JPS5943400B2 - Brake device for winch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a brake device for a winch such as a crane.

The winches of cranes, etc. are equipped with negative brakes that operate when the winches are not operating.

In order to improve work efficiency in such a winch brake device, when the winch is not operating, the brake force can be controlled by the brake operating device to prevent free fall (hook). or free descent due to the weight of the suspended load).

By the way, in the conventional winch brake device,
During a freefall operation, the brake force is reduced as the amount of operation of the brake operating device increases, for example, the more the brake pedal is depressed. The structure is such that the braking force becomes larger as the brake force increases.

As a result, when a suspended load, etc. accelerates too much during a freefall operation and an emergency stop is required, the driver confuses it with a normal brake operation and accidentally depresses the brake pedal further, causing the speed of the suspended load to increase even further. There are cases where people make the mistake of putting it away.

Therefore, a brake device for a winch is considered in which the braking force increases as the amount of operation of a brake operating device, such as a brake pedal or a brake lever, increases during a free fall operation.

However, with such a winch brake device, if you accidentally take your foot off the brake pedal during a free fall operation, the braking force will be at its minimum, so there is a danger that the suspended load will fall. be.

This invention was made in order to solve the above-mentioned problems, and is a winch that eliminates the risk of suspended loads falling even if the driver accidentally releases his or her foot or hand from the brake operating device during free fall operation. The purpose is to provide a brake device for

In order to achieve this object, the present invention provides a brake device used for a winch that includes a clutch between a winch drum and an output shaft of a hydraulic motor that drives the winch drum, and a clutch switch that releases the clutch. , a brake operating device, a brake operating switch that is turned on when the operating amount of the brake operating device exceeds a predetermined value, and a directional control valve that operates the hydraulic motor is in an operating position, and the clutch is released and a brake release cylinder that extends when the brake operation switch is turned on; a first spring receiver fixed to the tip of the piston rod of the brake release cylinder; a second spring receiver; and the first and second spring receivers. A rod is movably supported by a spring receiver, and the first spring receiver of the rod has a first stopper fixed to a side end, and a second stopper fixed to a substantially central portion of the rod. a brake spring provided between the second spring receiver and the third stopper; and a spring force of the brake spring between the first spring receiver and the second stopper. a free fall spring provided in a compressed state; a first link pin-coupled to the brake operating device;
A long hole provided in the first link and a second link which is rotatably supported, to which the end of the brake band is attached, and which is pin-coupled between the second and third stoppers of the rod. A second link and a pin provided on the second link and engaged with the elongated hole are provided.

FIG. 1 is a diagram showing a winch brake device according to the present invention.

In the figure, 1 is a hydraulic pump, 2 is a hydraulic motor, 3 is a manual three-position directional control valve inserted between the hydraulic pump 1 and the hydraulic motor 2, 4 is a tank, 5 is an operating lever for the directional control valve 3, 9 is a winch drum rotated by the hydraulic motor 2; 10 is a brake band hung on the drum 9;
One end of the brake band 10 is fixed.

11 is a power source, 12 is a lever switch, 21 is a hydraulic pump, and 22 is a relief valve, and the relief valve 22 is for supplying constant pressure oil to a clutch cylinder and a brake release cylinder (described later).

23 is a clutch attached to the drum 9; 24 is a clutch cylinder for operating the clutch 23; and 25 is a two-position solenoid directional control valve provided between the clutch cylinder 24 and the hydraulic pump 21.

Also, 26 is the brake release cylinder, 27 is the cylinder 2
6 is a piston rod, 28 is a spring receiver fixed to the tip of the piston rod 27, 29 is a rod whose both ends are movably supported by spring receivers 28 and 30, respectively, 31 is a stopper fixed to the rod 29, and 32 is a stopper. The spring receiver provided in contact with 31, 33 is the spring receiver 30°32
Brake spring installed between 0, 34, 35 Harrods 2
9 is a stopper fixed to it, 36 is a spring receiver provided in contact with the collar 35, 37 is a free fall spring provided between the spring receivers 28 and 360, and the free fall spring 37 is a spring force of the brake spring 33. Although it is compressed to the above degree and its expansion is restricted by the stoppers 34 and 35, it is free to contract.

