JP2000120016A - Screed device in paver - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain twice or more of paving width of a main screed width by elongating a pair of left-right sub-screeds disposed on the rear-section side of a main screed while accurately setting the length of expansion and contraction easily by simplifying the expansion and contraction mechanism, and to conduct paving operation efficiently. SOLUTION: A pair of left-right movable supporting frames 8, 9 are arranged to a fixed supporting frame 7, and a main screed 1 is hung to the fixed supporting frame 7 and sub-screeds 2, 3 having width from the half of the main screed 1 to the same width to the movable supporting frames 8, 9 respectively. A pair of the sub-screeds 2, 3 are disposed on the rear-section side of the main screed 1, and shrunk compactly under the state in which the sub-screeds 2, 3 are superposed mutually before and behind under a normal state, while two two-stage type hydraulic cylinders 10, 11 for expansion and contraction are arranged bilaterally to the fixed supporting frame 7 of the main screed 1, and the movable supporting frames 8, 9, from which the sub-screeds 2, 3 are hung, are expanded and contracted and moved in the paving width direction respectively by these two-stage type hydraulic cylinders 10, 11.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a screed device for a paving machine having a screed which can be expanded and contracted according to the width of a road to be paved.

[0002]

2. Description of the Related Art Conventionally, as a screed device in a paving machine, there is known a screed device having a structure in which sub-screeds having a width of about 1/2 of the width of the main screed are arranged on the left and right sides on the front or rear side of the main screed. The left and right sub-screeds are expanded and contracted in the pavement width direction according to the pavement width. However, even when the secondary screed is extended to the maximum length, the pavement width is approximately twice or less the width of the main screed. The screed must be bolted and attached, which requires labor and labor and reduces the work efficiency.

[0003] For this reason, for example, Japanese Patent Application Laid-open No. Hei 7-10252
As described in Japanese Patent Application Publication No. 1 (1993) -1994, first support blocks are vertically movably mounted on both sides of a rear surface of a main screed, and a first hydraulic cylinder and a first hydraulic cylinder are mounted on these first support blocks.
The first and second guide rods are respectively mounted on the left and right first guide rods so that a pair of left and right first telescopic screeds are slidably supported in the pavement width direction, and these first telescopic screeds are respectively expanded and contracted by a first hydraulic cylinder. Further, a second support block on which the second hydraulic cylinder and the second guide rod are mounted is attached to the rear surfaces of the first telescopic screeds on the left and right in the same manner as described above, and these second hydraulic cylinder and the second guide rod are interposed. A screed device configured to expand and contract the second telescopic screed in the width direction of the pavement has been developed.

[0004]

However, in the structure of the screed device, the main screed is provided with the first hydraulic cylinder and the first guide rod, which are the telescopic mechanism of the first telescopic screed, and the first screed is mounted on the first telescopic screed. Since the second hydraulic cylinder and the second guide rod, which are the telescopic mechanism of the second telescopic screed, are provided, the whole apparatus becomes large and complicated, and the assembling work is troublesome, and the weight and weight are reduced. The cost is greatly increased, and at the time of pavement, the pavement thickness must be adjusted by individually vertically moving and adjusting all of the pair of left and right first telescopic screeds and the pair of left and right second telescopic screeds, which is complicated. There are problems such as the necessity of an operation and the difficulty of accurate adjustment.

On the other hand, in order to simplify the operation of the telescopic screed, telescopic screeds having substantially the same width as the main screed are arranged on the front and rear surfaces of the main screed. When the telescopic screeds are arranged on the surface, not only does a wide space in the front-rear direction be required for arranging the respective telescopic mechanisms, but also the main screed is spaced from the front telescoping screed from the rear end of the paving machine. And a strong suspension structure must be provided at the rear, and a large amount of pavement material carried out from the rear end of the paver to the road surface stays on the front side of the main screed. Since the traction resistance of the pavement machine increases and hinders pavement work, it is necessary to install a leveling adjustment plate in front of the main screed to adjust the amount of pavement material sent to the main screed. No et al.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to simplify the structure of the entire apparatus and to easily assemble and dispose the apparatus on a pavement machine. Another object of the present invention is to provide a screed device for a pavement machine which enables highly accurate operation.

