JP7352960B2 - road paving machine - Google Patents

Description

TECHNICAL FIELD The present invention relates to a road paver, and more particularly to a road paver having a telescoping screed and having a feature of controlling the amount of mixed material conveyed.

In general, road paving work using a road paving machine called an asphalt finisher is performed by transferring asphalt mixture received in a hopper to the screw side by a bar feeder (also called a bar conveyor), as shown in Fig. 1 of Patent Document 1. While the main body is running, the screeding device at the rear level the composite material on the road surface to form a pavement.

When operating road paving machines, it is important to maintain a constant pavement thickness. In order to keep the pavement thickness constant, it is necessary to keep the amount of asphalt mixture held between the bar feeder and the screw constant. If the holding amount is small, the pavement thickness will be thin. If the amount of holding increases, the thickness of the pavement may increase. Therefore, it becomes impossible to construct pavement with a constant pavement thickness.

Furthermore, for example, in the case of a small road paving machine that can pave in narrow spaces, it is possible to widen or narrow the paving width by changing the width of the screed device. Such screed devices are well known as devices with telescopic screeds.

Utility Model Publication No. 4-92008 Utility Model Publication No. 3-36013 Publication number 62-5047 Special Publication No. 62-21925

In the case of a road paving machine having a telescopic screed, it is necessary to adjust the amount of holding according to the amount of expansion and contraction. For example, in the middle of paving, if you want to widen the pavement width, you must maintain an appropriate amount of retention to prevent the pavement thickness from becoming thinner. Therefore, conventionally, when widening the pavement width, the operator increases the rotation speed of the bar feeder to convey more asphalt mixture to the screw side, and then increases the rotation speed of the screw to increase the rotation speed of the bar feeder. Manual control was performed to ensure that there was no shortage of asphalt mix for the construction width.

This kind of control relies heavily on the operator's experience; if the telescopic screed is widened but the amount of holding is small or the screw rotation is slow, the ends of the expanded telescopic screed may be If the asphalt mixture cannot reach the edges, it may not be possible to pave the edges, or the thickness may not be sufficient.

Therefore, the present invention provides a road paving machine having a retractable screed, which enables paving work to be carried out with as little burden on the operator as possible through automatic control when changing the paving width. The purpose is to provide

Note that a comparative explanation will be given regarding Patent Documents 1 to 4 as follows.

Although the asphalt finisher described in Patent Document 1 is equipped with a pavement width sensor, there is no mention of the concept of automatically controlling the feed rate of the composite material when the pavement width is changed.

The asphalt finisher described in Patent Document 2 can control the amount of asphalt mixture conveyed by the feeder according to the input pavement width and thickness, and can change the amount of asphalt mixture conveyed in proportion to the vehicle speed. However, at actual construction sites, operators fine-tune the width of the retractable screed while observing the width of the road being constructed. Therefore, the asphalt described in Patent Document 2, which controls the conveyance amount of asphalt mixture based on the numerically input pavement width, is essentially different from the present invention.

The asphalt finishers of Patent Documents 3 and 4 are equipped with a screed expansion/contraction amount detection unit and adjust the amount of asphalt mixture by adjusting the opening/closing amount of the feeder gate. There is no disclosure whatsoever regarding the adjustment of the screw rotation speed or the control method after the judgment is completed.

In order to solve the above problems, the present invention has the following features. The present invention is a road paving machine that is equipped with an expandable screed, a bar feeder that conveys the mixture, and a screw that spreads the mixture, and includes expansion and contraction amount detection means for detecting the amount of expansion and contraction of the screed. , and a controller that controls the conveyance amount of the composite material by the bar feeder and the screw according to the amount of expansion and contraction detected by the amount of expansion and contraction detection means.

When the screed expands, the controller increases the speed of the bar feeder and the screw to add mixed material, and then operates the bar feeder and the screw at a conveyance amount corresponding to the expansion width.

When the screed is shrunk, the controller stops or decelerates the bar feeder and screw to adjust the amount of composite material, and then operates the bar feeder and screw at a conveyance amount corresponding to the shrunk width.

If the screed expands, the controller calculates the amount of material missing due to the expansion and increases the speed of the bar feeder and screw until the missing material is replenished.

The controller calculates the amount of mix material missing based on the expansion width and the retention dimension in front of the screed.

When the screed expands, the controller calculates the conveyance amount according to the expansion width and operates the bar feeder and screw based on the calculated conveyance amount.

The controller calculates the conveyance amount according to the expansion width based on the construction width, pavement thickness, and construction speed.

When the screed shrinks, the controller calculates the amount of surplus material due to the reduction and stops or slows down the bar feeder and screw until the surplus material is used.

The controller calculates the amount of surplus material based on the reduction width and the retention dimension in front of the screed.

When the screed is shrunk, the controller calculates the amount of conveyance according to the width of the reduction, and operates the bar feeder and screw based on the calculated amount of conveyance.

The controller calculates the conveyance amount according to the reduced width based on the construction width, pavement thickness, and construction speed.

The controller stores information about the initial construction conditions and controls the bar feeder and screed as the screed expands or contracts, based on, for example, what percentage of the initial construction conditions the bar feeder and screed should be sped up or down from. Control. In addition, the controller may control the rotation speed of the bar feeder and/or the screed by, for example, providing a detection means for the rotation speed of the bar feeder and/or the screed, a rotation speed control circuit, or the like.

If the screed expands, the controller increases the speed of the bar feeder and screw to replenish the missing mix material within engine tolerances.

It is a two-row type in which the screed is expandable and retractable to the left and right, bar feeders are present on the left and right, and the conveyance amount can be controlled separately on the left and right, and screws are present on the left and right, allowing the conveyance amount to be controlled separately on the left and right. If it is possible to control the right and/or left conveyance of the bar feeder and the right and/or left conveyance of the screw, the controller controls the right and/or left conveyance of the bar feeder, depending on the right and/or left expansion and contraction of the screed. Control quantity.

If the screed is expandable and retractable to the left and right, the bar feeder is a single thread type that cannot be controlled separately for the left and right, and screws are present on the left and right so that the conveyance amount can be controlled separately for the left and right, the controller will , the conveyance amount of the bar feeder and the right and/or left conveyance amount of the screw are controlled according to the amount of expansion and contraction of the right and/or left side of the screed.

The operator can input a correction value for the conveyance amount of the bar feeder and/or the screw, and the controller adjusts the conveyance amount of the bar feeder and/or the screw based on the correction value input by the operator.

The expansion/contraction amount detection means detects the amount of expansion/contraction of the screed based on the operating time of the expansion/contraction cylinder.

The expansion and contraction amount detection means detects the amount of expansion and contraction of the screed based on a sensor attached to the expansion cylinder or the screed.

