JPS6327280B2 - - Google Patents

Description

[Detailed Description of the Invention] [Industrial Application Field] The present invention is useful for assembling buildings at high places, for lifting workers or materials upward for painting work, etc. Regarding lifting equipment used for loading and unloading materials,
In particular, it relates to a lifting device in which 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 inserted therethrough that extend and contract in the length direction thereof. In this lifting device, the upper boom and the lower boom can be extended respectively, and at the same time, when the pair of middle booms is rotated to raise the platform, the upper boom and the lower boom can be extended and contracted by the same amount. This invention relates to a synchronous extension and contraction mechanism for a lifting device.

[Conventional technology]

Assembly at high places such as highways and building construction,
For painting and repair work, a lifting device was used to raise and lower a lifting platform, and workers and materials were placed on this lifting platform to be lifted, and unnecessary building materials were 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 telescopic mechanism is used in which multiple sets of arms are connected vertically (so-called scissor type). 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, it would be necessary to use multiple sets of pantographs, and the height of the lifting platform with the pantographs folded would be higher than the ground, making it difficult for workers to lift and lower the platform. The work of getting on and off the platform, loading and unloading materials was troublesome.

In order to solve this runner-up problem, various proposals have been made in the past, such as U.S. Patent No. 3820631.
A structure as shown in the specification of the above patent has also been proposed.

In this proposed structure, a lower boom and an upper boom that can move in a straight line are inserted into and removed from the middle boom, the lower end of the lower boom is connected to the vehicle body with a pin, and the upper end of the upper boom is connected to the platform. They are assembled to form an X shape by connecting them with pins. With this structure, the length of the boom itself becomes longer, so the height of the platform can be lowered when it is folded, and the platform can be lifted to a higher position than the number of stages of the boom.

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 middle booms are slid by a screw installed in the center of each middle boom, the total length of each of the lower and middle booms is only about half the length of the middle boom. The platform could not be set, and the lower boom and upper boom, which can be extended and retracted from the middle boom, could only be operated by 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 this drawing, the lower and upper booms with narrow diameters are inserted into the middle boom with a thicker diameter, and the lower and upper booms inserted inside are slid from the middle boom to open the boom. A structure has been proposed in which the overall length of the platform is increased, thereby raising the platform 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 the lower boom and upper boom slide independently, and the movement of both The amount is regulated by a bar linkage. For this reason, it has been impossible to lift the platform vertically while maintaining a horizontal state, and it has been impossible to lift the platform horizontally to a desired vertical height position. Also,
When the lower boom and upper boom stored inside the middle boom expand and contract, the amount of movement is regulated by a link mechanism formed by a bar, so it is impossible to completely synchronize the amount of movement of both. It is. Therefore, it was not possible to connect the lower boom to the car body and the upper boom to the platform using pins, etc., and any errors that could not be absorbed had to be made by rollers that were in contact with the car body and platform. For this reason, the platform suffers from the accumulation of looseness due to the large number of pivot points due to the link mechanism, as well as the rolling motion caused by the rollers, resulting in a structure that is susceptible to sway and is extremely unstable as it is easily swayed by wind and other factors. This caused workers to feel uneasy.

In order to eliminate these drawbacks, proposals have been made, for example, as disclosed in patent application No. 41289 of 1982.

In these applications, a lower boom and an upper boom are inserted into the middle boom, the ends of the lower boom and the upper boom are connected by flexible connecting means, and the connecting means is pivoted to the middle boom. This is a structure in which the direction of movement is changed by means of a changing means. In this configuration, the upper boom is pushed out from the middle boom at the same time as the lower boom is pulled out from the middle boom, and the amount of movement of the lower boom and upper boom is regulated by the linking means. The amount of movement is the same, and the pair of middle booms pivoted at the center can rotate in an X-shape to push the platform vertically upward.

In this configuration, the lower boom and upper boom are housed inside the middle boom, so
When the lower boom and upper boom are extended from the middle boom, the total length can be extended to about three times the length of the middle boom, and the platform can be lifted higher than when it is folded. It is possible.

