JP2569790Y2 - Safety device for operation unit in power working machine - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a safety device for an operation unit provided in a power working machine such as a backhoe.

[0002]

2. Description of the Related Art Conventionally, for power working machines such as backhoes,
The driving section is provided with a cut-off switch for turning on and off a cut-off valve connected to a pilot valve on the hand-operated lever side, and a switch for auto deceleration for lowering the rotation of the engine. When the user is further away, the cutoff switch and the switch for auto deceleration are turned off.

[0003]

However, in the above-mentioned conventional example, when the driver leaves the driver's seat, the cutoff switch and the auto deceleration switch are turned off, so that the driver operates the cutoff switch. If the operator forgets to perform the cutting operation, the working unit malfunctions when touching the hand-operated lever unexpectedly, which is dangerous.

[0004] Further, if the auto-decel switch is forgotten to be turned off, the rotation of the engine does not decrease, so that the fuel is uneconomical.

[0005]

SUMMARY OF THE INVENTION Accordingly, the present invention provides a power working machine in which a pilot valve connected to a hand-operated lever and an electromagnetic hydraulic switching valve are connected to enable a working unit-side actuator to be freely operated. A cut-off valve that opens and closes the hydraulic circuit is provided in the middle of the hydraulic circuit that sends hydraulic oil to the pilot valve side, and a non-contact sensor that detects the presence or absence of a driver is provided on the side of the driver's seat. A controller is provided for the driver's waist located directly above the driver's seat and connected to the non-contact sensor to control the detection result, and furthermore, the controller is connected to the cutoff valve. Further, a safety device for an operating unit in a power working machine is provided, wherein a hydraulic circuit is closed by a cutoff valve when a driver is not detected.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described in detail with reference to the drawings. ing. Reference numeral 4 denotes a main boom to which a bucket boom 5 and an excavating bucket 6 are connected at the tip. Reference numeral 7 denotes a main boom actuator for vertically moving the main boom 4 up and down, 8 denotes a bucket boom actuator, 9 denotes a bucket actuator, and each of the actuators 7, 8, 9 is constituted by a hydraulic cylinder.

[0007] Reference numeral 10 denotes an engine mounted on the rear of the body 2;
Is a hood covering the engine 10. Reference numeral 12 denotes a driver's seat provided substantially at the center of the fuselage 2, which is a driver's seat.
An operation unit 13 is provided in front of the unit 12. And the driving section
13 is provided with a pair of left and right lever stands 14 and a right lever stand 15. 16 is an operation lever provided on the upper part of the left lever stand 14, 17 is an operation lever provided on the upper part of the right lever stand 15, and the left and right operation levers 16, 1
7, the turning and excavating device 3 of the body 12 can be operated. The operation section 13A is constituted by the operation levers 16 and 17 and the like.

Reference numeral 18 denotes a passage shut-off lever provided on the left lever stand 14. The passage shut-off lever 18 is provided so as to be able to move up and down so as to shut off the elevating passage 19 for the driver.

In FIG. 3, reference numeral 20 denotes a first hydraulic pump connected to the engine 10, reference numeral 21 denotes a second hydraulic pump, and reference numeral 22 denotes a third hydraulic pump.
A hydraulic pump 23 is a fourth hydraulic pump, which is an electromagnetic switching valve.
Connected to 24.

Reference numeral 25 denotes a non-contact sensor, such as an ultrasonic sensor, provided on the side of the driver's seat 12, which is disposed toward the driver's waist located immediately above the driver's seat 12. Then, it detects whether or not the driver is seated on the driver's seat 12.

Reference numeral 26 denotes a non-contact sensor 25 and a passage shut-off lever.
18 and the non-contact sensor 25 and the passage shut-off lever 18
The controller 26 is connected to a cut-off valve 28 provided on a hydraulic circuit 27 connected to the fourth hydraulic pump 23. And the cutoff valve 28 is a hydraulic circuit
27 can be opened and closed freely.

Reference numeral 29 denotes a pilot valve connected to the hand-operated levers 16 and 17, respectively. Reference numeral 30 denotes an electromagnetic hydraulic switching valve connected to the pilot valve 29. 21 and 22 are supplied to the hydraulic actuators 7, 8, and 9.

When the non-contact sensor 25 detects that the driver is not seated, a signal from the non-contact sensor 25 is input to the controller 26, and the cut-off valve 28 is turned off by the controller 26. State.

