JP2008267270A - Control device for negative pressure generator - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a control device for a vacuum generation device capable of suitably coping with or getting capable of coping with freezing generated in the vacuum generation device. <P>SOLUTION: ECU 40A controls the vacuum generation device 100 comprising an ejector 30 generating vacuum higher than vacuum to be taken out from an intake manifold 14 of an internal combustion engine 50 provided on a vehicle and VSV (vacuum switching valve) 1 making the ejector 30 function and stop function, and is provided with a freezing generation determination means determining existence of freezing according to change of flow rate of intake air flowing in the elector 30 when the VSV 1 is controlled to make the ejector 30 function in a low temperature start warming up process. Concretely, the freezing generation determination means determines whether flow rate of intake air flowing in the ejector 30 suddenly drops or not, and determines generation of freezing when flow rate suddenly drops. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a control device for a negative pressure generating device, and more particularly to a control device for a negative pressure generating device for coping with freezing generated in the negative pressure generating device.

  Conventionally, a negative pressure such as a brake booster is larger than a negative pressure (hereinafter also simply referred to as an intake pipe negative pressure) to be taken out from an intake passage (for example, an intake manifold or a surge tank) of an intake system of an internal combustion engine in a vehicle. An ejector is used to supply the pressure actuator. With regard to this ejector, for example, Patent Document 1 proposes a technique that is considered to be related to the present invention.

JP 2005-188332 A

  By the way, because the ejector has a structure that generates a negative pressure larger than the intake pipe negative pressure due to the venturi effect, the internal flow path corresponding to the portion that generates this negative pressure is narrowed down, and the intake air flows through this internal flow path. When doing so, the temperature drops. For this reason, especially when the ejector functions during the cold start warm-up process of the internal combustion engine where the intake air temperature (or outside air temperature) is low, the water contained in the intake air and the negative pressure generating device including the ejector are accumulated in the line. Condensed water may freeze. On the other hand, such freezing does not necessarily develop into a blockage that completely occludes the line. However, in such a state where freezing has occurred, since the flow path becomes thinner by that amount, there is a possibility that the line may be completely blocked due to contamination and accumulation of foreign matter, and further freezing has occurred. The longer the condition, the greater the risk that the line will be completely blocked.

  Therefore, the present invention has been made in view of the above problems, and an object of the present invention is to provide a control device for a negative pressure generating device that can suitably cope with or be able to cope with freezing generated in the negative pressure generating device. .

  In order to solve the above problems, the present invention provides an ejector that generates a negative pressure larger than the negative pressure to be taken out from an intake passage of an intake system of an internal combustion engine provided in a vehicle, and a state change that causes the ejector to function or stop functioning. A negative pressure generating device for controlling the negative pressure generating device, wherein the state changing means is controlled to function the ejector during a cold start warm-up process. And a freezing occurrence judging means for judging whether or not freezing has occurred according to a change in the flow rate of the intake air flowing through the ejector.

  Here, if freezing occurs in the line of the negative pressure generator when the ejector is functioning, the flow rate of the intake air flowing through the ejector changes. The present invention has been made paying attention to such a point, and according to the present invention, since the occurrence of freezing can be detected by determining whether or not freezing has occurred, it is preferable to cope with freezing that occurs in the negative pressure generator. become able to.

  More specifically, it is preferable that the freezing occurrence determination means perform the determination during cold idling in which the internal combustion engine is in a steady operation state. In this regard, for example, even if the internal combustion engine is not in a steady operation state, it is not always possible to make a determination. In this case, whether or not the change in the flow rate of the intake air flowing through the ejector is due to the occurrence of freezing. As much as it is necessary to specify, it is not easy to determine. When the intake air temperature is sufficiently high, it can be said that there is no possibility of freezing in the negative pressure generating device. Therefore, the freezing occurrence determining means further determines that the intake air temperature is a predetermined value (the intake air temperature is 0 ° C. in the ejector). The determination may be made only when the temperature is lower than a temperature that falls below.

