JPS6359959B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is useful for assembling buildings at high places, lifting workers or materials for work such as painting, and for lifting unnecessary materials at construction sites. Regarding the lifting device used for loading and unloading, in particular, a pair of middle booms are pivoted in an X-shape at the center, and each middle boom has an upper boom and a lower boom that extend and contract in the length direction. It is a lifting device that is inserted through the upper and lower booms, and when the upper boom and the lower boom are extended and retracted respectively, and at the same time the pair of middle booms are rotated to raise the platform, the middle boom of each upper boom and each lower boom is The present invention relates to a synchronous telescoping machine for a lifting device that can regulate the amount of expansion and contraction of each.

[Conventional technology]

Assembly at high places such as highways and building construction,
For painting and repair work, a lifting device that raises and lowers a lifting platform is often used, and workers and materials are placed on the lifting platform to be lifted, and unnecessary building materials are loaded and unloaded. In this conventional elevating device, a pair of arms are pivoted at the center to form one set, and a pantograph-type extension/retraction mechanism is used in which a plurality of sets of arms are connected in the vertical direction (so-called scissor type). In this mechanism, in order to increase the maximum lifting height of the lifting device, it was necessary to increase the length of each set of arms or to increase the number of sets of arms to be connected. For this reason, if we were to design a lifting device that can increase the height that can be climbed, we would have to use multiple sets of pantographs.
The height of the lifting device becomes high when the pantograph is folded, making it cumbersome for workers to get on and off the lifting platform and to load and unload materials.

In order to eliminate this drawback, various proposals have been made in the past, and for example, a structure as disclosed in US Pat. No. 3,820,631 has also been proposed. In this proposed structure, a lower boom and an upper boom, which can move in a straight line with respect to the middle boom, are inserted into and removed from the middle boom, and the lower end of the lower boom is pivoted to the vehicle body with a pin. The upper end of the upper boom is pivotally supported on the platform with pins, forming an X-shape. With this structure, the length of the boom itself becomes longer, so the length of the platform can be reduced when it is in the folded state, and the platform can be lifted to a higher position.

However, in this invention, the mechanism that extends the lower boom and the upper boom from the middle boom is composed of a screw and a female screw that engages with the screw, so the movement speed of the lower boom and upper boom relative to the middle boom is slow, and the mechanism that extends the lower boom and upper boom from the middle boom is slow. It was impossible to make the platform respond. In addition, since the lower and upper booms are slid by a screw installed in the center of each middle boom, the total length of the lower and upper booms should be set to only about half the length of the middle boom. The structure was such that the length of the lower boom and upper boom, which are extended and retracted from the middle boom, could only be half the length of the middle boom, making it impossible to lift the platform higher.

Also, a structure has been proposed in which another boom is inserted into the boom to lengthen the entire length of the boom itself. For example, Patent Publication No. 119556
In Figure 4 of the drawing, the overall length of the boom is lengthened by inserting the middle boom with a thick diameter, the lower boom with a narrow diameter, and the upper boom, and then pulling out the inserted boom from the middle boom. , a structure has been proposed that allows the platform to be raised higher. However, in this structure, there is no mechanism to synchronize the amount of expansion and contraction between the lower boom and the upper boom, which are pulled out from the middle boom, and each moves independently.
The amount of movement is regulated by a link mechanism using bars. For this reason, the platform could not be lifted vertically and horizontally to a desired vertical height. In addition, when extending and retracting the lower and upper booms stored in the middle boom, a link mechanism formed by a bar is used to restrict the amount of movement of each, so the amount of movement is completely controlled. Since synchronization is impossible, it is not possible to connect the lower boom to the car body and the upper boom to the platform with pins, etc., and errors that cannot be synchronized due to the design must be corrected by rollers that are in contact with the car body and platform. It was something that should not have happened. For this reason, the platform suffers from the accumulation of looseness due to the large number of pivot points in the link mechanism, as well as the rolling motion caused by the rollers, resulting in a structure that is susceptible to sway, and is easily swayed by wind and other factors, causing a sense of uneasiness to workers. It was a restraining thing.

