JP3393821B2 - Swivel lock device for construction machinery - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention belongs to the technical field of swing lock devices for construction machines.

[0002]

2. Description of the Related Art Conventionally, construction lockers such as hydraulic excavators are provided with a swing lock device so that an upper swing body does not swing unexpectedly. FIG. 3 shows an example of a conventional swing lock device. Hereinafter, this device will be described. Figure 3
In the above, a mechanical brake 12 composed of a hydraulic cylinder 12b that presses a brake shoe 12a is provided on an output shaft (not shown) of a hydraulic motor 11 for turning drive.
The braking force of the spring of the brake 12 is larger than the maximum torque of the hydraulic motor 11 (100% or more).
It is set. The output port of the electromagnetic switching valve 13 is connected to the hydraulic pressure input port of the hydraulic cylinder 12b. The hydraulic pump 14 and the oil tank T are connected to the input port of the electromagnetic switching valve 13, and the solenoid 13a is connected to the controller 15
Is connected to the output end of.

The outputs of the swing lock switch 16 and the pressure detector 17 are connected to the input end of the controller 15. The pressure detector 17 comprises, for example, a pressure switch,
An upper swing body (not shown) is provided on the input side of the pressure switch 17.
Output oil passages 20a, 2 of the remote control valve 18 for turning the
0b is connected via a shuttle valve 19. In addition,
The pilot hydraulic pump 2 is provided on the input side of the remote control valve 18.
5. The oil tank T is connected. In addition, the oil passage 20a,
20b is connected to the pilot port of the control valve 21 of the hydraulic motor 11. Output oil passages 22a, 2 of the control valve 21
2b is connected to the input port of the hydraulic motor 11, and a relief valve 23 is connected to the oil passages 22a and 22b. A hydraulic pump 24 and an oil tank T are connected to the input port of the control valve 21.

The controller 15 outputs a solenoid current when the output of the pressure switch 17 is turned on (closed) when the lock switch 16 is off (open), and outputs a solenoid current when the pressure switch 17 is off (open). Do not output. When the lock switch is on (closed), the solenoid current is not always output. With the above configuration, the above conventional device functions as follows. That is, when the remote control valve 18 is operated with the lock switch 16 turned off (opened), pilot oil pressure appears in the oil passage 20a or the oil passage 20b, and this oil pressure is transmitted via the shuttle valve 19 to the pressure switch 1
7, and the pressure switch 17 is turned on. When the signal ON is detected, the controller 15 outputs a solenoid current to switch the electromagnetic switching valve 13 from state a to state b. As a result, the pressure oil of the hydraulic pump 14 flows to the input port of the hydraulic cylinder 12, and the brake 12 is released.

On the other hand, the pilot pressure of the oil passage 20a or 20b flows into the pilot port of the control valve 21 and the hydraulic pressure from the hydraulic pump 24 flows to the hydraulic motor 11, so that the hydraulic motor 11 rotates after the brake 12 is released. start. Next, when the lock switch 16 is turned on, the controller 15 always makes the solenoid current zero, so that the brake 12 is in the braking state. In this case, when the remote control valve 18 is operated, the hydraulic motor 11 is supplied with the hydraulic pump 24.
Although the pressure oil from the oil flows, the hydraulic motor 12 does not rotate because the brake 12 is in the braking state, and the high pressure oil in the oil passages 22a and 22b flows out from the relief valve 23 to the oil tank T.

In the above-mentioned conventional apparatus, if the lock switch 16 is turned on on a flat ground, the upper revolving structure will not rotate even if the remote control valve 18 is operated by mistake. However, when the construction machine is working on a sloping ground, the weight of the machine body and the torque due to the load are applied. Therefore, even if the lock switch 16 is turned on and the remote control valve 18 is operated, the weight of the machine body is reduced. There is a risk that the torque of the hydraulic motor 11 and the torque of the hydraulic motor 11 will be added and the braking force of the brake 12 will be equal to or greater than that of the brake, causing the aircraft to run away.

