JP2002167198A - High lift work carriage - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a high lift work carriage with good operability capable of securing safety of a worker working at high elevations and manufacturing at a low cost. SOLUTION: This high lift work carriage is provided with an acceleration lever regulating mechanism 16. By means of the acceleration lever regulating mechanism 16, an acceleration lever 11 is forcibly switched to a low-speed side so that a traveling speed of a working carriage body 1 is set to a fixed speed or less when the height position of a worker boarding part 8 reaches a predetermined height, and the acceleration lever 11 is regulated to be kept in a low-speed state even if the worker boarding part 8 is lifted higher.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a worker's riding section mounted on a tip end of a boom rotatably provided on a self-propelled work carriage, and the worker's riding section can be moved up and down while maintaining a horizontal position. It relates to an aerial work platform.

[0002]

2. Description of the Related Art Harvesting in orchards such as apples, thighs, and tangerines requires harvesting at relatively high altitudes. A traveling aerial work platform is used. This aerial work platform is connected to a truck body equipped with a crawler-type traveling device, a diesel engine, and a hydraulic drive mechanism including a hydraulic pump, and is rotatably connected to a turning shaft provided upright on the truck body. Boom, an elevating cylinder provided in connection with the swivel axis and the boom, a swivel cylinder for swiveling the swivel axis and the boom, and attached to the end of the boom, to maintain a horizontal position even when the boom moves up and down. A worker mounting section (bucket) that can be moved up and down is provided.

[0003] The operator mounting section is provided with various operation sections such as a starter key, an accelerator lever, a lifting / swinging pedal, a traveling lever of left and right crawlers, and a seat on which the operator sits. In addition, a carrier can be attached to the worker mounting section.

When a worker performs a harvesting operation at a high place in an orchard, the operator rides on a worker mounting portion at a lowered position, turns a starter key to operate an engine, and then operates a lifting / lowering / swing pedal. Thus, the operator mounting portion is moved and arranged at a desired height position and direction by operating the elevating cylinder and the turning cylinder. In this state, when the harvesting operation is performed and the harvesting position is changed, the traveling device is operated by operating the left and right traveling levers, and the traveling device is moved forward or backward or turned to a position where the work is easy. At this time, the traveling speed of the traveling device can be moved at an arbitrary speed by changing the accelerator lever from a low speed to a high speed to increase the engine speed.

[0005] If the operator starts running with the accelerator at a high speed in a state in which the worker mounting part is at a high place, the work platform at a high place is not well balanced, and there are many irregular terrain and sloping lands and obstacles such as tree branches and leaves. In an orchard where there are many, there is a possibility that the safety of the worker may be impaired due to tilting of the boom or vibration of the worker mounting portion. It is also conceivable that the bogie may be run at a relatively high speed in a state where the worker mounting portion is at a high place due to a worker's operation error.

[0006] In recent years, due to an increase in interest in work safety, an aerial work platform that forcibly switches an accelerator lever to a low speed so that the traveling speed of the vehicle does not exceed a predetermined level when an operator mounting portion is at a predetermined height or higher has been developed. It has been developed and put into practical use. For example, Japanese Patent Application Laid-Open No. 63-94917 and
Japanese Patent Application Publication No. -6899 and the like have proposed an aerial work platform for controlling the vehicle speed.

[0007] The high work platform disclosed in Japanese Patent Application Laid-Open No. 63-94917 is provided with a speed control means for operating the carburetor to a lower speed side as the worker riding section is at a higher position.
This speed control means is provided with a pressing lever for pressing the throttle lever to the low speed side coaxially with the throttle lever, pulls a wire connecting the boom and the pressing lever with the rise of the worker riding section, and pulls the throttle lever. The friction lever is operated at a low speed side against the resistance of the friction plate. When the operator's boarding section descends, the wire is loosened so that the throttle lever is kept at a low speed. Also, JP-A-11-1168
Japanese Patent Application Publication No. 99-1992 discloses a lifting / lowering detecting means for detecting the lifting / lowering of a boom. Is switched to low speed.