According to the present invention, when the screed expands, the controller increases the speed of the bar feeder and the screw to add mixed material, and then operates the bar feeder and the screw with a conveyance amount that corresponds to the expansion width, so that the screed is expanded. In the case of reduction, the bar feeder and screw are stopped or decelerated to adjust the amount of mixed material, and then the bar feeder and screw are operated with the conveyance amount according to the reduction width, so in a road paving machine with a telescopic screed, When changing the pavement width, the paving work can be done as much as possible without putting a burden on the operator through automatic control.

The amount of material missing by expanding the screed is calculated, and the amount of material surplus is calculated by increasing the speed of the bar feeder and screw, or by reducing the screed, until the missing material is replenished. By stopping or slowing down the bar feeder and screw until the surplus material is used, the amount of conveyance can be automatically adjusted in response to changes in pavement width, reducing the burden on the operator. .

If the amount of insufficient material or the amount of surplus material is calculated based on the expanded width or reduced width and the holding dimension in front of the screed, control using simple calculations can be realized.

If the conveyance amount is calculated according to the expanded width or reduced width based on the construction width, pavement thickness, and construction speed, control using simple calculations can be realized.

The control of the bar feeder and screed becomes easier because the controller determines at what percentage the bar feeder and screed should be controlled by increasing the speed or, in principle, by what percentage compared to the initial construction state. Although such control is suitable for hydraulic circuits, it is not limited thereto. Further, by providing a means for detecting the rotation speed of the bar feeder and/or the screed, a rotation speed control circuit, etc., it becomes possible to accurately control the rotation speed of the bar feeder and/or the screed.

By increasing the speed of the bar feeder and screw, within the allowable range of the engine that lacks mix material, the mix can be fed as quickly as possible, so that the pavement thickness is as accurate as possible. Can be constructed.

The present invention realizes control compatible with single-row type and double-row type bar feeders, and is versatile.

If the operation time of the telescopic cylinder is used as the means for detecting the amount of expansion/contraction, there is no need to install a new sensor, so costs can be reduced.

If a telescopic cylinder or a sensor attached to the screed is used as the expansion/contraction detection means, the amount of expansion/contraction of the screed can be accurately detected.

These and other objects, features, aspects, and advantages of the present invention will become more apparent from the following detailed description when considered in conjunction with the accompanying drawings.

FIG. 1 is a schematic side view of a road paving machine 1 according to an embodiment of the present invention. FIG. 2 is a schematic plan view of a road paving machine 1 according to an embodiment of the present invention. FIG. 3 is a schematic system diagram showing the functional configuration of the road paving machine 1 according to an embodiment of the present invention. FIG. 4 is a flowchart showing an initial construction state grasping process executed in the controller 13 of the road paving machine 1 according to an embodiment of the present invention. FIG. 5 is a flowchart showing a process executed in the controller 13 of the road paving machine 1 according to an embodiment of the present invention when the screed extension switch is operated.

Hereinafter, the general structure, operation, and control method of a road paving machine 1 according to an embodiment of the present invention will be described with reference to FIGS. 1 to 5.

As shown in FIGS. 1 to 3, the road paving machine 1 includes a right bar feeder 2a, a left bar feeder 2b, a hydraulic motor 7a for the right bar feeder 2a, a hydraulic motor 7b for the left bar feeder 2b, Right screw 3a, left screw 3b, hydraulic motor 8a for right screw 3a, hydraulic motor 8b for left screw 3b, main screed 4, right rear wheel 5a, left rear wheel 5b, right rear wheel 5a, a hydraulic motor 6b for the left rear wheel 5b, a right telescopic screed 9a, a left telescopic screed 9b, a hydraulic cylinder 10a for the right telescopic screed 9a, and a hydraulic cylinder for the left telescopic screed 9b. 10b, engine 11, hydraulic pump 12, controller 13, operation panel 14, travel lever 15, hydraulic solenoid proportional valve and hydraulic solenoid valve 16, right hopper 19a, left hopper 19b, right hopper 19a. hydraulic cylinder 16a, hydraulic cylinder 16b for left hopper 19b, right front wheel 17a, left front wheel 17b, main step 18, right step 18a, left step 18b, handle 19, right leveling arm 20a. , a left leveling arm 20b, a hydraulic cylinder 21a for the right leveling arm 20a, and a hydraulic cylinder 21b for the left leveling arm 20b. Note that the hydraulic solenoid proportional valve and the hydraulic solenoid valve 16 may be of an integrated type or a separate type.

Note that each hydraulic motor and hydraulic cylinder is rotated or operated by high pressure oil discharged from a hydraulic pump 12 connected to the engine 11. The flow rate of the high-pressure oil is adjusted by controlling the hydraulic solenoid proportional valve and the hydraulic solenoid valve 16 in accordance with a command (output signal) from the controller 13. Thereby, the rotational speed of each hydraulic motor and the amount of expansion and contraction of the hydraulic cylinder are adjusted. In addition, although the road paving machine 1 is assumed to be driven by hydraulic pressure here, it may be driven by electric power, or may be driven by a combination of hydraulic pressure and electric power. Furthermore, the present invention is not limited to wheel-type road paving machines, but may also be applied to crawler-type road paving machines.

Here, just to be sure, the operation of the road paving machine 1 will be briefly explained. Asphalt mixture (hereinafter simply referred to as "mixture material") is stored in a hopper formed by the right hopper 19a and the left hopper 19b. The inclinations of the left and right hoppers 19a, 19b can be adjusted by hydraulic cylinders 16a, 16b. For example, as the amount of mixed material decreases, the inclination angles of the left and right hoppers 19a, 19b are adjusted to become larger. Then, the composite material is dropped onto the left and right bar feeders 2a, 2b.

The rotational speeds of the left and right bar feeders 2a, 2b can be adjusted by hydraulic motors 7a, 7b, respectively. The bar feeders 2a, 2b are provided at the bottom of the hoppers 19a, 19b, and convey the composite material contained in the hoppers to the front of the left and right screws 3a, 3b.

The left and right screws 3a and 3b are rotated by hydraulic motors 8a and 8b, respectively, and are configured, for example, in a spiral shape so as to spread the mixed material from the bar feeders 2a and 2b left and right. The shape is not limited.

For example, when the right telescopic screed 9a is extended, it is necessary to feed the mixture to the right side, so the rotation speed of the right bar feeder 2a is increased, the rotation speed of the right screw 3a is further increased, and the right telescopic screed is extended. The composite material will be sent to the 9a side.

The operation panel 14 is provided with switches or volumes for operating the rotational speed of the left and right bar feeders 2a, 2b, the rotational speed of the left and right screws 3a, 3b, and the expansion/contraction width of the left and right telescopic screeds 9a, 9b. .

The travel lever 15 is used to switch between forward and reverse travel. Further, the travel lever 15 exists to adjust the rotational speed of the hydraulic motors 6a, 6b of the left and right rear wheels 5a, 5b, and is used to adjust the travel speed of the road paving machine 1.

By adjusting the left and right leveling arms 20a, 20b by the left and right hydraulic cylinders 21a, 21b, the upward angle of the main screed 4 and the left and right telescopic screeds 9a, 9b is adjusted, and the pavement thickness is adjusted. Ru.

