JP6131065B2 - Crane working machine safety device - Google Patents

Description

  The present invention relates to a safety device for a crane working machine including an overwinding preventing device for preventing overwinding of a hook and an overload preventing device for preventing damage or overturning of the crane working machine. In addition, although the crane working machine handled by this application is mainly mounted and used for a vehicle, it may be installed on the ground or used for a ship or a truck. In the following description, the crane working machine having the crane working machine mounted on the vehicle will be described as a safety device for the crane working machine of the present application.

  A crane working vehicle equipped with a crane working machine on a vehicle is equipped with an overwinding prevention device for preventing overwinding of a hook, and an overload prevention device for preventing damage to the crane and overturning of the vehicle. There is something.

  The overwinding prevention device overwinds the operation switching valve of various hydraulic actuators (boom telescopic cylinder, boom hoisting cylinder, winch, etc.) related to the hook overwinding when the hook reaches the overwinding state. Even when operated on the acceleration side (dangerous side), the hydraulic oil from the hydraulic pump is unloaded to the tank side so that the actuators cannot be operated to the overwinding acceleration side. On the other hand, the above-described overload prevention device can be used for various actuators related to overload when the crane work machine reaches an overload state (boom telescopic cylinder, boom hoisting cylinder, winch, etc. Even if the operation switching valve (which may include a motor) is operated to the load increase side (dangerous side), the hydraulic oil from the hydraulic pump is unloaded to the tank side so that those actuators cannot be operated to the load increase side. It is what I did.

  By the way, in this type of overwinding prevention device and overload prevention device, in order to detect that the operation switching valve of various actuators has been operated on the dangerous side, generally the movement of the spool is detected by an electric switch (limit switch). However, in the spool movement detection means comprising an electrical switch, the cost of parts is high, and electrical detection may cause disconnection, poor contact, etc. and is highly reliable. It could not be said.

On the other hand, FIG. 4 shows a hydraulic circuit of the hook overwinding prevention device of the publicly known example (FIG. 2 of Patent Document 1). An electric switch is used to detect that each operation switching valve (35, 36, 37) of various related actuators (boom telescopic cylinder 15, boom hoisting cylinder 16, winch 17) is operated to the overwinding side. Instead, the pilot valves (45 to 47) are used, and the hydraulic oil is unloaded via the pilot circuit 4B by opening and closing the pilot valves (45 to 47).

That is, in the known overwinding prevention device shown in FIG. 4 , the unloading valve 7 serving as a relief is provided in the unloading circuit 34 connecting the pump circuit 32 and the tank circuit 33, and the secondary side of the unloading valve 7 is provided. A pilot circuit 4B that opens and closes the unload valve 7 is provided between the port 7a and the tank circuit 33, and detection means (for example, FIG. 1) that detects that the hook is overwound in the pilot circuit 4B. Solenoid valve 41B that is opened by a signal from the overwinding detector 26), and operation switching valves (35, 36, 37) of various actuators (extension cylinder 15, hoisting cylinder 16, winch 17) related to overwinding. The pilot valve (45, 46, 47) that opens in conjunction with each other when it is operated to the overwinding side is provided. The overwinding side operation is an operation of extending the telescopic cylinder 15, raising the hoisting cylinder 16, raising the winch 17, etc., and performing these overwinding side operations, Each pilot valve (45, 46, 47) is opened in conjunction with the operation of the operation switching valve (35, 36, 37).

In this known overwinding prevention device (FIG. 4 ), the solenoid valve 41B is opened by a signal from an overwinding detector (for example, reference numeral 26 in FIG. 1) for detecting the hook overwinding state, and the hook overwinding is detected. Any one of the operation switching valves (35, 36, 37) of the various actuators (15, 16, 17) related to overwinding in the state (opening state of the solenoid valve 41B) is operated to the overwinding promotion side. (Or the operation is continued), the pilot valve (45 to 47) provided in the operation switching valve is opened in conjunction with the operation of the operation switching valve, and the pilot circuit 4B communicates with the tank circuit 33. (The pressure at the secondary port 7a portion of the unload valve 7 is released), thereby opening the unload valve 7 and unloading the hydraulic oil in the pump circuit 32 (overwinding acceleration side operation) Is prohibited) It has become.

