JPS6011040Y2 - Electric motor switch opening/closing device in forklift hydraulic valve switching device - Google Patents

Description

[Detailed Description of the Invention] This invention relates to an opening/closing device for a motor switch in a hydraulic valve switching device for a forklift.

At the front end of the forklift, a mast is pivoted at its lower end by a support shaft, and can be tilted back and forth by a required angle by left and right double-movement tilt cylinders.

In addition, a cargo loading fork is attached to the mast so that it can move up and down, and is raised and lowered by a single-acting lift cylinder.

The operator's seat of the forklift main body is equipped with a tilt operating lever and a lift operating lever.

FIG. 1 shows the hydraulic circuit of a forklift.

A hydraulic pump 4, which sends hydraulic pressure from the oil tank 1 to the tilt cylinder 2 and the lift cylinder 3, is driven by an electric motor 5.

A circuit that supplies power from the power source 6 to the electric motor 5 is provided with a contactor 7 that is opened and closed by a motor control relay.

A manual switching valve 8 for tilt operation is provided in the hydraulic circuit between the pump 4 and the tilt cylinder 2, and a manual switching valve 9 for lift operation is provided in the hydraulic circuit between the pump 4 and the lift cylinder 3. It is arranged.

These switching valves 8 and 9 are both 6-point and 3-position valves.

An outgoing conduit 11 branched from a main column conduit 10 connected to the pump 4 is connected to the pressure oil port of the switching valve 8, and a return conduit 12 that returns to the tank 1 is connected to the return port of the valve 8.

A two-point/two-position solenoid valve 13 for temporary stop is disposed in the return pipe 12.

A reciprocating conduit 14 is connected between the cylinder port of the switching valve 8 and the left and right tilt cylinders 2.

Similarly, an outgoing conduit 15 branched from the main column conduit 10 is connected to the pressure oil port of the switching valve 9, and a return conduit 16 is connected to the return port of the open valve 9, all the way to the tank 1.

One of the cylinder ports of the switching valve 9 is closed,
The other port and the foot cylinder 3 are connected by a reciprocating conduit 17.

A return pipe 18 is connected from the oil outlet of the cylinder 3 to the tank 1.

Further, a bypass pipe 19 is disposed in the bypass ports of both the switching valves 8 and 9 so as to circulate from the pump 4 to the tank 1.

Is the switching valve 8 operated? By tilting the bar 20, the switching valves 9 are respectively switched by the operating lever 21.

When both switching valves 8, 9 assume neutral positions 8c, 9c, both passages are closed.

When the switching valve 8 is switched to the normal position 8a, the mast tilts forward, and when the switching valve 8 moves to the reverse position 8b, the mast tilts backward.

Further, when the switching valve 9 assumes the normal position 9a, the fork moves upward when the lowered hip is switched to the reverse position 9b.

The electric motor start switch 22 for tilt operation is activated by the operation lever 20.
3 are respectively turned on and off by the operation lever 21 in conjunction with switching of the switching valve 8.9.

When the switching valves 8 and 9 are in the neutral positions 8c and 9c, the switches 22 and 23 are in the off state, and the switching valve 8
, 9 are switched to other positions, switch 2
2 and 23 are respectively turned on and the electric motor 5 is started.

By the way, in the forklift mentioned above, two levers are provided to operate the tilt cylinder 2 and lift cylinder 3, and one switch is provided to open and close the contactor 7, but other levers are provided to operate the tilt cylinder 2 and lift cylinder 3. As attachments are added and the number of levers increases, the number of switches also increases accordingly.

Therefore, in order to open and close all the switches properly, it is necessary to adjust the distance between the microswitch roller 24 and the cam 25 attached to the lever individually for each switch as shown in Figure 2. This is troublesome, and additional wire harnesses for wiring for the switch must be added, complicating the device.

This idea was made in view of the above-mentioned circumstances; no matter how many valves there are, only one switch remains; therefore, the distance between the roller and the cam only needs to be adjusted once, and the wires are wired separately. The present invention provides an opening/closing device for a motor switch in a hydraulic valve switching device for a forklift, which is configured so that there is no need to attach a harness.

This invention will be explained below with reference to embodiments shown in the drawings.

In this embodiment, the upper and lower sides of FIG. 1 are respectively referred to as upper and lower sides.

In FIGS. 3 to 5, reference numeral 26 indicates a plurality of levers pivotally attached to a support shaft 27, 28 indicates a plurality of arms connected horizontally to each lower end of the lever 26, and 29 indicates each tip of the arm 28. A plurality of hydraulic switching valves are connected via a downward connecting rod 30, and 31 is a spool thereof.

Further, reference numeral 32 denotes a plurality of drive-side rotating pieces that are connected horizontally to the lower ends of the plurality of levers 26, and are located on the opposite side of the arm 28, and each tip has a semicircular shape when viewed from the horizontal direction. It's rolled up.

Reference numerals 33 and 34 designate a pair of rotatable horizontal shafts that are arranged slightly ahead of each tip of the driving-side rotating piece 32, and are vertically parallel to each other.

