Refrigerated / freezer truck

Abstract

To provide a refrigeration / freezing car capable of acquiring a stable erroneous start suppression effect irrespective of an actuation situation of a refrigerator / freezer.SOLUTION: A refrigeration / freezing car (1) includes: an engine control part (10) for controlling an engine (12) according to a torque request; and a refrigerator / freezer (2) for performing cooling by a compressor (22) which actuates by an output of the engine. The refrigeration / freezing car has a function (30) for suppressing engine torque in the case where an accelerator pedal is operated in the state where an obstacle is detected within a predetermined distance in a traveling direction at equal to or less than a predetermined low car speed. At the time of actuation of the function for suppressing the engine torque, a torque request value allocated to the compressor is made to be constant or zero.SELECTED DRAWING: Figure 2

Description

[Technical Field]

[0001] The present invention relates to a refrigerated / freezer vehicle, and more particularly to a refrigerated / freezer vehicle having a false start suppression function. [Background technology]

[0002] Refrigerated vehicles that use engine output to operate a refrigeration cycle are well known. For example, Patent Document 1 discloses a technology that aims to always obtain stable cooling performance by setting the inverter frequency to a value higher than an allowable value when the engine speed is below a set value, thereby enabling the compressor to continue operating even when the engine speed drops. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent No. 4199380 Summary of the Invention [Problem to be solved by the invention]

[0004] In a refrigerated vehicle, the effect on engine torque changes depending on the freezer's temperature setting, or when cooling capacity is required, such as after the door is opened or closed or immediately after the switch is turned on. Therefore, if the false start suppression function is activated when engine torque is reduced due to the load of the freezer, there is a risk that the amount of engine torque reduction will be too large.

[0005] For example, if the accelerator pedal is accidentally depressed when there is a parked vehicle ahead and the false start prevention function is activated, then if the vehicle is on an uphill slope, a level of engine torque is required to prevent the vehicle from rolling backward. However, if the engine torque reduction amount becomes too large due to the load on the freezer, there is a risk that the vehicle will roll backward. If the torque reduction amount is set to a small amount in preparation for this, then the false start prevention function may be impaired depending on the situation.

[0006] The present invention has been made in consideration of the above-mentioned circumstances, and its object is to provide a refrigerated vehicle that can achieve a stable effect of suppressing erroneous starts regardless of the operating status of the refrigerator / freezer compartment. [Means for solving the problem]

[0007] In order to solve the above problems, the present invention provides: an engine control unit that controls the engine in response to a torque request; a refrigerator / freezer that performs refrigeration / cooling using a compressor operated by the output of the engine; A refrigerated / freezer vehicle equipped with A system that has a function to suppress engine torque when the accelerator pedal is operated while an obstacle is detected within a predetermined distance in the direction of travel at a vehicle speed below a predetermined low speed, The refrigerated / freezer vehicle is characterized in that, when the engine torque suppression function is activated, the torque request value allocated to the compressor is set to a constant value or to zero. [Effects of the Invention]

[0008] As described above, the refrigerated / freezer vehicle of the present invention is expected to have a stable effect of suppressing false starts regardless of the operating status of the refrigerator / freezer by setting the torque requirement value assigned to the refrigerator / freezer compressor to a constant value or to zero when the engine torque suppression function is activated. [Brief explanation of the drawings]

[0009] [Figure 1] FIG. 1 is a side view showing an outline of a refrigerated / freezer vehicle. [Figure 2] FIG. 1 is a block diagram showing a control system for a refrigerated / freezer vehicle. [Figure 3] 4 is a flowchart showing erroneous start suppression control according to the first embodiment of the present invention. [Figure 4] 10 is a flowchart showing erroneous start suppression control according to a second embodiment of the present invention. [Figure 5] 10 is a flowchart showing erroneous start suppression control according to a third embodiment of the present invention. [Figure 6] 10 is a flowchart showing erroneous start suppression control according to a fourth embodiment of the present invention. DETAILED DESCRIPTION OF THE INVENTION

[0010] Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. (Basic configuration of refrigerated / freezer truck) In Figure 1, refrigerated / freezer vehicle 1 is a cab-over truck with an internal combustion engine 12 mounted below the passenger compartment, and is provided with a refrigerator / freezer 2 at the rear of the vehicle body. Refrigerated / freezer 2 is configured as a container with an insulated structure using, for example, insulating material, and is provided with an opening / closing door at the rear and / or side.