Due to these drawbacks, the lower and upper booms, which can be extended and retracted in the lengthwise direction, are inserted into the middle boom, and the lower and upper ends of the lower and upper booms are connected to the car body and the platform with pins, respectively, to prevent looseness. Lifting devices have also been proposed that can increase the height of the lifting platform while reducing the number of lifts (for example, Patent Application No. 41289 of 1982). However, in this newly proposed lifting device, the lifting platform cannot be lifted horizontally and vertically unless the lower and upper booms extend and contract the same amount with respect to the middle boom. Even if there was only a difference in the amount of expansion or contraction in any one of them, the lifting platform would lose its balance and could not be lifted while maintaining its horizontal position, making it extremely unstable.

[Problem that the invention seeks to solve]

The present invention provides a synchronous telescoping mechanism for a lifting device that eliminates the above-mentioned drawbacks.

The purpose of this invention is to synchronize the movement distances of a lower boom and an upper boom that are slidably inserted into each middle boom, and to synchronize the movement distances of each lower boom that slides from each middle boom. As a result, the aim is to synchronize all the extension and contraction amounts of the two lower booms and the two upper booms that extend and contract from both ends of the pair of middle booms, and to maintain the elevating mechanism in an X-shape at all times.

The upper and lower booms of each middle boom are connected by a flexible linking means to maintain the same movement speed, and each middle boom has a rotation angle that corresponds to the linear movement of the lower boom. A converting means for converting the lower boom to the lower boom is provided, and an interlocking means is interposed between the two converting means, thereby making it possible to make the respective movement amounts of both lower booms the same.

[Means for solving the invention]

The present invention comprises a movable vehicle body 1, a lifting platform 7 located above the vehicle body 1 that can be raised and lowered up and down, a pair of middle booms 10 rotatably supported in the center and combined in an X shape, and each middle boom. A lower boom 11 that slides in the length direction of 10 and whose lower end is connected to the vehicle body 1, and a lower boom 11 that moves in the length direction of each middle boom 10 and whose upper end is connected to the lifting platform 7. In order to make the amount of movement of the lower boom 11 and the upper boom 12 the same with respect to the upper boom 12 that has been moved, and the middle boom 10, the lower boom 11 and the upper boom 12 are linked and their movements are In a lifting device having a flexible linking means 27 for regulating the amount, each lower boom 11, 11
Rack 41, 42 provided along the length direction of
and a pinion 4 which is pivotally supported by each of the middle booms 10, 10 and meshes with the racks 41, 42, respectively.
6, 46, and independent sprocket wheels 4 that rotate in conjunction with each pinion 46, 46.
5, 45, and a pair of sprocket wheels 33, 33 that are rotatably held coaxially with the center of rotation of both intermediate booms 10, 10 and rotate at the same time.
and each sprocket wheel 45, 45 of each middle boom 10, 10 and this sprocket wheel 3.
A chain 37 stretched in a ring between 3 and 33,
38, and by synchronizing the rotation of both pinions 46, 46 with sprocket wheels 33, 45 and chains 37, 38, the amount of movement by which each lower boom 11, 11 expands and contracts from each middle boom 10, 10 is controlled. The present invention provides a synchronous expansion and contraction mechanism for a lifting device that is characterized by being held in the same position.

[Effect]

In the present invention, the lower boom and the upper boom are inserted so that they can slide in a straight line from the upper and lower ends of the middle boom, and the movement of the lower boom and the upper boom inserted into each middle boom is controlled by the linking means. regulated, and both extend and contract from the lower end or upper end of the middle boom with the same amount of movement. Also,
Each middle boom is provided with a conversion means that converts the amount of movement of the lower boom in a linear direction relative to the middle boom into rotational movement, and since an interlocking means is interposed between both conversion means, one When one lower boom extends or contracts, the other lower boom also extends or contracts at the same speed of movement, and as a result, both lower booms can be synchronized with the same amount of movement.