Thus, in the overwinding prevention device using the pilot circuit, each operation switching valve is used to detect the overwinding increase side operation by each operation switching valve (35-37) of various actuators (15-17) related to overwinding. Since the pilot valves (45 to 47) provided in (35 to 37) are used, the detection means for the overwinding advance side operation is cheaper than the above electric switch, while the disconnection and poor contact are detected as in the electric detection. fear is advantageous cormorants have to be able to provide a highly reliable lost the like.

Japanese Patent No. 36552435 (FIG. 2)

By the way, the known example shown in FIG. 4 prohibits overwinding-up side operation by pilot hydraulic pressure (including pilot circuit 4B, solenoid valve 41B, and pilot valves 45 to 47) to prevent overwinding of the hook. However, there is no disclosure of an overload prevention device (a fall prevention device) for a crane working machine.

Accordingly, the present invention provides a hydraulic pilot system for preventing overwinding and overloading only by adding a simple pilot circuit (including a solenoid valve and a pilot valve) to the hydraulic circuit of the known example (FIG. 4 ). It was made for the purpose of achieving the above.

  The present invention has the following configuration as means for solving the above problems.

[Invention of Claim 1 of the Present Application]
In the invention of claim 1 of the present application, as in the case of claim 1 described above, it is prohibited to operate the various actuators to the overwinding promotion side while being driven by various hydraulic actuators and the hook has reached the overwinding state. Targeting a safety device for a crane working machine including a winding preventing device and an overload preventing device that prohibits the various actuators from operating on the load increasing side when the crane working machine reaches an overload state. It is.

The crane working machine safety device according to claim 1 is provided with an unloading valve in the unloading circuit connecting the pump circuit and the tank circuit in the hydraulic circuit of the crane working machine, and the hook is overwound. And an overload detection means for detecting the overload state of the crane work machine, and is provided between the secondary port of the unload valve and the tank circuit to open and close the unload valve. A pilot circuit for operation is provided.

Further, in the crane working machine safety device according to claim 1 , as the overwinding prevention device and the overload prevention device, a signal from either the overwinding detection means or the overload detection means is provided in the pilot circuit. A solenoid valve that opens upon receiving, and a pilot valve that is provided on an operation switching valve of various actuators and opens when the operation switching valve is operated on the overwinding acceleration side or the load increasing side. When the pilot valves are both open, the pilot circuit communicates with the tank circuit so that the unload valve is opened and hydraulic oil is unloaded.

Since the safety device of the crane working machine of claim 1, the boom extending and contracting operation switching valve extension operation becomes and overload increasing side of the operation in the over-winding promotion side, the valve opening when extended operation of the boom extending and contracting operation switching valve One pilot valve can be used for overwinding prevention and overload prevention, while the winding operation of the winch hoisting / lowering operation switching valve is on the overwinding increase side and overload increasing side, One pilot valve that opens when the winch hoisting / lowering operation switching valve is raised can be shared for overwinding prevention and overload prevention. As for the boom hoisting operation switching valve, the hoisting operation is on the overwinding side (some models have the overturning side on the overwinding side), and the lowering operation is on the overloading side, so one spool It is good to provide two pilot valves in the. In addition, in the model in which the overturning promotion side of the boom hoisting operation switching valve is used, a single pilot valve that opens when the boom hoisting operation switching valve is overturned can be used for overwinding prevention and overload prevention. .

The safety device of the crane working machine of claim 1, as well as perform respectively the control of the over-winding prevention and overload protection in a common pilot circuit, a pilot valve provided on the boom extending and contracting operation switch valve and the winch winding- The pilot valve provided in the lowering operation switching valve can be shared for overwinding prevention and overload prevention, respectively.

