Construction vehicle

Abstract

To provide a construction vehicle capable of achieving both of safety and work efficiency.SOLUTION: A construction vehicle 1 is equipped with an emergency braking device 10. The emergency braking device 10 has: an obstacle sensor 12; a control device 13 including a determination unit 31 for determining the presence or absence of an obstacle G; a vehicle speed sensor 11 for outputting vehicle speed data to the control device 13; and a braking device 14 for applying an emergency brake to a vehicle when the determination unit 31 determines that the obstacle G is present. The construction vehicle turns off a function of the emergency braking device 10 and notifies an operator of the fact that the function of the emergency braking device is turned off when a vehicle speed is greater than a setting value, turns on the function of the emergency braking device 10 when the vehicle speed is equal to or less than the setting value, and turns on the function of the emergency braking device when it is determined that the vehicle has completely stopped after the function of the emergency braking device 10 is turned off.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] The present invention relates to a construction vehicle equipped with an emergency braking device. [Background technology]

[0002] For example, an obstacle detection device that detects obstacles present near a construction vehicle, such as a compaction roller, is known (see Patent Document 1). The obstacle detection device described in Patent Document 1 has a control device equipped with a determination unit that determines the presence or absence of an obstacle based on data from a sensor, and an emergency braking device that applies emergency brakes to the vehicle after the determination unit detects an obstacle.

[0003] While conventional emergency braking devices are effective in terms of safety, such as collision avoidance, they can also cause false detections, increase the burden on operators, and cause damage to compacted objects due to sudden braking. In other words, it is difficult to achieve both safety and work efficiency.

[0004] For example, in order to improve work efficiency, it is conceivable to apply sudden braking at the very limit of braking avoidance, but there is a risk that defects such as extrusion, peeling, or damage to the object to be compacted may occur due to sudden braking. Furthermore, for example, in order to prevent adverse effects on the object being compacted, it may be possible to apply gentle braking without waiting for the braking avoidance limit to be reached, but this is an unintended movement for the operator, and this could place a heavy burden on the operator.

[0005] Although emergency braking devices can increase safety in this way, they can also be difficult for operators to use and are difficult to utilize. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Japanese Patent Application Publication No. 2019-12394 Summary of the Invention [Problem to be solved by the invention]

[0007] On the other hand, construction vehicle drivers are often dual-task workers who operate vehicles when needed. As a result, operators change frequently and vehicles often start from a stopped state. Also, when vehicles are stopped, they are often grouped together in a small area within the construction site to avoid any deterioration in the quality of the compacted object (such as dents). Operators and workers tend to be relatively alert while driving, but when vehicles start from a stopped state, they tend to be less attentive to their surroundings due to the slow vehicle speed.

[0008] Furthermore, when driving for work, the operator stops and checks for safety around the vehicle before operating the forward / reverse lever to move forward. However, in reality, the operator must not only operate the forward / reverse lever while moving slowly and checking the direction of travel, but also pay attention to the situation of work being done in the surrounding area, which often leads to accidents where the vehicle is caught in the vehicle when starting off.

[0009] Therefore, an object of the present invention is to provide a construction vehicle that can achieve both safety and work efficiency. [Means for solving the problem]

[0010] The present invention is a construction vehicle equipped with an emergency braking device, the emergency braking device comprising: an obstacle sensor that detects obstacles; a control device having a judgment unit that judges the presence or absence of an obstacle based on the obstacle sensor; a vehicle speed sensor that measures vehicle speed and outputs vehicle speed data to the control device; and a braking device that applies emergency brakes to the vehicle when the judgment unit judges that an obstacle is present, wherein when the vehicle speed is greater than a set value, the function of the emergency braking device is turned OFF and an operator is notified that the function of the emergency braking device is OFF; when the vehicle speed is equal to or less than the set value, the function of the emergency braking device is turned ON; and after turning OFF the function of the emergency braking device, when it is judged that the vehicle has come to a complete stop, the function of the emergency braking device is turned ON.

