JPS5856948A - Anti-overload safety device for crane - Google Patents

Abstract

PURPOSE:To heighten the efficiency and safety of crane work, by automatically setting a hang-up limit value for a boom depending on the direction of turning of the boom, the spread of stabilizing legs and the presence or absence of cargo on a cargo rest to give warning if the hung load exceeds the limit value. CONSTITUTION:A crane 1 is equipped with an anti-overload safety device 15 comprising a boom turning direction detector 16 consisting of a front and a side position detecting units 21, 22, a stabilizing leg spread detector 17 consisting of a right and left stabilizing leg detecting units 29, 28, a boom load detector 18 consisting of a detecting unit 41 and a warning unit 42 and a selective switch 19. When a boom 11 is located at the left side of a ship and a stabilizing leg 7 is protruded sidewards and predetermined load is on a cargo rest 4, these facts are found out by the detectors 16, 17 and the switch 19 is shifted depending on the load and set at the maximum pressure for the detecting unit 41 of the load detector 18. When the boom 11 has exceeded the set pressure, the warning unit 42 gives warning.

Description

[Detailed Description of the Invention] The present invention provides a system for a crane vehicle with a loading platform to issue an alarm when a preset load condition is exceeded, depending on the working conditions such as the rotation direction of the boom, whether or not the act trigger is extended, and the load. This relates to overload safety devices for cranes.

Conventionally, an overload alarm device has been used in a crane vehicle that detects the full pressure of the zoom luffing cylinder and sounds an alarm buzzer when the rated limit moment is reached due to the suspended load. The stability and rated load vary greatly depending on the presence or absence of cargo on the loading platform, the presence or absence of the stability 1lIII (Act Trigger) overhang, and the 9 directions in which the crane is hung, i.e., backwards or laterally relative to the vehicle body.
When loading cargo onto the carrier and extending the stabilizer to extend the boom to the side or rear, the stability is good and the maximum rated load can be obtained. The distance from the center of crane rotation to the front wheel is the fulcrum of the fall. is short, and there is a risk of an accident such as bending the chassis frame connecting the driver's seat and the cargo bed due to overload.Therefore, in this case, it is necessary to lower the rated load.

In addition, as a means of determining pre-rating T■I, f according to the working condition, the boom angle, degree of extension, etc. are measured, and the limit value is set automatically, and if the rated value is exceeded, an alarm buzzer is issued. An overload prevention device, commonly called a moment limiter, has been developed, but it is too expensive and difficult to apply to loading platform I/J crane vehicles.

The present invention has been made in view of this point, and detects the rotation direction of the boom and the presence or absence of the stabilizer extension, and selects and switches the presence or absence of cargo on the loading platform, thereby adjusting the zoom lifting limit. Automatically set, when the suspended load exceeds the limit value,
The present invention provides an overload safety device for cranes that issues an alarm.

Hereinafter, all embodiments of the configuration of the water source 1 will be described based on the drawings.

〔Example/〕

1 to 7 show an embodiment. As shown in FIG. 7, 1 is a crane device attached to a crane truck 2 with a loading platform, and includes a driver's seat 3 at the front and a loading platform 4 at the rear. is established between. This crane device 1 includes a support frame 6 placed on a chassis frame 5, left and right stabilizers 7 and 8 provided on both sides of the support frame 60, a swivel device 9 provided on the top of the support frame 6, and The main components are a swing post 10 attached to the swing device and a telescopic game 11, and an undulation cylinder 12 is arranged between the swing post 10 and the boom 11.

Reference numeral 15 denotes an overload safety device that detects an overload during crane work by the crane device 1 and issues an alarm when the limit load value according to the working conditions of the crane is exceeded, and detects the turning direction of the boom 11. A zoom turning direction detection means 16 for detecting the rotation direction, a stability+1111 overhang detection means 17 for detecting whether the left and right stabilizers 7 and 8 are overhang, a boom load detection device 1.18, and a number selectable according to the load on the loading platform 4. It is mainly composed of a selection switching means 19 (FIG. 7) for selecting J.

