JP5818154B2 - Cab attitude control device - Google Patents

Description

  The present invention relates to a cab attitude control device for a cab-over type vehicle.

  Japanese Utility Model Laid-Open No. 60-110625 discloses a grill opening and closing device. In this device, focusing on the fact that the air resistance coefficient increases almost in proportion to the increase in the flow rate of the internal flow flowing into the engine room, when the water temperature of the radiator exceeds a predetermined temperature, the openings of the upper grill and the under grill are opened. When the temperature falls below a predetermined temperature, the opening of the upper grill and the under grille are closed, and the flow rate of the internal flow taken from the grill is limited to an amount necessary to prevent overheating of the engine, thereby reducing the air resistance and improving the fuel efficiency of the vehicle. .

  Japanese Patent Application Laid-Open No. 2004-291765 describes a cab height control device that improves the cooling performance of a radiator. In order to maintain a good ride even when the number of passengers, load capacity, etc. change during normal driving, this device adjusts the height of the cab air suspension so that the cab is positioned at the neutral position. Control. Further, when the water temperature of the radiator exceeds a predetermined temperature, the height of the cab air suspension is controlled to raise the cab upward from the neutral position. As a result, the clearance of the traveling wind intake opening between the cab grille and the bumper is increased, the amount of traveling wind flowing into the radiator is increased, and the cooling performance of the radiator is improved. And when the water temperature of a radiator becomes below predetermined temperature, a cab is lowered | hung to a neutral position.

Japanese Utility Model Publication No. 60-110625 JP 2004-291765 A

  In the device disclosed in Patent Document 1, a dedicated opening / closing mechanism for opening / closing the opening on the front surface of the vehicle is separately provided. Therefore, it is necessary to increase the number of parts and cost, and to secure a space for arranging the opening / closing mechanism. Further, when the water temperature of the radiator exceeds a predetermined temperature, the upper grille and the under grille are opened without considering the increase in the air resistance. For example, the flow rate of the internal flow is increased during high-speed traveling where the influence of the air resistance is large. In addition, the deterioration in fuel efficiency due to an increase in air resistance may exceed the improvement in fuel efficiency due to an improvement in the cooling performance of the radiator, which may worsen the fuel efficiency of the vehicle that is running.

  On the other hand, since the cooling performance of the radiator is improved by using the cab attitude control for maintaining a good ride comfort, the device of Patent Document 2 requires a dedicated mechanism as in Patent Document 1 above. And not. However, in order to improve the cooling performance of the radiator, the amount of traveling wind (internal flow) flowing into the radiator by increasing the cab is increased, so that, similarly to the device of Patent Document 1, the influence of air resistance is large. In the running state, the deterioration of the fuel consumption due to the increase in air resistance may exceed the improvement of the fuel consumption due to the improvement of the cooling performance of the radiator, which may worsen the fuel consumption of the running vehicle.

  SUMMARY OF THE INVENTION Accordingly, an object of the present invention is to provide a cab attitude control device capable of controlling the opening and closing of a cab front opening suitable for fuel efficiency of a vehicle in a high-speed traveling state where the influence of air resistance is large.

In order to achieve the above object, a cab attitude control device of the present invention includes a cab, a cab suspension, a vehicle body side member, a front opening, a cooler, vehicle speed detection means, cooling capacity determination means, cab height. Control means. The cab is disposed above the front part of the vehicle body frame of the vehicle. The cab suspension supports the cab so as to be movable up and down with respect to the vehicle body frame so that at least the front end portion of the cab is raised and lowered. The vehicle body side member is fixed to the vehicle body frame in front of the cab. The front opening of the cab is provided in the front of the cab, and the overlapping range in the vehicle front-rear direction with the vehicle body side member increases in accordance with the lowering of the front end of the cab from a predetermined reference position, and the front end of the cab from the reference position The overlapping range in the vehicle front-rear direction with the vehicle body side member decreases as the portion rises. The cooler is disposed at the rear of the cab front opening and cools the engine of the vehicle by radiating heat to the air flowing from the cab front opening. The vehicle speed detection means detects the vehicle speed of the vehicle. The cooling capacity determination means determines whether or not there is a margin in the cooling capacity of the cooler. The cab height control means controls the cab suspension to raise and lower only the front end of the cab. Further, the cab height control means is configured such that the vehicle speed detected by the vehicle speed detection means is equal to or lower than the first predetermined speed, and that the vehicle speed detected by the vehicle speed detection means exceeds the first predetermined speed and the cooling of the cooler is performed. When the cooling capacity determining means determines that there is no capacity, the cab is set to the reference position, the vehicle speed detected by the vehicle speed detecting means exceeds the first predetermined speed, and the cooling capacity of the cooler has room. When the cooling capacity determination means determines, the front end of the cab is lowered from the reference position.