38 is a two-position solenoid directional control valve provided between the cylinder 26 and the hydraulic pump 21, 39 is a rotatably supported link, and the end of the brake band 10 is attached to one end of the link 39. The center portion of the link 39 is rotatably attached to the rod 29.

40 is a rotatably supported brake pedal; 41 is a pedal return spring having one end fixed and the other end fixed to the end of the brake pedal 40; 42 a rod rotatably attached to the brake pedal 40; 42a is a long hole provided at the end of the rod 42, and a pin 39a provided at the end of the link 39 is engaged with the long hole 42a.

Further, reference numeral 43 indicates a fixed column; 44 indicates a lever attached to the column 43 so as to rotate when a rotational force is applied, but to remain stationary when no rotational force is applied; 45;
46 are adjustment bolts screwed into the arms 44a and 44b of the lever 44, and 4γ and 48 are adjustment bolts 4, respectively.
5. A lock nut screwed into 46, 49 a pedal plate fixed to the brake pedal 40, and 50 a support column 43.
A pedal switch attached to the pedal switch 50.
The contact piece is pressed against the lever 44 by a spring or the like (not shown).

51 is a clutch switch, a connection terminal 51a of the clutch switch 51 is connected to the power source 11, a contact 51b is connected to the connection terminal 12a of the lever switch 12, and a contact 51c is connected to the contact 50b of the pedal switch 50 and the directional control valve 25. It is connected to the solenoid, and further connected to the connection terminal 50a of the pedal switch 50 and the lever switch 1.
Both the 20 contacts 12b and 12c are connected to the solenoid of the directional control valve 38.

Next, the operation of this brake device will be explained.

First, the state shown in Fig. 1, that is, the hydraulic motor 2 (drum 9)
is not rotating, the lever switch 12 is off and the directional control valve 38 is in the position shown in FIG. It is pushed in the direction of the arrow by the spring 33.

Therefore, the link 39 is pushed counterclockwise, and the brake is activated.

When operating the operating lever 5 from this state to switch the directional switching valve 3 and rotate the hydraulic motor 2, the lever switch 12 is turned on and the directional switching valve 38 is switched, so that the pressure oil from the hydraulic pump 21 is turned on. It is supplied into the chamber of the cylinder 26.

Therefore, the piston rod 27 moves in the direction opposite to the arrow, and the rod 29 moves in the opposite direction to the arrow, against the brake spring 33.

As a result, the link 39 is rotated clockwise as shown in FIG. 2, so that the brake is released.

Note that, in this case, the free fall spring 37 is compressed more than the spring force of the brake spring 33, so the free fall spring 37 does not contract.

When the rotation of the hydraulic motor 2 is stopped by operating the operating lever 5 from this brake released state, the lever switch 12 is turned off and the directional control valve 38 is switched to the state shown in FIG. is connected to tank 4.

As a result, the rod 29 is moved in the direction of the arrow by the brake spring 33, and the link 39 is rotated counterclockwise, so that the brake is activated.

When the brake pedal 40 is depressed in this state, the third
As shown in the figure, the brake pedal 40 rotates clockwise against the pedal return spring 41.

Therefore, since the pedal plate 49 pushes the adjustment bolt 45, the lever 44 rotates clockwise as shown in FIG. 4, and the pedal switch 50 is turned on.

Further, when the brake pedal 40 rotates clockwise, the rod 42 moves in the direction of the arrow, and the pin 39a
engages with the left end of the elongated hole 42a.

When the clutch switch 51 is switched to the contact 51c side in this state, the directional switching valves 25 and 380 solenoids are energized, the directional switching valves 25 and 38 are switched from the state shown in FIG. 1, and the clutch 23 comes into contact with the drum 9. Drum 9 from condition
At the same time, pressure oil from the hydraulic pump 21 is supplied into the cylinder 260 chamber, and the piston rod 27 moves in the opposite direction to the arrow.