[0007]

In the above case, the escape of the airframe can be prevented by setting the braking force of the brake 12 to a sufficiently large value. However, if the braking force is increased more than necessary, the force for releasing the braking force also increases, and it is necessary to increase the diameter of the hydraulic cylinder 12 or increase the discharge pressure of the hydraulic pump 14, which is a problem. The present invention has been made against the background as described above, and an object thereof is to provide a swing lock device that does not require an excessive braking force to brake a swing structure.

[0008]

To solve the above problems, the present invention employs the following means. That is, claim 1
The described invention is a construction machine having an upper swing body,
When the swing lock device of the swing body is locked,
In a hydraulic circuit in which a turning torque is not generated in a turning motor even when a turning operation is performed, the hydraulic circuit outputs an output signal of a pressure detector for detecting an output pressure of a remote control valve for turning and an ON / OFF signal of a turning lock switch. Connected to the input side of the controller, connected so as to output the output signal of the controller to the solenoid of the electromagnetic switching valve provided in the oil passage from the pilot pump to the swing remote control valve, and the swing lock switch is turned on. When the pressure detector detects the output of the remote control valve during the operation, the controller controls the electromagnetic switching valve to shut off the oil passage between the pilot pump and the turning remote control valve. It has a feature.

According to a second aspect of the present invention, in the first aspect of the invention, the controller is configured to connect the electromagnetic passage so that when the predetermined condition is satisfied after the oil passage is shut off. It is characterized by controlling the switching valve. The predetermined condition is, for example, when a certain time has elapsed or when a predetermined time has elapsed after sounding an alarm.

[0010]

[0011]

DETAILED DESCRIPTION OF THE INVENTION FIG. 1 shows a circuit of an embodiment of the present invention. FIG. 2 shows an example of a construction machine having the upper swing body 1. Embodiments of the present invention will be described below with reference to the drawings. The same components as those described in the related art are designated by the same reference numerals and detailed description thereof will be omitted.
In FIG. 2, the upper-part turning body 1 is mounted on the traveling vehicle 2 via the turning device 3. Further, the cab 4 provided on the upper-part turning body 1 is provided with a gate lock lever 35 for confirming the entry and exit of the operator.

In FIG. 1, the output end of the controller 30 is further connected to the solenoid of the second electromagnetic switching valve 32 via the switch 31 of the gate lock lever 35. The second electromagnetic switching valve 32 is inserted in the oil passage between the input port of the remote control valve and the pilot hydraulic pump 25,
The state (b) in which the solenoid current flows is switched to the state (b), and the hydraulic pressure of the pilot hydraulic pump 25 changes to the remote control valve 18
Apply to. When the solenoid current is zero, the second electromagnetic switching valve 32 is in the state A, and the hydraulic pressure to the remote control valve is connected so as to be released. The branch oil passage 33 is connected to another work machine remote control valve. The switch 31 is turned on (closed) when the gate lock lever 35 is in the passage blocking state (in the case of the solid line in the figure), and is in the off (open) state when it is in the passable state (in the case of the dotted line in the figure). So that they are connected by electrical wiring (not shown).

The controller 30 has the following functions in addition to the functions of the controller 15 described above.
That is, when the lock switch 16 is on, the pressure detector 1
When 7 detects the pressure and the switch is turned on, the solenoid current to the second electromagnetic switching valve is made zero. Then, when a predetermined requirement is satisfied, a solenoid current is output to restore the original state. As the predetermined requirement, for example,
It is also possible to output an alarm signal for notifying an erroneous operation to an alarm device (not shown) and then output the solenoid current after a lapse of a fixed time.

The present embodiment functions as follows with the above configuration. That is, when the gate lock lever 35 is pushed down as shown by the solid line in the figure to turn on the switch 31, that is, when the operator is sitting in the driver's seat and operating, the lock switch 16 is turned on and the remote controller is operated. When the valve 18 is operated, pilot pressure appears in the oil passage 20a or 20b, and the pressure switch 17 is turned on.
At this time, the controller 30 sets the solenoid current to the second electromagnetic switching valve 32 to zero and switches from state B to state B.

