JP7640962B2 - Warning groove, road cutting machine and road cutting method - Google Patents

Description

Application of Article 30, Paragraph 2 of the Patent Act The paper "Study on Directional Rumble Strips for Attention by Vehicle Motion Simulation" to be presented at the 75th Annual Academic Lecture Meeting of the JSCE National Convention in 2020 was submitted to the JSCE on March 31, 2020. The paper "Analysis of Vehicle Vibration and Human Experience of Directional Rumble Strips" to be presented at the 40th Traffic Engineering Research Symposium was submitted to the Traffic Engineering Research Society on May 8, 2020. The paper "Analysis of Vehicle Vibration and Human Experience of Directional Rumble Strips" was published at the 40th Traffic Engineering Research Symposium, held online from September 7 to September 8, 2020. The paper "Study on Directional Rumble Strips for Attention by Vehicle Motion Simulation" was published at the 75th Annual Academic Lecture Meeting of the JSCE National Convention in 2020, held online from September 9 to September 11, 2020.

The present invention relates to a warning groove that is formed in a plurality of grooves on the road surface at a specified interval and that warns the driver of a vehicle when the vehicle is traveling in the opposite direction (backward driving) to the direction in which the vehicle should travel on the road, and to a manufacturing technology for the warning groove.

The act of driving a vehicle in the opposite direction to the direction in which it should go (direction of travel) on a road (so-called "wrong-way driving") poses a very high risk of leading to serious accidents involving not only the wrong-way vehicle but also other vehicles and drivers who are obeying traffic rules, and has become a major social problem in recent years.
As countermeasures against wrong-way driving, measures to "make it difficult to enter by mistake" or "to immediately notify the driver if he/she enters by mistake" have been attempted, such as measures to improve signs and road markings, measures to install obstacles, or measures to utilize communication technology (IT). As part of such measures, technology has been attempted to call the attention of drivers of cars going the wrong way (wrong-way vehicles) by improving the road surface shape.

Conventional technology for preventing wrong-way driving by alerting drivers of vehicles going the wrong way involves, for example, forming a convex portion of a certain shape in the direction of travel on the pavement surface of a road, and when a vehicle goes over the convex portion, the driver of the wrong-way driving vehicle detects a clear abnormal driving noise and vibration, thereby constructing a road surface that alerts the driver of the wrong-way driving vehicle (warning road surface) (see Patent Document 1).
The related art (Patent Document 1) involves constructing a convex attention-attracting structure on the road surface, which has the effect of attracting the driver's attention by causing a large impact when a vehicle runs over the structure.
However, the impact on the vehicle, passengers, and loaded items is large, and when machinery used in snow removal or other work passes over the convex warning structures, it may get caught on the structures, causing serious damage to the machinery and workers, as well as causing damage to the machinery. In addition, the convex warning structures may be scraped off by the snow removal machine.

Other conventional technologies include a road surface cutting machine and cutting method in which distance sensors are provided on the running wheels of a small road surface cutting machine, and a sensor that detects the amount of up and down movement is provided on the height indicator of the cutting equipment, and based on the data from each sensor, the timing for up and down movement of the cutting device relative to a pre-input movement pitch and the appropriate amount of lowering of the cutting teeth tip to ensure a pre-input cutting depth are output as hydraulic control signals for a hydraulic actuator to control the cutting device (see Patent Document 2).
However, in this conventional technology (Patent Document 2), it is not intended to precisely control the amount of cylinder movement (the amount of lift of the cutting mechanism) in millimeters in accordance with the travel distance, and there is no disclosure of cutting and constructing a smooth slope surface.

Patent No. 5873727 Patent No. 6552279

The present invention was proposed in consideration of the problems with the conventional technology described above, and aims to provide a warning groove, road surface cutting machine, and road surface cutting method that can cut and construct a smooth slope surface to alert drivers of vehicles going the wrong way and minimize the impact of impact on the vehicle and passengers.

The attention warning groove (M1) of the present invention has an arc-shaped portion (M1A) and a slope-shaped portion (M1B), the arc-shaped portion (M1A) is located at the front end in the direction in which the vehicle should travel (X: traveling direction: forward direction) and is formed to a predetermined cutting depth (D1), and the slope-shaped portion (M1B) is composed of an inclined surface that rises continuously from the arc-shaped portion (M1A) so as to reach the (uncut) road surface (SF), and the inclined surface is characterized in that it is composed of a large number of continuous fine step-like portions that rise in the vertical direction by a fine distance (δV: for example, 1 mm) every fine distance (δL: for example, 10 mm) in the direction in which the vehicle should travel (X).
Here, it is preferable that the vertical distance from the road surface (SF) to the deepest part of the arc-shaped portion (M1A) is 50 mm or less. If the vertical distance from the road surface (SF) to the deepest part of the arc-shaped portion (M1A) is greater than 50 mm, the impact given to a car passing through the warning groove (M1) is too large, and may have a negative effect, just like a collapse in the road surface, even if the car is traveling in the direction in which it should travel (X: traveling direction: forward direction).

The attention-attracting groove (M2) of the present invention is composed of a first and a second inclined surface (M2A, M2B),
The first inclined surface (M2A) is located at the front end in the direction in which the vehicle should move (X: traveling direction: forward direction) and has an inclination that descends to the deepest part of the predetermined cutting depth (D2);
The second slope (M2B) is constituted by a slope that rises from the deepest part to reach the (uncut) road surface (SF);
The inclination angle (ξ) of the first inclined surface (M2A) relative to the road surface (SF) is larger than the inclination angle (θ) of the second inclined surface (M2B) relative to the road surface (SF), and the inclination angle (ξ) of the first inclined surface (M2A) is the complement angle (ξ + θ = 90°) of the inclination angle (θ) of the second inclined surface (M2B).

The road surface cutting machine (100) of the present invention includes a traveling device (guide wheels 2 and drive wheels 1) for moving on a road surface (SF), a cutting device (3) for cutting the road surface (SF), a distance sensor (4) for measuring a distance traveled (by the traveling device), and a control device (10) into which the measurement results of the distance sensor (4) are input,
The hydraulic cylinder (8) moves the cutting device (3) in a vertical direction (by vertically moving the guide wheels 2 and the vehicle body 6 constituting the traveling device), a pressure oil piping system (11) that supplies or discharges pressure oil to the hydraulic cylinder (8), an electromagnetic valve (12: a high-speed response valve) installed in the pressure oil piping system (11), and a sensor (13: for example, a linear potentiometer sensor) that measures the amount of displacement of a rod (8A) connected to a piston of the hydraulic cylinder (8),
The control device (10) has a function of determining the vertical position of the cutting device (3) based on the measurement result of the sensor (13) that measures the displacement amount of the rod (8A);
The device is characterized by having a function of controlling the amount of pressurized oil supplied to the hydraulic cylinder (8) by controlling the solenoid valve (12) of the pressurized oil piping system (11) based on the measurement results of the distance sensor (4), thereby adjusting the vertical position of the cutting device (3).

The road surface milling method of the present invention is a road surface milling method for milling a warning groove (M1) having an arc-shaped portion (M1A) and a slope-shaped portion (M1B), the arc-shaped portion (M1A) being located at the front end in the direction in which the vehicle should travel (X: traveling direction: forward direction) and formed to a predetermined milling depth (D1: 50 mm or less), and the slope-shaped portion (M1B) being configured by an inclined surface that rises continuously from the arc-shaped portion (M1A) so as to reach the (unmilled) road surface (SF),
A road surface cutting machine (100) is driven in the direction in which the road extends to cut a warning groove (M1);
a step of lowering a cutting device (3) of a road surface cutting machine (100) from a road surface (SF) to a predetermined cutting depth (D1: 50 mm or less) to cut a circular arc-shaped portion (M1A) at a front end of a warning groove (M1);
The method includes a step of cutting a slope-shaped portion (M1B) that is continuous with the arc-shaped portion (M1A) and has an inclined surface that rises to reach a (non-cut) road surface (SF),
The process of cutting the slope-like portion (M1B) is characterized in that the cycle of raising the cutting device (3) vertically by a minute distance (δV: for example, 1 mm) for every minute distance (δL: for example, 10 mm) in the direction in which the road (SF) extends (forward driving direction X or reverse driving direction Y) and cutting the minute stepped portion is repeated many times in succession over a predetermined length in the direction in which the vehicle should travel (length of the warning groove M1 in the direction in which the vehicle should travel: for example, 1 m) in the direction in which the vehicle should travel (X).
In the road surface cutting method of the present invention, when the width dimension of the cutting device (3) is smaller than the width dimension of the road, it is preferable to align the starting points of the attention warning grooves (M1) and cut the attention warning grooves (M1) multiple times by moving in the road width direction multiple times, taking into consideration the required overlap amount (the amount of overlap in the road width direction when the attention warning groove M1 is cut again adjacent to the road width direction).

Alternatively, the road surface cutting method of the present invention is a road surface cutting method for cutting a caution groove (M2) which is composed of first and second inclined surfaces (M2A, M2B), the first inclined surface (M2A) is located at the front end of the direction in which the vehicle should travel (X: traveling direction: forward direction) and has a slope that descends to the deepest part of a predetermined cutting depth (D2), and the second inclined surface (M2B) is composed of an inclined surface that rises from the deepest part to reach a (non-cut) road surface (SF), the inclination angle (ξ) of the first inclined surface (M2A) with respect to the road surface (SF) is larger than the inclination angle (θ) of the second inclined surface (M2B) with respect to the road surface (SF), and the inclination angle (ξ) of the first inclined surface (M2A) is a complement angle (ξ + θ = 90°) of the inclination angle (θ) of the second inclined surface (M2B),
A road surface cutting machine (100) is run in the width direction of the road to cut a warning groove (M2);
The cutting device (3) of the road surface cutting machine (100) has an approximately cylindrical shape, and cuts the warning groove (M2) by lowering the cylindrical cutting device (3) with its rotation axis inclined relative to the road surface (SF), and the inclination angle of the rotation axis of the cutting device (3) relative to the road surface (SF) is equal to the inclination angle (θ) of the second inclined surface (M2B) relative to the road surface (SF).
Here, when the length of the cutting device (3) of the road surface cutting machine (100) is longer than the length from the end of the warning groove (M2) to the edge of the road, it is preferable to repeat the process of lowering the cylindrical cutting device (3) with its rotation axis inclined relative to the road surface (SF) multiple times for the same warning groove (M2).

According to the attention-attracting groove (M1) of the present invention, which includes the arc-shaped portion (M1A) and the slope-shaped portion (M1B), the slope-shaped portion (M1A) is continuous with the arc-shaped portion (M1A) at the front end in the direction in which the vehicle should travel (X: travel direction: forward direction) and reaches the (uncut) road surface (SF), so that the wheels of a vehicle traveling in the travel direction do not get stuck in the arc-shaped portion (M1A) due to the inertia of traveling, but jump over the arc-shaped portion (M1A) and land on the area of the slope-shaped portion (M1B) ahead of the direction in which the vehicle should travel (travel direction). The depth dimension of the slope-shaped portion (M1B) with respect to the road surface (SF) in the area ahead of the direction in which the vehicle should travel is much shorter (shallower) than the arc-shaped portion (M1A), so the impact on the wheels when they land on the slope-shaped portion (M1B) is relatively small, and the impact felt by the driver is also relatively small. Furthermore, the impact that a vehicle passing through the warning groove (M1) and the devices attached to the vehicle receive is small, and the possibility of damage is low.
On the other hand, in the case of a vehicle (wrong-way vehicle: wrong-way vehicle) traveling in the opposite direction (wrong-way direction Y) to the direction in which the vehicle should travel (X: travel direction: forward direction), the wheels travel along the slope-shaped portion (M1B) of the warning groove (M1) and collide with the arc-shaped portion (M1A) of the warning groove (M1) immediately after reaching the bottom. The impact felt by the driver of the wrong-way vehicle at the time of the collision is much greater than that felt when traveling in the normal direction.
In addition, the vertical component of the impact force of the collision causes the car to jump upward and rise above the road surface (SF). Therefore, the step when the wrong-way car goes over the warning groove (M1) is the distance (D1 + J1) obtained by adding the depth (D1) of the warning groove to the distance (J1) it jumps up to above the road surface (SF). In addition to the impact, the impact of going over the distance (D1 + J1) obtained by adding the depth (D1) of the warning groove to the distance (J1) it jumps up to above the road surface (SF) is added to the wrong-way car, so the driver of the wrong-way car feels a very large impact, and by combining this sensation with signs installed on the side of the road and no-entry marks painted on the warning groove, the driver can reliably recognize that the car is "going the wrong way" with respect to the direction of travel.

In addition, according to the attention warning groove (M2) of the present invention, which is composed of the first and second inclined surfaces (M2A, M2B), the wheels of a vehicle traveling in the direction in which it should travel (direction of travel) jump over the first inclined surface (M2A) and the deepest part of the groove, and land on the area of the second inclined surface (M2B) ahead of the direction in which it should travel. The depth dimension of the area ahead of the direction in which it should travel on the second inclined surface (M2B) is much shorter (shallower) than the depth dimension (D2) of the deepest part, so the impact felt by the driver is relatively small, and the impact received by the vehicle passing through the attention warning groove (M2) and the equipment installed on the vehicle is also small. Therefore, the possibility of damage is low.
On the other hand, in the case of a vehicle (wrong-way vehicle) traveling in the opposite direction to the direction in which the vehicle should travel, the wheels travel on the second inclined surface (M2B) and when they reach the deepest part, the inclination angle (ξ) of the first inclined surface (M2A) with respect to the road surface (SF) is relatively large, so the wheels traveling on the second inclined surface (M2B) collide with the first inclined surface (M2A). The impact felt by the driver at the time of the collision is much greater than when the vehicle is traveling in the direction in which the vehicle should travel. In addition, the vertical component of the impact force of the collision causes the vehicle to jump upward, so the step when the vehicle goes over the warning groove (M2) is the depth (D2) of the deepest part plus the distance it jumps up above the road surface (SF). The impact of going over the step, which is the depth (D2) of the deepest part plus the distance it jumps up above the road surface, is added to the vehicle traveling in the wrong direction, so the driver of the vehicle traveling in the wrong direction experiences a very large impact.

Here, in order to reduce the shock received by the vehicle and the driver when traveling in the normal direction, it is desirable that the slope portion (M1B) is smooth.
According to the road cutting machine (100) or road cutting method of the present invention, there is provided a hydraulic cylinder (8) that moves the cutting device (3) in a vertical direction, and a pressure oil piping system (11) that supplies or discharges pressure oil to the hydraulic cylinder (8), and the pressure oil piping system (11) is provided with an electromagnetic valve (12: high-speed response valve) and has a sensor (13: for example, a linear potentiometer) that measures the displacement of a rod (8A) connected to the piston of the hydraulic cylinder (8), and a control device (10) that controls the movement of the rod (8A) by measuring the displacement of the rod (8A). The hydraulic system has a function of determining the vertical position of the cutting device (3) based on the measurement results of the sensor (13) connected to the hydraulic cylinder (8) and a function of controlling the solenoid valve (12) of the pressurized oil piping system (11) based on the measurement results of the distance sensor (4) to control the amount of pressurized oil supplied to the hydraulic cylinder (8), thereby adjusting the vertical position of the cutting device (3). Therefore, the amount of extension or contraction of the hydraulic cylinder (8), i.e., the vertical position of the cutting device (3), can be controlled with high precision (for example, in millimeters), and the position of the cutting edge of the cutting tool of the cutting device (3) can also be controlled with high precision.
For example, when cutting the sloped portion (M1B) or inclined surface (of the attention-attention groove M1), the cutting device (3) can be raised vertically by a minute distance (δV: for example, 1 mm) for each minute distance (δL: for example, 10 mm) in the direction in which the road extends, to cut a minute stepped portion. By repeatedly performing this cycle of cutting the minute stepped portion many times in succession over a predetermined length in the direction in which the vehicle should travel (length of the attention-attention groove M in the direction in which the vehicle should travel: for example, 1 m), a smooth sloped portion (M1B) or inclined surface can be cut.
As a result of controlling the minute displacement from the overall size of each groove, the sloped portion (M1B) or the inclined surface may be treated as a substantially smooth surface.

As a result, the cutting edge position of the cutting tool of the cutting device (3) corresponding to the traveling distance of the road surface cutting machine (100) can be accurately identified, and the road surface can be accurately cut with the cutting device (3), so that the sloped portion (M1B) or inclined surface becomes smooth and the unevenness in the sloped portion (M1B) is reduced.
Furthermore, with such a smooth slope portion (M1B), when traveling in the normal direction, the impact when the wheels jump over the arc-shaped portion (M1A) and land on the slope portion (M1B) is extremely small, and the impact received by the vehicle and the driver, etc. is also small, and there is little risk of damage to equipment installed in the vehicle.

Here, when cutting the warning groove (M1) having an arc-shaped portion (M1A) and a slope-shaped portion (M1B), the running direction of the road cutting machine (100) is the extension direction of the road, but cutting of the warning groove (M2) having first and second inclined surfaces (M2A, M2B) is carried out while the road cutting machine (100) is running in the width direction of the road.
Therefore, even if the road surface cutting machine (100) cannot be run in the direction in which the road extends, if the road surface cutting machine (100) can be run in the width direction of the road, it is possible to cut a warning groove (M2) having first and second inclined surfaces (M2A, M2B) into the road surface.

FIG. 2 is an explanatory cross-sectional view of a first embodiment of the attention-attracting groove of the present invention. FIG. 2 is a plan view of the attention-attention groove of FIG. 1 . FIG. 2 is an enlarged cross-sectional view of a portion indicated by the symbol A in FIG. 1 . 10A and 10B are explanatory diagrams showing the operation and effect of the first embodiment of the attention-attracting groove; FIG. 4 is an explanatory cross-sectional view of a second embodiment of the attention-attracting groove of the present invention. FIG. 6 is a plan view of the attention-attention groove of FIG. 5 . FIG. 1 is an explanatory diagram showing an embodiment of a road surface cutting machine. FIG. 2 is an enlarged explanatory view of a mechanism for vertically moving guide wheels of a road cutting machine. FIG. 9 is a plan view of the mechanism shown in FIG. 8 . FIG. 9 is a diagram showing a hydraulic circuit for supplying pressure oil to the hydraulic cylinder of FIG. 8 . 5 is a flowchart showing a process for cutting the attention-warning grooves shown in FIGS. 1 to 4 into a road surface. 7 is an explanatory diagram showing one step of cutting the warning groove shown in Figures 5 and 6 into the road surface. 13 is an explanatory diagram of one step of cutting the attention-warning groove shown in FIGS. 5 and 6 into the road surface, and is an explanatory diagram showing a step subsequent to FIG. 12 . FIG. FIG. 7 is a process diagram for cutting the warning grooves shown in FIGS. 5 and 6 into a road surface. 15 is a process diagram showing a process of cutting the attention-warning grooves shown in FIGS. 5 and 6 into a road surface, the process being a step following FIG. 14 . FIG.

Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.
First, a first embodiment of the attention-attracting groove of the present invention will be described with reference to FIGS.
1 and 2, the direction in which the vehicle should move (arrow X: forward direction, normal moving direction) is from left to right. The direction opposite to the direction X in which the vehicle should move is indicated by arrow Y, and the opposite direction Y in Fig. 1 and Fig. 2 is from right to left. In Fig. 2, the vehicle width on the road surface is indicated by symbol B1.
As shown in FIG. 1, the attention drawing groove M1 according to the first embodiment has an arc-shaped portion M1A and a slope-shaped portion M1B.

1 and 2, the arc-shaped portion M1A is located at the front end (left side in FIG. 1 and FIG. 2) of the forward direction X in which the vehicle should move, and is formed with a predetermined cutting depth D1. The end of the arc-shaped portion M1A on the forward direction X side has the cutting depth D1, which is the deepest part of the arc-shaped portion M1A. Here, the cutting depth D1 of the arc-shaped portion M1A (the vertical distance from the road surface SF of the deepest part of the arc-shaped portion M1A) is preferably set to 50 mm or less. If the cutting depth D1 is greater than 50 mm, even if the vehicle is traveling in the direction in which the vehicle should move (X: forward direction), the impact given to the vehicle passing through the attention groove M1 will be too large, which will be similar to a collapse in the road surface, and may have a negative impact on the vehicle and its driver.
The slope portion M1B is formed contiguous to the arc portion M1A on the forward direction X side. The slope portion M1B is formed as an inclined surface that rises to reach the (uncut) road surface SF.
In FIG. 1, the length of the attention warning groove M1 (length of one span) is indicated by the symbol L1, the length of the arc-shaped portion M1A is indicated by the symbol L11, the length of the slope-shaped portion M1B is indicated by the symbol L12, and the distance between adjacent attention warning grooves M1 in the road direction is indicated by the symbol I.
Here, the cutting direction C1 of the warning groove M1 by the road surface cutting machine 100 (FIG. 7) is the same as the vehicle traveling direction X. The boundary between the arc-shaped portion M1A and the slope-shaped portion M1B is indicated by a dashed line BD1 in FIG.

The inclined surface of the slope portion M1B will be described with reference to Fig. 3. In Fig. 3, the slope portion M1B has a smooth slope portion M1B formed by a series of minute step-like portions that rise vertically by minute distances δV (e.g., 1 mm) for every minute distance δL (e.g., 10 mm) in the direction in which the vehicle should travel (arrow X: forward direction). A number of such minute step-like portions continue for a predetermined length (e.g., 1 m), thereby forming the slope portion M1B. The taper (gradient) of the slope portion M1B in the first embodiment can be expressed as δV/δL.
In the explanation with reference to Fig. 3, the minute distance δL = 10 mm in the direction in which the vehicle should move (X: forward direction) and the minute distance δV = 1 mm in the vertical direction are exemplified, but the minute distances δL and δV are selected based on the construction specifications. Here, one of the features of the embodiment of the present invention is that the minute distances δL and δV can be precisely set in millimeters.
1 and 2, the attention grooves M1 are formed in two places continuously in the running direction of the car, but in addition to the attention grooves M1, more attention grooves M1 can be formed continuously in Fig. 1 and 2. The size of the attention grooves M1 in the road width direction (direction perpendicular to the paper surface of Fig. 1: vertical direction in Fig. 2) and the number of attention grooves M to be formed are appropriately determined depending on the various specifications and construction conditions of the road on which the attention grooves M are to be formed.

The effect of the attention-attracting groove M1 according to the first embodiment shown in FIGS. 1 to 3 will be described with reference to FIG.
When the wheel W of an automobile traveling in the direction X in which the automobile should travel reaches the starting point P1 of the attention warning groove M1 (wheel W1), the wheel W jumps over the arc-shaped portion M1A without getting stuck in the arc-shaped portion M1A due to the inertia of the travel and lands (wheel W2) in an area (point P2) on the slope portion M1B ahead in the normal traveling direction X. After that, the automobile ascends the slope portion M1B of the attention warning groove M1, reaches a point P3 on the road surface SF, and then heads toward the starting point P4 of the next attention warning groove M1.
Here, the depth dimension of the slope portion M1B relative to the road surface SF in the area (point P2) ahead in the traveling direction is much shorter than the arc-shaped portion M1A (the depth dimension D1 of its deepest part D1), and the slope portion M1B is a smooth slope. Therefore, the impact when the wheel W lands on point P2 is extremely small, and the impact felt by the vehicle and the driver is also relatively small. Furthermore, the impact received by the vehicle passing through the warning groove M1 and the equipment installed on the vehicle is also small, and the possibility of damage is low.

On the other hand, in the case of a car traveling in the opposite direction Y to the normal traveling direction, the wheel W travels along the sloped portion M1B of the attention groove M1 and collides with the arc-shaped portion M1A of the attention groove M1 immediately after reaching the lowest point (point P5) of the sloped portion M1B (immediately after the state of the wheel W3). The impact felt by the driver of the car traveling in the wrong direction at the time of the collision is much greater than when traveling in the normal traveling direction X. In addition, the vertical component of the impact force when the wheel W collides with the arc-shaped portion M1A causes the wheel W (car) to jump upward and rise above the road surface SF. The raised wheel is indicated by the symbol W4, and the vertical distance by which the wheel W4 rises above the road surface SF is indicated by the symbol J1.
Therefore, the step when the reverse-driving car goes over the attention groove M1 is the distance (D1+J1) obtained by adding the distance J1 that the wheel W4 jumped up above the road surface SF to the depth D1 of the attention groove M1. In addition to the impact when the wheel W collides with the arc-shaped portion M1A, the impact of rising and landing by the distance (D1+J1) obtained by adding the distance J1 that the wheel W4 jumped up above the road surface SF to the depth D1 of the attention groove M1 (the impact of going over the distance "D1+J1") is added to the reverse-driving car, so the driver of the reverse-driving car feels a very large impact, and by combining this sensation with the signboard installed on the side of the road and the no entry mark painted on the attention groove, the driver can reliably recognize that the car is "going in the wrong direction" with respect to the traveling direction. If the reverse driving continues, the driver of the car will experience the above-mentioned very large impact continuously.

Next, a second embodiment of the attention-attracting groove of the present invention will be described with reference to FIGS.
5 and 6, the direction in which the vehicle should move (arrow X: forward direction, normal moving direction) is from left to right, and the opposite direction to the direction in which the vehicle should move (arrow Y) is from right to left. The width of the vehicle on the road surface is indicated by the symbol B2 in FIG.
The attention drawing groove M2 according to the second embodiment shown in Figs. 5 and 6 is composed of a first inclined surface M2A and a second inclined surface M2B.
The first inclined surface M2A is located at the front end (left side in Figs. 5 and 6) in the direction X in which the vehicle should travel, and has an inclination that descends to the deepest part of the predetermined cutting depth D2.
The second inclined surface M2B is formed on the forward direction X side (right side in Figures 5 and 6) contiguous to the deepest part (depth D2 position) of the first inclined surface M2A, and the second inclined surface M2B is formed as an inclined surface that rises to reach the road surface SF.
The second inclined surface M2B is formed by cutting the road surface with the rotation axis of the rotary cutting device 3 inclined with respect to the road surface SF, as described later with reference to Figures 12 to 15. However, similar to the sloped portion M1B of the attention-attracting groove M1 shown in Figures 1 to 3, it is also possible to form a large number of successive minute stepped portions that rise vertically by minute distances δV (e.g., 1 mm) for every minute distance δL (e.g., 10 mm) in the direction X in which the vehicle should travel.

The inclination angle ξ of the first inclined surface M2A with respect to the road surface SF is larger than the inclination angle θ of the second inclined surface M2B with respect to the road surface SF, and the inclination angle ξ of the first inclined surface M2A is set to be the complementary angle (ξ + θ = 90°) of the inclination angle θ of the second inclined surface M2B.
In Figure 5, the length of the attention warning groove M2 (the length of one span in the road direction) is indicated by the symbol L2, the length of the first inclined surface M2A is indicated by the symbol L21, the length of the second inclined surface M2B is indicated by the symbol L22, and the distance between adjacent attention warning grooves M2 in the road direction is indicated by the symbol I.
The cutting direction C2 of the warning groove M2 by the road surface cutting machine 100 (FIG. 7) is the road surface width direction (the direction of the arrow C2 or the opposite direction) as shown in FIG. 6. The boundary between the first inclined surface M2A and the second inclined surface M2B is indicated by the dashed line BD2 in FIG. 2.
5 and 6, the attention grooves M2 are formed in two places in succession in the running direction X of the vehicle, but more attention grooves M2 can be provided in succession. The length of the attention grooves M2 in the road width direction and the number of attention grooves M2 are determined by the conditions of the road surface on which the attention grooves M2 are to be constructed and various construction conditions.

The attention groove M2 of the second embodiment shown in Figures 5 and 6 has the same effect as the attention groove M1 of the first embodiment shown in Figures 1 to 4. That is, after the wheel W of a vehicle traveling in the normal traveling direction X reaches the start point of the attention groove M2, it jumps over the first inclined surface M2A (the deepest part of the first inclined surface M2A) due to the inertia of traveling and lands on the area of the second inclined surface M2B ahead in the traveling direction X. After that, the vehicle rises up the second inclined surface M2B of the attention groove M2 to reach the road surface SF and heads toward the start point of the next attention groove M1.
Here, since the depth dimension of the landing point on the second inclined surface M2B in the forward direction of travel X is much shorter than the depth dimension D2 at the deepest part of the first inclined surface M2A, the impact on the wheel W (which lands on the second inclined surface M2B in the forward direction of travel X) is relatively small, and the impact felt by the driver is also relatively small. Furthermore, the impact received by the vehicle passing through the attention warning groove M2 and the devices attached to the vehicle are also small, and the possibility of damage is low.

On the other hand, in the case of a vehicle traveling in the opposite direction Y from the normal traveling direction, the wheels W travel along the second inclined surface M2B of the attention groove M2, and immediately after reaching the lowest point of the second inclined surface M2B (the point of depth dimension D2), collide with the first inclined surface M2A of the attention groove M2. The impact felt by the driver traveling in the wrong direction at the time of the collision is much greater than that felt when traveling in the normal traveling direction X. In addition, the vertical component of the impact force when colliding with the first inclined surface M2A causes the vehicle to jump upward and rise above the road surface SF.
Therefore, the step when a wrong-way car goes over the attention groove M2 is equal to the depth D2 of the attention groove M2 plus the distance between the highest jumped-up position and the road surface SF. In addition to the impact of colliding with the first inclined surface M2A, the impact when going over the step of the depth D2 of the attention groove M2 plus the distance between the highest jumped-up position and the road surface SF is added, so the driver of the wrong-way car feels a very large impact, and by combining this sensation with signs installed on the side of the road and no entry marks painted on the attention groove, the driver can reliably recognize that he is "going the wrong way" with respect to the direction of travel.
As for other configurations and effects, the attention drawing groove M2 in FIGS. 5 and 6 is similar to the attention drawing groove M1 in FIGS.

Next, an embodiment of the road cutting machine of the present invention will be described with reference to FIGS.
7 showing an overview of the road surface cutting machine, the road surface cutting machine according to the embodiment generally designated by reference numeral 100 has drive wheels 1 and guide wheels 2 on the bottom of a vehicle body 6, and the drive wheels 1 and guide wheels 2 form a traveling device for moving the road surface SF in the road surface cutting machine 100. In FIG. 7, the traveling direction of the road surface cutting machine 100 is indicated by an arrow K.

Although not shown in Figure 7, the guide wheels 2, which are rear wheels, are provided at both ends of the road milling machine 100 in the vehicle width direction (direction perpendicular to the paper surface of Figure 7), and a rotary cutting device 3 (cutting device: cutter drum) for cutting grooves is provided inside the guide wheels 2 (the area between the guide wheels 2, 2 at both ends in the vehicle width direction). The rotary cutting device 3 is configured in a roughly cylindrical shape (see Figure 12).

The rotary cutting device 3 is a conventionally known device having a number of cutting bits provided on its surface, and is rotated by a drive device (not shown).
7, the rotation shaft of the rotary cutting device 3 is fixed to the vehicle body 6. Therefore, the position of the rotary cutting device 3 is always constant with respect to the vehicle body 6, and the rotary cutting device 3 does not move relative to the vehicle body 6. However, to avoid complication of description, this specification may use expressions such as "raising the rotary cutting device 3" and "lowering the rotary cutting device 3."
The guide wheel 2 is rotatably supported at a tip 7A of a link 7 by a guide wheel rotation shaft 2A, and the other end 7B of the link 7 is supported at a tip of a rod 8A of a hydraulic cylinder mechanism 8.
The cylinder mechanism 8 has a cylinder 8B (cylinder body) and a rod 8A, but both the cylinder mechanism and the cylinder (body) may be collectively referred to as the cylinder 8.
The link 7 is rotatably supported by a link rotation shaft 7C on a bracket 9 fixed to the vehicle body 6. Details of how the hydraulic cylinder mechanism 8 moves the bracket 9 and the guide wheel 2 will be described later with reference to Figs.

