KR100593696B1 - Safety device for coupling a working tool to a construction machine - Google Patents

Abstract

The present invention relates to a safety tool coupling safety device for a construction machine that detects and alerts whether the front coupling pin and the movable hook are coupled when the working tool is replaced with a clamp attached to the arm tip of the construction machine. An operation mode selection and display unit 10 for selecting and displaying; A release / combination mode display unit 20 for displaying a release mode and a combined mode according to the selection of the release mode and the combined mode; A valve direction switching unit 30 for switching the direction of hydraulic pressure applied to the hydraulic cylinder 50 according to the release mode selection; A hydraulic cylinder 50 which receives the hydraulic pressure and engages or releases the movable hook to the front coupling pin; A coupling / releasing relay (60) for detecting the coupling and loosening of the front coupling pin by the proximity sensor installed in the movable hook to operate the release / couple mode display unit (20) or the release display and alarm unit (70); A release indication and alarm unit (70) which displays a state in which the movable hook is released from the front coupling pin and sounds an alarm; It consists of a safety solenoid part 40 to block the hydraulic passage of the hydraulic cylinder 50 in accordance with the safety mode selection and the loosening of the movable hook and the front coupling pin to detect and alarm the release and loosening of the front coupling pin and the movable hook. When hydraulic pressure leaks from the hydraulic hose, the hydraulic passage is shut off so that the movable hook is not released from the front coupling pin.

Construction machinery, excavators, work tools, buckets, couplings, hydraulic cylinders, coupling pins, movable hooks

Description

Safety device for coupling a working tool to a construction machine}             

1 is a side view of a conventional coupling device for mounting a clamp to an arm of an excavator to engage a work tool;

2 is an explanatory view illustrating an operating state of coupling a movable hook of a clamp to a front coupling pin of a construction machine working tool according to an embodiment of the present invention;

3 is a cross-sectional view showing a state in which the proximity sensor according to the present invention is installed by drilling a hole in the middle of the hook of the movable hook;

Figure 4 is a block diagram showing the configuration of the work tool coupling safety device for a construction machine according to an embodiment of the present invention,

5 is a hydraulic circuit diagram illustrating an operation in which the movable hook is released from the front engagement pin of the work tool according to the direction change of the direction change valve according to the present invention;

6 is a hydraulic circuit diagram illustrating an operation in which a movable hook is coupled to a front coupling pin of a work tool according to the home position change of the direction change valve according to the present invention;

7 is a hydraulic circuit diagram illustrating a state in which the safety solenoid of the coupling safety device according to the present invention blocks the hydraulic path of the hydraulic cylinder.

<Description of Symbols for Main Parts of Drawings>

10: Operation mode selection and display section 11a: Operation hook

11b: fixed hook 12a: front coupling pin

12b: Rear coupling pin 13: Proximity sensor

20: release / coupled mode display unit 20a: constant voltage

20b: Oscillator 30: Valve direction switching part

30a: valve relay 30b: directional valve

40: Safety solenoid part 40a: Safety relay

40b: Safety solenoid 50: Hydraulic cylinder

51: piston 60: coupling / relaxing relay

70: release indication and alarm unit 70a: constant voltage

70b: Oscillator SCR: Thyristor

BELL: Bell

The present invention relates to a safety tool coupling safety device for construction machinery, and in particular, when the working tool is replaced at the arm tip of the construction machine detects and alerts whether the front hooking pin of the working tool and the movable hook of the clamp is coupled, The present invention also relates to a safety tool coupling safety device for a construction machine which prevents construction safety accidents by preventing hydraulic tools from being leaked from the hydraulic hose during the operation.

The arm tip of an excavator, a kind of construction machine, is used to demolish a bucket or a breaker or concrete structure used to break and crush rocks, asphalt, or buildings. Working tools such as a crusher can be selectively mounted according to the use.

In order to attach and detach such a work tool quickly and simply, the clamp C is mounted on the excavator arm as shown in FIG. The clamp C is provided with a fixed hook 1 at the lower rear and a movable hook 3 pivoting about the pivot shaft 2 at the lower front, and the fixed hook 1 is placed at the rear of the work tool W. FIG. The movable hook 3 was operated by the hydraulic cylinder 4 in the state of being engaged to the coupling pin 5b so as to be hooked to the front coupling pin 5a of the work tool W.