The zoom turning direction detecting means 16 includes a front position detecting device f1.21 attached to the turning device 9 and detecting that the boom 11 is in the 011 direction position, and a front position detecting device f1. Side position detection device M 22 that detects the position
1, a detection switch 23 such as a limit switch that is mounted on the 10 side (swivel boss), and a cam plate 24 that is attached to the support frame 6 side.

The detection switch 26 and the cam plate 24 are arranged in such a manner that the switch 26 contacts and closes the cam plate 24 when the boom 11 is in the forward position, that is, within the angle α shown in FIG. The angle α is the dangerous forward suspension range and therefore the area where the rated load needs to be reduced, for example /♂0° forward of the stable 111117.8, or an angle narrower than that. That is.

A lateral position detection device 22, a detection switch 25 including a limit switch etc. that is attached to an appropriate position on the support frame, and a cam plate 26 that is attached to the swing post 10 side! l
When the game 11 is in either the left or right direction, for example in FIG. 2, the boom 11 is positioned within the left angle β,
The switch 25 is arranged so as to come into contact with the cam plate 26. However, the angle β is stable from the rear center of the vehicle body.
It is an angle of approximately 0 degree at 1 which leads to 7.

Therefore, when both the detection switch 23 of the 10-directional position detection device 21 and the detection switch 25 of the lateral position detection device 22 are in the OFF state, the game 11 detects that it is located in the right direction. .

The ballast overhang detection means 17, the left and right stabilizers 111 (
The device is designed to detect whether or not the outrigger is overhanging, and the port ballast detection device 28 and starboard ballast detection device 29
Each of them has a protruding cam 35, 36 that can be taken out of the inner cylinder 32, 33 that can take up the stable base body 30, 61.
Detection switches 37 and 38 such as limit switches are attached to the end of the outer cylinder 34, and each switch is made by, for example, drilling a lever insertion hole 39 in the outer cylinder and facing the lever of the switch. The cam 65 (or 66) is provided oppositely to the protruding cam 65 (or 66) so that when the stabilizer is extended, the respective switches 37 and 38 are closed.

In the map, the finger rotation of the Ail''i game 11 is shown, and IS is the tifi direction of the vehicle.

The zoom load detection device ft 18 is installed directly on the zoom luffing cylinder 12 described in OO or at an appropriate place in the hydraulic circuit for the cylinder. The rated details set according to the presence or absence of hydraulic pressure 114 are converted to 41] pressure, and an alarm is issued when this hydraulic pressure is exceeded.
The main components are a detection member 41 that divides the rated load into a plurality of stages and operates when the hydraulic pressure corresponding to each rated load is reached, and an alarm member 42 such as a buzzer (FIG. 7). This embodiment shows an example in which the pressure switch 46 is set at the rated load meeting stage, and the detection member 41 is connected to the pressure switch 46 that operates at the maximum allowable limit for the game 11, and the game 11 is located in front and the load is a pressure switch 46 that operates at the minimum permissible limit when the ballasts 7, 8 are in the most unfavorable state without being extended, and a pressure switch 44, 45 that operates freely between them; The ratio of the respective operating pressures is, for example, 100 near 5:6θ°2j.

As a means for selectively connecting the operating circuit to each pressure switch, a relay 48 is provided as shown in FIG. 7. This relay 48 has relay contacts 49°50.51 and 5
2, a normally open D contact and a normally closed contact are each pressure switch 43 and 44 as shown.

45 and 46, and the switching relay coil 53
are connected so as to be activated by closing the detection switch 26 of the front position detection device %t'21.

The selection switching means 19 (FIG. 7) is configured to be manually switched depending on the state of the cargo on the loading platform 4'', and is provided, for example, near the operating position of a zoom operating lever (not shown), and Two sets of switches 55 and 56ffi are operated in correspondence with each relay contact of the relay 48, and when the load is empty, each switch is switched to the B contact side, and when a predetermined amount of cargo is reached, all switches are switched to the A contact side.