  In the above configuration, when the cab height control means raises the front end of the cab of the running vehicle, the opening area of the cab front opening increases, and the amount of air flowing from the cab front opening and passing through the cooler Will increase. For this reason, the heat dissipation amount of the cooling water is increased and the cooling capacity of the cooler is improved, but the air resistance of the vehicle is increased. Although the improvement of the cooling capacity contributes to the improvement of the fuel consumption performance, the increase of the air resistance becomes a factor for the reduction of the fuel consumption performance.

  Conversely, when the cab height control means lowers the front end of the cab of the traveling vehicle, the opening area of the cab front opening decreases, and the amount of air flowing from the cab front opening decreases. For this reason, the air resistance of the vehicle decreases, but the cooling capacity of the cooler decreases. A decrease in air resistance contributes to an improvement in fuel efficiency, but a decrease in cooling capacity is a cause of a decrease in fuel efficiency.

  The effect of vehicle air resistance on fuel efficiency varies greatly depending on the vehicle running speed.Therefore, when opening / closing the cab front opening is controlled in consideration of vehicle fuel efficiency, the vehicle air resistance is reduced and the cooling capacity of the cooler is reduced. Which priority is given to improvement depends on the traveling speed of the vehicle.

  In this regard, in the above configuration, when the vehicle speed is in a high-speed traveling state exceeding the first predetermined speed, even if the cooling capacity determination means determines that the cooling capacity of the cooler has no margin, the cab height The control means maintains the cab at the reference position. That is, in the high-speed traveling state where the influence of the air resistance of the vehicle is large, the opening on the cab front surface is controlled with priority on the reduction of the air resistance of the vehicle over the improvement of the cooling capacity of the cooler. For this reason, the air resistance does not increase and the fuel efficiency improves as compared with the case where the cab is raised with priority given to the improvement of the cooling capacity of the cooler.

  In addition, when the vehicle is in a high-speed running state and the cooling capacity determination means determines that the cooling capacity of the cooler is sufficient, the cab height control means prioritizes the reduction of air resistance and the front end of the cab Is lowered from the reference position to reduce the air resistance, so that the fuel efficiency of the vehicle is improved as compared with the case where the cab is maintained at the reference position.

  As described above, according to the above configuration, the opening / closing control of the front opening of the cab suitable for the fuel efficiency of the vehicle in a high-speed driving state in which it is preferable to prioritize the reduction of the air resistance of the vehicle over the securing of the cooling capacity of the cooler. It can be performed.

  The cab height control means determines that the vehicle speed detected by the vehicle speed detection means is equal to or lower than a second predetermined speed that is less than the first predetermined speed and that the cooling capacity of the cooler has no margin. In this case, the front end portion of the cab may be raised from the reference position.

  In the above configuration, when the cooling capacity determining means determines that the cooling capacity of the cooler has no margin in the low speed traveling state where the vehicle speed is less than the second predetermined speed and less than the first predetermined speed, the cab height control means The front end of the is raised from the reference position. That is, in the low-speed traveling state where the influence of the air resistance of the vehicle is small, the opening of the cab front surface is controlled with priority given to the improvement of the cooling capacity of the cooler over the reduction of the air resistance of the vehicle. As a result, the cooling capacity of the cooler is improved and the fuel efficiency of the vehicle is improved.

