JPS6136553Y2 - - Google Patents

Description

[Detailed Description of the Invention] The present invention relates to a fork moving device for a forklift that can move left and right two forks attached to a finger bar simultaneously or independently.

In a device that uses a drive device such as a hydraulic cylinder or a motor to move the fork from side to side, when the fork reaches its stroke end, the drive device is adversely affected by the sudden stop.
Particularly in the case of an electric motor, there is a risk of a burnout accident.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to provide a fork moving device for a forklift that can protect the drive device from the adverse effects caused by a sudden stop of the fork.

Embodiments of the present invention will be specifically described below with reference to the drawings. In a forklift equipped with a visibility-improving mast device in which one lift cylinder is placed behind each of the left and right masts 1, finger bars 3 are installed at the top and bottom of the front of a lift bracket 2 that is raised and lowered along the mast 1. The upper and lower finger bars 3 are fixed at appropriate intervals, and the upper and lower finger bars 3 are connected by tie plates 4 at both ends thereof. Left and right 2 placed on the front of finger bar 3
The book fork 5 is locked to the finger bar 3 via a hook 6 so as to be slidable in the left and right direction, and on the back side thereof, a nut 7 serving as a screwing member projects rearward from between the upper and lower finger bars 3. installed to do so.

On the rear surface of the finger bar 3, between the upper and lower finger bars 3, two left and right screw shafts 8, each screwed into the nut 7 of the fork 5, are arranged concentrically, and the outer ends of both screw shafts 8 are connected to the fin. On the tie plate 4 of Gerber 3, the inner end is finger bar 3.
They are each rotatably supported by a gear box 9 fixed to the center of the rear surface. Moreover, both the left and right screw shafts 8 are formed with right-handed threads. A driven bevel gear 10 is slidably fitted loosely into each end of both the screw shafts 8 extending inside the gearbox 9. They are connected and separated by an electromagnetic clutch 11, respectively. That is, the left and right electromagnetic clutches 11 each have a disk 12 fixed on the screw shaft 8 so as to face the back surface of the driven bevel gear 10 with an extremely small gap therebetween, and a disk 12 that is opposed to the disk 12. It consists of an electromagnet 13 fixed to the inner surface of the gearbox 9, and the driven bevel gear 10 is attached to and released from the disc 12 by the action of the electromagnet 13, thereby performing coupling and separation. Further, a hydraulic motor 14 for moving the fork is attached to the gearbox 9 with its axial direction perpendicular to the axial center of the screw shaft 8, and a drive bevel gear 15 fixed on the shaft of the hydraulic motor 14 is attached. The driven bevel gear 1
0 is always engaged.

Therefore, when the hydraulic motor 14 is rotated in the forward or reverse direction with both driven bevel gears 10 connected to the screw shafts 8 by the electromagnetic clutch 11, both the screw shafts 8 are rotated in opposite directions, and the two screw shafts 8 are rotated in opposite directions. fork 5
are simultaneously moved inward or outward via the nut 7, and the driven bevel gear 10 and the screw shaft 8
When only one of the forks 5 is connected to the fork 5, only the fork 5 on the connected side is moved in accordance with the direction of rotation of the screw shaft 8.

Further, in order to detect that the fork 5 has reached the stroke end, the upper finger bar 3
There are two limit switches, one at each end of the left and right sides, and two limit switches at an appropriate distance from each other in the center.
Limit switches LS1 to LS4 are installed, and these limit switches LS1 to LS4 are activated when the forks 5 reach the stroke end or just before that by corresponding docks 16 provided on the rear surfaces of the upper hooks 6 of both forks 5. It is becoming more and more like this.

Next, the operating system of the electromagnetic clutch 11 and the hydraulic motor 14 will be explained with reference to FIGS. 4 to 6. As shown in FIG. 4, the electromagnets 13 in the left and right electromagnetic clutches 11 are connected in parallel to the battery B, respectively. Between the left electromagnet 13 and the left clutch control limit switch LS5, an outer limit switch LS1 and an inner limit switch LS2 for detecting the left stroke end are interposed in parallel.
Also, between the right electromagnet 13 and the limit switch LS6 for controlling the right clutch, there is an inner limit switch LS6 for detecting the right stroke end.
3 and an outer limit switch LS4 are interposed in parallel. Note that the limit switches LS1 to LS4 for detecting each stroke end are all normally closed.

On the other hand, the hydraulic motor 14 is controlled to drive (rotation direction) and stop by a single 3-position control valve CV (hydraulic circuit not shown), and a clutch control valve CV. The limit switches LS5 and LS6 are also configured to be operated by the operating lever 17 of the control valve CV, and the details thereof will be explained below with reference to FIGS. 5 and 6.

Valve body 1 in control valve CV
8 is fixed to a front protector (not shown) in front of the driver's seat, and a spool 19 that is slidable in the axial direction with respect to the valve body 18 for switching the oil path has its protruding upper end attached to the square shaft portion 19a. The operating lever 17 is fitted into this square shaft portion 19a through a long hole 17a and connected with a pin 20. Further, a support ring 21 is fitted onto the upper surface of the valve body 18 so as to allow movement in the axial direction with respect to the spool 19, and is rotatably attached to the valve body 18. A base end portion of the operating lever 17 is connected by a pin 23 to a support piece 22 erected at an end portion of the lever 17 .

That is, the operating lever 17 can be tilted up and down with respect to the valve body 18 with the pin 23 as the center of rotation, that is, the spool can be moved to change the oil path, and the lever 17 can be rotated horizontally to select a limit switch for clutch control, which will be described later. is considered possible. Note that the rotation range of the operating lever 17 is determined by a stopper 24 protruding from the upper surface of the valve body 18 and a support ring 21.
It is regulated by a locking part 25 formed on the upper surface of the.

