JPH02265899A - Safety device of crane - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

DETAILED DESCRIPTION OF THE INVENTION A. Industrial Field of Application The present invention is used for lanes where the crane front and other fronts such as tower fronts can be recombined, and are used for overwinding of main hoisting, auxiliary hoisting, and undulating ropes. The present invention relates to a crane safety device that outputs an avoidance signal that detects a person (hereinafter referred to as a fitter) and stops the corresponding winch.

B. Prior Art FIG. 3 shows a state in which a crane front consisting of a crane boom 2, a crane jib 3, etc. is assembled to a crane body 1. The main lobe 4 that suspends the load with the crane boom 2 is
Winding is carried out by the main winding drum 7.

It is brought out. The auxiliary hoisting rope 5 on which the load is suspended by the crane jib 3 is wound up and let out by the auxiliary hoisting drum 8.

A hoisting lobe 6 for hoisting the crane boom 2 and crane jib 3 is wound up and let out by a hoisting drum 9.

The crane body 1 is provided with an overwind prevention device 31 as a safety device. This fittest prevention device 31 includes a microswitch (main hoist hook fittest switch) 10 that is attached to the tip of the crane boom 2 and detects the withdrawal of the main hoisting rope 4, and a microswitch (main hoisting hook fittest switch) that is attached to the tip of the crane jib 3 and detects the withdrawal of the auxiliary hoisting rope 5. A microswitch (auxiliary hook spiral switch) 11 that detects a person leaving the crane, and a microswitch 1 that is attached to the base of the crane boom 2 and detects a person leaving the undulating rope 6.
2 (boom suitability switch) are connected via crane front cables 13 and 14, and when any one of the microswitches is activated, the corresponding drums 7 to 9 are stopped. The figure shows the tower front assembled to the crane body 1. The main hoisting rope 4 is hung around a tower jib 16 to hang a load, and the auxiliary hoisting rope 5 is connected to a support frame 17 and a rope 18 rotatably attached to the upper end of the tower boom 15.
It is connected to the tip of the tower jib 16 via the auxiliary winding drum 8, and is wound up and let out by the rotation of the auxiliary winding drum 8 to control the angle of the tower jib 16.

In such a tower front, tower jib 16
A microswitch (tower hook fitter switch) 20 is attached to the tip of the tower jib 16 and detects the withdrawal of the main hoisting rope 4, and a microswitch (tower jib fitter switch) is attached to the base of the tower jib 16 to detect overwinding of the auxiliary hoisting rope 5.
21 and a microswitch (tower boom suitable switch) 22 which is attached to the base of the tower boom 15 and detects the withdrawal of the levitation rope 6, and these are connected to the cable 2.
3.24 to the anti-vortex device 31.

By the way, when recombining the crane front and the tower front, the cable 13.
14 and cables 23 and 24 to the swirl prevention device 31, and it is necessary to switch using a selection switch (not shown). Therefore, safety mechanisms against incorrect connection of cables and incorrect operation of selection switches have been proposed in Japanese Utility Model Publication No. 62-14.074 and Publication No. 63-16707.
It is disclosed in the publication No.

5 and 6 are diagrams conceptually showing the safety mechanism disclosed in Japanese Utility Model Publication No. 16707/1983. As shown in Figure 5, when installing the crane front, the cable 32
is connected to the swirl prevention device 31 via the connector 33, and the selection switch 311 is switched to the a side. As a result, the relay 312 is energized by the battery 34 and the normally closed contact 312
a closes, relay 313 is energized and normally closed contact 313a
opens. Since the microswitch 10 is normally closed and opened when the main winding rope 4 leaves, the relay 313 is activated at the appropriate time.
is demagnetized, the normally closed contact 313a closes, and the solenoid 25
is excited, the main winding drum 7 is stopped, and the winding of the main winding rope 4 is stopped.

If the 1 selection switch 311 is mistakenly switched to the b side, the relay 312 is demagnetized because the terminal 33a of the connector 33 is open. Therefore, the normally closed contact 31
2a remains open and relay 313 is not energized,
Normally closed contact 313a is closed. Therefore, the solenoid 25 is energized and the main hoisting rope 4 is prohibited from hoisting.
The operator learns of the abnormality.

