JP2019156579A - Loading-type truck crane - Google Patents

Abstract

To provide a loading-type truck crane capable of maximizing the capacity of a crane device while ensuring the safety of the work without limiting the work capacity in the front area.SOLUTION: A loading-type truck crane 10 includes a front outrigger device 33 and a rear outrigger device 37 that are respectively provided at the front and rear of a vehicle body, a rear jack 39 that is provided at each of the left and right outer ends of the rear outrigger device 37, and a control device 12 for receiving a status signal of the rear jack 39. The control device 12 regulates the operation of a crane device 26 based on the state signal from the rear jack 39 when a boom 32 constituting the crane device 26 is located in the front region. The loading-type truck crane 10 does not limit the work capacity in the front area. For this reason, the capability of the crane device can be maximized, while the safety of work is ensured.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a load-type truck crane. More specifically, the present invention relates to a load-type truck crane in which outriggers are provided on the front, rear, left and right sides of the vehicle body. In the present specification, the descriptions of front, rear, left and right are front, rear, left and right with reference to the user in a state where the user of the loadable truck crane is in the cab of the vehicle body.

  A load-type truck crane is a vehicle in which a crane device is mounted on a truck having a loading platform. The crane apparatus is mounted between the cab and the loading platform. The crane device is operated by extracting power from a prime mover for traveling. In the load-type truck crane, the boom of the crane device is turned around the base portion of the crane device and the boom is expanded and contracted during the crane operation. This operation lifts the cargo and transports the cargo.

  In a load-type truck crane, an outrigger device is provided on the vehicle body in order to ensure the stability of the vehicle body during crane work. In some cases, for example, one outrigger device is provided in the vicinity of the crane device and the other is provided in the rear of the vehicle body. At this time, a total of four hydraulic jacks are provided, one on each of the front, rear, left and right sides of the vehicle body. When carrying out the crane work, the user of the load-type truck crane works with the outriggers protruding from the vehicle body.

  The rated load of a load-type truck crane is based on the capacity at the turning position (stability when empty) with the lowest stability in the side area and the strength of the crane structure, with no load on the loading platform. Calculated from the determined capacity (crane strength performance). The graph in FIG. 3 of Patent Document 1 is an example of the rated load thus calculated. In Patent Document 1, an alarm is issued or the operation is stopped depending on the ratio of the lifting load to the rated load. Are disclosed.

JP-A-9-86873

  However, since the rated load in the graph of FIG. 3 of Patent Document 1 is calculated in advance in consideration of the ability at the turning position having the lowest stability in the lateral region, there is a margin on the safe side. The bill has become very large. Further, in the front region of the load-type truck crane, the rated load of the crane device is 25% in consideration of the structure. Then, there is a problem that the load rating of the load-type truck crane is excessively limited particularly in the front region.

  The load-type truck crane has a structure in which a loading platform is installed on the rear side of the crane device. The rated load is based on the assumption that no loading is placed on the loading platform. Then, when there is a load on the loading platform, there is a load behind the outrigger device on the front side, so the stability of the load-type truck crane is increased and the restriction in the front area is relaxed so that it is close to the crane strength performance It should be. However, since the calculation method of the rated load in the front region is as described above, there is a problem that the restriction on the front region is excessive in this respect as well.

  In view of the above circumstances, the present invention provides a load-type truck crane capable of drawing out the capacity of a crane device to the maximum while ensuring the safety of work without restricting the work capacity in the forward region. The purpose is to do.

A loading type truck crane according to a first aspect of the present invention is a loading type truck crane provided with a crane device between a driver's cab and a loading platform, and the loading type truck crane includes front parts respectively provided in front of and behind the vehicle body. Outrigger device and rear outrigger device, rear jacks respectively provided at left and right outer ends of the rear outrigger device, a control device for receiving a ground reaction force signal of the rear jack, and an alarm device connected to the control device And the control device has a function of restricting at least the operation of the crane device based on the ground reaction force signal when a boom constituting the crane device is located in a front region, or One of the functions for operating the alarm is activated.
In the loaded truck crane of the second invention, in the first invention, the ground reaction force signal from the rear jack is a signal indicating a reaction force from a ground reaction force measuring device provided in the rear jack. Features.
The loading type truck crane of the third invention is the function of the first invention or the second invention, wherein the control device regulates at least the operation of the crane device when the value of the ground reaction force signal falls below a threshold value, Or any one of the functions for operating the alarm, and the threshold value is at least the working radius of the boom, the turning angle of the boom, the suspended load of the crane device, and between the rear outrigger device and the front outrigger device. It is calculated using any one of the distances.
In the loaded truck crane of the fourth invention, in the third invention, when the threshold value is Ft, Ft is (N-1) · R · (cos θ) · Wt / H (N: safety factor, R: The working radius of the boom, θ: a turning angle from the front front of the boom, Wt: a suspended load of the crane device, and H: a distance between the rear outrigger device and the front outrigger device). It is characterized by.

