container Ct is dumped, for example, when the oil leakage occurs in the hook cylinder 9 and the hook arm 6 tilts rearward (changes the posture), the gap (dead zone) is Therefore, since the contact portion 26 does not contact the claw portion 25A of the rotating member 25 until the hook arm 6 is changed to the first posture, the lock portions 15 and 15 are maintained in the locked state, and the lock device There is an advantage that the ten lock portions 15 can be prevented from being unlocked from the locked portion 14.

  The interlock release unit R2 is an interchangeable unit that does not transmit the operation force from the operation unit 24 to the swing link 23 after the lock device 10 is unlocked between the operation unit 24 and the rotating member 25 of the swing link 23. It is composed of The interchangeable portion R2 includes a claw portion 25A of the rotating member 25 and a flat surface 27 extending from the contact portion 26 of the operation portion 24 toward the locking device 10 side. In other words, the rotating member 25 rotates and the claw portion 25A rides on the flat surface 27 of the operating unit 24 (see FIGS. 8B and 9), so that the rotating member can be operated even if the operating unit 24 is further pulled. 25 does not rotate and maintains the posture in which the claw portion 25 </ b> A is in contact with the flat surface 27, and constitutes a flexible portion R <b> 2 that does not transmit the operating force from the operating portion 24 to the swing link 23. Therefore, after the claw portion 25A rides on the flat surface 27 of the operation unit 24, the posture of the hook arm 6 is further rearwardly changed, so that the swing link 23 moves completely even if the operation unit 24 is further pulled. The position where the claw portion 25A is in contact with the flat surface 27 is maintained (the lock device is in the unlocked state). After the locking device 10 is unlocked by this interchangeable portion R2, the operating force from the operating portion 24 is not transmitted to the swing link 23, which is the operated portion, so that the locking portion 15, 15 does not move and unexpectedly comes into contact with other objects.

  Further, when the hook arm 6 is returned from the tilted position to the vertical position, the swing link 23 is forced to rotate clockwise by contacting the contact piece 23B of the swing link 23. A return operation unit 28 for swinging is provided. By providing the return operation part 28, even when the urging force of the coil spring 16 as the urging means is weak, the locking device 10 can be reliably locked. The return operation unit 28 includes two nuts screwed to the bolt, and the timing of contacting the contact piece 23B can be changed by changing the position of the nut with respect to the bolt.

  In a state where the hook 8 of the hook arm 6 is engaged with the engaging portion 12 of the container Ct on the ground, the lift cylinders 5 and 5 as the lift operation portion rotate the lift arm 4 to place the container Ct on the chassis F. Place and load. In the loading operation, the following control is performed. That is, the hook cylinder 9 is hooked so that the hook 8 is positioned closer to the rotation center Z (of the rotation shaft 3D) than the reference position where the hook 8 is separated from the rotation center of the lift arm 4 by a reference distance. The lift cylinder 9 lifts the container Ct by engaging the hook 8 with the container Ct by rotating the lift arm 4 forward while the arm 6 is tilted (posture change operation) and the hook 8 is in the close position. After the operation (see FIGS. 11 and 12) and lifting the container Ct, the hook cylinder 9 causes the hook 8 to be in the reference position (or a position farther away from the rotation center Z than the reference position). The lift cylinders 5 and 5 are loaded with the container Ct by rotating the lift arm 4 forward. The lift cylinders 5 and 5 and the hook cylinder 9 are driven and controlled by a control unit (not shown).

  Here, the reference position is a position where loading can be performed without interfering with the chassis F when the container Ct is loaded while the hook arm 6 is maintained in a predetermined posture. Specifically, the reference position is a posture (fourth posture) that is a posture change amount larger than the second posture from the second posture when the hook arm 6 in the traveling posture perpendicular to the lift arm 4 is unlocked. ) Can be arbitrarily set up to a posture (third posture) with a slightly smaller posture change amount. Further, the posture when the hook arm 6 is tilted by the hook cylinder 9 so as to be located at the near position is the fourth posture (an posture with a larger posture change amount than the third posture).