[0008]

SUMMARY OF THE INVENTION Japanese Patent Application Laid-Open No. 63-9491
In the speed control means of the aerial work platform disclosed in Japanese Patent Application Publication No. 7 (1994), the pressing lever is screwed coaxially with the throttle lever together with the friction plate, and the pressing lever is pulled by a wire to resist the resistance of the friction plate. Due to the return to the low speed side, the pressing lever may not be able to return completely or the wire may be stretched due to excessive tension due to the frictional resistance of the friction plate and the tightening condition of the screw. There is a possibility that the switching to is insufficient. In addition, once the pressing lever is switched to the low speed side, since the worker's boarding section descends and remains as it is, the worker must return the pressing lever to the base against the resistance of the friction plate,
There was also a problem that the truck could not be driven at high speed by switching the throttle lever to a high speed side, resulting in poor operability. Further, the vehicle speed control device of the aerial work platform disclosed in Japanese Patent Application Laid-Open No. 11-116899 switches the hydraulic circuit sent from the hydraulic pump to the hydraulic motor in connection with the lifting / lowering detecting means for detecting the lifting / lowering of the boom. The number of parts is large, the configuration of the apparatus is complicated, and the manufacturing cost is high. Also, when the boom moves from the lowered position to the intermediate position and from the raised position to the intermediate position, the bogie always switches to high-speed running. It is difficult to say that the safe design is required because there is a case where crops are loaded in the passenger boarding section. Further, one end is connected to a throttle lever (accelerator lever) and the other end is connected to a cam groove. The other end of the wire is moved along a cam groove of a cam which rotates according to the vertical movement of the boom. However, there is also a problem that it is difficult to operate the throttle lever depending on the height position of the worker boarding section.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-mentioned problems of the prior art, and to provide a work platform at a high place which can ensure the safety of workers working at a high place, is easy to operate, and can be manufactured at low cost. It is in.

[0010]

To solve the above-mentioned problems, the present invention has the following arrangement. That is, a worker platform is attached to the end of a boom rotatably provided on a self-propelled platform, and the worker platform can be raised and lowered while maintaining a horizontal position. An accelerator lever provided in the riding section and capable of remotely controlling the traveling speed of the work carriage main body, and when the height position of the worker riding section reaches a predetermined height, the traveling speed of the work carriage main body falls below a certain speed. Forcefully switch the accelerator lever to the low speed side,
An accelerator lever adjusting mechanism for adjusting the accelerator lever so that the accelerator lever is maintained at a low speed even when the height position of the worker riding section further rises is provided.

[0011] The accelerator lever adjusting mechanism may include a switching lever that can be switched to a low speed side while being locked to the accelerator lever, and a connecting portion between the boom and the operator's mounting section, which is a rotation fulcrum. A link lever rotatably provided along with the vertical movement of the boom, and a connection wire for connecting the switching lever and the link lever, wherein a link-side connection portion of the connection wire extends in a longitudinal direction of the link lever. It is connected to the formed link groove, and is slidably connected from one groove end of the link groove to the other groove end position in accordance with the turning operation of the link lever. In addition, a link return spring that connects the operator's boarding section and the link lever is provided, and the link lever is pulled back by the link return spring and rotates while constantly hitting the link guide pin protruding from the boom It is characterized by doing. The switching lever is pulled by a return spring and is held at a reference position corresponding to the high-speed side of the accelerator lever. When the operator's boarding section rises from the lowered position to a predetermined height, the link lever is connected by rotating the link lever. When the wire is pulled and the switching lever moves to the opposite side from the reference position against the pulling force of the return spring, the switching lever is locked to the accelerator lever and switched to the low speed side as it is. In addition, the link side connecting portion of the connecting wire is located at one end side of the link groove when the worker riding portion is in the lowered position, and when the worker riding portion rises to a predetermined height, the connecting wire is rotated with the rotation of the link lever. The link side connecting part slides to the other end position of the link groove and pulls the connecting wire even if the worker's boarding section further rises and the link lever further rotates, while pulling It is characterized by missing power.