[0007]

In order to achieve the above object, a screed device in a paving machine according to the present invention is characterized in that a rear portion of a main screed disposed below a rear end of the paving machine is provided. A sub-screed extending and contracting in one of the left and right directions from the main screed and a sub-screed extending and contracting in the other direction are arranged in a mutually superposed state, and the width of these sub-screeds is set to And when these sub-screeds are extended to the maximum extent, the overall width of the screed is at least twice as large as the main screed.

In the screed device for a paver having the above-mentioned construction, the invention according to claim 2 is characterized in that the two sub-screeds are arranged symmetrically at the rear of the main screed.
In addition, flat L-shaped notches are formed in the front half of one sub-screed and the rear half of the other sub-screed from the inner end surface to the outer end, and the two sub-screeds are mutually connected through these notches. By engagement, the width between the outer end faces of the two sub-screeds is set to a contraction width substantially equal to the width of the main screed.

According to a third aspect of the present invention, there is provided a screed device for a paver according to the first or second aspect, wherein the fixed screed is provided at a rear end of the pavement machine. A left and right movable support frame with a sub screed attached to the lower end is attached to the lower end, and a left and right movable support frame is mounted movably in the left and right direction, and a pair of left and right fluid pressure cylinders are symmetrically coaxial with the fixed support frame. The left and right movable support frames are configured to extend and contract in the left and right directions by these fluid pressure cylinders.

[0010]

When the pair of sub-screeds are contracted, these sub-screeds overlap each other at the rear of the main screed to have a contraction width equal to the width of the main screed. When these sub-screeds are extended in the left-right direction with respect to the main screed from this state, the entire width of the screed is increased to twice or more and almost three times the main screed. As described above, the pair of sub-screeds are configured to expand and contract in the left-right direction at the rear side of the main screed, so that the main screed is arranged at the rear end of the paver close to the discharge end of the pavement material. Therefore, it is not necessary to provide a leveling adjustment plate for adjusting the feed amount of the pavement material in front of the main screed. Further, the adjustment of the pavement thickness can be easily performed by vertically moving only the pair of sub-screeds with respect to the main screed adjusted to a certain height.

Further, as described above, since the pair of sub-screeds are disposed at the rear of the main screed, the expansion and contraction mechanism of these sub-screeds is such that both sub-screeds are movable. The support frame is disposed so as to be able to expand and contract symmetrically with respect to the fixed support frame of the main screed, and a pair of left and right fluid pressure cylinders are disposed coaxially on the fixed support frame of the main screed to allow these fluids to flow. That the movable support frames of the sub-screeds on both sides are extended and contracted by the pressure cylinder,
A telescopic mechanism that can be operated simply and reliably can be configured.

Further, as the pair of sub-screeds, a flat L-shaped notch portion engageable with the front half of one sub-screed and the rear half of the other sub-screed. Is formed, when both the sub-screeds are contracted, the two sub-screeds are smoothly and compactly stored in the rear portion of the main screed while being engaged with each other via the L-shaped cutouts. In this state, it is as if the shape and size of one sub-screed were simplified to further simplify the structure of the entire screed device, and these sub-screeds were symmetrical in the left-right direction on the same axis along the rear surface of the main screed. It is necessary to adjust the height of the iron part of both sub screeds with respect to the bottom of the main screed, that is, the iron part that sets the pavement thickness to a certain thickness. By moving the two sub-screeds up and down as described above, the workability can be improved easily and accurately, and the paving material discharged from the paving machine side to the front side of the screed is sent to the iron part of the main screed. Subsequently, the iron can be continuously pressed by the iron portion of these sub-screeds to a constant thickness, so that efficient pavement can be performed.

[0013]

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a block diagram showing a first embodiment of the present invention; FIG.
Is a main screed having a width substantially equal to the width (lateral width) of the paving machine main body A (shown in FIG. 6).
3 are arranged. The width (width) of these sub screeds 2 and 3 is 以上 or more of the width of the main screed 1 and less than 1;
Preferably, the width between the outer end faces of the sub screeds 2 and 3 is reduced to the width of the main screed 1 when the sub screeds 2 and 3 are contracted and overlapped back and forth. It is configured to be equal.