The reference position will be described with reference to FIG. First, the distance from the rotation center Z to the hook 8 is a, the distance from the rotation center Z to the rear end of the vehicle is b, the protruding distance of the container Ct when the container Ct is lifted is c, and the height of the container Ct is h. The maximum inclination angle of the container Ct is θ. At this time, if the relationship satisfying a> b + c is satisfied, the container Ct can be loaded without interfering with the chassis F. If the value a is set from the relationship, the reference position is obtained. Here, it is obtained by c = h × sin θ. In the present embodiment, when the hook 8 is positioned substantially directly above the rotation center Z (see FIG. 3), θ is 30 ° which is the maximum value, and therefore the maximum value of c is h × sin θ. Become. Further, the protruding distance c is defined as the protruding end of the container Ct, where the extended line extending downward from the lower end of the front end of the container Ct and the extended line extending forward from the front end of the lower end of the container Ct are defined as the protruding end of the container Ct.
In the present embodiment, b is obtained from the distance from the rotation center Z to the rear end of the rear bumper that protrudes most rearward of the vehicle, but b is the distance to the rear end of the vehicle at the same height as the lower end of the container front end, for example, the roller 2 It is good also as distance to. In addition, although a is slanted in the figure, the hook 8 moves in the front-rear direction as the lift arm 4 rotates, so that the value of a established by replacing a on the left side with a horizontal component in the above relationship. May be set.
FIG. 12 shows a state where there is a slight gap between b and c, but a> b in a state where there is no gap, that is, the lower end of the front end of the container Ct is in contact with the rear end of the vehicle. The value of a may be set from the relationship satisfying + c.

  A loading operation when the container Ct on the ground GR is mounted on the cargo handling frame 1 will be described.

  FIG. 11 shows a state immediately before the hook C of the hook arm 6 is engaged with the engaging portion 12 of the container Ct and the container Ct is lifted. In this engaged state, the rear end of the cargo handling vehicle V is positioned in front of the container Ct, and then the hook cylinder 9 is extended and the hook arm 6 is brought into the second posture as described above to lock. After the release, the piston rods 5A and 5A (only one is shown in FIG. 11) of the lift cylinders 5 and 5 are extended. As a result, the lift arm 4 is rotated and tilted backward (not shown, but the tilt is slightly larger than that in FIG. 11). Subsequently, the hook cylinder 9 is further extended to change the posture of the hook arm 6 to the fourth posture, thereby bringing the hook 8 into the close position. From this state, the piston rods 5A, 5A of the lift cylinders 5, 5 are shortened to engage the hook 8 of the hook arm 9 with the engaging portion 12 of the container Ct. At the time of this engagement, the cargo handling vehicle V may be moved forward and backward to adjust the front-rear position so as to be engaged reliably. After changing the posture of the hook arm 6 to the fourth posture, the piston rods 5A, 5A of the lift cylinders 5, 5 may be extended to start the rotation of the lift arm 4, or the lift arm 4 may be rotated. The posture of the hook arm 6 may be changed to the fourth posture.

  Subsequently, with the hook 8 in the close position and engaged with the engagement portion 12, the piston rods 5A and 5A of the lift cylinders 5 and 5 are shortened to rotate the lift arm 4 forward, thereby causing the container Ct to move forward. Lift up. At this time, the front lower end portion of the container Ct lifted at the near position moves to a position before the closest end to the rear end portion of the chassis F (see FIG. 12). When the container Ct is further lifted from the state of FIG. 12, the front lower end portion of the container Ct interferes with the rear end portion of the chassis F. Therefore, when the hook cylinder 9 is shortened, the hook arm 6 is moved to the third posture on the traveling posture side so that the hook 8 becomes the reference position (or may be a far position farther from the rotation center Z than the reference position). An operation of returning to the second posture (or any posture between the third posture and the second posture) may be performed (see FIG. 13).

  Continuing from the state of FIG. 13, the container Ct is further lifted by rotating the lift arm 4 forward (see FIGS. 14 and 15 further lifted from FIG. 14).

