JPS6114021B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention improves vehicle stability during cargo handling and civil engineering work in industrial vehicles such as side forklifts that use hydraulic pressure to operate a torque converter clutch to switch the vehicle between forward, neutral, and reverse. This invention relates to a safety device that prevents a vehicle from starting when outriggers installed for the purpose of safety are lowered.

In general, in industrial vehicles, when performing cargo handling work, civil engineering work, etc., in order to prevent the vehicle from tilting or falling due to unbalanced loads acting on the vehicle, The vehicle is stabilized by lowering the outriggers fixed on each side and bringing their lower ends into contact with the ground. However, if you forget to store the outriggers and drive the vehicle, there is a risk that the outriggers will be damaged. There is.

To solve this problem, for example,
As disclosed in the drawings of Publication No. 34915, a solenoid valve is interposed in the oil passage connecting the selector valve and the torque converter clutch, and the solenoid valve is
Some devices use electrical means to turn ON and OFF when the hydraulic pressure supplied to the outrigger reaches a set pressure or higher, but with this method, even when the outrigger piston has not reached the end of its stroke. , if the movement is blocked for some reason,
At that point, the hydraulic pressure reaches the setting and the solenoid valve is activated.
Since it is ON/OFF controlled, for example, when the outrigger base gets caught in an obstacle when raising the outrigger, or if a foreign object gets caught between the cylinder and the base, the solenoid valve will turn ON at that point.
Therefore, it is difficult to say that it is a perfect safety device because the vehicle becomes ready to drive before the outrigger base is fully raised.

SUMMARY OF THE INVENTION In view of the above-mentioned drawbacks, it is an object of the present invention to mechanically compensate for the movement of the outrigger base, thereby making the safety when the outriggers are lowered more stable than in the prior art.

In order to solve this problem, the present invention has disclosed that the torque converter clutch is placed in the neutral position (i.e., the vehicle cannot start) by switching the inching valve via the actuator cylinder by actuation of the brake master cylinder. Focusing on this, the switching of the inching valve is performed by a mechanical connection means using the up-and-down movement of the outrigger as a starting source, without being restricted by the operation of the master cylinder. That is, the outrigger base and the inching valve are linked by a mechanical linking means, and the linking member is activated to follow the up-and-down movement of the outrigger base to switch the inching valve, and the selector valve for controlling the torque converter clutch is set to a position other than neutral. When the outriggers are in the lowered position, the inching valve position is automatically switched to the open position, so there is no pressure oil supplied to the torque converter clutch, making it impossible to start the vehicle. When the outrigger base is in a raised position that does not interfere with the running of the vehicle, the restraining force on the inching valve is released and the valve automatically returns to the closed position, allowing the vehicle to start. Therefore, even if the driver switches the selector valve without checking the outrigger status, the inching valve switching position based on the outrigger status takes priority over the selector valve switching position, and the outrigger base is grounded. It is possible to prevent the vehicle from starting in this state.

Embodiments of the present invention will be specifically described below with reference to the drawings.

FIG. 1 is a side view of the side forklift truck. In the figure, a vehicle body 1 is provided with outriggers 5 and 6, one in each of the front and rear, separated from each other on the side where a fork 3 of a cargo handling device 2 mounted on the vehicle body 1 enters and exits. As shown in FIG. 2, the outrigger is attached to the inner surface of the vehicle body 1 via a bracket 15 around the outer periphery of the outrigger cylinder 7, and is alternately supplied and discharged from oil inlet ports 7a and 7b provided at the upper and lower parts of the outrigger cylinder 7. An outrigger piston rod 8 that can be moved up and down by pressure oil is slidably fitted therein. An outrigger base 9 is tiltably attached to the lower end of the piston rod 8 via a spherical bearing.

At the upper side position of the outrigger cylinder 7,
A guide cylinder 20 is held by the bracket 15 in parallel with the axis of the outrigger cylinder 7, and has a push bar 21 or 22 that slides vertically and downwardly. It has a spring 23 for biasing it. It is preferable that the lower ends of the push bars 21 and 22 be in contact with the upper surface of the outrigger base 9 at least while the outrigger base 9 is in a position that does not interfere with the running of the vehicle.