The operator operates the operation panel 14, travel lever 15, and handle 19 while riding on the main step 18 and the left and right right steps 18a and 18b to move to the front or lower part of the main screed 4 and the left and right telescopic screeds 9a and 9b. While checking the amount of mix material present, always being aware that the pavement is being constructed with the appropriate amount of mix material, and checking that the pavement thickness is appropriate, use the travel lever 15 to move the road. Construction is being carried out while moving the paving machine 1 forward.

Next, a control method by the controller 13 specific to the road paving machine 1 according to an embodiment of the present invention will be described.

As shown in FIG. 4, when the operator starts construction, the operator inputs the pavement thickness on the operation panel 14 (S10), and adjusts the expansion/contraction width with the expansion/contraction operation switch (SW) of the screed 9a and/or 9b (S20). ), adjust the feed rate of the composite material with the operating switch of the bar feeder 2a and/or 2b (S30), adjust the amount of diffusion of the composite material with the operating switch of the screw 3a and/or 3b (S40), Then, the traveling speed of the road paving machine 1 is adjusted (S50). The operations up to this point are basically manual operations based on the operator's experience and instructions during construction.

The controller 13 measures the operating time of the telescopic operation switch of the screed 9a and/or 9b (S21). The longer the operation time, the longer the pavement width. The controller 13 recognizes in advance the length of the pavement width according to the operation time using a storage table or a calculation formula, and calculates the pavement width according to the operation time (S22). Here, the pavement width is calculated according to the operation time, but the controller 13 uses various sensors to calculate the expansion and contraction of the expansion and contraction screed 9a and/or 9b or the left and right cylinders 10a and/or 10b. The pavement width may also be determined by determining the amount.

Note that the screed 9a and/or 9b may be extended only on one side, or may be extended on both sides by the same length or different lengths. In order to accommodate such various expansion/contraction widths, the controller 13 calculates how much each of the left and right screeds has expanded/contracted. For example, if the right telescopic screed 9a is extended by 10 cm and the left telescopic screed 9b is extended by 5 cm, it is recognized that the paving width has increased by 10 cm on the right side and 5 cm on the left side with respect to the paving width of the main screed 4. There is a need. The controller 13 needs to adjust the rotational speed of the left and right screws 3a and/or 3b depending on the amount of expansion and contraction of the left and right pavement widths.

Moreover, here, the rotational speeds of the left and right bar feeders 2a and/or 2b can be controlled separately using the right bar feeder 2a and the left bar feeder 2b. Therefore, the controller 13 also needs to adjust the rotational speed of the bar feeders 2a and/or 2b according to the amount of expansion and contraction of the left and right pavement widths.

Note that the number of rotations or the rotational speed of the bar feeder and the screw may be expressed as the amount of conveyance.

At the beginning of construction, the operator adjusts the rotation speed of the bar feeder 2a and/or 2b until a desired paving thickness is achieved. Once the desired pavement thickness is achieved, the operator stabilizes the rotational speed of the bar feeder 2a and/or 2b. The controller 13 recognizes that the rotational speed of the bar feeder 2a and/or 2b has stabilized, and measures the rotational speed of the bar feeder 2a and/or 2b at a stable time (S31). Then, the control roller 13 calculates the conveyance amount of the composite material according to the rotational speed of the bar feeder 2a and/or 2b (S32). Note that the controller 13 may determine whether the rotational speed of the bar feeder 2a and/or 2b has stabilized by determining whether or not the rotational speed remains within a certain range for a predetermined period of time, but other automatic control may also be used. Alternatively, an on/off switch may be provided so that the operator can manually instruct stabilization of the rotational speed, but the present invention is not limited thereto.

Note that there are two types of bar feeders: a two-row type and a single-row type. In the case of a two-row type, the rotational speed of the left and right bar feeders can be adjusted individually. In the case of a single-row type, it is not possible to differentiate the rotation speed between the left and right sides. Although this embodiment will be explained using a two-row type case, supplementary explanation will be given as appropriate regarding the one-line type case as well. Here, in the case of a single bar feeder, the controller 13 only needs to detect whether the rotational speed of the left and right integrated bar feeders is stable.

That is, in the initial construction state grasping process, when a two-row type bar feeder is used, the controller 13 calculates and stores the rotation speeds of the left and right bar feeders 2a and 2b. When a single-row bar feeder is used, the controller 13 calculates and stores the rotational speed of the single-row bar feeder.

At the beginning of construction, the operator adjusts the rotational speed of the screws 3a and/or 3b until a desired pavement thickness is achieved. Once the desired pavement thickness is achieved, the operator stabilizes the rotational speed of the screws 3a and/or 3b. The controller 13 recognizes that the rotational speed of the screws 3a and/or 3b has stabilized, and measures the rotational speed of the screws 3a and/or 3b at a stable time (S41). Then, the controller 13 calculates the number of rotations according to the rotational speed of the screws 3a and/or 3b (S42). Note that the controller 13 may determine whether the rotational speed of the screws 3a and/or 3b has stabilized by determining whether or not the rotational speed remains within a certain range for a predetermined period of time, but the invention is not limited thereto.

At the beginning of construction, the operator operates the hydraulic cylinder 21a for the right leveling arm 20a and the hydraulic cylinder 21b for the left leveling arm 20b, and adjusts the travel lever 15 as appropriate, until the desired pavement thickness is achieved. Once the desired pavement thickness is achieved, the operator stabilizes the travel lever 15. The controller 13 recognizes that the traveling speed determined by the traveling lever 15 has become stable, and measures the traveling speed at the time of stability (S51). The controller 13 then calculates the traveling speed (S52). Note that the controller 13 may determine whether the traveling speed has stabilized by determining whether the traveling speed remains within a certain range for a predetermined period of time, but the invention is not limited thereto.

Through the above operations, the pavement thickness (also referred to as construction thickness), pavement width (also referred to as construction width), bar feeder conveyance amount, screw rotation speed (conveyance amount), and running speed are determined as the initial construction state. The controller 13 stores this information (S60).

Here, information regarding the initial construction state stored in the controller 13 will be summarized.
<In the case of a two-row bar feeder>
Pavement thickness, overall pavement width, amount of expansion and contraction of the right telescopic screed 9a, amount of expansion and contraction of the left telescopic screed 9b, rotational speed of the right bar feeder 2a, rotational speed of the left bar feeder 2b, rotational speed of the right screw 3a, left screw 3b Rotational speed and running speed <For single-row bar feeder>
Pavement thickness, overall pavement width, amount of expansion and contraction of the right telescopic screed 9a, amount of expansion and contraction of the left telescopic screed 9b, rotational speed of the bar feeder, rotational speed of the right screw 3a, rotational speed of the left screw 3b, traveling speed

Note that the rotational speed of each bar feeder and the rotational speed of each screw can be replaced with the conveyance amount, and in the present invention, the conveyance amount refers to the actual conveyance amount of mixed material per unit time. , refers to rotational speed.