According to the first aspect of the present invention, the control device regulates the operation of the crane device based on the ground reaction force signal from the rear jack, so that the work capacity in the front region is limited with a large margin. It is not carried out with a load, and the work capacity in the front area is not limited too much. For this reason, while ensuring the safety of work, the capacity of the crane device can be maximized, and the work capacity of the load-type truck crane is improved.
According to the second invention, since the ground reaction force signal from the rear jack is a signal indicating the reaction force from the ground reaction force measuring device, the state of the ground reaction force can be accurately grasped. Can be improved.
According to the third invention, the threshold value for regulating the operation of the crane device is at least the working radius of the boom, the turning angle of the boom, the suspended load of the crane device, and between the rear outrigger device and the front outrigger device. Since the operation of the crane apparatus is limited by a threshold value that matches the actual operation of the crane apparatus, the work capacity of the load-type truck crane is further improved.
According to the fourth aspect, since the threshold is calculated in consideration of the safety factor, the safety of work can be further improved.

It is a side view of the loading type truck crane concerning a 1st embodiment of the present invention. FIG. 2 is a hydraulic circuit diagram of the loading truck crane of FIG. 1. FIG. 2 is a control circuit diagram of the loading truck crane of FIG. 1. It is explanatory drawing of the work area | region of the loading-type truck crane of FIG. It is an operation | movement flowchart of the loading-type truck crane of FIG.

  Next, an embodiment of the present invention will be described with reference to the drawings. However, the embodiment described below exemplifies a loadable truck crane for embodying the technical idea of the present invention, and the present invention does not specify the loadable truck crane as follows. Note that the size, positional relationship, and the like of the members shown in each drawing may be exaggerated for clarity of explanation.

<First Embodiment>
(Loading truck crane 10)
FIG. 1 shows a side view of a loadable truck crane 10 according to a first embodiment of the present invention. As shown in FIG. 1, the load-type truck crane 10 has a crane device 26 mounted on a vehicle frame 29 between a cab 27 and a loading platform 28 of a general-purpose truck 25.

  The crane device 26 includes a base 30 fixed on a vehicle frame 29, a post 31 provided so as to be able to turn with respect to the base 30, a boom 32 provided on an upper end portion of the post 31, and a base 30. And a rear outrigger device 37 that is provided behind the vehicle frame 29 and extends leftward and rightward from there.

  Hydraulic front jacks 38 are respectively provided at the left and right ends of the front outrigger device 33 (see FIG. 4). Similarly, hydraulic rear jacks 39 are respectively provided at the left and right ends of the rear outrigger device 37 (see FIG. 4).

  The post 31 has a built-in winch. A wire rope is led from the winch to the tip of the boom 32 and hung around the hook 34 via a pulley at the tip of the boom 32, so that the hook 34 is suspended from the tip of the boom 32.

  The crane apparatus 26 is hydraulically driven by a hydraulic circuit. Lever groups 35 for operating this hydraulic circuit are provided on both the left and right sides of the base 30. A control device 12 that electrically controls the hydraulic circuit and controls the work vehicle is provided in the base 30.

(Hydraulic circuit 40)
FIG. 2 shows a hydraulic circuit diagram of the load-type truck crane according to the present embodiment. As shown in FIG. 2, the hydraulic circuit 40 of the crane apparatus 26 mainly includes a hydraulic valve unit 41, a hydraulic pump 43 that supplies hydraulic oil in the tank 42 to the hydraulic valve unit 41, a hydraulic pump 43, and a hydraulic valve. The main oil passage 44 that connects the unit 41, the return oil passage 45 that connects the hydraulic valve unit 41 and the tank 42, the hoisting operation of the crane device 26, the telescopic operation of the boom 32, the turning operation of the boom 32, and the like. For this purpose, it includes a plurality of crane device actuators 46, two front jacks 38, and two rear jacks 39. The crane device actuator 46, the front jack 38 and the rear jack 39 are connected to the hydraulic valve unit 41.

