JPS5839088B2 - Automatic door opening/closing device for dump trucks - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an automatic door opening/closing device for a dump truck that can be applied to side dump trucks, tri-turn dump trucks, and the like.

Hereinafter, an embodiment in which the device of the present invention is applied to a side dump truck will be explained with reference to the drawings. In FIG. 1, 1 is a vehicle frame (subframe), 2 is a cargo box mounted on the vehicle frame 1,
．． 3', 3" 3/// indicates a pair of removable hinges provided on each side between the vehicle frame 1 and the cargo box 2. Depending on the selection of these hinges, the cargo box can be moved to one side or the other. 2 can be dumped.

Since the hinge parts 3, 3', 3" 3/// are all the same, the structure of one hinge part 3 is shown in FIGS. 2 and 3.
To explain the figure, a lower hinge body 6 is formed at the side end of the support tube 4 that is fixed in place on the vehicle frame 1 and has an engagement recess 5 that opens upward. The upper hinge body 8 has a hinge pin 7 fixedly fixed thereto and engages with the engagement recess 5, and the hinge part 3 is pivotably supported by the lower hinge body 6 and engages with the hinge pin 7 of the upper hinge body 8. It consists of a locking pawl 9 that performs a switching operation to switch between a locked state and a detachable state, respectively, and an operating rod 10 is connected thereto so that the operation of this locking pawl 9 can be controlled from the driver's cab.

Next, the automatic sliding door opening/closing device, which is the main part of the present invention, will be explained with reference to FIG. 4. A pair of left and right torque shafts 11° and 12 extending in the front and back direction are rotatably supported at the bottom of the cargo box 2. Swing pieces 13 and 13' are vertically provided at both ends of one torque shaft 11, and each of these swing pieces 13
, 13' are provided on one side, and the locking pin 1 at the bottom of the fan door 14
5.15' and is connected via rods 17, 17' to a pair of front and rear hooks 16, 16, which close the sliding door 14.

Further, each swinging piece 18.18' is vertically provided at both ends of the other torque shaft 12 as described above, and each swinging piece 18.18' is provided on the other side, and similarly as described above, each swinging piece 18.18' is provided on the other side.
Rods 22, 22 are attached to a pair of front and rear hooks 21, 21' that engage with locking pins 20 and 20' to close the sliding door 19.
'It is connected via '.

A pair of left and right bell cranks 23 and 24 are swingably supported on both sides of the bottom of the cargo box 2 near the rear hinge portions 3 and 3'' described above, and one arm piece 23 constituting one bell crank 23. A roller 26 that rotates along a guide piece 25 fixed to the lower hinge 6 or the support tube 4 is pivotally supported at ', and an operating piece fixed to the torque shaft 11 is mounted on the other arm piece 23'' of the bell crank 23. 27 to rod 28
The swing of the bell crank 23 is controlled by the rod 28.
, operating piece 27, torque shaft 11, rocking piece 13, 13
', and the bell crank 2 via the rods 17, 17'.
The signal is transmitted to a pair of front and rear hooks 16.16' on the opposite side from 3, and the hooks 16.16' can be swung.

Further, one arm piece 24' constituting the other bell crank 24 pivotally supports a roller 26' that moves along the same guide piece 25', and the other arm piece 24'' of the bell crank 24 Similarly to the above, the bell crank 24 is connected to the actuating piece 27' fixed to the torque shaft 12 via the rod 28', and the swinging of the bell crank 24 is caused by the rond 28' actuating piece 27' as before.
, a pair of front and rear hooks 21.2 via the torque shaft 12, the swinging pieces 18, 18' and the rod 22.22'.
1' and swing the hooks 21 and 21'.

Furthermore, the pair of left and right bell cranks 23 and 24 have a restraining piece 29 formed with engagement recesses 29' and 30' at the lower end.
．． 30 are fixed to each other, and the engagement recesses 29', 30' of the restraining pieces 29.30 are supported by L-shaped support brackets 31.32 fixed to the lower hinge bodies 6", 6 or the support tube 4, and Hinge 8", 8 hinge pin 7", 7
When the restraining piece 30 and the engaging pin 34 are engaged with each other, the corresponding hook 2L21' is attached to the loading box 2.
Holds in a locked state regardless of tilting.

In addition, 35.35' is the left and right hook 21, 21' and 16
．． A spring energized toward the side that releases the engagement of 16';
Reference numerals 36 and 36' indicate spring cylinders interposed between the rods 28 and 28'.

