JP2022134767A - Mounting structure of work platform for aerial work vehicle - Google Patents

Abstract

[PROBLEMS] To reduce the number of parts and man-hours for assembly work for restricting the rise of a workbench with respect to the boom side, and to compactly integrate a structure and a parallel link mechanism for restricting the rise of the workbench with respect to the boom side. To provide a mounting structure of a workbench in an aerial work vehicle capable of A parallel link mechanism (70) composed of a jib fixing member (71), an upper link member (80a), a workbench fixing member (51), and a lower link member (80b) is provided, and the parallel link mechanism (70) connects the jib fixing member (71). A stopper member 83 is provided on at least one of the upper link member 80a and the lower link member 80b, and the jib fixing member 71 is brought into contact with the stopper members 83a and 83b to move the work table upward. are provided with regulating portions 74a and 74b for regulating the movement of the [Selection drawing] Fig. 3

Description

TECHNICAL FIELD The present invention relates to a mounting structure for a work platform in a vehicle for high lift work, in which a boom is provided on a vehicle body so that it can be raised and lowered, and a parallel link mechanism supports the work platform at the tip of the boom so that the work platform can swing vertically.

In general, an aerial work vehicle has a traveling body having wheels or a crawler device, a swivel base provided on the traveling body so as to be able to turn horizontally, and a swivel base provided so as to be able to undulate and extend and contract. and a workbench supported swingably at the tip of the boom. In addition, an operation device is provided on the workbench, and a worker on the workbench operates the operation device to control the swivel operation of the swivel base, the boom raising and lowering operation, and the swinging operation of the workbench. there is

When working on a work target located at a high place using the aerial work vehicle as described above, the worker gets on the work table with tools and materials, etc., and operates the operation device provided on the work table. By being operated by the worker, the workbench can be moved to an elevated work target. At this time, a moment (hereinafter referred to as "overturning moment") always acts on the aerial work platform to overturn the vehicle body toward the workbench. Since the overturning moment increases due to an increase in the load on the workbench and the extension of the boom, etc., the aerial work platform detects the load on the workbench and adjusts the boom according to the detected load. Some booms are designed to limit the range of motion so that the overturning moment, which varies as the boom is operated, does not impair the stability of the vehicle body.

For example, in the aerial work vehicle disclosed in Patent Document 1, a parallel link mechanism is formed between the boom side and the platform side by connecting the boom side and the workbench (working platform) side with an upper bearing link and a lower bearing link. form and allow movement relative to each other. A load member (carriage bolt) is provided on the first stop plate fixed to the workbench side, and by engaging this load member with a load cell fixed to the boom side, the load on the workbench side is detected. ing. This separates the workbench side load and the load moment so that only the total weight of the workbench side load can be applied to the load cell.

Japanese Patent No. 6668502

In the aerial work vehicle of Patent Document 1, a second stop plate is provided at a position higher than the first stop plate with respect to the boom side between the upper bearing link and the lower bearing link. On the other hand, when the workbench attempts to rise above the predetermined level, the first stop plate comes into contact with the second stop plate, thereby restricting the workbench from rising above the predetermined level. This prevents the electronic circuit to which the load cell sensing signal is input from losing calibration due to an upward force on the worktable. However, since the first stop plate and the second stop plate are composed of members different from the parallel link mechanism, the number of parts increases when restricting the upward movement of the workbench using such a structure. , there was a problem that the man-hours of the assembly work increased.

SUMMARY OF THE INVENTION The present invention has been made in view of such problems, and is intended to reduce the number of parts for restricting the rise of a workbench with respect to the boom side, reduce the number of man-hours for assembly work, and reduce the workbench's height relative to the boom side. An object of the present invention is to provide a mounting structure for a workbench in a vehicle for work at height, capable of compactly combining a structure for restricting an ascent and a parallel link mechanism.