However, such a conventional work tool coupling device has a front hooking pin (3) of the working hook (W) when the hydraulic hose leaks or a leak occurs due to a defect in the connection portion between the hydraulic cylinder and the hydraulic hose. 5a) may result in accidents leading to serious injury or death by workers working around the equipment, with the work tool falling off the arm, and also causing damage to cables or other construction equipment built around it or falling on the concrete in curing. There was a great economic loss that had to be delayed or reconstructed.

In order to prevent such an accident, in Korean Patent Publication No. 2003-30432, the movable hook installed at the lower side of the clamp is configured by a sliding method rather than a rotating method, and a safety pin for preventing the retraction of the movable hook is provided to push the movable hook. The movable hook does not retract even when no hydraulic pressure is applied to the hydraulic cylinder.

However, the related art of sliding the movable hook has a disadvantage of requiring the help of the operator because the safety pin is inserted by the operator to turn the safety pin after inserting the tool pin of the work tool by sliding the movable hook hydraulically.

Accordingly, the present invention was devised to solve the conventional problems as described above, an object of the present invention is to automatically combine the work tool on the arm of the construction machine and to automatically loosen the work tool coupling safety of the construction machine To provide a device.

It is another object of the present invention to provide a safety tool coupling safety device for a construction machine that eliminates safety accidents during operation by detecting and warning whether the front hooking pin of the working tool and the movable hook of the clamp are securely coupled.

Still another object of the present invention is to provide a safety tool coupling safety device for a construction machine, in which the hydraulic cylinder does not retract even when no hydraulic pressure is supplied to the hydraulic cylinder of the clamp so that the front coupling pin of the working tool and the movable hook of the clamp are not loosened. It is.

The work tool coupling safety device for a construction machine according to the present invention for achieving the above objects includes an operation mode selection and display unit for selecting and displaying an operation mode of a release mode, a coupling mode and a safety mode; A release / combination mode display unit for displaying a release mode and a combined mode according to the operation mode selection and the release mode and the combination mode selection of the display unit; A valve direction switching unit for switching the direction of hydraulic pressure applied to the hydraulic cylinder according to the selection of the operation mode and the release mode and the engagement mode of the display unit to the release mode and the engagement mode; A hydraulic cylinder configured to receive the hydraulic pressure from the valve direction switching unit and couple or release the movable hook to the front coupling pin; A coupling / releasing relay configured to detect the coupling and loosening of the front coupling pin by a proximity sensor installed in the movable hook to operate the release / couple mode display unit or the release display and alarm unit; A release indication and alarm unit for displaying a state in which the movable hook is released from the front coupling pin and alarming; The operation hook is released from the front coupling pin by blocking the hydraulic passage of the hydraulic cylinder by receiving the release detection signal from the coupling / release relay according to the operation mode selection and the safety mode selection of the display unit and the release of the movable hook and the front coupling pin. And it consists of a safety solenoid unit for operating the release indication and the alarm unit.

An operation mode selection and display unit of a work tool coupling safety device of a construction machine according to the present invention; a selector switch capable of selecting a release mode, a coupling mode and a safety mode; And red, yellow, and green light emitting diodes for displaying the respective modes of the selector switch.

The release / coupling mode display unit of the work tool coupling safety device of the construction machine according to the present invention causes the green light emitting diode to be repeatedly turned on and off at a predetermined cycle when the “release” mode is selected, and the green color is selected when the “coupled” mode is selected. The light emitting diode is continuously lit.

The release / coupling mode display unit of the work tool coupling safety device of a construction machine according to the present invention includes: a constant voltage unit for converting a power supply of a power supply unit into a predetermined voltage; An oscillator for generating an oscillation signal; A transistor switched according to the oscillation signal of the oscillator; And a release / coupled mode display light emitting diode that emits and turns off according to on and off switching of the transistor.

The release indication and alarm unit of the work tool coupling safety device of the construction machine according to the present invention receives a power supply of the power supply unit constant voltage outputting a constant voltage; An oscillator for outputting an oscillation signal; A transistor switched on and off according to the oscillation signal of the oscillator; A light emitting diode which is repeatedly turned on and off in accordance with on and off switching of the transistor; It is characterized by consisting of a Darlington circuit to ring the bell according to the oscillation signal of the oscillator.