[0012]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIGS. 1, 2 and 3 are explanatory views of the operation of the accelerator lever adjusting mechanism when the operator's boarding section is at a lowered position, a predetermined height position, and a maximum raised position, and FIG. 4 is a side view of the aerial work platform. FIG. 5 is a top view of the aerial work platform.

First, a schematic structure of the aerial work platform will be described with reference to FIGS. 4 and 5. FIG. Reference numeral 1 denotes a work cart main body, which includes a pair of left and right crawler traveling devices 2, an engine 3, and a hydraulic drive mechanism (not shown) including a hydraulic pump and a hydraulic motor. The driving sprocket 4 of the traveling device 2 is driven to rotate by a hydraulic motor. Reference numeral 5 denotes a boom, one end of which is connected to a turning frame 6 provided upright on the work carriage main body 1 so as to be rotatable around a horizontal axis 7. Reference numeral 8 denotes a worker mounting portion (bucket), which is connected to the other end of the boom 5. The worker mounting unit 8 is configured to move up and down while maintaining a horizontal position even when the boom 5 moves up and down. Reference numeral 9 denotes a lifting cylinder, which includes a boom 5 and a revolving frame 6.
It is provided in connection with. The lifting cylinder 9 is expanded and contracted by hydraulic drive, and rotates the boom 5 about the horizontal axis 7 to raise and lower the worker mounting unit 8. The turning frame 6 is turned around a turning axis by a turning cylinder (not shown). The body cover 25 of the work cart body 1 is provided with a loading plate 26 on which crops can be loaded.

The worker mounting portion 8 is provided with a starter key 10 for starting the engine 3, an accelerator lever 11 for remotely controlling the traveling speed of the work vehicle, a lifting cylinder 9 and a turning cylinder. There are provided various operation units such as a lifting / swing pedal 12 for raising / lowering and turning, running levers 13 and 14 for controlling operation of left and right crawlers, and a seat 15 on which an operator sits. The lifting / swing pedal 12 is raised or lowered when, for example, stepping on the front side or the rear side,
When you step on the left or right side, it turns left and right, and it is diagonal (45 degrees)
When stepping on, an operation combining vertical movement and turning movement is performed. The traveling levers 13 and 14 control the operation of the left and right crawlers, and are configured to move forward and backward, and turn left and right. Commands from various operation units are transmitted from the operator mounting unit 8 to the bogie main body 1 through various cables wired in the frame of the boom 5. The front frame 8a of the worker mounting portion 8 is openable and closable, and when in the lowered position, the worker can open and close the front frame 8a from the ground to get on and off. Further, it is also possible to attach the carrier 8b to the worker mounting section 8.

An aerial work platform is provided with an accelerator lever adjustment mechanism 16. The accelerator lever adjusting mechanism 16 forcibly moves the accelerator lever 11 to the low speed side so that the traveling speed of the work carriage main body 1 becomes lower than a certain speed when the height position of the worker riding section 8 reaches a predetermined height. Switching is performed so that the accelerator lever 11 is maintained at a low speed even if the height position of the worker boarding section 8 further rises.

Hereinafter, the structure of the accelerator lever adjusting mechanism 16 will be specifically described with reference to FIGS. 17
Is a switching lever, which is mounted on the frame of the worker boarding section 8;
It is provided rotatably separately from the accelerator lever 11. The switching lever 17 has an L-shape, and rotates as the worker's boarding section 8 rises to switch to a low speed side while being locked to the accelerator lever 11 as described later. Reference numeral 18 denotes a link lever, which is provided so as to be rotatable about a fulcrum shaft 19 provided at a connecting portion between the boom 5 and the worker mounting section 8. The link lever 18 has a link groove 20 formed in the longitudinal direction.

Reference numeral 21 denotes a connecting wire, and the switching lever 1
7 and the link lever 18 are connected. The link-side connecting portion 21a of the connecting wire 21 is connected to the link groove 20 of the link lever 18, and moves from one groove end position 20a of the link groove 20 to the groove intermediate position 20b in accordance with the turning operation of the link lever 18. It is slidably connected to the other groove end position 20c. The switching-side connecting portion 21 b of the connecting wire 21 is connected to the switching lever 17.