As a result, in a pair of middle booms combined in a pair of X shapes, the two lower booms extend and retract from the two lower ends and the two upper ends of both middle booms, and the two upper booms each have the same linear movement amount. The lifting platform, which is extendable and retractable and connected to the upper boom, is always maintained horizontally and can be moved up and down only in the vertical direction.

In addition, since the distance from the center of the middle boom combined in an X shape to the tips of the lower boom and upper boom can always be maintained at the same length, It can be connected to the vehicle body and the lifting platform with pins, and the lifting platform is firmly connected and held, so it will not shake due to wind or the like and can have extremely high stability.

〔Example〕

An embodiment of the present invention will be described below with reference to the drawings.

Fig. 1 is a side view showing the lifting platform lowered to the lowest position in this embodiment, Fig. 2 is a side view showing the lifting platform raised to the maximum height, and Fig. 3 is a side view showing the lifting platform lowered to the lowest position. FIG. 7 is a rear view showing a state in which the stand is raised to the maximum height position.

In this figure, reference numeral 1 denotes the body of a truck.A front wheel 2 and a rear wheel 3 are pivotally supported on the front, rear, left and right sides of the body 1, and a driver's seat is provided above the front wheel 2. Outriggers 5 for fixing the vehicle body 1 to the ground are fixed to the center and left and right sides of the rear, respectively. An elevating mechanism 6 is placed on the upper surface of the vehicle body 1, and an elevating platform 7 that moves up and down in the vertical direction is located above the elevating mechanism 6.
A handrail 8 is provided around the elevator platform 7.

The lifting mechanism 6 consists of four sets of telescopic booms,
Two sets of telescopic booms are arranged on both sides of the upper surface of the vehicle body 1, and each set of telescopic booms is composed of a middle boom 10, a lower boom 11, and an upper boom 12.

There is an
A connecting piece 14 is fixed to the lower end of the lower boom 11, and a connecting piece 15 is fixed to the upper end of the upper boom 12. Each lower boom 11
The connecting pieces 14 are rotatably connected by pins to four fixed pieces 16 fixed to the front, back, left, and right sides of the upper surface of the vehicle body 1, and the connecting pieces 15 of each upper boom 12 are connected to the lower side of the lifting platform 7, front, rear, left, and right. It is rotatably connected by pins to four fixed pieces 17 fixed to the.
The distance between the fixed pieces 16 and 17 of the fixed piece 17
The distance between them is the same, and as the telescopic boom rotates and extends in an X-shape, the vehicle body 1 and the lifting platform 7 become parallel to each other.

The middle booms 10 are made up of two pairs of middle booms 10 that are arranged parallel to each other with an interval between them. They are connected at the center by an operating shaft 18, and the axes of the operating shaft 18 and the connecting shaft 13 are aligned so that they are the same axis.

Hydraulic cylinders 19, 19 as actuating mechanisms are arranged in a V-shape between two positions close to the fixed piece 16 on the vehicle body 1 and the actuating shafts 18 and 18, and both hydraulic cylinders The cylinders 19, 19 are arranged to form an isosceles triangle with the operating axis 18 as the apex.

Next, FIGS. 4 and 5 explain in detail the internal structure of the telescopic boom, that is, the middle boom 10.

The middle boom 10 is formed by bending a thin steel plate, and has a hollow, square-shaped cross section with both ends open in the length direction. It is slidably inserted. The lower boom 11 is formed by bending a thin-walled steel plate and has an internally hollow rectangular cross-section.
2 is slidably inserted.

Fan-shaped shaft support pieces 20 and 21 are fixed to both ends of the middle boom 10, respectively, and a pair of guide rollers 22 and 23 are rotatably supported on the shaft support pieces 20 and 21, respectively. The guide rollers 22 are in contact with both the upper and lower sides of the lower boom 11, and the guide rollers 23 are in contact with both the upper and lower sides of the upper boom 12. A gearbox 24 is fixed to the end of the middle boom 10 close to the shaft support piece 21, and two sprocket wheels 25 and 26 as switching means are pivotally supported within the gearbox 24. .