A thyristor in which a safety solenoid part of a work tool coupling safety device of a construction machine according to the present invention is applied to a gate of the thruster through a fixed terminal of a coupling / unwinding relay in the operation mode selection and display mode coupling mode; A diode for applying power through a safety mode terminal to the coupling / releasing relay according to the operation mode selection and the change to the safety mode of the display unit; A safety relay turned on by receiving power through the thyristor; It is characterized by consisting of a safety solenoid to cut off the hydraulic passage of the hydraulic cylinder by receiving power through the safety relay is turned on.

Coupling safety device for a work tool of a construction machine according to the present invention detects the state in which the movable hook is pulled out of the front coupling pin in the operation mode selection and the safety mode of the display unit to block the hydraulic passage of the hydraulic cylinder to push the piston of the hydraulic cylinder It is characterized by being able to prevent the thing.

Coupling safety device for a work tool of a construction machine according to the present invention is characterized in that for installing the proximity sensor in the middle of the hook hook of the movable hook to detect the state that the movable hook is pulled out of the front coupling pin.

The work tool coupling safety device of the construction machine according to the present invention is in a triggered state in a coupled mode when power is applied from the operation mode selection and display part to the safety solenoid part so that the hydraulic passage is not blocked while the hydraulic pressure is applied to the hydraulic cylinder. It is characterized in that to be applied through the thyristor to be in a conductive state in the safe mode.

The work tool coupling safety device of a construction machine according to the present invention can switch to a safe mode when a safety relay is powered through a thyristor that is turned on in a coupled mode, and when it is switched to a safe mode, the selector switch The diode is connected to the coupling terminal in the safety terminal of the characterized in that the power is continuously supplied to the coupling / loosening relay.

The selector switch of the work tool coupling safety device of a construction machine according to the present invention is characterized in that it is returned only when it is pressed back from the coupling mode to the release mode or from the safety mode to the coupling mode or release mode.

Hereinafter, with reference to the accompanying drawings in accordance with embodiments of the present invention will be described in more detail the technical configuration of the present invention.

2 is an explanatory diagram illustrating an operating state of coupling the movable hook of the clamp to the front coupling pin of the construction machine working tool according to an embodiment of the present invention.

The work tool coupling safety device of the construction machine according to the present invention detects a state in which the movable hook 11a of the clamp C is coupled to or loosened to the front engagement pin 12a of the work tool W, and lights an alarm lamp. Ring the bell.

In order to detect the state in which the movable hook 11a is coupled to or released from the front coupling pin 12a, a hole is drilled in the hook portion of the movable hook 11a and a proximity sensor 13 is installed to clamp the ( C) detects a state in which the movable hook 11a is coupled to or released from the front coupling pin 12a of the work tool W.

The proximity sensor 13 has a cylindrical body, and a sensing unit 13a is formed on the front surface of which is coated with synthetic resin, and a screw unit 13b is formed behind the sensing unit 13a to be drilled in the movable hook 11a. It can be screwed into the screw hole.

The proximity sensor 13 is a high signal (for example, a 5V signal) as a detection signal when the movable hook 11a of the clamp C is coupled to the front engagement pin 12a of the work tool W. ", And outputs a" low signal (for example, 0V signal) "when it is released.

The coupling safety device according to the present invention turns on a "green" light emitting diode which alerts the coupling when receiving the "high signal" as the coupling detection signal, and "red" which alerts the release when the "low signal" is input as the release detection signal. "It turns on the LED and at the same time emits an alarm by the bell.

In addition, when releasing the previously coupled work tool to couple the new work tool (W) to the arm of the construction machine, the "green" light emitting diode is turned off and on repeatedly as a release alarm signal to distinguish it from the combined alarm signal. .

Coupling safety device according to the present invention is to install the switch to select the operation mode in the instrument panel of the driver's seat for the alarm operation as described above, and installs an alarm lamp that lights according to the mode selected by the driver near the instrument panel Check the selected operation mode.

Figure 4 is a block diagram showing the configuration of the work tool coupling safety device for a construction machine according to an embodiment of the present invention.