As the rod 8A of the hydraulic cylinder mechanism 8 extends and retracts, the link 7 rotates about the link rotation shaft 7C, lowering and raising the guide wheel 2. More specifically, when the rod 8A extends, the link 7 rotates counterclockwise about the link rotation shaft 7C, lowering the guide wheel 2, so that the vehicle body 6 and the rotary cutting device 3 relatively rise and move away from the ground (road surface SF).
On the other hand, when the rod 8A contracts, the link 7 rotates clockwise about the link rotation shaft 7C to raise the guide wheel 2, so that the vehicle body 6 and the rotary cutting device 3 descend relatively to each other and cut the ground surface (road surface SF).

An encoder 4 (distance sensor), which is a device that detects the distance traveled by the road cutting machine 100, is provided near the guide wheel 2. When the drive wheel 1 rotates and the road cutting machine 100 travels, the guide wheel 2 rotates, and the rotation of the guide wheel 2 is detected by the encoder 4, thereby accurately measuring the distance traveled by the road cutting machine 100.
A control device 10 (control unit) is mounted on the vehicle body 6 of the road cutting machine 100 .
The control device 10 has a function of executing the control necessary for cutting the slope-like portion M1B by raising the rotary cutting device 3 vertically by a minute distance δV (e.g., 1 mm) for each minute distance δL (e.g., 10 mm) in the direction in which the road extends, for example, when cutting the warning groove M1 shown in Figures 1 to 4, and cutting a large number of minute stepped portions.

Next, a configuration for raising or lowering the rotary cutting device 3 will be described with reference to FIGS.
7, the rod 8A connected to a piston (not shown) is extended or retracted by supplying or discharging pressure oil to or from the hydraulic cylinder mechanism 8. When the guide wheel 2 rises or falls via the link 7, the rotary cutting device 3 rises or falls (relatively).
In order to control the ascent or descent of the rotary cutting device 3, a linear potentiometer 13 is provided as a measuring device for measuring the displacement (extension and diaphragm, height) of the rod 8A, as shown in Figs.
8 and 9, the linear potentiometer 13 is composed of a cylinder portion 13A fixed to a hydraulic cylinder 8B, and a rod-shaped portion 13B. One end of the rod-shaped portion 13B is fixed to a piston (not shown) in the hydraulic cylinder 8B and is thereby fixed to the rod 8A, and as the rod 8A expands and contracts, the rod-shaped portion 13B of the linear potentiometer 13 slides within the cylinder-shaped portion 13A.
The other end of the rod-shaped portion 13B is fixed to the link 7 near the location where the rod 8A is rotatably fixed to the link 7.

Here, the resistance value R of the linear potentiometer 13 changes depending on the dimension in which the rod-shaped portion 13B of the linear potentiometer 13 is housed within the cylinder-shaped portion 13A. Therefore, by measuring the resistance value R of the linear potentiometer 13, the dimension in which the rod-shaped portion 13B of the linear potentiometer 13 is housed within the cylinder-shaped portion 13A can be calculated, and the amount of extension and position of the rod 8A of the hydraulic cylinder 8 can be accurately determined.
Based on this principle, if the amount of extension and position of the rod 8A of the hydraulic cylinder 8 can be accurately determined by the linear potentiometer sensor 13, the vertical position of the guide wheel 2 can be accurately determined, and the vertical position of the vehicle body 6 and the vertical position of the rotary cutting device 3 can also be accurately determined.
As described above, the guide wheel 2 is connected to the rod 8A of the hydraulic cylinder 8 via the link 7. In Fig. 8, the vertical position Q1 of the guide wheel 2 during travel (when the rotary cutting device 3 is not cutting), the vertical position Q2 of the guide wheel 2 during the cutting of the warning groove (when the rotary cutting device 3 is cutting), and the vertical position Q3 of the guide wheel 2 in an intermediate state, neither during travel nor cutting, are shown. Corresponding to the vertical positions Q1, Q2, and Q3 of the guide wheel 2, the vertical positions of the rotary cutting device 3 are also different at the travel position, cutting position, and intermediate position. In Fig. 8, the guide wheel 2 (and the link 7) at the intermediate position Q3 is shown by a solid line, and the guide wheel 2 (and the link 7) at the travel position Q1 and the cutting position Q2 are shown by a dashed line.
The encoder 4 (distance sensor) is fixed to the vehicle body 6 side by a link mechanism (not shown), and the encoder 4 (distance sensor) is provided in the vicinity of the guide wheel 2 .

With reference to FIG. 10, a hydraulic circuit for supplying and discharging pressure oil to the hydraulic cylinder mechanism 8 will be described.
10, solenoid valves 12L, 12R (electromagnetic switching valves) are provided in pressure oil piping systems 11L, 11R that supply or discharge pressure oil from a hydraulic supply source 14 (including a hydraulic pump) to hydraulic cylinders 8L, 8R, respectively. The hydraulic cylinders 8L, 8R are provided to raise and lower the left and right guide wheels 2L, 2R, respectively.
The solenoid valves 12L and 12R are high-speed response valves, each having a three-port solenoid valve, and a check valve 15 and a throttle valve 16 are provided in the area closer to the hydraulic cylinder 8 than the solenoid valves 12L and 12R.
By installing solenoid valves 12L, 12R, which are fast response valves, in the pressure oil piping systems 11L, 11R, the amount of pressure oil supplied to the hydraulic cylinders 8L, 8R is accurately controlled, and as a result, the amount of vertical movement of the guide wheels 2L, 2R and the amount of lift or lowering of the rotary cutting device 3 are also controlled with high precision.

The measurement results from the encoder 4 (distance sensor) and the measurement results of the displacement amount of the rod 8A of the hydraulic cylinder 8 from the linear potentiometer 13 are sent to the control device 10. The control device 10 calculates the travel distance of the road surface cutting machine 100 based on the input measurement results from the encoder 4, and calculates and determines the vertical position of the guide wheels 2 and the vertical position of the rotary cutting device 3 based on the measurement results of the displacement amount of the rod 8A from the linear potentiometer 13.
Furthermore, the control device 10 controls an electromagnetic valve 12 (high-speed response valve) interposed in the pressurized oil piping system 11 based on the calculated traveling distance of the road surface cutting machine 100, thereby controlling the amount of pressurized oil supplied to the hydraulic cylinder 8 and adjusting the vertical position of the rotary cutting device 3 by controlling the displacement amount of the rod 8A of the hydraulic cylinder 8.
In the road cutting machine 100 shown in Figures 7 to 10, by combining a linear potentiometer 13 with an solenoid valve 12 (high-speed response valve) in the pressure oil piping system 11, the vertical position of the rotary cutting device 3 can be accurately adjusted (controlled) to a level (for example, in units of 1 mm) that was not possible with conventional technology. Therefore, when forming the sloped portion M1B shown in Figure 3, the vertical movement of the rotary cutting device 3 can be finely adjusted so that it rises vertically by a fine distance δV (for example, 1 mm) for every fine distance δL (for example, 10 mm) in the direction in which the vehicle should travel.

Next, a mode of cutting the warning groove M1 shown in FIGS. 1 to 4 using the road surface cutting machine 100 shown in FIGS. 7 to 10 will be described mainly with reference to FIG.
11, the road surface cutting machine 100 is caused to travel to a planned position where the attention warning groove M1 is to be formed. In step S1, it is determined whether the road surface cutting machine 100 has reached a planned formation position of the arc-shaped portion M1A of the attention warning groove M1.
When the road surface cutting machine 100 is made to travel to the planned formation position of the warning groove M1, the guide wheels 2 are set in the vertical position of the travelling position (position Q1 in FIG. 8 ), and the rotary cutting device 3 (at its lowest position) is made to travel in a state where it is positioned a predetermined distance above the road surface SF. At this time, the rotary cutting device 3 is not cutting the road surface SF.

In step S1, the determination as to whether the road surface cutting machine 100 has reached the planned formation position of the arc-shaped portion M1A of the attention groove M1 is made, for example, by the judgment of an operator on board the road surface cutting machine 100, but can also be made by other methods (for example, receiving information from a positioning satellite, etc.). Furthermore, it is also possible to set a start point for the attention groove formation control on the side closer to the planned formation position of the arc-shaped portion M1A of the attention groove M1, and determine whether the road surface cutting machine 100 has reached the planned formation position of the arc-shaped portion M1A of the attention groove M1 based on the distance traveled from the start point.
In step S1, if the road surface cutting machine 100 has reached the position where the arc-shaped portion M1A of the warning groove M1 is planned to be formed (step S1 is "Yes"), proceed to step S2, and if the road surface cutting machine 100 has not reached the position where the arc-shaped portion M1A of the warning groove M1 is planned to be formed (step S1 is "No"), proceed to step S3.

In step S2, the traveling of the road surface cutting machine 100 is stopped. Then, the process proceeds to step S4.
On the other hand, in step S3, the road surface cutting machine 100 continues traveling toward the attention-attracting groove M1. Then, the process returns to step S1 (a loop in which step S1 is "No").
Steps S4 and S5 are steps for cutting the arc-shaped portion M1A of the attention groove M1. In step S4, the rotary cutting device 3 is rotated and lowered while the road surface cutting machine 100 is stopped. In step S4, the rotary cutting device 3 is rotated and lowered to cut the arc-shaped portion M1A of the attention groove M1. As shown in Figs. 1 and 2, the depth dimension of the arc-shaped portion M1A is D1 (predetermined depth), and the "cutting" in step S4 is performed until the cutting depth of the rotary cutting device 3 reaches the dimension D1 (predetermined depth) shown in Figs. 1 and 2 from the road surface SF (ground surface). Note that the predetermined depth D1 is set to 50 mm or less as described above.

In step S5, it is determined whether the cutting depth of the rotary cutting device 3 has reached a predetermined depth D1. This determination is made by calculating and determining the vertical position of the rotary cutting device 3 based on the measurement result of the displacement amount of the rod 8A of the cylinder 8 by the linear potentiometer 13.
In step S5, if the cutting depth of the rotary cutting device 3 reaches the predetermined depth D1 (step S5 is "Yes"), it is determined that cutting of the arc-shaped portion M1A is completed, and the process proceeds to step S6.
On the other hand, if the cutting depth of the rotary cutting device 3 has not reached the predetermined depth D1, the process returns to step S4, and cutting of the arc-shaped portion M1A by the rotary cutting device 3 continues (a loop in which step S5 is "No").

Steps S6 to S11 are processes for cutting the slope-like portion M1B following the arc-like portion M1A, and each time the road surface cutting machine 100 advances in the direction X in which the vehicle should travel by an infinitesimal distance δL (e.g., 10 mm, see FIG. 3), the rotary cutting device 3 is raised in the vertical direction by an infinitesimal distance δV (e.g., 1 mm, see FIG. 3) to form the fine, stepped slope-like portion M1B.
Although not clearly shown, minute distances δL (X direction) and δV (vertical direction) that determine the gradient and shape of the slope portion M1B are set in the control device 10 at a stage prior to step S1.

In step S6, the road cutting machine 100 is advanced forward (direction X).
In step S7, it is determined whether the road cutting machine 100 has advanced a minute distance δL (for example, 10 mm) from the start of step S6. This determination is made by calculating the travel distance of the road cutting machine 100 based on the measurement results of the encoder 4.
If the result of the determination in step S7 is that the road surface cutting machine 100 has advanced by the minute distance δL (step S7 is "Yes"), the process proceeds to step S8. If the road surface cutting machine 100 has not advanced by the minute distance δL, the process returns to step S6, and the road surface cutting machine 100 continues to advance (a loop in which step S7 is "No").

In step S8 (when the road surface cutting machine 100 has advanced by the minute distance δL), the rotary cutting device 3 is raised. At that time, the solenoid valve 12 (high-speed response valve) installed in the pressure oil piping system 11 is controlled to control the amount of pressure oil supplied to the hydraulic cylinder 8, and the amount of displacement of the rod 8A of the hydraulic cylinder 8, thereby adjusting the vertical position of the rotary cutting device 3.
In step S9, it is determined whether the rotary cutting device 3 has risen by a minute distance δV (for example, 1 mm). This determination is made by calculating and determining the vertical position of the rotary cutting device 3 based on the measurement result of the displacement amount of the rod 8A of the cylinder 8 by the linear potentiometer 13.
In step S9, if the rotary cutting device 3 has risen by the minute distance δV (step S9 is "Yes"), the process proceeds to step S10. On the other hand, if the rotary cutting device 3 has not risen by the minute distance δV, the process returns to step S8, and the rotary cutting device 3 continues to rise (a loop in which step S9 is "No").
In step S10 (when the rotary cutting device 3 has risen by the minute distance δV), the rise of the rotary cutting device 3 is stopped.

The process in steps S6 to S10, i.e., the process of cutting the minute stepped portion by raising the rotary cutting device 3 by an infinitesimal distance δV every time the rotary cutting device 3 advances by the infinitesimal distance δL, is repeated many times in succession until the road surface cutting machine 100 advances a predetermined length (e.g., 1 m) in the direction X in which the vehicle should advance on the sloped portion M1B. By repeating the process in steps S6 to S10 many times in succession, a smooth sloped portion M1B is cut.
In the illustrated embodiment, when the rotary cutting device 3 (its cutting depth) reaches a height above the road surface SF, the length of the sloped portion M1B in the direction in which the vehicle must travel is preset to a required specified length (for example, 1 m), so that cutting of the sloped portion M1B is completed once the road surface cutting machine 100 has traveled the specified length.

In step S11, it is determined whether the cutting depth of the rotary cutting device 3 has reached a predetermined height above the road surface SF. This determination is made by calculating and determining the vertical position of the rotary cutting device 3 based on the measurement result of the displacement amount of the rod 8A of the cylinder 8 by the linear potentiometer 13. The vertical position of the rotary cutting device 3 can also be determined by using the cumulative displacement amount from the cutting depth of the rotary cutting device 3 at the start of step S6 (i.e., the predetermined depth D1) as the displacement amount of the rod 8A of the cylinder 8 measured by the linear potentiometer 13.
Alternatively, it is also possible to calculate the travel distance of the road cutting machine 100 based on the measurement results of the encoder 4, and perform the judgment in step S11 depending on whether the road cutting machine 100 has traveled a predetermined length (for example, 1 m).
In step S11, if the cutting depth of the rotary cutting device 3 reaches a predetermined height above the road surface SF (step S11 is "Yes"), it is determined that cutting of the slope-shaped portion M1B is completed, and the process proceeds to step S12.
On the other hand, if the cutting depth of the rotary cutting device 3 has not reached the predetermined height above the road surface SF, the process returns to step S6 and continues cutting the slope-shaped portion M1B (a loop in which step S11 is "No").

In step S12 (when the cutting depth of the rotary cutting device 3 reaches a predetermined height above the road surface SF), the rotary cutting device 3 is raised to a non-cutting position (traveling position Q1 in FIG. 8) relative to the body 6 of the road surface cutting machine 100. Then, in this state, the road surface cutting machine 100 is caused to travel. Then, the process proceeds to step S13.
In step S13, it is determined whether to end the cutting work of the attention groove M1 or continue the cutting work of the attention groove M1. For example, when the road surface cutting machine 100 runs once, the attention groove M1 with the width dimension of the cutting device 3 is cut. Although not shown, when the width dimension of the cutting device 3 is smaller than the width dimension of the road, the start points of the attention groove M1 are aligned, and the attention groove M1 is cut multiple times while moving the road surface cutting machine 100 in the road width direction, taking into consideration the necessary overlap amount (the overlap amount in the road width direction when the attention groove M1 is cut again adjacent to the road width direction). In this way, when cutting the attention groove M1 by moving the road surface cutting machine 100 in the road width direction, "No" is selected in step S13, and steps S1 and after are repeated.
The judgment in step S13 is made, for example, by an operator riding on the road surface cutting machine 100 based on the construction plan for the warning groove M1.
As a result of the determination in step S13, when the cutting operation of the warning groove M1 is to be ended (step S13 is "Yes"), the control ends.
If the cutting work of the attention warning groove M1 is to be continued (step S13 is "No"), the process returns to step S1, and the same work as steps S1 to S11 is performed at a predetermined position in the X direction (forward direction) of the cut attention warning groove M1.

