Vehicle stop device

Abstract

To provide a vehicle stopping device capable of effectively stopping a vehicle entering obliquely.SOLUTION: The present invention relates to a vehicle stop device 1 for bringing a vehicle to an emergency stop, including a vehicle abutment means 2 erected upward from a grounding portion at a lower end, and a plurality of vehicle bottom entry means 10 each provided with a slope surface inclined downward toward the vehicle, wherein the plurality of vehicle bottom entry means 10 are radially arranged so as to be spaced apart from each other toward a distal end direction. Since the vehicle bottom intruding parts 10 are radially provided, even when the vehicle intrudes from an angle other than the front of the vehicle stopping apparatus 1, any of the vehicle bottom intruding parts 10 can bite into the vehicle bottom according to the traveling direction of the vehicle. As a result, the engagement is prevented from being released until the vehicle stops, and the vehicle can be effectively stopped.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a vehicle stopping device. [Background technology]

[0002] When road construction work or the like is being carried out, vehicle stopping devices are installed to prevent vehicles from entering work areas. When a vehicle attempts to enter a work area where vehicle entry is restricted and braking is not possible in time, the vehicle stops by running onto a device that increases friction resistance with the road surface. An example of such a vehicle stopping device is the vehicle stopping device described in Patent Document 1.

[0003] Another conventional vehicle stopping device is shaped like the Greek letter λ, as shown in Figure 3. This vehicle stopping device has a plurality of vehicle bottom penetration means called arms with sloped surfaces that slope downward toward the vehicle, and a vehicle abutment means called a mast that stands upright from the ground, and has a structure in which a plurality of arms are arranged in parallel toward the vehicle. The roles of the conventional vehicle stopping device 100 include lane change guidance, preventing vehicles from entering, and ensuring the safety of workers. After the vehicle comes into contact with the arm, this conventional vehicle stopping device 100 lifts the front part of the vehicle with the arm and moves together with the vehicle, absorbing the kinetic energy of the vehicle and forcing it to a stop through braking work caused by friction between the friction member at the bottom of the brake body and the road surface.

[0004] The λ-type vehicle stopping device safely and forcibly brakes and stops vehicles that mistakenly enter road construction sites where lane restrictions are in place, but it is preferable that it also have sufficient braking force for vehicles entering at an angle (oblique entry vehicles).In order to reduce accident damage to construction site workers and vehicle occupants and to further expand the use of brakes, it is necessary to consider the optimal brake structure, shorten the braking distance, and respond to different entry directions (oblique, offset). [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Utility Model Registration No. 3246010

[0006] [Non-Patent Document 1] internet<URL:https: / / www.jstage.jst.go.jp / article / jjsem / 20 / 1 / 20_45 / _pdf / -char / ja> Summary of the Invention [Problem to be solved by the invention]

[0007] The present invention was invented in consideration of the above circumstances, and aims to provide a vehicle stopping device that is effective in stopping a vehicle even in the event of a collision that is angled relative to the front of the vehicle stopping device, by examining the optimal structure of the braking body in order to improve the braking performance of the conventional vehicle stopping device 100. [Means for solving the problem]

[0008] In order to solve the above problems, the present invention has the following configuration: A vehicle stopping device characterized by having a vehicle abutment means erected upward from the ground contact portion at the lower end, and a plurality of vehicle bottom penetration means provided with a sloped surface inclined downward toward the vehicle, and the plurality of vehicle bottom penetration means arranged radially with increasing spacing toward the tip.

[0009] In addition, in the vehicle stopping device of the present invention, the multiple vehicle bottom intrusion means are arranged at the same angle around a virtual reference point in a plan view and are fixed to each other.

[0010] In the vehicle stopping device of the present invention, the vehicle contact means is formed by a plurality of steel members arranged in parallel and connected to one another. [Effects of the Invention]

[0011] The structure of the present invention, in which the vehicle bottom penetration means (arms) are arranged in a fan shape, has the advantage of being able to brake and stop vehicles entering at an angle in response to a wide range of entry angles, compared to conventional conventional vehicle stopping devices. [Brief explanation of the drawings]