The work tool coupling safety device of a construction machine according to the present invention includes an operation mode selection and display unit 10 for selecting and displaying an operation mode of a release mode, a coupling mode, and a safety mode; A release / combination mode display unit 20 for displaying a release mode and a combined mode according to the operation mode selection and the release mode and the combination mode selection of the display unit 10; A valve direction switching unit 30 for switching the direction of hydraulic pressure applied to the hydraulic cylinder 50 to the release mode and the engagement mode according to the operation mode selection and the release mode and the engagement mode of the display unit 10; A hydraulic cylinder 50 for receiving or receiving hydraulic pressure from the valve direction switching unit 30 to couple or release the movable hook 11a to the front coupling pin 12a; Coupling / operating the release / coupling mode display unit 20 or release display and alarm unit 70 by detecting the engagement and release of the front coupling pin 12a by the proximity sensor 13 installed in the movable hook 11a. An unwinding relay 60; A release indication and alarm unit 70 which displays a state in which the movable hook 11a is released from the front coupling pin 12a and sounds an alarm; The hydraulic cylinder 50 receives the release detection signal from the coupling / releasing relay 60 according to the operation mode selection and the safety mode selection of the display unit 10 and the movable hook 11a and the front coupling pin 12a. It is composed of a safety solenoid part 40 to block the hydraulic passage of the () so that the movable hook (11a) is not released from the front coupling pin (12a) and operate the release indication and alarm unit (70).

The operation mode selection and display unit 10 is installed on the instrument panel of the driver's seat so that the construction machine driver can sit and operate the driver's seat, the selector switch (SW ₁ ) for selecting the release mode, the coupling mode and the safety mode, and the selector switch Combination of the red light emitting diode D ₁ and the selector switch SW ₁ receiving power from the power supply device PWS in accordance with the switch to the release mode of SW ₁ and displaying the release mode as “red”. A yellow light emitting diode D ₂ that receives power from the power supply PWS according to the switching to the mode and displays the coupling mode as "yellow", and according to the switching of the selector switch SW ₁ to the safe mode. It consists of a green light emitting diode (D ₃ ) receiving power from the power supply (PWS) and displaying the safety mode as "green".

Here, the selector switch (SW ₁₎ so as to prevent returning to the coupled mode or the release mode in go back to the off mode, in the selector switch (SW ₁₎ binding mode by the impact of an operation error or foreign matter from the driver's or the safe mode, When returning, use the switch to return.

The "release" mode display and the "combination" mode display of the release / combination mode display unit 20 are displayed by the green light emitting diode D ₅ , and the release display and the "release" mode display of the alarm unit 70 are displayed by the red light emitting diode. It is indicated by (D ₁₁ ), and this mark is installed on the dashboard of the driver's seat so that the driver can be easily seen. In addition, the sound alarm is ringed by the bell (BELL) of the release indication and the alarm unit 70, the sound alarm is installed in the instrument panel of the driver's seat so that the driver can hear well.

When the construction machine driver switches the selector switch SW ₁ of the operation mode selection and display unit 10 to the release mode, the power of the power supply unit PWS is supplied to the release / combination mode display unit 20.

The release / coupling mode display unit 20 includes: a constant voltage generator 20a for converting the power of the power supply unit PSW into a predetermined voltage (for example, a 5V DC voltage); An oscillator 20b for generating an oscillation signal; A transistor Q ₁ switched according to an oscillation signal of the oscillator 20b; And a release / coupled mode display light emitting diode D ₅ which emits and turns off according to the on and off switching of the transistor Q ₁ .

The constant voltage generator 20a of the release / coupled mode display unit 20 converts a power supply (for example, a 24V or 12V battery power source) of the power supply unit PSW into a 5V DC voltage and supplies the oscillator 20b.

The oscillator 20b receives power from the constant voltage regulator 20a and applies an oscillation signal to the base of the transistor Q ₁ through the diode D ₄ and the resistor R ₄ . Accordingly, the transistor Q ₁ is switched on and off according to the oscillation signal to turn on and off the current flowing in the release / coupled mode display light emitting diode D ₅ , thereby releasing / coupled mode display light emitting diode D ₅ . Denotes that the movable hook 11a is released from the front coupling pin 12a by repeatedly turning on and off according to the period of the oscillation signal.

The release / combination mode display light emitting diode D ₅ is distinguished from “unlocking display” and “safety display” by repeatedly turning on and off the green light emitting diode.

On the other hand, power is applied to the valve direction switching unit 30 through the selector switch SW ₁ switched to the release mode. The valve direction switching unit 30 has a hydraulic pressure supplied to the hydraulic cylinder 50 as the valve relay 30a is turned on as the power is applied and the valve relay 30a is turned on. It consists of a direction switching valve (30b) for switching the direction of.

The valve relay 30a supplied with power through the selector switch SW ₁ is switched to apply power to the solenoid of the direction switching valve 30b to change the direction of the direction switching valve 30b.

5 is a hydraulic circuit diagram illustrating an operation in which the movable hook is released from the front engagement pin of the work tool according to the change of direction of the direction change valve according to the present invention.