As shown in FIG. 6, when installing the tower front, the cable 35 is connected to the swirl prevention device 31 via the connector 36, and the selection switch 311 is switched to the b side. As a result,
The relay 312 is energized by the battery 34 to close the normally closed contact 312a, and the relay 313 is energized to close the normally closed contact 3.
13a opens.

Since the microswitch 20 is normally closed and opened when the main winding rope 4 leaves the main winding rope 4, the relay 313 is demagnetized at the appropriate time, the normally closed contact 313a is closed, the solenoid 25 is energized, the main winding drum 7 is stopped, and the main winding drum 7 is stopped. The raising of the winding rope 4 is stopped.

here,! ! If the selection switch 311 is mistakenly switched to the a side, the relay 312 is demagnetized because the terminal 36a of the connector 36 is open. Therefore, the normally closed contact 31
2a remains open and relay 313 is not energized,
Normally closed contact 313a is closed. Therefore, the solenoid 25 is energized and hoisting of the main hoisting rope 4 is prohibited.
The operator learns of the abnormality.

C1 Problem to be Solved by the Invention However, in FIG.
If the insulation of a is deteriorated and short-circuited, the normally open contact 312a will close even if the operator accidentally switches the selection switch 311 to the b side when installing the crane front, and the main hoisting rope 4 will not be able to be hoisted. , this safety mechanism does not function properly.

Even when the tower front is installed, if the terminal 36a of the connector 36 is short-circuited due to insulation deterioration, the normally open contact 31
2a closes and the safety mechanism does not function properly.

A technical object of the present invention is to automatically switch operations within a safety device with high reliability without performing a front selection operation using a selection switch.

A case in which 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 of the present invention. The safety device according to the present invention is sometimes installed at the crane front.
Crane front dedicated input terminal 42a is connected to 2A (12B) and is opened during tower front operation.
(42b), the tower front abnormality detection means 22 is sometimes connected to the tower front installation, and the tower front dedicated input terminal 43a, which is sometimes open when the crane front installation is connected, and the crane front and tower front installation are connected at the same time. The identification terminal 43b inputs a signal for identifying the crane front and the tower front, and the abnormality detection means 12A (12B ), and logical operation means 47 that outputs an avoidance signal to avoid the abnormal operation detected in 22, the above-mentioned technical problem is solved.

80 action logic calculation means 47 is abnormality detection means 12A (12B) for crane front and tower front.

22 input terminals 42a (42b), 4.3b,
It takes in the signal of the identification terminal 43a, performs a logical operation, and outputs a signal that avoids the detected abnormal operation.

Upon receiving this avoidance signal, the crane body, for example, stops hoisting the boom hoisting rope. Depending on the logical operation result,
Since a signal is output to avoid the corresponding operation, there is no need for the operator to select the front using a switch each time the front is replaced, and reliability is also high because the logical operation results of at least three terminal inputs are used.

In the above-mentioned sections and section E, which describe the present invention in detail, figures of embodiments are used to make the present invention easier to understand, but the present invention is not limited to the embodiments.

F. Embodiment FIG. 1 is a circuit diagram when the crane front is attached. Third
Components similar to those in FIGS. 6 to 6 will be described with the same reference numerals.

Reference numeral 40 denotes a fittest prevention device, which includes four signal input connectors 41 to 44. A terminal 41a of the connector 41 is connected to a common terminal of the hook spiral switch 10, and a terminal 41b is open. The terminal 42a of the connector 42 is connected to the common terminal of the boom suitability switch 12A, and the terminal 42b is connected to the common terminal of the second boom overwinding switch 12B.
Terminal 43a of connector 43 is open, and terminal 43b is grounded. Furthermore, the terminal 44a of the connector 44 is
It is connected to a common terminal of an overload switch 51 that opens when the product of the hanging load and the working radius exceeds a predetermined value. 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 connected to address lines 47A to 47A7 of a read only memory (hereinafter referred to as ROM) 47, respectively. There is. R,
Drivers 48A to 4.8F each consisting of a transistor are connected to data lines 47D1 to 47D6 of 0M47.
Drives 8F.