Next, to explain the operation, first, the hinge part 3" on one side
3ttt are disengaged from the hinge pins 7//, pt/, and the engagement claws 9, 91 forming the other side hinge portions 3, 3' are removed from the hinge pins 7, 71. When the cargo box 2 is engaged and lifted in this state, the cargo box 2 can be dumped to the right side centering on the hinge parts 3 and 31, as shown in FIG.

By the way, during the operation of the dump truck, the restraining piece 30 of the right hinge part 3 remains engaged with the engagement pin 34, so that the hooks 21 and 21' on the rising side are held in place and the lifting The door 19 can be kept closed.

On the other hand, the restraining piece 29 of the left hinge portion 3'' rises and disengages from the engagement pin 33, so the bell crank 23 rotates clockwise in FIG. , the torque is transmitted to the pair of front and rear hooks 16.16' through the actuating piece 27, the swinging pieces 13, 13' of the torque shaft 11, and the rod 17, 1?', and rotates the hook 16.16 in the counterclockwise direction. Door 14 is opened.

Therefore, at the same time as the loading box 2 is tilted, the swing door 14 on the hinge center side
Since the cargo box 2 will be opened, the loaded items in the cargo box 2 will be discharged to the side.

Also, when the rising cargo box 2 is lowered, the arm piece 23/roller 26 at the tip of the left bell crank 23 in FIG.
Since the bell crank 23 comes into contact with the guide piece 25 and rolls along the guide piece 25, the bell crank 23 rotates in the counterclockwise direction opposite to the above-mentioned direction.
' is rotated clockwise to close the fan door 14 when the cargo box 2 is lowered.

Furthermore, when dumping to the side opposite to that shown in Figure 1, the locking claws 9°91.9 of each hinge part 3.
"If 9ttt is switched in the opposite direction, the left side fan door 19 can be automatically opened while the right side fan door 14 is closed, almost as described above.

As described above, the present invention has a structure of a hinge part in which a lower hinge body with an engagement recess is attached to the vehicle frame side, and an upper hinge body to which a hinge pin that engages with the engagement recess is fixed is attached to the cargo box side. A bell crank constituting an automatic sliding door opening/closing device is provided at the bottom of the cargo box near the hinge, and this bell crank has a support groove on the vehicle frame side, and is engaged with and disengaged from an engaging pin whose center is aligned with the hinge pin. By using a structure in which the restraining pieces are fixed, even if the fan door on the desired discharge side is opened, the other fan doors can be kept closed, so that the loaded items can be reliably discharged to the desired side. This is very effective for side dump trucks and three-turn dump trucks, where the dumping direction can be controlled from the driver's cab.

[Brief explanation of drawings]

Fig. 1 is a rear sectional view showing the main parts of the present invention, Fig. 2 is a front view of the hinge part, Fig. 3 is a sectional view taken along A-A IIJ of Fig. 2, and Fig. 4 is an automatic sliding door of the present invention. It is a perspective view showing an opening and closing device. In the figure, 1 is the vehicle frame, 2 is the cargo box, 3 is the hinge part, and 5
6 is a lower hinge body, 7 is a hinge pin, 8 is an upper hinge body, 23 and 24 are bell cranks, 26 is a roller, and 29 and 30 are restraining pieces.

Claims (1)

[Claims] 1. A lower hinge body provided on the vehicle frame side and forming an engagement recess, and an upper hinge body and a lower hinge body provided on the cargo box side to which a hinge pin that engages with the engagement recess of the lower hinge body is fixed. A dump truck is provided with a plurality of removable hinge parts each consisting of a locking pawl that engages with and disengages from a hinge pin, and allows a cargo box to be dumped in a desired direction by selecting the hinge parts. A pair of bell cranks are pivotally supported on both sides of the bottom of the cargo box adjacent to the bottom of the cargo box, and one of the arm pieces that make up the bell crank has a roller that rolls along a guide piece provided on the vehicle frame side. The other arm piece is pivotably supported on the bottom of the other side of the cargo box, and is connected via a rond to a hook that can close the sliding door, and the lower hinge body A pair of retaining pins are provided on the vehicle frame side adjacent to the lower hinge body so that the centers of the hinge pins engaged with the engaging recesses of the lower hinge body are aligned with each other, and furthermore, a pair of retaining pins are provided on the pair of bell cranks that can engage with the engaging pins. An automatic door opening/closing device for a dump truck, which is provided with a pair of restraint pieces each having a mating recess formed at the lower end.