Interference prevention device for aerial work platforms

Abstract

To provide an interference prevention device for aerial work platforms that can improve work efficiency while preventing interference with vehicle structures and other components. [Solution] The interference prevention device includes an area setting unit 103 that sets an interference prevention area to prevent the boom from interfering with the vehicle body and structures provided on the vehicle body, and a regulating unit 104 that determines whether the boom position calculated by the position calculation unit 101 has reached the interference prevention area set by the area setting unit 103, and if it is determined that the boom position has reached the interference prevention area, regulating the operation of the boom, and the area setting unit 103 varies the interference prevention area according to the amount of operation of the slewing operation lever 42 and the luffing operation lever 43.

Description

Technical Field

[0001] The present invention relates to an interference prevention device for an aerial work vehicle that prevents a boom from interfering with a structure or the like provided on a vehicle body.

Background Art

[0002] As an example of an aerial work vehicle, it includes a vehicle body capable of traveling with a driver's cab at the front, a boom disposed on the vehicle body so as to be capable of起伏, telescoping, and swiveling, and a work platform for workers provided at the tip of the boom. An operator on the work platform operates an operating device to operate the boom, thereby configuring the work platform to be movable to an arbitrary high position. It is known to be used for various high-altitude operations such as electrical wire work, building construction, highway construction, etc. (for example, refer to Patent Document 1).

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] In such an aerial work vehicle, structures such as toolboxes, boarding steps, and handrails are installed on the vehicle body. Therefore, when the boom is swiveled in a state where the起伏 angle of the boom is low (for example, near the storage position of the boom), there is a risk that the boom will interfere with the driver's cab or the structures on the vehicle body. Therefore, conventionally, an interference prevention area (intrusion regulation area) is set around these structures, and when the boom enters the interference prevention area, a device (interference prevention device) that regulates the operation of the boom has been put into practical use.

[0005] In conventional technology, when the boom is retracted onto the vehicle body, the interference prevention area is fixed and considerably wide in the direction of rotation (lateral direction) due to the placement of structures and other objects near the side of the boom (near the direction of rotation). As a result, when the boom is rotated near or above the retracted position, the boom easily enters the interference prevention area. Therefore, with conventional technology, the boom cannot be rotated towards the work object until it has been raised and retracted from the retracted position to a certain height (sufficiently higher than the interference prevention area), which resulted in poor work efficiency.

[0006] This invention has been made in view of the above problems, and aims to provide an interference prevention device for aerial work platforms that can improve work efficiency while preventing interference with the structure of the vehicle, etc. [Means for solving the problem]

[0007] To solve the above problems, the interference prevention device for a high-altitude work vehicle according to the present invention comprises a drivable vehicle body, a boom provided on the vehicle body and configured to be able to raise and lower and rotate, with its tip facing forward or backward and stored in a predetermined storage position on the vehicle body, a boom operating device (for example, an upper operating device 41 in the embodiment) for operating the boom, a position detection unit (for example, a position calculation unit 101 and each detector 91-93 in the embodiment) for detecting the position of the boom, an operation control unit for operating the boom in response to the operation of the boom operating device, an area setting unit for setting an interference prevention area to prevent the boom from interfering with the vehicle body and structures provided on the vehicle body, and a regulating unit that determines whether the position of the boom detected by the position detection unit has reached the interference prevention area set by the area setting unit, and if it is determined that the position of the boom has reached the interference prevention area, regulating the operation of the boom, wherein the area setting unit varies the interference prevention area according to the amount of operation of the boom operating device.

[0008] In the interference prevention device for the aerial work platform having the above configuration, the interference prevention area has an interference area which corresponds to the vehicle body and the structure, and a margin area set around the interference area, and it is preferable that the area setting unit varies the margin area according to the amount of operation of the boom operating device.

[0009] Furthermore, in the interference prevention device for the aerial work platform having the above configuration, the boom operating device has a boom rotation operating unit (for example, a rotation operating lever 42 in the embodiment) for operating the boom to rotate, and a boom luffing operating unit (for example, a luffing operating lever 43 in the embodiment) for operating the boom to raise and lower, and it is preferable that the restricting unit, when it determines that the boom has reached the interference prevention area while the boom rotation operating unit and the boom luffing operating unit are operated to raise and lower the boom, restricts the rotation operation in the predetermined direction while allowing the raising and lowering operation.

[0010] Furthermore, in the interference prevention device for the aerial work platform having the above configuration, when the boom is rotating due to the operation of the boom rotation operation unit, it is preferable that the margin area is set to be smaller the smaller the amount of operation of the boom rotation operation unit is.

[0011] Furthermore, in the interference prevention device for the aerial work platform having the above configuration, it is preferable that the area setting unit sets the margin area smaller as the amount of operation of the boom luffing operation unit increases when the boom is being raised or lowered by the operation of the boom luffing operation unit. [Effects of the Invention]

[0012] According to the interference prevention device for aerial work platforms of the present invention, by varying the interference prevention area provided around the vehicle's structure, etc., according to the amount of operation of the boom operating device, the range of motion of the boom (the range in which it can be rotated) can be secured without imposing excessive restrictions on the operation of the boom. As a result, the boom can be moved in the desired direction while preventing interference with the vehicle's structure, etc. (the work platform can be efficiently brought closer to the desired position), making it possible to improve work efficiency while ensuring work safety.

[0013] Furthermore, according to the interference prevention device for aerial work platforms of the present invention, the interference prevention area is set as an area with a margin area added to the interference area, and the margin area, which is an additional area, is varied according to the amount of operation of the boom operating device. This prevents the setting (variable setting) of the interference prevention area from becoming complicated, and makes it possible to achieve both work safety and work efficiency without requiring complex interference control.

