JPH075259B2 - Crane safety equipment - Google Patents

Description

[Detailed Description of the Invention] A. Field of Industrial Application The present invention is used for a crane in which the front of a crane and other fronts such as a tower front can be recombined, and main winding, auxiliary winding, and undulating rope overwinding ( The present invention relates to a safety device for a crane which detects an overwinding) and outputs an avoidance signal for stopping a corresponding winch or the like.

B. Conventional Technology FIG. 3 shows a state in which the crane front including the crane boom 2 and the crane jib 3 is assembled to the crane body 1. The main rope 4 that suspends the load with the crane boom 2
It is wound up by the main winding drum 7 and fed out. The auxiliary winding rope 5 for suspending the load by the crane jib 3 is wound up by the auxiliary winding drum 8 and fed out. The hoisting rope 6 for hoisting the crane boom 2 and the crane jib 3 is wound up and fed out by the hoisting drum 9.

This crane body 1 has an overwinding prevention device as a safety device.
31 is provided. This overwinding prevention device 31 is attached to the tip of the crane boom 2 and is a micro switch (main winding hook overwinding switch) 10 for detecting overwinding of the main winding rope 4.
And a micro switch (auxiliary winding hook over winding switch) 11 attached to the tip of the crane jib 3 for detecting over winding of the auxiliary winding rope 5, and a micro switch attached to the base of the crane boom 2 for detecting over winding of the undulating rope 6. Switch 12 (boom overwind switch) and crane front cable 13,14
4 is connected via a cable and stops the corresponding drums 7 to 9 when any of the microswitches operates. FIG. 4 shows a state in which the tower front including the tower boom 15 and the tower jib 16 is assembled to the crane body 1. . The main winding rope 4 is hung around the tower jib 16 so as to suspend the load, and the auxiliary winding rope 5 is attached to the tip of the tower jib 16 via a support frame 17 and a rope 18 rotatably attached to the upper end of the tower boom 15. The tower jib 16 is connected and wound by the rotation of the auxiliary winding drum 8 and fed out to control the angle of the tower jib 16.

In such a tower front, a micro switch (tower hook over-winding switch) 20 attached to the tip of the tower jib 16 for detecting overwinding of the main winding rope 4 and an auxiliary winding rope 5 attached to the base of the tower jib 16 are installed. Micro switch (tower jib over-winding switch) 21 to detect winding,
A micro switch (tower boom over-winding switch) 22 attached to the base of the tower boom 15 for detecting over-winding of the undulating rope 6 is provided, and these are connected to the over-winding prevention device 31 via cables 23 and 24. .

By the way, when the crane front and the tower front are recombined with each other, one of the cables 13, 14 and the cables 23, 24 should be fitted to the front to prevent overwinding.
It is necessary to connect with the switch and switch by a selection switch (not shown). Therefore, in the past, a safety mechanism against incorrect connection of cables or incorrect operation of the selection switch was introduced in JP-B-62-140
No. 74 and Japanese Utility Model Publication No. 63-16707.

FIG. 5 and FIG. 6 are diagrams conceptually showing the safety mechanism disclosed in Japanese Utility Model Publication No. 63-16707. As shown in Fig. 5, connect the cable 32 to the connector when installing the crane front.
Connect to the overwinding prevention device 31 via 33, and select switch 311
To a side. As a result, the battery 34 relays
312 is excited to close the normally open contact 312a, and the relay 313 is excited to open the normally closed contact 313a. Since the micro switch 10 is normally closed and is opened by overwinding the main winding rope 4, the relay 313 is demagnetized and the normally closed contact 313a is closed when the main winding rope 4 is overwound, and the solenoid 25 is excited to stop the main winding drum 7. The winding of the main winding rope 4 is stopped.

Here, if the selection switch 311 is mistakenly switched to the b side, the relay 312 is demagnetized because the terminal 33a of the connector 33 is opened. Therefore, the normally open contact 312a remains open, the relay 313 is not excited, and the normally closed contact 313a is closed. Therefore, the solenoid 25 is excited, the winding of the main winding rope 4 is prohibited, and the operator knows the abnormality.