  The hydraulic pump 43 is connected to the engine 36 of the general-purpose truck 25 via a PTO (power take-off) device, and is driven by the engine 36.

  The hydraulic valve unit 41 includes a boom turning control valve 47a, a boom expansion / contraction control valve 47b, a boom raising / lowering control valve 47c, a right front jack control valve 48a, a left front jack control valve 48b, a right rear jack control valve 49a, and a left side. A rear jack control valve 49b is provided. The boom turning control valve 47a is connected to the boom turning actuator 46a, the boom extension / contraction control valve 47b is connected to the boom extension / contraction actuator 46b, and the boom raising / lowering control valve 47c is connected to the boom raising / lowering actuator 46c. The right front jack control valve 48a is located on the front jack 38 located on the right side, the left front jack control valve 48b is located on the front jack 38 located on the left side, and the right rear jack control valve 49a is located on the rear jack 39 located on the right side. The left rear jack control valve 49b is connected to a rear jack 39 located on the left side.

  Each of these switching control valves is provided with a lever, and the direction and flow rate of hydraulic oil supplied from the hydraulic pump 43 can be switched by manually operating the lever. The lever attached to the control valve is provided as a lever group 35 on both the left and right sides of the base 30 (see FIG. 1).

  The control device 12 is also connected to an ECU (engine control unit) of the engine 36 and is configured to control at least the rotational speed of the engine 36. The control device 12 can control the rotational speed of the hydraulic pump 43 by controlling the rotational speed of the engine 36 and can adjust the discharge amount of the hydraulic pump 43.

(Control circuit)
FIG. 3 shows a control circuit diagram of the loadable truck crane 10 according to the present embodiment. On the input side of the control device 12, two ground reaction force measuring devices 13, a boom length detector 15, a boom turning angle detector 16, a boom undulation angle detector 17, and a undulation support force detector 18, Are electrically connected. Further, on the output side of the control device 12, an alarm device 14, a boom turning control valve 47a, a boom expansion / contraction control valve 47b, a boom raising / lowering control valve 47c, a right front jack control valve 48a, a left front jack control valve 48b, The right rear jack control valve 49a and the left rear jack control valve 49b are electrically connected. It is possible to input a predetermined value as a distance between the rear outrigger device 37 and the front outrigger device 33 to the control device 12 according to the type of the loadable truck crane 10.

  The boom length detector 15 is for detecting the length of the boom 32, and is, for example, a cord feed length detector. The cord feeding length detector detects the feeding length of the length measuring cord by detecting the rotational displacement amount of the cord winder.

  The boom turning angle detector 16 is for detecting the turning angle of the boom 32, and is arranged on the base side of the post 31. For example, the boom turning angle detector 16 is a potentiometer. A rotary encoder may be used in place of the potentiometer.

  The boom hoisting angle detector 17 is for detecting the hoisting angle of the boom 32, and is disposed on the base side of the boom 32. For example, the boom undulation angle detector 17 is a potentiometer. A rotary encoder may be used in place of the potentiometer.

  The ground reaction force measuring device 13 is provided on each of the left and right rear jacks 39. In the present embodiment, the ground reaction force measuring device 13 is a measuring device that can measure the reaction force applied to the rear jack 39, and includes, for example, a strain gauge provided in the rear jack 39, The rear jack 39 may be configured to include a pressure gauge of a hydraulic cylinder. The reaction force measured by the ground reaction force measuring device 13 is output to the control device 12.

  Since the ground reaction force signal from the rear jack 39 is a signal indicating the reaction force from the ground reaction force measuring device 13, the state of the ground reaction force can be accurately grasped, so that the safety of work can be improved. it can.

  The alarm device 14 is for making the user of the load-type truck crane 10 aware of the state when a predetermined state is reached, for example, when the suspension load exceeds the rated load. . In the present embodiment, the alarm device 14 is provided outside the cab 27.

  The undulating support force detector 18 is provided to detect a load hung on the hook 34. In the present embodiment, the hoisting and supporting force detector 18 is a differential pressure gauge provided in a boom hoisting cylinder. The differential pressure detected by the undulating support force detector 18 is output to the control device 12.