[0014] Furthermore, according to the interference prevention device for aerial work platforms of the present invention, when the boom is rotated in a predetermined direction while the boom is raised by simultaneously operating the boom rotation control unit and the boom luffing control unit, if it is determined that the boom has reached the interference prevention area, the rotation operation in the predetermined direction is restricted while the luffing operation is permitted. This makes it possible to maximize the range of motion (range in which the boom can rotate) of the boom and bring the work platform closer to the work object, thereby improving the usability of the aerial work platform.

[0015] Furthermore, according to the interference prevention device for aerial work platforms of the present invention, by setting the margin area to be smaller as the amount of operation of the boom slewing control unit decreases, for example, even when the boom's elevation angle is low (near and above the stowed position), the boom can be brought closer to the interference area side (vehicle structure side, etc.) by keeping the boom's slewing speed low, thereby substantially expanding the range of motion (range in which the boom can be slewing) of the boom and further improving work efficiency. On the other hand, by setting the margin area to be larger as the amount of operation of the boom slewing control unit increases, for example, when the boom's elevation angle is low (near and above the stowed position), interference with structures, etc., when the boom is slewing at high speed can be reliably prevented, thereby improving work safety.

[0016] Furthermore, according to the interference prevention device for aerial work platforms of the present invention, by setting the margin area to decrease as the amount of operation of the boom luffing control unit increases, when the boom is being raised and lowered, increasing the luffing speed (raising and lowering speed) simultaneously allows the boom to rotate and move closer to the interference area side (vehicle structure side, etc.). This substantially expands the range of motion (range in which it can rotate) of the boom, making it possible to efficiently bring the work platform closer to the work object. [Brief explanation of the drawing]

[0017] [Figure 1] This is a side view of the aerial work platform according to this embodiment. [Figure 2] This is a functional block diagram of the interference prevention device according to this embodiment. [Figure 3] This is a schematic diagram illustrating the interference prevention area. [Figure 4] This is a schematic diagram illustrating the margin area of ​​the interference prevention region described above. [Figure 5] (A) is a schematic diagram showing the relationship between the amount of elevation control and the margin area, and (B) is a schematic diagram showing the relationship between the amount of rotation control and the margin area. [Figure 6] This is a schematic diagram showing the state in which the boom of the above-mentioned aerial work platform has reached the above-mentioned interference prevention area. [Figure 7]It is a schematic diagram for explaining the operation of the interference prevention device, showing the state where the boom is in the stowed position. [Figure 8] It is a schematic diagram for explaining the operation of the interference prevention device, showing the state where the boom is being raised and lowered. [Figure 9] It is a schematic diagram for explaining the operation of the interference prevention device, showing the state where the boom is being swung. [Figure 10] It is a schematic diagram for explaining the operation of the interference prevention device, showing the state where the boom is being swung while being raised and lowered. [Figure 11] It is a schematic diagram for explaining the operation of the interference prevention device, showing the state where the boom is moved to a predetermined high position.

Embodiments for Carrying out the Invention

[0018] Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. The aerial work platform 1 according to this embodiment is shown in FIG. 1. First, the overall configuration of the aerial work platform 1 will be described with reference to FIG. 1. In the following description, the longitudinal direction of the aerial work platform 1 will be referred to as the front-rear direction, the lateral direction will be referred to as the left-right direction, and the vertical direction will be referred to as the up-down direction.

[0019] As shown in FIG. 1, the aerial work platform 1 is configured based on a truck vehicle having a cab 7 at the front of the vehicle body 2 and capable of traveling by a pair of left and right tire wheels 5 (front wheels 5f and rear wheels 5r) disposed at the front and rear of the vehicle body 2. The vehicle body 2 includes a chassis frame on which the tire wheels 5 (front wheels 5f and rear wheels 5r) are disposed, and a sub-frame attached on this chassis frame.

[0020] The vehicle body 2 is equipped with jacking devices 10 on the front, rear, left, and right sides to lift and support the vehicle body 2 during work at height. The jacking devices 10 consist of a pair of front jacks 10f positioned behind the front wheels 5f and a pair of rear jacks 10r positioned behind the rear wheels 5r. Each jack 10f, 10r extends downward by driving a jack cylinder 11 (see Figure 2) located inside it, thereby lifting and supporting the vehicle body 2 and stabilizing the entire vehicle. At the rear end of the vehicle body 2 is a lower operating device 27 equipped with various operating levers (not shown) for boom operation, similar to the upper operating device 41 described later, and a jack operating lever 28 (see Figure 2) for extending and retracting the jacking devices 10.

[0021] In the mounting area behind the driver's cabin 7 on the vehicle body 2, a slewing platform 20 is provided, which is driven by a slewing motor 24 (see Figure 2) and is configured to rotate horizontally around its vertical axis. The base end of the boom 30 is attached to this slewing platform 20 via a foot pin 22 so that it can swing (raise and lower) in the vertical direction.

[0022] The boom 30 has a configuration in which a base boom 30a, an intermediate boom 30b, and a tip boom 30c are nested together in order from the turntable 20 side. The boom 30 can be extended and retracted in the axial direction (longitudinal direction) by the extension and retraction drive of the telescopic cylinder 31 (see Figure 2) located inside. In addition, a luffing cylinder 23 is mounted between the base boom 30a and the turntable 20, and by driving the extension and retraction of this luffing cylinder 23, the entire boom 30 can be raised and lowered in the upper and lower planes (vertical plane). On the vehicle body 2, a boom rest (boom support) 39 is erected and positioned directly behind the driver's cabin 7 to abut against the lower surface of the boom 30 when it is fully retracted and tilted downwards, in order to store and hold the boom 30.