[Effect of the invention of claim 1 of the present application]
In the crane work machine safety device according to the first aspect of the present invention, the overwinding prevention and the overload prevention are controlled by a pilot-type hydraulic circuit, respectively, so that detection means for detecting the dangerous side operation of each operation switching valve ( There is an effect that the pilot valve can be made cheaper and more reliable than the electric switch .

In the crane work machine safety device according to the first aspect of the present invention, the pilot circuit, solenoid valve, and pilot valve for prohibiting each dangerous side operation of the overwinding prevention device and the overload prevention device are used for overwinding prevention and overloading. Since it is shared for load prevention, the operation of undulation is limited, but there is an effect that the number of parts can be reduced (the structure is simple and can be manufactured at low cost).

It is a working posture state figure of the crane working vehicle equipped with the safety device of the crane working machine of the embodiment of the present application. It is a control block diagram of the overwinding prevention apparatus and overload prevention apparatus with which the crane work vehicle of FIG. 1 was equipped. It is a hydraulic-circuit figure of the safety device of the crane working machine of an Example of this application. It is a hydraulic circuit diagram used for the overwinding prevention apparatus of a well-known crane working machine.

[Example]
The embodiment of the present application will be described with reference to FIGS. 1 to 3. FIG. 1 shows an embodiment in which the crane work machine safety device of the present application is applied to a crane work vehicle. In other embodiments, the crane working machine can be installed on the ground or mounted on a ship or a truck.

  The crane work vehicle shown in FIG. 1 has a crane work machine 2 mounted on a vehicle body 1 that is driven by various hydraulic actuators. The crane working machine 2 is provided with a turning post 11 on a vehicle body 1 and a telescopic boom 12 that can be extended and retracted is mounted on the turning post 11, and a hook 13 is suspended from the tip of the telescopic boom 12 to load the crane. It is comprised so that it can raise / lower.

The telescopic boom 12 is expanded / contracted by an expansion / contraction cylinder (reference numeral 15 in FIG. 3 ) built in the boom, and is also undulated by a undulation cylinder 16. The hook 13 is wound up and lowered by a winch 17 provided on the turning post 11. Pivot post 11 is caused to horizontally pivot by a turning motor indicated by reference numeral 18 in FIG. 3. The vehicle body 1 is provided with a pair of left and right outriggers 14, 14. Each of the outriggers 14 and 14 extends and retracts to the left and right with a built-in lateral slide cylinder (not shown), and can support the vehicle body 1 with jack cylinders 19A and 19B.

  On the other hand, the crane working vehicle of FIG. 1 includes a load detector 21 for detecting a load applied to the telescopic boom 12, a boom length detector 22 for detecting the length of the telescopic boom 12, and the undulation of the telescopic boom 12. A boom angle detector 23 for detecting the angle, a turning angle detector 24 (see FIG. 2) for detecting the turning angle of the turntable 11, and an outrigger extension length detector 25 (see FIG. 2) for detecting the extension length of the outrigger 14 2) and an overwinding detector (which becomes an overwinding detecting means in claims) 26 for detecting that the hook 13 has approached the boom tip portion up to a predetermined distance.

  The crane work vehicle of FIG. 1 includes an overwinding prevention device for prohibiting various actuators from operating on the overwinding acceleration side (dangerous side) when the hook 13 reaches an overwinding state, and crane operation. And an overload prevention device for prohibiting various actuators from operating on the load increasing side (dangerous side) when the machine 2 reaches an overload state.

  The overwinding prevention device generates an overwinding detection signal from the overwinding detector 26 when the hook 13 is wound up to the boom tip side until it hits the overwinding detector 26, and the overwinding detection signal As shown in FIG. 2, the boom-related operation control means 66 is controlled to prohibit the overwind danger side operation by a signal from the output means 65 of the controller 10.