[0011] The refrigeration system of the refrigerator / freezer 2 comprises a compressor 22 driven by the power of the engine 12, a condenser 23 and a receiver-drier 24 mounted on the lower rear side of the vehicle body, and an evaporator 25 arranged on the ceiling of the refrigerator / freezer 2, which are connected by piping to circulate the refrigerant and perform a refrigeration cycle (compression, condensation, expansion, evaporation) to cool the interior of the compartment.

[0012] The compressor 22 that compresses the refrigerant has an electromagnetic clutch attached to a pulley that is belt-driven by the engine 12, and the electromagnetic clutch is controlled on / off by the refrigerator / freezer control unit 20 based on the temperature inside the refrigerator / freezer 2 detected by a temperature sensor installed in the refrigerator / freezer 2, thereby switching the operation / non-operation of the compressor 22 (cooling on / off) and maintaining the temperature inside the refrigerator at a predetermined range.

[0013] Figure 2 shows the control system of the refrigerated / freezer vehicle 1. When the cooling switch on the operation unit 21 (control panel) of the refrigerator / freezer 2 is turned on while the engine 12 is running, the refrigerator / freezer control unit 20 turns on the electromagnetic clutch based on the set temperature and the temperature inside the compartment to operate the compressor 22, and also operates the fan motor of the condenser 23 and the fan motor of the evaporator 25, causing the refrigerator / freezer 2 to enter an operating state and cooling the air inside the compartment.

[0014] The refrigerated / freezer vehicle 1 is equipped with an electronically controlled throttle system configured such that the opening of the throttle valve (throttle motor) of the engine 12 is controlled by an engine controller 10 in accordance with the accelerator pedal depression amount (torque demand) detected by an accelerator pedal sensor 11. In addition to the accelerator pedal depression amount, the engine controller 10 acquires various detection values ​​indicating the operating state of the engine 12 and the running state of the vehicle, and maintains the operating state of the engine 12 optimally.

[0015] For example, even when idling, if the cooling switch of the refrigerator / freezer 2 is turned on and the compressor 22 is operating, the engine controller 10 controls the throttle opening in response to a torque request from the refrigerator / freezer control unit 20 so that the output of the engine 12 corresponds to the load on the compressor 22. Also, by reducing the driver's accelerator operation, i.e., the torque request value allocated to the accelerator pedal sensor 11, in accordance with the torque request value allocated to the refrigerator / freezer 2 (compressor 22), the output of the engine 12 is efficiently distributed between driving and cooling.

[0016] (False start suppression control) The refrigerated / freezer vehicle 1 having the basic configuration described above is equipped with an erroneous start prevention control unit 30 for executing erroneous start prevention control. The erroneous start prevention control unit 30 acquires the distance to an obstacle detected by the obstacle detection means 31, the vehicle speed detected by the vehicle speed sensor 41 (or wheel speed sensor), and the accelerator pedal depression amount detected by the accelerator pedal sensor 11, and determines whether or not the conditions for intervening in the erroneous start prevention control (engine torque suppression control) are met based on these.

[0017] In other words, when the vehicle speed detected by the vehicle speed sensor 41 is in a low speed range below a predetermined value or the vehicle is stopped, and the obstacle detection means 31 detects an obstacle within a predetermined distance in the direction of travel, and the accelerator pedal sensor 11 detects an accelerator depression amount greater than a predetermined value, it is determined that the conditions for intervening in the false start suppression control are met.

[0018] When the conditions for intervening in the false start prevention control are met, the engine controller 10 limits the accelerator opening based on the torque suppression command from the false start prevention control unit 30, and suppresses the engine torque, regardless of the accelerator pedal depression amount (torque request).

