JPS64320B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a free-falling mechanism in a winch device using a radial piston type hydraulic motor whose outer casing rotates.

When lowering a suspended load using a winch device, normally power is lowered, but the lowering speed is increased,
In order to shorten the working time, the rope drum and the drive system are often separated, and the rope drum is left in a freely rotating state and allowed to freely descend by the force of gravity acting on the suspended load or hook.

For this purpose, there was a structure in which a clutch was installed between the rope drum and the drum drive shaft, and the hanging load etc. was allowed to fall freely by the connecting and disconnecting action of this clutch, but in a more advanced structure, the outer casing rotates. A type of radial piston type hydraulic motor with a mechanism that allows the piston of the hydraulic motor to freely descend without using a special clutch by releasing the connection with the external casing that connects the piston of the hydraulic motor to the rope drum is also used. It became.

However, even in such a free-fall mechanism,
Since it can be freely lowered regardless of the size of the suspended load, when lowering a relatively heavy suspended load, it is necessary to use a winch device, an attached brake mechanism, and a crane device equipped with this. There was a risk of damage.

The present invention provides a novel free-fall mechanism that completely eliminates the above-mentioned risks, and is constructed as shown in the following embodiments.

In FIG. 1, 1 is a radial piston type hydraulic motor (hereinafter simply referred to as a hydraulic motor) whose outer casing rotates, and 2 is a rope drum rotationally driven by the hydraulic motor 1. As shown in FIG. 3 is a hydraulic pump that sucks and discharges hydraulic oil from tank 4;
The direction of supply of the hydraulic fluid discharged thereby is switched by the directional switching valve 5 and supplied to the hydraulic motor 1, thereby causing the hydraulic motor 1 to rotate forward or reverse. Note that 6 is a back pressure holding valve to prevent the hydraulic motor 1 from running automatically, and 7 is a relief valve that sets the maximum pressure in the hydraulic circuit.

The structure of the above-mentioned hydraulic motor 1 will now be explained in detail as follows. In FIG. 2, 101 is a fixed shaft, and boats 102 and 103 for supplying and discharging hydraulic oil are provided here. port 102
is a pressure oil inflow port when the rope drum 2 is being wound down, and port 103 is a pressure oil inflow port when the rope drum is being wound up. At the end of the fixed shaft 101, there is a distribution valve 104 formed with two chamfers, through which the hydraulic oil introduced from the ports 102 and 103 is distributed. 105 is a pentagonal cylinder block that rotates around the distribution valve section 104 and houses five pistons, and these five pistons 106 alternately contact the low pressure side and the high pressure side of the distribution valve section 104. The hydraulic oil is repeatedly drained and supplied. Reference numeral 107 denotes an outer casing having a pentagonal inner surface, the inner wall of which is adapted to receive the bush of the piston 106 on the high pressure side. The center of rotation thereof is eccentric from the axis of the fixed shaft 101, and the pentagonal surfaces of the cylinder block 105 rotate in the same phase by a synchronizing pin/ring mechanism (not shown). It's becoming like that. Therefore, the combined force of the forces acting on the high-pressure side piston 106 generates a torque on the outer casing 107, so the outer casing 107 rotates in the direction of the arrow in the figure. Further, as described above, since the cylinder block 105 rotates together with the outer casing 107, the phase of the distribution valve portion 104 also advances in sequence, and rotation can be performed continuously. In addition, if the directional control valve 5 is operated in the opposite direction to the case described above to connect the high pressure side to the port 102 and the low pressure side to the port 103, the hydraulic motor 1 will of course rotate in the direction opposite to the arrow in the figure.