[0012] [Figure 1] 1 is an external perspective view of a vehicle stopping device according to an embodiment of the present invention; [Figure 2] 1 is a plan view of a vehicle stopping device according to an embodiment of the present invention; [Figure 3] FIG. 1 is an external view of a conventional vehicle stopping device. [Figure 4] FIG. 2 is an explanatory diagram of a vehicle model used in a collision experiment. [Figure 5] FIG. 1 is an explanatory diagram of a collision experiment device. [Figure 6] 1 is a side view showing the behavior of a conventional vehicle stopping device during a vehicle collision. [Figure 7] 1A and 1B are a front view and a plan view showing the behavior of a conventional vehicle stopping device at the time of a vehicle collision. [Figure 8] FIG. 1 is an explanatory diagram of an experimental model of a conventional vehicle stopping device. [Figure 9] FIG. 1 is an explanatory diagram of an experimental model of a vehicle stopping device in which arms are arranged in a fan shape. [Figure 10] FIG. 10 is an explanatory diagram of the approach angle and travel distance of the model vehicle in the experiment. [Figure 11] FIG. 1 is an explanatory diagram showing the braking behavior of a conventional model for a vehicle that enters at an angle. [Figure 12] This is an enlarged view of the braking behavior of a conventional model in the horizontal plane. [Figure 13] FIG. 10 is an explanatory diagram illustrating a case where the conventional model is unable to stop the model vehicle. [Figure 14] FIG. 10 is an explanatory diagram showing the braking behavior of a new model. [Figure 15]FIG. 10 is an explanatory diagram showing an enlarged view of the braking behavior of the new model in a horizontal plane. [Figure 16] FIG. 10 is an explanatory diagram showing the braking behavior of a new model when a vehicle enters at an angle. [Figure 17] 1 is a graph showing the average braking distance of a conventional model and the average braking distance of a new model. [Figure 18] This is a graphic that reproduces the behavior of the new model confirmed in collision tests. [Figure 19] 10 is a graph showing the X-direction distance and the Y-direction distance of a conventional model and the X-direction distance and the Y-direction distance of a new model. [Figure 20] FIG. 10 is an explanatory diagram showing a logical model for calculating braking distance. [Figure 21] 1 is a graph plotting theoretical braking distances and average braking distances obtained through experiments. DETAILED DESCRIPTION OF THE INVENTION

[0013] An embodiment of the present invention will now be described with reference to the drawings. Fig. 1 is an external perspective view of a vehicle stopping device 1 according to this embodiment, and Fig. 2 is a plan view of the vehicle stopping device 1. The vehicle stopping device 1 has a vehicle abutment means 2 called a mast, and a vehicle bottom penetration means 10 consisting of a plurality of arms 13 formed from square steel material.

[0014] The vehicle abutment means 2 is formed, for example, by three vertical elements 3 arranged in parallel and a plurality of connecting elements 4 that firmly connect the vertical elements 3. Since the vertical elements 3 are the parts that come into contact with the vehicle, they are formed from high-strength square steel pipes to provide sufficient strength against impacts and loads. The connecting elements 4 are rod-shaped members formed from steel pipes or solid steel material, and by firmly connecting the vertical elements 3 by welding or the like, a highly rigid vehicle abutment means 2 is formed.

[0015] In this embodiment, the total length of the vertical elements 3 constituting the vehicle contact means 2 is approximately 1 m, and the total length of the connecting elements 4 is also approximately 1 m. In other words, the vehicle contact means 2 is configured as a lattice-shaped rigid body of approximately 1 m square, and has a structure that will not easily break even if a vehicle comes into contact with it. A contact member 5 for contacting the road surface is attached to the lower end of the vertical element 3. The contact member 5 is formed as a metal fitting with a concave cross section, having a bottom wall 6 and side walls 7 erected on the left and right sides of the bottom wall 6, and the left and right side walls 7 are rotatably attached to the lower end of the vertical element 3, so that the bottom wall automatically adjusts to make surface contact with the road surface even if the contact member 5 is tilted in the front-to-rear direction. Friction means 8 made of rubber or the like that increases friction with the road surface is attached to the bottom wall.

[0016] The arm 13 is formed from a high-strength square steel pipe to provide sufficient strength against impacts and loads. The arm 13 has a base 11 on one end fixed to a connecting portion 12 provided on the vehicle contact means 2, and is shaped to have a slope portion 15 that slopes downward from the base 11 to the tip. The bottom of the tip is formed as a flat surface with an angle adjusted so that it comes into contact with the road surface, and a friction means 14 made of rubber or the like that increases friction with the road surface is attached to the bottom.

[0017] The multiple arms 13 are arranged radially from the base 11 toward the tip to form a fan shape. For example, adjacent arms 13 are arranged at angles of 10 degrees in a plan view seen from above. The bases 11 of the arms 13 are connected to each other at connecting portions 12 and connected to the vehicle contact means 2. The connecting portion 12 has two semicircular plates 20, 21 whose semicircular diameter portions are fixed to a fixing means 9 which also serves as a connecting element of the vehicle abutment means 2, and the bundled base portion 11 is firmly fixed by being sandwiched between the semicircular plates 20, 21 at the top and bottom.

[0018] Each arm 13, which is arranged at an angle radially from the joint 12 as the center, is connected to an adjacent arm 13 at approximately the middle of the downwardly sloping slope 15 by a connecting member 30. The connecting member 30 is made of a round steel bar that has been curved to match the curvature of the deployed arm, and is positioned so as to penetrate the side of each arm 13 and is firmly fixed in place. The connecting member 30 has the function of maintaining the spacing between the arms 13 and also the function of forming the multiple arms 13 into a single rigid body.

[0019] Of the arms 13 arranged radially in a plan view, the connecting member 30 attached to the arm 13a arranged near the center is also fixed to a reinforcing member 31. The reinforcing member 31 is a strong steel member with one end fixed to the connecting element 4 at the bottom of the vehicle abutment means 2, and is designed to generate strong resistance to compression and tension acting in the longitudinal direction like a diagonal brace. The reinforcing members 31 are provided on the left and right side surfaces of the central arm 13a.

