JPS582193A - Preventive device for overwinding of wire in hydraulic crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION This invention is intended to automatically and reliably prevent wires from exceeding 4 It in advance in mobile cranes and hydraulic cranes installed in industrial vehicles at Cape Heidschifran! Regarding all equipment.

As is well known, when lifting the front body of this type of hydraulic crane, if the wire is raised above the allowable limit,
The hook crashed into the boo's 50-year-old bulge, causing his back to fall.
To prevent damage to the wire, a weight for activating the reset switch is installed at a position slightly lower than the fixed end of the wire, and when the hook comes into contact with this weight, #! :
There is a device to set the reset switch OyI and sound the alarm.

However, conventional over-the-counter alarm devices detect when the wire is wound up to the permissible limit and simply issue an alarm (
It only has the function of sounding the horn (horn), and if the sound of the horn is accidentally missed or the winch lever operation is delayed, it is still possible to overwind the wire, so it is safe. Since the electrical circuit of the 9-mitsuto switch has a constant contact configuration, if the electricity @S is disconnected or the power is cut off due to some reason, the alarm may not sound at all. .

This invention was developed to solve the above-mentioned problem (1). A bypass circuit is attached to the drive circuit of the hydraulic motor that rotates the winding drum, and solenoid pulp and check pulp are connected to this bypass circuit (1I). A switch is installed at the tip of the pool for detection of oversight, which is always in the state of OM (S) and becomes the state of W when the footer rises to a predetermined position. -σ Reverse operating loop pair of 9V- is interposed to switch the solenoid pulp SII!t, and the drive circuit of the hydraulic motor to bypass @S. The structure and operating procedure of the oversight prevention device according to the present invention will be explained in detail with reference to the opening of the embodiment.
) is the winding drum of the winch that springs up the wheel-ff), (2) is the hydraulic motor that rotates the winding drum (1), and the drive 1118111) of the hydraulic motor (1118111) is the third
A bypass amIQ is provided as shown in the figure.
In this bypass circuit Q, a solenoid pulp (3) and a check pulp (4) are arranged in order from the winding side toward the spring side. Also, Fig. 2 shows the electric circuit 0 for operating the solenoid pulp (3), and this electric Wi181! b3) Inside the boom (S) of the hydraulic crane, there is a 9-dragon switch for detection of oversight, which is connected to the end of the boom (S) (on the normal side) and becomes the value state when the hook (shape) rises to a predetermined position. 7) and a pair of relays (8) (U) which operate in reverse according to the signal of this switch (1). main switch shaft,
It is equipped with a fuselage red biloft lamp (2), a blue pilot lamp (b), and an oversight warning horn - an emergency push button switch.

Since the oversight prevention device of the present invention has the above-mentioned structure, in the normal state,
In other words, for poems in which the wire (B) is normally resounding within the range of allowable Sm, the reset switch (7) is set to OFF.
Coil e141 because it is lni! A current flows through l,
The contacts of one relay (8) linked to this are on the side, and the contacts of the other relay (8) are in the shape of ψ (1IK-).
Since pressure oil is flowing through ), the hydraulic motor ( ) is rotating under pressure. However, wire-)
As the spring rise progresses, the hook (6) rises to the predetermined eye position and hits the weight for activating the limiter switch, the suspension rope Q7φ of the S weight loosens and the 9-point switch is activated.
is disconnected, relay (11) is Cff, and the other 9V-(
1) becomes ON state lI, actuating the solenoid pulp (3) and switching the pressure oil from the drive circuit Oυ of the hydraulic motor (!) to the bypass circuit 0, so at this point the hydraulic motor drive circuit and the When the pressure becomes zero, the winding of the winding drum (1) is immediately stopped, and at the same time, the red piping lamp lights up and the overwatch warning horn sounds.

In this case, the limit switch (7) that stops the operation of the hydraulic motor (2) is different from the conventional oversight prevention device.
Since the contact structure is always open, if there is a break in the electrical circuit in this part or the power is cut off, the hydraulic circuit switch will switch so that the hydraulic motor Q) will automatically stop. Ru. In addition, even when the above-mentioned oversight prevention device is activated, the inspection drum (reverse rotation loading and unloading of υ) is possible, and if the emergency push-button switch ■ is actuated, the oversight prevention device can be activated. Even when activated, the winch can be driven in an emergency manner, and if you release your hand from the emergency push-button switch, it will automatically return to its original state.

As described above, the oversight prevention device of the present invention senses when the wire is raised up to the allowable IF limit point and immediately stops the rotation of the inspection drum, thereby preventing the wire from being overwound. Not only can it be automatically activated, but even if there is a break in the electrical circuit or the power is cut off for some reason, the device always works so that the hydraulic motor stops, so it is possible to automatically stop the hydraulic motor. Unlike conventional devices that only have the following functions, this device is extremely safe, and the device is extremely easy to handle and operate, making it extremely effective in use.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an example of a vehicle equipped with the oversight prevention device of the present invention, Fig. 2 is a wiring diagram showing the electric circuit of the device, and Fig. 3 is a piping diagram showing the main parts of the hydraulic circuit of the device. Yes (1)... End-of-life drum, (ri... Hydraulic motor, (3)
... Solenoid pulp, 0) ... Check pulp, (5
)...Boom, (6)...Hook, (7)...Limit switch, (8)(9)...Relay 1::

Claims (1)

[Claims] A bypass circuit is attached to the drive circuit of the hydraulic motor that rotates the inspection dot in the U direction, and a solenoid pulp and a check valve are installed in this bypass circuit. A reset switch for detecting oversight is installed, which is connected at A wire oversight prevention device in a hydraulic crane, characterized in that the solenoid pulp of the hydraulic crane is opened and closed to switch the drive circuit of one hydraulic motor to a bypass circuit.