Note that the numerical values calculated and stored by the controller 13 in the initial construction state are merely examples, and the numerical values specifically calculated and stored are not limited to these. The information is not limited to the above information as long as it indicates the state at the time of initial construction.

Processing when the switch of the telescopic screed 9a and/or 9b is operated will be described with reference to FIG. 5. Again, it is assumed that both telescopic screeds 9a and/or 9b may be operated, or only one of them may be operated. Furthermore, it is assumed that the telescopic screeds 9a and/or 9b may have different lengths.

To roughly explain the operation of FIG. 5, the insufficient amount of mixed material or the excessive amount of mixed material is calculated based on how much the pavement width has increased or decreased, and the bar feeder 2a and By increasing, decreasing, or stopping the screws 2b and 3a and/or 3b, the mixture is automatically supplied to the screeding device in response to an increase or decrease in the pavement width.

First, when the switch of the telescopic screed 9a and/or 9b is operated (S101), in the case of a two-strip type, the controller 13 controls the left and right screeds based on the operating direction of the switch of the telescopic screed 9a and/or 9b. It is determined whether the image has been expanded or reduced (S102).

In the case of a single-row type, the controller 13 recognizes the expansion/contraction width of each left and right screed after operating the switch of the expansion/contraction screed 9a and/or 9b, and determines whether the overall pavement width has expanded or contracted. (S102). After the determination, as will be described later, in the case of the single-thread type, the conveyance amount of the left and right screws is controlled in the same way as the two-thread type.

In the case of a two-row type, for each of the telescopic screeds 9a and/or 9b, for the expanding telescopic screed side, proceed to step S201, and for the contracting telescopic screed side, proceed to step S301. move on. The operation of the telescopic screed, which has not changed, will be explained as appropriate.

In the case of the single-row type, if the overall pavement width is increasing, the process proceeds to step S201, and if the overall pavement width is decreasing, the process proceeds to step S301. In the case of the single-line system, operations that cannot be completely described in the flowchart shown in FIG. 5 will be explained as appropriate.

First, the operation in the two-line type will be explained, and then the operation in the one-line type will be explained.

In the case of the two-row type, in S201, the controller 13 measures the operation time of the switch of the extended telescopic screed 9a and/or 9b. Then, the controller 13 calculates the overall pavement width, the extension amount (stretched amount) of the right telescopic screed 9a, and/or the extension amount of the left telescopic screed 9b based on the operation time (S202).

Note that the above control based on the operation time by the controller 13 is based on the premise that the absolute positional relationship between the telescopic screeds 9a and 9b is not grasped by the sensor; If the absolute positional relationship can be grasped with the sensor attached to the screed 10b, the above calculation based on the operation time can be omitted, and based on the absolute positional relationship of the telescopic screeds 9a and 9b, the controller 13 The amount of expansion and contraction can be recognized. Therefore, the operations in S201 and S202 can be replaced with detection of the amount of expansion and contraction using a sensor.

That is, the road paving machine 1 according to the embodiment of the present invention is equipped with means for detecting the amount of expansion and contraction of the screed after being changed in accordance with the expansion and contraction operation of the screed. Note that changes in the amount of expansion and contraction of the screed can also be interpreted as changes in pavement width.

On the premise that the screed extension operation has been performed as described above, the controller 13 proceeds to the operation of S203.

In S203, the controller 13 calculates the amount of mixed material that is insufficient due to the increase in the pavement width. Although various calculation methods can be considered, one example will be introduced here.

The controller 13 calculates the amount of composite material required per unit time (for example, 1 minute) in the initial construction state. The controller 13 calculates the amount of additional mix required due to the increased pavement width.

For example, assume that the initial construction state is a pavement width of 3 m, a pavement thickness of 5 cm, and a running speed of 3 m/min. The dimensions assumed for the screed device of the road paving machine 1 are that the width of the main screed 4 is 1.5 m, the maximum amount of expansion and contraction of the right telescoping screed 9a is 1.25 m, and the maximum amount of expansion and contraction of the left telescoping screed 9b is 1.25 m. It is said that it is. In the initial construction state, the right telescopic screed has extended by 0.75 m, and the left telescopic screed has extended by 0.75 m, resulting in a pavement width of 1.5 + 0.75 + 0.75 = 3 m.

When a two-row bar feeder is used, it is assumed here that the mixture is uniformly supplied from the left and right bar feeders 2a and 2b to a pavement width of 3 m. In this case, the amount of mixed material per minute to be fed from the bar feeder on one side is 1.5 (m) x 0.05 (m) x 3 (m) = 0.225 (cubic meter). Therefore, the amount of mixed material per minute to be fed from the bar feeders 2a and 2b on both sides is 0.225 (cubic meters) x 2 = 0.45 (cubic meters). By the way, assuming that the maximum conveyance amount per minute by both bar feeders 2a and 2b is 2.36 (cubic meters), in this initial state, the bar feed rate is 0.45÷2.36=about 19%. The feeders 2a and 2b are conveying the composite material.

In this initial state, either the right telescopic screed 9a or the left telescopic screed 9b has been extended by 50 cm, that is, the screed width (pavement width) on one side has been extended by 50 cm. In addition, it is possible that the telescopic screeds 9a and 9b on both sides extend by the same or different amounts, but in that case, the amount of composite material required for each side must be calculated and the rotational speed of the bar feeder and screw for each side must be determined. We will have to calculate it.

If the screed stretches, the required information should include the size of the material to be held in front of the screed. Here, it is assumed that the front holding dimensions of the screed are, for example, 40 cm in width and 40 cm in height. Here, the width and height correspond to the diameters of the screws 3a and 3b when viewed from the front in FIG. 1, but are not limited thereto.

If the pavement width on one side increases by 50 cm, an additional volume of material corresponding to the holding dimension in front of the screed and an amount of material for the increased pavement width will be required. Therefore, 0.4 (m) x 0.4 (m) x 0.5 (m) = 0.08 (cubic meter) of additional material is required.

As described above, in the operation of S203, the controller 13 calculates the insufficient amount of composite material. The above calculation formulas and numerical values are merely an example for understanding the invention, and within the range of design that can be normally achieved by a person skilled in the art, taking into consideration the size and performance of the road paving machine 1. Naturally, the present invention should not be construed in a limited manner, since the controller 13 can be programmed to determine the calculation method as appropriate and calculate the insufficient amount of mixed material.

Next, the control by the controller 13 after calculating the insufficient amount of composite material will be explained. The controller 13 increases the speed of the bar feeders 2a and 2b within the engine permissible range (S204). This means that the bar feeders 2a and 2b are rotated at the maximum speed within the engine allowable range, and is an operation for conveying the insufficient mixture to the screw side as quickly as possible. However, the present invention is not limited to rotating the bar feeders 2a and 2b at the maximum speed within the engine allowable range, but simply increasing the speed of the bar feeders 2a and 2b to rotate as much as possible. What is necessary is to convey the insufficient composite material to the screw side.