As shown in FIG. 6, when the tower front is mounted, the cable 35 is connected to the overwinding prevention device 31 via the connector 36, and the selection switch 311 is switched to the b side. As a result, battery 3
By 4, the relay 312 is excited to close the normally open contact 312a, and the relay 313 is excited to open the normally closed contact 313a. Since the micro switch 20 is normally closed and opened when the main winding rope 4 is overwound, the relay 313 is demagnetized during overwinding and the normally closed contact 313 is released.
a is closed, the solenoid 25 is excited, the main winding drum 7 is stopped, and the raising of the main winding rope 4 is stopped.

Here, if the selection switch 311 is mistakenly switched to the a side, the terminal 36a of the connector 36 is opened, so the relay 3
12 degauss. Therefore, the normally open contact 312a remains open, the relay 313 is not excited, and the normally closed contact 313a is closed. Therefore, the solenoid 25 is excited, the winding of the main winding rope 4 is prohibited, and the operator knows the abnormality.

C. Problem to be Solved by the Invention However, in FIG. 5, when the terminal 33a of the connector 33 is short-circuited due to insulation deterioration, the operator mistakenly switches the selection switch 311 to the b side when mounting the crane front. The normally open contact 312a is closed and the main winding rope 4
Can be rolled up, and this safety mechanism does not work properly.

Even when the tower front is installed, the terminal 36 of the connector 36
When a is insulation deteriorated and short-circuited, the normally-open contact 312a is also closed and the safety mechanism does not function properly.

A technical problem of the present invention is to automatically switch the operation in the safety device with high reliability without performing the front selection operation by the selection switch.

D. Means for Solving the Problem A case where the present invention is applied to a crane front and a tower front will be described with reference to FIGS. 1 and 2 showing an embodiment. The safety device according to the present invention has a crane front abnormality detecting means 12 when the crane front is mounted.
Input terminal 42a (42b) for exclusive use of the crane front that is connected to A (12B) and opened at the front of the tower
And the tower front abnormality detection means 22 is connected when the tower front is installed, and the tower front dedicated input terminal 43a is opened when the crane front is installed.
And an identification terminal 43b for inputting a signal for identifying the crane front and the tower front depending on the connection state at the time of mounting the crane front and the tower front, and executing a predetermined logical operation by inputting the signals of these terminals, The above-mentioned technical problem is solved by providing the logical operation means 47 which outputs the avoidance signal for avoiding the abnormal operation detected by the abnormality detection means 12A (12B), 22 based on the logical operation result.

E. Action The logical operation means 47 is the input terminal 42a of the crane front and tower front abnormality detection means 12A (12B), 22.
(42b), 43b and the signal of the identification terminal 43a are taken in to perform a logical operation, and a signal for avoiding the operation in which the abnormality is detected is output.
In response to the avoidance signal, the crane body stops, for example, hoisting of the boom hoisting rope. According to the logical operation result,
Since the signal for avoiding the corresponding operation is output, it is not necessary for the operator to select the front with a switch or the like each time the front is replaced, and the reliability is high because the logical operation result of at least three terminal inputs is used.

It should be noted that, in the above-mentioned items D and E for explaining the configuration of the present invention, the drawings of the embodiments are used to make the present invention easy to understand, but the present invention is not limited to the embodiments.

F. Example FIG. 1 is a circuit diagram when the crane front is mounted. Third
The same parts as those in FIGS. 6 to 6 are designated by the same reference numerals for description.

40 is an overwinding prevention device, which is four signal input connectors 41
To 44, the terminal 41a of the connector 41 is connected to the common terminal of the hook overwinding switch 10, and the terminal 41b is opened. The terminal 42a of the connector 42 is connected to the common terminal of the boom overwind switch 12A, the terminal 42b is connected to the common terminal of the second boom overwind switch 12B, the terminal 43a of the connector 43 is opened, and the terminal 43b is grounded. . In addition, the connector 44
The terminal 44a is connected to the common terminal of the overload switch 51 which opens when the product of the suspension load and the working radius becomes a predetermined value or more. One fixed contact of each switch is open and the other fixed contact is grounded.

These input terminals 41a to 44a are connected to the input side of a voltage converter 46 composed of a photocoupler, and the output side thereof is address lines 47A _{1 to} 47A _{7 of a} read only memory (hereinafter ROM) 47.
Respectively connected to. ROM47 data lines 47D _{1 to} 47D
_The drivers 48A to 48F composed of transistors are connected to the driver ₆ , respectively, and the driver 48A corresponding to the address signal is used.
Drive ~ 48F.