[0011] According to the present invention, when the vehicle speed is higher than a set value, the emergency braking device function is turned off, thereby improving work efficiency. In other words, when the vehicle speed is relatively high, the operator and workers are likely to be attentive, so the emergency braking device is not activated, prioritizing work efficiency. On the other hand, when the vehicle speed is equal to or lower than the set value, the emergency braking device function is turned on, thereby improving safety when the vehicle starts moving. In addition, the notification allows the operator to know that the emergency braking device will not function.

[0012] It is also preferable that the vehicle is provided with a forward / reverse lever that switches the vehicle between forward and reverse and activates the brake in a neutral position, and that the vehicle is determined to have come to a complete stop when the vehicle speed becomes zero for a predetermined period of time, when the forward / reverse lever is in the neutral position for a predetermined period of time, or when a parking button that mechanically stops the vehicle is turned on.

[0013] For example, when a vehicle switches back and forth multiple times, the vehicle speed temporarily drops to zero when the vehicle switches back and forth. Turning the emergency braking device on and off each time this happens would complicate control. According to the present invention, turning the emergency braking device on when the vehicle comes to a complete stop facilitates control. Furthermore, because the emergency braking device is already on when the vehicle starts moving again, safety is enhanced.

[0014] Furthermore, when the vehicle is stopped, it is preferable to determine whether or not there is an obstacle before determining whether or not the vehicle speed is greater than the set value, and if the determination unit determines that there is an obstacle, to turn on the function of the emergency braking device.

[0015] For example, if there is an obstacle near the vehicle while it is stopped, extra caution is required when starting off. In such a case, the present invention can enhance safety by turning on the emergency braking device function.

[0016] It is also preferable to provide an inclination sensor that measures the inclination angle of the vehicle and outputs inclination angle data to the control device, and when the vehicle is stopped, determine whether the stopping position is inclined before determining whether the vehicle speed is greater than the set value, and if it is determined that the stopping position of the vehicle is inclined, determine whether the vehicle speed is greater than the set value.

[0017] When the vehicle is parked on an incline, the vehicle speed increases and the braking distance increases after it starts moving, so safety may not be guaranteed even if the emergency braking device is turned on. According to the present invention, the function of the emergency braking device can be quickly turned off.

[0018] It is also preferable that the set value be set smaller as the tilt angle of the vehicle increases. [Effects of the Invention]

[0019] According to the construction vehicle of the present invention, it is possible to achieve both safety and work efficiency. [Brief explanation of the drawings]

[0020] [Figure 1] 1 is a plan view of a construction vehicle according to a first embodiment of the present invention. FIG. [Figure 2] FIG. 1 is a side view of a construction vehicle according to a first embodiment. [Figure 3] FIG. 1 is a block diagram of a construction vehicle according to a first embodiment. [Figure 4] FIG. 2 is a schematic hydraulic circuit diagram of a traveling system including a braking device of the construction vehicle according to the first embodiment. [Figure 5] 4 is a graph showing a braking start distance of the construction vehicle according to the first embodiment. [Figure 6] 10 is a table (high speed range) summarizing the state of the construction vehicle according to the first embodiment. [Figure 7] 10 is a table (low gear) summarizing the state of the construction vehicle according to the first embodiment. [Figure 8] 4 is an operation flow of the emergency brake device for the construction vehicle according to the first embodiment. [Figure 9] 10 is an operational flow of an emergency brake device for a construction vehicle according to a second embodiment of the present invention. [Figure 10] 10 is an operational flow of an emergency brake device for a construction vehicle according to a third embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0021] First Embodiment A first embodiment (present embodiment) for carrying out the present invention will be described below. However, the present invention is not limited to the following content and the content shown in the drawings, and can be implemented by any modifications within the scope that does not impair the effects of the present invention. In the following description, the same components in different embodiments will be given the same reference numerals, and duplicated explanations will be omitted. Furthermore, the same names will be used for components with the same functions, and duplicated explanations will be omitted.