However, with this newly proposed lifting device, the four sliding amounts of the lower and upper booms pulled out from the two sets of middle booms must all be the same to maintain the platform vertically and horizontally. They could not be lifted, and their synchronization mechanisms were extremely complex.

[Problem that the invention seeks to solve]

In the present invention, in view of the above-mentioned drawbacks, a rack is formed on each side of the lower boom and the upper boom along the length thereof, and a pinion that engages easily is pivotally supported on each middle boom. , the purpose is to control all pinions to rotate synchronously by a chain.

For this reason, since the racks are formed in the length direction of each of the lower boom and the upper boom, the structure is extremely simple, and there is no need to separately provide a special structure. Furthermore, by synchronizing the rotation of the easily engaged pinions, the moving lengths of the lower and upper booms pulled out from the pair of middle booms can be made equal, which allows the boom mechanism to always form an X-shape. It can be operated so that

Since the distances from the ends of the lower and upper booms to the center of rotation of the middle boom are all the same, the lower and upper booms can be firmly connected to the vehicle body and platform using pins at both ends of the boom and the lower boom, respectively. This prevents the platform from shaking due to wind or the like. This synchronization mechanism has a structure in which a rack is formed in the length direction of each of the lower and upper booms, so the sides of the lower and upper booms can be used, allowing the boom to maintain its strength. Since the rack and the rack for regulating the moving length can be used in common in one mechanism, the structure is extremely simple.

[Means for solving problems]

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 10a and 10b that are rotatably supported in the center and combined in an X shape, and each Middle boom 10
Lower booms 11a and 1 slide in the longitudinal direction of a and 10b, and their lower ends are connected to the vehicle body 1.
1b, and upper booms 12a, 12b that slide along the length of each middle boom 10a, 10b and whose upper ends are connected to a lifting platform 7. A rack 26 formed in the length direction and a rack 2 formed in the length direction of each upper boom 12a, 12b.
7, a mutually independent pinion 24 that is pivotally supported at one end of each of the middle booms 10a, 10b and meshes with a rack 26 of the lower booms 11a, 11b, and an upper boom 12a that is pivoted at the other end of each of the middle booms 10a, 10b. , 12b, and each pinion 24, 2.
sprocket wheels 30, 42 connected to
, a chain 38 which is stretched in an annular manner between the sprocket wheels 30, 42 of each middle boom 10a, 10b and synchronizes the rotation of both sprocket wheels 30, 42, and a chain 38 which is coaxial with the center of rotation of both middle booms 10a, 10b. A control body 35 is located at and rotatably held, and each chain 3 of the middle booms 10a and 10b is formed on this control body 35.
Sprocket wheels 36a, 36 that mesh with 8
This invention provides a synchronous extension/contraction mechanism for an elevating mechanism characterized by comprising: (b).

[Effect]

In the present invention, racks are formed in the length direction of each of the lower boom and the upper boom, and each rack is engaged with a pinion,
The sprocket wheels connected to both pinions are always connected by a chain. For this reason,
Both pinions rotate in synchronization, and both the lower and upper booms are regulated so that they can extend and retract by the same amount than the middle boom, so the distance from the center of rotation of the middle boom to the tips of the lower and upper booms is can always be kept equal,
As a result, it is possible to raise the platform while maintaining it vertically and horizontally.

[Example] Hereinafter, an example of the present invention will be described with reference to the drawings.

Reference numeral 1 in the figure is the body of a truck. Front wheels 2 and rear wheels 3 are pivotally supported on the front, rear, left and right sides of the body 1, and a driver's seat 4 is provided above the front wheels 2. Outriggers 5 for fixing the vehicle body 1 in a fixed position are fixed to the left and right sides of the center and rear of the vehicle.

An elevating mechanism 6 is placed on the upper surface of the vehicle body 1. A elevating table 7 is fixed to the upper part of the elevating mechanism 6, and a handrail 8 is provided around the elevating table 7.

