JP2021038082A - Loading-type truck crane - Google Patents

Abstract

To provide a load-type truck crane that can maximize the capacity of the crane equipment while ensuring the safety of the work, without overly restricting the work capacity in the forward area.SOLUTION: A load-type truck crane 10 is equipped with an outrigger device 33, a load detector 13 that detects a load applied to a rear wheel 23, a control unit 12, and an alarm 14. The control unit 12 works, based on the load signal, at least one of the functions of regulating the operation of the crane equipment 21 and activating the alarm 14 when a boom 32, which constitutes the crane equipment 21, is located in the forward area. This configuration reduces the limitation of work capacity in the forward area. As a result, the work capacity of the load-type truck crane 10 can be improved by maximizing the capacity of the crane equipment 21 while ensuring the safety of the work.SELECTED DRAWING: Figure 1

Description

The present invention relates to a loaded truck crane. More specifically, the present invention relates to a loaded truck crane in which outriggers are provided in the vicinity of the crane device. In this specification, the description of front / rear / left / right is defined as front / rear / left / right with reference to the user of the loaded truck crane in the driver's cab of the vehicle body.

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

In a loaded truck crane, an outrigger device is provided on the vehicle body in order to ensure the stability of the vehicle body during crane work. When performing the crane work, the user of the loaded truck crane performs the work with the outriggers constituting the outrigger device protruding from the vehicle body.

The rated load of a loaded truck crane is based on the ability at the turning position (stability when empty) and the strength of the crane structure when there is no load on the loading platform and the stability is the worst in the lateral area. It is calculated from the determined capacity (crane strength performance). The graph of FIG. 3 of Patent Document 1 is an example of the rated load calculated in this way, and 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. The configuration to be used is disclosed.

Japanese Unexamined Patent Publication No. 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 where the stability is the worst in the lateral region, there is a margin for the safety side. The cost is very large. Further, in the front region of the loaded truck crane, the rated load of the crane device is set to 25% in consideration of its structure. Then, there is a problem that the rated load of the loaded truck crane is excessively limited particularly in the front region.

Further, the load-type truck crane has a structure in which a loading platform is installed behind the crane device due to its structure, but the rated load is premised on a state in which no load is placed on this loading platform. Then, when there is a load on the loading platform, the load is on the rear side of the outrigger device, which increases the stability of the loaded truck crane and relaxes the restrictions in the front area so that it is close to the crane strength performance. Should be. However, since the method for calculating the rated load in the front region is as described above, there is a problem that the limitation in the front region is excessive in this respect as well.

In view of the above circumstances, the present invention provides a loaded truck crane capable of maximizing the capacity of a crane device while ensuring work safety without overloading the work capacity in the front region. The purpose is to do.

The load-type truck crane of the first invention is a load-type truck crane in which a crane device is provided between an cab and a loading platform, and the load-type truck crane has the cab when viewed from the side. An out-trigger device located between the loading platform, a load detector that detects the load applied to the rear wheels of the loaded truck crane, a control device that receives a load signal from the load detector, and the like. An alarm device connected to the control device is provided, and the control device is provided with at least the crane device based on the load signal when the boom constituting the crane device is located in the front region. It is characterized by activating either a function of restricting operation or a function of activating the alarm.
The load-bearing truck crane of the second invention is characterized in that, in the first invention, the load detector is provided on the axle of the rear wheel.
In the first or second invention, the load-bearing truck crane of the third invention has the function of restricting the operation of the crane device at least when the value of the load signal falls below the threshold value, or the above-mentioned control device. One of the functions for activating the alarm is activated, 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, or the distance between the rear wheel and the outrigger device. It is characterized in that it is calculated using a crane.
In the third invention, the load-bearing truck crane of the fourth invention has Ft of (N-1), R, (cosθ), Wt / H (N: safety factor, R:) when the threshold value is Ft. It is characterized in that it is calculated by the working radius of the boom, θ: the turning angle from the front front of the boom, Wt: the suspended load of the crane device, H: the distance between the rear wheel and the outrigger device). And.