  Thus, according to the above configuration, the opening and closing of the cab front opening suitable for the fuel efficiency of the vehicle can be achieved even in a low-speed traveling state where it is preferable to prioritize the improvement of the cooling capacity of the cooler over the reduction of the air resistance of the vehicle. Control can be performed.

  In addition, temperature detection means for detecting the temperature of the cooling medium circulating between the cooler and the engine at a predetermined circulation position is provided, and the cooling capacity determination means is configured such that the temperature of the cooling medium detected by the temperature detection means is a predetermined temperature. May exceed the cooling capacity of the cooler, and may determine that the cooling capacity of the cooler has a margin when the temperature of the cooling medium is equal to or lower than a predetermined temperature.

  In the above configuration, the cooling capacity determination unit determines whether or not the cooling capacity of the cooler has a margin based on the temperature of the cooling medium. Therefore, the cooling capacity of the cooler can be determined with a simple configuration, and the calculation load of the cab attitude control device is reduced.

  According to the present invention, it is possible to perform opening / closing control of the cab front surface opening that is suitable for the fuel efficiency of the vehicle in a high-speed traveling state where the influence of air resistance is large.

It is a block diagram which shows the principal part of the vehicle provided with the cab attitude | position control apparatus concerning this invention. It is a side view which shows the principal part of the vehicle provided with the cab attitude | position control apparatus concerning this invention. It is a schematic diagram of the vehicle front surface provided with the cab attitude | position control apparatus concerning this invention. It is a flowchart which shows a cab attitude | position control process. It is a schematic diagram of the vehicle side surface when a cab exists in a reference position. It is a schematic diagram of the vehicle side surface when raising a cab. It is a schematic diagram of the vehicle side surface when a cab is lowered. It is a schematic diagram of the vehicle side surface when the cab is tilted forward. It is a schematic diagram of the vehicle side surface when the cab is tilted backward.

  Hereinafter, an embodiment of the present invention will be described with reference to the drawings. In the figure, FR indicates the front of the vehicle, and UP in the figure indicates the upper side of the vehicle. Further, in the following description, the front-rear direction means the front-rear direction of the vehicle, and the left-right direction means the left-right direction in a state facing the front of the vehicle.

  As shown in FIG. 2, the cab overtrack (vehicle) 1 according to this embodiment includes a cab 2, a main frame (body frame) 3, a front bumper 4, a radiator (cooler) 6, and a cab suspension 8. A cab controller 11, a vehicle speed sensor 12 (vehicle speed detection means), a cooling water temperature sensor 13 (temperature detection means), an ECU 14 and the like.

  The main frame 3 extends in the vehicle front-rear direction on both sides of the vehicle 1 in the vehicle width direction, and the front end portions of the left and right main frames 3 are connected by a cross member (not shown).

  The front bumper 4 has a plate shape that is supported by a bumper stay (not shown) that extends forward from the front end of each of the left and right main frames 3 and extends in the vehicle width direction.

  The cab 2 is disposed above the front portion of the main frame 3. A grid-like front grille 5 serving as a front opening is provided at the center below the front surface of the cab 2, and air is taken into the vehicle body from the front of the vehicle (in the direction of the arrow in FIG. 2) through the front grill 5 during traveling. It is.

  The radiator 6 is disposed behind the front grill 5. Air taken from the front of the vehicle through the front grille 5 passes through the radiator 6. Cooling water (cooling medium) that has become a high temperature as a result of cooling the engine 7 flows into the radiator 6, dissipates heat to the air flow passing through the radiator 6, reduces the temperature, and circulates the engine 7 again to circulate the engine 7. Cool down. When the amount of air passing through the radiator 6 increases, the amount of heat dissipated from the cooling water increases, the temperature of the cooling water decreases, and the cooling capacity of the radiator 6 improves. On the contrary, when the amount of air passing through the radiator 6 is reduced, the amount of heat released from the cooling water is reduced, the temperature drop of the cooling water is reduced, and the cooling capacity of the radiator 6 is reduced.