Further, the pair of front and rear sub-screeds 2,
Rear ends of side plates 6 and 6 for setting the width of the pavement are fixed to the outer end surface of the main screed 1, and these side plates 6 and 6 are protruded forward by an appropriate distance from the front surface of the main screed 1. It protrudes in parallel toward the front so that A flattening adjustment plate 14 is provided in front of the rear sub-screed 2 with a thickness interval in the front-rear direction of the front sub-screed 3. The end is fixed to the inner surface of the side plate 6 attached to the rear side sub screed 2. Accordingly, when the front and rear sub screeds 2 and 3 are contracted, the front sub screed 3 has a structure interposed between the rear sub screed 2 and the raking adjustment plate 14. The main screed 1 and the sub screeds 2 and 3 are formed of a metal plate in a horizontally elongated box shape, and a bottom plate having a front end edge curved upward in a sled shape is fixed to the bottom surface thereof to form a pavement material. Are formed in the iron portions 1c, 2c, and 3c for pressing.

The main screed 1 is integrally fixed and supported at the lower end of the fixed support frame 7, while the sub screeds 2, 3 superposed one on the other are moved in the left and right directions with respect to the fixed support frame 7, respectively. It is suspended from the lower ends of possible left and right movable support frames 8 and 9. The fixed support frame 7 has side plates 7b projecting rearward at right angles to both left and right ends of a front plate 7a equal to the width of the main screed 1,
7b has a structure in which partitioning plates 7c, 7c arranged side by side at appropriate intervals in the center part of the front plate 7a and provided at a constant distance in the center of the front plate 7a and projecting rearward, and both side plates 7b, The lower end facing surface of 7b is integrally fixed to both side end surfaces of the main screed 1.

On the upper part of the fixed support frame 7, the left and right movable support frames 8 and 9 are respectively attached to the main screed 1.
A pair of left and right two-stage hydraulic cylinders 10 and 11 that move in the pavement width direction (left and right direction) along the front end face are arranged on the same axis with their bottom surfaces abutting each other.
Connect both ends of the left two-stage hydraulic cylinder 10 to the left side plate 7b.
The right and left two-stage hydraulic cylinders 11 are fixedly mounted between the right side plate 7b and the partition plate 7c.
First-stage telescopic rods 10a, 11 with the open ends of 10 and 11 housed inside from the left and right side plates 7b outward.
a and the second-stage telescopic rods 10b and 11b are configured to extend in the pavement width direction. Further, a pair of front and rear fixed guide tubes 12 having a pair of short cylinders are provided on both side plates 7b, 7b of the fixed support frame 7 in parallel with the front and rear portions with the open ends of the two-stage hydraulic cylinders 10, 11 at the center. , 13 are fixed to and supported by the side plates 7b, 7b, respectively.

The movable support frames 8 and 9 are formed in a symmetrical shape. In other words, these movable support frames 8, 9 are opposed to the inner and outer plates 81, 91, 8 at the left and right with a slightly wider interval than the width of the sub-screeds 2, 3.
2, 92 and the inner and outer plates 81, 82 of the left movable support frame 8
The upper and lower plates 84, 94 and the upper plates 83, 93 and the lower and upper plates 83, 93 are disposed at the upper and lower portions between the inner and outer plates 91, 92 of the movable support frame 9 on the right and left sides. , 92, a pair of front and rear guide pipes 85, 95 each having a fixed length are fixed between the front and rear upper surfaces of the opposing surfaces, and these guide pipes 85, 95 are respectively attached to the left and right side plates 7b of the fixed support frame 7. , 7b, a pair of front and rear fixed guide cylinders 1
2 and 13 are slidably inserted and supported in the left and right direction, and these guide pipes 85 and 95 are inserted into guide pipes 85 and 95.
Telescopic guide pipe 8 arranged to extend and contract outward from 95
Outer ends (tips) of 6, 96 are fixed to upper end portions of the outer plates 81, 91, respectively.

