JP2011085446A - Engine cooling liquid control unit and testing system on engine stand - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To control temperature of a cooling liquid in an engine to desired temperature faster than conventionally, for an engine cooling liquid control unit which sends out a cooling liquid to an engine to be tested, by controlling the temperature of the cooling liquid and a testing system on an engine stand for testing engine on the stand. <P>SOLUTION: Temperature operation value is obtained, by acquiring a first temperature measurement value outputted from a first temperature sensor for measuring temperature of an engine exit part of a cooling liquid within a cooling liquid circulation path and a second temperature measurement value, outputted from a second temperature sensor for measuring temperature of an exit part of the engine cooling liquid control unit of a cooling liquid within the cooling liquid circulation path and then by adding an average deviation of the first temperature measurement value from the second temperature value to the second temperature measurement value. The flow rate water for cooling is controlled so as to control the temperature operation value to be identical to the target temperature. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to an engine coolant control apparatus that controls the temperature of coolant and sends it to an engine to be tested, and an engine bench test system that performs an engine bench test.

  In recent years, from the viewpoint of the global environment, there is an increasing need for highly accurate measurement of fuel efficiency and performance in a shorter time in an engine bench test system.

  Here, the engine stand test refers to a test that is performed while installing the engine to be tested in a room and using various facilities installed around the engine.

  As one of the general test methods for engine bench tests, a dynamometer (here, a power device capable of generating and controlling power as well as measurement and measurement functions) is connected to the engine under test, and the dynamometer There is a method of measuring the engine output torque, fuel consumption, temperature and pressure of each part at that time by controlling the rotation speed of the engine and the throttle opening of the engine. In conducting this test, a more accurate test is performed by controlling the temperature and pressure of the fuel supplied to the engine and the temperature and pressure of the engine coolant. Even in the bench test, in recent years, there is a strong demand for a test equivalent to an actual vehicle, and the control conditions for the temperature and pressure of the fuel and the coolant are becoming more severe. In particular, the temperature control of the cooling liquid is slow in response, so it takes a long time to reach the target temperature, which is a major obstacle to efficient high-accuracy testing.

  Patent Document 1 has a proposal for engine lubricant temperature control.

JP-A-6-117212

  In view of the above circumstances, the present invention is an engine coolant control device capable of controlling the engine coolant temperature to a desired temperature faster than before, and a test in a short time using the engine coolant control device. It is an object of the present invention to provide an engine bench test system capable of performing the above.

The engine coolant control apparatus of the present invention that achieves the above object shares a part of a coolant circulation path that sends coolant to the engine under test and sends the coolant sent from the engine back into the engine, and circulates the coolant. An engine coolant control device that controls the temperature of the coolant in the road and sends the coolant toward the engine,
A heat exchanger disposed on the coolant circulation path for cooling the coolant in the coolant circulation path with the second coolant;
A valve opening degree control unit that controls the opening degree of the flow rate adjustment valve that adjusts the flow rate of the second coolant fed into the heat exchanger;
The valve opening control unit is
This engine coolant control of the first temperature measurement value measured by the first temperature sensor that measures the temperature of the engine outlet portion of the coolant in the coolant circulation path and the coolant in the coolant circulation path The second temperature measurement value measured by the second temperature sensor that measures the temperature of the apparatus outlet portion is acquired, and the second temperature measurement value of the first temperature measurement value is obtained as the second temperature measurement value. A temperature calculator that calculates a temperature calculation value by adding an average deviation from
Flow rate for controlling the temperature calculation value to the same value as the target temperature by receiving the target temperature of the coolant outlet in the coolant circulation path and the temperature calculation value obtained by the temperature calculator A PID controller that outputs a first valve opening control value representing the opening of the regulating valve;
And a valve opening controller that controls the opening of the flow rate adjustment valve to an opening corresponding to the first valve opening control value output from the PID controller.

  When testing the engine, it is necessary to control the temperature of the coolant at the engine outlet to a target temperature in order to cool the engine appropriately.

  Here, the length of the coolant circulation path is 10 m to 15 m per circuit in many cases because of the layout of the laboratory, and is the length from the heat exchanger in the engine coolant control device to the engine outlet. Even if it is about half as long, even if the coolant temperature at the engine outlet is measured and the temperature of the coolant is controlled by the heat exchanger based on the measured temperature, the control is reflected in the coolant temperature at the engine outlet. Takes a long time and poor responsiveness. In order to improve this responsiveness, it is necessary to shorten the coolant circulation path or to feed the coolant at a high speed.

