JP6902494B2 - Screed device - Google Patents

Description

The present invention relates to a screed device.

Pavement vehicles such as asphalt finishers are equipped with a screed device that spreads and compacts the pavement material supplied to the construction surface. As this type of screed device, a so-called high compaction screed device having high compaction performance is known.

For example, in Patent Documents 1 and 2, a screed plate for spreading the pavement material, a tamper arranged in front of the screed plate and moving up and down to compact the pavement material, and a tamper arranged behind the screed plate to press the pavement material. A high compaction screed device with a pressure bar for compaction is disclosed.

The tip surface that presses the pavement material in the pressure bar is composed of a flat surface on the rear side and an inclined surface on the front side, and the inclined surface is inclined upward toward the front side. In the pressure bar, in order to increase the density (compacting degree) of the pavement material, an inclined surface is provided to reduce the contact area between the tip surface and the pavement material.

Japanese Unexamined Patent Publication No. 2012-225153 Japanese Unexamined Patent Publication No. 2001-11816

However, in the screed devices of Patent Documents 1 and 2, since the front side of the tip surface of the pressure bar is an inclined surface, fine cracks occur in the vehicle width direction when the pavement material is pushed by the pressure bar. There is a problem that the properties of the pavement surface deteriorate. In addition, since the pressure bar is provided with an inclined surface, a part of the pavement material stays in the space (gap) in front of the inclined surface or adheres to the inclined surface. Therefore, if the pavement vehicle moves forward in this state, it stays. There is a problem that the pavement surface is deteriorated due to the formation of streaks along the moving direction on the pavement surface due to the dragging of the attached pavement material.

The present invention has been devised from such a viewpoint, and an object of the present invention is to provide a screed device capable of satisfactorily finishing the properties of the pavement surface while appropriately increasing the density of the pavement material.

In order to solve the above problems, the screed device according to the present invention is a device mounted on a pavement vehicle to spread and compact the pavement material, and the screed plate for spreading the pavement material and the front of the screed plate. A tamper that moves up and down to compact the pavement material and a single pressure plate that is arranged behind the screed plate and presses and compacts the pavement material. The tip surface of the pressure plate comprises only a flat surface. The dimension of the tip surface of the pressure plate along the front-rear direction is preferably 10 cm or more.

According to the present invention, since the tip surface of a single pressure plate is composed of only a flat surface, it is possible to suppress the occurrence of fine cracks when the pavement material is pushed in. Further, since the tip surface of the pressure plate is composed of only a flat surface, it is possible to prevent the pavement material from staying or adhering to the tip surface of the pressure plate, and it is possible to suppress the generation of streaks. As a result, the properties of the pavement surface can be satisfactorily finished. Further, since the pavement material is compacted by the tampers and the pressure plate arranged before and after the screed plate, the density of the pavement material can be suitably increased.

Further, it is preferable that the pressure plate includes a channel material having a U-shaped cross section that extends in the vehicle width direction and opens upward. In this way, the structure of the pressure plate can be simplified.

Further, the pressure plate extends in the vehicle width direction, and is placed on the web, a web including the tip surface, a pair of front and rear flanges extending upward from both front and rear ends of the web, and the web. It is preferable to include a heating means extending in the vehicle width direction and a pair of front and rear L-shaped steels that sandwich the heating means from both front and rear sides. In this way, it is possible to prevent the heating means from moving in the front-rear direction. Further, by using the L-shaped steel, the structure for preventing the movement of the heating means in the front-rear direction can be simplified.

According to the screed device of the present invention, it is possible to satisfactorily finish the properties of the pavement surface while suitably increasing the density of the pavement material.

It is a side view which shows the asphalt finisher which concerns on embodiment of this invention. It is a partially enlarged view of FIG. 1 which shows the screed device which concerns on embodiment. It is a partially enlarged view of FIG. 2 which shows the pressure plate which concerns on embodiment. It is a partially enlarged view which shows the pressure plate which concerns on a modification.

Embodiments of the present invention will be described in detail with reference to the drawings as appropriate.
As shown in FIG. 1, the asphalt finisher A is used when paving a road surface such as a road, and has a predetermined thickness while advancing the pavement material (asphalt mixture) M supplied on the construction surface S. It is a paved vehicle that is spread evenly. The asphalt finisher A mainly includes a self-propelled vehicle body 1, a hopper 2, a screw spreader 3, and a screed device 4.

