JPH0241509B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Application of the Invention] The present invention relates to a winch device installed on land, a ship, a mobile crane, etc., and particularly relates to a winch device having a free fall function. [Background of the Invention] Figures 2a and 2b are explanatory diagrams showing an example of this type of conventional winch device. Figure 2a is a side sectional view showing the winch drum portion, and Figure 2b is a side sectional view showing the hydraulic circuit portion. FIG. Reference numeral 1 shown in FIG. 2a is a planetary reducer, the ring gear 2 of which is always fixed, and the rotational output of the hydraulic motor 8 is transmitted via the sun gear 3 and is decelerated and output to the carrier shaft 4. An internally expandable band clutch 5 is integrally provided on the carrier shaft 4, and the band clutch 5 is arranged so as to be able to come into contact with the inner periphery of a brake drum 7 that is provided integrally with the winch drum 6. Note that 9 and 10 are rolling bearings that rotatably support the carrier shaft 4 and the winch drum 6, 12 is a clutch release cylinder for releasing the band clutch 5, 13 is a spring housed in the clutch release cylinder 12, and 14 is a fluid rotary joint connected to the carrier shaft 4 and guiding pressure oil to the clutch release cylinder 12. Further, numeral 11 is a band brake for braking the brake drum 7, as shown in FIG. 2b. 2B, 28 is a brake release cylinder for releasing the braking by the band brake 11, 29 is a spring housed in the brake release cylinder 28, 30 is a brake pedal capable of holding the band brake 11 in a braking state, and 31 is a brake release cylinder that releases the braking by the band brake 11. brake pedal 3
This is a spring that biases the brake pedal 30 so that the braking caused by 0 is released. 24 is a switching valve connected to the fluid rotary joint 14 described above, 23 is a clutch lever that drives this switching valve 24, and 27 is a hydraulic pilot switching valve connected to the brake release cylinder 28 described above. are in contact with each other. Also, 2
Reference numeral 6 designates a directional switching valve for controlling the drive of the aforementioned hydraulic motor 8, and 25 designates a hydraulic pilot valve for switching the directional switching valve 26. The pilot pressure generated by the hydraulic pilot valve 25 is also sent to the aforementioned switching valve 27, and the switching valve 27 is switched by the pilot pressure. 32 is an operating pressure pump that is connected to the hydraulic pilot valve 25 and the switching valves 24, 27 and supplies pressure oil to these valves 25, 24, 27; 33 is an operating pressure relief valve that sets the discharge pressure of the operating pressure pump 32; It is. The operation of the winch device configured in this way is as follows. That is, for example, when hoisting or lowering is performed by driving the hydraulic motor 8, the clutch lever 23 is operated and the switching valve 24 is switched to the position ◯ in FIG. 2b. As a result, the clutch release cylinder 12
The pressure is released to the tank, and the band clutch 5 is pressed against the brake drum 7 by the force of the spring 13, so that the clutch is connected. When the hydraulic pilot valve 25 is in the neutral position as shown in FIG. 2b, the switching valve 27
is in the position of ◯C, so the pressure in the brake release cylinder 28 is released to the tank, and the band brake 11 is pressed against the brake drum 7 by the force of the spring 29, so that the brake drum 7 is in a braking state. Note that the brake drum 7 can also be put into the braking state by depressing the pedal 30, but when the hydraulic pilot valve 25 is in the neutral position as described above, it is not necessary to perform the braking operation using this pedal 30. Of course not. Next, from the neutral position of the hydraulic pilot valve 25, when the hydraulic pilot valve 25 is tilted to the hoisting side or the hoisting side, the direction switching valve 26 is switched and the hydraulic motor 8 starts rotating. do. At the same time, hydraulic pilot valve 2
The pilot pressure generated in step 5 switches the switching valve 27 to the ○ position shown in FIG. Braking is released. As a result, the rotational force of the hydraulic motor 8 is reduced in speed and transmitted to the carrier shaft 4 via the sun gear 3 and ring gear 2 of the planetary reducer 1 shown in FIG. The brake drum 7, that is, the winch drum 6 integrally provided with the brake drum 7, rotates via the clutch 5, thereby performing desired hoisting and lowering operations. Further, when performing a freefall, first the brake pedal 30 is depressed against the force of the spring 31, and the band brake 11 is pressed against the brake drum 7, thereby bringing the brake drum 7 into a braking state. Next, the clutch lever 23 is operated to switch the switching valve 24 to the position shown in FIG. 2b. As a result, pressure oil from the operating pressure pump 32 is guided to the clutch release cylinder 12 shown in FIG. 2a and the brake release cylinder 28 shown in FIG. 2b, and the springs 13, 29
contracts, the clutch connection by the band clutch 5 is released, and the brake release cylinder 28
The brake drum 7 is no longer braked by the brake pedal 30, and the brake drum 7 is braked only by the brake pedal 30. Here, loosen the brake pedal 3.