[0022] 1 and 2, a construction vehicle 1 of the present invention comprises a vehicle body 2, tires 3, an emergency braking device 10, a working device 20, and a transmission (not shown). The construction vehicle 1 is exemplified as a compaction roller that compacts an object to be compacted while traveling at a low speed, but it may be other rollers such as a road roller or a vibratory roller, or may be a road cutter or a road stabilizer. A plurality of tires 3 are installed at the front and rear of the vehicle body 2, and they compact the object to be compacted by rolling.

[0023] 3, the emergency braking device 10 includes a vehicle speed sensor 11, an obstacle sensor 12, a control device 13, a braking device 14, and an alarm device 15. The vehicle speed sensor 11 measures the vehicle speed of the construction vehicle 1 and transmits the vehicle speed data to the control device 13. The vehicle speed sensor 11 may be a proximity sensor such as a rotary encoder that detects the number of rotations of the tires 3.

[0024] The obstacle sensor 12 is, for example, a TOF (Time Of Flight) distance image sensor (3D distance sensor) that measures distance from the time difference between projected light and reflected light. The obstacle sensor 12 includes a light-emitting unit that emits projected light such as infrared light and a light-receiving unit that receives the reflected light when the projected light hits an object. The distance to the object is measured by measuring the time between when the light-emitting unit transmits the infrared light and when the light-receiving unit receives the reflected light. The projection angle from the obstacle sensor 12 is, for example, a horizontal angle (θ2 shown in FIG. 1) of 95° and a vertical angle (θ1 shown in FIG. 2) of 32°, and the projection cross section has a horizontally elongated rectangular shape. The image resolution is, for example, 64 pixels horizontally and 16 pixels vertically, for a total of 1024 pixels. The obstacle sensor 12 is attached to the rear of the vehicle body 2 in the center in the vehicle width direction so that the projected light is projected diagonally downward in the reverse direction.

[0025] Regarding the detection range of obstacle G, if the projection range of the projected light is set as the detection range as is, in other words, if the dimension L1 in the vehicle width direction is set wider than the vehicle width dimension of the construction vehicle 1, the presence of obstacle G will be recognized even though there is no risk of collision, causing the vehicle to stop unnecessarily. For this reason, it is preferable to set the dimension L1 of the detection range 4 in the vehicle width direction (shown by diagonal lines in FIG. 1) to be approximately the same as the vehicle width dimension of the construction vehicle 1.

[0026] Because the obstacle sensor 12 can measure the distance to the obstacle G, a determination unit 31 (see FIG. 3) of the control device 13 can determine whether or not the obstacle G is present within the detection range 4, which is set to the vehicle width dimension, based on the measurement data for each pixel, specifically the distance between the obstacle sensor 12 and the obstacle G in the vehicle width direction. By using the obstacle sensor 12 in this way, the dimension L1 of the detection range 4 can be ensured to be constant across the vehicle's fore-and-aft direction. That is, the detection range 4 can be easily set to a substantially rectangular range with one side having the dimension L1 in a plan view, as shown in FIG. 1. The dimension L2 of the detection range 4 in the vehicle's fore-and-aft direction is set appropriately depending on the vehicle's usual speed, and in this embodiment, it is set to, for example, about 3 meters.

[0027] Furthermore, because the light projected by the obstacle sensor 12 is projected diagonally downward in the reverse direction, the lateral angle θ2 of the projected light when viewed from above (see FIG. 1) is greater than 95°. Therefore, the distance L3 in the fore-and-aft direction of the vehicle can be kept small for the non-detection ranges 5, 5 formed between the rear ends of the construction vehicle 1 and the detection range 4. In other words, the non-detection blind spots formed on both sides of the rear of the vehicle can be reduced.

