JPH02221524A - Safety device of construction machine - Google Patents

Abstract

PURPOSE:To prevent a collision by providing detection switches at an boom, an arm and a bucket respectively, providing an electromagnetic valve in a pilot pressure circuit communicated thereto an stopping the drive thereof before the bucket interferes and collides with a cab. CONSTITUTION:Detection switches 36, 39, 37, 38 which detect, and drive, a predetermined boom inclination angle A, boom eccentric angle D, arm rotary angle B and bucket rotary angle C are provided at a sideditch drill boom 51, an arm 8' and a bucket 11' respectively. An electromagnetic valve is provided in a pilot pressure circuit which communicates a remote control valve for operating the boom, the arm and the bucket with a pilot pump. When the detection switches 36-39 detect all of the angles, the drive of the boom, the arm and the bucket is stopped by the changing operation of the electromagnetic valve. Consequently, the safety of a construction machine can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of Industrial Application This invention relates primarily to a safety device for a hydraulic excavator equipped with a trench digging boom.

Conventional technology FIG. 4 is a side view of a conventional hydraulic excavator 1 among construction machines. In FIG. 5 is the ditch digging boom of the working attachment 4, 6 is the rear boom of the ditch digging boom 5, 7 is the front boom, 8 is the arm, 9 is the idler link 10 is the bushing rod, 11 is the bucket, and 12 is the boom. Cylinder, 13 is arm cylinder, 14 is bucket cylinder, 15.16.17 is work attachment 4
Each pin joint α that forms the joint part of is the boom inclination angle,
β is the arm rotation angle, and γ is the bucket rotation angle. FIG. 5 is a plan view seen from A in FIG. 4. In the figure, 1
8 is a boom eccentric cylinder attached to the ditch digging boom 5, one is a pin joint that forms a joint between the rear boom 6 and the front boom 7, and δ is a boom eccentric angle.

Next, the configuration of the conventional hydraulic excavator 1 will be described with reference to FIGS. 1 and 2. An upper rotating body 3 is provided on the lower traveling body 2, a ditch digging boom 5 (hereinafter referred to as boom 5) is attached to the front part of the upper rotating body 3, and an arm 8, a bucket 11, etc. are sequentially connected to the tip of the boom 5. to form a working attachment 4, and a boom 5. The arm 81 and packet 11 are connected to hydraulic cylinders (12, 18, 13, 1), respectively.
4), it is mounted so that it can rotate up and down, left and right, and 2 front and rear directions. Then, the bucket 11 is attached to the hydraulic excavator 1.
A detection switch (not shown) is provided that is activated when a part of the main body approaches, for example, the cab 20 (sometimes a canopy, etc.), and when the detection switch is activated, the boom 5.
Arm 8. The driving of the bucket 11 and the like is stopped.

In addition, in FIG. 6 which is a main part operation circuit diagram of the work attachment 4, 2) is a boom valve for the boom cylinder 12, 22 is a boom eccentric valve for the boom eccentric cylinder 18,
23 is an arm valve for the arm cylinder 13, 24 is a packet valve for the bucket cylinder 14, 25.26 is a left and right traveling valve, 27 is a swing valve, 28.29 is a main pump,
30 is a pilot pump, 31.32, 33.34 are for boom elevation, boom eccentricity, and arm respectively.

This is a remote control valve for buckets. So, remote control valve 31
．． When you operate 32, 33, and 34, pilot pump 3
The pilot pressure from 0 is transferred to the pilot pressure receiving part of the boom valve 2), to the pilot pressure receiving part of the boom valve 2), to the pilot pressure receiving part of the boom eccentric valve 22, to the pilot pressure receiving part of the arm valve 23, to the pilot pressure receiving part of the bucket valve 24. Acts on the pressure receiving part. Boom valve 2). Boom eccentric valve 22. Arm valve 13. Since the bucket valve 14 is switched, pressure oil from the main pump 28, 29 is supplied to the hydraulic cylinders 12, 1.
Supplied on 8, 13 and 14. Hydraulic cylinder 12.18
, 13 and 14 are telescopically operated, so the boom 5.
Arm 8. Bucket 11 is driven.

Problems to be Solved by the Invention In a hydraulic excavator equipped with a trench digging boom, when the work attachment is driven with the boom eccentric toward the cab, the bucket may interfere with the cab and cause a collision. This accident damaged the cab and posed a danger to the driver.