[0019] In addition to the above, the false start prevention control unit 30 also acquires information such as the acceleration detected by the acceleration sensor 42, the vehicle inclination (road surface inclination) detected by the inclination sensor 43, and the selected gear stage of the transmission control unit (not shown).

[0020] For example, if the inclination sensor 43 detects an inclination, the amount of torque reduction to be suppressed is adjusted according to the direction and degree of the inclination. Also, if the acceleration sensor 42 detects acceleration in the reverse direction even though the selected gear is not reverse while the false start prevention control is in operation, it is determined that the vehicle is skidding, and the amount of torque reduction is adjusted to be smaller, so that the creep torque that prevents the vehicle from skidding is maintained. Note that the inclination sensor 43 can be an inclination sensor, an acceleration sensor, a multi-axis inertia sensor, or the like that detects the inclination of the refrigerated / freezer vehicle 1 in the fore-and-aft direction based on the acceleration of gravity.

[0021] As shown in FIG. 1, the obstacle detection means 31 preferably includes a front obstacle sensor 31a that detects obstacles in front of the vehicle and a rear obstacle sensor 31b that detects obstacles behind the vehicle, and is configured to selectively execute erroneous start suppression control in the forward direction and erroneous start suppression control in the reverse direction according to selected gear information from the transmission control unit.

[0022] As the obstacle detection means 31, various sensors capable of acquiring information on the presence or absence of an obstacle and the distance to the obstacle, such as an ultrasonic sensor or millimeter wave radar, can be suitably used, and a stereo camera or LIDAR can also be used or used in combination.

[0023] The false start prevention control unit 30 is composed of a computer (ECU) consisting of a ROM that stores control programs and setting data for executing the above-mentioned control, a RAM that temporarily stores the results of calculation processing, a CPU that performs calculation processing, a communication I / F, etc., and is able to obtain each detection information via the in-vehicle network.

[0024] Incidentally, in the refrigerated / freezer vehicle 1, in situations where cooling capacity is required, such as due to the set temperature of the refrigerator / freezer 2, or immediately after the door is opened or closed or the cooling switch is turned on, the compressor 22 needs to be driven at high speed, and this increases the torque request value from the refrigerator / freezer control unit 20 to the engine controller 10. Therefore, if false start suppression control (engine torque suppression control) is executed when the engine torque is reduced due to the load on the compressor 22, there is a risk that the torque reduction amount of the engine 12 will become too large.

[0025] (Improved false start suppression control) Therefore, the erroneous start prevention control unit 30 of the refrigerated / freezer vehicle 1 according to the present invention is configured to set a constant or zero torque request value to be allocated to the compressor 22 of the refrigerated / freezer 1 in the engine controller 10 when the conditions for intervening in the erroneous start prevention control are met. Below, several embodiments of the improved erroneous start prevention control will be described with reference to the drawings.

[0026] (First embodiment) 3 is a flowchart showing the erroneous start prevention control according to the first embodiment. The erroneous start prevention control is initiated when the engine 12 of the refrigerated / freezer vehicle 1 is running (step 100), and the erroneous start prevention control unit 30 monitors the vehicle speed detected by the vehicle speed sensor 41 (or wheel speed sensor), the distance to an obstacle detected by the obstacle detection means 31, and the amount of depression of the accelerator pedal detected by the accelerator pedal sensor 11 (step 101).

[0027] When the vehicle speed is in a low speed range below a predetermined value or when the vehicle is stopped, and an obstacle is detected within a predetermined distance in the direction of travel, and an accelerator depression amount greater than a predetermined value is detected, and it is determined that the condition for intervening in the false start prevention control is met (step 101; YES), if the compressor 22 of the refrigerator / freezer 2 is stopped (cooling off) (step 102; NO), operation of the compressor 22 is prohibited until the condition for terminating the false start prevention control is met (step 103).