In this case, since the pin 39a is engaged with the left end of the elongated hole 42a, the rod 29 does not move, so the free fall spring 3γ is compressed as shown in FIG. , the driver can confirm that free fall maneuvers are possible.

In this free fall state, if the force applied to the brake pedal 40 is reduced, the rod 29 is pushed in the opposite direction to the arrow by the free fall spring 37, so the brake pedal 40 rotates counterclockwise. The rod 42 and the rod 29 move in the direction opposite to the arrow direction, and the link 39
Since the brake band 10 rotates clockwise, the brake band 10 separates from the drum 9, the braking force decreases, and the suspended load etc. freely descends.

In other words, a free fall is performed.

In this case, even if the pedal plate 49 separates from the adjustment bolt 45 as shown in FIG. 5, the lever 44 does not rotate, so the pedal switch 50 does not change.

Conversely, when the brake pedal 40 is depressed, the rod 29
moves in the direction of the arrow against the free fall spring 3γ, the link 39 rotates counterclockwise, and the brake band 10 comes into contact with the drum 9, thereby increasing the braking force.

In this way, in this braking device, the brake is applied when the brake pedal 40 is depressed in the same way as a normal brake.

Then, when you take your foot off the brake pedal 40,
Since the brake pedal 40 is rotated counterclockwise by the pedal return spring 41, the lever 44 is rotated counterclockwise because the pedal plate 49 pushes the adjustment bolt 46.
Pedal switch 50 is turned off.

Therefore, the energization to the solenoid of the directional control valve 38 is cut off, so the directional control valve 38 is switched to the state shown in FIG. 1, and the interior of the cylinder 26 is connected to the tank 4.

As a result, the free fall spring 37 causes the rod 29 to
moves in the direction of the arrow, and the brake is activated.

If it is desired to perform a free fall operation again from this state, the brake pedal 40 may be depressed to the state shown in FIG. 4.

It should be noted that in order to enable free fall operation, it was stated above that the brake pedal 40 is first depressed to the state shown in FIG. 4, and then the clutch switch 51 is switched. Afterwards, the brake pedal 40 may be depressed.

That is, when the clutch switch 51 is switched to the contact point 51c side, the clutch 23 becomes separated from the drum 9, but since the brake is activated by the brake spring 33, the hanging load etc. does not fall.

In this state, when the brake pedal 40 is depressed and the pedal switch 50 is turned on, pressurized oil is supplied into the cylinder 22 and a free fall operation is possible.

Further, in the above embodiment, the brake pedal 40 was used as the brake operating device, but the brake pedal 400
A lever may be used instead.

Next, setting of the spring forces of the brake spring 33 and the free fall spring 37 will be explained.

When the brake is released, the free fall spring 3T
It is necessary for the brake spring 33 to contract without compressing the brake spring 33, and as mentioned above, the free fall spring 37 should be compressed with a force greater than the spring force of the brake spring 33 in advance. Since it is necessary to compress the free fall spring 37, if the force for compressing the free fall spring 37 is too strong in advance, the operation of the brake pedal 40 will become heavy.

For this reason, it is necessary to minimize the force with which the free fall spring 37 is compressed in advance.

That is, considering the force acting on the rod 29 in the state shown in FIG. 3, the force that attempts to move the rod 29 in the direction of the arrow is the force due to the spring force of the brake spring 33 and the depression force of the brake pedal 40, The force that tends to move the rod 29 in the direction opposite to the direction of the arrow is the spring force of the free fall spring 37 and the tension of the brake band 10.

Therefore, if the spring force of the brake spring 33 and the spring force of the free fall spring 37 are offset, the tension of the brake band 10 can be effectively used as the depression force of the brake pedal 40.

From the above, the free fall spring 37 may be compressed in advance so that the spring forces of the brake spring 33 and the free fall spring 37 are equal in the state shown in FIG.

FIG. 6 is a graph showing the state of the spring force when the free fall spring 37 is compressed in advance with the force as described above.