An object of the present invention is to solve the above-mentioned problems and provide a safety device that stops the boom, arm removal, and bucket drive before the bucket causes an interference collision with the cab.

The first means to solve the problem is to set predetermined boom inclination angles, boom eccentric angles, and arm rotation angles for each of the ditch digging boom, arm, and bucket;
A detection switch that operates by detecting the rotation angle of the bucket is provided individually, and a solenoid valve is interposed in the pilot pressure circuit that communicates the pilot pump with the remote control valve that operates the ditch digging boom, arm, and bucket. C. When all of the above detection switches detect predetermined rotation angles, the pilot pressure circuit for the remote control valve is cut off by the switching operation of the above solenoid valve;
It is configured to stop the drive of the ditch digging boom, arm, and bucket.

Function A0 The individually installed detection switches set the safe angle at the time before the bucket interferes with the cab, that is, the preset boom inclination angle, boom eccentricity angle, arm rotation angle, and bucket rotation angle. It is set to turn on when reached.

Since the above detection switches are connected in series, the solenoid valve is energized when all the detection switches are turned on. The solenoid valve is switched from the open oil passage position to the shutoff oil passage position.

C. The pilot pressure circuit for the remote control valve is shut off as described in items A and 4 above, so the boom can be removed before the bucket interferes with the cab.

The arm and bucket stop driving.

Embodiments Hereinafter, embodiments of the present invention will be described in detail based on the drawings. FIG. 1 is a side view of a hydraulic excavator 35 equipped with a safety device according to the present invention.

In the figures, the same reference numerals are given to the same components as in the prior art. 3' is an upper revolving body 4' is a work attachment attached to the front part of the upper revolving body 3';
5° is the ditch digging boom, 8' is the arm, 11° is the bucket, and 36, 37, and 38 are the bin joints 15 and 16, respectively.
．． This is a detection switch installed near 17. In FIG. 2, which is a plan view taken from the corner of FIG. 1, 39 is a detection switch provided near the bottle coupling portion 19. FIG. 3 is a circuit diagram showing a safety device according to the present invention. In the figure, 40 is a solenoid valve, 41 is a solenoid of the solenoid valve 40, 42 is an electric circuit, 43 is a manually operated switch that is always on, 44 is a buzzer, and 45 is a power source.

Next, the configuration of the safety device according to the present invention is shown in FIGS. 1 to 3.
Let's talk about the diagram. Gutter digging boom 5' (hereinafter referred to as boom 5)
A detection switch 36° 39.37.38 is activated by detecting a predetermined boom inclination angle A, boom eccentricity angle, arm rotation angle B, and bucket rotation angle C of the arm 8'', arm 8'', and bucket 11', respectively. Separately established.On the other hand,
Boom 5゛ Arm 8′, remote control valve 31 that operates bucket 11°. A solenoid valve 40 is interposed in a pilot pressure circuit 46 that communicates the pilot pump 30 with the pilot pump 30. and the detection switch 36. ~.

39 all detect predetermined rotation angles A, ~, D, the pilot pressure circuit 46 is switched by the switching operation of the solenoid valve 40.
boom 5', arm 8', bucket 11
′ is configured to stop driving. Note that the predetermined rotation angles A, B, and C.

D can be any rotation angle in the relative angular positions of the boom 5°, the arm 8', and the bucket 11', or the rotation angle of a driving rotation, or the rotation angle with respect to a specific reference line such as horizontal or vertical. Further, instead of the rotation angle, the corresponding expansion/contraction stroke position or stroke amount of each hydraulic cylinder may be detected to operate the detection switch.

Next, the functions of the safety device according to the present invention will be described. The detection switches 36, 39, 39, 36, 39, 39, 36, 39, 36, 39, 39, 39, 39, 36, 39, 39, 36, 39, 39, 36, 39, 39, 36, 39, 39, 39, 36, 39, 36, 39, 36, 39, 36, 39, 3, 36, 39,, 36,, .
37.38 are the safety angles at the time before the bucket 11° causes an interference collision with the cab 20, that is, the boom inclination angle A, the boom eccentricity angle, and the arm rotation angle B, which are set in advance.