The lifting mechanism 6 consists of four sets of telescopic booms,
Each group of telescopic booms is a middle boom 10a~
d, lower booms 11a-d, upper booms 12a-
It is composed of d. The centers of the middle booms 10a and 10b and the middle booms 10c and 10d are respectively connected by connecting shafts 13a and 13b so as to be rotatable in an X-shape. The lower boom 1 is connected from the lower end opening of each middle boom 10a to 10d.
1a to 1d extendably extend through the middle booms 10a to 10d in the longitudinal direction, and each of the middle booms 10a to 10d
Upper booms 12a to 12d are extendably inserted into the middle booms 10a to 10d from the upper end opening in the longitudinal direction thereof. Connecting pieces 14a to 14d and 1 are provided at the ends of the lower booms 11a to 11d and the upper booms 12a to 12d, respectively.
5a to 5d are fixed to each other, and each connecting piece 14
a to d are fixed pieces 16 fixed to the four corners of the top surface of the vehicle body 1
The connecting pieces 15a to 15d are rotatably connected to fixed pieces 17a to 17d fixed to the four corners of the lower surface of the lifting platform 7 by pins. The distance between the fixed pieces 16a and 16b and the distance between the fixed pieces 17a and 17b are the same, so that even if the telescopic boom is extended in an X-shape, the vehicle body 1 and the lifting platform 7
are constructed so that they are always parallel.

The middle booms 10a to 10d are a set of two.
A pair of middle booms 10a, 10b and 10c
and 10d, these two sets are arranged parallel to each other with an interval between them, and the center of the opposing middle stage booms 10b and 10c located inside each set is rotatable by an operating shaft 18. connected, operating shaft 1
8 and the connecting shafts 13a, 13d are aligned so that they are on the same axis.

Fixing pieces 16a, 16b at the front and rear of the vehicle body 1
Hydraulic cylinders 19a, 19b are arranged in a V-shape between two positions close to the operating shaft 18, respectively, and both hydraulic cylinders 19a, 19b
are arranged to form an isosceles triangle with the operating axis 18 as the apex.

Next, FIGS. 4 and 5 show the internal structures of the above-mentioned telescopic booms, that is, the middle booms 10a to 10d. Since the structures of the four middle booms 10a to 10d are all the same, the branch numbers are It has been omitted.

The middle boom 10 has a hollow, square-shaped cross-sectional structure made by bending a thin steel plate, and a lower boom 11 is slidably inserted through the lower end of the middle boom 10. The lower boom 11 also has an internally hollow rectangular cross section made by bending a thin steel plate, and the upper boom 12 is inserted into the lower boom 11 from the other open end of the middle boom 10.
is slidably inserted.

Further, fan-shaped shaft support pieces 20 and 21 are fixed to the left and right ends of the middle boom 10, respectively.
A pair of guide rollers 22a, 22b, 23a, 23b are rotatably supported on the shaft support pieces 20, 21, respectively.
a and 22b are on the upper and lower surfaces of the lower boom 11, and a pair of guide rollers 23a and 23b are on the upper and lower boom 1.
The upper and lower surfaces of 2 are in contact with each other. Also,
Pinions 24 and 25 are mounted on the shaft support pieces 20 and 21 in parallel with the axes of the guide rollers 22 and 23, respectively.
is pivotally supported, and the lower boom 11 and upper boom 1
2 has racks 26 and 27 fixed on its sides so as to be parallel to each other in the length direction, and the rack 26 has a pinion 24 and the rack 27
The pinions 25 are engaged with each other.

FIG. 5 shows a cross section taken along the line A--A in FIG.
A drive shaft 28 is pivotally supported between them, and a pinion 24 that meshes with a rack 26 is pivotally attached to the center of the drive shaft 28. A shaft support piece 2 is provided on both sides of this pinion 24.
Each of the drive shafts 28 between the collars 2 and 0 has a collar 2.
9a and 29b are inserted therethrough, and a sprocket wheel 30 is pivotally attached to the outer end of the shaft support piece 20a of the drive shaft 28.