When power is applied to the solenoid of the directional valve 30b through the valve relay 30a switched to the ON state, the solenoid moves the spool so that the hydraulic pressure coming from the hydraulic pump is transferred through the "B" port. 50, the movable hook 11a is released from the front engagement pin 12a by moving the piston 51 of the hydraulic cylinder 50 to the right accordingly.

At this time, since the movable hook 11a is released from the front coupling pin 12a so that the proximity sensor 13 does not detect the coupling pin and outputs a "low" signal to the coupling / releasing relay 60, the coupling / releasing relay ( As the 60 is turned off, the common terminal COM of the coupling / releasing relay 60 is connected to the fixed terminal NC, and power is applied to the release indication and alarm unit 70.

The release display and alarm unit 70 includes a constant voltage generator 70a that receives power from the power supply unit PWS and outputs a constant voltage; An oscillator 70b for outputting an oscillation signal; A transistor (Q ₄ ) switched on and off according to the oscillation signal of the oscillator (70b); A light emitting diode (D ₁₁ ) which repeatedly turns on and off depending on the on and off switching of the transistor (Q ₄ ); It is composed of transistors Q ₅ and Q ₆ which ring the bell according to the oscillation signal of the oscillator 70b.

The constant voltage generator 70a of the release indication and alarm unit 70 receives power and outputs a constant voltage (for example, + 5V) to the oscillator 70b, and the oscillator 70b receiving the voltage outputs an oscillation signal to the diode. (D _10), and is through a resistor (R ₉₎ and outputs it to the circuit constituting the Arlington transistor (Q _5, Q _6).

An alarm bell is connected to the Darlington circuit, and when the Darlington circuit operates, the bell rings. In addition to ringing the bell, an oscillation signal output from the oscillator 70b is applied to the base of the transistor Q ₄ through the diode D ₁₀ and the resistor R ₁₀ . The light-emitting and light-off of a transistor (Q ₄₎ that are switched to the ON state and OFF state the red light-emitting diode (D ₁₁₎ "red" as is the oscillator signal applied to the base of the transistor (Q ₄₎ at a cycle of the oscillating signal Will repeat.

The driver can confirm that the movable hook 11a has escaped from the front coupling pin 12a according to the repetition of light emission and extinction of the red light emitting diode D ₁₁ . The driver who confirms that the movable hook 11a has been pulled out moves the arm of the construction machine to the new work tool W and moves the fixed hook 11b of the clamp C to the new work tool W as shown in FIG. ) Is coupled to the rear coupling pin (12b).

Then, in order to couple the movable hook 11a to the front coupling pin 12a of the work tool W, the operation mode selection and the selector switch SW ₁ of the display unit 10 are switched to the coupling mode. When the selector switch SW ₁ is switched to the coupling mode, the yellow light emitting diode D ₂ indicating the coupling mode is turned on and the power of the power supply unit PSW is connected to the coupling / releasing relay 60 as the coupling mode is switched. Although it is applied, since the "low" signal is input from the proximity sensor 13, the state of power supply to the release indication and alarm unit 70 is maintained.

However, since power is not applied to the release mode terminal and no power is applied to the valve relay 30a, power is not supplied to the solenoid of the directional valve 30b. Is in a state of. That is, the piston 51 of the hydraulic cylinder 50 is moved forward and the movable hook 11a is coupled to the front coupling pin 12a of the working tool (W).

6 is a hydraulic circuit diagram illustrating an operation in which the movable hook is coupled to the front engagement pin of the work tool according to the home position change of the directional valve.

When power is not supplied to the solenoid of the directional valve 30b, the spool is in the original position so that the hydraulic pressure supplied from the pump flows into the hydraulic cylinder 50 through the hydraulic passage L ₂ and pushes the piston 51 accordingly. The movable hook 11a is coupled to the front coupling pin 12a.

When the movable hook 11a is coupled to the front coupling pin 12a, the proximity sensor 13 detects the front coupling pin 12a and outputs a "high" signal to the coupling / releasing relay 60. The coupling / unwinding relay 60 is turned on so that the common terminal COM and the fixed terminal NO are connected so that the power supply of the power supply unit PSW is released / base of the transistor Q ₁ of the coupling mode display unit 20. Is applied to the collector of transistor Q ₁ through diode D ₆ .