[0023] A vertical post (not shown) is pivotally supported at the tip of the tip boom 30c so as to be able to swing up and down. This vertical post is controlled to maintain a vertical position at all times, regardless of the elevation angle of the boom 30, by an upper leveling cylinder (not shown) straddling the tip of the tip boom 30c and a lower leveling cylinder (not shown) straddling the base boom 30a and the turntable 20. A work platform 40 for worker use is attached to this vertical post via a work platform bracket (not shown). A swivel motor 34 (see Figure 2) is provided inside this work platform bracket, and by rotating this swivel motor 34, the entire work platform 40 can be made to swivel around the vertical post (horizontal rotation). Here, as described above, the vertical post is always kept in a vertical position, and as a result, the floor surface of the work platform 40 is always kept horizontal regardless of the elevation angle of the boom 30.

[0024] The work platform 40 is equipped with an upper operating device 41 operated by an operator riding on it. As shown in Figure 2, the upper operating device 41 includes a slewing lever 42 for slewing the boom 30 (slewing platform 20), a luffing lever 43 for luffing the boom 30, an extension lever 44 for extending and retracting the boom 30, and a swivel lever 45 for swiveling the work platform 40. When not in operation, these operating levers 42 to 45 are held in a neutral position with the levers facing vertically, and are configured to be tiltable in a direction determined according to each operating lever 42 to 45 relative to this neutral position. The operating state of each operating lever 42 to 45 (direction of operation and amount of operation relative to the neutral position) is detected by an operation detector such as a potentiometer, and the detection signal is input to the controller 100 described later as an operation signal corresponding to the operating state of each operating lever 42 to 45 (direction of operation and amount of operation relative to the neutral position). In this way, a worker on the work platform 40 can operate various functions such as the rotation of the boom 30 (slewing platform 20) (rotational drive of the slewing motor 24), the luffing of the boom 30 (extension and retraction drive of the luffing cylinder 23), the extension and retraction of the boom 30 (extension and retraction drive of the extension cylinder 31), and the swivel operation of the work platform 40 (rotational drive of the swivel motor 34) by operating the respective operating levers 42 to 45 of the upper operating device 41.

[0025] As shown in Figure 2, the operating mechanism of the jacking device 10 (jacks 10f, 10r) and the high-altitude work equipment (swivel platform 20, boom 30, work platform 40, etc.) installed on the vehicle body 2 is configured to include a controller 100 that receives operation signals from the upper operating device 41 and the lower operating device 27 and controls each hydraulic actuator such as the jack cylinder 11, swivel motor 24, luffing cylinder 23, telescopic cylinder 31, and swivel motor 34, and a hydraulic unit 50 that supplies hydraulic fluid to drive these hydraulic actuators.

[0026] The operation signals output by the operation of the upper operating device 41 or the lower operating device 27 are input to the controller 100. The operation control unit 102 of the controller 100 outputs a command signal corresponding to the operation signal to the hydraulic unit 50 (control valve 53).

[0027] The hydraulic unit 50 comprises a hydraulic tank 51 for storing hydraulic fluid, a hydraulic pump 52 that discharges hydraulic fluid when driven by the power of the engine E mounted on the vehicle body 2, and a control valve 53 that controls the direction and amount of hydraulic fluid supplied from the hydraulic pump 52 to each hydraulic actuator. A power take-off mechanism (PTO) is incorporated into the transmission that transmits the power of the engine E to the tire wheels 5. When the PTO operating lever 55 located in the driver's cabin 7 is operated from the OFF position to the ON position, the power take-off mechanism (PTO) switches the target of the engine E's drive from the tire wheels 5 to the hydraulic pump 52, and the hydraulic pump 52 is driven by the power of the engine E. On the other hand, when the PTO operating lever 55 is operated from the ON position to the OFF position, the power take-off mechanism (PTO) switches the target of the engine E's drive from the hydraulic pump 52 to the tire wheels 5, and the tire wheels 5 are rotated by the power of the engine E.

[0028] The control valve 53 includes an electromagnetic proportional control valve V1 corresponding to the jack cylinder 11, an electromagnetic proportional control valve V2 corresponding to the slewing motor 24, an electromagnetic proportional control valve V3 corresponding to the luffing cylinder 23, an electromagnetic proportional control valve V4 corresponding to the telescopic cylinder 31, and an electromagnetic proportional control valve V5 corresponding to the swivel motor 34. Based on command signals from the operation control unit 102 of the controller 100, the control valve 53 electromagnetically drives the spools of each electromagnetic proportional control valve V1 to V5 to control the supply direction and amount of hydraulic fluid supplied from the hydraulic pump 52 to each hydraulic actuator, and controls the drive direction and drive speed of each hydraulic actuator (controlling the operating direction and operating speed of the jack device 10 and the high-altitude work device). The operation control unit 102 of the controller 100 outputs command signals corresponding to the operation signals (operating direction and amount) to the corresponding control valves V1 to V5 when operation signals are input from each operating lever 28, 42 to 45. Furthermore, the amount of operation of each control lever 28, 42-45 and the output value of the control signal are roughly proportional, and the output value of this control signal and the output value of the command signal to control valves V1-V5 (valve opening, that is, the amount of hydraulic fluid supplied to the hydraulic actuator (the driving speed of each actuator)) are also roughly proportional.

[0029] In the aerial work platform 1 configured as described above, as shown in Figure 1, the boom 30 is fully retracted, then the tip of the boom 30 is rotated to face forward of the vehicle body 2. The work platform 40 is then swung approximately 90 degrees to the left of the boom 30, and the fully retracted boom 30 is lowered and placed on the boom rest 39, thereby putting the boom 30 and work platform 40 into a stored state on the vehicle body 2 (stored state). When the boom 30 and work platform 40 are in the stored state, the tip of the boom 30 and the work platform 40 are positioned near the top surface of the driver's cabin 7. Hereafter, the position in which the boom 30 is in the stored state will be referred to as the "stored position".

[0030] The elevated work platform 1 with this configuration is provided with an access route 60 for workers to get on and off between the retracted work platform 40 and the ground. This access route 60 is configured as a so-called side-entry access route, in which workers get onto the vehicle body 2 from the side (left side) of the vehicle.