  As described above, when the container Ct on the ground GR is lifted, the moment (torque) around the rotation center Z is set by positioning the hook 8 closer to the rotation center Z of the lift arm 4 than the reference position. Can be reduced. After lifting the container Ct, the hook cylinder 9 returns the hook arm 6 to the traveling posture side so that the hook 8 is at a reference position or a far position farther from the rotation center Z than the reference position. Accordingly, the container Ct does not interfere with the chassis F when the container Ct is lifted and loaded. Even if the hook arm 6 is returned to the traveling posture side in this way, the lift arm 4 is moved upward (the side where the lift arm rises) compared to when the container Ct is lifted. The moment (torque) around the center Z does not increase. To explain this, as a first action, in FIG. 17A, an imaginary line from the rotation center Z to the hook 8 when the container Ct is lifted and the weight of the container Ct in the vertical downward direction applied to the hook 8 are reduced. In FIG. 17B, the virtual line from the rotation center Z to the hook 8 when the container Ct is slightly lifted and the weight of the container Ct in the vertical downward direction applied to the hook 8 is smaller than the angle α1 formed by the virtual line. Since the angle α2 formed with the imaginary line is a smaller angle (acute angle), the moment applied to the lift arm 4 is smaller in FIG. 17B than in FIG. Further, as a second action, as shown in FIG. 12, the lift arm 4 is rotated forward when the container Ct is lifted so that the angle formed by the lift cylinder 5 and the lift arm 4 approaches a vertical position. The moment in the direction in which the arm 4 is pushed forward (M in the figure) increases. Therefore, from these first and second actions, the heavy container Ct can be lifted so as not to interfere with the chassis and can be reliably loaded onto the chassis. Although the operation of returning the hook arm 6 to the traveling posture side (far position) is performed simultaneously with the forward rotation of the lift arm 4, the forward movement of the lift arm 4 is temporarily stopped and then the hook arm 6 is rotated to the far position. Alternatively, the lift arm 6 and the hook arm 4 may be alternately rotated so that the hook arm 6 is rotated and returned to the far position.

  Further, by returning the hook arm 6 to the reference position or the far position until the front lower end of the container Ct lifted at the near position is closest to the rear end of the chassis F (at the closest position shown in FIG. 12). The container Ct can be lifted so as not to interfere with the chassis F. When the front lower end of the container Ct is lifted above the chassis F (roller 2) (or when it is in an arbitrary position after being lifted), the hook arm 6 is again close to the rotation center Z of the lift arm 4 By moving to the position, the height of the locus drawn by the container Ct when the container Ct is moved while being lifted can be kept low.

  FIGS. 17A to 17F are diagrams showing the angle transition of the hook arm 6 and the lift arm 4 during the loading operation when the ground container Ct is mounted on the cargo handling frame 1. FIG. 17A shows a state immediately before the container Ct is lifted with the hook arm 6 in the fourth posture. FIG. 17B shows a state where the container Ct is slightly lifted and then the hook cylinder 9 is shortened to change the posture of the hook arm 6 from the fourth posture shown by the broken line to the third posture shown by the solid line. In FIG. 17C, after changing the posture, the lift cylinder 5 is further shortened to rotate the lift arm 4, and the elevation angle of the lift arm 4 (the tilt angle with respect to the horizontal when looking up) is 80%. A solid line indicates a state in which the hook cylinder 9 is extended to be in a fourth posture, which is the maximum angle tilted further rearward from the third posture indicated by the broken line when the angle is in the range of ˜90 °. FIG. 17D shows a state in which the hook arm 6 is returned to the second posture (solid posture) that is the position returned from the fourth posture, which is the maximum angle indicated by the broken line, to the traveling posture side. FIG. 17 (e) shows a state in which the lift arm 4 is further placed on the cargo handling frame 1 by further rotating the lift arm 4 from the state of FIG. 17 (d). FIG. 17 (f) shows a state where the hook cylinder 9 is shortened and the hook arm 6 is returned to the traveling posture (a state where traveling is possible). During the loading operation of the container Ct, the height of the locus drawn by the container Ct when the container Ct is moved while being lifted by the lift arm 4 can be suppressed as low as possible (between FIGS. 17C to 17D). (See the posture (angle) of the hook arm 6).

  Next, a lowering operation for lowering the container Ct on the cargo handling frame 1 of the cargo handling vehicle V to the ground will be described.

  The hook cylinder 9 is extended from the travelable state in which the container Ct is mounted on the cargo handling frame 1 of the cargo handling vehicle V shown in FIG. As a result, the hook arm 6 is tilted rearward (posture change) to change the posture to the second posture (see FIG. 2). With this change in posture, as described above, the first push-pull rod 19 is pulled by the lock release portion R1, and the lock device 10 is unlocked (see FIGS. 8A and 8B). At this time, the container Ct moves backward relative to the cargo handling vehicle V, and when the hook arm 6 changes its posture to the second posture, the container Ct dropping device that engages the container Ct and the dump arm 3 is used. (Not shown) is also released. When the lock device 10 is unlocked, the extension operation of the hook cylinder 9 is stopped, the extension operation of the lift cylinder 5 is started, the lift arm 4 is rotated, and the container Ct is lifted and moved backward. After a predetermined time (slight time) has elapsed since the extension operation of the lift cylinder 5 has started, the hook cylinder 9 is again extended and tilted to the maximum angle (in FIG. 8A, the hook arm 6 is moved to the second position). Although the posture is changed to the posture, the posture is changed to a direction approaching the rotation shaft 3D of the lift arm 4 by changing the posture to the fourth posture tilted further than this.