[0028] On the other hand, when it is determined that the conditions for intervention of the false start suppression control are met, if the compressor 22 of the refrigerator / freezer 2 is operating (cooling on) (step 102; YES), the refrigerator / freezer control unit 20 disconnects the electromagnetic clutch of the compressor 22 to stop the compressor 22 (cooling off) (step 105).

[0029] At the same time, the engine controller 10 sets the torque request value to be assigned to the compressor 22 to zero, and then determines the torque reduction amount of the engine 12 by referring to the inclination detected by the inclination sensor 43 as necessary, and limits the accelerator opening to suppress the engine torque.

[0030] For example, when the false start prevention control unit 30 determines that the condition for intervention of the false start prevention control is met, the false start prevention control operation flag is turned on and the engine controller 10 sets the torque request value assigned to the compressor 22 to zero, causing the refrigerator / freezer control unit 20 to stop the compressor 22, or when the false start prevention control operation flag is turned on, the refrigerator / freezer control unit 20 stops the compressor 22 and simultaneously sets the torque request to the engine controller 10 to zero.

[0031] The false start prevention control unit 30 continues to monitor the conditions for intervention of the false start prevention control even while the engine torque suppression control (false start prevention control) is being operated by the engine controller 10, and while the false start prevention control operation flag is on, the torque request value allocated to the compressor 22 is maintained at zero, and the refrigerator / freezer control unit 20 maintains the compressor 22 in a stopped state (cooling off).

[0032] Thereafter, if the condition for intervening in the false start prevention control is no longer met, for example, when the driver releases the accelerator pedal, and the condition for terminating the false start prevention control is met (step 107; YES), the false start prevention control activation flag is turned off, and the refrigerator / freezer control unit 20 connects the electromagnetic clutch to activate the compressor 22 (cooling on) (step 109).

[0033] By executing the above-described control, the engine controller 10 can determine an appropriate torque reduction amount based on the state of the vehicle when there is no load on the compressor 22, regardless of the operating state of the refrigerator / freezer 2 when the false start prevention control is activated, and accurate false start prevention control can be executed. During this time, the operation of the refrigerator / freezer 2 is stopped, but if the stop is for a short period of time, there is no significant impact on the cooling state. This has the advantage that false start prevention control, which occurs infrequently but has a high priority, can be executed at low cost and is suited to actual conditions.

[0034] Note that, after the conditions for intervening in the erroneous start prevention control are met and the electromagnetic clutch of the compressor 22 is disengaged, if the conditions for terminating the erroneous start prevention control are met (step 107; YES), the electromagnetic clutch of the compressor 22 may be connected after a predetermined time (second predetermined time; about one minute) has elapsed. This configuration has the advantage of reducing the burden on the compressor and extending its lifespan.

[0035] (Second embodiment) FIG. 4 is a flowchart showing the erroneous start suppression control according to the second embodiment. The basic flow is the same as that of the first embodiment, so only the changes will be explained below.

[0036] In the first embodiment described above, if the compressor 22 of the refrigerator / freezer 2 is operating (cooling on) when the intervention condition for the false start prevention control is met (step 102; YES), the compressor 22 is immediately stopped (cooling off). However, in the second embodiment shown in Figure 4, after the intervention condition for the false start prevention control is met and a predetermined time (first predetermined time) has elapsed (step 104; YES), the engine controller 10 sets the torque request value allocated to the compressor 22 to zero, and the refrigerator / freezer control unit 20 disconnects the electromagnetic clutch of the compressor 22 to stop the compressor 22 (cooling off) (step 105).

[0037] In this case, when the conditions for intervening in the false start suppression control are met, the engine controller 10 determines the amount of torque reduction while maintaining the compressor 22 in an operating state (thus taking into consideration the torque demand (load) of the compressor 22) and executes the engine torque suppression control, so that the amount of torque reduction is small until a predetermined time has elapsed.

[0038] Then, at a timing (e.g., 0.5 to 2 seconds) that will prevent the vehicle from colliding with an obstacle (or from going over a wheel stopper), the torque requirement value allocated to compressor 22 is set to zero, and the engine torque is further suppressed, thereby transitioning to more powerful false start suppression control.

