JPH092785A - Operating device for winch - Google Patents

Abstract

PURPOSE: To make an operator be sufficiently aware of the mode switching operation, so as to decrease possibilities of erroneous operation, by braking a winch drum in liaison with stop of driving of the winch drum, regardless of the operating state of a brake pedal. CONSTITUTION: Even if a selector valve 21 and a solenoid valve 23 are positioned in either position (a) or (b), a clutch cylinder 7 is communicated with a tank 16, accordingly, a clutch is on, namely, a hydraulic motor 5 and a winch drum remain connected to each other regardless of the operating state of an operating lever 3. When the operating lever 3 is in the neutral position, the selector valve 22 is held in the position (a), as a result, an oil passage 151 communicated with a pressure reducting valve 15 is communicated with the tank 16 through the selector valve 22 and a manual selector valve 20. Accordingly, brake releasing pressure of a brake cylinder 12 is made to be equal to pressure of the tank 16 regardless of the switching state of the pressure reducing valve 15, and the winch drum 6 is braked regardless of the operating state of a brake pedal 11.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a winch operating device mounted on a construction machine such as a crane.

[0002]

2. Description of the Related Art As a brake mechanism mounted on a device of this type, a positive brake that brakes a winch drum in cooperation with a depression operation of a brake pedal and a winch drum when a winch operation lever is in a neutral position, There is a negative brake that releases the braking of the winch drum when the operating lever is in the operating position, and it is possible to switch whether or not to apply the braking by the negative brake by operating a predetermined brake mode selection member. In such a mechanism, when the mode in which the braking by the negative brake is possible is selected, the winch drum is automatically braked and suspended in association with the driving stop of the winch (operation of the winch operation lever to the neutral position). Prevents accidental drop of load. On the other hand, when the mode in which the braking by the negative brake is impossible is selected, the braking of the winch drum is completely released by the loosening operation of the brake pedal, and a so-called free fall state is obtained. In order to perform the free fall, it is necessary to disengage the clutch to disconnect the hydraulic motor and the winch drum so that the braking action of the hydraulic motor does not act on the winch drum. The turning off of the clutch is generally linked with the selection operation of the mode in which the free fall is possible by the above-mentioned brake mode selection member.

If a switching operation to a free fall mode is performed while the brake pedal is not depressed, the suspended load may be inadvertently dropped at the time of the switching. Therefore, in the brake mechanism disclosed in Japanese Patent Laid-Open No. 1-145997, the mode cannot be switched to the free fall mode unless the brake pedal is depressed.

[0004]

It is common for winch operators to depress the brake pedal even when the negative brake is in operation, and the operation of depressing the brake pedal itself is a mode in which the operator can fall freely. It does not reflect the intention to switch to. For this reason, if the brake pedal is depressed to release the negative brake, the brake mode selection operation member is operated unintentionally while the brake pedal is depressed, and as a result, the brake pedal is released. Therefore, there is a risk that the suspended load will accidentally drop.

Therefore, an object of the present invention is to provide a winch operating device capable of reducing the risk of erroneous operation by making the operator fully aware of the operation of switching to the free fall mode.

[0006]