In the graph, the broken line shows the spring force of the brake spring 33, and the solid line shows the spring force of the free fall spring 37.

Moreover, a-Q indicate the states shown in FIGS. 1 to 3, respectively.

That is, in state a in FIG. 1, the free fall spring 37 is compressed with a force greater than the spring force of the brake spring 33, but when the cylinder 26 is actuated and the rod 29 moves in the opposite direction to the arrow, , the brake spring 33 is compressed and the spring force of the brake spring 33 increases, but
Since the spring length of free fall spring 3γ does not change,
The spring force of the free fall spring 37 is constant.

When the rod 29 moves to the state shown in FIG. 2, the spring forces of the brake spring 33 and the free fall spring 37 become equal.

When the brake pedal 40 is depressed, that is, state C in FIG. 3, the free fall spring 37 is compressed, so the spring force of the free fall spring 37 is large, but the brake spring 33 is in an extended state, so the brake Spring 33
The spring force of is small.

When the depression force on the brake pedal 40 is reduced from this state, the free fall spring 37 gradually stretches and the spring force of the free fall spring 37 becomes smaller, and the brake spring 33 gradually contracts and the spring force of the brake spring 33 decreases. The force on the brake pedal 40 gradually decreases.

Therefore, since the depressing force on the brake pedal 40 is maximum in state C in FIG. 5, in order to reduce the maximum value of the depressing force, it is necessary to reduce the travel distance and spring constant of the brake spring 33 and the free fall spring 37. There is.

As explained above, in the winch brake device according to the present invention, even if the driver accidentally releases his or her foot or hand from the brake operating device during a free fall operation, the brake will be activated in this case. , there is no danger of suspended loads, etc. falling.

As described above, the effects of this invention are remarkable.

[Brief explanation of the drawing]

FIG. 1 is a diagram showing a winch brake device according to the present invention, FIGS. 2 to 5 are operation explanatory diagrams of the winch brake device shown in FIG. 1, and FIG. 6 is a diagram showing the winch brake device shown in FIG. 1. It is a graph for explaining the operation of the brake device. 1...Hydraulic pump, 2...Hydraulic motor, 3...Directional switching valve, 5...Operation lever, 9...Winch tram , 10...
Brake band, 12... Lever switch, 2
1... Hydraulic pump, 23... Clutch, 25... Directional switching valve, 26... Brake release cylinder, 29... Rod, 33...
... Brake spring, 37 ... Free fall spring, 38 ... Directional switching valve, 39 ...
・Rinkyu 39a...Pin, 40...
Brake pedal, 41...Pedal return spring, 4
2a... Firstborn L43... Pillar, 44.
... Lever, 45, 46 ... Adjustment bolt, 49 ... Pedal plate, 50 ...
Pedal switch, 51...Clutch switch.

Claims (1)

[Claims] 1. In a brake device used for a winch, which has a clutch provided between a winch drum and the output shaft of a hydraulic motor that drives the winch drum, and a clutch switch that releases the clutch, a brake operating device and the brake operating device are provided. a brake operation switch that turns on when the amount of operation exceeds a predetermined value; and a directional control valve that operates the hydraulic motor that extends when the clutch is released and the brake operation switch is on. a brake release cylinder, a first spring receiver fixed to the tip of the piston rod of the brake release cylinder, a second spring receiver, and movably supported by the first and second spring receivers. a first stopper fixed to the first spring receiving side end of the rond; and second and third stoppers fixed to approximately the center of the rond.
a brake spring provided between the second spring holder and the third stopper, and a spring of the brake spring provided between the first spring holder and the second stopper. a free fall spring provided in a state of being compressed beyond the force; and a first spring coupled with a pin to the brake operating device.
A pin is connected between the link, the elongated hole provided in the first link, and the second and third stoppers of the Rondo, which are rotatably supported, to which the ends of the brake band are attached. A brake device for a winch, comprising a coupled second link and a pin provided on the second link and engaged with the elongated hole.