[0039] By performing this control, if the condition for ending the erroneous start suppression control is met, such as the driver releasing the accelerator before the predetermined time has elapsed (step 108; YES), the erroneous start suppression control ends at that point, and the refrigerator / freezer 2 (compressor 22) is maintained in an operating state (cooling on).This has the advantage of being able to perform practical erroneous start suppression while reducing the impact on the cooling performance of the refrigerator / freezer 2.

[0040] (Third embodiment) FIG. 5 is a flowchart showing the erroneous start suppression control according to the third embodiment. The basic flow is the same as that of the first embodiment, so only the changes will be explained below.

[0041] In the first embodiment described above, if the compressor 22 of the refrigerator / freezer 2 is operating (cooling on) when the condition for intervention of the false start suppression control is met (step 102; YES), the compressor 22 is stopped (cooling off). However, in the third embodiment shown in FIG. 5, the electromagnetic clutch of the compressor 22 is maintained connected, and the engine controller 10 keeps the torque request value allocated to the compressor 22 constant instead of zero, and transitions the refrigerator / freezer 2 to constant output operation (step 106).

[0042] In this case, when the conditions for intervening in the false start suppression control are met, the engine controller 10 determines the amount of torque reduction while maintaining the compressor 22 in an operating state (thus taking into account the torque demand (load) of the compressor 22) and executes the engine torque suppression control, so the amount of torque reduction is smaller than when the compressor 22 is stopped.

[0043] However, even if there is a cooling request thereafter due to a temperature change in the refrigerator / freezer 2 during the false start prevention control, the torque request value allocated to the compressor 22 is maintained constant, so torque fluctuations due to the cooling request are avoided and stable false start prevention control can be performed.

[0044] Furthermore, while the false start prevention control is operating, the compressor 22 is maintained at a low rotation speed, but the operation of the compressor 22 continues, which has the advantage that the cooling state of the refrigerator / freezer 2 is maintained well compared to when the compressor 22 is stopped.

[0045] Thereafter, if the condition for terminating the false start prevention control is met, such as when the driver releases the accelerator (step 107; YES), the false start prevention control activation flag is turned off, and the engine controller 10 transitions to normal operation in which it allocates a torque request value to the compressor 22 according to the torque request of the refrigerator / freezer control unit 20 (step 109).

[0046] (Fourth embodiment) FIG. 6 is a flowchart showing the erroneous start suppression control according to the fourth embodiment. The basic flow is the same as that of the second embodiment shown in FIG. 4, so only the changes will be explained below.

[0047] In the false start prevention control of the fourth embodiment, if the compressor 22 of the refrigerator / freezer 2 is operating (cooling on) when the condition for intervening in the false start prevention control is met (step 102; YES), the control is switched depending on the distance to the obstacle detected by the obstacle detection means 31.

[0048] That is, if the distance to the obstacle is equal to or greater than a predetermined value (step 104; YES), after the condition for intervention of the false start suppression control is met, timing of a predetermined time (first predetermined time) begins, and after the predetermined time has elapsed (step 105; YES), the torque request value assigned to the compressor 22 is set to zero and the compressor 22 is stopped (cooling off), or the torque request value assigned to the compressor 22 is kept constant and a transition to constant output operation is made (step 106).

[0049] In this case, when the conditions for intervening in the false start suppression control are met, the engine controller 10 determines the amount of torque reduction while maintaining the compressor 22 in an operating state (taking into account the torque demand (load) of the compressor 22) and executes the engine torque suppression control, so that the amount of torque reduction is small until a predetermined time has elapsed.

[0050] Then, at a timing (e.g., 0.5 to 2 seconds) that will prevent the vehicle from colliding with an obstacle (or from going over a wheel stopper), the torque request value allocated to compressor 22 is set to zero, the engine torque is further suppressed, and a transition is made to more powerful false start suppression control.

[0051] Also, if the condition for terminating the false start suppression control is met, such as the driver releasing the accelerator before a predetermined time has elapsed (step 108; YES), the false start suppression control ends and the refrigerator / freezer 2 (compressor 22) is maintained in an operating state.