The tip of the lower boom 11 (the deepest position in the middle boom 10) and the tip of the upper boom 12 are connected by a chain 27.
7 is wound around the outer periphery of the sprocket wheels 25, 26 in an S-shape, and this chain 27 forms a flexible linking means. By this chain 27, the lower boom 11 and the upper boom 12 are synchronized in the amount of expansion and contraction from the middle boom 10, and the lower boom 1
1 and the upper boom 12 move in and out of the middle boom 10 by the same amount of expansion and contraction.

Further, FIG. 5 shows a cross section of the center of the middle boom 10, and a band-shaped holder 28 is wrapped around and fixed to the center outer circumference of the middle boom 10, and one holder 28 has a side surface. A cylindrical connecting shaft 13 is projected, and an engaging piece 30 is fixed to the other holder 28 with a screw 29. The engaging piece 30 is inserted into an engaging groove 31 formed on the outer periphery of the connecting shaft 13. The pair of middle booms 10 can be rotated relative to each other by the connecting shaft 13 and the engagement piece 30. As a result, the pair of middle booms 10 are connected in an X-shape at their centers, and their rotation is maintained freely. A control ring 32 is rotatably inserted through the outer periphery of the connecting shaft 13, and a pair of sprocket wheels 33 are fixed in two rows to the outer periphery of the control ring 32. Further, a support shaft 34 is protruded from the holder 28 on the side opposite to the connection shaft 13 of the middle boom 10.
4, the operating shaft 18 is rotatably fitted therein.

Next, Figures 6 to 9 show the middle boom 1 of each group.
This figure shows a synchronized expansion and contraction mechanism that synchronizes the amount of expansion and contraction of the lower boom 11 and the upper boom 12 at zero.

The two telescopic booms are arranged in parallel at intervals as shown in FIGS. 6 and 7, and are close to the pivot piece 20 of the middle boom 10 of each telescopic boom. Conversion means 35, 3 are provided at the end.
6 is provided. Chains 37 and 38 as interlocking means are wound respectively between the conversion means 35 and 36 and the sprocket wheel 33, and the outer surfaces of the chains 37 and 38 are pivoted to the side surface of the middle boom 10. Tension pulley 3
9 and 40 are in contact. In addition, the connecting piece 1
4, racks 41 and 42 are fixed to the middle boom 10 so as to be spaced apart and parallel to each other, and the racks 41 and 42 are respectively located above and below the middle boom 10. Rack 4
1 and 42 are slidably inserted into the conversion means 35 and 36 in the length direction thereof, respectively.

FIGS. 8 and 9 show the converting means 36 in detail, and the other converting means 35 have the same configuration, and the configurations of both are the same except that the vertical positions are reversed in the figures. .

A pair of support pieces 43 are fixed at intervals near the shaft support piece 20 of the middle boom 10, and a drive shaft 44 is pivotally supported between the support pieces 43. A sprocket wheel 45 around which the chain 38 is wound is fixed to the outer surface of the drive shaft 44.
A pinion 46 is fixed to a drive shaft 44 on the support piece 43, and the drive shaft 44, sprocket wheel 45, and pinion 46 can all rotate simultaneously. The tooth surface of the rack 42 is engaged with this pinion 46, and a bearing 48 that is supported centrally on a support shaft 47 fixed between support pieces 43 is brought into contact with the upper surface of the rack 42. As a result, the rack 42 is retracted within the converting means 36 while meshing with the pinion 46.

Next, the operation of this embodiment will be explained.

First, an engine (not shown) attached to the vehicle body 1 is operated, and the engine drives a hydraulic pressure generating mechanism to generate hydraulic pressure, and this hydraulic pressure is supplied to each hydraulic cylinder 19, 19. Therefore, the pair of hydraulic cylinders 19 and 19 extend in the length direction and push the lower boom 11 and the upper boom 12 upward so as to pull them out from the middle boom 10.