The transistor Q _{1 is} supplied with power to its base, and is supplied with power to the collector through the diode D ₆ to be in a conducting state, whereby the power is coupled to the common terminal COM and the fixed terminal of the coupling / unwinding relay 60. NO), diode D ₉ and diode D ₆ are supplied to the green light emitting diode D ₅ and the collector so that the green light emitting diode D ₅ is kept lit.

When the driver switches the selector switch (SW ₁ ) from the release mode to the combined mode, the releasing display red light emitting diode (D ₁₁ ) repeatedly turns off and lights up in the released mode, and then the "high" signal of the proximity sensor 13 is engaged in the combined mode. By this, the common terminal COM of the coupling / releasing relay 60 and the fixed terminal NO are connected to turn off the red light emitting diode D ₁₁ indicating the loosening.

The driver engages the movable hook 11a to the front coupling pin 12a by turning off the red light-emitting diode D ₁₁ installed on the instrument panel and turning on the yellow light-emitting diode D ₂ indicating the coupling mode. After confirming, switch the selector switch (SW ₁ ) to safe mode.

When the selector switch SW ₁ is switched to the safe mode, the green light emitting diode D ₃ indicating the safe mode is turned on, and the power is supplied to the safety solenoid through the fixed terminal NO of the coupling / unwinding relay 60 in the coupling mode. Applied to the unit 40.

The safety solenoid part 40 includes a thyristor (SCR) in which power is applied to the gate thereof through a fixed terminal (NO) of the coupling / relaxing relay (60) in a coupling mode and brought into a conductive state; A diode (D ₇ ) for applying power through the safe mode terminal to the coupling / unwinding relay (60) in accordance with the change to the safe mode of the selector switch (SW ₁ ); A safety relay 40a that is turned on by receiving power through the thyristor SCR; It is composed of a safety solenoid 40b for blocking the hydraulic passage (L ₁ ) of the hydraulic cylinder 50 by receiving power through the safety relay 40a is turned on.

In the combined mode, the power of the power supply unit PWS is applied to the gate through the fixed terminal NO, the diode D ₉ and the resistors R ₆ and R ₇ of the coupling / releasing relay 60 to turn on. Through the thyristor (SCR) in the state can be switched to the safe mode state from the power is applied to the safety relay (40a). Here, the resistors R ₆ , R ₇ and R ₈ are divided resistors for supplying a trigger voltage to the gate of the thyristor SCR.

When switched to security mode, the selector switch, the power supply to the combining / pay-off relay 60, through the combined terminal blocks of (SW _1). However, the anode of the diode (D ₆₎ to the safety terminal of the selector switch (SW ₁₎ The cathode of the diode D ₆ is connected to the coupling terminal, so that power is continuously supplied to the coupling / relaxing relay 60.

Therefore, the "high" signal is input from the proximity sensor 13 to the coupling / unwinding relay 60, and the power supply is continuously supplied to maintain the excited state so that the common terminal COM and the fixed terminal NO are connected to each other. The terminal COM and the fixed terminal NC are disconnected.

Since power is not applied to the fixed terminal NC of the coupling / unwinding relay 60, the safety relay 40a does not operate and power is not supplied to the safety solenoid 40b.

However, when the driver switches to the safe mode from the release mode, the coupling / unwinding relay 60 through the diode D ₇ and the power applied to the safety relay 40a through the safety mode terminal of the selector switch SW ₁ . The safety relay 40a is operated by the power applied through the common terminal COM and the fixed terminal NC, and the safety solenoid 40a is operated accordingly to block the hydraulic passage of the hydraulic cylinder 50.

As such, if the hydraulic passage L ₁ is blocked while the hydraulic pressure is applied to the hydraulic cylinder 50, the hydraulic cylinder 50 may be damaged. The device is for preventing the hydraulic passage L ₁ from being blocked while being applied.

In order to check whether the thyristor SCR operates normally, the resistor R ₅ and the red light emitting diode D ₈ are inserted into the cathode terminal of the thyristor SCR to check the state of the thyristor SCR.

If the hose for supplying hydraulic pressure to the hydraulic cylinder 50 leaks while working with the construction machine, the force that the hydraulic cylinder 50 pushes the movable hook 11a is weakened, so that the movable hook 11a is moved from the front coupling pin 12a. Falling dangerous situations can occur.

When the selector switch SW ₁ is switched to the safe mode in order to prevent the dangerous situation as described above, the hydraulic passage L of the hydraulic cylinder 50 is detected by detecting the state in which the movable hook 11a is pulled out of the front coupling pin 12a. _It is possible to prevent the piston 51 of the hydraulic cylinder 50 from being pushed off by blocking ₁ ), and the operation of the safety mode will be described below.