  When the elevation angle of the lift arm 4 (inclination angle with respect to the horizontal when looking up) becomes 80 ° to 90 ° (when the inclination angle becomes larger than that in FIG. 3), the hook cylinder 9 is shortened and operated. It returns to the 3rd attitude | position which is an attitude | position close | similar to the driving | running | working attitude | position side by predetermined distance. At this time, the posture of the hook 8 is changed in a direction away from the rotation shaft 3D of the lift arm 4.

  When the shortening operation of the hook cylinder 9 is completed, the container Ct is lowered to the ground while only the lift cylinder 5 is expanded and contracted, and the lowering operation of the container Ct is completed (see FIG. 4).

  FIGS. 16A to 16E are diagrams showing the transition of the angle between the hook arm 6 and the lift arm 4 when the container Ct is lowered. FIG. 16A shows the running posture (initial state) of the hook arm 6. FIG. 16B shows a state in which the hook arm 6 is changed in posture from the running posture to the second posture. In FIG. 16C, after a predetermined time from the start of the rotation of the lift arm 4, the hook arm 6 is moved from the second posture (shown by a broken line) to the fourth posture where the maximum angle shown by the solid line is further retracted. This shows a state in which the posture has been changed. FIG. 16D shows the hook arm 6 as a broken line by shortening the hook cylinder 9 when the elevation angle of the lift arm 4 (the inclination angle with respect to the horizontal when looking up) is 80 ° to 90 °. A state (solid line state) in which a third posture is returned by a predetermined distance from the maximum angle to the traveling posture side is shown. FIG. 16E shows the angle between the hook arm 6 and the lift arm 4 when the lift arm 6 is further rotated and the container Ct is lowered while the hook arm 6 remains at the angle shown in FIG. 16D. Yes.

  As described above, after the lift arm 4 is rotated and the container Ct is lifted, the lift arm 4 is rotated by changing the posture of the hook arm 6 to a large posture change amount (third posture or fourth posture). Since the distance from the center Z to the hook 8 can be shortened, the height of the locus drawn by the container Ct when the container Ct is moved while being lifted by the lift arm 4 can be suppressed as low as possible (FIGS. 16C to 16D). (See angle of hook arm 6 between)).

  1 to 4, the description has been given of the case where the lock device 10 is unlocked and the lift arm 4 is rotated to lower the container Ct onto the ground GR or to load the ground GR container Ct. When the lift cylinders 5 and 5 are extended and the dump arm 3 and the lift arm 4 are rotated together while the 15 is locked to the locked portion 14, the container Ct can be dumped. (Not shown).

  The present invention can be variously modified without departing from the spirit of the present invention. In addition, the specific configuration of each part is not limited to the above embodiment.

  In the above-described embodiment, the case where the posture change to the rear side of the hook arm 6 is performed by tilting the hook arm 6 to the rear side from the traveling posture, but the hook arm 6 is slid to the rear side from the traveling posture. It may be performed by making it. Similarly to the case of tilting, for example, the slide is also changed from the first posture to the third posture (or the second posture) according to the slide amount from the running posture (the distance at which the hook 8 is brought close to the rotation shaft 3D of the lift arm 4). 4 postures) (so that the slide amount increases toward the third posture (or the fourth posture) side).

  Further, in the above embodiment, when the elevation angle of the lift arm 4 (inclination angle with respect to the horizontal when looking up) becomes 80 ° to 90 °, the hook cylinder 9 is shortened and returned to the traveling posture side by a predetermined angle. Although the posture is changed to the third posture, the configuration may be such that the hook cylinder 9 is shortened and returned to the traveling posture side by a predetermined angle regardless of the elevation angle of the lift arm 4. It is not necessary to change the angle of the hook arm 6 while the lift arm 4 is rotating.

  Further, in the above embodiment, the lock release portion R1 is configured by the contact portion 26 that makes contact with the claw portion 25A of the rotating member 25 attached to the swing link 23 and swings the swing link 23, and releases the interlock. Although the portion R2 is composed of an accommodation portion that does not transmit the operation force from the operation portion 24 to the operated portion 23 after the lock device 10 is unlocked, the accommodation portion may be omitted. At this time, the lock device 10 moves in the release direction even after the lock device 10 is unlocked. However, since the lock device 10 holds the released state, the dump arm 3 is interlocked with the rotation of the lift arm 4. do not do. Further, the unlocking part R1 and the interlocking releasing part R2 are configured to include a meshing type or friction type clutch in the transmission part for transmitting the pulling force from the rod 20 on the hook arm 6 side to the rod 19 on the locking device 10 side. May be. In this case, a sensor that detects that the hook arm 6 is in a predetermined posture (a predetermined tilt angle or a predetermined slide position), a drive mechanism that engages and disengages the clutch, and a drive mechanism based on a detection signal from the sensor. It is preferable to implement with a control device that controls the driving of the motor.