According to the first embodiment of the attention-attention groove M1 including the arc-shaped portion M1A and the slope-shaped portion M1B, the wheels of a vehicle traveling in the normal traveling direction do not get stuck in the arc-shaped portion M1A at the front end in the traveling direction due to the inertia of traveling, but jump over the arc-shaped portion M1A and land in the forward area of the slope-shaped portion M1B in the normal traveling direction X. The depth dimension of the slope-shaped portion M1B in the forward area in the traveling direction X relative to the road surface SF is much shorter than that of the arc-shaped portion M1A, and the slope-shaped portion M1B is a smooth slope, so that the impact on the wheels is relatively small and the impact felt by the driver is also relatively small. Furthermore, the impact received by the vehicle and the equipment installed in the vehicle is also small, and the possibility of damage is low.
On the other hand, in the case of a vehicle traveling in the opposite direction Y to the normal traveling direction X, the wheels travel on the slope-shaped portion M1B of the attention groove M1, and collide with the arc-shaped portion M1A of the attention groove M1 immediately after reaching the bottom. The impact felt by the driver at the time of the collision is much greater than when traveling in the normal traveling direction X. In addition, the vertical component of the impact force of the collision causes the vehicle to jump upward and rise above the road surface SF. Therefore, the step is a distance (D1 + J1) obtained by adding the distance J1 that jumped up to above the road surface SF to the depth D1 of the attention groove. In addition to the above impact, the impact of going over the step of the distance (D1 + J1) is added to the vehicle traveling in the opposite direction, so the driver of the vehicle traveling in the opposite direction feels a very large impact, and can reliably recognize that the vehicle is "traveling in the opposite direction" from the traveling direction due to the physical sensation. If the driver continues to drive the wrong way, he or she will repeatedly experience the extremely large shocks described above. This physical sensation, combined with signs posted on the side of the road and no entry marks painted on warning grooves, will further heighten the driver's awareness that the driver is driving the wrong way.

According to the road cutting machine 100 or road cutting method of the embodiment shown in the figure, a solenoid valve 12 (high-speed response valve) is interposed in a pressure oil piping system 11 that supplies or discharges pressure oil to a hydraulic cylinder 8 that moves a rotary cutting device 3 in a vertical direction, and a linear potentiometer 13 that measures the displacement of a rod 8A of the hydraulic cylinder 8 is provided. The control device 10 accurately determines the vertical position of the cutting device 3 based on the measurement result of the linear potentiometer 13 that measures the displacement of the rod 8A, and controls the solenoid valve 12 of the pressure oil piping system 11 based on the measurement result of the encoder 4 (distance sensor) to control the amount of pressure oil supplied to the hydraulic cylinder 8, thereby adjusting the vertical position of the cutting device 3 with high accuracy. Therefore, the extension or contraction amount of the hydraulic cylinder 8, i.e., the vertical position of the cutting device 3, is controlled with high accuracy (for example, in millimeters), and the cutting edge position of the cutting tool of the cutting device 3 is also controlled with high accuracy.
For example, when cutting the sloped portion M1B of the attention-attracting groove M1, the cutting device 3 can be raised vertically by a minute distance δV (e.g., 1 mm) for each minute distance δL (e.g., 10 mm) in the direction in which the road extends, to cut a minute stepped portion. By repeatedly cutting such minute stepped portions a number of times in succession over a predetermined length (e.g., 1 m) in the direction in which the vehicle should travel, a smooth sloped portion M1B can be cut.

In addition, by using the road cutting machine 100 or road cutting method in the illustrated embodiment, the position of the cutting edge of the cutting tool of the cutting device 3 corresponding to the traveling distance of the road cutting machine 100 can be accurately determined, and the road surface can be cut accurately, so that the slope-shaped portion M1B is also smooth and fine irregularities are reduced.
With such a smooth slope portion M1B, when traveling in the normal traveling direction X, the impact when the wheels jump over the arc-shaped portion M1A and land on the slope portion M1B is extremely small, so that the impact received by the vehicle and the driver is also small, and there is little risk of damage to devices attached to the vehicle.

Next, with reference to Figures 12 to 15, an embodiment of cutting the warning groove M2 shown in Figures 5 and 6 using the road surface cutting machine 100 shown in Figures 7 to 10 will be described.
As described above, when cutting the warning groove M1, the traveling direction of the road cutting machine 100 is the extension direction of the road, but cutting of the warning groove M2 shown in Figures 5 and 6 is carried out while the road cutting machine 100 is traveling in the width direction C2 of the road (or the opposite direction).
12, the rotary cutting device 3 of the roughly cylindrical shape in the road surface cutting machine 100 has its rotation axis 3S inclined with respect to the road surface SF. The inclination angle of the rotary cutting device 3's rotation axis 3S with respect to the road surface SF is set equal to the inclination angle θ (see FIG. 5) of the second inclined surface M2B of the attention groove M2 with respect to the road surface SF, and the inclination angle of the end face 3A on the first inclined surface M2A side of the rotary cutting device 3 with respect to the road surface SF is set equal to the inclination angle ξ of the first inclined surface M2A with respect to the road surface SF (the complementary angle of the inclination angle θ, ξ + θ = 90°: see FIG. 5).
In FIG. 12, the axial length of the rotary cutting device 3 is indicated by the symbol L3, and the attention-attracting groove M2 to be cut is indicated by a virtual line (dotted line).

Then, from the state shown in Figure 12, the rotary cutting device 3 is lowered to a predetermined cutting depth D2 to cut the road surface SF while the road surface cutting machine 100 runs in the width direction of the road (direction perpendicular to the paper surface of Figure 12), thereby forming a warning groove M2 consisting of a first inclined surface M2A and a second inclined surface M2B shown in Figures 5 and 6, as shown in Figure 13.
The depth of the deepest part of the formed attention drawing groove M2 is dimension D2, and the length of the second inclined surface M2B is equal to the axial length L3 of the rotary cutting device 3. Here, the depth D2 of the deepest part is set to 50 mm or less.
As is clear from referring to Figure 13, the relationship shown in the following equation holds between the inclination angle θ of the second inclined surface M2B with respect to the road surface SF, the depth D2 of the deepest part of the warning groove M2, and the length L3 of the second inclined surface M2B (= the axial length of the rotary cutting device 3).
θ=arcsin(D2/L3)
In order to avoid complexity, only the rotary cutting device 3 is shown in Figures 12 and 13, and the road surface cutting machine 100 and the like are omitted. In Figures 12 and 13, the rotary cutting device 3 is inclined at an inclination angle θ (the inclination angle of the second inclined surface M2B with respect to the road surface SF) as described above, but the road surface cutting machine 100 supporting the rotary cutting device 3 travels in a horizontal state with respect to the road surface SF.

As explained with reference to Figures 12 and 13, the process of lowering the rotary cutting device 3 while tilted relative to the road surface SF is repeated twice (or multiple times) for the same warning groove M2. This will be explained with reference to Figures 14 and 15.
In FIG. 14, the road surface cutting machine 100 is caused to travel in the width direction (arrow F1) of a road having a width dimension B2, and the rotary cutting device 3 cuts a warning groove M2-1.
Here, if the traveling direction of the road surface cutting machine 100 (not shown) is the direction of arrow F1 and the length of the road surface cutting machine 100 in the F1 direction is longer than the length L4 from the end M2E of the warning groove M2-1 to the road end RE, when cutting the same warning groove M2, it is necessary to cut the warning groove M2-1 shown in Figure 14 as a first step, and then cut the warning groove M2-2 as shown in Figure 15 as a second step.
When cutting the second stage of the attention groove M2-2 shown in Figure 15, the road surface cutting machine 100 (rotary cutting device 3) is driven in the direction of the arrow F2, which is opposite to the first stage, to perform cutting. The symbol M2W indicates the overlapping portion of the attention groove M2-1 and the attention groove M2-2.
However, the number of times that the attention groove M2 is repeatedly cut may be three or more.
14 and 15 each show an example in which two rows of attention-attention grooves M2 (M2-1 and M2-2) are cut in the traveling direction of the road.