According to the first invention, the control device regulates the operation of the crane device based on the load signal of the load applied to the rear wheels, so that the limitation of the working capacity in the front region provides a large margin. It is not performed under the rated load, and the limitation of working capacity in the front area is suppressed. Therefore, while ensuring work safety, the capacity of the crane device can be maximized, and the work capacity of the loaded truck crane is improved.
According to the second invention, since the load detector is provided on the axle of the rear wheel, the load can be grasped with high accuracy by a simple method, so that the safety of work can be improved.
According to the third invention, the threshold for regulating the operation of the crane device is at least one of the working radius of the boom, the turning angle of the boom, the suspended load of the crane device, and the distance between the rear wheel and the out trigger device. Since the operation of the crane device is limited by a threshold value that matches the actual operation of the crane device, the working capacity of the loaded truck crane is further improved.
According to the fourth invention, since the threshold value 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 which concerns on 1st Embodiment of this invention. It is a rear view around the rear wheel of the loading type truck crane of FIG. It is a hydraulic circuit diagram of the loading type truck crane of FIG. It is a control circuit diagram of the loading type truck crane of FIG. It is explanatory drawing of the work area of the loading type truck crane of FIG. It is an operation flow diagram 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 embodiments shown below exemplify a loaded truck crane for embodying the technical idea of the present invention, and the present invention does not specify the loaded truck crane to the following. The size or positional relationship of the members shown in each drawing may be exaggerated to clarify the explanation.

<First Embodiment>
(Loading type truck crane 10)
FIG. 1 shows a side view of the loaded truck crane 10 according to the first embodiment of the present invention. As shown in FIG. 1, the load-type truck crane 10 has a crane device 21 mounted on a vehicle frame 29 between a driver's cab 27 and a loading platform 28 of a general-purpose truck 20. The general-purpose truck 20 is provided with front wheels 22 symmetrically. Further, the general-purpose truck 20 is provided with the rear wheels 23 symmetrically.

FIG. 2 shows a rear view of the vicinity of the rear wheels 23 of the loaded truck crane 10 according to the present embodiment. In FIG. 2, members other than those around the rear wheel 23 are omitted. In the present embodiment, two rear wheels 23 are provided on each of the left and right sides, and are supported by the axle 24. The axle 24 is provided with one load detector 13 on each of the left and right sides to detect the load applied to the rear wheels 23.

As shown in FIG. 1, the crane device 21 is provided on a base 30 fixed on a vehicle frame 29, a post 31 provided so as to be rotatable with respect to the base 30, and undulatingly provided on an upper end portion of the post 31. The boom 32 and an outrigger device 33 provided on the base 30 and projecting outward from the base 30 to the left and right are provided. That is, the outrigger device 33 is located between the driver's cab 27 and the loading platform 28 when viewed from the side surface. Hydraulic jacks 38 are provided at the left and right tips of the outrigger device 33 (see FIG. 5).

The post 31 has a built-in winch. A wire rope is guided from this winch to the tip of the boom 32 and hung around the hook 34 via a pulley at the tip of the boom 32 to suspend the hook 34 from the tip of the boom 32.

The crane device 21 is hydraulically driven by the hydraulic circuit 40. Lever groups 35 for operating the hydraulic circuit 40 are provided on both the left and right sides of the base 30. Further, a control device 12 for electrically controlling the hydraulic circuit 40 and controlling the work vehicle is provided on the base 30.

(Flood control circuit 40)
FIG. 3 shows a hydraulic circuit diagram of the loading type truck crane 10 according to the present embodiment. As shown in FIG. 3, the hydraulic circuit 40 of the crane device 21 mainly includes a hydraulic valve unit 41, a hydraulic pump 43 that supplies hydraulic oil in a tank 42 to the hydraulic valve unit 41, a hydraulic pump 43, and a hydraulic valve. The main oil passage 44 connecting the unit 41, the return oil passage 45 connecting the hydraulic valve unit 41 and the tank 42, the undulating operation of the crane device 21, the expansion and contraction operation of the boom 32, the turning operation of the boom 32, and the winch. It is configured to include a plurality of crane device actuators 46 and two jacks 38 for hoisting and lowering. The crane device actuator 46 and the jack 38 are connected to the hydraulic valve unit 41.

The hydraulic pump 43 is connected to the engine 36 of the general-purpose truck 20 via a PTO (power take-off) device, and is driven by the engine 36.

The hydraulic valve unit 41 is provided with a boom turning control valve 47a, a boom expansion / contraction control valve 47b, a boom undulating control valve 47c, a winch control valve 47d, a right jack control valve 48a, and a left jack control valve 48b. .. The boom turning control valve 47a is used for the boom turning actuator 46a, the boom expansion / contraction control valve 47b is used for the boom expansion / contraction actuator 46b, the boom undulating control valve 47c is used for the boom undulating actuator 46c, and the winch control valve 47d is used for the winch control valve 47d. It is connected to each of the winch hydraulic motors 46d. The right jack control valve 48a is connected to the jack 38 located on the right side, and the left jack control valve 48b is connected to the jack 38 located on the left side.