Note that the rotational speeds of the bar feeders 2a and 2b may be changed depending on the width of expansion and contraction of the left and right screeds. For example, if only the right telescopic screed 9a is extended, only the right bar feeder 2a may be increased in speed. Further, the rotational speeds of the left and right bar feeders 2a and 2b may be increased by providing a difference in rotational speed.

As an example, consider a case in which the bar feeders 2a and 2b are able to transport composite material at a rate of 0.45 (cubic meters) per minute in the initial construction state. In this case, it is assumed that the maximum conveyance amount by the bar feeders 2a and 2b within the engine allowable range is 2.36 (cubic meters) per minute. At this time, it is assumed that only the right telescopic screed 9a has been extended by 50 cm, making it necessary to add 0.08 (cubic meters) of composite material.

If the speed of only the right bar feeder 2a is increased, the maximum transport amount per minute of the right bar feeder 2a is 1.18 (cubic meters), which is half of 2.36 (cubic meters). In the initial construction state, the left and right bar feeders 2a and 2b are used to transport 0.45 (cubic meters) of composite material per minute, so if only the right bar feeder 2a is used, half of that is 0.45 (cubic meters). 225 (cubic meters) is the transport amount per minute. Therefore, 0.955 (cubic meters), which is obtained by subtracting 0.225 (cubic meters) from the maximum conveyance amount of 1.18 (cubic meters) of the right bar feeder 2a, is the remaining capacity for the conveyance amount per minute that the right bar feeder 2a has. becomes.

Therefore, in order to convey an additional 0.08 (cubic meters) of mixed material, only the right bar feeder 2a needs to be accelerated for 0.08 ÷ (0.995 ÷ 60) = 5.0 (seconds). I know it's good.

It goes without saying that the operator may correct the speed increase time in S204 as appropriate based on the operator's experience.

At the same time, the controller 13 increases the speed of the screws 3a and/or 3b within the engine permissible range (S205). This means that the screws 3a and 3b are rotated at the maximum speed within the allowable range of the engine, and is an operation for conveying the insufficient material to the screed side as quickly as possible. However, in the present invention, the screws 3a and 3b are not limited to rotating at the maximum speed within the engine allowable range, but simply increasing the speed of the screws 3a and 3b to reduce the shortage as much as possible. It is sufficient to transport the composite material to the screw side.

Note that the rotational speeds of the screws 3a and 3b may be changed depending on the width of expansion and contraction of the left and right screeds. For example, if only the right telescopic screed 9a is extended, only the right screw 3a may be increased in speed. Further, the rotational speeds of the left and right screws 3a and 3b may be increased so as to have a difference in rotational speed.

Consider an example. As in the above example, it is assumed that the current conveyance rate of one bar feeder is 0.225 (cubic meters) per minute. Here, it is assumed that the maximum transport amount per minute of the screw on one side is 0.75 (cubic meters) per minute. In such a case, from 0.225÷0.75=0.3, it can be seen that the screw on one side should be operated at a rotational speed of 30%. In this case, it is assumed that the screed on one side is expanded by 50 cm and, as mentioned above, 0.08 (cubic meters) more is transported from the bar feeder.

The screw on one side is currently conveying at a rate of 0.225 (cubic meters) per minute, so subtract 0.225 (cubic meters) from the maximum conveyance per minute of the screw, 0.75 (cubic meters). It can be said that 0.525 (cubic meters) per minute is the remaining conveyance force by the screw.

Therefore, in order to convey an increased amount of 0.08 (cubic meters), it is sufficient to increase the speed of the screw on one side for a period of 0.08 ÷ (0.525 ÷ 60) = approximately 9.1 (seconds). I understand.

Note that the above calculation example is just an example, and those skilled in the art can program the controller 13 to calculate the speed increase time of the bar feeder and screw using an appropriate calculation method based on their experience and knowledge. It's good to do that.

It goes without saying that the operator may correct the speed increase time in S205 as appropriate based on the operator's experience.

After increasing the speed, the controller 13 determines whether the addition of the insufficient amount of mixed material has been completed (S206). Various judgments can be considered for this purpose. For example, it is possible to determine whether or not the addition of the insufficient amount of mixed material has been completed by determining the conveyance amount based on the time during which the bar feeders 2a and 2b or the screws 3a and 3b were accelerated.

Although the calculation is simplified here, there is of course a hydraulic response time, so the time to increase the speed of the bar feeder and screw may be calculated by taking such response time into consideration. Needless to say.

Alternatively, the amount of the mixture that has passed through the outlet of the bar feeder may be recognized using a sensor, image recognition, or the like, and it may be determined whether or not the addition of the insufficient mixture has been completed.

Next, the controller 13 operates the bar feeders 2a and 2b and the screws 3a and 3b with a conveying amount and a spreading amount commensurate with the increased pavement width (S207). In S207, the conveyance amount according to the expansion width is calculated.

An example of how to calculate the conveyance amount commensurate with the increased pavement width will be described below. For example, if only the right bar feeder 2a is extended and the construction width increases from 3 m to 3.5 m, and if the pavement thickness is 5 cm and the construction speed is 3 m/min, then , the amount of composite material required per minute is 2.0 (m) x 0.05 (m) x 3 = 0.3 (cubic meter). Note that 2.0 (m) is 0.75 (m), which is half of 1.5 (m), which is the width of the main screed 4, and 0.75 (m), which is the original extension of the right telescopic screed 9a. ) and the extended value of 0.5 (m).

If the maximum conveyance per minute of both bar feeders 2a and 2b is 2.36 (cubic meters), the maximum conveyance of the right bar feeder 2a is half, 1.18 (cubic meters). Therefore, 0.3 (cubic meter) is 0.3÷1.18=about 25%. Therefore, when conveying at 19% in the initial construction state, it is necessary to increase the speed by 25-19=6%. Therefore, in such an example, the controller 13 instructs the right bar feeder 2a to increase its speed by 6% and operates it.

Note that the left bar feeder 2b may operate with the original command value without increasing the speed. Here, the original command value for the left bar feeder 2b is 1.5 (m) x 0.05 (m) x 3 = 0.225 cubic meters/min, which is 19% of the maximum conveyance amount.

Note that the left and right telescopic screeds 9a and/or 9b may expand and contract with different expansion and contraction widths, but in this case as well, the amount of speed increase of each bar feeder will vary depending on the expansion and contraction width of the right or left screed. All you have to do is decide. That is, in the above example, the amount of expansion and contraction of the left telescoping screed 9b is only 0 cm, and if the left telescoping screed 9b were to extend by 30 cm, the required amount on the left side would be the same as when the right telescoping screed 9a was extended by 50 cm. The amount of mixed material per minute may be calculated, and the amount of increase in the rotational speed of the left bar feeder 2b may be determined by comparing it with the initial construction state.