In the second embodiment of the present invention, the wheels of a vehicle traveling in the normal traveling direction also fly over the first inclined surface M2A and the deepest part of the groove, and land on the area of the second inclined surface M2B in front of the normal traveling direction X. The depth dimension of the area of the second inclined surface M2B in front of the normal traveling direction X on the road surface SF is much shorter (shallower) than the depth dimension D2 of the deepest part, so the impact felt by the driver is relatively small. The impact received by the vehicle and the equipment installed on the vehicle is also small, and the possibility of damage is low.
On the other hand, in the case of a vehicle traveling in the opposite direction Y to the normal traveling direction X, the wheels travel on the second inclined surface M2B, and when they reach the deepest part, the inclination angle ξ of the first inclined surface M2A with respect to the road surface SF is relatively large, so the wheels collide with the first inclined surface M2A. The impact felt by the driver at the time of the collision is much greater than when traveling in the normal traveling direction X. In addition, the vertical component of the impact force of the collision causes the vehicle to jump upward, so the step when the vehicle goes over the attention groove M2 is the sum of the depth D2 of the deepest part and the distance it jumps up to above the road surface SF. In addition to the above impact, the impact of going over the step is added to the vehicle traveling in the opposite direction, so the driver of the vehicle traveling in the opposite direction feels a very large impact, and by combining this sensation with signs installed on the side of the road and no entry marks painted on the attention grooves, the driver can reliably recognize that the vehicle is "traveling in the opposite direction" to the traveling direction.
Here, the cutting of the warning groove M2 having the first and second inclined surfaces M2A, M2B can be performed by running the road surface cutting machine 100 in the width direction of the road.

Please note that the illustrated embodiments are merely examples and are not intended to limit the technical scope of the present invention.

1: Drive wheel 2: Guide wheel 3: Cutting device (rotary cutting device)
4...Encoder (distance sensor)
6: Vehicle body 7: Link 8: Hydraulic cylinder 8A: Rod 9: Bracket 10: Control device 11: Pressure oil piping system 12: Solenoid valve (high-speed response valve)
13: Linear potentiometer 100: Road cutting machine M1, M2: Attention groove M1A: Arc-shaped portion M1B: Slope-shaped portion M2A: First inclined surface M2B: Second inclined surface SF: Road surface

Claims (2)

When a wheel (W) of an automobile traveling in the direction (X) in which it should travel reaches the start point (P1) of the caution groove (M1), it jumps over the arc-shaped portion (M1A) without getting stuck in the arc-shaped portion (M1A) due to the inertia of the travel, and lands in a region (P2) in front of the normal traveling direction (X) on the slope-shaped portion (M1B). The depth dimension of the region (P2) where the wheel (W) lands relative to the road surface (SF) is shorter than the depth dimension (D1) of the deepest part (D1) of the arc-shaped portion (M1A). Furthermore, the wheel (W) of an automobile traveling in the opposite direction (Y) to the normal traveling direction collides with the arc-shaped portion (M1A) immediately after reaching the bottom (P5) of the slope-shaped portion (M1B), and jumps upward due to the vertical component of the impact force when it collides with the arc-shaped portion (M1A), and rises above the road surface (SF). In a road surface cutting method for cutting a caution groove (M1), the step when the vehicle rises up and goes over the caution groove (M1) is a distance obtained by adding a distance (J1) that rises above the road surface (SF) to the depth (D1) of the caution groove (M1), and in order to cause a driver of a vehicle traveling in the wrong direction to receive a large impact, the caution groove (M1) has an arc-shaped portion (M1A) and a slope-shaped portion (M1B), the arc-shaped portion (M1A) is located at the front end of the direction (X) in which the vehicle should move and is formed to a predetermined cutting depth (D1), and the slope-shaped portion (M1B) is composed of an inclined surface that rises continuously from the arc-shaped portion (M1A) so as to reach the road surface (SF), and the slope is composed of a large number of successive minute step-shaped portions that rise by a minute distance (δV) in the vertical direction for every minute distance (δL) in the direction (X) in which the vehicle should move,
A road surface cutting machine (100) is run in the direction in which the road extends to cut a warning groove (M1);
A process of lowering a cutting device (3) of a road surface cutting machine (100) from a road surface (SF) to a predetermined cutting depth (D1) to cut a circular arc-shaped portion (M1A) at a front end of a warning groove (M1);
The method includes a step of cutting a slope-shaped portion (M1B) that is composed of an inclined surface that rises so as to reach a road surface (SF) continuously from the arc-shaped portion (M1A),
This road surface cutting method is characterized in that in the process of cutting the slope-like portion (M1B), a cycle of raising the cutting device (3) vertically by a minute distance (δV) for each minute distance (δL) in the direction (X, Y) in which the road (SF) extends and cutting a minute stepped portion is repeated many times in succession over a predetermined length in the direction (X) in which the vehicle should proceed. A wheel (W) of an automobile traveling in a direction (X) in which the automobile should travel reaches a start point (P1) of a caution groove (M1), and due to the inertia of the travel, the wheel (W) does not get stuck in the arc-shaped portion (M1A), but jumps over the arc-shaped portion (M1A), and lands on a slope-shaped portion (M1B) in an area (P2) ahead of the normal traveling direction (X). The depth dimension of the area (P2) where the wheel (W) lands with respect to the road surface (SF) is The slope (P5) of the sloped portion (M1B) is shorter than the depth (D1) of the deepest part (D1) of the arc-shaped portion (M1A), and the wheel (W) of the vehicle traveling in the opposite direction (Y) to the normal traveling direction collides with the arc-shaped portion (M1A) immediately after reaching the lowest point (P5) of the sloped portion (M1B). The wheel (W) jumps upward due to the vertical component of the impact force when colliding with the arc-shaped portion (M1A) and flies upward above the road surface (SF). a road surface milling machine (100) for milling a warning groove (M1), the road surface milling machine (100) having an arc-shaped portion (M1A) and a slope-shaped portion (M1B) for causing a driver of a wrong-way vehicle to receive a large impact when the driver of the wrong-way vehicle rises above the road surface (SF) and goes over the warning groove (M1), the arc-shaped portion (M1A) is located at the front end of the direction (X) in which the vehicle should move and is formed at a predetermined cutting depth (D1), the slope-shaped portion (M1B) is composed of an inclined surface that is continuous with the arc-shaped portion (M1A) and rises to reach the road surface (SF), the inclined surface being composed of a large number of successive minute step-shaped portions that rise by a minute distance (δV) in the vertical direction for every minute distance (δL) in the direction (X) in which the vehicle should move,
A road surface cutting machine (100) including a traveling device (1, 2) for moving on a road surface (SF), a cutting device (3) for cutting the road surface, a distance sensor (4) for measuring a traveled distance, and a control device (10) to which the measurement results of the distance sensor (4) are inputted,
The hydraulic cylinder (8) moves the cutting device (3) in a vertical direction, a pressure oil piping system (11) supplies or discharges pressure oil to the hydraulic cylinder (8), a solenoid valve (12) is provided in the pressure oil piping system (11), and a sensor (13) measures the amount of displacement of a rod (8A) connected to a piston of the hydraulic cylinder (8),
The control device (10) has a function of determining the vertical position of the cutting device (3) based on the measurement result of the sensor (13) that measures the displacement amount of the rod (8A);
The road cutting machine (100) has a function of controlling the amount of pressurized oil supplied to the hydraulic cylinder (8) by controlling an electromagnetic valve (12) in a pressurized oil piping system (11) based on the measurement results of a distance sensor (4), thereby adjusting the vertical position of the cutting device (3).

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