Raise it to 0 to start a free fall. In this case, when braking the brake drum 7, the brake pedal 30 may be depressed again. However, the conventional clutch device configured as described above has the following problems. (1) In addition to the brake pedal 30, a clutch release cylinder 12, a switching valve 24 for operating this clutch release cylinder 12, a clutch lever 23 for switching this switching valve 24, etc. are required, and the brake pedal 30 and brake release cylinder 28 are also required. Since a complicated link mechanism is required to operate the band brake 11 in conjunction with both, the overall number of parts is large, the structure becomes complicated, and the cost of the structure tends to increase. (2) When moving from hoisting and lowering operations to free fall operation, a complicated operation is required after depressing the brake pedal 30, switching the clutch lever 23, and then gradually raising the brake pedal 30. The free fall operation is poor. (3) When the brake pedal 30 is not depressed, the brake drum 7 is
There are cases where the brake drum 7 is being braked and cases where the brake release cylinder 28 is activated and the brake drum 7 is released from braking.In other words, just by looking at the state of the brake pedal 30, the brake drum 7 is in the braking state. Therefore, malfunctions are likely to occur in connection with the operation of the switching valve 24. Note that this malfunction may cause a serious accident in which the suspended load falls. (4) If the engine stalls with a load suspended, pressure oil will not be supplied to both the clutch release cylinder 12 and the brake release cylinder 28, so the force of the springs 13 and 29 will release the band clutch 5,
Both band brakes 11 are activated, the winch drum 6 stops, and therefore the load cannot be unloaded. In addition to the above, there are other drawbacks specific to the clutch portion shown in FIG. 2a, as listed below. The internally expandable band clutch 5 must be constructed to withstand a large transmission force in a limited space, is problematic in terms of reliability, has a large number of parts, and is expensive. An expensive fluid rotary joint 14 is required to supply pressure oil to the declutching cylinder 12. Since the band clutch 5 and the like are arranged inside the brake drum 7, maintenance and inspection are troublesome. In addition, in order to facilitate maintenance and inspection, it is sufficient to leave sufficient space on the end face of the band clutch 5, but for example, in a limited space such as a mobile crane, a rope with a larger winding capacity can be used. This is difficult to accommodate for applications that require a winch (with a wide drum width). In view of the above-described drawbacks of the winch drum portion shown in FIG. 2a, other winch drum portions shown in FIGS. 3 and 4 have been proposed. In the winch drum part shown in FIG. 3, a clutch 15 is provided between the output shaft of the hydraulic motor 8 and the planetary reducer 1, the ring gear 2 is always fixed so that it can receive the torque reaction force, and the carrier shaft 16 is connected to the ring gear 2. It is constructed integrally with the winch drum 17. Although the winch drum section constructed as shown in FIG. 3 eliminates the disadvantages mentioned above since it does not require an internally expandable band clutch, it has other disadvantages listed below. ○…

Claims (1)

[Claims] 1. A winch device comprising a winch drum, a motor that rotates the winch drum and can rotate in either direction, and a planetary reducer that reduces the rotational force of the motor and transmits it to the winch drum. A first braking device including a hydraulically driven brake release cylinder that brakes rotation of the input shaft of the planetary reducer is provided, and one of the ring gear and the carrier shaft of the planetary reducer is integrated with the winch drum. A brake drum is formed integrally with one of the other winch drums and is separate from the winch drum, and a second brake device is provided for braking the rotation of the brake drum by human operation via a link mechanism. A winch device characterized by: