JP2903719B2 - How to operate the leveling machine - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for operating a leveling machine such as an asphalt finisher and a base paver.

[0002]

2. Description of the Related Art When pavement is performed on a road, in order to secure a predetermined pavement strength, it is naturally necessary to pave a pavement with a pavement thickness greater than a design value.

[0003] For this reason, conventionally, paving is carried out using structures such as curbs arranged at the side edges of the road as one guide, or the pavement thickness is measured using a gauge rod or a pavement thickness measuring device. Then, the subsequent pavement is corrected based on the measurement result and paved.

[0004]

In the former case where a reference is required outside the leveling machine, if there is no structure that can be used as the reference, it must be provided on the roadbed, which is very complicated and the work efficiency is extremely low. descend. In addition, there is a problem in that the pavement at a portion apart from the reference has to rely on the intuition of the operator, and the pavement accuracy is reduced.

The latter method using a measuring device or the like can only know the current pavement thickness, it is difficult to grasp the tendency and flow of the pavement, and the measured pavement thickness does not match the target pavement thickness. The pavement thickness is not immediately corrected even if the inclination of the screed is changed after noticing, and the result of the correction will appear at the time of traveling a predetermined distance, so the correction will be turned behind and the pavement accuracy will be reduced. There is a problem that it is not possible to perform better pavement by raising.

Accordingly, the applicant of the present invention has developed an apparatus capable of measuring an expected pavement thickness of an asphalt mixture to be spread by a screed.

[0007] It is an object of the present invention to provide a method of operating a leveling machine capable of performing better pavement by effectively using the estimated pavement thickness determined by the new apparatus.

[0008]

In order to achieve the above object, the present invention provides a screed on which asphalt mixture is spread over a traveling vehicle, and two or more measuring points arranged at a predetermined interval in a pavement direction. Leveling device provided with a measuring device for measuring the height of the asphalt mixture from the measured value measured by the measuring device, and an estimated pavement thickness of the asphalt mixture to be spread on the screed from the measurement value measured by the measuring device. On machines, the paved surface at the target point in front of the screed
Estimated pavement thickness calculated from the latest several points in
Height difference between the target point and the screed
Display the target pavement thickness calculated from
The difference between the pavement thickness and the target pavement thickness Metropolitan is configured to operate such that no.

[0009]

The measuring device measures the height of two or more measuring points arranged at predetermined intervals in the pavement direction with a height sensor, and the calculating device calculates the height of the screed from the measured value measured by the measuring device. The estimated pavement thickness of asphalt mixture to be obtained , that is, the pavement calculated from the latest several points on the paved surface
The thickness of the pavement at the target point in front of the screed on the thickness reference straight line is determined according to the progress of the pavement. The estimated pavement thickness calculated by the arithmetic unit is displayed on a display screen of a display device provided in the driver's seat.

Therefore, the operator can know the expected pavement thickness with respect to the target pavement thickness from the display on the display device, and can easily and accurately grasp the pavement tendency and the like to perform the pavement accurately.

[0011]

BRIEF DESCRIPTION OF THE DRAWINGS The accompanying drawings show an example of an asphalt finisher embodying the present invention, and reference numeral 1 in the figure denotes a traveling vehicle of an asphalt finisher AF. A hopper 2 for storing asphalt mixture is provided at a front portion of the traveling vehicle 1. The asphalt mixture in the hopper 2 is transported rearward (to the right in FIG. 1) by a feeder at the lower part of the vehicle body, and thereafter spread evenly to the left and right by a screw and spread by a pair of left and right screeds 5.

The screed 5 is supported via a leveling arm 6 by a support shaft 7 provided on a substantially central side surface of the traveling vehicle 1. The support shaft 7 is moved up and down by a pivot cylinder 8. The basic structure of the asphalt finisher AF is well known.

Reference numeral 11 denotes a measuring device provided on each of the right and left sides. The measuring device 11 measures a first height sensor 13 provided at the tip of the measuring arm 12, a second height sensor 14 provided at the center of the measuring arm, and an inclination angle of the measuring arm 12. And an inclination sensor 15. The base end (right end in the figure) of the measurement arm 12 is supported by a pin on a frame 5 a that supports the screed 5, whereby the measurement arm 12 tilts evenly with the screed 5.

Although various types of first and second height sensors 13 and 14 can be considered, here, sensors using ultrasonic waves are used. Also, as shown in FIG. 3, the distance between the two sensors 13 and 14 is set to で あ れ ば of the distance M between the second distance sensor 14 and the rear end of the screed 5 (it is sufficient if the distance M is a fractional integer). , Screed 5 of both sensors 13 and 14
Relative height H ₀ is screed 5 and the measuring arm 12 and the like are set so as to always be a constant value even if any inclination with respect.

Reference numeral 17 denotes a distance sensor provided at the lower front end of the traveling vehicle 1 for calculating the traveling distance.

Height sensors 13 and 14 and tilt sensor 1
The arithmetic unit 30 is connected to the distance sensor 5 and the distance sensor 17 (see FIG. 2). The arithmetic unit 30 includes the height sensor 1
Receiving the analog outputs of 3, 14 and the tilt sensor 15,
An A / D (analog-digital) converter 31 for converting this into a digital output, and an I / O (input-input) to which each digital output of the A / D converter 31 and the distance sensor 17 is input.
Output) interface 32, and an operation unit 3 for performing an operation based on data from the I / O interface 32
3, a data storage unit 34 for inputting and storing the numerical value obtained by the arithmetic unit 33 and outputting the numerical value to the arithmetic unit, and an I / O interface 35 for processing the numerical value calculated by the arithmetic unit 33. It is configured. The signal output from the I / O interface 35 is sent to the electromagnetic valve 36 for adjusting the expansion and contraction of the pivot cylinder 8 and the display device 20.

The display device 20 is provided in a driver's seat 21 provided in the traveling vehicle 1. FIG. 7 shows an example of the display screen of the display device 20. Display device 20, the result calculated by the arithmetic unit 30 as described later, i.e., pavement thickness of the current, the expected pavement thickness, the difference between the expected pavement thickness between the target pavement thickness t _o epsilon etc., given previously It was to the left and right separately displayed along with the target pavement thickness t _o the like. The display items are not limited to the above, and may be increased or decreased as necessary.

The arithmetic unit 30 is provided for each time the traveling vehicle 1 travels the distance between the two height sensors 13 and 14 (M / 2, where M represents the distance between the second height sensor 14 and the screed 5). The required calculation is performed based on the measurement signals from the height sensors 13 and 14 measured at the same time.

The main operation contents of the operation device 30 are as follows. (1) Two measurement points P ₁ , P ₂ , P ₂ , P ₃ , P ₃ , P ₄ , simultaneously measured by a pair of height sensors 13, 14.
_{P 4, P 5, P 5} , P 6 ... height difference [delta] ₁ of, [delta] ₂ ... calculates the pavement thickness t ₁ of the (see FIG. 6) each measuring point P ₁ at the same time, P ₂ ......, t ₂ ... To calculate

(2) The measurement points Q ₁ , Q ₂ , Q ₃ , Q _4, ... Of the already-paved surface obtained when measuring the pavement thicknesses t ₁ . Reference straight line l
(Y = ax + b) and to calculate the expected pavement thickness at a predetermined position in front of the screed.

(3) In the case of automatic control (operation), a target pavement thickness position at a target point a predetermined distance M ahead of the screed 5 is determined, and a difference between this position and a position on the pavement thickness reference straight line 1 is calculated. Calculating the vertical operation amount L of the pivot cylinder 8 to change the position of the screed 5 so as to eliminate it. In addition, as understood from the above,
The “so-called pavement thickness” is a pavement calculated from the latest several points
The pavement thickness at the target point in front of the screed on the
The "target pavement thickness" is the target in front of the screed.
Calculated from the height difference (δ) between the point and the point in between
It refers to the pavement thickness at the target point.

At this time, since the thickness of the pavement affects not only the inclination of the screed 5, but also the properties and supply amount of the asphalt mixture, the traveling speed of the vehicle, and the like, these factors are also taken into consideration. In the case of manual operation, the operator at the driver's seat 21 knows the estimated pavement thickness from the display on the display device 20 and operates based on this. In the case of automatic operation, a command signal of the operation amount L of the pivot cylinder 8 calculated above is sent to an electromagnetic valve 36 interposed in a hydraulic circuit (not shown), and the electromagnetic valve 36 is operated. The pivot cylinder 8 is operated to extend and retract.

Here, two measurement points P ₁ , P ₂ , P ₂ , and P ₂ simultaneously measured by the pair of height sensors 13 and 14 are shown.
The height differences δ ₁ , δ of P ₃ , P ₃ , P ₄ , P ₄ , P ₅ , P ₅ , P ₆ ...
How to calculate the ₂ ..., and each measurement point P _1, P ₂ ... method of calculating pavement thickness t _1, t ₂ ... a will be described with reference to Figure 4. The height difference δ is calculated by the following equation 1.

[0024]

Δ = H ₂ − (H ₁ −Mtan θ ₁ )

Here, H ₁ : a value detected by the first height sensor H ₂ : a value detected by the second height sensor M: a distance between the first and second height sensors θ ₁ : Tilt of measurement arm 12

The pavement thickness t is calculated by the following equation (2).

[0027]

## EQU2 ## t = H ₂₁ + δ-Mtan θ ₂ -H ₀

Here, H ₂₁ : a value detected by the second height sensor δ: a value calculated by the above equation (1) M: same as above θ ₂ : inclination of the measuring arm H ₀ : height sensor Difference between screed and

The above equations (1) and (2) are shown for easy understanding of the method of calculating the height difference δ and the pavement thickness t. The asphalt finisher AF shown in FIG. 1 and FIG.
Are slightly different from those of the measuring device 11 indicated by. In order to actually measure with the measuring device 11 of the present embodiment, since the height sensors 13 and 14 are arranged at a distance M / 2, the height difference δ and the pavement thickness t at each distance M / 2 are calculated. It is calculated (see FIG. 5).

In the above formulas (1) and (2), the height difference δ and the pavement thickness t do not take the inclination θ into account, so there is a slight difference from the actual values. I can ignore it.

Next, a method of operating the leveling machine configured as described above will be described. The pavement of the road by the asphalt finisher AF is carried out in the same manner as in the prior art, while the traveling vehicle 1 is traveling at a constant speed, the asphalt mixture in the hopper 2 is fed to the screw by a feeder and spread uniformly in front of the screed 5. Spread the mixture with screed 5.

In the above description, the traveling distance of the vehicle 1 is measured by the distance sensor 17, and every time the traveling distance becomes M / 2, the height from the roadbed surface is measured by the first and second height sensors 13 and 14. The measurement result is calculated by the arithmetic unit 30
Output to

The arithmetic unit 30 calculates the output signals of the height sensors 13 and 14, the distance sensor 17, and the inclination sensor 15
As described above, the height difference δ and the pavement thickness t are calculated. Then, based on these values, the pavement thickness reference straight line l: y = ax + b
Is calculated. When calculating the pavement thickness reference straight line 1, for example, the latest several points on the already-paved surface (Q ₁ , Q ₂ ,
Q ₃ and Q ₄ ).

Next, the arithmetic unit 30 calculates the expected pavement thickness at a target point at a distance M away from the screed 5 by:
The height difference is calculated from the height differences δ ₄ , δ _{5 and the} like. This estimated pavement thickness is displayed on the display device 20.

As described above, in the case of the manual operation, the operator knows the estimated pavement thickness by looking at the display device 20 of the driver's seat 21 and obtains the position on the pavement thickness reference straight line 1 at the target point and the target pavement thickness t ₀ . The operation is performed so that the difference ε from the position is eliminated.
In the case of automatic control, the operation unit 30 determines the amount of vertical operation of the pivot cylinder 8 at which the difference ε between the position on the pavement thickness reference straight line 1 at the target point and the position of the target pavement thickness t ₀ disappears. The result is sent to the electromagnetic valve 36 via the I / O interface 35, and the inclination of the screed 5 is changed.

The above is repeated every time the vehicle 1 travels a distance M / 2, so that the screed 5 is controlled such that the pavement thickness ahead of the distance M always becomes an ideal value.

The embodiments other than the above, technical matters, and the like will be listed below. (1) In the above embodiment, the separation distance between the height sensors 13 and 14 is set to M / 2, but is not limited to this and may be set to M or M / 3. However, the use of M / 2 or M / 3 as in the embodiment has the advantage that the size of the measuring device 11 can be reduced.

(2) The height sensors 13 and 14 are not limited to ultrasonic sensors, but may be laser-type or telescopic cylinders, and the specific structure is arbitrary.

(3) In the above embodiment, the latest four points after pavement are used to calculate the pavement thickness reference straight line l.
Although the value is obtained by the multiplication method, the present invention is not limited to this, and may be calculated based on the latest three or five points.

[0040]

As described above, the operating method of the leveling machine according to the present invention is characterized in that a traveling vehicle is provided with a screed for spreading asphalt mixture and two or more screeds arranged at a predetermined interval in the pavement direction. A bed provided with a measuring device for measuring the height of a measuring point by a height sensor, and an arithmetic unit for calculating an estimated pavement thickness of the asphalt mixture to be spread and spread on the screed from the measured value measured by the measuring device. On a leveling machine at a target point in front of the screed
The estimated pavement thickness calculated from the latest several points of the
The height difference between points and the height between the target point and the screed
The target pavement thickness calculated from the low difference is displayed on the display device,
Since the difference between the expected pavement thickness and the target pavement thickness Metropolitan is configured to operate such that without knowing the tendency of paved from the displayed predicted pavement thickness and the target pavement thickness relationship display device, the target pavement thickness Prefecture When there is a difference from the estimated pavement thickness, the correction can be performed without missing the machine and a highly accurate pavement can be performed.

[Brief description of the drawings]

FIG. 1 is a side view showing an example of an asphalt finisher embodying the present invention.

FIG. 2 is a block diagram of an arithmetic unit.

FIG. 3 is an explanatory diagram showing a relationship between a measuring device and a screed.

FIG. 4 is an explanatory diagram for obtaining a height difference and a pavement thickness of a roadbed.

FIG. 5 is an explanatory diagram for obtaining a height difference and a pavement thickness of a roadbed according to the embodiment.

FIG. 6 is an explanatory diagram of calculation of an estimated pavement thickness.

FIG. 7 is a front view showing an example of a display screen of the display device.

[Explanation of symbols]

1 traveling vehicle 5 screed 11 measuring device 13 first height sensor 14 and the second height sensor is 20 display 21 the driver's seat 30 arithmetic unit t ₀ target pavement thickness

Continued on the front page (72) Inventor Tetsuo Ogawa 730, Gunma-cho, Gunma-cho, Gunma-gun Inside the Takasaki Plant of Niigata Iron Works Co., Ltd. (72) Inventor Akio Ishii 730, Gunma-cho, Gunma-cho, Gunma-gun, Gunma Prefecture Takasaki, Niigata Co., Ltd. In-plant (56) References JP-A-63-121606 (JP, U) (58) Field surveyed (Int. Cl. ⁶ , DB name) E01C 19/48

Claims (1)

(57) [Claims] 1. A screed for spreading asphalt mixture on a traveling vehicle, a measuring device for measuring heights of two or more measuring points arranged at a predetermined interval in a pavement direction by a height sensor, and the measuring device The latest number of paved surfaces at the target point in front of the screed in a leveling machine equipped with an arithmetic unit for calculating the expected pavement thickness of the asphalt mixture to be spread on the screed from the measurement value measured by
The estimated pavement thickness calculated from the point and the height difference of the target point
And the difference between the height of the point between the target point and the screed
The displayed target pavement thickness is displayed on a display device, and the estimated pavement thickness and
Laying leveling machine operating method is characterized in that the difference between the target pavement thickness Metropolitan operated so no.