JP2516865Y2 - Counterweight mounting state detection device for mobile cranes - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial field of use] The present invention relates to a detection device for detecting the mounting state of a plurality of types of counterweights that are attached to and detached from the rear end of a mobile crane.

[Conventional technology]

As shown in FIG. 6, the mobile crane has a structure in which a swivel base B is mounted on a carriage A, and a retractable boom C is mounted from the swivel base B so that the boom C can be lifted up and down. In order to maintain stability, it is common to equip the rear end of the swivel base B with a plurality of types of so-called counterweights W. That is, as shown in FIG. 7, a suspension jack D of a counterweight composed of a hydraulic cylinder is provided at the rear end of the swivel base B, and the suspension jack D, that is, the rod d ₂ of the hydraulic cylinder d _{1 is used for} the counterweight W, That is, the weights W ₁ , W ₂ , W ₃ , W ₄ divided into _four
To suspend. Then, the actual value of the overturning moment applied to the crane part is compared with the safety limit value, and an alarm is issued or the movement of the crane part is stopped according to the comparison result. A safety limit signal corresponding to each safety limit value according to the equipment state of the counterweight on the rear end of the swivel is automatically taken out.

In this case, in the conventional mobile crane, the detection switches Sw ₁ , Sw ₂ , Sw ₃ , Sw ₄ are attached to the respective weights mounted via the actuators not shown, and the weights W divided into a plurality of blocks are attached. ₁ , W ₂ , W ₃ and W ₄ are appropriately combined according to the crane's hoisting load, and the hoisting jack D is used for hoisting equipment.

[Problems to be solved by the device]

As described above, since the conventional mobile crane is equipped with the detection switches Sw ₁ , Sw ₂ , Sw ₃ , and Sw ₄ that detect the detached state of each weight for a plurality of types of weights to be detached, As the number increases, the mounting of the detection switch becomes complicated, and the detection switch may be damaged when the weight is attached and detached.

The present invention solves the above problems of the prior art,
Even if the counterweight W divided into a plurality of blocks is suspended, only one detector is required and the installation is simple, and the detector can be prevented from being damaged when the counterweight is attached or detached. It is an object of the present invention to provide a counterweight wearing state detecting device in.

[Means for solving the problem]

As a concrete means for achieving the above object, the present invention provides a counterweight comprising a weight attaching / detaching means at the rear end portion of a swivel base, and the weight attaching / detaching means appropriately combining weights divided into a plurality of blocks. When hanging, equip with a counterweight mounting state detector that detects the load acting on the weight attaching / detaching means or the mounting bracket of the weight attaching / detaching means, and based on the detection value of the counterweight attached state detector. It is an object of the present invention to propose a counterweight mounting state detection device for a mobile crane, characterized by comprising a discrimination means for discriminating the counterweight of the state.

[Action]

The load acting on the weight attaching / detaching means or the mounting bracket of the weight attaching / detaching means depending on the weight of the counterweight is detected by the counterweight attached state detector, and the attached state counterweight is discriminated by the discriminating means based on the detected value.

〔Example〕

Embodiments of the present invention will be described below in detail with reference to the drawings.

1 and 2 are a side view and a plan view showing a weight attaching / detaching means F in which a counterweight attaching / detaching device is attached to a rear end portion of a swivel base B. In this example, the weight attaching / detaching means F is a hanging jack D made up of a hydraulic cylinder.
And is installed on both sides of the rear part of the swivel base B (one of which is omitted in FIG. 2). That is, the bracket 3 for supporting the hydraulic cylinder d ₁ of the lifting jack D is provided above and below the rotary shaft 2 pivotally supported by the frame 1 of the swivel B.
3 is attached, and the hydraulic cylinder is attached to the brackets 3 and 3.
Supports d ₁ vertically. Therefore, the suspension jack D is swiveled in the direction of the rear end of the swivel base B about the rotary shaft 2 as a support shaft, and its movement can be adjusted in the front-rear direction so that an unbalanced load does not act on the suspension jack D. There is.

The means for attaching and detaching the hanging jack D and the counterweight W is the rod of the hydraulic cylinder d ₁ that constitutes the hanging jack D.
A locking flange 5 is provided at the lower end of d ₂ and the locking flange 5 is engaged with and disengaged from a locking groove 6 formed along the upper surface of the weight W ₁ or W ₂ .

_On the upper end side of the rod d ₂ of the hydraulic cylinder d _{1, when} the weight W ₁ or W ₂ is lifted to a predetermined height position, that is, the lower surface position of the swivel base B in FIG. 1, the rod d ₂ is hydraulically moved. An insertion hole 8 for a lock pin 7 for locking on the cylinder d ₁ side is formed. Reference numeral 9 denotes a bracket for receiving the lock pin 7, which is the hydraulic cylinder.
It is mounted on the upper flange of d ₁ . Further, the bracket 9 is provided with a U-shaped receiving groove 9a for fitting and receiving the lock pin 7 inserted into the rod d ₂ . When the lock pin 7 is pulled out from the insertion hole 8, the lock of the rod d ₂ is released. Reference numeral 10 is a rotation stopper attached to the upper end of the rod d ₂ .

FIG. 3 shows an example in which the weights W ₁ , W ₂ , W ₃ , W ₄ , and W ₅ divided into five blocks are suspended in the suspension jack D. The weights W ₁ and W ₂ are combined and joined by inserting a plurality of guide shafts 12 standing on the upper surface of the weight W ₂ into guide holes 13 formed on the lower surface of the weight W ₁ . Also, in the case of weight W ₂ ~ W ₅ coupling,
Similarly, first, a plurality of guide shafts 14 are erected in advance on the upper surface of the weight W ₅ , while the weights W ₃ and W ₄ are provided with through holes 15 through which the guide shafts 14 can pass. Insert the guide shaft 14 into the hole 15,
Stack weights W ₃ and W ₄ on top of weight W ₅ . Then, the bracket 17 for the pre-mounting and connected to the lower surface of the weight W _2, the upper end portion of the guide shaft 14 provided upright on the weight W _5, and configured to be coupled to the suspension system using a connecting bolt 16 ing.

Now, the weight W ₁ to _W-5, which was incorporated suspended is divided into a plurality of blocks, the past, were those provided with the respective detection switch as mentioned above, in the present invention, instead of the detection switch As shown in FIG. 1, the hydraulic cylinder d ₁ is equipped with a counterweight mounting state detector K for detecting the weight of the counterweight W mounted on the suspension jack D.

The internal pressure detecting pressure gauge 20 attached to the counter weight holding side of the hydraulic cylinder d ₁ is one embodiment of the counter weight mounting state detector K. The split weights W ₁ , W ₂ , W ₃ , W ₄ , and W ₅ are preliminarily designed so that they can be suspended and used by the following combinations.

(1) W ₁ (2) W ₁ ＋ W ₂ (3) W ₂ ＋ W ₅ (4) W ₂ ＋ W ₄ ＋ W ₅ (5) W ₂ ＋ W ₃ ＋ W ₄ ＋ W ₅ (6) W ₁ ＋ W ₂ ＋ W ₃ ＋ W ₄ + W ₅ Of course, the combination of these weights W _{1 to} W ₅ to be suspended on the suspension jack D is selected according to the suspension load of the crane, as already described.

Then, for example, as the counter weight W, the weight
In the case of using only W ₁ alone (1), the pressure gauge 20 for detecting the internal pressure of the hydraulic cylinder shows a gauge pressure P ₁ .
Similarly, when the combination of weights W ₁ and W ₂ is used (2), gauge pressure P ₂ , and in the case of (3),
In the case of gauge pressure P ₃ , (4), it indicates gauge pressure P ₄ , in the case of (5), gauge pressure P ₅ , and in the case of (6), gauge pressure P ₆ . In other words, when the internal pressure detecting pressure gauge 20 indicates a gauge pressure of P ₁ , the counterweight W suspended in the suspension jack D is only the weight W ₁ alone, and the gauge pressure is P ₂ . In some cases, the weight is W ₁ + W ₂ , and when the gauge pressure indicates P ₆ , the weight W ₁ + W ₂ + W ₃ + W ₄ + W ₅ can be specified in correspondence with the following combinations.