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

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

(Control circuit)
FIG. 4 shows a control circuit diagram of the loaded truck crane 10 according to the present embodiment. On the input side of the control device 12, two load detectors 13, a boom length detector 15, a boom swivel angle detector 16, a boom undulation angle detector 17, and an undulation bearing force detector 18 are electrically connected. Is 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 undulating control valve 47c, a right jack control valve 48a, and a left jack control valve 48b are electrically connected. It is connected to the. A predetermined value as a distance between the rear wheels 23 and the outrigger device 33 can be input to the control device 12 according to the model of the loaded truck crane 10.

The boom length detector 15 is for detecting the length of the boom 32, and is, for example, a cord feeding length detector. The cord feeding length detector detects the feeding length of the length measuring cord by detecting the amount of rotational displacement 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 root side of the post 31. For example, the boom turning angle detector 16 is a potentiometer. A rotary encoder may be used instead of this potentiometer.

The boom undulation angle detector 17 is for detecting the undulation angle of the boom 32, and is arranged on the root side of the boom 32. For example, the boom undulation angle detector 17 is a potentiometer. A rotary encoder may be used instead of this potentiometer.

As described above, the load detector 13 is provided on the axle 24 that supports the left and right rear wheels 23. In the present embodiment, the load detector 13 includes a strain gauge installed on the axle 24. The load measured by the load detector 13 is output to the control device 12 as a load signal.

Since the load detector 13 is provided on the axle 24 of the rear wheel 23, the load can be grasped with high accuracy by a simple method, so that the work safety can be improved.

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

The undulation bearing capacity detector 18 is provided to detect the load suspended on the hook 34. In the present embodiment, the undulation bearing force detector 18 is a differential pressure gauge provided in the cylinder for undulation of the boom. The differential pressure detected by the undulation bearing capacity detector 18 is output to the control device 12.

(Work area)
FIG. 5 is an explanatory view of a work area of the loading type truck crane 10 according to the present embodiment. FIG. 5 shows a plan view of the loaded truck crane 10. In the present embodiment, the load-type truck crane 10 is provided with an outrigger device 33 in the vicinity of the crane device 21, that is, between the cab 27 and the loading platform 28. The user of the load-type truck crane 10 carries out the work of loading and unloading the load with the outrigger device 33 sufficiently extended to the outside.

In the load-type truck crane 10, the weight of the load that can be safely loaded and unloaded differs depending on the angle in the horizontal plane of the boom 32 that structurally constitutes the crane device 21, that is, the turning angle. Generally, the rated load of the loaded truck crane 10 is set for each of the following three regions, a rear region, a lateral region, and a front region. In the plan view, the rear region may be referred to as the center of rotation of the boom 32 and the left and right centers of the two rear wheels 23 on the left and right (hereinafter, referred to as "right rear wheel center CR" and "left rear wheel center CL"). .) And the area between the lines connecting the two lines (the side with the smaller angle composed of the two lines).

The lateral region is the region between the line segment connecting the center of rotation of the boom 32 and the center CR of the right rear wheel, and the line segment connecting the center of rotation of the boom 32 and the jack 38 on the right side (from two line segments). The area between the line segment connecting the center of rotation of the boom 32 and the center CL of the left rear wheel, and the line segment connecting the center of rotation of the boom 32 and the jack 38 on the left side (the side with the smaller angle) The side with a small angle composed of two line segments).

The front region is a region between the line segments connecting the center of rotation of the boom 32 and the left and right jacks 38 (the side having a small angle composed of the two line segments). In the present embodiment, the three regions are defined as described above, but the definition of this region may differ depending on the configuration of the loaded truck crane 10. Further, since the boundary of each region is determined by the signal from the boom turning angle detector 16, the position may be strictly different from the position defined above.

(Operation flow)
FIG. 6 shows an operation flow chart of the loaded truck crane 10 according to the present embodiment. The control device 12 of the loading type 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 referred to as S01).

In S02, the control device 12 determines whether or not the boom 32 is located in the front region. If 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, so that the control device 12 proceeds to S03.

In S03, the control device 12 acquires a load signal from the load detector 13 provided on the axle 24. If the control device 12 determines in S04 that the numerical value of the load is equal to or less than the threshold value, the control device 12 proceeds to S05.

In S05, the control device 12 uses a boom turning control valve 47a or the like to regulate the operation of the crane device 26 in the front region. Specifically, the undulating operation of the boom 32 is stopped, or the turning operation of the boom 32 is stopped. In addition, the control device 12 may perform operation restrictions that slow down these operation speeds. Together with this operation regulation, the control device 12 activates the alarm device 14 to make the user of the loaded truck crane 10 aware that the operation regulation has been applied in the front region. Further, the control device 12 may operate only the alarm device 14.