An operating piece 26 having a horizontal V-groove 26a at its tip is formed at the end of the operating lever 17 on the tilting fulcrum side, and two limit switches LS5 and LS6 for controlling the clutch are opposed to this operating piece 26. It is located. This double limit switch LS5, LS
6, the actuator 27 is fitted into the V-groove 26a of the operating piece 26 when the operating lever 17 is in the neutral state.
It is held in the OFF state, and the actuator 27 is tilted upward or downward via the operating piece 26 by moving the spool of the operating lever 17.
Switched to ON state. In addition, the operating lever 17
When the limit switches LS5 and LS6 are rotated horizontally, one of the actuators 27 of the limit switches LS5 and LS6 comes out of the V-groove 26a of the operating piece 26.

This embodiment is configured as described above,
The effect will be explained below.

[Fork and simultaneous movement]

When the operating lever 17 is operated upward or downward to switch the spool 19 of the control valve CV, the hydraulic motor 14 is rotated forward or reverse depending on the switching position, while both limit switches LS5 and LS6 for clutch control are rotated. When turned on, the left and right electromagnets 13 are energized, so both driven bevel gears 10 are coupled to the screw shaft 8. Therefore, both screw shafts 8 rotate in opposite directions to each other, and the left and right forks 5
In this case, when the fork 5 reaches the outer or inner stroke end, the dog 16 of the fork 5 activates the limit switch LS1 for detecting the stroke end.
~ Since it comes into contact with LS4 and turns it off, current to the left and right electromagnets 13 is cut off, and both electromagnetic clutches 11 are released. As a result, the power from the hydraulic motor 14 to the screw shaft 18 is cut off, and the movement of the fork 5 is stopped.

[Fork solo movement]

After removing the actuator 27 of one of the limit switches LS5, LS6 for clutch control from the V-groove 26a of the operating piece 26 by horizontally rotating the operating lever 17 to either the left or right, the fork is moved simultaneously. as well as control valve
If you move the CV spool 19, the operation piece 2
One limit switch LS engaged with 6
5. Only LS6 is turned on. Therefore, in this case, limit switch LS5 or
Only the electromagnet 13 on the LS6 side is energized, and the electromagnetic clutch 11 is coupled. Therefore, the screw shaft 8 on the clutch coupling side is rotated, and the fork 5 screwed thereon is moved outward or inward, and when the stroke end is reached, the relevant signal for detecting the stroke end is activated as described above. The limit switches LS1 to LS4 are turned off to cut off the current to the electromagnet 13, so the electromagnetic clutch 11 is released. That is, the movement of the fork 5 is stopped.

Then, perform such operations on the fork 5 on the opposite side.
The left and right forks 5 can be moved to either the left or right side by performing the above steps, and the width of the movement can be adjusted as appropriate by operating the operating lever 17 before reaching the stroke end. It is possible to do so.

Therefore, in the embodiment, when the fork 5 reaches the stroke end, the left and right electromagnetic clutches 11 are released individually to cut off power transmission from the hydraulic motor 14 to the screw shaft 8 and stop the fork 5. This is convenient when returning the fork 5 that has shifted to the left or right as a result of the above-described single fork movement operation, that is, when performing a simultaneous movement operation. That is, when the forks are moved simultaneously, even if one of the forks 5 reaches the stroke end first, as long as the operating lever 17 is continued, the other fork 5 can be continuously moved to the stroke end.

Although this embodiment has been described using the hydraulic motor 14, an electric motor may be used instead.

As described in detail above, the present invention is a fork moving device that can move the fork to the left and right simultaneously or independently using a hydraulic motor or an electric motor as a drive source, which detects when the fork reaches the stroke end. By then releasing the left and right electromagnetic clutches, the power transmission of the motor to the screw shaft is cut off, so the fork can be stopped quietly at the end of its stroke without any impact, and the motor is not overloaded. It is possible to prevent the load from acting on it and extend its life.

Moreover, this invention allows the left and right electromagnetic clutches to be released individually when the forks reach the end of their stroke, so as long as the operating lever continues to move the forks simultaneously, the left and right forks can be moved to the end of their stroke. This is extremely effective when returning a fork that has shifted to either the left or right side to its original position, that is, to a bilaterally symmetrical position, by performing an independent movement operation of the fork.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention; Fig. 1 is a perspective view of a fork moving device, Fig. 2 is a side sectional view, Fig. 3 is a plan view, and Fig. 4 is a diagram showing an electromagnet control device for an electromagnetic clutch. FIG. 5 is a side view showing the control valve and limit switch operating means, and FIG. 6 is a plan view. 3...finger bar, 5...fork, 8...
...Spiral shaft, 10 ... Driven bevel gear, 11 ... Electromagnetic clutch, 14 ... Hydraulic motor, 15 ... Drive bevel gear, 16 ... Operation lever, CV ... Control valve, LS1 to LS4 ... Stroke end Detection limit switch, LS5, IS6... Limit switch for clutch control.

Claims (1)

[Scope of utility model registration request] Two left and right screw shafts that are screwed into the threaded member provided on the fork side and twisted in the same direction are installed concentrically and aligned on the rear surface of the finger bar, and each screw shaft is attached to the opposite end of each screw shaft. A driven bevel gear is attached via an operable electromagnetic clutch, and a driving bevel gear driven by a motor attached to the rear surface of the finger bar is meshed with both driven bevel gears, and furthermore, both the left and right ends of the finger bar are connected to each other. Detection means are installed in the upper and lower center sections to detect when the left and right forks have reached their stroke ends and command the release of the left and right electromagnetic clutches. A fork moving device for fork cliffs that is configured to control and individually cut off the power transmitted from the motor to the left and right screw shafts.