Next, its operation will be explained based on the operating circuit diagram shown in FIG.

The figure shows the state when the boom 11 is on the port side, the port side stabilizer 7 is extended, the starboard side stabilizer 8 is retracted, and the loading platform 4 has a predetermined load. The detection switch 25 of the detection device 22 and the detection switch 37 of the port ballast detection device 28 are both switched to the A contact side, and the detection switch 68 of the starboard ballast detection 3M29 is released to the normally closed contact side. In contact, the front position detection device 21
The detection switch 23 is released and turned OFF, so each relay contact of the relay 48 is on the normally closed contact side, the selection switching means 19 is switched depending on the load, and each switch 5 is turned off.
5.56 is switched to the contact a side.

In this state, by turning on the main switch 60 fully manual or in conjunction with the hydraulic pump operation switch, one operation port l@62 of the power source 61 is connected to the side position detection device 2.
The first relay contact 49 of the relay 48
Detection part paulownia 41 of poom load detection device 1B with light b contact of
The first pressure switch 43 is kept conductive to the highest set pressure.

Therefore, the game 11 can perform crane lifting work up to the maximum load when the pressure in the luffing cylinder 12 reaches the set pressure, but when the limited pressure is exceeded, the pressure switch 46 closes and the alarm member 42 is activated and an alarm is issued.

2. When the pool 11 moves to the starboard side in the state described in item 2, the detection switch 25 of the side position detection device 22 is switched to the B contact side, and therefore the operation circuit 62 is switched to the contact side. , detection switch 38 of starboard stability gear detection device 29
, the A contact of the second switch 56 of the selection switching means 19 , and the third relay contact 51 of the relay 48
It communicates with the second pressure switch 44 of the detection section 4N'41 through the b contact. As described above, this pressure switch 44 has, for example, a pressure of 100:
If the force is set to 76, then 7.
The alarm member 42 will be activated with a load of 5%.

In this case, when there is no Idt load on the loading platform 4-11, the switches 55 and 56 of the selection switching means 19 are switched to l and lj, respectively, and are shifted to the b contact side, so that the operation circuit 62
It is electrically connected to the third pressure switch 45 of the detection section H'41. The switch 45 is the first pressure switch 4 as described above.
Therefore, the alarm part J': A' 42 (11) is activated with a load of 50% compared to the initial state where the pool 11 is on the port side. becomes.

Next, when the pool 11 is located forward, the detection switch 26 of the front position detection device 21 is in the ON state, so each contact of the relay 48 is switched to the d side, and the detection switch 26 of the side position detection device 22 is turned on. is released and is on the b contact side. In this case, if there is no cargo, the selection switching means 1
Each switch of 9 has returned to the previous state and is on the b contact side, and the switch 111 is stable again.
117, 8 are stored and the respective detection switches 57.3
8 is released and is on the B contact side, the operation circuit 62 is communicated with the G-th pressure valve islet 46, which is set to the lowest pressure of the detection member 41, as is clear from the figure. The set pressure of the switch is set to the first pressure switch 46 as described above.
If θθ゛, 2j, then the alarm will be issued at a load of 15% compared to the most advantageous state in which the first game 11 is on the port side.

〔Example! ]

The above embodiment has shown an example in which a plurality of pressure switches (12), each set to a different limit setting pressure, which are activated by the pressure in the undulation cylinder 12, are used as the poom load detection device. The present embodiment shown in Figs. 2 and 2 uses a Gluton tube, and uses the pressure inside the cylinder to rotate the pointer, so that when the required set pressure is reached, the alarm member is fully activated. Then, a permanent magnet 72 was attached to the back side of the pointer 71 of the Bourdon tube 70, and unit non-contact switches 74 were arranged in parallel on the plate 73 so as to operate each according to the ratio of the rated load, as in the previous example. The non-contact switch rows 75, 76, 77, and 78 of the non-contact switch row are provided, and the alarm member 42 is activated when the pointer 71 overlaps with each non-contact switch. boom rotation direction detection means, stable expansion u'
The detection means, load selection switching means, and wiring procedure are the same as in the previous example. Compared to the 11th example, this method has the advantage of being able to detect the load of the Bourdon tube pressure gauge/combined Niyori boom, requiring less installation space, and being able to be provided at a lower cost.