Further, guide rods 87, 97 are fixed to the front and rear lower portions of the opposing surfaces of the upper plates 83, 93 and the inner plates 82, 92, respectively, and these guide rods 87, 97 are fixed to the left and right movable support frames 8, 9 respectively. The sliding short cylinders 88 and 98 fixed to the upper ends of the lower plates 84 and 94 are slidably fitted and supported, respectively, and the lower ends of the lower plates 84 and 94 bent in the horizontal direction and the outer plate
Hydraulic cylinders 15 and 16 are attached vertically to lower ends of the horizontal bent 81 and 91, respectively, and the lower ends of the rods of these hydraulic cylinders 15 and 16 are attached to the front and rear auxiliary screeds 2 and 3 respectively.
And the auxiliary screeds 2 and 3 are suspended by the lower plates 84 and 94 and the outer plates 81 and 91 so as to be adjustable in height from the pavement surface via the hydraulic cylinders 15 and 16 respectively. I have. As shown in FIG. 6, a vertical shaft 1 is attached to the front and rear sides of the hydraulic cylinders 15, 16 as shown in FIG.
7 and 17 are projected and these vertical shafts 17 are attached to the secondary screed 2,
The sub screeds 2 and 3 are vertically moved while the posture of the sub screeds 2 and 3 is kept constant by passing the sub screeds 3 through the lower horizontal bent portions of the lower plates 84 and 94 and the outer plates 81 and 91.

Also, both side plates of the fixed support frame 7
Left and right two-stage hydraulic cylinders 1 are provided on inner plates 82, 92 of left and right movable support frames 8, 9 disposed inward from 7b, 7b.
Holes 89 and 99 through which 0 and 11 are inserted are
2 and 92 are configured to move on the left and right two-stage hydraulic cylinders 10 and 11 in the left-right direction, respectively. Furthermore, in the two-stage hydraulic cylinder 10 on the left side, the distal end of the first-stage telescopic rod 10a is connected to the upper plate of the movable support frame 8 on the left side.
The movable support frame 10 is expanded and contracted in the left-right direction by fixing the distal end of the second-stage telescopic rod 10b to the outer plate 81 and expanding and contracting these elastic rods 10a and 10b. Similarly, in the two-stage hydraulic cylinder 11 on the right, the tip of the first-stage telescopic rod 11a is fixed to the upper plate 93 of the movable support frame 9 on the right, and
The movable support frame 11 is expanded and contracted in the left and right direction by fixing the tip of the stepped telescopic rod 11b to the outer plate 91 and expanding and contracting these telescopic rods 11a and 11b.
It should be noted that other fluid pressure cylinders may be used instead of the two-stage hydraulic cylinder.

The hydraulic cylinders 15 and 16 are provided so that the height of the iron portions 2c and 3c of the auxiliary screeds 2 and 3 from the pavement surface is the same as the height of the iron portion 1c of the main screed 1. The hydraulic cylinders 15 and 16 are used to adjust the front and rear sub screeds 2 and 3 to the left and right sides by adjusting the heights of the sub screeds 2 and 3 up and down to make the pavement thickness constant over the entire width. The lower ends of the lower plates 84 and 94 and the outer plates 81 and 91 of the left and right movable support frames 8 and 9 are not limited to the structures supported by the movable support frames 8 and 9.
And the lower ends of the sub screeds 2 and 3 are integrally fixed to the upper surfaces of the sub screeds 2 and 3, respectively. The movable screeds 2 and 3 with respect to the main screed 1 are connected to the movable screeds 2 and 3 by moving the movable support frames 8 and 9 up and down with respect to the fixed support frame 7 by connecting the movable support frames 8 and 9 vertically via a screw mechanism or the like.
The height adjustment from the road surface may be performed.

In the screed device thus constructed, as shown in FIG. 6, the fixed support frame 7 of the main screed 1 has right and left base ends pivotally attached to both side surfaces of the paving machine main body A so as to be vertically rotatable. The pivotal portion of the left and right arm members 21 is fixed and supported at the distal end of the arm member 21 and is vertically movably supported by a hydraulic cylinder 22 mounted on the main body A. Hydraulic cylinders connected 23
The height of the main screed 1 with respect to the road surface, that is, the pavement thickness is adjusted by raising and lowering the entire screed device by rotating the distal end portions of the left and right arm members 21 up and down by operating the hydraulic cylinder 22 on the base end side. It is configured to be.