To explain with reference to FIG. 1 showing an embodiment, the invention of claim 1 is a positive brake function for braking a winch drum 6 in cooperation with a depression operation of a brake pedal 11. Further, the brake mechanism 10 having a negative brake function for braking the winch drum 6 in association with the drive stop of the winch drum 6 regardless of the operation state of the brake pedal 11, and the first mechanism in which the free fall of the winch drum 6 is impossible. And a mode selection member 20a capable of selecting a second mode capable of free fall, and braking of the winch drum 6 by a negative brake function so as to prohibit the free fall of the winch drum 6 when the first mode is selected. Winch with negative brake function to allow free fall when the second mode is selected. And brake control means 20, 22 to disable the braking of the ram 6, is applied to the operating device winch equipped with. When the first mode is switched to the second mode by the mode selection member 20a, until the confirmation operation different from the second mode selection operation is executed with the brake pedal 11 depressed. The above-described object is achieved by providing the switching holding means 7 and 23 for braking the winch drum 6 in association with the stop of the drive of the winch drum 6 regardless of the operation state of the brake pedal 11.
The invention according to claim 2 is applied to the winch operating device according to claim 1, and when the hydraulic motor 5 for driving the winch drum 6 and the drive stop of the winch drum 6 are linked, the hydraulic motor 5 is rotated in the lowering direction. The return side 5a has valve means 5b for confining the hydraulic oil, and the switching holding means 23, 7 hold the hydraulic motor 5 in which the hydraulic oil is confined and the winch drum 6 in a mutually connected state. The braking state of the winch drum 6 is continued. The invention of claim 3 is applied to the winch operating device of claim 1, and as the operation member for receiving the confirmation operation, the automatic return type operation member 32 which returns to the state before the operation by releasing the operation force is used. The invention of claim 4 is
A winch drum 6 driven by the hydraulic motor 5, a clutch 7 for switching connection and disconnection of the hydraulic motor 5 and the winch drum 6, an operating position for instructing the drive of the hydraulic motor 5, and a drive stop of the hydraulic motor 5. The operation lever 3 that can be operated to the instructed neutral position and the brake pedal 11
Positive brake function for braking the winch drum 6 in cooperation with the stepping operation of the brake pedal, and a negative brake function for braking the winch drum 6 in coordination with the operation of the operation lever 3 to the neutral position regardless of the operation state of the brake pedal 11. And a brake mechanism 10, a mode selecting member 20a capable of selecting a first mode in which the free fall of the winch drum 6 is impossible and a second mode in which the free fall is possible, and a selection of the first mode. Occasionally, the winch drum 6 is braked by the negative brake function in cooperation with the operation of the operation lever 3 to the neutral position, and when the second mode is selected and the operation lever 3 is operated to the neutral position,
Control means 20, 2 for blocking braking of the winch drum 6 by the negative brake function and for switching the clutch 7 to an off state for disconnecting the hydraulic motor 5 and the winch drum 6 from each other.
The present invention is applied to a winch operating device having Nos. 1 and 22. When the first mode is switched to the second mode by the mode selection member 20a, until the confirmation operation different from the second mode selection operation is executed with the brake pedal 11 depressed. Even if the operating lever 3 is returned to the neutral position, the clutch switching holding means 23 for holding the clutch 7 in the ON state for connecting the hydraulic motor 5 and the winch drum 6 is provided to achieve the above-mentioned object.

[0007]

According to the first aspect of the present invention, when the first mode is selected by the mode selecting member 20a, the winch drum 6 is braked by the negative brake function of the brake mechanism 10 in association with the drive stop of the winch drum 6. , Freefall is blocked. First by the mode selection member 20a
When the mode is switched to the second mode, the switching holding means 7, 23 are linked with the drive stop of the winch drum 6 until a predetermined confirmation operation is executed with the brake pedal 11 depressed. As a result, the winch drum 6 is held in a braked state, and the free fall is prevented.
In the invention of claim 2, when the driving of the winch drum 6 is stopped, the winch drum 6 is braked by the braking action of the hydraulic motor 5 in which the hydraulic oil is confined. According to the third aspect of the present invention, even when the mode selection member 20a switches the mode from the first mode to the second mode while the driving of the winch drum 6 is stopped, the brake pedal 11 is automatically stepped on. The winch drum 6 remains braked until the mold operating member 32 is operated. Since the automatic return type operation member 32 returns to the state before the operation in response to the release of the operation by the operator, the confirmed operation state continues without the operator's operation, and the switching holding means 7, contrary to the intention of the operator, The continuation of the braking state by 23 is not released. In the invention of claim 4, the mode selection member 20
When the first mode is selected by a, the winch drum 6 is braked by the negative brake function of the brake mechanism 10 in association with the drive stop of the winch drum 6, and the free fall is prevented. When the first mode is switched to the second mode by the mode selection member 20a, the operation lever 3 is returned to the neutral position until a predetermined confirmation operation is executed with the brake pedal 11 depressed. Even if the clutch switching holding means 23 holds the clutch 7 in the on state, the hydraulic motor 5 and the winch drum 6 remain connected. Therefore, if hydraulic oil is confined in the return side 5a when the hydraulic motor 5 is driven in the lowering direction, the winch drum 6 can be braked by the braking action of the hydraulic motor 5 to prevent a free fall.