  On the other hand, as shown in FIG. 2, the overload prevention device prohibits overload danger side operation from the output means 64 to the boom related operation control means 66 when the overload detection means 60 detects an overload condition. Control is performed. The overload detection means 60 is a limit moment calculation means 61 based on the detected values from the boom length detector 22, the boom angle detector 23, the turning angle detector 24, and the outrigger extension length detector 25. The calculated limit moment and the actual moment calculated by the actual moment calculation means 62 based on the detected value from the load detector 21 (which detects the load of the telescopic boom 12 received by the hoisting cylinder 16 as shown in FIG. 1) When the actual moment reaches the limit moment, the boom-related operation control means 66 is controlled by the signal from the output means 64 to prohibit the overload danger side operation. is there.

The control by the boom-related operation control unit 66 is intended to be unloaded to the tank circuit 33 side through the unload circuit 34 of working oil in the pump circuit 32 which is supplied from the hydraulic pump 30 in FIG. 3.

Although FIG. 3 shows a hydraulic circuit of the safety device of the present Ganmi施例, in the hydraulic circuit of FIG. 3, reference numeral 30 denotes a hydraulic pump, 31 is a tank, 32 hydraulic oil is supplied from the hydraulic pump 30 The pump circuit 33 is a tank circuit connected to the tank 31.

  In the hydraulic circuit of FIG. 3, the telescopic cylinder 15 is expanded and contracted by operating the boom telescopic operation switching valve 35, the hoisting cylinder 16 is hoisted by operating the boom hoisting operation switching valve 36, and the winch 17 is hoisted and unwound. The operation switching valve 37 is turned up and down, the turning motor 18 is turned left and right by the operation of the turning operation switching valve 38, and the left and right jack cylinders 19A, 19B are respectively connected to the jack expansion / contraction operation switching valves 39A, It can be expanded and contracted by the operation of 39B.

  Each of the operation switching valves (35, 36, 37, 38, 39A, 39B) is a three-position switching valve that is manually operated. Each of these operation switching valves is such that the central valve chamber is in a neutral position and the left and right valve chambers supply hydraulic oil to the actuators in opposite directions.

An unload circuit 34 is interposed between the pump circuit 32 and the tank circuit 33. In the unload circuit 34, an unload valve 7 that is opened and closed by a pilot pressure from a pilot circuit 4A described later is provided. The unload valve 7 is a relief / unload valve. The unload valve 7 is provided with a primary port connected to the pump circuit 32 and a secondary port 7a connected to a pilot circuit 4A described later. It has been.

  The crane work machine safety device according to this embodiment includes an overwinding prevention device for the hook 13 and an overload prevention device for the crane work machine 2, and a pump circuit 32 in the hydraulic circuit of the crane work machine 2. The unloading valve 7 is provided in the unloading circuit 34 connecting the tank circuit 33 and the overwinding detecting means 26 (FIGS. 1 and 2) for detecting the overwinding state of the hook 13, and the crane work machine 2 And an overload detecting means 60 (FIG. 2) for detecting the overload state of the engine, and a pilot which is interposed between the secondary port 7a of the unload valve 7 and the tank circuit 33 and opens and closes the unload valve 7. A circuit 4A is provided. In this embodiment, there is only one pilot circuit 4A.

Further, in the safety device of the actual施例in FIG. 3, as for the control of the over-winding prevention apparatus and overload prevention device, in one pilot circuit 4A, both the over-winding detector 26 of the overload detection means 60 Solenoid valve 41A that opens in response to a signal from either of them, and each pilot valve (45-47) that operates in conjunction with each operation switching valve (35-37) of each actuator (15-17). Provided.

When either one of the overwinding detector 26 and the overload detection means 60 generates a detection signal, the solenoid valve 41A opens with the solenoid de-energized (the state shown in FIG. 3 ). When both the detector 26 and the overload detection means 60 are in the non-detection state (non-overwinding state and non-overloading state), the solenoid is excited and the valve-closed state is maintained.