[0031] The boarding / alighting path 60 includes a stepped first boarding / alighting step 61 located near the rear wheel 5r on the left side of the vehicle body 2, a stepped second boarding / alighting step 62 located on the left side directly behind the driver's cabin 7, and a step-like third boarding / alighting step 63 located on the left side of the upper surface of the driver's cabin 7. Each boarding / alighting step 61 to 63 forms a platform for workers to get on and off between the stowed work platform 40 and the ground. Above the first boarding / alighting step 61 is a handrail 64 for workers to grip when using the first boarding / alighting step 61 as a platform. To the left of the second boarding / alighting step 62 is a handrail 65 for workers to grip when using the second boarding / alighting step 62 as a platform. To the left of the third boarding / alighting step 63 is a handrail 66 for workers to grip when using the third boarding / alighting step 63 as a platform. Additionally, each handrail 64-66 also functions as a safety barrier to prevent workers from falling while getting on or off the equipment.

[0032] When a worker on the ground boards the work platform 40, they proceed along the boarding / alighting path 60 in the order of the first boarding / alighting step 61, the second boarding / alighting step 62, and the third boarding / alighting step 63, and finally board the work platform 40. On the other hand, when a worker on the work platform 40 disembarks to the ground, they proceed along the boarding / alighting path 60 in the order of the third boarding / alighting step 63, the second boarding / alighting step 62, and the first boarding / alighting step 61, and finally disembark from the vehicle body 2 to the ground.

[0033] In this embodiment, the boom 30 is configured to rotate 360 ​​degrees in the horizontal plane (fully rotatable). However, when the elevation angle of the boom 30 is low, the rotation range of the boom 30 may include structures on the driver's cabin 7 and the vehicle body 2. That is, when the boom 30 is rotated at a low elevation angle (for example, when the boom 30 is raised from its stowed position and rotated at the same time), the rotating boom 30 may interfere with structures on the driver's cabin 7 and the vehicle body 2 (in this embodiment, this includes the third entry / exit step 63, the second handrail 65, and the third handrail 66). Therefore, the aerial work platform 1 of this embodiment is equipped with an interference prevention device to prevent the boom 30 from interfering with structures on the driver's cabin 7 and the vehicle body 2. An interference prevention area A (see Figure 3, etc.) is set around the driver's cabin 7 and the structures on the vehicle body 2 to restrict the boom 30's entry. In the following, for the sake of clarity, the structures on the driver's cabin 7 and the vehicle body 2 will be collectively referred to as "structures, etc." or "vehicle structures, etc."

[0034] Next, the interference prevention device of this embodiment will be described with additional reference to Figures 2 to 6. In the following, the function of the interference prevention device will be mainly described as the rotation interference prevention function, which prevents interference with the vehicle's structure, etc., when the boom 30 is rotating (including the linked operation of rotation and luffing).

[0035] As shown in Figure 2, the interference prevention device of this embodiment mainly consists of an upper operating device 41, a boom slewing angle detector 91, a boom luffing angle detector 92, a boom extension / retraction amount detector 93, and a controller 100.

[0036] The boom slewing angle detector 91 is installed on the vehicle body 2 and detects the slewing angle of the boom 30 (slewing platform 20) relative to the vehicle body 2. The boom luffing angle detector 92 is installed inside the base boom 30a and detects the luffing angle of the boom 30. The boom extension amount detector 93 is installed at the base end of the base boom 30a and detects the length (extension amount) of the boom 30. Each detector 91 to 93 is electrically connected to the controller 100 and outputs a voltage signal (detection signal) to the controller 100 according to the detected information (slewing angle, luffing angle, extension amount of the boom 30).

[0037] As shown in Figure 2, the controller 100 includes a position calculation unit 101, an operation control unit 102, a region setting unit 103, and a regulation unit 104.

[0038] The position calculation unit 101 calculates the position of the boom 30 relative to the vehicle body 2 based on the slewing angle of the boom 30 detected by the boom slewing angle detector 91 and the luffing angle of the boom 30 detected by the boom luffing angle detector 92. The position of the boom 30 refers to the position of the central axis of the boom 30 (the central axis extending in the longitudinal direction of the boom 30). The position calculation unit 101 also calculates the position of the tip of the boom 30 (which may include the work platform 40) relative to the vehicle body 2 based on the slewing angle of the boom 30 detected by the boom slewing angle detector 91, the luffing angle of the boom 30 detected by the boom luffing angle detector 92, and the length of the boom 30 detected by the boom extension amount detector 93.

[0039] The operation control unit 102 transmits command signals (control signals) corresponding to the operation signals from each operation lever 28, 42-45 to each control valve V1-V5, and electromagnetically drives the spools of each control valve V1-V5, thereby controlling the driving direction and driving speed of each hydraulic actuator and controlling the operation of the jack device 10 and the aerial work equipment (slewing platform 20, boom 30, work platform 40). The operation control of the aerial work equipment (each actuator) when each operation lever 42-45 of the upper operation device 41 is operated will be described below.

[0040] When the slewing lever 42 is tilted to the left from the neutral position, the slewing control valve V2's spool movement direction and valve opening are controlled to control the drive direction and drive speed of the slewing motor 24 so that the boom 30 slewing in a direction (counterclockwise) and operating speed (slewing speed) corresponding to the direction and amount of the operation. On the other hand, when the slewing lever 42 is tilted to the right from the neutral position, the slewing control valve V2's spool movement direction and valve opening are controlled to control the drive direction and drive speed of the slewing motor 24 so that the boom 30 slewing in a direction (clockwise) and operating speed (slewing speed) corresponding to the direction and amount of the operation.