  The engine coolant control device of the present invention has a second temperature that is a measured value of the coolant temperature at the outlet of the engine coolant controller, in addition to a first temperature value that is a measured value of the coolant temperature at the engine outlet. The measured value is also obtained, the above temperature calculated value is obtained with a temperature calculator, and the temperature calculated value is controlled so as to become the target temperature. Conditions such as the length of the coolant circulation path and the coolant flow rate Is the same as the conventional case, the control response of the temperature of the coolant is improved.

Here, in the engine coolant control apparatus of the present invention, the correspondence relationship between the temperature of the engine outlet portion of the coolant in the coolant circulation path, the horsepower of the engine, and the opening degree of the flow control valve is described in advance. The stored map is stored, the target temperature and the measured horsepower of the engine are input, and the temperature of the engine outlet portion of the coolant in the coolant circulation path is matched with the target temperature by referring to the map. A map calculator for outputting a second valve opening control value representing the opening of the flow regulating valve for
An adder that adds the first valve opening control value output from the PID controller and the second valve opening control value output from the map calculator to generate a third valve opening control value; Further comprising
The valve opening controller preferably controls the flow rate adjustment valve to an opening corresponding to the third valve opening control value generated by the adder.

  Thus, if the map calculator is provided and the opening degree of the flow control valve is controlled based on both the output from the PID controller and the output from the map calculator, the rotational speed of the dynamometer is changed stepwise. The stability is further improved when the test conditions change drastically, such as when the throttle opening is changed suddenly.

  In the engine coolant control apparatus according to the present invention, the temperature calculator obtains an average calculation time corresponding to a time from when the coolant in the coolant circulation path is delivered from the heat exchanger until it reaches the engine outlet. The temperature calculation value is obtained by adding the deviation of the first temperature measurement value over the average calculation time from the second movement measurement value to the second temperature measurement value. Preferably there is.

  The temperature control delay time is closely related to the time until the coolant cooled by the heat exchanger reaches the engine outlet, and therefore the coolant is sent from the heat exchanger and then reaches the engine outlet. By setting the average calculation time corresponding to the time until the temperature calculation value can be obtained in accordance with the response speed of the system, temperature control with higher accuracy is possible.

  Furthermore, the engine coolant control apparatus of the present invention preferably further includes a pump that is disposed on the coolant circulation path and circulates the coolant in the coolant circulation path.

  By providing this pump, the pressure of the coolant at the engine inlet and the engine outlet can be controlled with higher accuracy.

  Furthermore, in the engine coolant control apparatus of the present invention, it is preferable that the heat exchanger cools the coolant in the coolant circulator using industrial water as the second coolant.

  As the second cooling liquid, a cooling liquid to which a solute for cooling is added may be employed, but industrial water may be used as it is.

In addition, the engine bench test system of the present invention,
An engine coolant control device of the present invention;
A dynamometer connected to the output shaft of the engine;
A fuel control measuring device for controlling the temperature and pressure of the fuel to supply the fuel to the engine and measuring the fuel consumption;
And a throttle actuator for controlling the throttle opening of the engine.

  Here, as described above, a power device capable of generating and controlling power as well as measurement and measurement functions is referred to as a dynamometer.

  Since the engine bench test system of the present invention employs the engine coolant control apparatus of the present invention, the low responsiveness of the coolant temperature, which has been an obstacle in the past, is eliminated, and the accuracy and efficiency are high. Engine stand test can be performed.

  According to the present invention described above, the engine coolant can be controlled to a desired temperature at a higher speed than in the prior art.

It is a block diagram showing one embodiment of an engine stand test system of the present invention. It is the block diagram which showed the coolant circulation path among the engine stand top test systems shown in FIG. It is a block diagram which shows the coolant temperature control circuit in this embodiment. It is calculation method explanatory drawing of average calculation time (sec). It is a flowchart which shows the calculation method of the temperature calculation value in the temperature calculator shown in FIG. It is a figure which shows a coolant temperature control flow. It is the conceptual diagram which showed the temperature change of the cooling fluid when the existing control method was employ | adopted. It is the conceptual diagram which showed the temperature change of the cooling fluid in this embodiment. It is the figure which showed the fluctuation | variation of the temperature T1 when changing test conditions in steps.