Next, the operation of the hydraulic motor 1 in the free rotation state will be explained based on FIG. 3. 108 is the inside of the casing divided by the outer casing 107, the cylinder block 105, and the piston 106. During rotation drive, only drain pressure is applied here, but when it is in a free rotation state, pilot pressure is introduced here to generate pressure. It will be built. By building up the internal pressure of the casing and connecting the ports 102 and 103 to the tank in this way, the piston 106 is pushed into the cylinder block 105, and since there is no flow of hydraulic oil in and out, the same effect as just disengaging the clutch can be obtained. The outer case 107 can be rotated freely.

As described above, the hydraulic motor 1 rotates under power or freely rotates, and the external casing 107 is provided with a shaft (not shown) on the opposite side of the fixed shaft 101, and the hydraulic motor 1 is rotated by power or freely. Since it is connected to the rope drum 2, it is possible to drive this rope drum 2 by power and also to allow the rope drum 2 to freely descend by the force of gravity acting on the suspended load.

Now, returning to FIG. 1 and continuing the explanation of the present invention,
8 is a tank circuit arranged between the port 103 and the tank 4, and a regulating valve 9 is interposed in the middle. 10
1 is a pilot circuit which guides the hydraulic oil supplied from the auxiliary pump 11 into the casing interior 108, and 12 is a set pressure adjustable relief valve that regulates the pilot pressure. Reference numeral 13 denotes a free-fall selection valve (hereinafter referred to as selection valve) inserted into the pilot circuit 10 at the port 2 position, and when in the position, pilot pressure oil can be supplied to the inside of the casing 108, and the position can be selected. When this happens, leaked oil inside the casing 108 can be drained via the branch circuit 14.

Further, this selection valve 13 can be detented in one position or another.

The details of the regulating valve 9 are shown in FIG. 4, and a poppet 903 is inserted into a valve seat 902 bored in a valve body 901 and urged in the seating direction by a spring 904. 905 is a screw for adjusting the spring force, and 906 is a lock nut. On the other hand, a pilot piston 909 is interposed in opposition to this poppet 903, and this pilot piston 909 receives pilot pressure from a pilot oil passage 910 branched from the pilot circuit 10, and acts in a direction to push the poppet 903 open. It's becoming like that. Reference numeral 907 is a port that connects the valve chamber 908 surrounding the poppet 903 and the tank circuit 8 on the port 103 side of the hydraulic motor 1. Also 91
1 is a valve chamber 9 surrounding a pilot piston 909;
12 and the tank circuit 8 on the tank 4 side. The valve chamber 908 and the valve chamber 912 are the valve seat 90
The two parts are connected to each other through an oil passage 913 bored in the two parts. With this structure, when the pilot piston 909 pushes open the poppet 903, the regulating valve 9 opens and releases the pressure oil on the port 103 side to the tank 4, but otherwise the circuit is closed. The conditions under which the regulating valve 9 opens and closes are explained below. Poppet 903 is spring 9
04 auxiliary force and port 103 side (valve chamber 908 side)
The pressure of the pilot circuit 10 is
Since it opposes the pilot piston 909 that receives Pp, the poppet 903 that controls the opening and closing of the regulating valve 9 has a force of [(Pm・Am)+F],
The forces (Pp・Ap) are acting in opposition.

However, Am is the pressure receiving area of poppet 903, Ap
is the pressure receiving area of the pilot piston 909, and F is the biasing force of the spring 904.

Then, if (Pm・Am+F)≧Pp・Ap, the regulating valve 9 is closed, and (Pm・Am)+F<Pp・
If it is Ap, the regulating valve 9 will be open.
Since Am and Ap are constant, the pressure Pm corresponding to the hanging load of the hydraulic winch when the regulating valve 9 is open (this is the pressure of the pressure oil inflow port 103 of the hydraulic motor 1 when hoisting the rope drum). ) can be arbitrarily set by adjusting the biasing force F of the spring 904 or the pressure Pp of the pilot oil passage 10.

In this embodiment, the same pilot circuit 10 is used to introduce the pilot pressure into the casing interior 108 and the regulating valve 9, but these may be introduced using separate pilot circuits.