Further, the overwinding prevention device 40 includes a signal output connector 45, a terminal 45a of which is a solenoid 53 for stopping the winding of the main winding rope 4 and a terminal 45b of which is a winding of the auxiliary winding rope 5. Each is connected to a solenoid 54 for stopping. This solenoid 54 is used to stop the hoisting of the jib undulating rope 5 when the tower front is attached. Further, the terminal 45c is connected to a solenoid 55 for stopping the lowering of the auxiliary winding rope 5. This solenoid 55 is used to stop the lowering of the jib undulating rope 5 when the tower front is attached. The terminals 45d are respectively connected to solenoids 56 for stopping the winding of the undulating rope 6. The solenoid 56 is used to stop the hoisting of the tower boom hoisting rope 6 when the tower front is attached. Further, the terminal 45e is connected to a solenoid 57 for stopping the winding of the undulating rope 6. this
57 is used to stop the lowering of the tower boom hoisting rope 6 when the tower front is attached. Furthermore, the terminal 45f is connected to a buzzer 58 that sounds when an abnormality occurs.

FIG. 2 is a circuit diagram when the tower front is attached.

The terminal 41a of the connector 41 is a common terminal of the hook overwinding switch 20, and the terminal 41b is a tower jib undulating rope (auxiliary winding rope).
5 are connected to the common terminals of the overwinding switch 21 of 5, respectively. The terminals 42a and 42b of the connector 42 are both opened, and the terminal 43a of the connector 43 is the overwound switch 2 of the tower undulating rope 6.
Connected to 2 common terminals. Further, the terminal 44a of the connector 44 is connected to the common terminal of the overload switch 51. One fixed contact of each switch is open and the other fixed contact is grounded.

By the way, as can be seen from FIGS. 1 and 2, the terminal 43b of the connector 43 is grounded when the crane front is mounted and is opened when the tower front is mounted, so that the front can be identified by the signal of the address line 47A ₆ . In addition, terminals 41b and 43a of the jib overwind switch 21 and tower boom overwind switch 22 are opened when the crane front is installed, and the boom overwind switch 12A is installed when the tower front is installed.
Since the terminals 42a and 42b of the second boom overwind switch 12B are opened, the front can also be identified by these.

In the above configuration, the terminals 42a and 42b constitute the crane front dedicated input terminal, the terminal 43a constitutes the tower front dedicated input terminal, the terminal 43b constitutes the identification terminal, and the ROM 47 constitutes the logical operation means.

In the state of FIG. 1 in which each overwind switch is closed when the crane front is installed, the address signal is “0100100”, which is normal at this time, so that the data lines 47D _{1 to} 47D ₆ have “ 000000 "is output. Therefore, any solenoid or buzzer does not operate, and the operator can operate the crane. When the main winding rope 4 is wound too much and the hook overwinding switch 10 is opened, the address signal becomes "1100100". At this time, the data line 47D ₁
Outputs "100000" to ~47D _6. This allows the driver
48A is driven, the main winding hook winding stop solenoid 53 is excited, the main winding drum 7 stops, and the winding of the main winding rope 4 stops. Similarly, when the address signal changes in accordance with the operation of each overwind switch, each data line 47D _{1 to} 47D is activated so as to excite the solenoid corresponding to the operated overwind switch.
The signal is output to D ₆ . Similarly, when the tower front is attached, each winch is stopped by exciting the solenoid corresponding to the operated overwinding switch.

Further, for example, when a wrong cable is connected to the overwinding prevention device 40, data other than the identification data `` 110 '' indicating that the crane front is mounted is input to the terminals 41b, 43a, 43b, or the terminals 42a, 42b, When data other than the identification data "111" indicating that the tower front is installed is input to 43b, it is judged as an error to drive the drivers 48A to 48F from the data lines 47D _{1 to} 47D ₆ to drive the solenoids 53 to 57. At the same time, the alarm buzzer 58 sounds.

Table 1 shows identification data when the crane front is installed, when the tower front is installed, and when an error occurs.

Also, for example, if the terminal 41b is short-circuited when mounting the crane front due to deterioration of insulation, an error will occur, and similarly, the data line 47D
₁ because ～47D ₆ to all "1" is output, the alarm buzzer with this case all the solenoids 53 through 57 is energized
58 sounds.