In order to solve the above-mentioned problems, the mounting structure of a work platform for a vehicle for high-elevation work according to the present invention is a vehicle for high-elevation work constructed by attaching a work platform to the tip of a boom provided on a vehicle body so as to be able to rise and fall. A mounting structure of the workbench to the tip of the boom, comprising: a boom-side vertical member (for example, jib fixing members 71 and 71' in the embodiment) pivotally connected to the tip of the boom and extending in the vertical direction; An upper horizontal link member (for example, upper link members 80a and 80a' in the embodiment) whose proximal end side is pivotally connected to the boom-side vertical member and extends horizontally; a workbench-side vertical member (for example, workbench fixing members 51 and 51′ in the embodiment) to which the workbench is fixed, and a horizontally extending member located below the upper horizontal link member, and a lower horizontal link member (for example, the lower link members 80b and 80b' in the embodiment) whose base end side is pivotally connected to the boom side vertical member and whose tip side is pivotally connected to the workbench side vertical member. A parallel link mechanism (for example, parallel link mechanisms 70 and 70′ in the embodiment) is provided, and the work table can be moved up and down with respect to the boom-side vertical member by the parallel link mechanism, and the upper horizontal link member or the At least one of the lower horizontal link members is provided with an abutment member (for example, stopper members 83 and 83' in the embodiment), and a restricting portion ( For example, the restriction portions 74, 74') in the embodiment are provided on the boom-side vertical member.

Further, in the mounting structure of the workbench for the aerial work vehicle configured as described above, the restricting portion is provided at a position that contacts the contact member when the upper horizontal link member and the lower horizontal link member are substantially horizontal. preferably.

In addition, the mounting structure of the work platform in the aerial work vehicle configured as described above includes a load detector (for example, the load cell 90 in the embodiment) for detecting the load of the work platform, and the load detector It is positioned above the horizontal link member and attached to a mounting portion (for example, the load cell mounting portion 72 in the embodiment) provided on the boom side vertical member, and the workbench side vertical member moves up and down by the parallel link mechanism. A load applying member (for example, the It preferably has a pressure bolt 53).

Furthermore, in the mounting structure of the workbench for the aerial work vehicle configured as described above, an additional load adjusting mechanism (for example, the pressing bolt 53, the upper nut 54a and the It has a lower nut 54b), and in a state in which the restricting portion and the contact member are in contact, the additional load adjusting mechanism reduces the gap and applies an additional load to the load detector. It is preferable to be able to

According to the mounting structure of the work platform in the aerial work vehicle according to the present invention, the parallel link mechanism is composed of the boom-side vertical member, the upper horizontal link member, the work platform-side vertical member, and the lower horizontal link member. At least one of the upper horizontal link member and the lower horizontal link member is provided with an abutment member, and the boom side vertical member is provided with a restriction portion that abuts against the abutment member to restrict upward movement of the work platform. there is In this way, by providing the abutting member on at least one of the upper horizontal link member or the lower horizontal link member and providing the regulating portion on the boom side vertical member, the number of parts for regulating the lifting of the workbench with respect to the boom side. can be reduced, and the man-hours for assembly work can be reduced. Further, since the abutting member is provided on at least one of the upper horizontal link member and the lower horizontal link member, the structure for restricting the worktable from rising with respect to the boom side and the parallel link mechanism can be compactly assembled.

In addition, the work platform mounting structure for the aerial work platform configured as described above preferably includes a load detector for detecting the load of the work platform, and the load detector is positioned above the upper horizontal link member. The load detector is attached to the mounting portion provided on the boom side vertical member, and the worktable side vertical member is attached to the mounting portion according to the downward movement of the worktable, which is made vertically movable by the parallel link mechanism. It has a load applying member that abuts on the vessel from above and applies a load from the workbench. By attaching the load detector to the outside (more specifically, above) of the parallel link mechanism in this way, the load detector is not interposed between the work table side and the boom side. By shortening the length of the horizontal link member in the longitudinal direction, the space between the workbench side and the boom side can be reduced, and the maintainability of the load detector can be improved.