Strain gauge 21 attached to the rod d ₂ of the hydraulic cylinder d ₁ of FIG. 1 is a diagram showing the another embodiment of the counterweight mounted state detector K. Strain gauge 21
Are weights W _{1 to} W ₅ to be suspended on the suspension jack D.
Depending on the selection of the combination, the same as the case of the internal pressure detecting pressure gauge 20, different measurement values are shown, and the combination of respective weights can be specified corresponding to the measurement value.

Next, the measured value E applied to the crane part, that is, the fifth value
The actual value E of the tipping moment calculated from the length d of the boom C of the crane section, the elevation angles θ ₁ and θ _{2 of} the boom C, and the loads L ₁ and L ₂ shown in the figure is the safety limit shown in FIG. Monitoring device
The safety limit value is compared at 30 and an alarm is issued or the movement of the crane section is stopped depending on the comparison result. The memory 32 of the safety limit monitoring device 30 stores a plurality of safety limit values in advance depending on the counterweight mounting state. Then, the detection value of the counter weight mounting state detector K is used as a selection signal for selecting an appropriate safety limit value from the plurality of safety limit values. In other words, the detection value of the counter weight mounting state detector K is used by the discriminating means G of the safety limit monitoring device 30 to discriminate the counter weight in the mounting state, and the discrimination result signal S is input to the computing unit 31. The arithmetic unit 31 compares an appropriate safety limit value retrieved from the storage device 32 based on the input signal S with an actual measurement value E applied to the crane unit to determine whether or not the crane is in a safe state. . Then, based on the result of this determination, the boom extension regulation, the boom fall regulation and the winch hoisting regulation as the crane operation regulation means 33 are controlled and instructed. The determining means G uses the counter weight mounting state storage device 52 that stores the counter weight mounting state and the detection value from the counter weight mounting state detector K based on the detection values from the counter weight mounting state detector K. Based on the above, there is provided a computing unit 51 for discriminating the mounted state of the counterweight, and lamps 41 to 46 corresponding to the mounted counterweight so that the computing unit 51 can identify the mounted counterweight. Then, based on the detection value from the counter weight mounting state detector K, each of the lamps 41, 42, 43, 44, 45 of the counter weight mounting state display lamps 40 indicating which combination weight is suspended in the suspension jack. The designated lamps at 46 and 46 are turned on.

In the above embodiment, the crane has the safety limit monitoring device 30, the safety limit monitoring device 30 is provided with the discriminating means G, and the detection value of the counterweight mounting state detector K is appropriately selected from a plurality of safety limit values. Although the case of using as a selection signal for selecting an appropriate safety limit value has been described, a crane that does not have the safety limit monitoring device 30 may include only the determination means G.

As described above, the counterweight mounting state detecting device in the mobile crane according to the present invention is equipped with the counterweight mounting state detector on the hydraulic cylinder as the weight attaching / detaching means, and the mounting state of the counterweight is detected based on the detected value. It is provided with a discriminating means for discriminating the counterweight. In this case, if the counterweight mounting state detector is designed to detect the internal pressure of the hydraulic cylinder d ₁ , the insertion hole 8 formed on the upper end side of the rod d ₂ in FIG. Before locking the rod d ₂ to the hydraulic cylinder d ₁ side by inserting the lock pin 7 into it, it is necessary to measure and detect the gauge pressure and hold the detection result before locking when locking. . Further, as the strain gauge for detecting the strain, in addition to utilizing the stress of the rod of the hydraulic cylinder described above, the stress of the bracket to which the hydraulic cylinder is attached may be detected.

In addition, although the mobile jack in which the lifting jacks D are mounted on both sides of the rear portion of the swivel base B has been described in the embodiment, the present invention is not limited to this example, and the point is that the rear end portion of the swivel base is important. The present invention is applicable to any mobile crane in which a weight attaching / detaching means such as a suspension jack made of a hydraulic cylinder is provided, and a counterweight formed by combining weights divided into a plurality of blocks by the weight attaching / detaching means is suspended.