When the control device 12 determines in S04 that the numerical value of the load is larger than the threshold value, the control device 12 does not regulate the operation of the crane device 26 in the front region in S05.

(Calculation method of threshold value Ft)
The control device 12 determines in S04 whether the value of the load signal is equal to or less than the threshold value Ft. The threshold value Ft 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 front of the boom 32, the distance H between the left and right centers of the outrigger device 33 and the left and right centers of the rear wheels 23 (see FIG. 5), or the crane device 26. It is preferable that the threshold value Ft is calculated by using at least one of the suspended load Wt of the suspended load actually suspended on the hook 34. Further, 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-right center of the outrigger device 33 and the left-right center of the rear wheel 23 is determined from the model of the loaded truck crane 10 used. Further, the suspended load Wt of the suspended load actually suspended on the hook 34 of the crane device 26 can be calculated by using the detection value of the undulation bearing capacity detector 18.

More preferably, the threshold value Ft is calculated from the following formula. However, it is not limited to this calculation formula.

[Number 1]
Ft = (N-1) ・ R ・ (cosθ) ・ Wt / H

Ft: Threshold N: Safety factor R: Working radius θ: Turning angle from the front front direction of the boom 32 Wt: Suspended load of the crane device 26 H: Left and right center of the outrigger device 33 and left and right center of the rear wheel 23 Distance between

Here, the safety factor N is determined in advance in consideration of the fact that the suspended load may vibrate when the suspended load Wt is lifted. For example, when a suspended load having a rated load is suspended, it is considered that the suspended load vibrates and 1.27 times the rated load acts on the loaded truck crane 10, and the load on the rear wheels 23 becomes zero. At this time, the safety factor N is 1.27. As the safety factor N, a numerical value is used in which the loaded truck crane 10 does not tip over.

In S04, the case where the control device 12 determines that the value of the load signal is equal to or less than the threshold value Ft is described. This includes the case where the total load of the two load detectors 13 is equal to or less than the threshold value Ft, or the total load of the two load detectors 13 is equal to or less than the threshold value Ft. Preferably, the value of the load signal from the load detector 13 on the inverted side is preferably the threshold value Ft or more.

As described above, the control device 12 regulates the operation of the crane device 21 based on the load signal of the load applied to the rear wheels 23, so that the limitation of the working capacity in the front region provides a large margin. It is not performed at the rated load, and the limitation of working capacity in the front area is suppressed. Therefore, while ensuring work safety, the capacity of the crane device 26 can be maximized, and the work capacity of the loaded truck crane 10 is improved.

The threshold Ft that regulates the operation of the crane device 21 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, and between the rear wheels 23 and the out trigger device 33. Since the operation of the crane device 26 is restricted by the threshold value Ft that matches the actual operation of the crane device 26 by being calculated using any of the distances H of the above, the working capacity of the loaded truck crane 10 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 loaded truck crane 10 while ensuring the safety of work.

In the present embodiment, the suspended load Wt is calculated by using the undulation bearing force detector 18, which is a differential pressure gauge provided on the cylinder for undulating the boom 32. It may be calculated using.

In the present embodiment, two load detectors 13 are provided on the axle 24, but the present embodiment is not limited to this. The load detector 13 may be one. Further, it may be provided on a leaf spring provided on the axle 24 or may be provided on a shock absorber.

10 Loading type truck crane 12 Control device 13 Load detector 14 Alarm 21 Crane device 27 Driver's cab 28 Loading platform 32 Boom 33 Outrigger device

Claims (4)

It is a loading type truck crane equipped with a crane device between the cab and the loading platform.
The load-type truck crane includes an outrigger device located between the driver's cab and the loading platform when viewed from the side.
A load detector that detects the load applied to the rear wheels of the loaded truck crane, and
A control device that receives a load signal from the load detector,
An alarm connected to the control device and
Is provided,
The control device has a function of regulating at least the operation of the crane device or a function of activating the alarm device based on the load signal when the boom constituting the crane device is located in the front region. Make one work,
A loading type truck crane characterized by that. The load detector
Provided on the axle of the rear wheel,
The load-type truck crane according to claim 1. The control device is
When the value of the load signal falls below the threshold value, at least either the function of restricting the operation of the crane device or the function of activating the alarm is activated.
The threshold value is calculated using at least one of the working radius of the boom, the turning angle of the boom, the suspended load of the crane device, and the distance between the rear wheel and the outrigger device.
The load-type truck crane according to claim 1 or 2. When the threshold value is Ft,
Ft is (N-1), R, (cosθ), 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 wheel and the outrigger device)
The loaded truck crane according to claim 3.