Further, in the mounting structure of the workbench for the aerial work vehicle having the above configuration, it is preferable to have an additional load adjusting mechanism that adjusts the distance between the load applying member and the load detector, and the restricting portion and the abutment member are brought into contact with each other. In the contact state, an additional load adjusting mechanism reduces the distance between the load applying member and the load detector so that an additional load can be applied to the load detector. As a result, it is possible to prevent the workbench from rising due to vibration or the like when the aerial work platform is traveling, so that the load applying member can avoid applying an abnormal load to the load detector. can be done.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a side view showing the appearance of an aerial work platform equipped with a workbench mounting structure according to a first embodiment of the present invention; FIG. 3 is a side view showing the appearance of a jib mechanism and a workbench of the aerial work vehicle; FIG. 3 is a perspective view showing the appearance of a parallel link mechanism in the mounting structure of the workbench of the first embodiment according to the present invention; FIG. 4 is a perspective view showing the appearance of main members constituting a parallel link mechanism in the mounting structure for the workbench. FIG. 5 is an explanatory view for explaining the operation of the workbench fixing member in the mounting structure of the workbench. FIG. 7 is a perspective view showing the appearance of a parallel link mechanism in the mounting structure of the workbench of the second embodiment according to the present invention; FIG. 4 is a perspective view showing an appearance of a jib fixing member in the mounting structure for the workbench. It is a perspective view which shows the external appearance of the link member in the said mounting structure of a workbench. FIG. 5 is an explanatory view for explaining the operation of the workbench fixing member in the mounting structure of the workbench. FIG. 11 is a perspective view showing another form of the link member in the mounting structure for the workbench.

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 1 shows a self-propelled aerial work vehicle 1 as an example of the aerial work vehicle equipped with the work platform mounting structure according to the first embodiment of the present invention. The aerial work vehicle 1 includes a traveling body 10 configured to be able to travel, a revolving body 20 provided on the upper part of the traveling body 10 and capable of turning in a horizontal direction, and a revolving body 20 provided on the upper part of the revolving body 20 and capable of raising and lowering. It comprises a boom 30, a jib mechanism 40 provided at the tip of the boom 30, and a workbench 50. As shown in FIG. 1, the length of the boom 30 is partially omitted.

The traveling body 10 has a pair of left and right steering wheels 12 and a pair of left and right driving wheels 13 rotatably provided on a traveling body frame 11 . A turning mechanism 15 is provided at the center of the upper part of the traveling body frame 11, and the turning mechanism 15 is configured to be able to turn the turning body 20 in the horizontal direction. The revolving mechanism 15 supplies hydraulic oil to an outer ring fixed to the traveling body frame 11 , an inner ring fixed to the revolving body 20 engaged with the outer ring, and various actuators provided on the traveling body 10 . and a rotary center joint (not shown). A boom 30 is provided on the upper portion of the revolving body 20, and the boom 30 is vertically rotatable (raising and lowering) about a pivot pin 34 as an axis. The boom 30 has a base end boom 31 pivotally connected to the revolving body 20, and an intermediate boom 32 and a tip boom 33 telescopically combined with the base end boom 31, and these booms are configured to be telescopic. there is

A boom head 36 provided at the tip of the tip boom 33 is pivotally connected to a jib base 43, which is the base end of a parallel link type jib mechanism 40, by a pivot pin 43a. The jib base 43 is pivotally connected to a piston rod 37a of a boom-side leveling cylinder 37 (see FIG. 2) provided inside the tip boom 33 by a pivot pin 43b. By extending and retracting the boom-side leveling cylinder 37, the jib mechanism 40 can be raised and lowered with respect to the boom head 36 about the pivot pin 43a.

A vertical post 60 is attached to the jib head 45 that is the tip of the jib mechanism 40 , and the vertical post 60 supports the workbench 50 via a parallel link mechanism 70 . An oscillating motor is provided inside the vertical post 60, and the work table 50 can be oscillated by this oscillating motor. Further, the parallel link mechanism 70 allows the workbench 50 to move up and down with respect to the tip of the jib mechanism 40 while keeping the floor level. An operation device is provided on the workbench 50, and an operator on the workbench 50 operates the operation device to move the traveling body 10, swing the revolving body 20, raise and lower the boom 30, and It is possible to control the swing operation of the work table 50 and the like.