[0028] The emergency braking device 10 includes a braking device 14 (see FIG. 3) that applies the brakes to the vehicle when it is determined that an obstacle G is present within the detection range 4. The braking device 14 may have any configuration as long as it can stop the vehicle, but an example will be described below.

[0029] In Figure 4, a travel pump P driven by a prime mover (not shown) and a travel motor M that rotates tires 3 (Figure 1) are connected in series to form a closed hydraulic circuit U1. The travel pump P is a swash plate pump. Oil lines T1 and T2 for operating the swash plate are connected to the travel pump P. A two-position, three-port solenoid valve V1 is installed between the oil lines T1 and T2 in parallel with the travel pump P.

[0030] When the prime mover is running, solenoid valve V1 is in the right position in Figure 4, disconnecting oil passage T1 from oil passage T2. Therefore, when the forward / reverse lever around the driver's seat is tilted toward the forward position while the prime mover is running, swash plate hydraulic oil flows from oil passage T1 to oil passage T2, tilting the swash plate to one side. This causes pressure oil to flow in one direction in closed circuit U1, rotating the travel motor M in one direction and moving the vehicle forward. When the forward / reverse lever is tilted toward the reverse position, swash plate hydraulic oil flows from oil passage T2 to oil passage T1, tilting the swash plate to the other side. This causes pressure oil to flow in the other direction in closed circuit UI, rotating the travel motor M in the other direction and moving the vehicle backward.

[0031] When the prime mover is not running, solenoid valve V1 is in the left position as shown in Figure 4, and oil lines T1 and T2 are in communication. A hydraulic closed circuit U2 is formed between solenoid valve V1 and travel pump P, and no pressure difference occurs between oil lines T1 and T2, so the swash plate is in the neutral position. This causes the HST (Hydro Static Transmission) brake to operate in closed circuit U1.

[0032] The braking device 14 of this embodiment utilizes this electromagnetic valve V1, and when an obstacle is detected while the vehicle is reversing, the control device 13 outputs a brake signal to switch the electromagnetic valve V1 from the right position to the left position. As a result, even if the prime mover is engaged and the forward / reverse lever remains tilted toward the reverse position, the swash plate is positioned in the neutral position, the HST brake is applied in the closed circuit U1, and the travel motor M is stopped. Note that a electromagnetic valve V2 is interposed between the charge pump P1 built into the travel pump P and the negative brake M1 built into the travel motor M to activate the negative brake (parking brake) M1 during parking.

[0033] The timing from when the control device 13 determines that an obstacle G is present until when it outputs a brake signal, i.e., the braking start timing of the braking device 14, is preferably changed according to the vehicle speed. As shown in Fig. 5, the control device 13 compares a brake start distance S, which is preset according to the vehicle speed, with the distance to an obstacle G present in the detection range 4 measured by the obstacle sensor 12, and outputs a brake signal to the electromagnetic valve V1 when the distance to the obstacle G becomes equal to or less than the brake start distance S. The brake start distance S is set to, for example, a distance that is slightly larger than the vehicle's actually measured limit braking distance T. A memory unit 32 of the control device 13 stores data files of these brake timings, as well as a data file of the ON / OFF timing of the emergency braking device 10, which will be described later.

[0034] As shown in FIG. 3, the notification device 15 is a device that notifies the operator by sound or display. The notification device 15 may notify by either sound or display, or may use both. For example, after determining that an obstacle G is present, the notification device 15 notifies by only sound when there is sufficient distance to the obstacle G. Alternatively, the notification device 15 may display on a display device (monitor, display, etc.) provided on the vehicle body 2 that an obstacle G has been detected to call attention to the situation. In addition, in this embodiment, as will be described later, the notification device 15 notifies by sound or display that the function of the emergency braking device 10 is OFF. Alternatively, the notification device 15 may be configured to notify by sound or display that the function of the emergency braking device 10 is ON.