  Embodiments of the present invention will be described below.

  FIG. 1 is a block diagram showing an embodiment of the engine bench test system of the present invention.

  This FIG. 1 shows in a test chamber 100 an engine 10 to be tested, a dynamometer 20, a throttle actuator 30, a fuel control measuring device 40, an engine coolant control device 50, an on-site relay box 60, a cooling device. A coolant pipe 70 forming a liquid circulation path and an industrial water pipe 80 forming an industrial water path are shown. Here, an operation panel 90 is provided outside the test chamber 100. An exhaust pipe 11 extends from the engine 10 and is exhausted out of the building by an exhaust fan (not shown) which is a building facility.

  Here, the dynamometer 20 is coupled to the output shaft 15 of the engine 10, and the rotational speed and torque are controlled by controlling the dynamometer current.

  The throttle actuator 30 controls the throttle opening of the engine 10.

  The fuel control measuring device 40 controls the temperature and pressure of the fuel supplied to the engine 10 and supplies it to the engine 10. The fuel control measuring device 40 measures fuel consumption.

  The engine coolant control device 50 is an example of the engine coolant control device of the present invention, and circulates the coolant by controlling the temperature and pressure of the coolant. The temperature control of the coolant is performed by heat exchange with industrial water flowing in the industrial water pipe 80.

  The engine 10 is provided with a temperature sensor, a pressure sensor, and the like in each part, and the on-site relay box 60 measures the temperature and pressure of each part of the engine by those sensors. The field relay box 60 is also in charge of electrical control of the ignition and starter. The operation panel 90 includes an operation unit for performing an engine bench test by manual operation and automatic operation, and a CPU that performs control, measurement, and management. Note that the control panel 90 has signal lines for control and measurement extending to each part, but is omitted from the drawing to avoid complication.

  FIG. 2 is a block diagram showing a coolant circulation path in the engine bench test system shown in FIG.

  The coolant circulation path includes a flow path in the engine 10, a flow path in the engine coolant control apparatus 50, and a coolant pipe 70 that connects the two flow paths. On this coolant circulation path, a circulation pump 12 in the engine 10, a circulation pump 51 in the engine coolant control device 50, and a heat exchanger 52 in the engine coolant control device 50 are arranged. The coolant generated by the operation of the engine 10 is, by the circulation pump 12 in the engine 10, the outlet of the engine 10 → the inlet of the engine coolant control device 50 → the circulation pump 51 in the engine coolant control device 50 → the heat exchanger 52. → Circulate with the outlet of the engine coolant control device 50 → the inlet of the engine 10. The circulation distance ranges from about 10 m to 15 m per round. When the engine 10 is operated, the circulation pump 12 in the engine 10 coupled to the output shaft of the engine 10 rotates, and the coolant circulates. Therefore, the flow rate of the coolant (liter / min) is substantially proportional to the rotational speed of the engine 10. Here, a circulation pump 51 is also provided in the engine coolant control apparatus 50. The circulation pump 51 controls the coolant pressure P1 at the outlet of the engine 10 or the coolant pressure P2 at the inlet to an arbitrary pressure according to the test contents. Alternatively, the differential pressure between the outlet pressure P1 and the inlet pressure P2 is controlled to be a specified value, usually equivalent to an actual vehicle.

  An industrial water flow path is also formed in the heat exchanger 52 in the engine coolant control device 50, and the coolant is cooled with the industrial water while passing through the heat exchanger 52 and directed to the engine 10 again. Sent out. An industrial water flow rate adjusting valve 81 is provided in the middle of the industrial water pipe 80 forming the industrial water flow path. The flow rate adjustment valve 81 has its opening degree adjusted by a control motor 82. The heat exchanger 52 exhibits a cooling capacity corresponding to the flow rate of the industrial water, and the cooling liquid is cooled according to the flow rate of the industrial water.

  Here, the amount of industrial water flowing through the heat exchanger 52 is adjusted so that the coolant T1 at the outlet of the engine 10 becomes the set temperature. At this time, when the rotational speed of the engine 10 is low, the flow rate of the coolant is low, and as a result, it takes a long time for the coolant exiting the engine coolant controller 50 to reach the outlet of the engine 10.