The vehicle body 1 includes a vehicle body frame, two pairs of left and right front wheels 1a, a pair of left and right rear wheels 1b, an engine room 1c, a driver's seat 1d, and the like. The vehicle body 1 travels on the construction surface S by driving the rear wheels 1b. The front wheel 1a is arranged below the hopper 2. The rear wheels 1b are arranged below the engine room 1c and the driver's seat 1d.

The hopper 2 is a member that receives and stores the pavement material M from a dump truck or the like arranged in front of the asphalt finisher A at the time of pavement construction. The hopper 2 is arranged at the front portion of the vehicle body 1. The hopper 2 is arranged in front of and below the engine room 1c and the driver's seat 1d. Although not shown, the vehicle body 1 is provided with a transport device such as a bar feeder that transports the pavement material M in the hopper 2 to the rear and supplies it onto the construction surface S. The carry-out end of the transport device is located in front of the screw spreader 3.

The screw spreader 3 is a device that spreads the pavement material M supplied on the construction surface S in the vehicle width direction. The screw spreader 3 is arranged behind the rear wheels 1b in the rear part of the vehicle body 1. The screw spreader 3 is arranged rearward and below the engine room 1c and the driver's seat 1d. The screw spreader 3 includes a screw extending in the vehicle width direction. The screws are rotatably arranged around an axis along the vehicle width direction.

The screed device 4 is a device for spreading and compacting the spread pavement material M. The screed device 4 is attached to a leveling arm 5 (only one of which is shown in FIG. 1) extending rearward from both side surfaces of the vehicle body 1, and is arranged further behind the screw spreader 3. The screed device 4 extends in the vehicle width direction. A step 6 for mounting the worker P is attached to the rear of the screed device 4. At the time of pavement construction, the worker P is placed on step 6 so that the thickness of the pavement material M can be confirmed.

The screed device 4 shown in FIG. 2 mainly includes a screed frame 4a, a screed plate 4b, a tamper 4c, and a pressure plate 4d. In addition, in FIG. 2 and FIG. 3, the pavement material M is omitted. The screed device 4 shown in FIGS. 1 to 3 is in a horizontal position for convenience of explanation, but in reality, the screed device 4 is laid out in a slightly tilted state so as to be tilted upward toward the front.

The screed frame 4a is a metal skeleton member that supports the screed plate 4b, the tamper 4c, and the pressure plate 4d, and extends in the vehicle width direction. The screed frame 4a is configured by combining a plurality of frame materials. The upper front portion of the screed frame 4a is attached to the leveling arm 5. When adjusting the leveling height of the pavement material M, the leveling arm 5 may be operated to adjust the height of the screed frame 4a.

The screed plate 4b is a bottom plate attached to the lower end of the screed frame 4a, and is a metal member on which the pavement material M is spread by weight (own weight). The screed plate 4b extends in the vehicle width direction and exhibits a rectangular flat plate shape that is long in the front-rear direction when viewed from the side. The screed plate 4b is fixed to the lower end of the screed frame 4a by a fixing means such as a bolt.

The tamper 4c is a device that is arranged in front of the screed plate 4b and moves up and down to compact the pavement material M. The tamper 4c includes one tamper bar 41a that moves up and down to press the pavement material M, an eccentric shaft 41b that serves as a rotation axis of the tamper bar 41a, an eccentric arm (not shown) that transmits the rotational force of the eccentric shaft 41b to the tamper bar 41a. It is composed of. The tamper bar 41a is a metal member extending in the vehicle width direction, and exhibits a substantially vertically long rectangular shape in a side view. The front end surface (lower end surface) of the tamper bar 41a is composed of a flat surface on the rear side and an inclined surface on the front side. The sloping surface slopes upward toward the front. The number of tamper bars 41a may be plural.

The pressure plate 4d is arranged behind the screed plate 4b and is a single device that presses and further compacts the pavement material M. The pressure plate 4d includes a plate main body 42 and a plate mounting member 43.

The plate body 42 is a single metal member that moves up and down to press the pavement material M, and exhibits a hollow rectangular cross section that is long in the front-rear direction when viewed from the side. The plate body 42 includes a plate lower 44 and a plate upper 45.

The plate lower 44 shown in FIG. 3 is located below and is a member constituting the lower wall, the front wall, and the rear wall of the plate main body 42. The configuration of the plate lower 44 is not particularly limited, but in the present embodiment, it is composed of a channel material having a U-shaped cross section that opens upward. The plate lower 44 includes a web 44a and a pair of front and rear flanges 44b, 44b. The lower surface of the web 44a constitutes _{the tip surface 4d 1} of the pressure plate 4d that presses the pavement material M. The tip surface 4d1 of the pressure plate 4d is composed of only a flat surface. The dimension L (also referred to as “web dimension L”) along the front-rear direction of the tip surface 4d1 of the pressure plate 4d is not particularly limited, but is preferably 10 cm or more. The front flange 44b extends upward from the front end of the web 44a. The rear flange 44b extends upward from the rear end of the web 44a.