In the case of a two-row type, if one screed is extended and the other screed is contracted, the bar feeder and screws on the extended screed side perform the operations from S201 onwards, and the bar feeder and screws on the shrunken screed side are , the operations after S301 will be performed.

The speed of the screws 3a and/or 3b may be increased by the same amount of speed increase as that of the bar feeders 2a and/or 2b. However, the controller 13 may calculate the speed increase amount of the screws 3a and/or 3b according to the speed increase amount of the bar feeders 2a and/or 2b, taking into account the performance of the screws and the like.

For example, a method of calculating the speed increase amount of the screws 3a and/or 3b as follows will be shown here as an example. When the construction width is 3.5 m, the pavement thickness is 5 cm, and the construction speed is 3 m/min, the material required for the right screw 3a is 2.5 m/min, similar to the material required for the right bar feeder 2a. 0 x 0.05 x 3 = 0.3 (cubic meter). If the maximum conveyance per minute of the screw on one side is 0.75 (cubic meters) per minute, then from 0.3 ÷ 0.75 = 0.4, the screw 3a on the right side has a , it can be seen that it is sufficient to rotate at a rotation speed of 40%. As already explained, the original command value for the screw was 30%, so in this case, the screw 3a only needs to increase its speed by 10%. The left screw 3b may be operated at the original command value (30%).

In this way, the bar feeder 2a and/or 2b and the screw 3a and/or 3b will operate with command values commensurate with the increased pavement width, but if the operator issues a correction command, The controller corrects the bar feeder transport amount and the screw rotation speed, and operates the bar feeder 2a and/or 2b and the screw 3a and/or 3b (S208).

Next, the operations after S301 will be explained. In the case of the two-row type, in S301, the controller 13 measures the operation time of the switch of the contracted telescopic screed 9a and/or 9b. Then, the controller 13 calculates the overall pavement width, the amount of reduction (shrinkage amount) of the right telescopic screed 9a, and/or the amount of reduction (shrinkage amount) of the left telescoping screed 9b based on the operation time ( S302).

Note that, similarly to S202, the road paving machine 1 may be considered to include means for detecting the changed amount of expansion/contraction in response to the expansion/contraction operation of the screed. Note that changes in the amount of expansion and contraction of the screed can also be interpreted as changes in pavement width.

Then, if the screed is being reduced, the controller 13 calculates the amount of excess material (S303). Although various calculation methods can be considered, one example will be introduced here.

It is assumed that the conditions in the initial construction state are the same as those described in S203. At this time, if the right telescopic screed 9a is shortened by 30 cm, as already explained, the volume corresponding to the front holding dimension of the screed will be 0.4 (m) x 0.4 (m). ) x 0.3 (m) = approximately 0.05 (cubic meter) of composite material is in excess.

As described above, in the operation of S303, the controller 13 calculates the amount of excess material. The above calculation formulas and numerical values are merely an example for understanding the invention, and within the range of design that can be normally achieved by a person skilled in the art, taking into consideration the size and performance of the road paving machine 1. Naturally, the present invention is not to be construed in a limited manner, since the controller 13 can be programmed to determine the calculation method as appropriate and calculate the amount of excess material.

Next, the control by the controller 13 after calculating the excessive amount of mixed material will be explained. The controller 13 stops the bar feeders 2a and 2b (S304). This is an operation to stop conveying the excess material to the screw side as quickly as possible by stopping the bar feeders 2a and 2b. However, in the present invention, the bar feeders 2a and 2b may be simply slowed down to avoid conveying excess material to the screw side as much as possible.

Note that the rotational speed of the bar feeders 2a and 2b may be reduced or stopped depending on the width of expansion and contraction of the left and right screeds. For example, if only the right telescopic screed 9a contracts, only the right bar feeder 2a may be decelerated or stopped. Further, the rotational speeds of the left and right bar feeders 2a and 2b may be decelerated by providing a difference in rotational speed.

Next, an example of how much to stop the bar feeder will be explained. As mentioned above, in the initial construction state, it is assumed that the right bar feeder 2a alone has a conveyance rate of 0.225 (cubic meters) per minute.

Therefore, if it is desired to stop 0.05 (cubic meters) of mixed material, it is sufficient to stop the right bar feeder 2a for approximately 13.3 seconds (0.05/(0.225/60)). At this time, the left bar feeder 2b is rotating in the initial construction state.

It goes without saying that the operator may correct the stopping time in S304 as appropriate based on the operator's experience.

At the same time, the controller 13 stops the screws 3a and/or 3b (S305). The stop time here may be the same as the stop time at the bar feeder 2a and/or 2b in S304, or the stop time may be calculated after calculating the stop time using the calculation example shown below. .

Consider an example of the stop time of the screws 3a and/or 3b. As in the above example, it is assumed that the current conveyance rate of one bar feeder is 0.225 (cubic meters) per minute. Here, it is assumed that the maximum transport amount per minute of the screw on one side is 0.75 (cubic meters) per minute. In such a case, from 0.225÷0.75=0.3, it can be seen that the screw on one side should be operated at a rotational speed of 30%. If the right screed is shrunk by 30 cm, as mentioned above, there will be an excess of 0.05 (cubic meters) of mix material.

It can be seen that it is sufficient to stop the screw on one side for approximately 13.3 seconds (0.05 (cubic meter) ÷ (0.225 ÷ 60)).

Similarly, it goes without saying that the operator may correct the stopping time in S305 as appropriate based on the operator's experience.

After the stop, the controller 13 determines whether the excessive amount of mixed material has disappeared and the adjustment to the appropriate amount of mixed material has been completed (S306). Various judgments can be considered for this purpose. For example, it can be determined whether the adjustment to the appropriate amount of mixed material has been completed based on the time during which the bar feeders 2a and 2b or the screws 3a and 3b are stopped.

Alternatively, the controller 13 may use a sensor, image recognition, or the like to determine whether adjustment to an appropriate amount of mixed material has been completed.

Note that although the calculations are simplified here, there is of course a hydraulic response time, so the time to stop the bar feeder and screw may be calculated taking such response time into account. Needless to say.

Next, the controller 13 operates the bar feeders 2a and 2b and the screws 3a and 3b with a conveying amount and a spreading amount commensurate with the reduced pavement width (S307). In S307, the conveyance amount according to the reduction width is calculated.

An example of how to calculate the conveyance amount commensurate with the reduced pavement width will be described below. For example, if only the right bar feeder 2a is shrunk and the construction width is reduced from 3 m to 2.7 m, and if the pavement thickness is 5 cm and the construction speed is 3 m/min, then , the amount of composite material required per minute is 1.2 (m) x 0.05 (m) x 3 = 0.18 (cubic meter). Note that 1.2 (m) is 0.75 (m), which is half of the width of the main screed 4 (1.5 (m)), and 0.75 (m), which is the original extension of the right telescopic screed 9a. It is the value obtained by subtracting the contracted value of 0.3 (m) from .