  Conventionally, generally, PID control is performed so that a temperature T1 near the engine outlet is measured and the temperature T1 becomes a set temperature. In this case, it is necessary to consider a large time delay until the coolant cooled by the heat exchanger 52 reaches the outlet of the engine 10, and it is necessary to limit the control slowly. As a result, it takes a long time for the temperature T1 at the outlet of the engine 10 to reach the target temperature, and a highly accurate test and measurement cannot be performed efficiently.

  Therefore, here, while monitoring the temperature T1 of the coolant at the outlet of the engine 10, the temperature T2 of the coolant at the outlet of the engine coolant controller 50 is also monitored. A temperature calculation value is obtained by adding a deviation from T2, and the temperature calculation value is a target of PID control. As a result, faster PID control is possible, the time required for the temperature T1 at the outlet of the engine 10 to converge to the target temperature is shortened, and highly accurate testing and measurement can be performed efficiently. Furthermore, if the map described with reference to FIG. 3 is provided, temperature overshoot during transient operation can be suppressed.

  FIG. 3 is a block diagram showing a coolant temperature control circuit in the present embodiment.

  Here, a PID controller 510, a temperature calculator 520, a map calculator 530, a switch 540, an adder 550, and a valve opening controller 560 are shown.

  3 also shows the engine 10 shown in FIG. 2, the circulation pump 51 in the engine coolant control apparatus, the heat exchanger 52, the coolant pipe 70, the industrial water pipe 80, the flow control valve 81, A motor 82 for controlling the valve opening degree of the flow rate adjusting valve 81 is also shown.

  Further, here, a temperature sensor 521 for measuring the temperature T1 at the engine outlet of the coolant flowing in the coolant circulation path formed by the coolant pipe 70 or the like is provided. The measured temperature value T1 of the coolant at the engine outlet output from the temperature sensor 521 is input to the temperature calculator 520. Similarly, a temperature sensor 522 for measuring the temperature of the coolant at the outlet of the engine coolant control device 50 (see FIG. 2) is disposed, and the engine coolant control output from the temperature sensor 522 is disposed. The temperature measurement value T2 of the coolant at the outlet of the apparatus 50 is also input to the temperature calculator 520. A speed sensor 531 for measuring the rotational speed of the output shaft of the engine 10 and a dynamometer 20 for measuring the torque of the output shaft of the engine are arranged.

  The rotational speed and torque of the engine output shaft measured by the speed sensor 531 and the dynamometer 20 are multiplied by a multiplier 533 and converted into a horsepower measurement value. The horsepower measurement value is input to the map calculator 530.

  The map calculator 530 stores a map 530 a representing the correspondence relationship between the coolant temperature T1 at the engine outlet, the horsepower output from the engine 10, and the opening degree of the industrial water flow rate adjustment valve 81. . This map 530a is created by creating a stable operating state under various conditions and acquiring the temperature T1, horsepower, and valve opening. When the engine bench test is actually performed, the target temperature (Tset) instead of the temperature T1 and the temporary horsepower measurement value at that time are input to the map calculator 530, and the flow rate adjustment is performed by referring to the map 530a. The opening of the valve 81 (here, this valve opening is referred to as “predicted valve opening” in order to distinguish it from the valve opening output from the PID controller 510). The predicted valve opening degree output from the map calculator 530 passes through the switch 540, and the valve opening degree output from the PID controller 510 (to be described later) by the adder 550 (here, this is referred to as "PID control valve opening degree"). The added valve opening is input to the valve opening controller 560. The valve opening controller 560 sends a signal to the motor 82 to control the flow rate adjustment valve 81 to an opening corresponding to the input valve opening.

  As described above, the temperature calculator 520 receives the calculated coolant temperature T1 at the engine outlet and the measured temperature T2 at the device outlet measured by the two temperature sensors 521 and 522. Based on this, a temperature calculation value (herein, this temperature calculation value is referred to as “T1 FB (feedback)”) is obtained.

T1 F.E. B. (° C.) = T2 + Σ (T1-T2) / N (1)
Here, N is an average calculation time (sec) obtained as follows.

  However, N is specifically a discrete number obtained by dividing the average calculation time corresponding to the average calculation time by the calculation cycle Δt.