A horizontal shaft 25 is located above the guide tube 20 of the outrigger 6 provided on the rear side of the vehicle in the left-right direction of the vehicle.
is rotatably attached to the inner surface of the vehicle body 1 via a bracket 26. The horizontal axis 25 includes
An operating lever 33 for operating a swing lever 35, which will be described later, and a connecting member for independently responding to the downward movement of the push bars 21 and 22 to follow the operating lever 33 are installed. As shown in FIG. 4, this connecting member is composed of an arm 24, a fixed lever 27, a disk 28, and a rotating lever 31. 27, a disk 28 having notch teeth 28a protrudingly formed on a side surface opposite to one side surface of an operating lever 33, which will be described later, for transmitting the movement of the fixed lever 27 toward the push bar 22 to the operating lever 33; An arm 24 having a spring 29 attached to its tip for constantly urging the tip of the lever 27 to rotate toward the pusher bar 22 side.
are fixed to the horizontal shaft 25, and have their tips connected to the other ends of the wires 30a of the connectors 30, which have one end connected to the upper end of the pusher bar 21 of the guide tube 20 of the front outrigger 5, and A rotating lever 31 has notched teeth 31a protrudingly formed on a side surface facing the other end surface of an operating lever 33, which will be described later, for transmitting the downward movement of the push bar 21 to the operating lever 33, and one end of a connecting bar 32 at the operating end. The notched teeth 28 of both members 28, 31 are connected to each other, the boss is sandwiched between the disc 28 and the rotating lever 31, and the notch teeth 28 of both members 28, 31 are provided on the side facing both members 28, 31.
An actuating lever 33 having protruding notched teeth 33A that can be engaged with a and 31a, respectively, is loosely fitted onto the horizontal shaft 25.

Next, the hydraulic circuit of the torque converter clutch which controls the starting of the vehicle will be explained with reference to FIG.

A torque converter clutch 40 for switching and operating the vehicle between forward, neutral and reverse travel is in communication with a selector valve 41 via oil passages 42 and 43.
By switching the oil passages 42 and 43, the oil passages 42 and 43 are connected to a drive shaft (not shown) on the forward or reverse side of the vehicle.

The selector valve 41 communicates with a regulator valve 44 via an oil passage 45.

Inching valve 34 communicates with regulator valve 44 and tank T via oil passages 47 and 48, respectively. The inching valve 34 is
By stepping on the brake pedal 50, the brake master cylinder 51 is activated, the actuator cylinder 52 is activated, and the inching cam lever 36 is activated.
The circuit is switched from the closed position to the open position by pushing the tip of the push rod 38 through the switch.

In the above hydraulic circuit device, the swing lever 35 is pivotally attached to the support shaft 37 of the inching cam lever 36, and the upper end of the swing lever 35 is connected to the other end of the connecting bar 32, and the lower end of the swing lever 35 is connected to the inching valve. 34 Pushrods 3
The inching valve 3 is engaged with a pin 39 fixed to the inching valve 8 and
The feature of this embodiment lies in that it is configured to operate 4.

Next, to explain the operation of the above-mentioned device, as shown in FIG. 2 and FIG. When pressure oil is supplied, the outrigger piston rod 8 extends and the outrigger base 9 descends. As soon as the base 9 begins to descend, the push bars 21 and 22 follow and descend by the urging force of the spring 23, and the push bar 21 of the front outrigger 5 is rotated on the horizontal shaft 25 via the wire 30a in the connector 30. In order to pull up the operating end of the lever 31, the lever 31 is rotated in a direction in which the notched tooth 31a of the boss portion engages with the notched tooth 33a of the operating lever 33, and the push bar 22 of the rear outrigger 6 is moved toward the fixed lever 2.
7, the horizontal shaft 25 rotates and the disk 28 rotates at the same time to release the restraint of the lever 27 from the push bar 22 side and allow the spring 29 to lift and rotate the arm 24. , the notch tooth 28a rotates in the direction in which it meshes with the notch tooth 33A of the operating lever 33. Therefore, the actuation lever 33 is forcibly rotated by the rotation of the boss portion of the rotation lever 31 and the disk 28 in the engaging direction, and the upper end of the swing lever 35 is pulled through the connection bar 32. , the lever 35
The outrigger base is rotated about the support shaft 37, and its lower end pushes the push rod 38 of the inching valve 34 against the biasing force of the spring built into the valve 34. The inching valve 34 is switched from the closed position to the open position by the time when the outrigger base 9 separates from the lower end of the push bars 21 and 22 (when the ground clearance of the outrigger base 9 enters a height range that impedes the running direction of the vehicle). complete. In addition, in the above explanation, the forced rotation of the operating lever 33 refers to the forced rotation of the operating lever 33.
1 and the disk 28 at the same time, but if one outrigger base 9 interferes with an obstacle and cannot be lowered, or if one of the outrigger bases 9 naturally lowers due to oil leakage from the cylinder, etc. When only the base 9 is lowered and the other base 9 is not lowered, the disk 28 or rotary lever 31 on the lowered side rotates.
Note that it is forced to rotate.

Therefore, from this point on, the pressure oil that has passed through the regulator valve 44 from the pump P does not flow through the oil passage 45, but flows through the oil passages 47 and 48, and is returned to the tank T. Even if an attempt is made to start the vehicle, the torque converter clutch 40 has no connection with the drive shaft (not shown) and the vehicle is stopped.