[Effect of device]

According to the present invention, a counterweight for suspending a weight divided into a plurality of blocks on a weight attaching / detaching means provided at a rear end portion of a swivel base and detecting a load acting on the weight attaching / detaching means or a mounting bracket of the weight attaching / detaching means. Since the mounting state detector is mounted, and the counter weight is discriminated based on the detection value of the counter weight mounting state detector, a discrimination means is provided. It is not necessary to provide a detection switch for detecting the attachment / detachment state of the weight, and only one detector is required, and the attachment is simple. In addition, it is possible to prevent an accident that is likely to occur in the related art that the detector is damaged when the counterweight is attached and detached.

As described above, the practical effect of the present invention is great.

[Brief description of drawings]

1 to 5 are embodiments of the present invention. FIG. 1 is a side view showing a state in which a weight is suspended in a suspension jack, FIG. 2 is a plan view of the same, and FIG. FIG. 4 is a side sectional view showing a state in which a plurality of divided weights are suspended, FIG. 4 is a circuit explanatory diagram showing a connection state between a counter weight mounting state detector and a safety limit monitoring device, and FIG. 5 is a mobile crane. It is a side view. FIG. 6 is a side view of a conventionally known mobile crane equipped with a counterweight, FIG.
The figure is a side view showing a state in which the split weight is suspended in the suspension jack at the rear end of the mobile crane. A ... carriage, B ... swivel base C ... boom, D ... hanging jack d ₁ ... hydraulic cylinder, d ₂ ... rod E ... Found F ... wait desorption unit G ... judging means K ... counterweight mounting state detection applied to the crane unit Equipment P ₁ , P ₂ , P ₃ , P ₄ , P ₅ … Gauge pressure W… Counterweight W ₁ , W ₂ , W ₃ , W ₄ , W ₅ … Weight d… Boom length, θ ₁ , θ ₂ … Depression angle L ₁ , L ₂ … Load 1… Frame, 2… Rotating shaft 3… Bracket, 5… Locking flange 6… Locking groove, 7… Lock pin 8… Insert hole, 9… Bracket 9a… Receiving groove , 10 ... Rotation stop 12, 14 ... Guide shaft 13 ... Guide hole, 15 ... Through hole 16 ... Connecting bolt, 17 ... Bun-acket 20 ... Pressure gauge for detecting internal pressure 21 ... Strain gauge 30 ... Safety limit monitoring device 31 ... Computing unit, 32 ... Memory device

Continuation of the front page (51) Int.Cl. ⁶ Identification code Office reference number FI Technical display area E02F 9/18 E02F 9/18

Claims (3)

(57) [Scope of utility model registration request] 1. A weight attaching / detaching means is provided at a rear end portion of a swivel base, and the weight attaching / detaching means or this weight attaching / detaching is used for suspending a counterweight formed by appropriately combining weights divided into a plurality of blocks by the weight attaching / detaching means. Equipped with a counterweight mounting state detector that detects the load acting on the mounting bracket of the means,
A counterweight mounting state detecting device for a mobile crane, characterized by further comprising a discriminating means for discriminating the counterweight in the mounted state based on the detection value of the counterweight mounted state detector. 2. The weight attaching / detaching means is composed of a suspension jack composed of a hydraulic cylinder, and the counter weight mounting state detector is an internal pressure detecting pressure gauge attached to the counter weight holding side of the hydraulic cylinder or the hydraulic cylinder. The counterweight mounting state detection device in a mobile crane according to claim 1, wherein the strain gauge is a strain gauge attached to the rod. 3. A mobile crane having a safety limit monitoring device for comparing an actual measurement value applied to a crane part with a safety limit value and issuing an alarm or stopping the movement of the crane part according to the comparison result. Uses the detection value of the counterweight mounting state detector as a selection signal for selecting an appropriate safety limit value from the plurality of safety limit values,
The counterweight mounting state detecting device for a mobile crane according to claim 1 or 2, wherein the safety limit monitoring device is provided with the determining means.