[0020] The arms 13 are connected to each other by connecting members 30, but are also connected to each other at connecting portions 12 that are integral with the vehicle abutment means 2, and are further connected to reinforcing members 31 that are fixed to connecting elements 4 that are part of the vehicle abutment means 2. With this structure, the vehicle underside penetration means 10 made up of the arms 13 is connected to the vehicle abutment means 2 to form a strong structure.

[0021] [Comparative experiment] A comparative experiment was conducted using a model to examine the braking capabilities of the vehicle stopping device 1 of the present invention, in which the arms 3 are arranged in a fan shape, and the conventional (λ-type) vehicle stopping device 100, in which the arms 3 are arranged in parallel rather than fan-shaped. The contents, results, and considerations of the experiment will be explained below. The collision experiment was carried out using the vehicle model 110 shown in Fig. 4 and the collision experiment device shown in Fig. 5. Fig. 4(a) shows a side view of the vehicle model, Fig. 4(b) shows a front view of the vehicle model, Fig. 5(a) shows a side view of the collision experiment device, and Fig. 5(b) shows a plan view of the collision experiment device.

[0022] [Experimental equipment] The vehicle model 110 is formed to the dimensions shown in the figure, and includes tires 111, weights 112, a body frame 113, bearings 114 for guiding straight lines, and the like. The collision test device 120 consists of an air tank 122 connected to an air compressor 121, an air cylinder 123 for pushing out the vehicle model, side guides 124 for improving the straightness of the vehicle model 110 when it is launched, a blackboard (total length 2700 mm, total width 1200 mm) 125 serving as the test surface, a high-speed camera (Photron FASTCAM Mini WX100, Phantom Miro-ex4) 126 for filming the braking behavior during the experiment, and lighting 127. The speed of the vehicle model 110 was set by adjusting the pressure of the air flowing into the air cylinder 123. Two high-speed cameras 126 were installed in the direction of travel of the vehicle model 110, one at a position 1300 mm from the edge of the test road surface 125 and 1860 mm above, and the other at a position 2610 mm vertically away from the side, to observe the behavior of the vehicle model 110 on both the plane and the side.

[0023] [Conventional vehicle stopping device] As shown in Fig. 3, the conventional vehicle stop device 100 is composed of a mast 102, a friction member 103, and an arm 101. The behavior of a model vehicle 110 when it collides head-on with the vehicle stop device 100 is as shown in Fig. 6. Specifically, when the model vehicle 110 enters the conventional vehicle stop device 100, the front part of the model vehicle 110 comes into contact with the arm (Fig. 6(a)), and the model vehicle 110 slides up on the arm 101 while generating a friction force between it and the arm 101 (Fig. 6(b)). The model vehicle 110 then collides with the mast 102, causing the vehicle stop device 100 to rotate around the friction member 103 at the bottom of the mast 102 as the axis of rotation, and the arm 101 lifts up the front part of the model vehicle 110 from below. Then, the kinetic energy of the vehicle model 110 is absorbed while friction work occurs between the friction member 103 at the bottom of the mast and the road surface, creating a braking effect, and the vehicle stopping device 100 and the vehicle model 110 come to a halt after moving a predetermined distance L.

[0024] Figure 7 shows a schematic example of the braking behavior of the vehicle stopping device 100 when the vehicle model 110 enters at an angle, with Figure 7(a) showing a plan view from above and Figure 7(b) showing a view from the front. When the model train 110 approaches the center of the mast 102 from directly in front (perpendicularly), the front of the model train 110 rides up onto the arm and then stops, as described above. However, when the model train 110 approaches the mast 102 at an angle (FIG. 7(a)), the model train 110 tilts depending on the angle of approach and rides up onto the arm 101a at the end (FIG. 7(b)). Furthermore, when the angle of approach is too large, the model train 110 collides with the side of the arm 101a, which can result in insufficient braking performance.

[0025] [Various parameters during the experiment] In this experiment, in order to verify the possibility of a conventional vehicle stopping device 100 responding to an oblique approach, and to examine a new structure in which the arms are arranged in a fan shape, a model collision experiment was conducted with the approach angle of a vehicle model 110 as a parameter to evaluate braking performance. In designing and manufacturing the vehicle stopping device model and vehicle model used in the collision experiment, the law of similarity was taken into consideration, and each model was manufactured at 1 / 10 the dimensions of the original. When conducting the model collision experiment, if the dimensions are reduced to 1 / 10, the mass becomes 1 / 100 and the speed becomes 1 / √10.

[0026] [Experimental model] The conventional vehicle stopping device 100 shown in Figure 3 has a total length of 1075 mm, a total width of 796 mm, a total height of 1015 mm, and a mass of 27.8 kg. The arm 101 has a bent shape, but it has been found that even if it is extended straight, it does not affect braking performance. The conventional vehicle stopping device model (conventional model) 200 used in the experiment was manufactured with a straight arm 201 at 1 / 10 the size of the actual device, as shown in Figure 8. Figure 8(a) shows a side view of the conventional model 200. The conventional model 200 has three arms that are parallel to each other and arranged at right angles to the mast 202. The weight of the conventional model 200 is 0.204 kg. The dimensions are shown in the figure. FIG. 8(b) shows a plan view from above of a vehicle stopping device model (new model) 300 with a new structure in which the arms are arranged in a fan shape.