  The cab suspension 8 includes a pair of left and right front air springs 9 arranged in the vehicle width direction on the main frame 3 side facing the front end bottom of the cab 2 and a main frame 3 side facing the rear end bottom of the cab 2. It consists of a pair of left and right rear air springs 10 arranged in the width direction. The front air spring 9 and the rear air spring 10 are filled with compressed air to form an air spring, the lower end portions are fixed to the main frame 3 side, and the upper end portions respectively correspond to the bottom portion 17 of the cab 2. It is supported so that it can move up and down from below, and absorbs vibrations from the running road surface and the vehicle body.

  The cab controller 11 controls the height of the cab 2 in the vertical direction so that the height from the main frame 3 to the cab 2 becomes a predetermined height (reference position) set in advance. That is, even when the height of the cab 2 fluctuates due to a change in the load weight of the cab 2 due to an increase or decrease in the number of passengers, the cab controller 11 adjusts the air pressure of the front air suspension 9 and the rear air suspension 10 to The height of 2 is always controlled to the reference position to maintain a good ride comfort for the passenger. At this reference position, as shown in FIGS. 2 and 5, the vertical height of the upper end of the front grill 5 is higher than the vertical height of the upper end of the front bumper 4. The vertical height of the lower end portion is set lower than the vertical height of the upper end portion of the front bumper 4, and the front bumper 4 and the front grille 5 overlap each other in the vehicle front-rear direction. The cab controller 11 also controls the height of the cab 2 according to the signal even when receiving a signal from a cab attitude control unit 16 described later.

  The vehicle speed sensor 12 detects the vehicle speed V (m / s) of the vehicle 1 and outputs the detected vehicle speed V to the ECU 14.

  The cooling water temperature sensor 13 detects the cooling water temperature T (° C.) near the inlet (predetermined circulation position) of the cooling water that circulates through the engine 7 and flows into the radiator 6 and outputs the detected temperature to the ECU 14.

  The ECU 14 includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory). The CPU functions as a cooling capacity determination unit 15 and a cab posture control unit 16 described later by reading a program stored in the ROM and executing a cab posture control process. The RAM functions as a storage area for the vehicle speed V detected by the vehicle speed sensor 12 and the cooling water temperature T detected by the temperature detection sensor 13, a temporary storage area for CPU calculation results, and a setting area for various determination reference values described later.

  The cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 has no allowance when the cooling water temperature T exceeds a predetermined temperature T1, and the cooling water temperature T is equal to or lower than the predetermined temperature T1. It is determined that the cooling capacity of the radiator 6 is sufficient. That is, the cooling capacity determination unit 15 constitutes cooling capacity determination means that determines whether or not the cooling capacity of the radiator 6 has a margin based on the cooling water temperature T detected by the cooling water temperature sensor 13.

  The cab attitude control unit 16 controls the height of the cab 2 by sending a signal to the cab controller 11. That is, when the vehicle speed V is smaller than the first predetermined speed V1 set in advance, a signal is sent to the cab controller 11 to set the cab 2 to the reference position (see FIG. 5). If the vehicle speed V exceeds the first predetermined speed V1 and the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 is sufficient, a signal is sent to the cab controller 11 to move the cab 2 from the reference position. It is lowered to a predetermined lowered position (see FIG. 6). Furthermore, when the vehicle speed V is less than the first predetermined speed V1 and smaller than the second predetermined speed V2 set in advance, and the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 has no margin, A signal is sent to the cab controller 11 to raise the cab 2 from the reference position to a predetermined raised position (see FIG. 7). That is, the cab attitude control unit 16 constitutes a cab height control unit that controls the attitude of the cab 2 based on the vehicle speed V of the vehicle 1 detected by the vehicle speed sensor 12 and the determination result of the cooling capacity determination unit 15.