[0041] When the luffing lever 43 is tilted forward from the neutral position, the luffing control valve V3 controls the direction of movement of its spool and valve opening to control the driving direction and driving speed of the luffing cylinder 23 so that the boom 30 performs luffing (upward movement) in an operating direction (luffing direction) and operating speed (luffing speed) corresponding to the direction and amount of operation. On the other hand, when the luffing lever 43 is tilted backward from the neutral position, the luffing control valve V3 controls the direction of movement of its spool and valve opening to control the driving direction and driving speed of the luffing cylinder 23 so that the boom 30 performs luffing (downward movement) in an operating direction (luffing direction) and operating speed (luffing speed) corresponding to the direction and amount of operation.

[0042] When the telescopic operation lever 44 is tilted forward from the neutral position, the movement direction of the spool of the telescopic control valve V4 and the valve opening are controlled to control the drive direction and drive speed of the telescopic cylinder 31 so that the boom 30 extends in an operating direction (extension direction) and operating speed (extension speed) corresponding to the direction and amount of operation. On the other hand, when the telescopic operation lever 44 is tilted backward from the neutral position, the movement direction of the spool of the telescopic control valve V4 and the valve opening are controlled to control the drive direction and drive speed of the telescopic cylinder 31 so that the boom 30 retracts in an operating direction (retraction direction) and operating speed (retraction speed) corresponding to the direction and amount of operation.

[0043] When the swivel operation lever 45 is tilted to the left from the neutral position, the swivel control valve V5's spool movement direction and valve opening are controlled to control the drive direction and drive speed of the swivel motor 34 so that the workbench 40 swivels in a direction (counterclockwise) and operating speed (swivel speed) corresponding to the direction and amount of the operation. On the other hand, when the swivel operation lever 45 is tilted to the right from the neutral position, the swivel control valve V5's spool movement direction and valve opening are controlled to control the drive direction and drive speed of the swivel motor 34 so that the workbench 40 swivels in a direction (clockwise) and operating speed (swivel speed) corresponding to the direction and amount of the operation.

[0044] In this embodiment, the operation of the swivel control lever 42 to the left or right from its neutral position is referred to as "swivel operation," and the amount of operation of the swivel control lever 42 to the left or right from its neutral position is referred to as "swivel operation amount." Furthermore, the operation of the luffing control lever 43 to the forward position from its neutral position is referred to as "luffing operation," and the amount of operation of the luffing control lever 43 to the forward position from its neutral position is referred to as "luffing operation amount."

[0045] As shown in Figure 3, the area setting unit 103 sets and stores an interference prevention area A as an area to prevent the boom 30 from interfering with the vehicle's structures, etc. (an area where the boom 30 should not enter). This interference prevention area A is set around the vehicle's structures, etc. (the driver's cabin 7 and structures on the vehicle body 2), and is set as an area where the operation of the boom 30 is restricted if it enters this area. In other words, this interference prevention area A is an area where the boom 30 may interfere with the structures, etc., if it enters this area, based on the external dimensions of the boom 30, the driver's cabin 7, structures on the vehicle body 2, etc. In this embodiment, the interference prevention area A includes an interference prevention area A set on the left side of the vehicle body 2 (the left side of the boom rest 39) (sometimes referred to as "left side interference prevention area AL") and an interference prevention area A set on the right side of the vehicle body (the right side of the boom rest 39) (sometimes referred to as "right side interference prevention area AR"). For example, the left-side interference prevention area AL is an interference prevention area A set around the third boarding / alighting step 63, the second handrail 65, the third handrail 66, the driver's cabin 7, etc., and the right-side interference prevention area AR is an interference prevention area A set around the driver's cabin 7, an antenna (not shown) provided on the driver's cabin 7, etc.

[0046] Each interference prevention region A(AL,AR), as shown in Figure 3, is composed of an interference region B corresponding to the vehicle's structure, etc., and a margin region M set around the interference region B with a predetermined margin. In other words, each interference prevention region A(AL,AR) is a region formed by adding a margin region M around the interference region B.

[0047] Interference region B is a region corresponding to the vehicle's structure, etc., and may be the spatial area occupied by the structure, etc., or it may be a virtual spatial area roughly partitioned around the outer shape of the structure, etc. This interference region B is demarcated by the boundary surface Bf.

[0048] The margin region M is an area set around the interference region B, taking into account a predetermined margin (the area from the boundary surface Bf of the interference region B to a predetermined distance away). The margin region M is set considering, for example, the swing of the boom 30 due to inertia (moment of inertia), the stopping distance of the boom 30 (the distance from when the boom 30 is decelerated until it stops), and play in the structure, etc. This margin region M is demarcated by the boundary surface Mf.

[0049] As shown in Figure 4, the margin area M is variably set according to the operating speed of the boom 30 (luffing speed Va, slewing speed Vb), that is, according to the amount of operation of the operating levers 42 and 43 (luffing operation amount, slewing operation amount). In other words, in this embodiment, a margin area M of a size corresponding to the luffing operation amount (luffing speed Va) and the slewing operation amount (slewing speed Vb) is set. In Figure 4, the margin area M when it is most expanded is indicated by the symbol "M(max)", and the margin area M when it is most contracted is indicated by the symbol "M(min)".

[0050] Here, the relationship between the operating amounts (lifting amount, rotation amount) of the operating levers 42 and 43 and the margin region M will be explained. In the following, the width of the margin region M refers to the width of the margin region M in the lateral direction (rotation direction) and the vertical direction (lifting direction). In other words, the width of the margin region M is the width between the boundary surface Bf of the interference region B and the boundary surface Mf of the margin region M. In this specification, "large region width" is synonymous with "wide region width," and "small region width" is synonymous with "narrow region width."