[0035] As shown in Figures 1 and 2, the work device 20 is a device that performs a secondary task that supports the main task of the construction vehicle. In the case of a compaction roller as in this embodiment, the work device 20 is, for example, a liquid spraying device that sprays water or liquid onto the tire 3. Spraying water or liquid onto the tire 3 can prevent foreign matter from adhering to the tire 3. The work device 20 varies depending on the type of construction vehicle, but may be, for example, a cutting device that cuts an object, an agitating device that agitates an object, a vibrating device that vibrates, a transport device such as a belt conveyor, etc.

[0036] The parking brake is a device that can maintain the vehicle in a stopped state regardless of whether the prime mover is on or off. The operator can activate the parking brake by turning the parking button on and off on the dashboard. As shown in Fig. 4, the parking brake can be the negative brake M1 in the HST circuit or a mechanical parking brake.

[0037] The transmission (not shown) is a device that can change the driving mode of the vehicle. The transmission has two driving modes, for example, a high speed range of 0 to 10 km / h and a low speed range of 0 to 5 km / h. The high speed range allows the vehicle to travel at high speed and is used, for example, for transporting the vehicle. The low speed range allows the vehicle to travel at low speed and is used for compaction work. The driving mode can be changed as needed, for example, by the operator switching a speed change switch provided on the dashboard. The transmission may have three or more driving modes, and the threshold values ​​may also be set as needed.

[0038] <Operation of the emergency braking device 10: High speed> Fig. 6 is a table showing a series of states of the construction vehicle 1 in the high-speed range. Fig. 6 shows the operating status of each device when the construction vehicle starts from a stopped state, travels for out-of-service, and stops when it arrives at its destination. As shown in Fig. 6, in the high-speed range, the vehicle goes from a stopped state at No. 1-1 and 1-2 to a running state at No. 2-1 to 2-4, and then stops at No. 3-1 to 3-3, completing work.

[0039] The forward / reverse lever in FIG. 6 is a lever that switches the vehicle between forward and reverse and also activates a brake (e.g., an HST brake) when in the neutral position. The speed can be varied by the tilt angle of the forward / reverse lever. For example, in the high-speed range, tilting the forward / reverse lever to the fullest extent will result in 10 km / h. Also, in the high-speed range, tilting the forward / reverse lever halfway will result in approximately 5 km / h, and in the low-speed range, tilting the forward / reverse lever halfway will result in approximately 2.5 km / h. In FIGS. 6 and 7, "F" in the forward / reverse lever column indicates when the lever is in the forward position, "R" indicates when the lever is in the rearward position, and "N" indicates when the lever is in the neutral position.

[0040] As shown in the rightmost column of Figure 6, the function of the emergency braking device 10 remains ON from the time the prime mover is turned ON in the high speed range until the vehicle stops traveling and the prime mover is turned OFF. In other words, in the high speed range, when the prime mover is turned ON, the emergency braking device 10 is automatically turned ON, and remains ON even when the vehicle stops. When the vehicle stops traveling completely at No. 3-3 and the prime mover is turned OFF, the emergency braking device 10 is also turned OFF accordingly.

[0041] <Operation of the emergency braking device 10: Low gear> On the other hand, Figure 7 is a table showing a series of states of the construction vehicle 1 in the low speed range. In Figure 7, a test run is carried out from a stopped state to check operation, followed by compaction work. As shown in Figure 7, the stopped states of Nos. 11-1 and 11-2 change to a preparation state for Nos. 12-1 to 12-5. The preparation state is a state in which a test run of the construction vehicle 1 is carried out. In other words, the preparation state is a state in which the construction vehicle 1 is driven at extremely low speed, extremely low speed, and low speed in the test yard to check whether the work equipment 20 and the like are operating normally. The vehicle speed increases in the order of extremely low speed, extremely low speed, low speed, medium speed, and high speed.

[0042] As shown in the rightmost column of FIG. 7, when the prime mover is turned on in the low speed range, the emergency braking device 10 is automatically turned on, and the emergency braking device 10 is also turned on during the standby states of Nos. 12-1 to 12-5.