  Next, the cab attitude control process executed by the ECU 14 will be described based on the flowchart of FIG. This process is executed every predetermined time while the vehicle 1 is traveling. The ECU 14 first acquires the vehicle speed V and the coolant temperature T of the vehicle 1 (step S1). Subsequently, the ECU 14 determines whether or not the vehicle speed V exceeds the first predetermined speed V1 (step S2). When the vehicle speed V is in a high speed running state exceeding V1, the process proceeds to step S3, and when the vehicle speed V is a medium speed or low speed traveling state equal to or less than V1, the process proceeds to step S5. In step S3, it is determined whether or not the cooling water temperature T is equal to or lower than a predetermined temperature T1. When the cooling water temperature T is equal to or lower than T1, the cooling capacity of the radiator 6 has a margin, so the process proceeds to step S4 and the cab 2 is lowered from the reference position to a predetermined lowered position. If the cooling water temperature T exceeds T1, the cooling capacity of the radiator 6 is not sufficient, and the process proceeds to step S8. When it progresses to step S5, it is determined whether the vehicle speed V is below the 2nd predetermined speed V2. If the vehicle speed V is a low-speed traveling state with V2 or less, the process proceeds to step S6. If the vehicle speed V is a medium-speed traveling state exceeding V2, the process proceeds to step S8. In step S6, it is determined whether or not the temperature T of the cooling water exceeds a predetermined temperature T1. When the temperature T of the cooling water exceeds T1, the radiator 6 has no room, so the process proceeds to step S7, and the cab 2 is raised from the reference position to a predetermined ascent position. In step S8, the cab 2 is set to the reference position.

  In the present embodiment, as shown in FIG. 7, when the cab attitude control unit 16 raises the cab 2 from the reference position to a predetermined ascending position, the overlapping range in the front-rear direction between the front bumper 4 and the front grill 5 decreases. The opening area of the front surface of the cab 2 increases (C state in FIG. 3). As a result, the amount of air flowing in from the front grill 5 and passing through the radiator 6 is increased and the cooling capacity of the radiator 6 is improved, but the air resistance of the vehicle 1 is increased. Although the improvement of the cooling capacity of the radiator 6 contributes to the improvement of the fuel efficiency, the increase of the air resistance becomes a factor of decreasing the fuel efficiency.

  On the other hand, as shown in FIG. 6, when the cab attitude control unit 16 lowers the cab 2 from the reference position to a predetermined lowered position, the range in which the front bumper 4 and the front grill 5 overlap in the front-rear direction increases. The opening area of the front surface of the cab 2 is reduced (state B in FIG. 3), and the amount of air flowing from the front grill 5 is reduced. For this reason, although the air resistance of the vehicle 1 decreases, since the amount of air passing through the radiator 6 decreases, the cooling capability of the radiator 6 decreases. A decrease in air resistance contributes to an improvement in fuel efficiency, but a decrease in cooling capacity is a cause of a decrease in fuel efficiency.

  Since the influence of the air resistance of the vehicle 1 on the fuel consumption varies greatly depending on the travel speed V of the vehicle 1, when the height of the cab 2 is controlled in consideration of the fuel consumption performance of the vehicle 1, the reduction of the air resistance of the vehicle 1 and the radiator Which of the six cooling capacity improvements has priority depends on the traveling speed V of the vehicle 1.

  In this regard, in the present embodiment, when the vehicle speed V of the vehicle 1 is equal to or lower than the first predetermined speed V1, the cab attitude control unit 16 sets the cab 2 to the reference position (state A in FIGS. 5 and 3). ). Further, when the vehicle speed V exceeds the first predetermined speed V1, even if the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 is not sufficient, the cab attitude control unit 16 The cab 2 is maintained at the reference position. That is, in the high-speed traveling state where the influence of the air resistance of the vehicle 1 is large, the height of the cab 2 is controlled with priority on the reduction of the air resistance of the vehicle 1 over the improvement of the cooling capacity of the radiator 6. For this reason, priority is given to the improvement of the cooling capacity of the radiator 6, and the air resistance does not increase as compared with the case where the cab 2 is raised from the reference position, and the fuel efficiency is improved.