Next, referring to FIG. 2, the configuration of the jib mechanism 40 will be described. The jib mechanism 40 is mainly composed of a jib base 43 , an upper arm member 41 , a lower arm member 42 and a jib head 45 . The jib base 43 is pivotally connected to the tip end of the cylinder rod 37a of the boom head 36 and the leveling cylinder 37 by means of the aforementioned pivot pins 43a and 43b, and a long bar-like upper arm member 41 extending horizontally by means of a pivot pin 43c. It is pivotally connected to one end. The other end of the upper arm member 41 is pivotally connected to the jib head 45 by a pivot pin 45a. A long rod-shaped lower arm member 42 extending substantially parallel to the upper arm member 41 is provided below the upper arm member 41, and one end of the lower arm member 42 is connected to the jib base 43 by a pivot pin 43d. The other end of the lower arm member 42 is pivotally connected to the jib head 45 by a pivot pin 45b below the pivot pin 45a.

A jib side cylinder 44 having a piston rod 44a and a cylinder tube 44b is provided between the upper arm member 41 and the lower arm member 42 . A distal end portion of the piston rod 44a is pivotally connected to the jib base 43 and the lower arm member 42 by a pivot pin 43d at a pivotal connection portion between the jib base 43 and the lower arm member 42. As shown in FIG. The base end of the cylinder tube 44b of the jib side cylinder 44 is pivotally connected to the upper arm member 41 by a pivot pin 41a. With such a configuration, the boom-side leveling cylinder 37 is telescopically operated according to the hoisting operation of the boom 30 to control the leveling of the workbench 50, and the jib-side cylinder 44 is telescopically operated so that the floor of the workbench 50 is moved. The workbench 50 can be vertically swung with respect to the tip of the boom 30 while the surface is kept horizontal.

Next, referring to FIGS. 3 and 4, the configuration of the parallel link mechanism 70 and its surroundings will be described. Here, FIG. 3 is a perspective view showing the appearance of the parallel link mechanism 70 and its surroundings, and FIG. In FIGS. 3 and 4, when referring to each illustrated part without distinguishing between the upper part and the lower part, the words "upper part" or "lower part" are omitted from the name of each part, and " The letters a” and “b” are omitted.

As shown in FIG. 3, the parallel link mechanism 70 mainly includes a jib fixing member 71 for fixing the parallel link mechanism 70 to a vertical post 60 attached to a jib head 45, which is the tip of the jib mechanism 40, and an upper link. It is composed of a member 80a, a lower link member 80b, and a workbench fixing member 51 to which the workbench 50 is fixed. The jib fixing member 71 has a substantially U-shaped shape when viewed from the side, and the upper portion extending in the horizontal direction serves as a vertical post upper fixing portion 73a to which the upper portion of the vertical post 60 is fixed. The lower portion extending in the horizontal direction serves as a vertical post lower fixing portion 73b to which the lower portion of the vertical post 60 is fixed.

As shown in FIG. 4, the vertically extending portion of the jib fixing member 71 is provided with an upper pivot pin hole 75a and a lower pivot pin hole 75b below it. An upper restricting portion 74a projecting toward the workbench 50 is formed slightly above the upper pivot pin hole 75a. Similarly, a lower restricting portion 74b projecting toward the work table 50 is formed slightly above the lower pivot pin hole 75b. A load cell mounting portion 72 for mounting a load cell 90 for detecting the load on the workbench 50 side is provided above the upper pivot pin hole 75a.

The jib fixing member 71 and the workbench fixing member 51 are connected by an upper link member 80a and a lower link member 80b. Since the upper link member 80a and the lower link member 80b have the same shape, the shape of the link member 80 will be described without distinguishing between the upper link member 80a and the lower link member 80b in the following description.

The link member 80 is composed of a first link 84 and a second link 85 in the form of long flat plates extending in the horizontal direction, and a stopper member 83 in the shape of a pipe. The first link 84 and the second link 85 have the same shape, and one end is provided with a workbench pin hole 86 for penetrating the workbench side pivot pin 81 (see FIG. 3). The other end is provided with a jib-side pin hole 87 for passing the jib-side pivot pin 82 (see FIG. 3). A stopper member 83 connects the first link 84 and the second link 85 in a state of facing each other. Here, the position of the stopper member 83 is between the work table side pin hole 86 and the jib side pin hole 87 of the first link 84 and the second link 85, and the length of the stopper member 83 is the length of the first link. The distance between 84 and the second link 85 is at least wider than the width w1 of the jib fixing member 71 (see FIG. 3) and the width w2 of the workbench fixing member 51 (see FIG. 3).