Reference numeral 22 denotes a link return spring, one end of which is connected to the worker boarding section 8 and the other end of which is connected to the link lever 18. A link guide pin 23 is protrudingly provided near the connection side of the boom 5 with the worker boarding section 8. The link return spring 22 is pulled so as to return to the link guide pin 23 side so that the posture of the link lever 18 does not escape downward due to its own weight as the boom 5 rotates upward. Therefore, link lever 1
Numeral 8 is configured to rotate while being constantly pressed against the link guide pin 23 by the link return spring 22.

Reference numeral 24 denotes a return spring,
One end is connected to the switching lever 17 and the other end is the operator boarding section 8.
Connected to the frame. The switching lever 17 is pulled by the return spring 24 so as to be at the reference position P corresponding to the high speed side of the accelerator lever 11 when the worker riding section 8 is at the lowered position (see FIG. 1). When the worker riding section 8 rises from the lowering position A to the predetermined height position B, the connection wire 21 connected in the link groove 20 is pulled by the rotation of the link lever 18, and the switching lever 17 is moved.
Moves from the reference position P to the opposite position Q against the pulling force of the return spring 24. At this time, the switching lever 1
The switch 7 is switched to the low speed side while being locked to the accelerator lever 11 (see FIG. 2).

Next, the operation of the accelerator lever adjusting mechanism 16 will be described together with the raising and lowering operation of the worker mounting section 8.
First, as shown in FIG.
Then, the operator gets in and turns the starter key 10 to start the engine 3. The operator operates the traveling levers 13 and 14
Is operated to drive the traveling device 2 so that the work carriage main body 1 can travel. To increase the running speed,
By rotating the accelerator lever 11 from the low-speed side to the high-speed side to increase the rotation speed of the engine 3, it is possible to run at a higher speed.

In FIG. 1, when the worker mounting portion 8 is at the lowered position A, the switching lever 17 is pulled by the return spring 24 and is held at the reference position P side. Further, the connecting wire 21 connected to the switching lever 17 at the switching side connecting portion 21b is also pulled in the same direction, and the link side connecting portion 21a is locked at the groove end position 20a of the link groove 20 of the link lever 18. Further, the link lever 18 is pulled by a link return spring 22 and abuts against a link guide pin 23 in a state where the link lever 18 is inclined obliquely left and upward.

The operator operates the elevating / swinging pedal 12 while the vehicle is running or while the vehicle is stopped, and
Is rotated upward to raise the worker mounting section 8 to a predetermined height position B (about 2 m) shown in FIG. At this time, the link lever 18 rotates counterclockwise in FIG. 2 around the fulcrum shaft 19 while being abutted against the link guide pin 23 by the link return spring 22. In addition, link groove 2
The connection wire 21 connected to the link 0 is pulled in the same direction by the rotation of the link lever 18. As a result, the switching lever 17 connected at the switching-side connecting portion 21b is rotated from the reference position P to the opposite position Q. Therefore, when the accelerator lever 11 is on the high-speed side, the low-speed Switch to. In this embodiment, the speed is switched to a low speed by switching the accelerator lever 11 so that the traveling speed of the work vehicle main body 1 becomes 1 km / h or less. Further, when the worker mounting section 8 is raised to the predetermined height position B, the link lever 1 is moved.
8 is oriented horizontally, the wire link-side connecting portion 21a locked in the link groove 20 slides to the groove intermediate position 20b by the pulling force acting on the connecting wire 21. In this state, since the switching lever 17 has been moved to the opposite position Q, the accelerator lever 11 is surely switched to the low speed side.