[0008] In the means and means for solving the above-mentioned problems which explain the constitution of the present invention, the drawings of the embodiments are used to make the present invention easy to understand. It is not limited to.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT An embodiment of the present invention will be described below with reference to FIGS. FIG. 1 shows a main part of a winch driving hydraulic circuit in which an operating device according to the present embodiment is incorporated. 1 is a main circuit hydraulic pump, and 2 is an operating system hydraulic pump. The discharge pressure of the hydraulic pump 2 is guided to the primary side of the pair of pressure reducing valves 3a and 3b which is interlocked with the operating lever 3. When the operation lever 3 is in the neutral position shown, the pilot pressure introduced from the pressure reducing valves 3a and 3b to the control valve 4 is equal to the tank pressure, and the control valve 4 is held in the neutral position shown. In this state,
The counter balance valve 5b provided in the return-side oil passage 5a is closed when the winch driving hydraulic motor 5 is rotated in the lowering direction. As a result, the pressure oil is trapped in the return-side oil passage 5a, and rotation of the hydraulic motor 5 in the lowering direction is blocked. When the operation lever 3 is tilted from the neutral position to the right or the left in the figure, the pressure reducing valve 3a or 3b is released according to the amount of operation.
The pilot pressure output from the control valve 4 increases, and the control valve 4 switches from the neutral position to either the left or the right. As a result, the pressure oil from the hydraulic pump 1 is supplied to the hydraulic motor 5 and the hydraulic motor 5 is driven. The clutch cylinder 7 connects and disconnects the rotation transmission path from the hydraulic motor 5 to the winch drum 6. When a predetermined clutch release pressure is supplied to the clutch cylinder 7, the hydraulic motor 5 and the winch drum 6 are disengaged and the clutch is released, and when the clutch release pressure is stopped, the force of the spring 7a causes the hydraulic pressure. Motor 5
The winch drum 6 is connected to the clutch-on state.

Reference numeral 10 is a brake mechanism for braking the winch drum 6. The brake mechanism 10 includes a brake pedal 11, a brake cylinder 12, a brake band 13 wound around the winch drum 6, a link 14 for interlocking the brake cylinder 12 and the brake band 13, and a pressure reducing valve. 15 and. The brake cylinder 12 operates according to the magnitude of the brake release pressure introduced via the pressure reducing valve 15. When the brake release pressure rises, the brake cylinder 12 operates in the direction against the spring 12a, and in conjunction with this, the brake band 13 is loosened, and the braking of the winch drum 6 is released. When the brake release pressure decreases, the brake band 13 is tightly wound by the force of the spring 12a and the winch drum 6 is braked. The pressure reducing valve 15 works together with the brake pedal 11. When the brake pedal 11 is released, that is, when it is not stepped on, the oil passage 151 and the brake cylinder 12 communicate with each other, and the oil passage 152 toward the tank 16 is blocked from the brake cylinder 12. As the brake pedal 11 is stepped on, the oil passage 151 side gradually closes, and the oil passage 152 side gradually communicates. When the brake pedal 11 is stepped on by a predetermined amount or more, the oil passage 15 is applied to the brake cylinder 12.
1 is cut off so that only the brake cylinder 12 and the oil passage 152 communicate with each other. At this time, the limit switch 30 is pushed by the brake pedal 11, and its internal contact is turned on. The oil passage 152 always communicates with the tank 16.