With the above configuration, the position of the jib side pin hole 87a of the upper link member 80a is aligned with the position of the upper pivot pin hole 75a of the jib fixing member 71, and each pin hole is fitted with a jib side upper pivot pin 82a (see FIG. 3). to pivotally connect the jib fixing member 71 and the upper link member 80a. Similarly, the position of the jib side pin hole 87b of the lower link member 80b is aligned with the position of the lower pivot pin hole 75b of the jib fixing member 71, and the jib side lower pivot pin 82b (see FIG. 3) penetrates each pin hole. By doing so, the jib fixing member 71 and the lower link member 80b are pivotally connected. Although not shown in FIG. 4, the work table fixing member 51 is also provided with pivot pin holes similar to the upper pivot pin holes 75a and lower pivot pin holes 75b of the jib fixing member 71. there is Therefore, the positions of the pivot pin holes provided in these work table fixing members 51 are aligned with the positions of the work table side pin holes 86a and 86b of the upper link member 80a and the lower link member 80b. The work table fixing member 51 and the upper link member 80a and the lower link member 80b are pivotally connected by penetrating the work table side upper pivot pin 81a and the work table side lower pivot pin 81b (see FIG. 3).

As shown in FIG. 3, the formation position of the regulating portion 74 in the jib fixing member 71 is the position of the workbench side pivot pin 81 and the jib portion side pivot pin 81 when abutting on the corresponding stopper member 83. 82 are set so as to be substantially horizontal. Alternatively, only one of the upper restricting portion 74a and the lower restricting portion 74b may be formed. In this case, the stopper member 83 in the link member 80 corresponding to the omitted restricting portion can be omitted.

As shown in FIG. 3 , a load cell mounting portion 72 is provided at the top of the jib fixing member 71 , and a load cell 90 is fixed to the load cell mounting portion 72 . The workbench fixing member 51 is provided with a flat pressing bolt support portion 52 that protrudes toward the jib mechanism 40 from a position higher than the upper surface of the load cell 90 when the stopper member 83 and the restricting portion 74 are in contact with each other. It is A through hole (not shown) is provided in the pressing bolt support portion 52 at a position facing the upper surface of the load cell 90 . A bolt 53 is penetrated. When the tip of the pressing bolt 53 inserted into the through hole of the pressing bolt support portion 52 contacts the upper surface of the load cell 90 and the load on the work table 50 side is applied to the load cell 90, a detection signal corresponding to the added load is generated. is output from the load cell 90 to a controller (not shown). The controller regulates the operating range of boom 30 and the like based on the detection signal output from load cell 90 .

The depth of penetration of the pressing bolt 53 into the pressing bolt support portion 52 is determined by an upper nut 54a screwed onto the pressing bolt 53 from above with the pressing bolt support portion 52 interposed therebetween and a lower nut 54b screwed onto the pressing bolt 53 from below ( See FIG. 5). As the penetration of the pressing bolt 53 becomes deeper, the position of the work table 50 under no load (hereinafter also referred to as "initial position") shifts upward until the stopper member 83 and the restricting portion 74 come into contact with each other. become. In this embodiment, when the workbench 50 is in a no-load state, the pressing bolt 53 can be inserted until the stopper member 83 and the restricting portion 74 come into contact with each other. By further screwing the pressing bolt 53 toward the load cell 90 in this state, a load exceeding the load on the work table 50 side when no load is applied to the load cell 90 (for example, the load on the work table 50 side when no load is +30 ~50 kg) can be added. By forming a female thread in the through hole of the pressing bolt support portion 52 to be screwed with the pressing bolt 53, the lower nut 54b is omitted, and the penetration depth of the pressing bolt 53 can be adjusted only by the upper nut 54a. good too.