[0051] Figure 5(A) shows the relationship between the amount of forward movement of the luffing lever 43 (luffing operation amount) and the margin area M. In the figure, the horizontal axis represents the luffing operation amount (shown as a percentage with the maximum operation amount set to "100%)", and the vertical axis represents the width of the margin area M (shown as a percentage with the maximum width set to "100%)". As shown in Figure 5(A), the area setting unit 103 sets the width of the margin area M to be larger as the luffing operation amount decreases, and to be smaller as the luffing operation amount increases. In other words, the width of the margin area M increases as the luffing speed Va of the boom 30 (see Figure 4) decreases, and the width of the margin area M decreases as the luffing speed Va of the boom 30 (see Figure 4) increases. In other words, in this embodiment, the larger the luffing speed Va of the boom 30 (velocity component in the luffing direction), the weaker the vector component in the rotation direction toward the interference region B (structure, etc.) as a vector component in the direction of movement of the boom 30 (because it becomes more difficult to approach the interference region B which is ahead in the rotation direction). Therefore, the width of the margin region M (especially the width in the rotation direction) is reduced in proportion to the amount of luffing operation. For example, as shown in Figure 5(A), when the amount of luffing operation is 20% or less, the width of the margin region M is set to 100% (max), and when the amount of luffing operation is 100%, the width of the margin region M is set to 20% (min). Note that the range in which the amount of luffing operation is 20% or less is the range in which the width of the margin region M is always constant. When the elevation control lever 43 is operated forward in this manner, a margin area M of width calculated according to the amount of elevation operation is set.

[0052] Figure 5(B) shows the relationship between the amount of leftward or rightward movement of the slewing control lever 42 and the margin area M. In the figure, the horizontal axis represents the amount of slewing movement (shown as a percentage with the maximum movement amount set to "100%)", and the vertical axis represents the width of the margin area M (shown as a percentage with the maximum width set to "100%)". As shown in Figure 5(B), the area setting unit 103 sets the width of the margin area M to be smaller as the amount of slewing movement decreases, and sets the width of the margin area M to be larger as the amount of slewing movement increases. That is, the width of the margin area M decreases as the slewing speed Vb of the boom 30 (see Figure 4) decreases, and the width of the margin area M increases as the slewing speed Vb of the boom 30 (see Figure 4) increases. In other words, in this embodiment, the larger the slewing speed Vb (velocity component in the slewing direction) of the boom 30, the stronger the vector component in the direction of movement of the boom 30 that is directed toward the interference region B (structure, etc.) (making it easier for the boom 30 to approach the interference region B). Therefore, the width of the margin region M (especially the width in the slewing direction) is expanded in proportion to the amount of slewing operation. For example, as shown in Figure 5(B), when the amount of slewing operation is 20% or less, the width of the margin region M is set to 20% (min), and when the amount of slewing operation is 100%, the width of the margin region M is set to 100% (max). Note that the range in which the amount of slewing operation is 20% or less is the range in which the width of the margin region M is always constant. When the slewing operation lever 42 is operated to the left or right in this manner, the margin region M is set to a width calculated according to this amount of slewing operation.

[0053] In this embodiment, in order to prevent the setting of interference prevention area A and the control of interference restrictions from becoming complicated, when the slewing operation lever 42 is operated, both the left and right slewing interference prevention areas A (AL, AR) are uniformly varied regardless of the direction of operation of the slewing operation lever 42 (the slewing direction of the boom 30). However, this is not limited to this, and when the slewing operation lever 42 is operated to the left, only the left interference prevention area AL (interference prevention area A on the side of the boom 30's slewing direction (counter-clockwise direction)) may be varied, and when the slewing operation lever 42 is operated to the right, only the right interference prevention area AR (interference prevention area A on the side of the boom 30's slewing direction (clockwise direction)) may be varied.

[0054] Furthermore, when the luffing operation lever 43 is operated forward and the slewing operation lever 42 is operated left or right simultaneously, that is, when the luffing operation and slewing operation are performed simultaneously, the area setting unit 103 compares the width of the margin area M (candidate margin area) calculated according to the amount of slewing operation with the width of the margin area M (candidate margin area) calculated according to the amount of luffing operation, and selects and sets the margin area M with the larger width.

[0055] In this embodiment, the controller 100 (region setting unit 103) detects the amount of operation of the operating levers 42 and 43 (luffing operation amount, slewing operation amount) at intervals of control cycles, for example, every few milliseconds to tens of milliseconds, and calculates and sets a margin region M (interference prevention region A) with a width corresponding to the detected operation amount. Therefore, the margin region M changes moment by moment in response to the luffing operation and slewing operation.

[0056] The regulating unit 104 compares the position of the boom 30 calculated by the position calculation unit 101 with the interference prevention area A (a margin area M that is variably set according to the luffing and slewing operation amounts) set by the area setting unit 103 to determine whether the boom 30 has reached the interference prevention area A (margin area M). If the regulating unit 104 determines that the boom 30 has reached the interference prevention area A (margin area M), it restricts the operation of the boom 30 in the direction of entering the said interference prevention area A (margin area M). However, as this operation restriction of the boom 30, the regulating unit 104 restricts operation in the direction of entering the interference prevention area A, but does not restrict other operations (for example, operation in the direction away from the interference prevention area A). For example, as shown in Figure 6, when the luffing and raising operation of the boom 30 and the rotation operation in the counterclockwise direction are operated in conjunction, if the boom 30 reaches the left-side interference prevention area AL, the rotation operation in the counterclockwise direction (direction of entry) is restricted, but the luffing operation is allowed to continue. Therefore, the entire operation of the boom 30 is not restricted (it is not completely stopped), and the luffing operation of the boom 30 can continue to be performed before and after reaching the left-side interference prevention area AL (the boom can operate without stopping midway). As a modification, the operation of the boom 30 may be completely stopped once, and then control may be performed to allow the luffing operation in response to a new luffing operation by the operator.