If the maximum conveyance per minute of both bar feeders 2a and 2b is 2.36 (cubic meters), the maximum conveyance of the right bar feeder 2a is half, 1.18 (cubic meters). Therefore, 0.18 (cubic meter) is 0.18÷1.18=about 15%. Therefore, when conveying at 19% in the initial construction state, 15-19=-4%, which means that a 4% deceleration is required. Therefore, in such an example, the controller 13 instructs the right bar feeder 2a to decelerate by 4% and operates it. Note that the left bar feeder 2b may operate with the original command value (0.225 cubic meters/min: 19%).

Note that the left and right bar feeders 2a and/or 2b may expand and contract with different expansion and contraction widths, but in this case as well, the amount of deceleration of each bar feeder is determined according to the expansion and contraction width of the right or left screed. All you have to do is decide. That is, in the above example, the amount of expansion and contraction of the left telescopic screed 9b is only 0 cm, and if the left telescopic screed 9b is shrunk by 10 cm and the right telescopic screed 9a is shrunk by 20 cm, then the left and right telescopic screeds 9b will shrink by 20 cm. What is necessary is to calculate the amount of mixed material and determine the amount of deceleration of the rotational speed of the left and right bar feeders 2a and 2b by comparing with the initial construction state.

The screws 3a and/or 3b may be decelerated by the same deceleration amount as the deceleration amount of the bar feeder 2a and/or 2b. However, the controller 13 may calculate the amount of deceleration of the screws 3a and/or 3b according to the amount of deceleration of the bar feeders 2a and/or 2b, taking into consideration the performance of the screws and the like.

Consider an example. As mentioned above, in this case the bar feeder is rotating at 0.18 cubic meters/min. The maximum conveyance of the screw is 0.75 cubic meters per minute, so 0.18÷0.75=0.24, and the screw rotates at a rotation speed of 24% of the maximum conveyance of the reduced screw. I know what I need to do is let it happen. In other words, since 24-30=-6, it is sufficient to reduce the speed of the reduced screw by 6%.

Regarding the screw that is not expanded or contracted, the conveyance amount of the bar feeder that is not expanded or contracted is 0.225 cubic meters/min, so 0.225 ÷ 0.75 = 0.3, and the original command value ( 30%).

In this way, the bar feeder 2a and/or 2b and the screw 3a and/or 3b will operate with command values commensurate with the reduced pavement width, but if the operator issues a correction command, The controller corrects the bar feeder transport amount and the screw rotation speed, and operates the bar feeder 2a and/or 2b and the screw 3a and/or 3b (S208).

Here, an example of calculation for a single bar feeder will be explained. Unlike the two-row type, in the case of the single-row type, the bar feeder cannot be rotated individually on the left and right sides, but the screw can be rotated on the left and right sides individually. Therefore, in the case of the two-row method, the differences from the calculation example described above are generally as follows.
(1) Bar feeder acceleration time and acceleration speed when only one screed is extended (2) Bar feeder deceleration time and deceleration speed when only one screed is shortened (3) One screed is extended In the case of (1), it is determined that the entire pavement width has been expanded in step S101. The process advances to operations after S201.
In the case of (2), it is determined in step S101 that the entire pavement width has been reduced, and the process proceeds to steps S301 and subsequent steps.
In the case of (3), in step S101, expansion or contraction of the entire pavement width is determined according to the amount of expansion and contraction of the left and right screeds, and the process proceeds to step S201 or S301.

Below, in the case of a single-row type, (1) the right screed is extended by 50 cm, (2) the right screed is shortened by 30 cm, (3) the right screed is shortened by 30 cm, and the left screed is shortened by 50 cm. An example of calculation will be explained for the case of stretching. Assume that construction is underway with a construction width of 3 m, a pavement thickness of 5 cm, and a construction speed of 3 m/min. In this case, 3.0 x 0.05 x 3 = 0.45 cubic meters/min, so if the maximum conveyance amount of the bar feeder on both sides is 2.36 cubic meters/min, then 0.45 ÷ 2. Since 36=approximately 0.19, the bar feeder is rotating at 19% of the maximum conveyance amount.

(1) When the right side screed is extended by 50 cm in a single-row type (when proceeding to operations after S201)
It is necessary to add 0.4 x 0.4 x 0.5 = 0.08 cubic meters of composite material on the right side. The bar feeder currently has a surplus conveying capacity of 2.36-0.45=1.91 cubic meters/min. Therefore, the speed should be increased for approximately 2.5 seconds (0.08/(1.91/60)). Note that the operator may be able to correct the speed increase time.

In the case of a construction width of 3.5 m, a pavement thickness of 5 cm, and a construction speed of 3 m/min, a bar feeder needs to transport the material at a rate of 3.5 x 0.05 x 3 = 0.525 cubic meters/min. That is, it is necessary to carry the material at approximately 22% (=0.525÷2.36) of the maximum carrying amount of the bar feeder. Therefore, if the bar feeder is being conveyed at 19%, it is sufficient to increase the speed of the bar feeder by 3%.

The speed increase time and stop time of the screw are the same as in the case of the two-thread type.

(2) When the right screed is shortened by 30 cm using a single-row method (when proceeding to operations after S301)
There is an excess of 0.4 x 0.4 x 0.3 = 0.05 cubic meters of composite material on the right side. Then, the bar feeder may be stopped for approximately 13.3 seconds (0.05÷(0.225÷60)). Note that the operator may be able to correct the speed increase time.

In the case of a construction width of 2.7 m, a pavement thickness of 5 cm, and a construction speed of 3 m/min, a bar feeder needs to transport the material at a rate of 2.7 x 0.05 x 3 = 0.405 cubic meters/min. That is, it is necessary to carry the material at a rate of approximately 17% (0.405÷2.36) of the maximum carrying amount of the bar feeder. Therefore, if the bar feeder is being conveyed at 19%, it is sufficient to decelerate the bar feeder by 2%.

The speed increase time and stop time of the screw are the same as in the case of the two-thread type.

(3) When the right screed is shortened by 30 cm and the left screed is extended by 50 cm in a single-row system (when proceeding to operations after S201)
There is an excess of 0.4 x 0.4 x 0.3 = 0.05 cubic meters of composite material on the right side. It is necessary to add 0.4 x 0.4 x 0.5 = 0.08 cubic meters of composite material on the left side. A total of 0.08-0.05=0.03 cubic meters of composite material is required.

Therefore, the bar feeder speed increase time is
2.36-0.45=1.91 cubic meters 0.03÷(1.91÷60)=1.0 seconds Therefore, it is 1.0 seconds.
Note that the operator may correct the speed increase time.

In this case, the construction width is 3.2 m, the pavement thickness is 5 cm, and the construction speed is 3 m/min, so it is necessary to transport the bar feeder at a rate of 3.2 x 0.05 x 3 = 0.48 cubic meters/min. This requires transport at approximately 20% (=0.48÷2.36) of the maximum transport amount of the bar feeder. Therefore, if the bar feeder is being conveyed at 9%, it is sufficient to increase the speed of the bar feeder by 1%.