Reference numeral 31 denotes a control cylinder for changing the discharge amount of the hydraulic pumps 20, 21; 32, an auto-deceleration solenoid for rotating the engine 10 at a low speed when the power working machine is not working; It is a key stop solenoid that stops the engine 10 when it continues.

The solenoid 32 for auto deceleration and the key stop solenoid 33 are connected to the controller 26. The safety device A is connected to the non-contact sensor 25, the controller 26, the cut-off valve 28, and the like.
Is composed.

The embodiment of the present invention is constructed as described above, and the hydraulic pumps 20, 21, 22, 23 are rotated by rotating the engine 10.
To supply the high-pressure hydraulic oil of the hydraulic pumps 20, 21, 22 to the electromagnetic hydraulic switching valve 30.

In this case, since the driver is seated on the driver's seat 12, the non-contact sensor 25 detects the driver and inputs the signal to the controller 26 to turn on the cutoff valve 28. State.

When the pilot valve 29 is actuated by operating the hand-operated levers 14 and 15 in the state where the driver is seated on the driver's seat 12, the pilot pressure of the pilot valve 29 becomes electromagnetic. The high-pressure operating oil is supplied to the hydraulic actuators 7, 8, 9 by acting on the hydraulic switching valve 30. As a result, the work unit 4 operates while the body 2 turns.

When the driver gets off the driver's seat 12, the non-contact sensor 25 detects that the driver has got off the vehicle, and turns off the cutoff valve 28 via the controller 26.
Set to F state.

Therefore, the hydraulic circuit 27 is closed and the pilot valve 29 is operated even if the hand operation levers 14 and 15 are operated.
Does not operate, the electromagnetic hydraulic switching valve 30 does not operate.

Further, the controller 26 controls the auto deceleration solenoid 32 to reduce the rotation of the engine 10.

As described above, according to the above embodiment, the pilot valve 29 connected to the hand-operated levers 16 and 17 and the electromagnetic hydraulic switching valve 30 are connected so that the actuators 7 and
In a power working machine in which the hydraulic circuit 8 and 9 can be freely operated, a cut-off valve 28 for opening and closing the hydraulic circuit 27 is interposed in the hydraulic circuit 27 for sending hydraulic oil to the pilot valve 29 side, and A non-contact sensor 25 for detecting the presence or absence of a driver is provided near the
And a controller 26 for controlling the detection result by connecting to
Moreover, since the controller 26 and the cutoff valve 26 are connected to each other and the hydraulic circuit 27 is closed by the cutoff valve 28 when no driver is detected,
When the driver is not seated on the driver's seat 12, the cutoff valve is automatically turned off, and therefore, even if the operator accidentally touches the operation lever, the working unit 28 does not move with error, so that it is safe.

When the driver is not seated in the seat, the rotation of the engine is automatically reduced to a low speed to save fuel oil, which is economical and reduces noise.

If the driver is absent for a long time, the key stop solenoid (33) is operated by a timer to automatically stop the engine.

FIGS. 5 and 6 show another embodiment, and show a cabin mounting portion of a backhoe. In the figure, reference numeral 50 denotes a backhoe cabin.
Is fixed on a turning frame 51 by a fixing bolt 52.

Reference numeral 53 denotes a pipe-shaped bolt seat, which is fixed to a front step 54 provided at a front portion in the cabin 50. Reference numeral 55 denotes a lever stand on which an operation lever 56 is provided. The lower portion of the lever stand 56 is suspended from a rear step 57.

Numeral 58 is a fixing bolt, numeral 59 is a turning frame upper plate, and numeral 60 is a sealing material such as a sponge for filling a gap between the front step 54 and the rear step 57. The front step 54 and the rear step 57 constitute an inclined step 61 having a high front and a low rear. 62 is a driver's seat.

Therefore, according to the above-described embodiment, since the inclined steps 61 are formed in the cabin 50, it is easy to clean especially the mud accumulated in the corners inside the cabin. Because of the wide width, the feet of the operator are widened, and the function as a step can be fully utilized.