  FIG. 4 is an explanatory diagram of a method for calculating the average calculation time (sec).

  FIG. 4 is a diagram showing the length D (m) of the coolant flow path from the heat exchanger 52 in the engine coolant control apparatus 50 (see FIG. 2) to the engine outlet. Since the temperature sensor 522 at the apparatus outlet is disposed adjacent to the heat exchanger, this distance D (m) is the same as the distance from the temperature sensor 522 to the temperature sensor 521.

  The average calculation time (sec) is calculated as follows.

The flow rate R of the coolant is
R = A / πB ² (2)
Here, A is the coolant flow rate (m ³ / sec)
B is the inner diameter of the coolant pipe (m)
R is the coolant flow velocity (m / sec)
It is. Since the coolant flow rate A is proportional to the engine speed, it can be obtained from the engine speed.

The average calculation time N (sec) is
N = D / R (3)
Here, D is the distance (m) shown in FIG.
R is the flow rate of the coolant (m / sec) determined by equation (2)
It is.

  Here, as described above, the average calculation time N is calculated from the coolant flow rate, the pipe diameter, and the pipe length obtained from the engine rotation speed, and is used for the calculation by the equation (1). By doing so, the temperature calculation value T1 F.F. matched to the response speed of this system. B. (° C.) is calculated.

  FIG. 5 shows the temperature calculation value T1 F.F. in the temperature calculator 520 shown in FIG. B. It is a flow chart which shows how to obtain.

When the calculation of the temperature is started, at the first time, the temperature deviation T5 is expressed by the expression T5 = T1-T2 (4)
(Step S11). Here, T1 and T2 are an engine outlet temperature measurement value and a device outlet temperature measurement value, respectively.

Next, measurement of elapsed time C from the calculation time of the first temperature calculation value T3 is started (step S12), and temperature deviation T3 = T1-T2 (5) again.
Is calculated (step S13), and the total T4 (initial value is T4 = 0) during the average calculation time N (sec) of the temperature deviation T3 is expressed by the equation T4 = T3 + T4 (6)
(Step S14). This equation (6) means that a value obtained by adding the temperature deviation T3 calculated this time to the previous total sum T4 is set as a new total sum T4.

Next, it is determined whether or not the elapsed time C has reached the average calculation time N (sec) (step S15). When the elapsed time C reaches the moving average time N (sec), the temperature deviation average value T5 is expressed by the equation T5 = T4 / N (7)
(Step S16), the elapsed time C is reset to C = 0 (step S17), and the temperature calculation value T1 F.F. B. Is represented by the formula T1 F. B. = T2 + T5 (8)
Is output to the PID controller 510 shown in FIG. 3 (step S18). If it is determined in step S15 that the elapsed time C has not reached the average calculation time N (sec), the previously calculated temperature calculation value T1 F.F. B. Will continue to be output.

  As described above, in the present embodiment, the temperature calculation value T1 F.F. according to the flow rate of the coolant described with reference to FIG. 4, that is, according to the current responsiveness of the system at that time. B. The update cycle of is changed. Here, the temperature calculation value calculation cycle itself is changed. However, the temperature calculation value calculation cycle may be adjusted in accordance with one sampling cycle of the temperatures T1 and T2.

  FIG. 6 is a diagram showing a coolant temperature control flow.

  Here, it is first determined whether or not a valid map 530a exists in the map calculator 530 (step S21). When the map 530a exists, the map calculator 530 obtains the predicted valve opening (step S21). S22). Further, the temperature calculator 520 calculates the temperature calculation value (step S24), and the PID controller 510 calculates the PID control valve opening from the temperature calculation value and the target temperature Tset (step S24). . The predicted valve opening obtained in step S22 is input to the adder 550 through the switch 540, and the PID control valve opening calculated in step S24 is also input to the adder 550. Is added. The adder 550 outputs the valve opening composed of the added value as a command value to the valve opening controller 560 (step S25). The valve opening controller 560 outputs a control current to the control motor 82 so that the opening of the flow rate adjustment valve 81 matches the valve opening as the command value.