[0057] Next, the operation of the interference prevention device of this embodiment will be explained with reference to Figures 7 to 11. In this embodiment, when starting work at height, the boom 30 stored and held in the boom rest 39 is moved upward to a position above the interference prevention area A (structure, etc.). Here, the work object is assumed to be located to the left of the upper part of the vehicle body. Therefore, in order to efficiently bring the work platform 40 on which the worker is riding closer to the work object, the worker intends to perform luffing and raising operations on the boom 30 and rotation operations in the counterclockwise direction, moving the boom 30 upward from its stored position while gradually moving it to the left. The trajectory of the boom 30 at this time (see the position of point P to point T) and the change in the interference prevention area A are shown in Figures 7 to 11. Note that, for convenience, only the left interference prevention area AL of the left and right interference prevention areas A are shown in Figures 7 to 11.

[0058] First, as shown in Figure 7, the boom 30 is held in a stowed position (see position of point P) resting on the boom rest 39. When the boom 30 is in the stowed position, the rotation of the boom 30 in the left and right directions is restricted to prevent interference with the side walls of the boom rest 39. In this embodiment, when the boom 30 is in the stowed position, the margin area M is not set, but an initial value (fixed value) of the margin area M may be set, for example, the maximum width margin area M(max) or the minimum width margin area M(min).

[0059] Next, as shown in Figure 8, the luffing lever 43 is operated forward to raise the boom 30 from its stowed position (see position of point Q). At this time, if the amount of luffing operation is 20% or less, a margin area M(max) with a width of 100% (maximum width) is set.

[0060] Next, as shown in Figure 9, the slewing lever 42 is operated to the left to rotate the boom 30 counterclockwise (see position of point R). If the amount of slewing at this time is 20% or less, a margin area M(min) with a width of 20% (minimum width) is set. As a result, the margin area M is reduced from the maximum width to the minimum width, and the interference prevention area A(AL) is substantially reduced, so the boom 30 can be rotated in a direction that approaches structures, etc. (counterclockwise), and the boom 30 and work platform 40 can be moved to the left.

[0061] Next, as shown in Figure 10, by simultaneously operating the luffing lever 43 forward and the slewing lever 42 to the left, the boom 30 is luffed and slewing in a counterclockwise direction (see position of point S). At this time, if the luffing operation amount is 100% and the slewing operation amount is 20% or less, a margin area M (min) with a width of 20% (minimum width) is set. As a result, the margin area M is maintained at its minimum width, allowing the boom 30 to be luffed and slewing in a direction that approaches structures, etc. (counterclockwise), and the boom 30 and work platform 40 to be moved further to the left.

[0062] Then, as shown in Figure 11, by continuing to operate the luffing lever 43 forward and the slewing lever 42 to the left simultaneously, the boom 30 is luffed and slewing while being slewing counterclockwise (see position of point T), and the boom 30 can be moved to a predetermined height position (a height position where the boom will not enter the interference prevention area A (AL,AR) even when slewing 360 degrees). Once the boom 30 reaches the predetermined height position, the boom 30 can be slewing to the desired slewing angle, and the work platform 40 can be moved to the position of the work object by luffing, extending, and slewing of the boom 30. Therefore, in conventional technology, the boom 30 was raised from its stowed position (moved almost straight up) and then rotated after reaching a predetermined height (a height that allows for full rotation). However, in this embodiment, the boom 30 can be rotated before reaching the predetermined height (a height that allows for full rotation), gradually moving towards the work object (moving towards the interference prevention area A). As a result, the work platform 40 can be moved efficiently toward the work object, improving work efficiency without compromising safety.

[0063] In the explanation of Figures 7 to 11 above, an example was given in which a maximum margin area M (max) and a minimum margin area M (min) are set to make the content of the invention easier to understand. However, the invention is not limited to this, and a margin area M of any width between 20% and 100% can be set depending on the amount of luffing and slewing operations.

[0064] As described above, with the interference prevention device of this embodiment, by varying the interference prevention area A provided around the vehicle's structure, etc., according to the amount of operation of the operating levers 42 and 43, the range of motion (the range in which the boom 30 can be swung) of the boom 30 can be secured without imposing excessive restrictions on the operation of the boom 30. Therefore, the boom 30 can be moved in the desired direction while preventing interference with the vehicle's structure, etc. (the work platform 40 can be efficiently brought closer to the desired position), making it possible to improve work efficiency while ensuring work safety.

[0065] Furthermore, according to the interference prevention device of this embodiment, by setting the interference prevention area A as an area with a margin area M added to the interference area B, and by varying the margin area M, which is an additional area, according to the amount of operation of the operating levers 42 and 43, it is possible to prevent the setting (variable setting) of the interference prevention area A from becoming complicated, and it is possible to achieve both work safety and work efficiency without requiring complex interference control.

[0066] Furthermore, according to the interference prevention device of this embodiment, when the boom 30 is being rotated in a predetermined direction while the slewing operation lever 42 and the luffing operation lever 43 are operated simultaneously, if it is determined that the boom 30 has reached the interference prevention area A, the rotation operation in the predetermined direction is restricted while the luffing operation is permitted. This makes it possible to maximize the range of motion (range in which the boom 30 can rotate) of the boom 30 and bring the work platform 40 closer to the work object, thereby improving the usability of the aerial work platform 1.

[0067] Furthermore, according to the interference prevention device of this embodiment, by setting the margin area M to be smaller as the amount of operation of the slewing operation lever 42 (slewing operation amount) decreases, for example, even when the elevation angle of the boom 30 is low (near and above the storage position), the boom 30 can be brought closer to the interference area B side (vehicle structure side, etc.) by keeping the slewing speed of the boom 30 low, thereby substantially expanding the range of motion (range in which the boom 30 can be slewing) and further improving work efficiency. On the other hand, by setting the margin area M to be larger as the amount of operation of the slewing operation lever 42 (slewing operation amount) increases, for example, when the boom 30 is slewing at high speed in a state where the elevation angle of the boom 30 is low (near and above the storage position), interference with structures, etc. can be reliably prevented, thereby improving work safety.