[0027] The main components such as the mast 202 and arm 201 are made of aluminum alloy (A5052) which is used in the actual vehicle stopping device 100, and the connecting parts and shafts are made of stainless steel (SUS304) strips, which are fastened and fixed with M4 bolts and nuts. For the friction member attached to the bottom of conventional model 200, black butyl rubber was used, with a dynamic friction coefficient (0.93-0.95) close to that of the experimental road surface 125, based on the dynamic friction coefficient (0.85-0.98) between the friction member attached to vehicle stopping device 100 and the actual road surface (asphalt). The friction members were attached to a total of six locations: the lower end of arm 201 and the bottom of mast 202. The friction coefficient was calculated by measuring the normal force (weight of the installed object) and friction force (measured by the load meter) by separately setting up a brake model equipped with friction members and black butyl rubber on the road surface and pushing it in the direction of travel with a load meter.

[0028] 9A and 9B are explanatory diagrams of a new model 300 in which arms are arranged in a fan shape, modeling the vehicle stopping device 1 according to this embodiment for experimental purposes, with Fig. 9A showing a side view of the new model 300 and Fig. 9B showing a plan view seen from above. There are seven arms 301, which are arranged in a fan shape at 15° intervals using arc plates 302 with central arm 301a as the base. In order to compare braking performance with the conventional model 200, the design and improvements were made to make the mass and center of gravity height similar. Although the number of arms 301 was increased to seven, the strength increased, but the weight also increased. Therefore, aluminum alloy (A5052) was used for the connecting parts and shafts, resulting in a weight of 0.2 kg.

[0029] Additionally, the mounting height of the arm 301 and mast 303 was made 10 mm lower than that of the reference model to make the center of gravity height approximately the same. This makes the arm angle (ArmAngle) relative to the road surface gentler, from 30° to 24°, but it is thought that this will make it easier for the model vehicle S to slide up the arm 301 and achieve braking operation similar to that of the vehicle stopping device 100 shown in Figure 6. As with the existing model, black butyl rubber was attached as friction members to a total of 10 locations: the lower end of each arm 301 and the bottom of the mast 303. Table 1 shows the manufactured vehicle stopping device 100, the connecting height of the arms and mast of the fan-shaped model, and the location of the center of gravity.

[0030] [Table 1]

[0031] [Model train] The model vehicle 110 was designed based on the specifications of a typical passenger car (for example, a Toyota Mark X, with a total length of 4770 mm, a total width of 1795 mm, a total height of 1435 mm, and a mass of 1520 kg). As with the vehicle stopping device model, the model vehicle 110 was created based on 1 / 10 dimensions equivalent to a standard passenger car, with the law of similarity taken into consideration. The dimensions and center of gravity position 115 are as shown in Figure 4.

[0032] In this experiment, in order to clarify the difference in the effect of the arm arrangement on the braking characteristics, a simple structure with front-to-back and left-to-right symmetry was used, in which tires 111 were attached to a rectangular plate body frame 113 using bearings, with the aim of eliminating three-dimensional movement of the body. The overall length and wheelbase of the model vehicle 110 were set to 397 mm and 200 mm, respectively, in this experiment, since there is a difference in width between standard passenger cars and these will be items that can be changed on the model vehicle 110 side in future research.

[0033] Carbon steel (S50C) was used for the body and weight adjustment weights. L-shaped members 116 made of aluminum alloy (A5052) were attached to the underside of the front and rear sections of the model vehicle 110, which come into contact with the arm during a collision. The coefficient of dynamic friction between the arm and L-shaped member 116 was 0.27, measured using the method described above. Stainless steel (SUS303) was used for the axle and axle bearing retainer. The mass of the model vehicle 110 was 15.06 kg. Bearings 114 were attached to the four corners of the front and rear of the model vehicle 110, and by running within a guide during launch, straight-line travel was improved.

[0034] [Experimental conditions] In this experiment, the approach speed of the model vehicle 110 was set to three conditions of 1.5 m / s, 2.0 m / s, and 2.5 m / s (equivalent to a real vehicle, approximately 17 km / h, 23 km / h, and 28 km / h), and the model vehicle was launched using an air cylinder. The initial setup of the brake model was such that the tip of the arm 201 of the conventional model 200 and the tip of the arm 301 (301a) of the new model 300 were positioned 850 mm from the edge of the test road surface (blackboard) 125, taking into consideration the range where video recording was possible. Also, assuming that the model train 110 approaches at an angle, as shown in Figure 10, the approach angle of the model train 110 was set to four angles: 0°, 10°, 20°, and 30° with the center C of the mast as the reference. Five collision tests were conducted at each approach speed for each of the conventional model 200 and the new model 300 (hereinafter collectively referred to as "brake model"). The braking distance L was defined as the distance from the initial position of the brake model to the position where the brake model and model train 110 came to a halt. The distance L was measured using a steel ruler, and the distance components in the X and Y directions, Lx and Ly, were obtained.