The plate upper 45 is a member that closes the upper end opening of the plate lower 44 and constitutes the upper wall of the plate main body 42. The configuration of the plate upper 45 is not particularly limited, but in the present embodiment, it is made of flat steel. The plate upper 45 is fixed on the flanges 44b, 44b by welding or the like.

Inside the plate body 42, a heater rod 46, a front-rear movement prevention member 47, and an upper movement prevention member 48 are housed. The heater rod 46 is a heating means for heating the plate lower 44, and is mounted on the web 44a. The heater rod 46 extends in the vehicle width direction. The shape of the heater rod 46 is not particularly limited, but in the present embodiment, it exhibits a rectangular plate shape that is long in the front-rear direction when viewed from the side.

The front-rear movement prevention member 47 is a member that prevents the heater rod 46 from moving in the front-rear direction. The configuration of the front-rear movement prevention member 47 is not particularly limited, but in the present embodiment, it is made of a pair of L-shaped steels that sandwich the heater rod 46 from both front and rear sides. A pair of front and rear L-shaped steels are arranged so as to face each other with the heater rod 46 interposed therebetween. The front-back movement prevention member 47 is fixed on the web 44a by welding or the like. The front-rear movement prevention member 47 may support the entire range of the heater rod 46 in the vehicle width direction, or may support a part of the heater rod 46 in the vehicle width direction. The number of the front-back movement prevention members 47 may be one or a plurality.

The upper movement prevention member 48 is a member that prevents the heater rod 46 from moving upward. The configuration of the upper movement prevention member 48 is not particularly limited, but in the present embodiment, it is made of flat steel that presses the heater rod 46 from above. The front and rear ends of the upper movement prevention member 48 are fixed to the front and rear movement prevention member 47 by welding or the like, respectively. The upper movement prevention member 48 may press the entire range of the heater rod 46 in the vehicle width direction, or may press a part of the upper movement prevention member 48 in the vehicle width direction. The number of the upper movement prevention members 48 may be one or a plurality.

As shown in FIG. 2, the plate mounting member 43 is a metal fitting for mounting the plate body 42 to the screed frame 4a. The plate mounting member 43 extends in the vertical direction. The lower end of the plate mounting member 43 is fixed to the plate upper 45 by welding or the like. Although not shown, the pressure plate 4d uses a spring that urges the plate body 42 and the plate mounting member 43 upward, and the plate body 42 and the plate mounting member 43 that are hydraulically pressed downward against the urging force of the spring. It is equipped with a hydraulic mechanism. The plate body 42 pulsates (slightly vibrates) by alternately repeating downward movement due to the pressing force of the hydraulic mechanism and upward movement due to the urging force of the spring.

It is preferable that the plate body 42 and the existing pressure bar (see Patent Documents 1 and 2) are replaceable (removable) with respect to the plate mounting member 43, because they can be used properly according to the intended use. For example, for asphalt pavement or the like where high quality of the pavement surface is required, the pressure plate specification can be used, and for crushed stone ground pavement or the like where high quality of the pavement surface is not required, the pressure bar specification can be used properly.

In the pavement construction using the asphalt finisher A described above, first, the pavement material M introduced into the hopper 2 from a transportation means such as a dump truck is conveyed rearward by a transportation device such as a bar feeder and supplied onto the construction surface S. To do. Subsequently, the pavement material M supplied on the construction surface S is spread and spread to a predetermined leveling width by the screw spreader 3, and is spread and compacted to a predetermined thickness by the screed device 4. After that, the pavement body is constructed by rolling the pavement material M with a roller.

The asphalt finisher A according to the present embodiment is basically configured as described above. Next, the action and effect will be described.

According to the present embodiment, as shown in FIG. 2, since the tip surface 4d1 of the single pressure plate 4d is composed of only a flat surface, it is possible to suppress the occurrence of fine cracks when the pavement material M is pushed in. Further, since the tip surface 4d1 of the pressure plate 4d is composed of only a flat surface, it is possible to prevent the pavement material M from staying or adhering to the tip surface 4d1 of the pressure plate 4d, and it is possible to suppress the generation of streaks. As a result, the properties of the pavement surface can be satisfactorily finished.
Further, since the pavement material M is compacted by the tampers 4c and the pressure plate 4d arranged before and after the screed plate 4b, the density of the pavement material M can be suitably increased.