In order to control the pressures respectively introduced into the clutch cylinder 7 and the brake mechanism 10 described above, in the hydraulic circuit of this embodiment, the manual switching valve 20, the pair of hydraulic pilot type switching valves 21, 22 and the solenoid valve are used. And 23 are provided. The manual switching valve 20 interlocks with the operation of a lever 20a provided in the operator's cab of the construction machine to move to the a position and the b position.
Switch between positions. The a position is a position where the free fall of the winch drum 6 is prohibited, and the b position is a position where the free fall is allowed. The switching valve 21 supplies the clutch release pressure to the clutch cylinder 7, and the switching valve 22 supplies the oil passage 15
The brake release pressures from 1 to the brake mechanism 10 are controlled. When the pilot pressure output from the pressure reducing valve 3a or 3b increases in conjunction with the operation of the operation lever 3, the pilot pressure is transmitted via the shuttle valve 8 to the switching valve 2
The changeover valves 21 and 22 are also changed over to the b position by being guided also to Nos. 1 and 22. When the operating lever 3 is in the neutral position, the switching valves 21, 2
2 is held in the a position. The solenoid valve 23 is switched to the b position when the solenoid portion 23a is excited by the control circuit described later, and to the a position when the solenoid portion 23a is demagnetized. The changes in the clutch release pressure and the brake release pressure depending on the switching states of the valves 20 to 23 will be described later. A pressure switch 31 that is turned on by receiving a predetermined pressure is provided in an oil passage 210 extending from the solenoid valve 23 to the switching valve 21. Reference numeral 32 is a push button switch operated when performing a free fall, and 33 is a warning light provided in the operator's cab to warn the operator that the free fall is possible.

FIG. 2 shows a control circuit for the solenoid portion 23a of the solenoid valve 23. When the push button switch 32 described above is turned on and the limit switch 30 that is interlocked with the brake pedal 11 is turned on, the relay 34 is excited and the solenoid portion 23a is excited. When the pressure switch 31 is turned on, the relays 35 and 36 are excited,
The solenoid 23a is excited and the warning lamp 33 is turned on. In addition, 37 is a power supply and 38 is a diode. As is apparent from FIG. 2, the push button switch 32 is
A push button 32a, a contact 32b that is turned on in response to a pressing operation of the push button 32a, and a spring 32c that biases the push button 32a in a direction in which the contact 32b is turned off, and is a so-called automatic reset type switch. Are configured.

Next, the operation will be described. First, when the free fall is not performed, the manual switching valve 20 is switched to the a position. In this case, the pressure oil from the hydraulic pump 2 is blocked by the manual switching valve 20, and the supply of the pressure oil to the switching valve 22 and the electromagnetic valve 23 via the manual switching valve 20 is blocked.
Further, the clutch cylinder 7 communicates with the tank 16 regardless of whether the switching valve 21 and the solenoid valve 23 are in the a position or the b position. Therefore, regardless of the operating state of the operating lever 3, the clutch is turned on, that is, the hydraulic motor 5. Winch drum 6
And remain connected. When the operation lever 3 is in the neutral position, the switching valve 22 is held at the position a, and as a result, the oil passage 151 leading to the pressure reducing valve 15 communicates with the tank 16 via the switching valve 22 and the manual switching valve 20. . Therefore, the brake release pressure of the brake cylinder 12 becomes equal to the pressure of the tank 16 regardless of the switching state of the pressure reducing valve 15, and the winch drum 6 is braked regardless of the operating state of the brake pedal 11. That is, in this state, the brake mechanism 10 functions as a negative brake, and therefore,
Even if the brake pedal 11 is released, the winch drum 6 does not fall free.

When the operation lever 3 is operated from the neutral position to the left or right while the manual switching valve 20 remains in the a position,
In response to the operation, the switching valves 21 and 22 are switched to the b position, and the pressure oil of the hydraulic pump 2 is switched to the switching valve 22 and the oil passage 151.
Through the pressure reducing valve 15. If the brake pedal 11 is not depressed at this time, the brake cylinder 12
The brake release pressure increases and the braking of the winch drum 6 is released, and in response to this, the winch drum 6 is driven by the hydraulic motor 5. When the brake pedal 11 is depressed, the pressure reducing valve 15 causes the oil passage 152 and the brake cylinder 12 to move.
And the brake cylinder 12
Thus, the winch drum 6 is braked.