[0035] The entire behavior of the model train 110, from entering the brake model, coming into contact with it, braking, and stopping, was filmed at 1000 fps using a high-speed camera from above and from the side in the direction of travel of the model train 110. After the collision test, the bolts and other components used in the brake model were checked for looseness and adjustments were made before the next test was conducted. Before and after the collision test, the brake model was pushed in the braking direction with a load meter to measure the friction force of the friction members attached to the bottom of the arm and mast, and it was confirmed that the value of the friction coefficient did not change due to braking.

[0036] [Braking behavior of conventional model] Fig. 11 shows photographs of the braking behavior of the conventional model 200 when the model train 110 approaches at an angle, and illustrates the braking behavior of the conventional model 200 and the brake model at an approach angle of 10° and an approach speed of 2.5 m / s. The left side of the photograph is a side view taken from the side, and the right side is a plan view taken from above. Fig. 11(a) shows the state when the model train 110 approaches the brake model and comes into contact with the arm (t=0), Fig. 11(b) shows the state when the front part of the model train 110 slides up the arm and collides with the mast (t=194 ms), and Fig. 11(c) shows the state when the front part of the model train 110 rotates around the Y axis, lifting the bottom of the mast as the center, and then the model train 110 and the brake model apply the brake together to stop the model train 110 (t=595 ms).

[0037] FIG. 12 shows an enlarged plan view of the braking behavior of the conventional model 200 in a horizontal plane. FIG. 12(a) shows the state at the time (t=0 ms) when the model train 110 comes into contact with the arm. The circle indicates the position of the arm at the right end where the model train 110 comes into contact. FIG. 12(b) shows the state in which the conventional model 200 rotates counterclockwise around the Z axis by the same angle as the approach angle of the model train 110, and faces forward relative to the model train 110. Thereafter, the conventional model 200 moves forward in unison with the model train 110 until it stops. This rotational behavior of the conventional model 200 was similarly confirmed at approach speeds of 1.5 m / s and 2.0 m / s.

[0038] 13 shows the case where the model train 110 collides with the conventional model 200 at an approach speed of 2.5 m / s and an approach angle of 30°. This behavior is similar to the case where the model train 110 collides with the conventional model 200 at an approach speed of 2.5 m / s and an approach angle of 20°, and the model train 110 cannot be stopped. Explaining the behavior in detail, Fig. 13(a) shows the state at the time when the model train 110 comes into contact with the arm (t = 0 ms). Fig. 13(b) shows the state at the time when the conventional model 200 starts to rotate counterclockwise around the Z axis (t = 182 ms). Fig. 13(c) shows the state at the time when the conventional model 200 continues to rotate counterclockwise around the Z axis and releases contact with the model train 110 (t = 318 ms). Fig. 13(d) shows the state at the time when the model train 110 avoids contact with the conventional model 200 and continues traveling straight ahead (t = 516 ms). When the approach speed was 1.5 m / s and 2.0 m / s, the braking behavior was similar to that when the approach angle was 10° as described above, and the model train 110 was able to be braked and stopped.

[0039] [Braking behavior of new model] Figure 14 shows the braking behavior of the new model 300 when the approach angle is 10° and the approach speed is 2.5 m / s as an example. The braking behavior of the new model 300 under these conditions was similar to that shown in Figures 11(a) to 11(c). The detailed braking behavior of the new model 300 as seen from above in a plan view is as shown in Figure 15, where the front part of the model train 110 slides up the arm and hits the right end of the mast (Figure 15(a)), after which the new model 300 rotates counterclockwise in a horizontal plane (Figure 15(b)), faces the front of the model train 110 (Figure 15(c)), then becomes one with the model train 110, moves straight along the approach direction of the model train 110, and stops. This behavior was the same when the approach speed was 1.5 m / s and 2.0 m / s.

[0040] When the model vehicle 110 had an approach speed of 2.5 m / s and an approach angle of 20° and 30°, the conventional model 200 was unable to brake or stop the model vehicle 110, but as shown in Figure 16 (as an example, an approach angle of 30°), the new model 300 was able to stop the model vehicle 110 without any problems. Figure 16(a) shows the time when the model train 110 comes into contact with the new model 300 (t=0 ms), Figure 16(b) shows the state when the model train 110 is being braked by the new model 300 (t=260 ms), and Figure 16(c) shows the time when the model train 110 and the new model 300 come to a stop (t=802 ms). As shown in Figure 16 above, the behavior of the new model 300, both in side view and plan view, exhibited braking behavior similar to that at the aforementioned approach angle of 10°. As can be seen from this result, by arranging the arms in a fan shape, the angle that can be accommodated for the model train 110 approaching at an angle is wider than that of the conventional model 200, and functionality is improved.