In the improved reporter embodiment, an example was shown in which the selection switching means for the load condition is divided into two stages: loaded and empty. It may be divided into stages or more,
Moreover, the pressure limit setting values of each pressure switch or non-contact switch row of the pool load detection device may be further classified into two categories beyond the "gu" stage, and other design changes may be made arbitrarily without departing from the scope of the present invention. Of course.

As described above, according to the present invention, the usage conditions of the crane,
In other words, whether or not there is a load on the loading platform, whether or not the stabilizing legs are extended,
With respect to the rated load that is appropriately selected depending on the direction of rotation of the poom, crane work can be carried out effectively and safely within the allowable range according to each condition, and the poom angle used in some conventional cases, Compared to a so-called moment limiter that determines a limit value by comparing and calculating depending on the boom length, etc., it has the advantage that it can be provided at a lower cost.

[Brief explanation of the drawing]

The drawings illustrate embodiments of the present invention, and FIGS. 1 to 7 show embodiments. FIG. 1 is an overall side view of a crane truck with a loading platform, FIG. 2 is a plan view thereof, and FIG. The figure is a front view of the main part along line I-I in Figure 2, Figure 5 is an explanatory diagram of the front position detection device, Figure 5 is an explanatory diagram of the side position detection device,
Figure 1 is an explanation of the stabilizing leg detection device, Figure 7 is a block diagram of the crane overload safety device, Figures 2 and 2 are a second embodiment, and Figure 2 is an explanatory diagram of the main parts. , FIG. 2 is a vertical sectional view of the main part. 1... Crane device, 2... Crane truck with loading platform, 4... Loading platform, 7 Left stabilizing leg, 8...
・ Right stabilizing leg, 9 Swivel device, 10 - Swivel post,
11...Zoom, 15... Overload safety device, 16...
...Zoom turning direction detection means, 17...Safety leg extension detection means, 18...Zoom load detection device, 19
...Selection switching means, 21...Front position detection device, 22...Side position detection device, 26...
Detection switch (forward position detection device, 29... starboard stability leg detection device, 65... port side protruding cam, 6
6... Starboard protruding cam, 67... Port detection switch, 38... Starboard detection (15) detection switch, 41 Detection member, 42... Alarm member, 55.56... switch (for selection),
70... Gluton tube, 75, 76.77.78
... Non-contact switch row patent applicant ShinMaywa Industries Co., Ltd. (16) ＼ To --

Claims (5)

[Claims] (1) In a crane vehicle with a loading platform in which a crane equipped with a stable 1lIf1 and a boom that can be raised and retracted on a swing post is mounted on a traveling vehicle having a loading platform, a zoom direction detection means for detecting the turning direction of the zoom. and a stable overhang detection means for detecting all the overhang working conditions of the stable legs,
It is equipped with a selection switching means that changes the selection according to the loading rate of cargo on the loading platform, and a zoom load detection device that detects the load on the zoom, and detects overload conditions and issues an alarm according to the conditions of crane work. An overload safety device for a crane, which is characterized by the following: (2) The crane according to claim 1, wherein the zoom direction detection means comprises a lateral position detection device that detects the left and right side boom positions including the rear position, and a front position detection device that detects the forward game position. overload safety device. (3) The cargo loading rate selection switching means is configured at least when the vehicle is empty;
The overload safety device for a crane according to claim 1, further comprising a changeover switch for selecting between loading and loading. (4) The overload safety device for a crane according to claim 1, wherein the detection member of the boom load detection device is a group of pressure switches having different set pressures, which are proportional to the rated load of the crane. (5) Crane overload safety according to claim 1, wherein the detection member of the boom load detection device is a group of non-contact switches that are proportional to the rated load of the crane and operate at different set pressures. Place.