In this way, by connecting each cable correctly to the input terminals 41a to 44a of the overwinding prevention device 40 according to the front, the ROM4
It is possible to control the solenoid that matches the front according to the logic previously defined in 7. Therefore, a switch device for selecting the front, which is required in the related art, is unnecessary, and human error is prevented. Further, when the crane front is installed and the tower front is installed, the front is identified based on the state of at least three terminals, and the three terminals each have an abnormality, and the crane front installation and the tower front installation are erroneously identified. The probability of doing so is extremely low, and the reliability is greatly improved.

Further, in the above embodiment, the ROM 47 is used to configure the logical operation circuit, so that the number of parts is smaller than that in the case of using a relay and the like, which contributes to downsizing of the device and improvement of reliability.
Further, when the logic condition becomes more complicated, the use of the ROM 47 becomes particularly effective.

It should be noted that, in the above-described embodiment, when the crane front mounting is performed and the terminal 43b for front identification is opened under the condition that the boom overwinding switch 12A and the second boom overwinding switch 12B are operating, the ROM 47 Address signal indicates one mode when the tower front is mounted, and there is a possibility of malfunction. Therefore, in order to further improve reliability, one more identification terminal equivalent to the front identification terminal 43b may be added.

Furthermore, if the logic of the ROM 47 is as follows, it is possible to detect a short circuit fault in the system of the boom overwind switch 12A and a disconnection fault in the system of the second boom overwind switch 12B.

That is, since the boom overwinding switch 12A and the second boom overwinding switch 12B always operate in that order, it is impossible for the boom overwinding switch 12A to be short-circuited and the second boom overwinding switch 12B to be open. Therefore, the address signal of ROM47 is used to identify the error, and when an error is identified, "1" is output from the added address line to display that effect or to sound a separate buzzer with a different tone color. Then, the driver can be notified of the failure.

Table 2 shows the above logic and the operation of each solenoid as 0, 1.

Although the case where the tower front is mounted instead of the crane front has been described above, the present invention can be applied as a safety device for a crane that mounts other front attachments such as a pile driver and a ground drill in addition to the tower front.

G. Effect of the Invention According to the present invention, at least three signals from each input terminal and the identification terminal of the abnormality detection means for other fronts such as the crane front and the tower front are fetched into the logical operation means and logically operated to obtain. Since a signal that avoids the operation in which the abnormality is detected is output based on the calculated result, the operation in which the abnormality is detected can be avoided without the operator having to select the front at each front replacement. , Operability is improved and human error is prevented. Further, since the signals of at least three input terminals are logically operated and the avoidance signal is output, there is no risk of malfunction even if insulation deterioration or disconnection of one input terminal occurs, and a highly reliable device. Can be provided.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 and FIG. 2 are circuit diagrams when a crane front and a tower front are mounted in this embodiment, respectively. 3 and 4 are side views of the crane showing the configurations of the crane front and the tower front. FIG. 5 and FIG. 6 are circuit diagrams showing the concept of the conventional safety mechanism when the crane front and the tower front are mounted, respectively. 10: Main winding hook over winding switch 12A: Boom over winding switch 12B: Second boom over winding switch 20: Tower main winding hook over winding switch 21: Tower jib over winding switch 22: Tower boom over winding switch 41 to 44: Connector 41a : Crane and tower common input terminals 42a, 42b: Crane dedicated input terminals 41b, 43a: Tower dedicated input terminal 43b: Identification terminal 47: ROM (logical operation means) 47A _{1 to} 47A ₇ : Address lines 47D _{1 to} 47D ₆ : Data Lines 53-57: Solenoid, 58: Alarm buzzer

Claims (1)

[Claims] 1. A crane front abnormality detecting means is connected when the crane front is mounted, and a crane front dedicated input terminal which is opened when a front other than a crane is opened and a front abnormality detecting means when a front other than a crane is mounted. Other front dedicated input terminals that are connected and open when the crane front is installed, and an identification terminal that inputs a signal that identifies the crane front and other front depending on the connection status when the crane front and other fronts are installed. A signal for each terminal is input to execute a predetermined logical operation, and based on the result of the logical operation, an avoidance signal for avoiding the abnormal operation detected by each of the abnormality detecting means at the time of the crane front and other fronts is generated. Logical operation means to output Safety apparatus for a crane, characterized in that comprises a.