In addition, FIG. 6 shows a set of middle booms 10a, 10.
This figure shows a cross section of the center part of the middle boom 10a, 10b, and band-shaped holders 31a, 31b are wrapped around and fixed to the center outer periphery of the middle booms 10a, 10b, respectively.
A cylindrical connecting shaft 13a is fixed to the side surface of one holder 31a, and an engagement piece 33 fixed with a screw 32 is fixed to the side surface of the other holder 31b. is slidably engaged with an engagement groove 34 formed on the outer periphery of the connecting shaft 13a. As a result, the pair of middle booms 10a and 10b are connected in an X-shape at their centers, and their rotation is maintained freely.

A control ring 35 as a control body is rotatably inserted through the outer periphery of the connecting shaft 13a, and a pair of sprocket wheels 36a and 36b are fixed to the outer periphery of the control ring 35. Also,
A support shaft 37 is protruded from the holder 31b on the side opposite to the connection shaft 13a of one middle boom 10b, and the operating shaft 18 is rotatably connected to the support shaft 37.

Next, FIG. 7 shows the interlocking mechanism in this embodiment.

The pinion 24 is supported by a drive shaft 28, and a sprocket wheel 30 is fixed to the end of the drive shaft 28. The pinion 25 is supported by a drive shaft 41, and a sprocket wheel 42 is fixed to the end of the drive shaft 41. An endless chain 38 is wound annularly between the pair of sprocket wheels 30, 42, and the inner periphery at the center of the annular chain 38 meshes with the upper and lower surfaces of the sprocket wheel 36b, respectively. There is a sprocket wheel 30,3
6b, 42, drive shaft 28, 41, pinion 24,
25 are all rotated synchronously by a chain 38. Further, tension gears 39 and 40 are pivotally supported on the left and right sides of the sprocket wheel 36b, which lightly contact the outer periphery of the chain 38 and bias the chain 38 so that the chain 38 is surely engaged with the sprocket wheel 36b.

Although not shown in FIG. 7, a chain is wound around the other sprocket wheel 36a in a similar manner.

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 mechanism to generate oil pressure.

This oil pressure is supplied to each hydraulic cylinder 19a, 19b. For this reason, a pair of hydraulic cylinders 19
a, 19b extends in the length direction and is raised while rotating the middle booms 10a to 10d around their centers, and similarly pulls out the lower booms 11a to 12a and the upper booms 12a to 12d from the middle booms 10a to 10d. . At this time, the racks 26, 27 fixed to the lower booms 11a to 11d and the upper booms 12a to 12d
slides from the middle booms 10a to 10d while rotating the pinions 24 and 25. but,
Since the pinions 24 and 25 are connected by sprocket wheels 30 and 42 and a chain 38, respectively, the rotational movement of both pinions 24 and 25 is restricted so that they rotate in the same rotation direction and at the same rotation speed.

Here, if the diameters of the pinions 24 and 25 are the same, the amount of movement of the racks 26 and 27, that is, the amount of extension of the lower booms 11a-d and the upper booms 12a-d from the middle booms 10a-d will be the same. From this, lower booms 11a-d and upper booms 12a-d are pulled out from each middle boom 10a-d.
are synchronously expanded by the same amount of movement.

Also, when the chain 38 rotates, the middle boom 1
Sprocket wheel 3 located in the center of 0b
6b rotates as a result, the control ring 35 is also rotated, and at the same time, the other sprocket wheel 36a is rotated, and the other chain (not shown) provided on the other opposing middle boom 10a is rotated. ) is also regulated at the same time, and as described above, the racks 26, 27 and pinions 24, 25 match the extension amounts of the lower boom 11a and the upper boom 12a extending from the other middle boom 10a. Therefore, the extension amounts of the pair of lower booms 11a, 11b and the pair of upper booms 12a, 12b of the telescopic booms connected in an The distances to each of the connecting pieces 14a, 14b, 15a, and 15b are all the same, and the pair of opposing middle booms 10a to 10d always rotate in an X-shape around the connecting shaft 13a to lift the lifting platform 7. It works like this.