Reference numerals 35 and 36 indicate a pair of upper and lower driven rotating pieces that are attached to a pair of upper and lower horizontal shafts 33 and 34, respectively, facing the driving side rotating piece 32, and both of them are attached to the driving side rotating pieces at the tip portions 35 a and 36 a. It is designed to sandwich the moving piece 32 from above and below.

The tips of these rotating pieces 35 and 36 are also rounded to form a semicircle when viewed from the horizontal direction.

37 and 38 are pairs of driven side rotating pieces 35 and 36, respectively.
．． These rear end portions 35b,
A tension spring is attached to 36b, 39.40 is a pair of upper and lower substantially rectangular cams attached to each end of a pair of upper and lower horizontal shafts 33.34, and 41 is a micro switch 42 for opening and closing the contactor. It's a roller.

The upper cam 39 is formed with an arcuate notch 43 that faces the roller 41 diagonally from below, and the lower cam 40 is formed with an arcuate notch 44 that faces the roller 41 from diagonally above.

In the above configuration, the microswitch 42 is in an off state.

Now, when the lever 26 is tilted in the direction of the solid arrow A, the valve 29 is switched, and at the same time, the main drive side rotary valve 32 is switched.
The driven side rotating pieces 35 and 36 that sandwich this rotate in the directions of the solid line arrows, respectively.

As a result, the upper horizontal shaft 33 and the upper cam 39 fixed thereto rotate in the direction of the solid line arrow, and the upper cam 39
The notch 43 comes into contact with the roller 41 and the solid line arrow B
direction, the microswitch 42 is turned on.

Conversely, when the lever 26 is tilted in the direction of the dashed arrow C, the valve 29 is switched, and the driving side rotation piece 32 and the driven side rotation pieces 35 and 36, as well as the lower horizontal shaft 34 and the lower cam 40, are all moved. The lower cam 40 rotates in the direction of the dashed arrow.
The notch 44 comes into contact with the roller 41 and presses it down in the direction of the dashed arrow, and the switch 42 is turned on in the same way.

Furthermore, when two or more levers 26 are simultaneously tilted in the direction of the solid line arrow A or the broken line arrow C, the switch 42 is turned on by a similar operation.

FIGS. 6 and 7 show modified examples of the driving side rotating piece 32 and the driven side rotating pieces 35, 36.

In FIG. 6, in order to smoothly engage each rotating piece,
A roller 45 is attached to the tip of the driving side rotating piece 32.

In FIG. 7, spacing adjustment bolt nuts 46 are attached to the tips of the driven side rotating pieces 35, 36 so that the rotation angle can be adjusted.

As explained above, in this invention, a plurality of levers for switching the hydraulic switching valve 29 are provided with a driving side rotating piece connected to the lower end of each lever, and a portion slightly ahead of the tip of each driving side rotating piece. A pair of rotatable horizontal shafts are arranged above and below, and a pair of driven side rotating pieces are attached to each pair of upper and lower horizontal shafts so as to sandwich a plurality of driving side rotating pieces from above and below, respectively. A pair of upper and lower cams each having a predetermined shape are attached to one end of each pair of upper and lower horizontal shafts, and each of these cams has cutouts that face the microswitch roller at a predetermined interval from diagonally above and below. Therefore, if one or more of the switching valve operating levers are tilted to the right or left from the neutral position,
The cam rotates in either the forward or reverse direction via the driving side rotating piece, the driven side rotating piece, and the horizontal shaft, and the notch formed in the cam comes into contact with the microswitch roller and pushes it. , a microswitch is activated, so no matter how many operating levers there are, it is sufficient to install one microswitch.

Therefore, the distance between the roller and the cam of the microswitch only needs to be adjusted once, and since the adjustment is easy and fine adjustment is possible, the microswitch can be opened and closed appropriately.

Also, since there is no need to install a new switch, there is no need to add a wiring harness.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram of a forklift, Fig. 2 is a front view of a switch showing a conventional example, Figs. A sectional view along the ■-■ line, Fig. 4 is a partially cutaway plan view, Fig. 5 is a cross-sectional view of the
6 and 7 are sectional views corresponding to FIG. 3 showing a modified example. 26... Lever 29... Hydraulic switching valve, 32... Drive side rotating piece, 33.34...
・・Horizontal axis, 35° 36・・・・・Driven side rotating piece, 3
7, 38... tension spring, 39.40...
Cam, 41...Roller, 43, 44...
・Notch.

Claims (1)

[Scope of utility model registration request] A plurality of levers 26 for switching the hydraulic switching valve 29
A pair of rotatable horizontal shafts 33 and 34 are disposed at the lower end of each of the movable side rotating pieces 32, and a pair of rotatable horizontal shafts 33 and 34 are arranged slightly ahead of the tip of each of the movable side rotating pieces 32, respectively.
A plurality of driving side rotating pieces 32 are attached to a pair of upper and lower horizontal shafts 33 and 34.
A pair of upper and lower driven rotating pieces 35 and 36 are attached so as to sandwich the upper and lower sides, respectively, and a pair of upper and lower cams 39 of a predetermined shape are attached to each end of the pair of upper and lower horizontal shafts 33°34.
．． 40 is attached to the cams 39 and 40, and notches 43 and 44 are respectively formed at predetermined intervals on the roller 41 of the microswitch, facing diagonally from above and below. Switchgear.