At this time, since the racks 41 and 42 are fixed to each of the middle booms 10 in the pair, these racks 41 and 42 are moved in the direction of being pulled out from the conversion means 35 and 36, The racks 41, 42 rotate pinions 46 in the converting means 35, 36. The rotation of this pinion 46 is transmitted to the sprocket wheel 4 via the drive shaft 44.
5, each sprocket wheel 45 follows the meshing chains 37, 38. Each chain 37, 38 is wound around a sprocket wheel 33 at the same time, and since both sprocket wheels 33 are fixed to the same control ring 32, both chains 37, 3
8 is regulated by the rotation angle of both sprocket wheels 33, each chain 37, 38 moves by the same amount of movement, and each sprocket wheel 45 of both conversion means 35, 36 also rotates by the same rotation angle. , each rack 41, 42 is regulated by a pinion 46 and moves by the same amount. Each of the lower booms 11 is connected to the racks 41 and 42, so each lower boom 11 is connected to the rack 4.
1 and 42 determine the amount of extension from the middle boom 10, and the above-mentioned linkage determines the amount by which the lower boom 1 is extended.
The sliding movement from the middle boom 10 of 1 is the same amount of movement.

Further, when the lower boom 11 is extended more than the middle boom 10, the chain 27 fixed to the tip of the lower boom 11 is pulled, and the chain 27 is moved while rotating the sprocket wheels 25 and 26. Therefore, the lower end of the upper boom 12 connected to the chain 27 is pulled by the movement of the chain 27, and the upper boom 12 is pulled out from the upper end opening of the middle boom 10, and is synchronized by the chain 27. Therefore, the amount by which the lower boom 11 and the upper boom 12 are pulled out is the same.

In this way, each of the lower boom 11 and the upper boom 12 has their respective extension amounts regulated by chains, sprocket wheels, etc., and each slides by the same amount. This lower boom 11 and upper boom 1
2, the connecting pieces 14 and 14 and 15 and 15 fixed to the tips of the lower boom 11 and the upper boom 12 have the same spacing, so the middle boom 10 forms an X shape around the connecting shaft 13. It rotates and acts to lift the lifting platform 7 upward and horizontally. Then, in the ascent of this elevating platform 7,
Since each lower boom 11 and each upper boom 12 extend by the same amount from the middle boom 10, the lifting platform 7
It only rises straight upwards, and does not rise to the left or right.

FIG. 10 shows a state in which the lifting platform 7 has risen halfway, and FIGS. 2 and 3 show states in which the lifting mechanism 6 is fully extended and the lifting platform 7 has risen to its maximum height. There is.

Conversely, in order to lower the lifting platform 7, the hydraulic pressure in each hydraulic cylinder 19, 19 is reduced, and the lower boom 11 and the upper boom 12 are gradually pushed into the middle boom 10, contrary to the above. Connecting piece 1
4 and 15 is narrowed, the middle boom 10 is rotated around the connecting shaft 13, and the lifting platform 7 is lowered.

At this time as well, chains 27, 3
7, 38, sprocket wheel 25, 26, 3
3, 45, racks 41, 42, and pinion 46 work together, lower boom 11, upper boom 12
are pushed into the middle boom 10 by the same amount of sliding, and the lifting platform 7 moves straight downward while being maintained horizontally.

In this embodiment, when the lower boom 11 and the upper boom 12 are pulled out from the middle boom 10, the lower boom 11 is moved in order to synchronize the amount of movement of each.
Although the upper boom 12 and the chain 27 are connected to each other, the same effect can be obtained even if a metal rope or a rubber belt with wire is used instead of the chain 27. Needless to say.

〔Effect of the invention〕

Since the present invention is configured as described above, it is possible to increase the maximum height at which the platform can be raised and lowered compared to the conventional pantograph type link mechanism, and it is possible to raise the platform without stacking multiple sets of link mechanisms vertically. The limit can be increased. For this reason, the height from the ground to the lifting platform when it is in the reduced and folded state can be made smaller than its lifting capacity, and when the lifting device is moved, it does not come into contact with other structures, etc. It is possible to prevent problems such as

In the operation of the lifting mechanism, the lower boom and the upper boom housed in the middle boom are connected by connecting means, so the amount of movement of both of them relative to the middle boom is regulated, and from the middle boom to each lower boom and the upper boom. The amount of movement of the boom will be the same.