It is designed to turn on when the bucket rotation angle C is reached. Since the detection switches 36, 39, 37, and 38 are connected in series within the electric circuit 42, the solenoid 41 is energized when all the detection switches 36, 39, 37, and 38 are turned on.

The solenoid valve 40 is switched from the open position (L) to the shutoff oil passage position (O). Pilot pump 30 and each remote control valve 31. ~
, 34 is cut off, the remote control valves 31 . ~, 34, the boom valve 2). Boom eccentric valve 22. The arm valve 23° and the bucket valve 24 are all in the neutral position. As a result, the driving of the boom 5', the arm 8°, and the bucket 11' is stopped. At the same time, the buzzer 44 emits a beeping sound (including a beeping sound and a beeping sound whose volume is changed) to notify the driver of the above-mentioned condition. Note that when performing corresponding operations on the boom 5°, arm 8'', and bucket 11' that have stopped as described above, turn off the switch 43 in the electric circuit 42.Since the solenoid 41 is de-energized, the electromagnetic The valve 40J is returned to the open oil path position.When either the boom 5°, the arm 8', or the bucket 11' is moved, any of the detection switches 36° to 39 are also turned off.

As described above, the driving of the boom 5°, the arm 8'', and the bucket 11° can be stopped before the bucket 11° causes an interference collision with the cab 20.

Effects of the Invention In a hydraulic excavator equipped with a ditch-digging boom, when the work attachment is driven with the boom eccentric to the cab side, the bucket may interfere with and collide with the cab. This accident damaged the cab and posed a danger to the driver.

However, in the safety device according to the present invention, detection switches that are activated by detecting predetermined boom inclination angles, boom eccentric angles, arm rotation angles, and bucket rotation angles of the ditch digging boom, arm, and bucket are individually provided, and A solenoid valve is interposed in the pilot pressure circuit for the remote control valve, and when all the detection switches detect a predetermined rotation angle, the pilot pressure circuit for the remote control valve is cut off by switching the solenoid valve. Thereby, the driving of the ditch digging boom, arm, and bucket can be stopped before the bucket causes an interference collision with the cab.

Therefore, in a construction machine equipped with the safety device according to the present invention, the bucket is prevented from interfering with and colliding with a portion of the construction machine main body, thereby improving safety.

[Brief explanation of the drawing]

Fig. 1 is a side view of a hydraulic excavator equipped with a safety device according to the present invention, Fig. 2 is a plan view seen from the corner of Fig. 1,
FIG. 3 is a circuit diagram showing the safety device according to the present invention, and FIG.
5 is a side view of a conventional hydraulic excavator, FIG. 5 is a plan view seen from A in FIG. 4, and FIG. 6 is an operational circuit diagram of a main part of a conventional hydraulic excavator working attachment. 1.35 Hydraulic excavator 4.4゛ Work attachment 5.5゛ Gutter digging boom 8.8'
Arm 11.11° Bucket 12 Boom cylinder 31, ~ 36, ~ Arm cylinder Bucket cylinder Boom eccentric cylinder Cab pilot pump Remote control valve detection switch Solenoid valve and above

Claims (2)

[Claims] (1) A ditch digging boom is attached to the front part of the upper rotating body, an arm and a bucket are sequentially connected to the tip of the ditch digging boom, and the ditch digging boom, arm, and bucket are each rotatable by a hydraulic cylinder, and In a construction machine that is provided with a detection switch that is activated when the bucket approaches a part of the construction machine body, and that stops driving the boom, arm, bucket, etc. when the detection switch is activated, the ditch digging boom, the arm, Each predetermined boom inclination angle, boom eccentricity angle,
Separate detection switches are installed to detect and operate the arm rotation angle and bucket rotation angle, while a solenoid valve is installed in the pilot pressure circuit that communicates the pilot pump with the remote control valve that operates the ditch digging boom, arm, and bucket. The present invention is characterized in that when all of the above-mentioned detection switches detect a predetermined rotation angle, the pilot pressure circuit for the remote control valve is cut off by the switching operation of the solenoid valve, and the driving of the ditch digging boom, arm, and bucket is stopped. Safety equipment for construction machinery. (2) A utility model characterized in that a manually operated switch is provided in series with the detection switch in the electric circuit provided with the detection switch, and the switch is operated when all of the detection switches are activated. A safety device for construction machinery as set forth in claim 1.