For example, the proximity sensor 13 according to the present invention may use a high frequency oscillation type proximity sensor. In the high frequency oscillation type proximity sensor, a coil in which the inductance (L) value is changed in accordance with the approach of the metal object is formed in the sensing unit 13a. When the metal object approaches, the oscillation frequency changes, and the changed oscillation frequency is referred to as the reference frequency. In comparison with the above, when a metal object approaches a certain distance or more, a detection signal (for example, a "high" signal) is output.

Thus, the proximity sensor 13 according to the present invention is to output a detection signal in accordance with the perspective of the metal object, the proximity sensor 13 installed on the movable hook (11a) is the front coupling pin 12a is a predetermined interval (eg For example, if the distance is more than 4㎜) does not output the detection signal.

Therefore, when the distance d between the movable hook 11a and the front coupling pin 12a becomes more than a predetermined distance (for example, 4 mm), the "low" signal is output from the proximity sensor 13 so that the coupling / unwinding relay The transistor Q _{3 at} 60 is turned off.

As the transistor Q ₃ is turned off, the common terminal COM and the fixed terminal NO are disconnected, the common terminal COM and the fixed terminal NC are connected, and a power source is connected to the base of the transistor Q ₂ . It is turned on by being applied.

As the safety relay 40a is turned on, power is applied to the safety solenoid 40b so that the safety solenoid 40b blocks the hydraulic path L ₁ of the hydraulic cylinder 50.

7 is a hydraulic circuit diagram illustrating a state in which the safety solenoid of the coupling safety device according to the present invention blocks the hydraulic path of the hydraulic cylinder.

When the hydraulic pressure leaks from the hydraulic hose supplying the hydraulic pressure and the movable hook 11a is pulled out of the front coupling pin 12a so that the distance between them becomes more than a predetermined interval (for example, 4 mm), the proximity sensor 13 The "low" signal is output.

Accordingly, as described above, the transistor Q ₃ of the coupling / releasing relay 60 is turned off, and the safety is turned on by applying power to the base of the transistor Q ₂ for switching the safety relay 40a. Power is supplied to the safety solenoid 40b through the relay 40a.

When the power supply safety solenoid 40b blocks the hydraulic path L _{1 of the} hydraulic cylinder 50, the piston 51 of the hydraulic cylinder 50 is not moved.

On the other hand, when the common terminal COM and the fixed terminal NC of the coupling / unwinding relay 60 are connected, the power of the power supply unit PWS is connected to the safety mode terminal of the selector switch SW ₁ and the diode D ₇ . It is applied to the release indication and alarm unit 70 via.

The power-up release indication and alarm unit 70 sounds the bell to enable the driver hook 11a to audibly notify the driver of a dangerous situation to be pulled out of the front coupling pin 12a and at the same time, the red light emitting diode D _11. ) Turns on and off repeatedly to inform the driver of the danger situation.

As described above, according to the present invention, by detecting whether the front coupling pin of the work tool and the movable hook of the clamp are coupled, the alarm is visually and audibly alerted, and the hydraulic passage when the hydraulic pressure of the hydraulic cylinder leaks during operation of the construction machine. Blocking prevents the hook from being released from the front coupling pin to prevent the occurrence of a safety accident.

Claims (11)