When performing a free fall, the manual switching valve 20 is switched to the b position and the operating lever 3 is held at the neutral position. In this state, the discharge pressure of the hydraulic pump 2 is guided to the primary side of the switching valve 22 and the electromagnetic valve 23 via the manual switching valve 20, and the switching valve 22 is held at the a position.
The discharge pressure of the hydraulic pump 2 is guided from the oil passage 151 to the pressure reducing valve 15. At this time, if the brake pedal 11 is depressed, the pressure in the oil passage 151 is blocked by the pressure reducing valve 15,
The brake release pressure acting on the brake cylinder 12 is released to the tank 16 via the oil passage 152. Therefore, the winch drum 6 is still braked by the brake cylinder 12. When the brake pedal 11 is loosened from this state, the pressure in the oil passage 151 is guided from the pressure reducing valve 15 to the brake cylinder 12, and the braking of the winch drum 6 is released. That is, in this state, braking by the negative brake function becomes impossible. However, if the solenoid valve 23 remains held at the position a, the clutch cylinder 7 communicates with the tank 16 via the switching valve 21 and the solenoid valve 23,
As a result, the clutch-on state continues, so that the winch drum 6 brakes the hydraulic motor 5 (braking by back pressure trapped in the counterbalance valve 5b).
The winch drum 6 does not fall by the brake.

In order to release the braking action of the hydraulic motor 5 and execute the free fall, in addition to the operation of switching the manual switching valve 20 to the b position, it is necessary to switch the solenoid valve 23 to the b position. To do this, first of all, the brake pedal 1
The limit switch 30 is turned on by depressing 1, and the push button switch 32 is pushed in this state. Then, as is apparent from FIG. 2, the solenoid portion 23a of the solenoid valve 23a is excited and the solenoid valve 23 is switched to the b position. Solenoid valve 23
Is switched to the b position, the discharge pressure of the hydraulic pump 2 output from the manual switching valve 20 is guided to the clutch cylinder 7 via the solenoid valve 23 and the switching valve 21, and the clutch is turned off. This enables free fall. When the pressure rises in the oil passage 210, the pressure switch 31 is turned on, and in response to this, the warning lamp 33 is turned on. Since the pressure switch 31 is kept on even when the push button switch 32 is released, it is not necessary to operate the push button switch 32 after the free fall is possible. If the clutch release pressure for the clutch cylinder 7 is lost for some reason, such as when the engine that drives the hydraulic pump 2 is stopped in the free fall possible state, the pressure switch 31 is turned off and the electromagnetic switch is turned off. Valve 23
Returns to the a position. In this case, even if the manually operated valve 20 remains switched to the b position, the brake pedal 11
It is safe because the free fall does not occur unless the stepping on and the operation of the push button switch 32 are performed at the same time.

Even when the manual switching valve 20 is in the b position, when the operating lever 3 is operated to switch the switching valves 21, 22 to the b position, the clutch cylinder 7 communicates with the tank 16 and the clutch is turned on, and The discharge pressure of the hydraulic pump 2 is guided to the pressure reducing valve 15 via the oil passage 151. Therefore,
By releasing the brake pedal 11, the braking of the winch drum 6 is released, and the winch drum 6 is driven by the hydraulic motor 5. In this case, the discharge pressure of the hydraulic pump 2 is the oil passage 2
Since the pressure switch 31 is locked in 10 and remains on, the free fall can be performed by returning the operating lever 3 to the neutral position and releasing the brake pedal 11. In order to shift from the free fall possible mode to the free fall impossible mode, it is only necessary to switch the manual switching valve 20 from the b position to the a position by the lever 20a.

In the above embodiment, the lever 20a of the manual switching valve 20 serves as a mode selection member, the manual switching valve 20 and the switching valve 22 serve as brake control means, the clutch 7 and the solenoid valve 23 serve as switching holding means, and the manual switching is carried out. The valve 20 and the switching valves 21 and 22 constitute a control means, the solenoid valve 23 constitutes a clutch switching holding means, the push button switch 32 constitutes an automatic return type operation member, and the counter balance valve 5b constitutes a valve means. Further, when the manual switching valve 20 is in the a position, it corresponds to the first mode, and when it is in the b position, it corresponds to the second mode.
The pushing operation of the push button switch 32 corresponds to the confirmation operation.

In the embodiment, braking of the winch drum 6 by the brake cylinder 12 is released when the manual switching valve 20 is switched to the b position, and then the clutch 7 is operated.
While the winch drum 6 is braked by the brake action of the hydraulic motor 5 while maintaining the connection state, the brake release pressure is supplied to the brake cylinder 12 until the push button switch 32 is turned on with the brake pedal 11 stepped on. Alternatively, the winch drum 6 may be braked by the brake cylinder 12 itself. The switching valve 20 is not limited to the manual switching. The present invention can be applied even when the clutch is turned on and off by an operation member different from the brake mode switching.