[0052] On the other hand, if the distance to the obstacle is less than a predetermined value (step 104; NO), after the conditions for intervention of the false start suppression control are met, the torque request value assigned to the compressor 22 is immediately set to zero and the compressor 22 is stopped (cooling off), or the torque request value assigned to the compressor 22 is kept constant and a transition to constant output operation is made (step 106).

[0053] As described above, by switching the control of refrigerator / freezer 2 depending on the distance to the obstacle, it is possible to prevent collisions with obstacles due to erroneous starts while reducing the impact on the cooling performance of refrigerator / freezer 2.

[0054] Furthermore, by setting the torque during the false start prevention control operation when the freezer is operating for the above-mentioned predetermined time (first predetermined time) high enough to prevent slippage even when the freezer is operating, it is possible to prevent the compressor 22 of the refrigerator / freezer 2 from being stopped unnecessarily or to prevent a decrease in cooling performance.

[0055] The predetermined time (first predetermined time) may be configured to be dynamically set according to the distance to the obstacle detected by the obstacle detection means 31. In other words, the predetermined time (first predetermined time) is set to be longer the greater the distance to the obstacle, and set to be shorter the shorter the distance to the obstacle, which is advantageous in achieving both erroneous start suppression performance and cooling performance.

[0056] Although several embodiments of the present invention have been described above, it should be noted that the present invention is not limited to the above-described embodiments, and various modifications and variations are possible based on the technical concept of the present invention. [Explanation of symbols]

[0057] 1 Refrigerated / freezer vehicle 2 Refrigerator / Freezer 10 Engine Controller 11 Accelerator pedal sensor 12 Engine 20 Refrigerator / freezer control unit 21 Control section 22 Compressor 23 Capacitor 24 Receiver dryer 25 Evaporator 30 False start prevention control unit 31 Obstacle detection sensor 41 Vehicle speed sensor 42 Acceleration sensor 43 Tilt sensor

Claims

1. an engine control unit that controls the engine in response to a torque request; a refrigerator / freezer that performs cooling using a compressor operated by the output of the engine; A refrigerated / freezer vehicle equipped with The vehicle has an engine torque suppression function that suppresses engine torque when the accelerator pedal is operated while an obstacle is detected within a predetermined distance in the direction of travel at a predetermined low vehicle speed or less, A refrigerated / freezer vehicle characterized in that, when the engine torque suppression function is activated, a torque request value allocated to the compressor is kept constant.

2. 2. The refrigerated / freezer vehicle according to claim 1, wherein the accelerator pedal is operated while an obstacle is detected within a predetermined distance in the direction of travel at a vehicle speed below a predetermined low vehicle speed, the condition for intervening the engine torque suppression function is met, and after a first predetermined time has elapsed, the torque request value allocated to the compressor is made constant.

3. 3. The refrigerated / freezer vehicle according to claim 2, wherein the first predetermined time is dynamically set according to the distance to the obstacle, and is set to be longer as the distance to the obstacle increases.

4. an engine control unit that controls the engine in response to a torque request; a refrigerator / freezer that performs cooling using a compressor operated by the output of the engine; A refrigerated / freezer vehicle equipped with The vehicle has an engine torque suppression function that suppresses engine torque when the accelerator pedal is operated while an obstacle is detected within a predetermined distance in the direction of travel at a predetermined low vehicle speed or less, a refrigerated / freezer vehicle configured to set a torque request value allocated to the compressor to a constant value or to zero after a condition for intervening the engine torque suppression function is met and a first predetermined time has elapsed, the first predetermined time being dynamically set according to the distance to the obstacle, and being set to a longer value as the distance to the obstacle increases.

5. 5. The refrigerated / freezer vehicle according to claim 4, wherein the compressor is stopped when the torque request value assigned to the compressor is set to zero.

6. 6. The refrigerated / freezer vehicle according to claim 5, wherein the compressor is configured to be operated after a second predetermined time has elapsed if a termination condition for the engine torque suppression function is met after the compressor is stopped.

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