The swirl prevention device 40 also includes a connector 45 for signal output, the terminal 45a of which is connected to a solenoid 53 for stopping the winding of the main winding rope 4, and the terminals 4 and 5b connected to a solenoid 53 for stopping the winding of the auxiliary winding rope 5. Each is connected to a solenoid 54 for stopping the top. This solenoid 54 is used to stop hoisting of the jib hoisting 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 hoisting rope 5 when the tower front is attached. The terminals 45d are each connected to a solenoid 56 for stopping the hoisting of the hoisting rope 6. This solenoid 5
6 is used to stop hoisting of the tower boom hoisting rope 6 when the tower front is attached. Furthermore, the terminal 45g is connected to a solenoid 57 for stopping the lowering of the hoisting 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
It is connected to a buzzer 58 that sounds when an abnormality occurs.

Figure 2 is a circuit diagram when the tower front is installed.

The terminal 41a of the connector 41 is connected to the common terminal of the hook spiral switch 20, and the terminal 41b is connected to the common terminal of the spiral switch 21 of the tower jib hoisting rope (auxiliary winding rope) 5. Terminals 42a and 42b of the connector 42 are both open, and a terminal 43a of the connector 43 is connected to a common terminal of the spiral switch 22 of the tower hoisting rope 6.

Further, the terminal 44a of the connector 44 is connected to a 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 attached and is opened when the tower front is attached, so that the front can be identified by the signal of the address line 47A. Furthermore, when installing the crane front, the terminal 41b of the jib suitable switch 2] and the tower boom suitable switch 22
and 43a are opened, and terminals 42a and 42b of the boom spiral switch 12A and the second boom overwind switch 12B are opened when the tower front is attached, so the front can be identified by these as well.

In the above configuration, the terminals 42a and 42b are input terminals exclusively for the crane front, the terminal 43a is the input terminal exclusively for the tower front, and the terminal 43b is the identification terminal.

R and 0M47 respectively constitute logical operation means.

Now, in the state shown in Figure 1 where each spiral switch is closed when the crane front is installed, the address signal is r.
olooolooJ, which is normal at this time,
ro OOOOOJ is output to the data lines 47D1 to 47D6. Therefore, no solenoids or buzzers operate, and crane work can be performed by operator operation. When the main winding rope 4 is wound too far and the hook spiral switch 10 is opened, the address signal becomes rlloolooJ, and at this time, the data lines 47DX to 47D8 are connected to the rlooo
Output oooJ. As a result, the driver 48A is driven, the main hoisting hook hoisting stop solenoid 53 is energized, the main hoisting drum 7 is stopped, and the hoisting of the main hoisting rope 4 is stopped. Similarly, when the address signal changes with the operation of each overwind switch, each data line 47D1 to 47D energizes the solenoid corresponding to the operated overwind switch.
A signal is output to 7D6. Similarly, when installing the tower front, the solenoid corresponding to the operated spiral switch is energized and each winch is stopped.

Also, for example, when the wrong cable is connected to the swirl prevention device 40, the terminals 41b and 43a.

Data other than the identification data rlloJ indicating when the crane front is attached is input to terminal 43b, or
2a, 42b, 43b show the tower front installed.
When data other than the identification data 11J is input, it is determined as an error that the drivers 48A to 48F are driven from the data lines 47D to 47D, and the solenoids 53 to 48F are driven.
57 and sounds an alarm buzzer 58.

Table 1 shows identification data for crane front installation, tower front installation, and errors.

Table 1 also shows that if the terminal 41b is short-circuited when installing the crane front due to insulation deterioration, an error will occur, and the data
Since "1" is output to all 1A47D1 to 47D6, in this case as well, all the solenoids 53 to 57 are energized and the alarm buzzer 58 sounds.