  Moreover, in the said embodiment, although the hook operation part and the lift operation part were comprised from the hydraulic cylinder, you may comprise from an air cylinder, an expansion-contraction motor, etc.

  Moreover, in the said embodiment, although the dumping arm 3 was provided and the dumping arm 3 and the lift arm 4 were rotated together, the container handling vehicle which can be made into the state which dumped the container Ct was shown, The dumping arm 3 may be omitted, and a cargo handling vehicle that cannot dump the container Ct, that is, a cargo handling vehicle that can only load and unload the container may be used.

DESCRIPTION OF SYMBOLS 1 ... Cargo handling frame, 1A ... Vertical frame, 1B ... Horizontal frame, 2 ... Guide roller, 3 ... Dump arm, 3A ... Vertical frame, 3B ... Intermediate part horizontal frame, 3C ... Front end side frame, 3D ... Rotating shaft, 3T ... Horizontal axis, 4 ... Lift arm, 5 ... Lift cylinder (lift operation part), 5A ... Piston rod, 6 ... Hook arm, 7 ... Horizontal axis, 8 ... Hook, 9 ... Hook cylinder (hook operation part), 10 DESCRIPTION OF SYMBOLS ... Lock device, 11 ... Traveling wheel, 12 ... Engagement part, 13 ... Rear gate, 14 ... Locked part, 15 ... Lock part, 16 ... Energizing means (coil spring), 17 ... Bracket, 18 ... Interlocking part, 19 ... Rod, 19A ... End member, 19P ... Pin, 20 ... Rod, 20A ... Rod, 20B ... Rod, 22 ... Support member, 22A ... Support bracket, 22B ... Half member, 22M ... Bolt, 2 N: Nut, 22a ... Downward plate part, 22b ... Arc part, 23 ... Swing link (operated part), 23A ... Long hole, 24 ... Operation part, 25 ... Rotating member, 25A ... Claw part, 26 ... Contact part, 26K ... notch part, 27 ... flat surface, 28 ... operation part, 29 ... first control means, 30 ... second control means, 31 ... third control means, 32 ... fourth control means, Ca ... cab , Ct ... container, D ... outrigger, F ... chassis, GR ... ground, H ... predetermined distance, R1 ... lock release part, R2 ... interlocking release part (flexibility part), X1 ... vertical shaft core, X2, X3 ... center line , Y1 ... horizontal axis, V ... cargo handling vehicle, Z ... center of rotation, [theta], [alpha] 1, [alpha] 2 ... angle

Claims (3)

A lift arm whose rear end is pivotally supported so as to be able to undulate and rotate in a front-rear direction on a chassis on which a container can be mounted, a lift operation unit for operating the undulation of the lift arm, and a hook that can be attached to and detached from the container A hook arm connected to the front end of the lift arm so that the posture can be changed from a traveling posture to a fourth posture where the hook is closest to the pivot center of the lift arm, and the posture of the hook arm is changed. A cargo handling vehicle equipped with a hook operating unit,
In loading operations the container that is on the earth by the lift operating unit hook arm of the hook in engagement is rotated the lift arm to place the container on the chassis,
The hook operation unit is located closer to the rotation center than a reference position that is closer to the running posture than the fourth posture and the hook is separated from the rotation center of the lift arm by a reference distance. When the hook arm is operated to change the posture so that the hook is in the close position, the lift operating unit lifts the container by engaging the hook with the container by rotating the lift arm forward. After operating and lifting the container, the hook operation unit performs an operation of returning the hook arm to the traveling posture side so that the hook is located at a far position farther from the rotation center than the reference position or the reference position. And the said lift operation part operate | moves so that the said lift arm may be rotated forward and a container may be loaded , The cargo handling vehicle characterized by the above-mentioned .   2. The hook operation unit returns the hook arm to the reference position or the far position until the front lower end of the container lifted at the near position comes closest to the rear end of the chassis. Cargo handling vehicle as described in.   3. The cargo handling vehicle according to claim 1, wherein the hook operation unit changes a posture of the hook arm to a near position side when a front lower end portion of the container is positioned above the chassis.