  On the other hand, the operation switching valves 35, 36, 37 of various actuators (expanding cylinder 15, hoisting cylinder 16, winch 17) that perform both overwinding-related operations and overload-related operations are provided with the respective operation switching valves 35, 36. , 37 is provided with pilot valves 45, 46, 47 that open when operated on the overwinding side or the load increasing side. The pilot valve 45 provided in the boom extension / contraction operation switching valve 35 is opened when the boom extension / contraction operation switching valve 35 is operated to the boom extension side, and the pilot valve 46 provided in the boom raising / lowering operation switching valve 36. Is a valve that opens both when the boom raising / lowering operation switching valve 36 is operated on both the boom raising side (on the overwinding side) and the boom lying down side (on the load side). The up / down operation switching valve 37 opens when operated to the winch winding side.

Then, in the safety device of the actual施例in FIG. 3, and opens the solenoid valve 41A is at a overload state or an over wound state, the over-winding-related operations in that state (or overload related operations) When any one of the operation switching valves (35 to 37) of the various actuators (15 to 17) is operated to the overwinding promotion side or the load increasing side, one of the pilot valves (45 to 47) opens. When the pilot circuit 4A communicates with the tank circuit 33, the unload valve 7 is opened to unload the hydraulic oil.

Thus, the safety device of this embodiment, since the the over-winding preventing overload preventing to control hydraulic circuit of each pilot-detects the dangerous operation of the operation switch valve (35-37) The detection means (pilot valves 45 to 47) can be made inexpensive and highly reliable.

In the safety device of this embodiment, overwinding prevention and overload prevention are controlled by a pilot-type hydraulic circuit, respectively, and the pilot circuit 4A, solenoid valve 41A, and pilot valves 45-47 are overwound. Since it is shared by the means for prohibiting each dangerous side operation of the prevention device and overload prevention device, although the operation of undulation is limited, the number of parts can be reduced (the structure is simple and can be manufactured at low cost). .

  2 is a work machine, 4A is a pilot circuit, 7 is an unloading valve, 7a is a secondary port, 15 is a telescopic cylinder (actuator), 16 is a hoisting cylinder (actuator), 17 is a winch (actuator), and 21 is a load detection (Load detection means), 30 is a hydraulic pump, 31 is a tank, 32 is a pump circuit, 33 is a tank circuit, 34 is an unload circuit, 35 is a boom telescopic operation switching valve, 36 is a boom hoisting operation switching valve, 37 is A winch hoisting / lowering operation switching valve, 41A is a solenoid valve, 45 to 47 are pilot valves, and 60 is an overload detecting means.

Claims (1)

Over-winding prevention device that prohibits operating the above-mentioned various actuators to the overwinding promotion side when the hook is overwound and driven by various hydraulic actuators, and the crane work machine has reached an overload state A crane working machine safety device comprising an overload prevention device for prohibiting the operation of the various actuators on the load increasing side,
An unloading valve is provided in the unloading circuit connecting the pump circuit and the tank circuit in the hydraulic circuit of the crane working machine.
An overwinding detecting means for detecting an overwinding state of the hook; and an overload detecting means for detecting an overloading state of the crane work machine,
A pilot circuit interposed between the secondary port of the unload valve and the tank circuit for opening and closing the unload valve;
As the overwinding prevention device and the overload prevention device, a solenoid valve that opens in response to a signal from either the overwinding detection means or the overload detection means in the pilot circuit and the operation of the various actuators. A pilot valve that is provided in the switching valve and opens when the operation switching valve is operated to the overwinding acceleration side or the load increasing side, and when both the solenoid valve and the pilot valve are open The pilot circuit communicates with the tank circuit so that the unload valve is opened and hydraulic fluid is unloaded.
A crane working machine safety device.

Images