[0041] [Braking distance] In order to verify the effect of the arm arrangement on the braking distance for different approach angles α, the experimental braking distances D obtained in collision tests of the conventional model 200 and the new model 300 are compared. 17(a) shows the average value and measurement range of the braking distance D of the conventional model 200, and FIG. 17(b) shows the average value and measurement range of the braking distance D of the new model 300. In the case of the conventional model 200, when the approach angle α of the model train 110 was 10°, with 0° as the reference, the braking distance was approximately the same at all approach speeds, but as the approach angle increased to 20° and 30°, the braking distance tended to become longer. Furthermore, at a speed of 2.5 m / s, the model train 110 could not be stopped when the approach angle α was 20° or 30°. From these results, it became clear that the conventional model 200, which has three arms arranged in parallel, has a limit to the approach angle of about 20°, and is unable to adequately brake the model train 110 approaching at an angle. These results can be analogously applied to the conventional vehicle stopping device 100.

[0042] On the other hand, the new model 300, in which the arms are arranged in a fan shape, is able to brake even when the approach angle is large, and it is clear that it has the same braking performance as the conventional model 200 in a head-on collision (approach angle α = 0°). This confirms that the structure in which the arms are arranged in a fan shape improves the braking function for the model train 110 approaching at an angle. This result can be analogously applied to the vehicle stopping device 1 of this embodiment.

[0043] [Discussion: Braking behavior] When the model vehicle 110 approaches the conventional model 200 at an angle, it is possible to brake the model vehicle 110 if the angle of approach is small and the model vehicle 110 can climb onto the arm, but it has been confirmed that it is difficult to deal with the model vehicle 110 approaching at an angle if the angle of approach is large and the model vehicle 110 collides with the side of the arm. In contrast, in the case of the fan-shaped new model 300, the arms are arranged radially from the mast, which allows the model train 110 approaching at an angle to climb onto the arms, enabling braking at an approach angle of 30°. In this case, after the model train 110 climbs onto the arms and collides with the mast, the new model 300 rotates to face the model train 110 head-on, and they brake together.

[0044] This braking behavior was confirmed using motion analysis software (Recurdyn V9R5). The analytical model was created based on the dimensions and shape of the fan-shaped new model 300 and the model train 110. The friction coefficients of the contact points were based on actual measurements, with 0.27 used between the arm and the underside of the model train 110 and 0.94 used between the road surface and the bottom end of the mast. Figure 18 shows the analysis results, which reproduce the behavior confirmed in the collision experiment. It was found that the force generated when the front of the model train 110 collided with the right end of the mast caused the new model 300 to rotate, and as it faced forward, it became one with the model train 110, braking in accordance with the approach angle of the model train 110.

[0045] In Figure 17, the braking distances D obtained in both crash tests are compared. Next, we will consider the effect of the approach angle α on the braking direction. Figure 19(a) shows the X-direction distance (Dx) and Y-direction distance (Dy) of the braking distance D for the conventional model 200, and Figure 19(b) shows the new model 300. The X-direction distance (Dx) is the distance component in the direction of travel of the vehicle before braking, and the Y-direction distance (Dy) is the distance component in a horizontal plane perpendicular to the direction of travel of the vehicle before braking. The open triangles, squares, and circles in Figure 19 are plots of the X-direction distance (Dx) corresponding to each intrusion speed of the model vehicle 110, and the filled triangles, squares, and circles are plots of the Y-direction distance (Dy) corresponding to each intrusion speed of the model vehicle 110.

[0046] In the case of the conventional model 200, the X-direction distance (Dx) showed a similar trend to the braking distance D. When the approach angle was large, the model train 110 could not be braked, resulting in an inability to stop and an extended braking distance. This is thought to be due to the model train 110 not climbing onto the arm, or, even if it did climb onto the arm, the model train 110 would tilt. As for the Y-direction distance (Dy), the braking distance became longer as the approach angle increased.

[0047] With the new model 300, as the approach angle increased, the X-direction distance (Dx) decreased and the Y-direction distance (Dy) increased. As the new model 300 rotates to face the front of the model vehicle 110 in response to the model vehicle 110 approaching at an angle, braking the model vehicle 110's progress along the approach direction, so the braking distance D was the same regardless of the approach angle. For this reason, it is believed that the X-direction component and Y-direction component changed as the approach angle increased. By arranging the arms in a fan shape, response to the model vehicle 110 approaching at an angle was greatly improved.

[0048] [Comparison with theoretical braking distance] A formula for deriving the braking distance through theoretical calculation was constructed, taking into consideration the braking behavior when the rear wheels are in the ground contact state, as with the conventional vehicle stopping device 100 shown in Figure 6. The period from when the model vehicle 110 comes into contact with the arm of the vehicle stopping device, to when it slides up the arm with friction and hits the mast (Figure 6(a) to Figure 6(b)), is the first stage, and the period from when it hits the mast until the model vehicle 110 and the brake body move together and come to a stop (Figure 6(c)) is the second stage, and a theoretical formula was devised using the laws of conservation of energy and conservation of momentum. When braking a vehicle S entering at an angle, as mentioned above, a rotational movement of the vehicle stopping device 1 occurs after the vehicle S collides with the mast, so it is necessary to derive the speed at which the vehicle starts to move together, taking into account the frictional work that occurs at this time. Here, only the formulas for the movement start speed V1 after integration and the theoretical braking distance l are shown. The speed V"0 at which the vehicle S and the conventional vehicle stopping device 1 start moving immediately after the vehicle S collides with the mast is expressed by Equation 1.