In order to perform the pavement work, after the asphalt mixture is put into the hopper 24 mounted on the main body A, the main body A is slowly moved on the road surface to be paved and is stretched on the bottom side of the main body A. And driving around the bar conveyor 25
The asphalt mixture is supplied onto the bar conveyor 25 from the lower end of the opening of the hopper 24, is conveyed backward by the bar conveyor 25, and is discharged from the discharge end to the road surface. Further, the asphalt mixture discharged on the road surface is spread in the width direction of the road surface by the screw gombar 26 disposed at the lower rear portion of the main body A, and then paved to a predetermined width and thickness by the screed device. Things.

At this time, the width of the screed device is adjusted in accordance with the width of the road surface to be paved, and the adjustment is performed by adjusting the left and right two-stage hydraulic cylinders 10 provided on the fixed support frame 4. The first and second telescopic rods 10a, 11a and 11b and the second telescopic rods 10b, 11b are sequentially extended so that the front and rear sub-screeds 2, 3 are sequentially extended from the main screed 1 in the width direction of the pavement. It is performed by setting the width of the pavement by the side plates 6 and 6 fixed to the outer end surfaces of a few.

When paving with a minimum width, the first and second telescopic rods 10a of the two-stage hydraulic cylinders 10, 11 are used.
10b, 11a, and 11b are completely contracted and stored in the cylinder. In this stored state, as shown in FIG. 2, telescopic guide pipes 86 and 96 are stored in guide pipes 85 and 95 of left and right movable support frames 8 and 9, respectively, and outer plates 81 and 91 are placed in intermediate upper plate 83, respectively. The inner lower plates 84 and 94 are in contact with the outer surfaces of the inner plates 82 and 92 by sliding the upper sliding short tubes 88 and 98 inward along the guide rods 87 and 97. Abut on the outer surface of the intermediate upper plate 83,
The guide pipes 85 and 95 that integrally connect the 93 and the inner plates 82 and 92 slide inward in the fixed guide cylinders 12 and 13 that are inserted into the side plates 7b and 7b of the fixed support frame 7, respectively. It moves and moves and is in a state of being stored in both sides of the fixed support frame 7, respectively.

Accordingly, the sub-screeds 2, 3 suspended respectively by the outer plates 81, 91 and the lower plates 84, 94 firstly
After the telescopic guide pipes 86 and 96 have moved inward to the positions stored in the guide pipes 85 and 95, the guide vip 85,
The inward movement of 95 causes it to be further moved into the fixed support frame 7, and in the most contracted state, as shown in FIG. The width between the outer end faces of the sub screeds 2 and 3 is in a contracted state in which the width is equal to the width of the main screed 1. In this state, when the paving machine main body A is advanced in the longitudinal direction of the road surface, the paving material (asphalt mixture) discharged on the road surface is paved by the iron portion 1c of the main screed 1 to a flat and uniform thickness over the entire width. Is what you do.

Next, when performing pavement wider than the main screed 1, first, the left and right two-stage hydraulic cylinders 10, 11
When the first-stage telescopic rods 10a, 11a are extended, the intermediate upper plates 83, 93 of the left and right movable support frames 8, 9, which are integrally fixed to the rod ends, are pushed forward, and the intermediate upper plates 83, 93 are pushed forward. The guide pipes 85 and 95 that integrally connect the 93 and the inner plates 82 and 92 are pulled out through the fixed guide tubes 12 and 13 in the width direction of the road with the telescopic guide pipes 86 and 96 stored therein, respectively. The outer plates 81, 91 and the intermediate lower plates 84, 94 respectively suspending and supporting the intermediate upper plate 83,
The two sub-screeds 2, 3 are moved together in a state of contacting the inner plate 82 and the inner plates 82, 92 in the width direction of the road from the rear portion of the main screed 1, that is, one (front) sub-screed 2.
To the left and the other (rear) sub-screed 3 to the right.

When the outer ends of the two sub-screeds 2 and 3 do not reach the ends of the pavement width on the road surface even when the first-stage telescopic rods 10a and 11a of the two-stage hydraulic cylinders 10 and 11 extend to the maximum. ,
Next, the second-stage telescopic rods of the two-stage hydraulic cylinders 10 and 11
Extend 10b and 11b. When these rods are extended, the outer plates 81, 91 of the left and right movable support frames 8, 9 are pushed outward as shown in FIG.
While pulling out the telescopic guide pipes 86 and 96 from 95, and sliding the upper sliding short cylinders 88 and 98 of the intermediate lower plates 84 and 94 with the guide rods 8
The two sub-screeds 2 and 3 are further moved outward while sliding outward along the lines 7 and 97, and when the pavement width is reached, the sub-screeds 2 and 3 are stopped and paving work is performed.