As a result, the pressure oil from the pilot hydraulic pump 25 is not supplied to the remote control valve 18, and the pilot pressure in the oil passages 20a and 20b becomes zero. Therefore, the control valve 21 is in the neutral state, and the hydraulic motor 11 has the hydraulic pump 2
The supply of pressure oil from 4 is cut off, and the rotational torque of the hydraulic motor 11 becomes zero. On the other hand, since the controller 30 keeps the solenoid current of the solenoid 13a of the electromagnetic switching valve 13 to zero, the braking force of the brake 12 acts on the output shaft of the swing motor, and this braking force is more sufficient than the weight of the machine body and the torque due to the load. Since it is set to a large value, the revolving structure does not make a revolving motion even on a slope.

If the operator gives a notification of an erroneous operation, the operator returns the operation lever of the remote control valve 18 to the neutral state. After that, the controller 30 returns the output of the solenoid current to the electromagnetic switching valve 13 and the second electromagnetic switching valve to the normal state. Therefore, normal operation is possible thereafter. Also, when the operator does not return the operation lever of the remote control valve 18 to the neutral state, the above-described operation is repeated. In addition,
Gate lock lever 35 raised (dotted line in the figure)
Then, the pilot pressure from the hydraulic pump 25 is not supplied to the remote control valve 18, as in the conventional device.

Therefore, in this embodiment, even when the turning torque is generated due to its own weight on the sloping ground or when the turning torque is generated due to the load, the vehicle body can be operated without significantly increasing the braking force of the brake 12. The effect is obtained that there is no danger of a runaway and safe operation is possible.

The embodiments and examples of the present invention have been described in detail above with reference to the drawings. However, the specific configuration is not limited to these examples, and design changes within the scope not departing from the gist of the present invention. Etc. are included in the present invention. For example, the pressure detector is not limited to the pressure switch, a pressure sensor may be used, and the terminal of the gate lock switch 31 may be connected without connecting the output of the controller 30 to the terminal of the gate lock switch 31. May be connected to a power source, another switch may be inserted in the connection wiring, and the switch may be controlled.

[0019]

As described above, according to the structure of the present invention, even when the rotational torque due to its own weight or load acts, the escape of the vehicle body is prevented without applying a significant braking force to the swing brake. The effect is that you can do it.

[Brief description of drawings]

FIG. 1 shows a circuit configuration of an embodiment of the present invention.

FIG. 2 shows an arrangement of gate lock levers during operation.

FIG. 3 shows a conventional swing lock device.

[Explanation of symbols]

1 Upper revolving structure 11 Swing motor 12 Hydraulic cylinder (brake) 13 Solenoid switching valve 16 lock switch (turn lock switch) 17 Pressure switch (pressure detector) 18 Remote control valve for turning 30 controller 31 Gate lock lever switch 32 Second electromagnetic switching valve (electromagnetic switching valve) 35 Gate lock lever

Claims (2)

(57) [Claims] 1. A construction machine having an upper swing body,
When the swing lock device of the swing body is locked,
In a hydraulic circuit in which a turning torque is not generated in a turning motor even when a turning operation is performed, the hydraulic circuit outputs an output signal of a pressure detector for detecting an output pressure of a remote control valve for turning and an ON / OFF signal of a turning lock switch. Connected to the input side of the controller, connected so as to output the output signal of the controller to the solenoid of the electromagnetic switching valve provided in the oil passage from the pilot pump to the swing remote control valve, and the swing lock switch is turned on. When the pressure detector detects the output of the remote control valve during the operation, the controller controls the electromagnetic switching valve to shut off the oil passage between the pilot pump and the turning remote control valve. The swing lock device for a construction machine according to claim 1, which is characterized in that. 2. The controller according to claim 1, wherein the controller controls the electromagnetic switching valve to communicate the oil passage when a predetermined condition is satisfied after the oil passage is shut off. Swing lock device for construction machinery in Japan.