(Work area)
FIG. 4 is an explanatory diagram of a work area of the loadable truck crane 10 according to the present embodiment. FIG. 4 is a plan view of the loadable truck crane 10. In the present embodiment, the loadable truck crane 10 is provided with two outrigger devices, a front outrigger device 33 and a rear outrigger device 37. The user of the load-type truck crane 10 performs the work of raising and lowering the load with these two outrigger devices fully extended outward.

  The load-type truck crane 10 is structurally different in the weight of the load that can be safely loaded and unloaded depending on the angle in the horizontal plane of the boom 32 constituting the crane device 26, that is, the turning angle. In general, the load rating of the load-type truck crane 10 is set for each of the following three regions: a rear region, a side region, and a front region. The rear region is a region between the line segments connecting the rotation center of the boom 32 and the left and right rear jacks 39 in the plan view (the smaller angle formed by the two line segments). The side area is an area between the line segment connecting the rotation center of the boom 32 and the right rear jack 39 and the line segment connecting the rotation center of the boom 32 and the right front jack 38 (two lines). Between the rotation center of the boom 32 and the left rear jack 39, and the line segment connecting the rotation center of the boom 32 and the left front jack 38. This is a region (the side having a smaller angle formed by two line segments). The front area is an area between the line segment connecting the rotation center of the boom 32 and the left and right front jacks 38 (the side having a smaller angle formed by two line segments). In the present embodiment, the three areas are defined as described above, but the definition of these areas may differ depending on the configuration of the loadable truck crane 10. Moreover, since the boundary of each area | region is judged with the signal from the boom turning angle detector 16, it may differ from the position by the said definition strictly.

(Operation flow)
In FIG. 5, the operation | movement flowchart of the loading-type truck crane 10 which concerns on this embodiment is shown. The control device 12 of the loadable truck crane 10 first acquires information on the turning angle of the boom 32 from the boom turning angle detector 16 in step 01 (hereinafter described as S01).

  In S02, the control device 12 determines whether or not the boom 32 is located in the front area. When it is determined that the control device 12 is not located in the front region, the boom 32 is located in the side region or the rear region, so that the control device 12 performs a normal operation in the side region or the rear region.

  If it is determined in S02 that the control device 12 is located in the front region, the boom 32 is located in the front region, and the control device 12 proceeds to S03.

  In S <b> 03, the control device 12 acquires a ground reaction force signal from the ground reaction force measuring device 13 provided in the rear jack 39. When the control device 12 determines in S04 that the numerical value of the ground reaction force is equal to or less than the threshold value, the control device 12 proceeds to S05.

  In S05, the control device 12 regulates the operation of the crane device 26 in the front region with the boom turning control valve 47a and the like. Specifically, the hoisting operation of the boom 32 is stopped, or the turning operation of the boom 32 is stopped. Moreover, the control apparatus 12 may perform the operation | movement regulation which makes these operation speeds slow. In conjunction with this operation restriction, the control device 12 activates the alarm device 14 to let the user of the loadable truck crane 10 know that the operation restriction has been activated in the front area. Moreover, only the alarm device 14 may be operated.

  When the control device 12 determines in S04 that the numerical value of the ground reaction force is greater than the threshold value, in S05, the control device does not restrict the operation of the crane device 26 in the front region.

(Threshold calculation method)
In S04, the control device 12 determines whether the value of the ground reaction force signal is equal to or less than the threshold value. The threshold value at this time may be a fixed value, but is preferably determined in consideration of the state of the crane device 26. For example, the working radius R of the boom 32, the turning angle θ from the front of the boom 32, the distance H (see FIG. 4) between the left and right center of the front outrigger device 33 and the left and right center of the rear outrigger device 37, or the crane device It is preferable that the threshold value is calculated using at least one of the suspended load Wt of the suspended loads actually suspended by the 26 hooks 34. Furthermore, it is preferable that all of the above parameters are not fixed values but numerical values determined in consideration of the state of the crane device 26.

  The working radius R of the boom 32 can be calculated from the detection values of the boom length detector 15 and the boom undulation angle detector 17. The turning angle θ from the front front of the boom 32 can be obtained from the detection value of the boom turning angle detector 16. The distance H between the left and right center of the front outrigger device 33 and the left and right center of the rear outrigger device 37 is determined from the type of the loadable truck crane 10 to be used. Further, the suspended load Wt of the suspended load that is actually suspended from the hook 34 of the crane device 26 can be calculated using the detected value of the undulating support force detector 18.