The two-stage hydraulic cylinders 10, 11-1
Second-stage telescopic rods 10a and 11a and second-stage telescopic rods 10b and 11
The expansion and contraction order of b is such that, after activating the second-stage telescopic rods 10b and 11b, and then activating the first-stage telescopic rods 10a and 11a,
The main screed 1 and the two sub screeds 2,
3 can be expanded and contracted.

In the above-described embodiment, the screed device having a structure in which the sub screeds 2, 3 having a constant thickness in the front-rear direction over the entire width are superimposed one on the other is described. In the front half of the secondary screed 2 ', a notch 4 cut out in a plane L shape from the inner end face to the outer end of the secondary screed 2' is formed, and in the latter half of the other secondary screed 3 '. Alternatively, a structure may be adopted in which a cutout portion 5 cut out in a plane L shape from the inner end surface to the outer end portion of the sub screed 3 'is formed.

The lateral dimensions of the cutouts 4, 5 formed in the left and right sub-screeds 2 ', 3' are as follows.
The width of the front and rear spaces is about 1/2 of the thickness of the sub-screed, and therefore, the outer ends 2a and 3a of the sub-screeds 2 'and 3' are sub-screeds. And the thickness between the front and rear surfaces of the sub screed 2 '
The screed half portion engages with the notch portion 5 formed in the rear half portion of the other sub screed 3 'from the rear end inner end of the outer end portion 2a by the formation of the notch portion 4 in the rear half portion. 2b protrudes, and the notch 5 is formed in the front half of the other sub-screed 2 'from the inner end of the front half of the outer end 3a by forming the notch 5 in the front half of the other sub-screed 3'. 4 has a structure in which screed half portions 3b which are engaged with each other in a protruding state are provided, and these sub screeds 2 ', 3' are arranged symmetrically on the same axis in the left-right movable support frame. 8 and 9 respectively, these left and right sub screeds
When the screed halves 2a and 3a are completely engaged with the cutouts 4 and 5 by contracting 2 'and 3',
The width between the outer end surfaces 2 ′ and 3 ′ is configured to be equal to the width of the main screed 1.

Further, as shown in FIGS. 8 and 9, a side plate fixed to the outer end face of the sub screed 2 'is formed on the side of the sub screed 2' where the notch 4 is formed in the front half. 6, a pavement material scraping adjustment plate 14 is fixed to the front surface of the outer end 3a, and the adjustment plate 14 protrudes along the opening front end of the notch 4 so as to close the front opening of the notch 4. Let me. Further, in order to make the pavement thickness of the left and right sub screeds 2 'and 3' constant over the entire width, as shown in FIG. Screw means mounted on the inner surface of the outer plate 91 of the movable support frame 9 by separating the screed half 3b from the front half of the sub screed 3 'and pivotably and vertically pivotally attached to the rear end surface of the front half. The screed half 3b is configured to be vertically rotated by 18. These secondary screeds 2 ',
The structures of the movable support frames 8 and 9 that suspend the 3 'and other structures are the same as those in the above-described embodiment, and therefore, the same portions are denoted by the same reference numerals and detailed description thereof will be omitted.

Also in the screed device thus constructed, the movable support frames 8, 9 which suspend the left and right sub-screeds 2 ', 3' are respectively connected to the left and right two-stage hydraulic cylinders 10,
11 first-stage telescopic rods 10a, 11a and second-stage telescopic rod 10
By expanding and contracting b and 11b, a road having a width from the width of the main screed 1 to at least twice the width of the main screed 1 can be paved.

[0033]

As described above, according to the screed device of the paving machine of the present invention, the sub screed extending or contracting in the right or left direction from the main screed to the rear of the main screed provided at the lower rear end of the paving machine. The screed and the sub-screed that expands and contracts in the other direction are arranged in a state of being superimposed one on the other, so that when these sub-screeds are extended to the maximum, the overall width of the screed is at least twice the main screed. Because it is composed, both sub-screeds are arranged on the rear side of the main screed, so there is no need to install a leveling adjustment plate to adjust the feed amount of pavement material in front of the main screed. By moving the left and right sub-screeds in the direction of the pavement width along the rear part of the main screed, it is possible to obtain a pavement width twice or more that of the main screed, and The width adjustment work can be performed accurately and easily by simply adjusting the pair of sub-screeds up and down with respect to the main screed, improving work efficiency, and also having a simple structure and a small overall weight. Can be realized at low cost and practical use.