Further, since the density of the pavement material M can be suitably increased by the screed device 4, the number of rolling compactions of the rollers can be reduced. If the rolling compaction of the roller is delayed after leveling and compaction by the screed device 4, construction defects occur in which the density of the pavement material M and the fineness of the pavement surface become insufficient. However, in the present embodiment, the rolling compaction of the roller occurs. Since the number of times can be reduced, it is possible to suppress the occurrence of such construction defects and improve the certainty of construction quality.
Further, since the density of the pavement material M can be suitably increased by the screed device 4, the number of rollers normally used by two can be reduced to one. As a result, the construction work can be saved.

Further, according to the present embodiment, as shown in FIG. 3, the pressure plate 4d includes a plate lower 44 which is a channel material having a U-shaped cross section extending in the vehicle width direction and opening upward. The structure of the pressure plate 4d can be simplified.

Further, according to the present embodiment, as shown in FIG. 3, the pressure plate 4d is a pair of front and rear heater rods 46 that are placed on the web 44a and extend in the vehicle width direction and sandwich the heater rods 46 from both front and rear sides. It is provided with front-rear movement prevention members 47, 47 made of L-shaped steel. Therefore, it is possible to prevent the heater rod 46 from moving in the front-rear direction. Further, by using the L-shaped steel, the structure of the front-rear movement prevention member 47 can be simplified.

In pavement having a waterproof function such as crushed stone mastic asphalt pavement (SMA pavement) used for bridge surface pavement, the fineness of the pavement surface is particularly required. On the other hand, in the present embodiment, high precision can be expected to be obtained by applying a slight vibration of the pressure plate 4d to the pavement material M while pressing the pavement material M from above on the flat surface of the pressure plate 4d. As a result, it can be expected to meet the standards of precision required for SMA pavement and the like.

Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments and can be appropriately modified without departing from the spirit of the present invention.
In the present embodiment, the screed device 4 is mounted on the asphalt finisher A, but it may be mounted on a paved vehicle having a leveling function such as a repeater or a remixer, for example.
In the present embodiment, the plate main body 42 is divided into a plate lower 44 and a plate upper 45, but the plate main body 42 may be integrated. Further, the shape of the plate body 42 is not limited to that of the embodiment as long as the tip surface 4d1 is composed of only a flat surface.

As shown in FIG. 4, the front protruding corner portion 44c composed of the web 44a and the front flange 44b may be subjected to R chamfering. The radius of curvature of the front protruding corner portion 44c may be appropriately set as long as it does not hinder the action and effect of the present invention, and is preferably set to 1/5 or less of the web dimension L, for example. According to this modification, the pavement material M can be easily guided below the tip surface 4d1 of the pressure plate 4d.

A Asphalt finisher (paved vehicle)
M Pavement material 4 Screed device 4b Screed plate 4c Tampa 4d Pressure plate 4d1 Tip surface 42 Plate body 43 Plate mounting member 44 Plate lower (channel material)
44a Web 44b Flange 44c Front protruding corner 46 Heater rod (heating means)
47 Back and forth movement prevention member (L-shaped steel)
L Dimensions along the front-back direction of the tip surface

Claims (2)

A screed device that is mounted on a pavement vehicle to spread and compact the pavement material.
A screed plate that spreads the pavement material and
A tamper that is placed in front of the screed plate and moves up and down to compact the pavement material.
It comprises a single pressure plate, which is located behind the screed plate and presses and compacts the pavement material.
The distal end surface of the pressure plate, Ri consists only flat surfaces,
The pressure plate includes a plate body and a plate mounting member that attaches the plate body to a screed frame.
The plate body
A web including the tip surface and a pair of front and rear flanges extending upward from both front and rear ends of the web, and a channel material having a U-shaped cross section extending in the vehicle width direction and opening upward.
A heating means mounted on the web and extending in the vehicle width direction,
A pair of front and rear L-shaped steels that sandwich the heating means from both front and rear sides,
A plate upper that closes the opening of the channel material is provided.
The pressure plate includes a spring that urges the plate body and the plate mounting member upward, and a hydraulic mechanism that hydraulically presses the plate body and the plate mounting member downward against the urging force of the spring. A screed device characterized by being provided with. The screed device according to claim 1, wherein the dimension of the tip surface of the pressure plate along the front-rear direction is 10 cm or more.

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