Next, when the outrigger cylinder 7 is actuated to lift the outrigger base 9, the outrigger base 9 is moved from the guide tube 2
In order to lift the push bars 21 and 22 against the biasing force of the spring 23 inside the push bar 21, the tip of one push bar 21 is connected to the wire 30a of the connector 30.
The actuating end of the rotary lever 31 is pushed down through the lever 31, and the lever 31 rotates around the horizontal axis 25, moving the notched tooth 31a of the lever 31 in a direction out of engagement with the notched tooth 33a of the operating lever 33. Let me,
The rotational restraint of the operating lever 33 is released. In addition, the tip of the other push bar 22 pushes up the fixed lever 27, thereby causing the horizontal shaft 25
is rotated. At this time, the disk 28 is also rotated at the same time, but as in the case of the rotation lever 31, the rotation is in a direction in which the notch tooth 28a of the disk 28 is disengaged from the notch tooth 33a of the operating lever 33. , the rotational restraint of the operating lever 33 is released.

As a result, the actuating lever 33 is completely unrestrained, and the swing lever 35, which was controlling the inching valve 34, is also unrestrained, so the inching valve 34 is moved by the biasing force of the built-in spring. At the same time, the lower end of the swing lever 35 is pressed to rotate the lever 35, and the operating lever 33 is rotated in the same direction as the rotation direction of the rotation lever 31 via the connecting bar 32. .

Therefore, by operating the selector valve 41 to supply pressurized oil from the pump P through the regulator valve 44, the vehicle can be driven.

If one of the outrigger bases 9, for example the front base 9, cannot rise due to getting caught on an obstacle etc. and only the rear base 9 rises, the movement related to the operation of both bases will be Since the transmission is transmitted to the actuating lever 33 via independent connecting members, the notched tooth 28a of the disc 28 is moved to the actuating lever 33 by pushing the push bar 22 up toward the fixed lever 27 as the rear base 9 rises. Even if the front base 9 rotates in the direction out of engagement with the notch teeth 33a, the front base 9 does not move upward, and the push bar 21
Since this does not operate, the rotating lever 31 also maintains its current state, and the notched teeth 31a and 33a of the rotating lever 31 and the operating lever 33 are also in a screwed state, so the operating lever 33 is restrained by the rotating lever 31. condition, and the swing lever 35 is also inching valve 34.
remains in the open position, making it impossible for the vehicle to move.

As described above, according to this embodiment, the inching valve is switched on and off independently of the operation of the brake pedal by the vertical movement of the push bar that moves up and down following the up and down movement of the outrigger base, and the torque converter clutch is Since it is possible to control the supply and discharge of pressure oil to and from the outriggers, the start of the vehicle is reliably prevented when the outriggers are lowered, thereby ensuring safety. Further, there is a practical advantage that it can be implemented extremely easily and inexpensively without changing the conventional hydraulic circuit device.

Further, the rotation lever 31 and the actuation lever 33 are loosely fitted to the horizontal shaft 25, and the movements related to the movements of the front and rear outriggers act on the actuation lever through independent transmission mechanisms. Therefore, even if one of the outrigger bases of the outriggers 5 and 6 cannot be lowered due to an obstacle or the like, and the base does not separate from the pusher bar, the outrigger base will continue to rotate as long as the other outrigger base can be lowered. Since the lever 31 can rotate the actuating lever 33 on the disk 28, the inching valve is switched to the open position, thereby reliably preventing the vehicle from starting.

Note that the same effect as described above can be obtained by using the piston rod of the outrigger instead of the push bar in the above embodiment, and having its upper end protrude upward and linking it to the actuating lever via a connecting member.

[Brief explanation of the drawing]

The drawings show one embodiment of the present invention, Fig. 1 is a side view of a side forklift truck equipped with the present invention, Fig. 2 is an explanatory view showing the main parts, and Fig. 3 is A-A in Fig. 2. 4 is a perspective view showing the main parts, and FIG. 5 is a hydraulic circuit diagram. 1... Vehicle body, 5, 6... Outrigger, 8... Outrigger piston rod, 9... Outrigger base, 20
...Guide tube, 21, 22...Push bar, 23...Spring, 24...Arm, 25...Horizontal shaft, 27...
Fixed lever, 28... Disk, 29... Spring, 30... Connector, 31... Rotating lever, 32... Connecting bar, 33... Operating lever, 34... Inching valve, 35... Swing lever, 40... Clutch,
41...Selector valve, T...Tank.

Claims (1)

[Claims] 1. The torque converter clutch is disengaged by the operation of an inching valve that is linked to an actuator cylinder that is driven by a brake master cylinder, and at least
In an industrial vehicle in which outriggers are installed, one end of a swing lever that enables switching of the inching valve independently of the switching operation by the actuator cylinder, and a swing lever that moves up and down following the up and down movement of the outrigger base. With Pushyuber,
A safety device for lowering an outrigger in an industrial vehicle, characterized in that the inching valve is opened when the pusher bar is lowered, and the inching valve is closed when the pusher bar is raised.