  When it is determined in step S21 in FIG. 6 that there is no valid map 530a in the map calculator 530, the switch 540 is opened, and only the PID control valve opening from the PID controller 510 is input to the adder 550. Then, a command value including the PID control valve opening is output from the adder 550 to the valve opening controller 560. The valve opening controller 560 sends a control current to the control motor 82 so that the flow rate adjustment valve 81 has an opening corresponding to the PID control valve opening.

  Here, when the map calculator 530 is used, the rough value of the valve opening is determined by the predicted valve opening, and the PID controller 510 is a small value that only corrects the error from the rough valve opening. The PID control valve opening is output. On the other hand, when the map calculator 530 is not used, the PID control valve opening indicating the full width of the valve opening is output from the PID controller 510.

  In the PID controller 510, the temperature calculation value T1 F.F. B. Therefore, when the switch 540 is turned on, the PID control valve opening only automatically corrects the predicted valve opening obtained by the map calculator 530. When the switch 540 is turned off, it becomes a large value that only controls the opening degree of the flow rate adjusting valve only by the opening degree of the PID control valve including the predicted opening degree of the valve.

  In FIG. 3, the switch 540 is provided, and in FIG. 6, step S <b> 21 is placed, and it has been described that both the case of using the map calculator 530 and the case of not using the map calculator 530 are used. When the map calculator 530 is always used, the switch 540 and step S21 in FIG. 6 are not necessary. Alternatively, only the temperature calculator 520 and the PID controller 510 may be used without using the map calculator 530. In that case, the map calculator 530, the switch 540, and the adder 550 are unnecessary, An output value from the PID controller 510 is input to the valve opening controller 560. At this time, the multiplier 533, the speed sensor 531 and the dynamometer 20 for inputting horsepower to the map calculator 530 are also not necessary for the temperature control of the coolant shown in FIG. However, the rotational speed and torque of the engine 10 are important measurement items, and are necessary for the engine bench test system shown in FIG.

  FIG. 7 is a conceptual diagram showing the temperature change of the coolant when the existing control method is adopted, and FIG. 8 is a conceptual diagram showing the temperature change of the coolant in the present embodiment.

  The existing control method of FIG. 7 is a comparative example compared with the present embodiment. In FIG. 3, the map calculator 530 and the temperature calculator 520 are not present, and the coolant temperature T1 at the engine outlet is directly set to PID. Input to the controller 10, the PID controller 510 obtains a PID control valve opening for making the temperature T1 coincide with the target temperature Tset, and controls the opening of the flow regulating valve 81 based on the PID control valve opening. This refers to the case where the conventional method is adopted.

  In the case of the comparative example shown in FIG. 7, the engine outlet temperature T1 is greatly deviated from the target temperature Tset as compared to the case of the embodiment shown in FIG. In the embodiment shown in FIG. 8, the temperature calculation value T1 F.F. calculated by the temperature calculator 520 without using the map calculator 530 is used. B. Is input to the PID controller 10. The temperature calculator 520 controls the valve opening degree by calculating a temperature calculation value considering both the engine outlet temperature T1 and the apparatus outlet temperature T2 for each average calculation time (see FIG. 4) obtained as described above. As shown in FIG. 8, the variation in the engine outlet temperature T1 is suppressed as compared with the comparative example shown in FIG.

  Table 1 is a diagram showing the operation principle, features, and drawbacks of the “existing control method”, “calculation”, and “calculation + map”. Here, “calculation” refers to the case where the switch 540 in FIG. 3 is opened (when the map calculator 530 is not used), and “calculation + map” refers to the case where the switch 540 is closed (the map calculator 530 is changed). When using together).

  Table 2 is a diagram showing evaluation results of controllability and convergence time of “existing control method”, “calculation”, and “calculation + map” in steady operation and transient operation.

  In the case of the existing control method, the controllability is poor when the flow rate of the cooling liquid is lowered even in steady operation, and the convergence time becomes long. In the case of “calculation”, the controllability increases and the convergence time is short in steady operation even at a low flow rate. Even in transient operation, improvements can be seen compared to the “existing control method”. In the case of “calculation + map”, not only steady operation but also transient operation can be improved further.

  FIG. 9 is a diagram showing fluctuations in the temperature T1 when the test conditions are changed stepwise.