[0043] Nos. 13-1 to 14-3 are work states in which the object to be compacted is actually compacted. During this work state, the vehicle speed is 0 to extremely low to low for Nos. 13-1 to 13-3. In this state, the vehicle speed is lower than the set value, so the function of the emergency braking device 10 remains ON from the ready state, as shown in the rightmost column of FIG. 7.

[0044] On the other hand, when the vehicle speed is medium or higher from No. 13-4 to No. 15-1 and compaction of the object to be compacted is being performed, the function of the emergency braking device 10 is turned off (see dotted line box A in the rightmost column of Figure 7). In other words, when the control device 13 determines that the vehicle speed has exceeded a preset value, it turns off the function of the emergency braking device 10 and notifies the operator via the alarm device 15 that the emergency braking device has been turned off. While the construction vehicle 1 is moving back and forth to compact the object to be compacted, it repeats the steps from No. 13-4 to No. 14-3.

[0045] After the vehicle speed exceeds a preset value, the construction vehicle 1 moves back and forth to compact the object to be compacted, while the emergency brake device 10 is turned OFF and the alarm device 15 notifies the operator that the emergency brake device has been turned OFF. As shown in No. 15-2, when the compaction work is completed and the vehicle comes to a complete stop, the emergency brake device 10 is switched from OFF to ON and the notification process for the operator is also terminated. When the work is completely completed and the prime mover is turned OFF in No. 15-3, the emergency brake device 10 is also turned OFF.

[0046] As shown in No. 14-1, when compaction work is being performed and the construction vehicle 1 changes direction back and forth, the vehicle speed momentarily becomes zero, but if the vehicle speed does not become zero for a predetermined time, the emergency brake device 10 remains OFF. On the other hand, if the vehicle speed remains at zero for a predetermined time period (when the control device 13 determines that the vehicle has completely stopped), the emergency brake device 10 is turned ON. The control device 13 determines that the vehicle has completely stopped when the vehicle speed remains at zero for a predetermined time period, when the forward / reverse lever is in the neutral position for a predetermined time period, or when the parking button that mechanically stops the vehicle is turned ON.

[0047] <Basic operation flow> Next, the operation flow of the emergency braking device 10 will be described. As shown in Fig. 8, the control device 13 determines whether or not the vehicle is in a low gear (step S11). If it is determined that the vehicle is in a low gear (Yes in step S11), the process proceeds to step S12. If it is determined that the vehicle is not in a low gear (= a high gear) (No in step S11), the function of the emergency braking device 10 is turned on (step S15).

[0048] Next, the control device 13 determines whether the vehicle speed is greater than a preset value (step S12). If it is determined that the vehicle speed is greater than the set value (Yes in step S12), the process proceeds to step S13. If it is determined that the vehicle speed is not greater than the set value (No in step S12), the function of the emergency braking device 10 is turned on (step S15).

[0049] Next, the control device 13 turns off the function of the emergency braking device 10 (step S13). At this time, the notification device 15 notifies the operator that the function of the emergency braking device 10 has been turned off.

[0050] Next, the control device 13 determines whether the vehicle has completely stopped (step S14). If it is determined that the vehicle has completely stopped (Yes in step S14), the control device 13 turns on the function of the emergency braking device 10 (step S15). If it is determined that the vehicle has not completely stopped (No in step S14), the process returns to step S13.

[0051] <About the effects> Here, when the vehicle is moving slowly from a stopped state, the speed is low, so the operator and workers working around the construction vehicle 1 are less attentive, making it relatively easy for a collision to occur. In this regard, with a construction vehicle 1 equipped with the emergency braking device 10 according to this embodiment, the function of the emergency braking device 10 is turned off when the vehicle speed is higher than a set value, thereby improving work efficiency. In other words, when the vehicle speed is relatively high, the operator and workers are also attentive, so the emergency braking device 10 is not activated, and work efficiency is emphasized. On the other hand, when the vehicle speed is below a set value, the function of the emergency brake device 10 can be turned ON to increase safety when the vehicle starts moving. In other words, safety can be increased by turning on the emergency brake device 10 when the attention of the operator and workers working around the construction vehicle 1 is reduced. Furthermore, because the vehicle is moving at a low speed, the vehicle can be stopped relatively quickly and damage to the object being compacted can be reduced.