  Further, when the vehicle 1 is in a high-speed traveling state and the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 is sufficient, the cab attitude control unit 16 gives priority to the reduction of the air resistance, and the cab 2 Is lowered to a predetermined lowered position to reduce the air resistance, so that the fuel efficiency of the vehicle 1 is improved as compared with the case where the cab 2 is maintained at the reference position.

  Thus, according to the present embodiment, the high cab 2 suitable for the fuel consumption performance of the vehicle 1 in a high-speed traveling state in which it is preferable to prioritize the reduction of the air resistance of the vehicle 1 over the securing of the cooling capacity of the radiator 6. Can be controlled.

  In addition, when the vehicle speed V of the vehicle 1 is less than the first predetermined speed V1 and the vehicle is traveling at a low speed of the second predetermined speed V2 or less, the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 has no margin, The cab attitude control unit 16 raises the cab 2 from the reference position to a predetermined ascent position. That is, in the low-speed traveling state where the influence of the air resistance of the vehicle 1 is small, the height of the cab 2 is controlled with priority given to the improvement of the cooling capacity of the radiator 6 over the reduction of the air resistance of the vehicle 1. As a result, the cooling capacity of the radiator 6 is improved and the fuel efficiency of the vehicle 1 is improved.

  Thus, according to the present embodiment, the cab 2 suitable for the fuel consumption performance of the vehicle 1 can be achieved even in a low-speed traveling state in which priority is given to improving the cooling capacity of the radiator 6 over reduction of the air resistance of the vehicle 1. Height control can be performed.

  The cooling capacity determination unit 15 determines whether or not the cooling capacity of the radiator 6 has a margin based on the temperature T of the cooling water detected by the cooling water temperature sensor 13, so that the cooling of the radiator 6 can be performed with a simple configuration. The ability can be determined, and the calculation load of the ECU 14 is reduced.

  In the present embodiment, the cab suspension 8 and the cab controller 11 that control the cab posture of the vehicle 1 are used to move the cab 2 up and down to increase or decrease the opening area of the cab front opening. It is not necessary to separately provide an opening / closing mechanism for the opening on the front surface of the vehicle such as a mechanism, and the fuel efficiency of the vehicle 1 can be improved with less cost.

  Note that when the vehicle speed V of the vehicle 1 is in a high speed traveling state exceeding the first predetermined speed V1 and the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 is sufficient, the cab attitude control unit 16 Only the front end portion of the cab 2 may be lowered from the reference position, and the cab 2 may be in a forward inclined posture as shown in FIG. In this case, the range in which the front bumper 4 and the front grille 5 overlap in the front-rear direction increases, and the opening area of the front surface of the cab 2 decreases (state B in FIG. 3). As a result, the air resistance of the vehicle 1 is reduced, and the fuel efficiency of the vehicle 1 is improved as compared with the case where the cab 2 is maintained at the reference position.

  Further, the vehicle speed V of the vehicle 1 is lower than the first predetermined speed V1 and is in a low speed traveling state below the second predetermined speed V2, and the cooling capacity determination unit 15 determines that the cooling capacity of the radiator 6 has no margin. In this case, the cab posture control unit 16 may raise only the front end portion of the cab 2 from the reference position, and as shown in FIG. In this case, the overlapping range of the front bumper 4 and the front grille 5 in the front-rear direction decreases, and the opening area of the front surface of the cab 2 increases (state C in FIG. 3). As a result, the cooling capacity of the radiator 6 is improved and the fuel efficiency of the vehicle 1 is improved.

  Moreover, the detection position (predetermined circulation position) of the cooling water temperature T is not limited to this embodiment, For example, the temperature of the cooling water circulating through the engine 7 may be detected. In this case, in order to determine whether or not the cooling capacity of the radiator 6 has a margin, a predetermined temperature corresponding to the detection position of the coolant temperature is set in advance.