[0020]

As described above, according to the present invention,
Even if the second mode is selected by the mode selection member, unless the operator depresses the brake pedal and confirms that the operation is switching to the free fall mode, the winch drum is braked. Since the state is maintained, the hanging drop due to an erroneous operation can be prevented more than ever before. Particularly, in the inventions of claims 2 and 4, since the braking of the winch drum is continued by utilizing the braking action of the hydraulic motor, it is not necessary to add new braking means. According to the third aspect of the invention, since the confirmation operation is performed by the automatic return type operation member, it is possible to completely eliminate the possibility that the continuation of the braking state of the winch drum is released against the intention of the operator.

[Brief description of drawings]

FIG. 1 is a hydraulic circuit diagram of essential parts of a winch operating device according to an embodiment of the present invention.

FIG. 2 is a diagram showing a control circuit for a solenoid portion of the solenoid valve of FIG.

[Explanation of symbols]

 3 Winch operation lever 4 Winch control valve 5 Hydraulic motor 5a Return side oil passage 5b when rotating in the lowering direction 5b Counter balance valve 6 Winch drum 7 Clutch cylinder 10 Brake mechanism 11 Brake pedal 12 Brake cylinder 13 Brake band 15 Pressure reducing valve 20 Manual switching valve 20a Manual switching valve lever 21, 22 Switching valve 23 Solenoid valve 30 Limit switch 31 Pressure switch 32 Push button switch 33 Warning light

Claims (4)

[Claims] 1. A positive brake function for braking a winch drum in cooperation with a depression operation of a brake pedal, and
A brake mechanism having a negative brake function for braking the winch drum in cooperation with the drive stop of the winch drum regardless of the operation state of the brake pedal, and a first mode in which freefall of the winch drum is impossible, and A mode selection member capable of selecting a second mode in which the free fall is possible, and braking of the winch drum by the negative brake function in order to prohibit the free fall of the winch drum when the first mode is selected. And a brake control means for disabling the winch drum by the negative brake function to allow the free fall when the second mode is selected. Switching from the first mode to the second mode by a member When the brake pedal is depressed, the drive of the winch drum is stopped regardless of the operation state of the brake pedal until a confirmation operation different from the selection operation of the second mode is executed with the brake pedal depressed. A winch operating device comprising switching holding means for interlockingly braking the winch drum. 2. A hydraulic motor for driving the winch drum, and valve means for confining hydraulic oil on a return side when the hydraulic motor is rotated in a lowering direction in cooperation with driving stop of the winch drum. The switching holding means holds the hydraulic motor in which the hydraulic oil is confined and the winch drum in a state of being connected to each other, and continues the braking state of the winch drum. The described winch operating device. 3. An operation member for receiving the confirmation operation,
2. The winch operating device according to claim 1, wherein an automatic return type operating member that returns to a state before the operation by releasing the operating force is used. 4. A winch drum driven by a hydraulic motor, a clutch for switching connection and disconnection between the hydraulic motor and the winch drum, an operating position for instructing driving of the hydraulic motor, and driving of the hydraulic motor. An operation lever that can be operated to a neutral position to instruct a stop, a positive brake function that brakes the winch drum in cooperation with the depression operation of the brake pedal, and the neutral position of the operation lever regardless of the operation state of the brake pedal. Brake mechanism having a negative brake function for braking the winch drum in cooperation with the operation of the winch drum, and selection of a first mode in which the freefall of the winch drum is impossible and a second mode in which the freefall is possible An operable mode selection member, and the operation lever when selecting the first mode In a state where the winch drum is braked by the negative brake function in association with the operation to the neutral position, the second mode is selected, and the operation lever is operated to the neutral position, the negative brake is operated. A winch operating device comprising a control means for preventing braking of the winch drum by a function and switching the clutch to an off state for disconnecting the hydraulic motor and the winch drum. When the mode is switched to the second mode, the operation lever is moved to the neutral position until a confirmation operation different from the selection operation of the second mode is executed with the brake pedal depressed. Even if the clutch is returned, the clutch is held in the ON state for connecting the hydraulic motor and the winch drum. Operating device winch, characterized in that a latching switching holding means.