  Here, the dynamometer rotation speed and the engine output shaft torque are changed as shown in the drawing every 20 minutes. As a result, the horsepower also changes as shown. The target temperature Tset of the engine outlet temperature T1 is 80 ° C., and the control target is ± 1 ° C. Both “calculation” and “calculation + map” are stably controlled in a steady state. In the transient state, large fluctuations are seen in the “calculation”, but the “calculation + map” is more stable in the transient response than the “calculation”.

  Here, the cooling liquid in the cooling liquid circulator is cooled using industrial water in the heat exchanger, but the cooling liquid in the cooling liquid circulator is cooled using a cooling liquid other than industrial water. May be adopted.

DESCRIPTION OF SYMBOLS 10 Engine 11 Exhaust pipe 12,51 Circulation pump 15 Output shaft 20 Dynamometer 30 Throttle actuator 40 Fuel control measurement device 50 Engine coolant control device 52 Heat exchanger 60 On-site relay box 70 Coolant piping 80 Industrial water piping 81 Flow rate Adjustment valve 82 Control motor 90 Operation panel 100 Test chamber 510 PID controller 520 Temperature calculator 521, 522 Temperature sensor 530 Map calculator 530a Map 531 Speed sensor 532 Dynamometer 533 Multiplier 540 Switch 550 Adder 560 Valve opening controller

Claims (6)

A part of the coolant circulation path that sends the coolant to the engine under test and sends the coolant sent from the engine back into the engine is shared, and the temperature of the coolant in the coolant circulation path is controlled to An engine coolant control apparatus that sends out coolant toward the engine,
A heat exchanger disposed on the coolant circulation path for cooling the coolant in the coolant circulation path with a second coolant;
A valve opening degree control unit that controls the opening degree of a flow rate adjusting valve that adjusts the flow rate of the second coolant fed into the heat exchanger;
The valve opening control unit is
The engine of the first temperature measurement value measured by a first temperature sensor for measuring the temperature of the engine outlet portion of the coolant in the coolant circulation path and the coolant in the coolant circulation path. A second temperature measurement value measured by a second temperature sensor that measures the temperature of the coolant control device outlet portion, and the second temperature measurement value includes the first temperature measurement value, A temperature calculator for calculating a temperature calculation value by adding an average deviation from the second temperature measurement value;
Receiving the input of the target temperature of the engine outlet portion of the coolant in the coolant circulation path and the temperature calculation value obtained by the temperature calculator, the temperature calculation value is set to the same value as the target temperature. A PID controller that outputs a first valve opening control value representing the opening of the flow regulating valve for controlling;
An engine coolant control apparatus comprising: a valve opening controller that controls the flow rate adjustment valve to an opening degree corresponding to the first valve opening control value output from the PID controller. . A map describing a correspondence relationship between the temperature of the engine outlet portion of the coolant in the coolant circulation path, the horsepower of the engine, and the opening of the flow rate adjusting valve is stored, and the target temperature is stored. And the horsepower measurement value of the engine, and referring to the map, the flow rate adjusting valve for matching the temperature of the engine outlet portion of the coolant in the coolant circulation path with the target temperature. A map calculator for outputting a second valve opening control value representing the opening;
The first valve opening control value output from the PID controller and the second valve opening control value output from the map calculator are added to generate a third valve opening control value. And an adder that
The valve opening controller controls the flow rate adjusting valve to an opening corresponding to the third valve opening control value generated by the adder. Engine coolant control device.   The temperature calculator obtains an average calculation time corresponding to a time from when the coolant in the coolant circulation path is sent out from the heat exchanger until it reaches the outlet of the engine, and the second temperature measurement value Further, the temperature calculation value is obtained by adding a deviation of the first temperature measurement value averaged over the average calculation time from the second movement measurement value. The engine coolant control apparatus according to claim 1 or 2.   The engine coolant control apparatus according to any one of claims 1 to 3, further comprising a pump disposed on the coolant circulation path and circulating the coolant in the coolant circulation path.   5. The heat exchanger according to claim 1, wherein the heat exchanger cools the cooling liquid in the cooling circulator using industrial water as the second cooling liquid. 6. Engine coolant control device. The engine coolant control device according to any one of claims 1 to 5,
A dynamometer coupled to the output shaft of the engine;
A fuel control measuring device for controlling the temperature and pressure of the fuel to supply the fuel to the engine and measuring the fuel consumption;
An engine bench test system comprising a throttle actuator for controlling the throttle opening of the engine.

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