When the platform 7 is raised, each of the lower booms 11a to 11d and the upper booms 12a to 12d extend by the same amount of movement, so that the platform 7 only rises straight upwards, and the platform 7 deviates from side to side. It is something that never rises.

Figure 8 shows the state in which the lifting platform 7 has been raised halfway, and Figures 2 and 3 show the state in which the lifting mechanism 6 is fully extended and the lifting platform 7 has risen to its maximum height. It shows.

Conversely, in order to lower the lifting platform 7, the hydraulic pressure in both hydraulic cylinders 19a, 19b is reduced to reduce the length of the hydraulic cylinders 19a, 19b, and contrary to the above, the middle booms 10a to 10d are The lower booms 11a to 11d and the upper booms 12a to 12d are gradually pushed into the middle boom 1.
Connecting pieces 14a-d and 15a-d at 0a-d
A pair of middle booms 10a facing each other
and 10b, 10c, and 10d are connected by connecting shafts 13a, 1
By rotating in an X shape around 3b, the lifting platform 7
lower. At this time as well, the chain 38, sprocket wheels 30, 36, 4
2. The racks 26, 27 and the pinions 24, 25 work together, and the lower booms 11a to 11d,
The upper booms 12a to 12d are pushed into the middle booms 10a to 10d by the same amount of movement, respectively, and the lifting platform 7
will be gradually lowered while remaining horizontally pointing straight downward.

〔effect〕

Since the present invention is configured as described above, in the mechanism for vertically moving the elevator platform by extending and contracting the upper boom and the lower boom from the middle boom, the amount of expansion and contraction of the upper boom and the lower boom relative to the middle boom can be regulated to be the same. The lifting platform can be moved up and down in a straight line above the lower boom, and the lifting mechanism, which is configured to easily deviate to the left or right during the vertical movement of the lifting platform, is precisely controlled in synchronization. be able to. Further, since racks are formed in the length direction of each of the lower boom and the upper boom, the structure is simple, assembly and manufacturing are easy, and the structure of the synchronization mechanism is extremely simple.

[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; 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,
Figure 5 is a cross-sectional view taken along arrow A--A in Figure 4, Figure 6 is a vertical cross-sectional view of the center of the middle boom, Figure 7 is a partial perspective view showing the configuration of the synchronization mechanism, and Figure 8 is a view of the lifting platform. FIG. 3 is a side view showing a slightly raised state. 1... Vehicle body, 6... Lifting mechanism, 7... Lifting platform, 10a
~d...middle boom, 11a~d...lower boom, 1
2a-d...Upper boom, 24, 25...Pinion,
26, 27...Rack, 30, 36, 42... Sprocket wheel, 35... Control ring as a control body, 38... Chain.

Claims (1)

[Claims] 1 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 10a and 10b that are rotatably supported in the center and combined in an X shape, and each middle boom 10a. ,10b
The lower booms 11a and 11b whose lower ends are connected to the vehicle body 1 slide in the length direction, and the middle booms 10a and 10b slide in the length direction, and their upper ends move up and down. In a lifting device consisting of upper booms 12a, 12b connected to a platform 7, a rack 26 formed in the length direction of each lower boom 11a, 11b, and a rack 26 formed in the length direction of each lower boom 11a, 11b,
A rack 27 formed in the length direction of the middle boom 2b, a mutually independent pinion 24 that is pivotally supported at one end of each middle boom 10a, 10b and meshes with a rack 26 of the lower boom 11a, 11b, and each middle boom 10.
The upper boom 12 is pivotally supported at the other ends of a and 10b.
a, 12b, the sprocket wheels 30, 42 connected to the pinions 24, 25, and the sprocket wheels 30, 42 of the middle booms 10a, 10b. A chain 38 is provided to synchronize the rotation of both sprocket wheels 30, 42, and a control body 3 is rotatably held coaxially with the center of rotation of both intermediate booms 10a, 10b.
5, and sprocket wheels 36a and 36b formed on the control body 35 and meshing with the respective chains 38 of both middle stage booms 10a and 10b.