FIG. 7 shows another embodiment, and shows the structure of a hydraulic oil tank. In the figure, reference numeral 70 denotes a hydraulic oil tank, in which a return pipe 71 and a suction pipe 72 are provided, and a sub tank 73 is provided at a slightly higher position. 74 is a communication pipe, and 75 is an oil level gauge provided in the sub tank 73, which indicates an upper limit 76 and a lower limit 77. Reference numeral 78 denotes a detection sensor for detecting the oil level a, which is connected to the controller 79. Reference numeral 80 denotes a battery, and 81 denotes an oil amount alarm lamp that lights when the oil level a exceeds the upper limit 76 to issue an alarm.

Reference numeral 82 denotes an upper cover of the return pipe 71, and reference numeral 83 denotes a suction pipe.
A strainer provided on the 72 side and a strainer mounting cover 84 are provided.

FIG. 8 shows a conventional hydraulic oil tank. In the figure, reference numeral 90 denotes a hydraulic oil tank, and a float type oil level gauge 92 is fixed to a side wall 91 of the hydraulic oil tank 90. I have.

Reference numeral 93 denotes an air breather provided on the strainer mounting cover 94, reference numeral 95 denotes a return pipe, reference numeral 96 denotes a suction pipe, reference numeral 97 denotes a strainer, and the hydraulic oil tank 90 requires a space 98 therein.

Therefore, in the embodiment shown in FIG. 7, the sub-tank 73 is disposed at a position higher than the hydraulic oil tank 70, and the sub-tank 73 communicates with the sub-tank 73. Can be accurately measured.

Further, in the above configuration, the hydraulic oil tank
Since the space inside 70 is not required, the outer shape can be made small.

Further, the oil supply to the hydraulic oil tank 70 can be performed until the hydraulic oil becomes full, so that the oil supply is simple. In addition, when the amount of oil in the sub-tank 73 decreases due to oil leakage or the like, the alarm lamp or alarm buzzer can be activated, so that problems due to oil leakage can be prevented beforehand.

[0036]

According to the present invention, the cut-off valve closes the hydraulic circuit when the driver is not detected. Therefore, when the driver gets off the vehicle, the cut-off valve is turned off. It operates to shut off the hydraulic circuit on the pilot valve side, so that even if the hand-operated lever is unexpectedly operated, the working unit does not malfunction and is safe. Moreover, since the non-contact sensor is disposed toward the waist of the driver located immediately above the driver's seat, the presence or absence of the driver can be reliably detected. That is, the driver
The head may be moved frequently back and forth and left and right to check the surroundings while working, and the limbs may be moved frequently for operation, but when the driver is sitting in the driver's seat Since the driver's waist is securely held in the driver's seat, the driver's waist does not separate from the driver's seat during work, so that the presence or absence of the driver can be reliably detected. it can.

[Brief description of the drawings]

FIG. 1 is an overall side view of a power working machine equipped with the present invention.

FIG. 2 is a schematic plan view showing an operating unit of the power working machine.

FIG. 3 is a front view showing an attached state of a non-contact sensor.

FIG. 4 is an electric circuit and hydraulic circuit diagram showing an outline of the safety device according to the present invention.

FIG. 5 is a schematic plan view showing a cabin and a driving unit in the backhoe.

FIG. 6 is a sectional side view taken along the line II in FIG. 5;

FIG. 7 is a schematic sectional side view showing the inside of a hydraulic oil tank in the backhoe.

FIG. 8 is a schematic sectional side view showing the inside of a conventional hydraulic oil tank.

[Explanation of symbols]

 7 Actuator 8 Actuator 9 Actuator 12 Driver's seat 16 Hand control lever 17 Hand control lever 25 Non-contact sensor 26 Controller 27 Hydraulic circuit 28 Cut-off valve 29 Pilot valve 30 Electromagnetic hydraulic switching valve

Claims (1)

(57) [Scope of request for utility model registration] A pilot valve (29) connected to the hand-operated levers (16) and (17) and an electromagnetic hydraulic switching valve (30) connected to the actuator (7) and (8) on the working section side. , (9), a cut-off valve (28) that opens and closes the hydraulic circuit (27) in the middle of a hydraulic circuit (27) that sends hydraulic oil to the pilot valve (29).
A non-contact sensor (25) for detecting the presence or absence of a driver is provided on the side of the driver's seat (12).
And a controller (26) that is connected to the non-contact sensor (25) and controls the detection result.
6) and a cut-off valve (28), and an operating unit in a power working machine characterized in that the hydraulic circuit (27) is closed by the cut-off valve (28) when a driver is not detected. Safety equipment.