Next, with reference to FIG. 5, the operation of the parallel link mechanism 70 when a downward load is applied to the workbench 50 and when an upward load is applied will be described. 5 shows the side surface from the tip portion of the jib mechanism 40 to the base end portion of the workbench fixing member 51, and the illustration of the workbench 50 is omitted. Further, in FIG. 5, the same components as those shown in FIGS. 2 to 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. Further, in the example shown in FIG. 5, when the work table 50 side is not loaded, the stopper members 83a and 83b of the upper link member 80a and the lower link member 80b come into contact with the regulating portions 74a and 74b, respectively (at this time, the work table 50 side is in contact with the stopper members 83a and 83b). It is assumed that the penetration depth of the pressing bolt 53 is adjusted so that the position of the base-side pivot pin 81 and the position of the jib-side pivot pin 82 are substantially horizontal.

First, when a downward load is applied as shown by an arrow in FIG. The link members 80b tilt downward about the jib-side upper pivot pin 82a and the jib-side lower pivot pin 82b, respectively, and the workbench fixing member 51 moves downward. As a result, the pressing bolt 53 applies a load on the workbench 50 side to the load cell 90 , and the load cell 90 outputs a detection signal corresponding to the applied load.

On the other hand, when an upward load as shown by the arrow in FIG. Since the member 83 abuts on the upper restricting portion 74 a and the lower restricting portion 74 b formed on the jib fixing member 71 , the workbench fixing member 51 is restricted from rising.

According to the configuration described above, the load cell 90 is positioned outside the parallel link mechanism 70 (specifically, above the area surrounded by the jib fixing member 71, the upper link member 80a, the workbench fixing member 51, and the lower link member 80b). , maintenance of the load cell 90 is facilitated, and adjustment of the penetration depth of the pressing bolt 53 is facilitated. Further, since an additional load can be applied to the load cell 90 by the pressing bolt 53, the upper nut 54a, and the lower nut 54b, the work table 50 can move up and down due to vibrations that occur when the aerial work vehicle 1 travels, for example. As a result, it is possible to reduce the risk of damage to the load cell 90 due to the pressing bolt 53 bouncing on the upper surface of the load cell 90 and applying an abnormal load to the load cell 90 .

Further, when the workbench 50 side has no load, the depth of penetration of the pressing bolt 53 is adjusted so that the position of the workbench side pivot pin 81 and the position of the jib side pivot pin 82 are substantially horizontal. The inclination of the upper link member 82a and the lower link member 82b about the jib-side upper pivot pin 82a and the jib-side lower pivot pin 82b is displaced in the vicinity of the horizontal in accordance with the vertical movement of the workbench fixing member 51. become. As a result, the movement of the tip of the pressing bolt 53 on the upper surface of the load cell 90 is mainly in the vertical direction, and the movement in the horizontal direction (horizontal direction in FIG. 5A) is small. A decrease in the load component is suppressed. Therefore, it is possible to reduce the decrease in accuracy of the load detected by the load cell 90 .

Further, according to the above-described configuration, the load cell 90 is not subjected to a load other than the load on the workbench 50 side. None. For example, in the configuration described in the above-mentioned Patent Document 1, a large load is applied to the workbench from the bottom to the top, and the first stop plate provided with the load member (carriage bolt) is attached to the second stop plate. If the load member bends downward due to contact with the stop plate, the load member will apply a downward load to the load cell, and the load cell will output an abnormal detection result. There is no such thing in form.

Next, a mounting structure for a workbench according to a second embodiment of the present invention will be described with reference to FIGS. 6 to 10. FIG. FIG. 6 shows the configuration of the parallel link mechanism 70' and its surroundings in the mounting structure of the workbench of this embodiment. FIG. 7 shows the appearance of a jib fixing member 71' that constitutes the parallel link mechanism 70', and FIG. 8 shows the appearance of the link member 80' that constitutes the parallel link mechanism 70'. 6 to 8, the same components as those shown in FIGS. 3 and 4 are denoted by the same reference numerals, and detailed description thereof will be omitted. 3 and 4 are denoted by the same reference numerals with a "'" (dash) at the end. Moreover, since the upper link member 80a' and the lower link member 80b' shown in FIG. 6 have the same configuration, the link member 80' shown in FIG. shows a configuration common to both.