[0052] Furthermore, in this embodiment, when the vehicle speed is greater than a set value, the function of the emergency braking device 10 is turned off and the operator is notified that the function of the emergency braking device 10 is turned off. This allows the operator to know that the emergency braking device 10 is not functioning.

[0053] Furthermore, the control device 13 determines that the vehicle has come to a complete stop when the vehicle speed remains at zero for a predetermined period of time, when the forward / reverse lever is in the neutral position for a predetermined period of time, or when the parking button that mechanically stops the vehicle is turned ON. This prevents the emergency braking device 10 from being switched ON / OFF every time the vehicle turns around during compaction work, which would otherwise make the control complicated. Furthermore, in this embodiment, the emergency braking device 10 is ON when the vehicle starts moving again after coming to a complete stop, thereby improving safety when starting to move again.

[0054] For example, in this embodiment, when the vehicle speed is greater than a set value in a low gear, the function of the emergency braking device 10 is turned OFF, and when the vehicle speed is equal to or less than the set value, the function of the emergency braking device is turned ON, but this mode may also be adopted when the vehicle is in a high gear.

[0055] Second Embodiment Next, a construction vehicle according to a second embodiment of the present invention will be described. In this embodiment, differences from the first embodiment will be mainly described. Figure 9 shows the operation flow of the emergency brake device of the construction vehicle according to the second embodiment of the present invention. In this embodiment, the presence or absence of an obstacle is determined before determining whether the vehicle speed is greater than a set value.

[0056] As shown in Fig. 9, in this embodiment, when the construction vehicle 1 is stopped, before determining whether or not it is in a low gear (step S11), the control device 13 determines whether or not an obstacle G has been detected (step S21). If it is determined that an obstacle G has not been detected (YES in step S21), the process proceeds to step S11. Step S11 and subsequent steps are the same as those in the first embodiment. If it is determined that an obstacle G has been detected (No in step S21), the function of the emergency braking device 10 is turned on (step S15).

[0057] For example, if an obstacle exists near the vehicle while the vehicle is stopped, extra caution is required when starting off. According to this embodiment, first it is determined whether an obstacle G has been detected, and if an obstacle G has been detected, the function of the emergency braking device 10 is turned ON (step S15). As a result, even when the construction vehicle 1 is in a state of starting to move and an obstacle G exists near the construction vehicle 1, safety can be improved by turning ON the function of the emergency braking device 10.

[0058] Third Embodiment Next, a construction vehicle according to a third embodiment of the present invention will be described. In this embodiment, differences from the second embodiment will be mainly described. Figure 10 shows the operation flow of the emergency brake device of the construction vehicle according to the third embodiment of the present invention. In this embodiment, it is determined whether the stopping position is inclined before determining whether the vehicle speed is greater than a set value.

[0059] The construction vehicle 1 according to the third embodiment is equipped with an inclination sensor (not shown) that detects the inclination angle of the vehicle. The detection result of the inclination sensor is sent to the control device 13 as inclination angle data. The control device 13 determines that the vehicle is on a "downhill slope" when the inclination angle of the vehicle is equal to or greater than a threshold value and the forward / reverse lever is tilted downward. A downhill slope refers to when the front of the vehicle is facing diagonally upward and the forward / reverse lever is tilted backward, or when the front of the vehicle is facing diagonally downward and the forward / reverse lever is tilted forward. The control device 13 can determine whether the vehicle is on a downhill slope based on the input direction of the forward / reverse lever and the inclination sensor.