[0068] Furthermore, according to the interference prevention device of this embodiment, by setting the margin area M to decrease as the amount of operation of the luffing operation lever 43 (amount of luffing operation) increases, when the boom 30 is being luffed, the more the luffing speed is increased, the more the boom 30 is simultaneously rotated to move closer to the interference area B side (vehicle structure side, etc.). This substantially expands the range of motion (range in which it can rotate) of the boom 30, making it possible to efficiently bring the work platform 40 closer to the work object.

[0069] The present invention is not limited to the embodiments described above, and can be appropriately improved without departing from the spirit of the invention.

[0070] In the above embodiment, when luffing and slewing operations are performed simultaneously, the width of the margin area M (candidate margin area) calculated according to the amount of slewing operation is compared with the width of the margin area M (candidate margin area) calculated according to the amount of luffing operation, and the larger margin area M is selected. However, the system is not limited to this configuration, and the smaller margin area M may also be selected. When a larger margin area M is selected, safety is prioritized, while when a smaller margin area M is selected, work efficiency is prioritized. Furthermore, when luffing and slewing operations are performed simultaneously, the margin area M (candidate margin area) calculated according to the amount of slewing operation may be prioritized over the margin area M (candidate margin area) calculated according to the amount of luffing operation, and the margin area M calculated according to the amount of slewing operation may always be selected. Conversely, if luffing and turning operations are performed simultaneously, the margin region M calculated according to the luffing operation amount (candidate margin region) may be prioritized over the margin region M calculated according to the turning operation amount (candidate margin region), and the margin region M calculated according to the luffing operation amount may always be selected.

[0071] In the above embodiment, examples of structures on the vehicle body 2 include the third boarding step 63, the second handrail 65, the third handrail 66, and an antenna (not shown). However, the embodiment is not limited to these, and other structures such as a toolbox provided on at least one of the left and right sides of the mounting area of ​​the vehicle body 2 for storing work tools and equipment may also be used.

[0072] In the above embodiment, the margin area M was varied according to the amount of luffing and slewing operations. However, the configuration is not limited to this, and the margin area M may also be varied by taking into account the amounts of luffing and extending operations in addition to these operations.

[0073] In the above embodiment, a PTO-driven aerial work platform in which the power of the engine E is taken out by a power take-off mechanism PTO to drive the hydraulic pump 52 was illustrated, but the invention is not limited thereto, and an electric-driven (battery-driven) aerial work platform or a hybrid aerial work platform equipped with both and selectively switching the power source may also be used. Furthermore, in the above embodiment, a front-retractable aerial work platform in which the boom 30 is folded down and stored on the front side of the vehicle body 2 was illustrated, but the invention is not limited thereto, and a rear-retractable aerial work platform in which the boom 30 is folded down and stored on the rear side of the vehicle body 2 may also be used. [Explanation of Symbols]

[0074] 1. Aerial work platform 2 car bodies 7. Driver's Cabin 20 Turntables 30 Boom 39 Boom Rest 40 workbenches 41 Upper operating device (boom operating device) 42. Swivel operation lever (boom swivel operation unit) 43. Luffing lever (boom luffing control unit) 63. Third boarding / alighting step (structure) 65. Second handrail (structure) 66. Third handrail (structure) 91 Boom rotation angle detector (position detection unit) 92 Boom elevation angle detector (position detection unit) 93 Boom extension / retraction amount detector (position detection unit) 100 controllers 101 Position calculation unit (position detection unit) 102 Operation Control Unit 103 Area setting unit 104 Regulatory Department A Interference prevention area B Interference area M Margin Area

Claims

1. A vehicle body that can be driven, A boom is provided on the vehicle body and is configured to be able to raise and lower and rotate, and its tip is stored in a predetermined storage position on the vehicle body with the front or rear of the vehicle body facing forward or backward, A boom operating device for operating the boom, A position detection unit for detecting the position of the boom, An operation control unit that operates the boom in response to the operation of the boom operating device, A region setting unit for setting an interference prevention region to prevent the boom from interfering with the vehicle body and structures provided on the vehicle body, The system includes a position detection unit that determines whether the position of the boom detected by the position detection unit has reached the interference prevention area set by the area setting unit, and a restricting unit that restricts the operation of the boom if it is determined that the position of the boom has reached the interference prevention area. The interference prevention device for an aerial work platform is characterized in that the area setting unit varies the interference prevention area according to the amount of operation of the boom operating device.

2. The interference prevention region comprises an interference region which corresponds to the vehicle body and the structure, and a margin region which is set around the interference region. The interference prevention device for an aerial work platform according to claim 1, characterized in that the area setting unit varies the margin area according to the amount of operation of the boom operating device.

3. The boom operating device has a boom rotation operating unit for operating the boom in a slewing motion, and a boom luffing operating unit for operating the boom in a luffing motion. The interference prevention device for an aerial work platform according to claim 2, characterized in that when the regulating unit determines that the boom has reached the interference prevention area while the boom is being rotated in a predetermined direction while the boom is being raised and lowered by operating the boom rotation operation unit and the boom luffing operation unit, the regulating unit restricts the rotation operation in the predetermined direction while allowing the raising and lowering operation.

4. The interference prevention device for an aerial work platform according to claim 3, characterized in that when the boom is rotating due to the operation of the boom rotation operation unit, the margin area is set to be smaller the smaller the amount of operation of the boom rotation operation unit is.

5. The interference prevention device for an aerial work platform according to claim 3 or 4, characterized in that when the boom is raised or lowered by operating the boom luffing operation unit, the margin area is set smaller as the amount of operation of the boom luffing operation unit increases.

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