According to the second aspect of the present invention, the front half of one sub-screed and the rear half of the other sub-screed are formed with flat L-shaped notches which can be engaged with each other. When the two sub-screeds are contracted, the two sub-screeds can be smoothly and compactly stored at the rear side of the main screed while engaging with each other via the L-shaped cutout. As if the shape and size of one sub-screed were made, the structure of the entire screed device could be further simplified, and these sub-screeds along the rear surface of the main screed were symmetrically in the left-right direction on the same axis. Because it expands and contracts, the height adjustment of the iron part of both sub screeds with respect to the bottom part of the main screed, that is, the iron part that sets the pavement thickness to a constant thickness, can be performed easily and accurately. The workability is improved, and the pavement material discharged from the paving machine side to the front side of the screed is pressed to a certain thickness by the iron parts of the main screed and subsequently to the iron parts of these sub-screeds. This allows for efficient road pavement.

Further, according to the third aspect of the present invention, the main screed is attached to the lower end of the fixed support frame disposed at the rear end of the paving machine, and the auxiliary screed is provided at the lower end of the fixed support frame. The left and right movable support frames mounted are movably disposed in the left and right direction, and a pair of left and right fluid pressure cylinders are symmetrically disposed on the fixed support frame on a coaxial line. Since the frames are configured to extend and contract in the left-right direction, the auxiliary screed can be accurately and smoothly expanded and contracted in the pavement width direction with respect to the main screed with a simple mechanism.

[Brief description of the drawings]

FIG. 1 is a simplified perspective view of a screed device of the present invention;

FIG. 2 is a simplified rear view in which a part of a state in which a sub screed is contracted to a minimum width is shown in section.

FIG. 3 is a simplified plan view at that time,

FIG. 4 is a simplified rear view in which a part of a state in which a sub screed is contracted to a maximum width is shown in section.

FIG. 5 is a simplified plan view at that time,

FIG. 6 is a simplified side view of a paver equipped with a screed device,

FIG. 7 is a simplified perspective view of a screed device showing another embodiment of the present invention;

FIG. 8 is a simplified plan view showing a state in which the sub screed is contracted to a minimum width;

FIG. 9 is a simplified plan view showing a state in which a sub-screed is contracted to a maximum width.

[Explanation of symbols]

 A Paving machine 1 Main screed 2, 3 Secondary screed 2a, 3a Outer end 2b, 3b Screed half 4, 5 Notch 7 Fixed support frame 8, 9 Movable support frame 10, 11 Two-stage hydraulic cylinder

Claims (3)

[Claims] 1. A sub screed extending and contracting in one of left and right directions from a main screed and a sub screed extending and contracting in the other direction are provided at the rear of a main screed disposed at a lower rear end of a paver. When the width of these sub-screeds is formed to be at least half the width of the main screed and these sub-screeds are extended to the maximum extent, the entire width of the screed becomes equal to that of the main screed. A screed device for a paving machine, wherein the screed device is configured to be at least twice as large. 2. The two sub-screeds are disposed symmetrically at the rear of the main screed, and are flat on the front half of one sub-screed and the rear half of the other sub-screed from the inner end surface to the outer end. L-shaped notches are respectively formed, and the two sub-screeds are engaged with each other through these notches so that the width between the outer end faces of the two sub-screeds becomes a contraction width substantially equal to the width of the main screed. The screed device in a paving machine according to claim 1, characterized in that: 3. A left and right movable support frame having a main screed attached to a lower end of a fixed support frame portion provided at a rear end of the paving machine, and a sub screed attached to a lower end of the fixed support frame. And a pair of left and right fluid pressure cylinders are symmetrically arranged on the fixed support frame on the same axis, and the left and right movable support frames are expanded and contracted in the left and right directions by these fluid pressure cylinders. The screed device for a paving machine according to claim 1 or 2, wherein the screed device is configured to be moved.