When the operator operates the lifting / swing pedal 12 to raise the worker mounting portion 8 to the maximum ascending position C (about 3 m) shown in FIG. 3, the link lever 18 is rotated with the rotation of the boom 5. Is further rotated in the counterclockwise direction in FIG. 3 to pull the connecting wire 21. However, since the posture of the link lever 18 is directed obliquely downward and to the left, the link side connecting portion 21a connected to the link groove 20 slides from the groove intermediate position 20b in FIG. 2 to the groove end position 20c. As a result, the worker boarding section 8 further rises and the link lever 18
Even if is further rotated, the tension is released so as not to pull the connection wire 21 further. Therefore, even if the worker mounting section 8 moves up to the highest ascending position C, it is possible to prevent the connection wire 21 from being applied with excessive tension,
Moreover, since the switching lever 17 is kept at the opposite position Q, the accelerator lever 11 is kept being switched to the low speed side (see FIG. 3).

When the worker operates the lifting / swinging pedal 12 to lower the worker mounting portion 8 from the maximum rising position C shown in FIG. 3 to a predetermined height position B shown in FIG.
As a result, the link lever 18 rotates clockwise about the fulcrum shaft 19. At this time, link lever 1
8, the link side connecting portion 21a connected to the link groove 20 of the connecting wire 21 moves from the groove end position 20c to the groove intermediate position 20b.

When the worker mounting portion 8 is lowered from a predetermined height position B shown in FIG. 2 to a lowered position A shown in FIG. 1, the link lever 18 moves the fulcrum shaft 19 with the rotation of the boom 5. Rotate further clockwise around the center. At this time, since the attitude of the link lever 18 changes from the horizontal direction to the upper left, the link side connecting portion 21a connected to the link groove 20 of the connecting wire 21 moves from the groove intermediate position 20b in FIG. 2 to the groove end position 20a. . In addition, the connecting wire 21
Is the return of the link lever 18 and the return spring 2
The switching lever 17 rotates from the opposite position Q to the reference position P by the pulling force of 4, and returns. Therefore, when the worker mounting portion 8 is lowered from the predetermined height position B, the switching lever 1
7 starts to return to the reference position P side, the operator can switch the accelerator lever 11 to the high speed side to gradually increase the traveling speed.

According to the above configuration, since the accelerator lever adjusting mechanism 16 including the link lever 18, the switching lever 17, and the connecting wire 21 for connecting the link lever 18, the switching lever 17, and the like is provided on the aerial work platform, When the height position rises from the lowering position A to the predetermined height position B, the switching lever 17 moves the accelerator lever 11 by the switching lever 17 so that the traveling speed of the work carriage main body 1 becomes equal to or lower than a certain speed in accordance with the rotation of the link lever 18. The accelerator lever 11 is maintained at a low speed even if the operator is forced to switch to the low speed side and the height position of the worker boarding section 8 further rises to the maximum ascending position C. The safety and reliability can be improved without the risk of erroneous operation of switching to the high-speed side. The accelerator lever adjustment mechanism 16 is manufactured at low cost because of its simple structure. Come, maintenance can be easily performed.
Further, the switching lever 17 is configured to gradually return to the reference position P when the operator's boarding section 8 descends from the predetermined height position B, so that the operability is good, and the switching of the accelerator lever 11 to the rapid high speed side is performed. Operation safety is high because operation can be suppressed.

Although the preferred embodiment of the present invention has been described above, the present invention is not limited to the above-described embodiment, and the shape and the shape of the link lever 18 and the link groove 20 of the accelerator lever adjusting mechanism 16 are not limited. Length, accelerator lever 11
Of course, many modifications can be made without departing from the spirit of the invention, such as the height position of the worker boarding section 8 that adjusts the vehicle speed to the low speed side and the traveling speed of the work vehicle body 1 can be set arbitrarily. .

[0028]

As described above, the aerial work platform according to the present invention uses the accelerator lever adjusting mechanism to perform work when the height position of the worker's boarding section rises from the lowered position to the predetermined height position. The accelerator lever is forcibly switched to the low speed side so that the traveling speed of the bogie main body becomes equal to or lower than the predetermined speed, and the accelerator lever is maintained at the low speed state even if the height position of the operator's boarding section further rises. There is no risk of erroneous operation of switching the accelerator lever to the high-speed side in a place work, and safety and reliability can be improved. Since the structure of the accelerator lever adjustment mechanism is simple, it can be manufactured at low cost and maintenance can be easily performed. In addition, when the operator's riding section descends from the predetermined height position, the accelerator lever can be gradually switched to the high-speed side, so that the operation safety is high.