As shown in FIG. 6, the vertical portion of the workbench fixing member 51' in this embodiment is formed of a member having a U-shaped cross section in the horizontal direction, and the inner width w2' of the workbench fixing member 51' is wider than the width w1' of the jib fixing member 71'. The jib-side ends of the upper link member 80a' and the lower link member 80b' are pivotally connected by a jib-side upper pivot pin 82a and a jib-side lower pivot pin 82b so as to sandwich the jib fixing member 71' from the outside. Further, the work table side end portions of the upper link member 80a' and the lower link member 80b' are accommodated inside the work table fixing member 51' and connected to the work table side upper pivot pin 81a and the work table side lower pivot pin 81a. Connection pin 81b
It is pivotally connected by

The restricting portion 74' of the jib fixing member 71' in this embodiment is provided only slightly above the lower pivot pin hole 75b as shown in FIG. No restricting portion is provided slightly above the hole 75a. In addition, as shown in FIG. 8, the link member 80' of this embodiment is provided with openings 89 for mounting the bearings 90 on both ends of the first link 84' and the second link 85'. . Both ends of the workbench-side pivot pin 81 and the jib-side pivot pin 82 are fixed to the openings 89 of the first link 84' and the second link 85' via bearings 90, respectively. The stopper member 83' has a cylindrical shape, the inner diameter of which matches the diameter of the opening 89, and both ends thereof are attached to the workbench side pivot pins at the first link 84' and the second link 85'. It is fixed by welding or the like to the peripheral edge of the opening 89 on the side where 81 is fixed. Thus, the stopper member 83' also serves as a connecting member that connects the first link 84' and the second link 85'.

Note that the inner diameter of the stopper member 83 ′ may be larger than the diameter of the opening 89 . The outer diameter of the stopper member 83' is matched with the diameter of the opening 89, and both ends of the stopper member 86' are inserted into the opening 89 and fixed to the first link 84' and the second link 85'. You may make it In this case, it is necessary to match the outer diameter dimension of the bearing 90 with the inner diameter dimension of the stopper member 83'.

Next, referring to FIG. 9, the operation of the parallel link mechanism 70' when a downward load is applied to the workbench 50 and when an upward load is applied thereto will be described. 9 shows a side view from the tip of the jib mechanism 40 to the base of the work table fixing member 51' (however, the work table 50 is not shown), and the hatched portion indicates a cross section. ing. Further, in FIG. 9, the same components as those shown in FIGS. 6 to 8 are denoted by the same reference numerals, and detailed description thereof will be omitted. Furthermore, in the example shown in FIG. 9, when there is no load on the work table 50 side, the lower stopper member 83b' of the lower link member 80b' comes into contact with the restricting portion 74' (at this time, the work table side pivot pin 81 is It is assumed that the penetration depth of the pressing bolt 53 is adjusted so that the position and the position of the jib-side pivot pin 82 are substantially horizontal.

First, when a downward load is applied as indicated by an arrow in FIG. The lower link members 80b' tilt downward about the jib-side upper pivot pin 82a and the jib-side lower pivot pin 82b, respectively, and the workbench fixing member 51' moves downward. As a result, the pressing bolt 53 applies a load on the workbench 50 side to the load cell 90 , and the load cell 90 outputs a detection signal corresponding to the applied load.

On the other hand, when an upward load as indicated by the arrow in FIG. , the jib fixing member 71' is abutted against the restricting portion 74' formed on the jib fixing member 71', thereby restricting the workbench fixing member 51' from rising.

According to the mounting structure of the workbench of this embodiment, the stopper member 83' has a cylindrical shape, and the first link 84' and the second link 85' are arranged so as to accommodate the workbench-side pivot pin 81 inside thereof. fixed to Thereby, the length L (see FIG. 8) in the longitudinal direction of the first link 84' and the second link 85' is shorter than the length in the longitudinal direction of the first link 84 and the second link 85 in the first embodiment. can do.