  Further, the cab suspension 8 is not limited to the air springs 9 and 10 and may be constituted by, for example, a hydraulic spring.

  Further, the vehicle body side member that overlaps the front grille 5 in the front-rear direction is not limited to the front bumper 4 and may be a bumper cover, for example.

  Moreover, what is necessary is just to add and install the apparatus (unit) which performs this process with respect to the existing vehicle provided with the cab controller which performs the attitude | position control of a cab. When the existing vehicle includes a vehicle speed sensor and a coolant temperature sensor, the vehicle speed sensor 12 and the coolant temperature sensor 13 used in this embodiment can be shared. As described above, the present invention can be easily applied to the existing vehicle at a low cost.

  As mentioned above, although the embodiment to which the invention made by the present inventor is applied has been described, the present invention is not limited by the discussion and the drawings that form part of the disclosure of the present invention according to this embodiment. That is, it is needless to say that other embodiments, examples, operation techniques, and the like made by those skilled in the art based on this embodiment are all included in the scope of the present invention.

1 Vehicle 2 Cab 3 Main frame (body frame)
4 Front bumper (vehicle side member)
5 Front grille (front opening)
6 Radiator (cooler)
8 Cab suspension 11 Cab controller 12 Vehicle speed sensor (vehicle speed detection means)
13 Cooling water temperature sensor (temperature detection means)
15 Cooling capacity determination unit (cooling capacity determination means)
16 Cab attitude control unit (cab height control means)

Claims (3)

A cab disposed above the front of the vehicle body frame;
A cab suspension that supports the cab so as to be vertically movable with respect to the vehicle body frame so that at least a front end portion of the cab is raised and lowered;
A vehicle body side member fixed to the vehicle body frame in front of the cab in the vehicle;
A front end portion of the cab from the reference position is provided on the front surface of the cab, and an overlapping range in the vehicle front-rear direction with the vehicle body side member increases in accordance with the lowering of the front end portion of the cab from a predetermined reference position. A front opening of the cab in which the overlapping range in the vehicle front-rear direction with the vehicle body side member decreases in accordance with the rise of
A cooler that is disposed behind the cab front opening and cools the vehicle engine by radiating heat to the air flowing in from the cab front opening;
Vehicle speed detecting means for detecting the vehicle speed of the vehicle;
Cooling capacity determination means for determining whether or not the cooling capacity of the cooler has a margin;
Cab height control means for controlling the cab suspension to raise and lower only the front end of the cab,
The cab height control means is configured such that the vehicle speed detected by the vehicle speed detection means is equal to or lower than a first predetermined speed, and the vehicle speed detected by the vehicle speed detection means exceeds the first predetermined speed and the cooling When the cooling capacity determining means determines that the cooling capacity of the vessel has no margin, the cab is set to the reference position, the vehicle speed detected by the vehicle speed detecting means exceeds the first predetermined speed, and the The cab attitude control device characterized in that, when the cooling capacity determination means determines that the cooling capacity of the cooler is sufficient, the front end of the cab is lowered from the reference position. The cab attitude control device according to claim 1,
The cab height control means is the cooling capacity determination means if the vehicle speed detected by the vehicle speed detection means is less than or equal to a second predetermined speed that is less than the first predetermined speed and the cooling capacity of the cooler has no margin. If determined, the cab attitude control device raises the front end of the cab from the reference position. The cab attitude control device according to claim 1 or 2,
A temperature detecting means for detecting a temperature of a cooling medium circulating between the cooler and the engine at a predetermined circulation position;
The cooling capacity determining means determines that the cooling capacity of the cooler has no margin when the temperature of the cooling medium detected by the temperature detecting means exceeds a predetermined temperature, and the temperature of the cooling medium is the predetermined temperature. If the temperature is equal to or lower than the temperature, it is determined that the cooling capacity of the cooler has a margin.

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