[Brief description of the drawings]

FIG. 1 is an explanatory diagram of an operation of an accelerator lever adjustment mechanism when an operator riding section is at a lowered position.

FIG. 2 is an operation explanatory view of an accelerator lever adjusting mechanism when an operator's boarding section is at a predetermined height position.

FIG. 3 is an explanatory diagram of an operation of an accelerator lever adjusting mechanism when an operator riding section is at a highest position.

FIG. 4 is a side view of the aerial work platform;

FIG. 5 is a top view of the aerial work platform;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Work body 2 Traveling device 3 Engine 4 Driving sprocket 5 Boom 6 Revolving frame 7 Horizontal axis 8 Worker mounting part 9 Lifting cylinder 10 Starter key 11 Accelerator lever 12 Lifting / swing pedal 13, 14 Traveling lever 15 Seat 16 Accelerator lever adjustment Mechanism 17 switching lever 18 link lever 19 fulcrum shaft 20 link groove 21 connecting wire 21a link side connecting part 21b switching side connecting part 22 link return spring 23 link guide pin 24 return spring 25 body cover 26 loading plate

Continued on the front page F term (reference) 2B041 AA07 AA13 AB05 AC11 BB03 BB05 BB14 BB15 2B075 JA01 JA03 JA19 2B076 AA07 DA02 DC01 DD04 EA01 EA09 EB05 EC23 ED01 3F333 AA12 AA15 AB01 AC01 BB03 BB10 FA02 CA21 FA

Claims (5)

[Claims] 1. An operator riding section is attached to a tip end of a boom rotatably provided on a self-propelled work carriage body,
An aerial work platform in which the worker boarding section can be moved up and down while maintaining a horizontal position, an accelerator lever provided on the worker boarding section and capable of remotely controlling a traveling speed of the work carriage body, When the height position reaches a predetermined height, the accelerator lever is forcibly switched to a low speed side so that the traveling speed of the work carriage main body becomes equal to or lower than a certain speed, and the height position of the worker riding section further rises An aerial work platform comprising an accelerator lever adjusting mechanism for adjusting the accelerator lever so as to be maintained at a low speed. 2. An accelerator lever adjusting mechanism, comprising: a switching lever capable of switching to a low speed side while being locked to the accelerator lever; A link lever rotatably provided along with the movement; and a connecting wire connecting the switching lever and the link lever, wherein a link-side connecting portion of the connecting wire extends in a longitudinal direction of the link lever. 2. The link groove is connected to the formed link groove, and is slidably connected from one groove end of the link groove to the other groove end position in accordance with a rotation operation of the link lever. Work trolley. 3. A link return spring for connecting the worker riding section and the link lever is provided, and the link lever is pulled back by the link return spring to a link guide pin protruding from the boom. 3. The aerial work platform according to claim 2, wherein the aerial work platform is constantly abutted and rotates. 4. The switching lever is pulled by a return spring and held at a reference position corresponding to a high-speed side of the accelerator lever, and when the worker riding section rises from a lowered position to a predetermined height, the switching lever is turned on. When the link wire is pulled by the rotation of the link lever and the switching lever moves to the opposite side from the reference position against the pulling force of the return spring, it is locked to the accelerator lever and moves toward the low speed side as it is. 3. The aerial work platform according to claim 2, wherein switching is performed. 5. The link side connecting portion of the connecting wire is located at one end side of a link groove when the worker riding portion is in a lowered position, and when the worker riding portion rises to a predetermined height, the link lever is turned off. Even if the worker's boarding portion further rises and the link lever further rotates, the link-side connecting portion remains at the other position of the link groove while sliding to the intermediate position of the link groove while pulling the connecting wire with the rotation. The aerial work platform according to claim 2, wherein the work is slid to an end position to release the pulling force of the connecting wire.