In the second embodiment, considering the strength of the worktable side pivot pin 81 and the upward load that can be applied to the worktable 50 and the like, the worktable side pivotal connection pin 81 is attached to the jib fixing member 71'. If it can be determined that there is no problem even if the restricting portion 74' is brought into direct contact (for example, the workbench side pivot pin 81 is not damaged), the stopper member 83' is omitted as shown in FIG. 10(a). Alternatively, the workbench side pivot pin 81 may be brought into direct contact with the restricting portion 74'. In this case, a connecting member (having no function as a stopper member) that connects the first link 84' and the second link 85' may be provided separately.

As such a connecting member, for example, as shown in FIG. A shaped connecting member 91 may connect the first link 84 ″ and the second link 85 ″. Further, as shown in FIG. 10(c), in the longitudinal direction of the first link 84' and the second link 85', a first connecting member 92 having an L-shaped cross section is arranged at an intermediate position between the first link 84' and the second link 85'. A plate-shaped second connecting member 93 may be arranged below the first connecting member 92, and the first link 84' and the second link 85' may be connected by these connecting members.

Moreover, the present invention is not limited to the above-described embodiments and modifications, and can be improved as appropriate without departing from the gist of the present invention. For example, in the present embodiment, a self-propelled aerial work vehicle in which a worker controls the travel of the traveling object from an operation device provided on the workbench, but a swivel base is provided on the vehicle body of the cab-over type truck, It may be an aerial work vehicle in which a boom having a workbench at its tip is attached to a swivel base so that it can be raised and lowered. In addition, in the present embodiment, the traveling body is a tire-wheel type aerial work vehicle, but the traveling body is not necessarily limited to the tire-wheel type, and may be one that travels by a crawler device or the like. good.

1 aerial work vehicle 10 running body 20 rotating body 30 boom 40 jib mechanism 50 work table 51, 51' work table fixing member 52 pressing bolt support portion 53 pressing bolt 54a upper nut 54b lower nut 60 vertical post 70, 70' parallel link Mechanisms 71, 71' jib fixing member 74a upper restricting portion 74b lower restricting portion 74' restricting portions 80a, 80a' upper link members 80b, 80b' lower link members 83a, 83a' upper stopper members 83b, 83b' lower stopper member 90 load cell

Claims (4)

A mounting structure of the work platform to the tip of the boom in an aerial work vehicle configured by attaching the work platform to the tip of a boom provided on a vehicle body so as to be able to rise and fall,
a boom-side vertical member pivotally connected to the tip of the boom and extending vertically;
an upper horizontal link member having a base end side pivotally connected to the boom side vertical member and extending in a horizontal direction;
a workbench-side vertical member pivotally connected to the top end of the upper horizontal link member and extending vertically to fix the workbench;
a lower horizontal link member located below the upper horizontal link member and extending in the horizontal direction, the base end side of which is pivotally connected to the boom-side vertical member, and the tip end side of which is pivotally connected to the workbench-side vertical member; Equipped with a parallel link mechanism composed of
the workbench can be moved up and down with respect to the boom-side vertical member by the parallel link mechanism;
A contact member is provided on at least one of the upper horizontal link member and the lower horizontal link member,
A mounting structure of a work platform for a vehicle for work at height, wherein a regulation portion is provided on the boom-side vertical member for restricting upward movement of the work platform by coming into contact with the abutment member. 2. The aerial work vehicle according to claim 1, wherein the restricting portion is provided at a position that contacts the contact member when the upper horizontal link member and the lower horizontal link member are substantially horizontal. Mounting structure of the workbench in A load detector for detecting the load of the workbench,
The load detector is mounted on a mounting portion provided on the boom-side vertical member positioned above the upper horizontal link member,
The workbench-side vertical member abuts from above the load detector attached to the mounting portion in accordance with the downward movement of the workbench, which is vertically movable by the parallel link mechanism. 3. The mounting structure of a work platform for a vehicle for work at high altitude according to claim 1 or 2, further comprising a load applying member that applies a load from the outside. an additional load adjusting mechanism for adjusting the distance between the load applying member and the load detector;
An additional load can be applied to the load detector by reducing the distance by the additional load adjusting mechanism while the restricting portion and the contact member are in contact with each other. Item 4. A mounting structure for a workbench in the aerial work vehicle according to Item 3.

Images