number

[0049] where m1: vehicle weight [kg], m2: weight of the conventional vehicle stopping device 100 [kg], V0: approach speed of vehicle S [m / s], μ1: coefficient of dynamic friction between vehicle S and the arm, μ2: coefficient of dynamic friction between the friction member and the road surface, δ=(hR) / sinθ: sliding distance on the arm [m], h: height from the road surface to the mounting position of the mast and arm [m], R: vertical distance from the bottom of the model vehicle 110 to the road surface [m], θ: arm angle [°], L: horizontal distance from the front part of the model vehicle 110 to the center of the rear wheel axle [m], a: horizontal distance from the center of gravity of the model vehicle to the front part of the model vehicle [m], b: horizontal distance from the center of gravity of the model vehicle 110 to the center of the rear wheel axle [m], g: gravitational acceleration [m / s 2 ].

[0050] As shown in Figure 20, after the model vehicle 110 collides with the end of the mast, it is assumed that the conventional vehicle stopping device 100 rotates around the center of the mast by an angle equal to the approach angle of the model vehicle 110. At this time, friction work W1 is generated between the friction member and the road surface. Here, P is the overall width of the mast [m], r is the distance [m] from the center of the mast width to an arbitrary position in the width direction, dr is the infinitesimal distance [m] from the center of the mast width at the arbitrary position, and α is the vehicle approach angle [rad]. At this time, the friction force acting on the infinitesimal section dr between the friction member and the road surface is μ2((b / L)m1+m2)g·dr / p [N]. Since the mast rotates and moves rα [m] at that position, the friction work dW1 in the infinitesimal section can be expressed by Equation 2.

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[0051] Since the amount of rotational movement differs depending on the position from the center of the mast, the friction work W1 of the entire mast is expressed by equation 3.

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[0052] After the brake body rotates, the speed V1 at which the vehicle S and the conventional vehicle stopping device 100 become one and start moving straight ahead can be expressed as follows by substituting Equations 1 and 3 according to the law of conservation of energy, using the frictional work W1 due to the rotation of the mast and the speed V"0 at which the model vehicle 110 and the conventional vehicle stopping device 100 start moving immediately after the model vehicle 110 collides with the mast:

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[0053] The theoretical braking distance l can be calculated by substituting the motion start speed V1 (Equation 4) after integration into the equation derived in Non-Patent Document 1, "Study on braking mechanism and braking performance evaluation of intrusion vehicle stopping device (lambda-type forced braking body for automobiles)" and rearranging it.

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[0054] The theoretical braking distance was calculated by substituting the dimensions, weight, etc. of the model vehicle 110 (Fig. 4) and the brake model (Fig. 3, Table 1) into Equation 5. As in the motion analysis, the dynamic friction coefficient μ1 between the front part of the model vehicle 110 and the arm was set to 0.27, and the dynamic friction coefficient μ2 between the friction member and the road surface was set to 0.94. The mounting heights (arm angles) of the arm and mast are different in both the conventional model 200 and the new model 300 brake body models, but the difference in the distance δ that slides up the arm due to differences in arm angle is only small (7 mm), and the effect on the theoretical value is very small. Therefore, only the theoretical braking distance when the model vehicle 110 is at an approach angle of 30° with a fan-shaped brake body is shown in Figure 21.

[0055] Figure 21 shows the average braking distances for the vehicle stopping device 100 (white circles) and the fan-shaped model (black circles) at various approach speeds when the model vehicle approaches at an approach angle of 30°, for comparison with the theoretical braking distance. For reference, a simplified theoretical braking distance (see Appendix A) is also shown. Comparing the experimental braking distances with the theoretical braking distances, the fan-shaped model generally agreed at all approach speeds. The conventional model 200's experimental braking distance was longer than the theoretical braking distance due to insufficient arm ride-up. As with the existing brake reported in Non-Patent Document 1, it is possible to estimate the braking distance using a theoretical formula for a brake with fan-shaped arms. While a simplified formula is sufficient for estimation, it is considered better to consider the energy dissipation mechanism, even if it is small, when verifying and evaluating braking behavior. Changing the arm arrangement to a fan shape can adequately accommodate braking for vehicles approaching at an angle and is therefore a more optimal structure than the existing shape. Although these results were obtained from the collision of the model train 110 used in this report, we believe they can be used to improve actual braking systems, consider new models, and as guidelines and countermeasures for problem solving. In the future, we will conduct evaluations through both collision tests and motion analysis to optimize the structure of dimensions and shape, consider new mechanisms, and stabilize braking behavior, all of which will lead to improved braking performance using lambda-shaped braking systems, such as improving friction at contact points and implementing impact absorption measures. In addition, because braking behavior is also affected by the model train being collided with, we will change the dimensions, the position and height of the center of gravity, and components (changing the shape of the front (collision) part of model train S and absorbing energy through plastic deformation), and conduct evaluations and verifications through collision tests that also take offset collisions into account.