Now, returning to FIG. 1 again, we will describe the operation and effect when freely lowering the winch device of the present invention. In this case, the directional control valve 5 is set to the neutral position, and the selection valve 13 is set to the position by manual operation. By setting the directional control valve 5 to the neutral position, the port 102 side of the hydraulic motor 1 is released to the tank 4 and becomes 0 pressure, but the port 103 side is connected to the back pressure holding valve 6 and the regulating valve 9 to the suspended load W. The resulting confining pressure (i.e. load
Pm) is occurring. However, on the other hand, since the selection valve 13 is in the position, if the pilot pressure oil is applied to the inside of the casing 108 and the regulating valve 9 is pushed open at the same time, the port 103 side is also released to the tank 4 and becomes 0 pressure. At this time, the pressure acting on the piston 106 is 0, but the pressure inside the casing 108 has increased due to the aforementioned pilot pressure, so the piston 106 is pushed into the cylinder block 105 and the piston 106 is pushed into the cylinder block 105.
The outer casing is uncoupled (the state shown in FIG. 3), and the outer casing 108 and the rope drum 2 connected thereto are in a freely rotating state,
The hook and suspended load will fall freely. By returning the selection valve 13 to its position, the pilot pressure is released to the tank 4, and the regulating valve 9 is closed again, so that the hydraulic motor is prevented from freely rotating. Furthermore, if the directional control valve 5 is operated from this state, the hydraulic motor 1 will naturally rotate under power.

The opening condition of the regulating valve 9 can be varied by changing the spring biasing force F and the pilot pressure Pp, as described above. Therefore, if you want to keep the pilot pressure Pp constant, increasing the spring force F will reduce the load pressure.
Pm, that is, the hanging load W can be freely lowered only when it is small, and if the spring biasing force F is reduced, even when the hanging load W is large, it can be lowered freely. Furthermore, similar adjustment can be made by keeping the spring biasing force F constant and changing the pilot pressure Pp, but in this case, if the pilot pressure Pp is small, the suspended load W is small, and if the pilot pressure Pp is high, the suspended load is Even if W is large, it can be made to fall freely.

Since the device of the present invention is configured as described above,
Spring force F of regulating valve 9 and pilot pressure Pp
By appropriately setting , it is possible to set restrictions such as allowing only the hook or only light loads to fall freely, and preventing free fall in the case of heavy loads. It is possible to completely eliminate the risk of damage to the winch device, etc., which occurs when a suspended load is freely lowered.

[Brief explanation of the drawing]

Fig. 1 is a hydraulic circuit diagram related to the device of the present invention, Fig. 2 is a structural explanatory diagram of the hydraulic motor 1 used in the device of the present invention, Fig. 3 is a state diagram of the hydraulic motor 1 in a free rotation state, and Fig. 4 is a diagram showing the state of the hydraulic motor 1 in a free rotation state. 3 is a detailed structural diagram of the regulating valve 9. FIG.

Claims (1)

[Claims] 1. A radial piston type hydraulic motor that can press the piston into the cylinder block by making the internal pressure of the casing higher than the pressure acting on the piston, and release the connection between the piston and the outer casing to freely rotate the outer casing, and the hydraulic motor. A winch device comprising a rope drum rotationally driven by a motor,
The hydraulic motor is configured so that hydraulic pressure can be applied to and released from the casing of the hydraulic motor via a pilot circuit, and the pressure oil inflow port of the hydraulic motor when hoisting a rope drum is connected to a tank by a tank circuit equipped with a regulating valve. However, this regulating valve is biased in the closing direction by a spring and the hydraulic pressure on the hydraulic motor side of the tank circuit in which the regulating valve is installed, and is applied to the inside of the casing of the hydraulic motor via the pilot circuit. 1. A free-falling mechanism in a hydraulic winch, characterized in that the mechanism is configured to be biased in a releasing direction by hydraulic pressure.