In this way, by simply connecting each cable to the input terminals 41a to 44a of the fittest prevention device 40 according to the front, it becomes possible to control the solenoids that match the front according to the logic predetermined in the ROM 47. Therefore,
There is no need for a conventional switch device for selecting the front, and human error is prevented. Furthermore, when installing the crane front and the tower front, the front is identified based on the status of at least three terminals, and each of the three terminals becomes abnormal and the crane front is incorrectly identified as the tower front. The probability of this occurring is extremely low, and reliability is greatly improved.

Furthermore, in one or more embodiments, the ROM 47 is used to configure the logical operation circuit, so the number of parts is reduced compared to the case where a relay or the like is used, which contributes to miniaturization and improved reliability of the device. Furthermore, when the logical conditions become more complex, the RO
The use of M47 is particularly effective.

In the above embodiment, when the front of the crane is attached, if the front identification terminal 43b is opened under the condition that the boom exit switch 12A and the second boom overwind switch 12B are operating, the ROM 47 The address signal indicates one aspect when installing the tower front, 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 configured as follows, it is possible to detect a short-circuit failure in the system of the boom exit switch 12A and a disconnection failure in the system of the second boom overwind switch 12B.

That is, since the boom suitable switch 12A and the second boom overwind switch 12B always operate in that order, the boom exit switch 12A is short-circuited and the second boom overwind switch 1 is short-circuited.
It is impossible for 2B to be open. Therefore, ROM4
7 is identified by the address signal, and when an error is identified, "1" is output from the added address line,
The driver can be notified of the malfunction by displaying a message to that effect or by sounding a separate buzzer with a different tone.

Table 2 shows the above logic and the operation of each solenoid at 0°1.

Table 2 Furthermore, although the case where a tower front is installed in place of the crane front has been described above, the present invention can also be applied to a safety device for a crane in which other front attachments such as a pile driver or an earth drill are installed in addition to the tower front. .

G1 Effects of the Invention According to the present invention, at least three signals are taken into the logic operation means from each input terminal and identification terminal of the abnormality detection means for other fronts such as the crane front and the tower front, and are logically operated. Since the system outputs a signal to avoid the operation in which an abnormality has been detected based on the calculation result, the operator can avoid the operation in which an abnormality has been detected without having to select the front each time when replacing the front. This improves operability and prevents human errors. In addition, since the signals of at least three input terminals are logically operated and an avoidance signal is output, there is no risk of malfunction even if one input terminal suffers insulation deterioration or disconnection, making the device highly reliable. can be provided.

[Brief explanation of drawings]

FIG. 1 and FIG. 2 are circuit diagrams for crane front mounting and tower front mounting, respectively, in this embodiment. Figures 3 and 3. The illustration is Umira. FIG. 3 is a side view of the crane showing the configuration of the tower and the front of the crane. FIGS. 5 and 6 are circuit diagrams showing the concept of a conventional crane front-mounted safety mechanism and a tower front-mounted safety mechanism, respectively. 10: Main hoist hook leaver switch 12A: Boom fitter switch 12B = 2nd boom overwind switch 2o: Tower main hoist hook fitter switch 21: Tower jib leaver switch 22: Tower boom fitter switch 41-44: Connector 41a: Crane and tower common input terminals 42a, 42b
: Crane-dedicated input terminals 41b, 43a : Tower-dedicated input terminals 43b : Identification terminals 47 : ROM (logic operation means) 47A1 to 47A, Near address lines 47D to 47D, : Data lines

Claims (1)

[Scope of Claims] A crane front dedicated input terminal to which a crane front abnormality detection means is connected when a crane front is installed, and is opened when a front other than a crane is installed, and an abnormality detection means for the front when a front other than a crane is installed. and other front-only input terminals that are connected and open when the crane front is installed, and identification terminals that input signals that identify the crane front and other fronts depending on the connection status when the crane front and other fronts are installed. A predetermined logical operation is executed by inputting the signals of each of these terminals, and based on the result of the logical operation, an avoidance signal is generated to avoid the abnormal operation detected by each of the abnormality detection means at the crane front and other front. A safety device for a crane, characterized in that it is equipped with logical operation means for outputting.