Regarding the speed increase time and stop time of the screw, the command value of the screw when the screw is shortened by 30 cm on one side is the same as the command value of the screw when the screw is extended by 50 cm on one side.

In addition, in the case of a single-row type, if the overall size has shrunk, such as when the right side is shortened by 50 cm and the left side is widened by 30 cm, proceed to the operations after S301 and calculate the amount of surplus material. , the stop time of the bar feeder may be determined, and the deceleration command value after stopping the bar feeder may be determined.

Note that the correction value of the conveyance amount of the bar feeder and/or screw by the operator may be an absolute value or may be a correction value based on a percentage, and is not particularly limited. The road paving machine 1 includes an input unit for inputting correction values by the operator, and the controller 13 adjusts the conveyance amount of the bar feeder and/or the screw based on the correction values by the operator.

Note that if the screed expands or contracts and the construction width is changed from the initial construction state, the controller 13 updates the initial construction state to use the changed construction width.

Note that the pavement thickness may be measured by a sensor.

In the above embodiment, the controller stores information regarding the initial construction state, and when the screed expands or contracts, based on what percentage the speed should be increased or decelerated from the initial construction state, Although the bar feeder and the screed are controlled, the controller is not limited to this. For example, by providing a means for detecting the rotation speed of the bar feeder and/or the screed, a rotation speed control circuit, etc. The rotation speed of the feeder and/or the screed may be controlled. This makes it possible to accurately control the rotational speed of the bar feeder and/or the screed.

Although the above embodiment is based on a screed that expands and contracts from side to side, a road paving machine equipped with a screed that expands and contracts only on one side can also be used with bar feeders and screws in the same manner as in the above embodiment. It is possible to control the conveyance amount of the composite material.

Although the present invention has been described in detail above, the above description is merely an illustration of the present invention in all respects, and is not intended to limit the scope thereof. It goes without saying that various improvements and modifications can be made without departing from the scope of the invention. The constituent elements of the invention disclosed in this specification shall each be established as an independent invention. Inventions in which each component is combined in any combination method are also included in the present invention.

The present invention is a road paving machine and can be used industrially.

1 Road paving machine 2a Right bar feeder 2b Left bar feeder 3a Right screw 3b Left screw 4 Main screed 5a Right rear wheel 5b Left rear wheel 6a Hydraulic motor for right rear wheel 5a 6b Hydraulic motor for left rear wheel 5b 7a Right bar Hydraulic motor for feeder 2a 7b Hydraulic motor for left bar feeder 2b 8a Hydraulic motor for right screw 3a 8b Hydraulic motor for left screw 3b 9a Right telescopic screed 9b Left telescopic screed 10a Hydraulic cylinder for right telescopic screed 9a 10b Left Hydraulic cylinder for telescopic screed 9b 11 Engine 12 Hydraulic pump 13 Controller 14 Operation panel 15 Travel lever 16 Hydraulic solenoid proportional valve and hydraulic solenoid valve 16a Hydraulic cylinder for right hopper 19a 16b Hydraulic cylinder for left hopper 19b 17a Right front wheel 17b Left Front wheel 18 Main step 18a Right step 18b Left step 19 Handle 19a Right hopper 19b Left hopper 20a Right leveling arm 20b Left leveling arm 21a Hydraulic cylinder for right leveling arm 20a 21b Hydraulic cylinder for left leveling arm 20b

Claims (13)

A road paving machine comprising an expandable screed, a bar feeder for conveying the mixture, and a screw for dispersing the mixture,
expansion/contraction amount detection means for detecting the amount of expansion/contraction of the screed;
a controller that controls the amount of mixed material conveyed by the bar feeder and the screw according to the amount of expansion and contraction detected by the amount of expansion and contraction detection means,
The controller includes:
When the screed expands, calculate the amount of mix material that is missing due to the expansion, increase the speed of the bar feeder and the screw to add mix material until the missing mix material is replenished, and add mix material according to the expansion width. calculating the conveyance amount, and operating the bar feeder and the screw based on the calculated conveyance amount ;
When the screed shrinks, calculate the amount of surplus material due to the reduction, and adjust the amount of material by stopping or decelerating the bar feeder and the screw until the surplus material is used. A road paving machine, characterized in that the conveyance amount is calculated according to the reduced width, and the bar feeder and the screw are operated based on the calculated conveyance amount . The road paving machine according to claim 1 , characterized in that the controller calculates the amount of mix material missing based on the expansion width and the holding dimension in front of the screed. The road paving machine according to claim 1 , wherein the controller calculates the conveyance amount according to the expansion width based on the construction width, pavement thickness, and construction speed. The road paving machine according to claim 1 , wherein the controller calculates the amount of surplus material based on the reduced width and the holding dimension in front of the screed. The road paving machine according to claim 1 , wherein the controller calculates the conveyance amount according to the reduction width based on the construction width, pavement thickness, and construction speed. The controller stores information regarding the initial construction state, and when the screed expands or contracts, the controller controls the bar feeder and the bar feeder based on what percentage the speed should be increased or decelerated from the initial construction state. Road paver according to claim 1 , characterized in that it controls a screed. The road paving machine includes a rotation speed detection means and a rotation speed control circuit of the bar feeder and/or the screed,
The road paving machine according to claim 1 , wherein the controller controls the rotation speed of a bar feeder and/or a screed. If said screed expands,
The road paving machine according to claim 1 , wherein the controller increases the speed of the bar feeder and the screw within the allowable range of the engine to replenish the insufficient mixture material. The screed is a two-row type in which the screed is expandable and retractable to the left and right, the bar feeders are present on the left and right and the conveyance amount can be controlled separately on the left and right, and the screw is present on the left and right and the left and right are separated. If it is possible to control the conveyance amount,
The controller controls the right and/or left conveyance amount of the bar feeder and the right and/or left conveyance amount of the screw according to the right and/or left expansion and contraction amount of the screed. Road paver according to claim 1 , characterized in that: In the case where the screed is expandable and retractable to the left and right, the bar feeder is a single thread type that cannot be controlled separately for the left and right, and the screw is present on the left and right so that the conveyance amount can be controlled separately for the left and right. ,
The controller controls the amount of conveyance of the bar feeder and the amount of right and/or left conveyance of the screw according to the amount of right and/or left expansion and contraction of the screed. 1. The road paving machine according to 1 . An operator can input a correction value for the conveyance amount of the bar feeder and/or the screw, and the controller adjusts the conveyance amount of the bar feeder and/or the screw based on the correction value input by the operator. Road paver according to claim 1 , characterized in that the amount is adjusted. The road paving machine according to claim 1 , wherein the expansion/contraction amount detection means detects the expansion/contraction amount of the screed based on the operation time of the expansion/contraction cylinder. The road paving machine according to claim 1 , wherein the expansion/contraction amount detection means detects the expansion/contraction amount of the screed based on a telescoping cylinder or a sensor attached to the screed.