[0056] [Conclusion] The purpose of this experiment was to study the optimal structure of a vehicle stopping device in order to improve the braking performance of the conventional vehicle stopping device 100, and to verify its effectiveness through performance evaluation. A new structure was studied in which the arm arrangement of the conventional vehicle stopping device was changed to a fan shape so that it could handle braking for vehicles approaching at an angle, and an evaluation was made of the effect of the fan shape arrangement on braking performance. Model collision experiments, motion analysis, and theoretical calculations were carried out, and braking performance was evaluated by comparing braking distances. The conclusions are presented below. (1) When the arms are arranged parallel to each other, the arms may become unstable as the approach angle increases for a model vehicle approaching at an angle, and the model vehicle may not be able to adequately respond to braking. (2) The fan-shaped arrangement of the arms is an effective structure because it allows a model vehicle approaching at an angle to ride onto the arms regardless of the angle of approach, making it possible to brake and stop the vehicle.

[0057] [Appendix A] In deriving the theoretical braking distance for vehicle braking using a lambda-shaped brake, we derive a simple estimation formula that takes into account the weight ratio of the two colliding objects, the contact length at each contact surface, and differences in the kinetic friction coefficient. The theoretical braking distance (Equation 5) presented in this paper takes into account four types of energy dissipation: (a) friction between the front of the vehicle and the arm, (b) inelastic collision between the vehicle and the mast, (c) friction with the road surface due to the rotation of the brake, and (d) friction with the road surface when the vehicle and brake are braking together. In (a), the kinetic friction coefficient μ1 between the underside of the front of the vehicle and the arm is smaller than μ2 between the road surface and the friction member at the bottom of the mast (μ1 = 0.27, μ2 = 0.94 in this model collision experiment), and the contact length on the arm is also smaller than that on the road surface (for an arm length of approximately 0.1 m, the braking distance is approximately 1.0 m at an approach speed of 2.5 m / s). Therefore, the energy dissipation due to friction between the vehicle and the arm is small compared to the dissipation due to friction between the brake and the road surface after they have united (approximately 3% at an approach speed of 2.5 m / s). Regarding mechanism (c), the energy dissipation is also small because the amount of mast rotation is small. Furthermore, because the vehicle weight m1 is much larger than the brake weight m2 (m2 / m1 = 0.2 / 15.06 = 0.013), the change in vehicle speed due to collision with the brake is approximately 1.3%, and the energy dissipation due to (b) is also small. Based on these findings, we infer that process (d) is dominant in the collision experiments reported in this report. Ignoring the energy dissipation mechanisms (a) to (c) and the brake weight, we derive a simple estimation formula, using the speed at which the brake and vehicle begin to move together as the vehicle approach speed.

[0058] When the brake body and vehicle become one, the reaction force (normal force) Ws generated on the contact surface of the friction member at the bottom of the mast due to contact with the front of the vehicle is expressed by the following equation based on the balance of moments around the center of the rear wheel axle of the vehicle.

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[0059] where m1 is the vehicle mass [kg], L is the horizontal distance from the front of the vehicle to the center of the rear wheel axle [m], b is the horizontal distance from the center of gravity of the vehicle to the center of the rear wheel axle [m], and g is the gravitational acceleration [m / s 2 If we assume that the kinetic energy of a vehicle moving at an approach speed of V0 [m / s] is used to perform frictional work on the friction member at the bottom of the mast (coefficient of dynamic friction with the road surface μ2) and that it is stopped, then the braking distance l' (simple estimate) can be expressed by the following equation based on the law of conservation of energy:

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[0060] The present invention can be used as a means for preventing vehicles from entering a construction area when road construction is being carried out. [Explanation of symbols]

[0061] 1 Vehicle stopping device 2 Vehicle contact means 3 Vertical Elements 4 Connecting Elements 5 Contact member 6 Bottom wall 7 side wall 8 Friction means 9 Fixing means 10 Vehicle bottom penetration means 11 Base 12 Joint 13 Arm 14 Friction means 15 Slope section 20 Semicircular Plate 21 Semicircular Plate 30 Connecting member 31 Reinforcement member 100 Vehicle stopping device 101 Arm 102 Mast 103 Friction members 110 Vehicle Model 111 Tires 112 Weight 113 Body frame 114 Bearing 115 Center of gravity position 116 L-shaped member 120 Collision Test Device 121 Air Compressor 122 Air Tank 123 Air Cylinder 124 Side guide 125 Experimental Road Surface 126 High-Speed ​​Camera 127 Lighting 200 conventional model 201 Arm 202 Mast 300 Vehicle Stop Device (New Model) 301 Arm 301a Arm 302 Arc Plate 303 Mast S model train

Claims

1. a vehicle contact means extending upward from the ground contact portion at the lower end; a plurality of vehicle bottom entry means provided with sloped surfaces that are inclined downward toward the vehicle; A vehicle stopping device characterized in that the plurality of vehicle bottom intrusion means are radially arranged with increasing spacing toward the tip.

2. 2. The vehicle stopping device according to claim 1, wherein the plurality of vehicle bottom intrusion means are arranged at equal angles about an imaginary reference point in a plan view and are fixed to one another.

3. 3. The vehicle stopping device according to claim 2, wherein the vehicle contact means is formed by a plurality of steel members arranged in parallel and connected to each other.

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