Furthermore, the linear motion of each lower boom in each middle boom is converted into rotational motion by the conversion means, and the converted rotational motion is regulated by the interlocking means. The amount of expansion and contraction relative to each other is maintained the same. As a result, the two middle booms extend and retract from each other.
The respective travel distances of the two lower booms and the two upper booms are all equally synchronized, and the telescoping mechanism is always
Since it is maintained in the same shape, the platform is always horizontal and can only be moved vertically.

Since the travel distances of the lower and upper booms are always synchronized, the distances from the center of the middle boom to the tips of the lower and upper booms are all the same, so the tip of the lower boom is pinned to the vehicle body. It can be connected with
The upper end of the upper boom can be connected to the lifting platform with a pin, making it possible to form a lifting mechanism with little play and extremely few pivot points, eliminating the risk of shaking. Therefore, the lifting platform is held stably, so that the worker does not feel uneasy and the work efficiency is improved.

[Brief explanation of the drawing]

Fig. 1 is a side view showing an embodiment of the elevating device with the elevating mechanism lowered to the lowest position; Fig. 2 is a side view showing the elevating mechanism in the fully extended state; Figure 3 is a rear view of the state in Figure 2, Figure 4 is a side sectional view showing the inside of the middle boom,
Fig. 5 is a longitudinal sectional view of the center of the middle boom, Fig. 6 is a plan view of the lifting mechanism, Fig. 7 is a side view of the same as above, Fig. 8 is a sectional view of the drive section, Fig. 9 is a side view of the same as above, 1st
FIG. 0 is a side view showing a state in which the elevating platform is slightly raised. 1... Vehicle body as a base, 6... Lifting mechanism, 7
... Lifting platform, 10 ... Middle boom, 11 ... Lower boom, 12 ... Upper boom, 27 ... Chain as linking means, 33, 45 ... Sprocket wheel, 37, 38 ... Chain, 37, 38
...Chain, 41, 42...Lack, 46...
pinion.

Claims (1)

[Scope of Claims] 1. A movable vehicle body 1, a lifting platform 7 located above the vehicle body 1 that can be raised and lowered, and a pair of middle booms 10 rotatably supported at the center and combined in an X shape; A lower boom 11 that slides in the length direction of each middle boom 10 and whose lower end is connected to the vehicle body 1, and a lower boom 11 that moves in the length direction of each middle boom 10 and whose upper end is connected to a lifting platform. In order to make the amount of movement of the lower boom 11 and the upper boom 12 the same with respect to the upper boom 12 connected to the middle boom 10 and the middle boom 10, the lower boom 11
In an elevating device having a flexible linking means 27 that links the upper boom 12 and the upper boom 12 to regulate the amount of movement of both, the lower boom 11 moves simultaneously with the lower booms 11, 11 and is provided along the length thereof. Track 41, 42
and a pinion 4 which is pivotally supported by each of the middle booms 10 and 10 and meshes with the racks 41 and 42, respectively.
6, 46, and independent sprocket wheels 4 that rotate in conjunction with each pinion 46, 46.
5, 45, and a pair of sprocket wheels 33, 33 that are rotatably held coaxially with the center of rotation of both middle booms 10, 10 and rotate at the same time.
and chains 37, 38 which are stretched independently in an annular manner between the sprocket wheels 45, 45 in each of the middle booms 10, 10 and the sprocket wheels 33, 33, and both pinions 46, 46. By synchronizing the rotations of the sprocket wheels 33, 45 and chains 37, 38, the movement amount by which each lower boom 11, 11 expands and contracts relative to each middle boom 10, 10 is kept the same. synchronous expansion and contraction mechanism.