[0060] 10, in this embodiment, when the construction vehicle 1 is stopped, the control device 13 determines whether an obstacle G has been detected (step S21). If it is determined in step S21 that an obstacle G has been detected (No in step S21), the function of the emergency brake device is turned on (step S15).

[0061] If it is determined in step S21 that an obstacle G has not been detected (Yes in step S21), the control device 13 determines whether or not the road is on a downhill slope (step S31). If it is determined that the road is on a downhill slope (Yes in step S31), the process proceeds to step S12. On the other hand, if it is determined that the road is not on a downhill slope (No in step S31), the process proceeds to step S11. Step S11 and subsequent steps are the same as those in the second embodiment.

[0062] For example, if the vehicle's inclination angle is equal to or greater than the threshold when it is stopped and it is about to start moving downhill, the vehicle's speed when it starts moving will be greater than on flat ground. This increases the braking distance, and even if the emergency brake device is turned on, the vehicle may not be able to stop within the expected time frame, which could make it difficult to ensure safety.

[0063] In this regard, according to this embodiment, if it is determined that the road is downhill (Yes in step S31), step S11 is skipped and it is determined whether the vehicle speed is greater than a set value (step S12). When traveling downhill, the function of the emergency braking device is turned off before the braking limit of the emergency braking device (FIG. 5) is exceeded, and the operator is notified of the performance limit of the emergency braking device (the function of the emergency braking device is turned off) early, and the operator is encouraged to take emergency stopping measures without relying on the emergency braking device, thereby ensuring safety.

[0064] It is also preferable to set the value in step S12 to be smaller as the vehicle tilt angle increases, thereby notifying the operator of the performance limit of the emergency braking device (the function of the emergency braking device is OFF) earlier and encouraging the operator to take emergency stopping measures without relying on the emergency braking device, thereby ensuring greater safety. [Explanation of symbols]

[0065] 1. Construction vehicles 2. Body 3 Tires 10 Emergency braking system 11 Vehicle speed sensor 12 Obstacle Sensor 13 Control device 14 Braking device 15. Alarm device G Obstacle

Claims

1. A construction vehicle equipped with an emergency braking device, The emergency braking device an obstacle sensor that detects an obstacle; a control device including a determination unit that determines the presence or absence of an obstacle based on the obstacle sensor; a vehicle speed sensor that measures a vehicle speed and outputs vehicle speed data to the control device; a braking device that applies an emergency brake to the vehicle when the determination unit determines that there is an obstacle, If the vehicle speed is greater than a set value, the function of the emergency braking device is turned off and an operator is notified that the function of the emergency braking device is turned off; When the vehicle speed is equal to or lower than a set value, the function of the emergency brake device is turned on; A construction vehicle characterized in that, after the function of the emergency brake device is turned OFF, if it is determined that the vehicle has come to a complete stop, the function of the emergency brake device is turned ON.

2. a forward / reverse lever for switching between forward and reverse movement of the vehicle and for applying a brake when in a neutral position; 2. The construction vehicle according to claim 1, wherein the vehicle is determined to have come to a complete stop when the vehicle speed becomes zero for a predetermined period of time, when the forward / reverse lever is in the neutral position for a predetermined period of time, or when a parking button that mechanically stops the vehicle is turned ON.

3. When the vehicle is stopped, determining whether or not an obstacle is present before determining whether or not the vehicle speed is greater than the set value; 2. The construction vehicle according to claim 1, wherein when the determining unit determines that an obstacle is present, the function of the emergency brake device is turned on.

4. an inclination sensor that measures an inclination angle of the vehicle and outputs inclination angle data to the control device; When the vehicle is stopped, determining whether the stopping position is inclined before determining whether the vehicle speed is greater than the set value; 2. The construction vehicle according to claim 1, wherein if it is determined that the stopping position of the vehicle is inclined, it is determined whether the vehicle speed is greater than the set value.

5. 5. The construction vehicle according to claim 4, wherein the set value is set to be smaller as the tilt angle of the vehicle increases.

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