  More preferably, the threshold value is calculated from the following calculation formula.

(Equation 1)
Ft = (N−1) · R · (cos θ) · Wt / H

Ft: threshold N: safety factor R: working radius θ: turning angle Wt from the front front direction of the boom 32: hanging load of the crane device H: left-right center of the front outrigger device 33 and left-right center of the rear outrigger device 37 Distance between

  Here, the safety factor N is determined in advance considering that the suspended load may vibrate when the suspended load Wt is lifted. For example, when a suspended load with a rated load is suspended, the suspended load vibrates, and 1.27 times the rated load acts on the load-type truck crane, and the ground reaction force of the rear jack 39 becomes zero. At this time, the safety factor N is 1.27. As the safety factor N, a numerical value that does not cause the loadable truck crane 10 to fall over is used.

  In S04, the case where the control device 12 determines that the value of the ground reaction force signal is equal to or less than the threshold is described. This includes the case where the sum of the ground reaction forces of the two rear jacks 39 is less than or equal to the threshold value, or only one of the two rear jacks 39 is less than or equal to the threshold value. Preferably, the value of the ground reaction force signal from the reverse jack 39 on the reverse side is more than a threshold value.

  As described above, the control device 12 regulates the operation of the crane device 26 based on the ground reaction force signal from the rear jack 39, so that the work capacity in the front region is limited with a large margin. It is not carried out with a load, and the work capacity in the front area is not limited too much. For this reason, while ensuring the safety of work, the capacity of the crane device 26 can be maximized, and the work capacity of the load-type truck crane 10 is improved.

  The threshold Ft for regulating the operation of the crane device 26 is at least the working radius R of the boom 32, the turning angle θ from the front front of the boom 32, the suspended load Wt of the crane device 26, the rear outrigger device 37 and the front outrigger device 33. Since the operation of the crane device 26 is limited by a threshold value that matches the actual operation of the crane device 26, the work capacity of the load-type truck crane is further increased. improves.

  Since the threshold value Ft is calculated in consideration of the safety factor N, it is possible to maximize the capacity of the load-type truck crane 10 while ensuring the safety of work.

  In this embodiment, the suspended load Wt is calculated by using the undulation support force detector 18 which is a differential pressure gauge provided in the boom 32 undulation cylinder. For example, a numerical value obtained by measuring the tension of the wire with a load cell. It may be calculated using

DESCRIPTION OF SYMBOLS 10 Loading type truck crane 12 Control apparatus 13 Ground reaction force measuring device 26 Crane apparatus 27 Driver's cab 28 Car bed 37 Rear outrigger apparatus 39 Rear jack

Claims (4)

A load-type truck crane provided with a crane device between a cab and a loading platform,
The load-type truck crane includes a front outrigger device and a rear outrigger device respectively provided at the front and rear of the vehicle body,
Rear jacks respectively provided at left and right outer ends of the rear outrigger device;
A control device for receiving a ground reaction force signal of the rear jack;
An alarm device connected to the control device;
Is provided,
The control device activates at least the function of restricting the operation of the crane device or the alarm device based on the ground reaction force signal when a boom constituting the crane device is located in a front region. Work any of the functions,
A load-type truck crane characterized by that. The ground reaction force signal from the rear jack is
It is a signal indicating the reaction force from the ground reaction force measuring device provided in the rear jack,
The load-type truck crane according to claim 1. The control device includes:
When the value of the ground reaction force signal falls below a threshold value, at least one of the function of regulating the operation of the crane device or the function of operating the alarm is activated,
The threshold value is calculated using at least one of a working radius of the boom, a turning angle of the boom, a suspended load of the crane device, and a distance between the rear outrigger device and the front outrigger device.
The load-type truck crane according to claim 1 or 2, characterized by the above-mentioned. When the threshold is Ft,
Ft is (N−1) · R · (cos θ) · Wt / H (N: safety factor, R: working radius of the boom, θ: turning angle from the front front of the boom, Wt: of the crane device. Suspended load, H: distance between the rear outrigger device and the front outrigger device),
The load-type truck crane according to claim 3.

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