An operation mode selection and display unit 10 for selecting and displaying an operation mode of a release mode, a combined mode, and a safety mode; A release / combination mode display unit 20 for displaying a selection of a release mode and a combined mode of the operation mode selection and display unit 10; A valve direction switching unit 30 for switching the direction of hydraulic pressure applied to the hydraulic cylinder 50 to the release mode and the engagement mode according to the operation mode selection and the release mode and the engagement mode of the display unit 10; A hydraulic cylinder 50 for receiving or receiving hydraulic pressure from the valve direction switching unit 30 to couple or release the movable hook 11a to the front coupling pin 12a; Coupling / operating the release / coupling mode display unit 20 or release display and alarm unit 70 by detecting the engagement and release of the front coupling pin 12a by the proximity sensor 13 installed in the movable hook 11a. An unwinding relay 60; A release indication and alarm unit 70 which displays a state in which the movable hook 11a is released from the front coupling pin 12a and sounds an alarm; The hydraulic cylinder 50 receives the release detection signal from the coupling / releasing relay 60 according to the operation mode selection and the safety mode selection of the display unit 10 and the movable hook 11a and the front coupling pin 12a. Of the construction machine, characterized in that the safety hook solenoid portion (40) for operating the release indication and alarm unit 70 to prevent the movable hook (11a) from being released from the front coupling pin (12a) by blocking the hydraulic passage of the). Work tool coupling safety device. The driving mode selection and display unit (10) according to claim 1, further comprising: a selector switch (SW ₁ ) for selecting a release mode, a combined mode, and a safety mode; Safety device coupled to the work tool of a construction machine, characterized in that consisting of red, yellow, green light emitting diodes (D ₁ , D ₂ , D ₃ ) indicating each mode of the selector switch (SW ₁ ). The green light emitting diode D ₅ is repeatedly turned on and off at regular intervals when the "release" mode is selected, and the green light is emitted when the "coupled" mode is selected. Safety tool coupling safety device for a construction machine, characterized in that the diode (D ₅ ) is constantly lit. The display device of claim 1, wherein the release / coupling mode display unit (20) includes: a constant voltage generator (20a) for converting the power of the power supply unit (PSW) into a predetermined voltage; An oscillator 20b for generating an oscillation signal; A transistor Q ₁ switched according to an oscillation signal of the oscillator 20b; Safety tool coupling safety device for a construction machine, characterized in that consisting of a light emitting diode (D ₅ ) of the release / coupling mode to light up and off according to the on and off switching of the transistor (Q ₁ ). According to claim 1, Unlock display and alarm unit 70 and the constant voltage (70a) for receiving a power supplied by the power supply unit (PWS) and outputs a constant voltage; An oscillator 70b for outputting an oscillation signal; A transistor (Q ₄ ) switched on and off according to the oscillation signal of the oscillator (70b); A light emitting diode (D ₁₁ ) which repeatedly turns on and off depending on the on and off switching of the transistor (Q ₄ ); Safety tool coupling safety device for a construction machine, characterized in that consisting of a multi-arlington circuit (Q ₅ , Q ₆ ) to ring the bell (BELL) in accordance with the oscillation signal of the oscillator (70b). The thruster (SCR) according to claim 1, wherein the safety solenoid portion (40) comprises: a thyristor (SCR) in which a power is applied to the gate of the coupling / releasing relay (60) in a coupling mode and is in a conductive state; A diode (D ₇ ) for applying power through the safety mode terminal to the coupling / releasing relay (60) according to the operation mode selection and the change to the safety mode of the display unit (10); A safety relay 40a that is turned on by receiving power through the thyristor SCR; Coupled to the work tool of a construction machine, characterized in that the safety solenoid 40b is configured to block the hydraulic passage (L ₁ ) of the hydraulic cylinder 50 by receiving power through the turn-on safety relay (40a) Ring safety device. The hydraulic passage L ₁ of the hydraulic cylinder 50 is detected by detecting the state in which the movable hook 11a is pulled out of the front coupling pin 12a in the safety mode of the operation mode selection and display unit 10. Safety tool coupling safety device for a construction machine, characterized in that to prevent the piston 51 of the hydraulic cylinder (50) is pushed off. The construction according to claim 1, characterized in that the proximity sensor (13) is drilled and installed in the middle of the hook of the movable hook (11a) to detect the state where the movable hook (11a) is pulled out of the front coupling pin (12a). Coupling safety of machine tool. According to claim ₁ , When the power is applied to the safety solenoid unit 40 from the operation mode selection and display unit 10 so that the hydraulic passage (L ₁ ) is not blocked while the hydraulic pressure is applied to the hydraulic cylinder (50), Safety device coupled to the working tool of the construction machine, characterized in that the triggered state in the engaging mode is applied through the thyristor (SCR) in the conduction state in the safe mode. According to claim 2, When the power is applied to the safety relay (40a) through the thyristor (SCR) is turned on in the combined mode to switch to the safe mode, when switching to the safe mode, Safety tool coupling safety device for a construction machine, characterized in that the power is continuously supplied to the coupling / loosening relay (60) is connected to the diode (D ₇ ) from the safety terminal of the selector switch (SW ₁ ). The safety device coupling safety device of a construction machine according to claim 2, wherein the selector switch (SW ₁ ) is pressed only when the selector switch (SW ₁ ) returns from the engaged mode to the released mode or from the safe mode to the combined mode or released mode.

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