  In the present invention, the freezing occurrence determination means may determine whether or not the flow rate of the intake air flowing through the ejector has suddenly decreased, and may determine that freezing has occurred if the flow rate has rapidly decreased. . Here, when freezing occurs in the line of the negative pressure generating device, specifically, the flow rate of the intake air flowing through the ejector rapidly decreases. For this reason, it is preferable that the freezing occurrence determination means specifically determine whether or not the flow rate of the intake air flowing through the ejector has dropped rapidly, as in the present invention. Whether or not the intake air flow rate has suddenly decreased is determined, for example, by experiments in advance to determine the intake air flow rate that decreases when freezing occurs, and the intake air flow rate is lower than a predetermined value determined based on this. Judgment can be made by whether or not.

  According to the present invention, the freezing occurrence determination means determines whether or not the intake flow rate flowing through the ejector has suddenly decreased when the internal combustion engine is in a cold idling state in a steady operation state. While determining whether or not the control amount related to the ISC control for maintaining has changed by a predetermined value or more, it may be determined that freezing has occurred when the control amount has changed by a predetermined value or more.

  Here, during idling, ISC (Idle Speed Control) control is generally performed to maintain the idling engine speed at the target engine speed. At this time, if the flow rate of the intake air flowing through the ejector sharply decreases due to the occurrence of freezing, the ISC control attempts to increase the flow rate of the intake air in order to maintain the idle rotation speed at the target rotation speed. The control amount related to the amount changes. For this reason, it is preferable to determine whether or not the flow rate of the intake air has sharply decreased based on whether or not the control amount related to ISC control has changed by a predetermined value or more as in the present invention. It should be noted that the control amount related to ISC control is individual feedback related to feedback control (hereinafter simply referred to as F / B) control performed in ISC control and learning control that learns the control amount according to the result of this F / B control. It may be a control amount, or the entire control amount related to ISC control in which these control amounts are collected.

  Further, the present invention comprises an ejector that generates a negative pressure larger than the negative pressure to be taken out from an intake passage of an intake system of an internal combustion engine provided in the vehicle, and a state changing unit that functions or stops the function of the ejector. A negative pressure generator control device for controlling the negative pressure generator, wherein the negative pressure is controlled when the state changing means is controlled to function the ejector during a cold start warm-up process. A cleaning frequency increasing means is provided for increasing the frequency at which the state changing means is controlled so that the ejector functions when the generator is frozen after warming up.

  Here, when the ejector is functioned, the flow rate of the intake air is increased by the amount of intake air flowing through the ejector, which may adversely affect idling and the like. On the other hand, in order to suppress the occurrence of clogging of the negative pressure generator, if the ejector is made to function when fuel injection is not performed in the combustion cycle of the internal combustion engine, negative pressure is generated without adversely affecting idling or the like. Occurrence of clogging of the device can be suppressed. In order to make the ejector function in this way, specifically, it is preferable to make the ejector function according to, for example, fuel cut (hereinafter simply referred to as F / C) control performed in an internal combustion engine. In order to cause the ejector to function as described above, it is preferable to cause the ejector to function when the state changing means is controlled so as to basically stop the function of the ejector (for example, during warming). In order to suppress the occurrence of clogging of the negative pressure generating device in this way, it is not always necessary to cause the ejector to function every time the F / C control is performed. In response to this, after a predetermined function (for example, 10 to 30 minutes) has elapsed, the function is performed when the F / C control is further performed.

  On the other hand, when the ejector is operated during the cold start warm-up process, the negative pressure generator may freeze, but if the engine room is warmed up after the warm-up is completed, it will also freeze. Depending on the temperature of the intake air at this time, the effect of eliminating the freezing at an early stage can be expected. For this reason, when freezing occurs in the negative pressure generator, increasing the frequency with which the ejector functions during the warm-up after warming up is effective in suppressing the occurrence of clogging of the negative pressure generator. It can be said. The present invention has been made paying attention to such a point, and according to the present invention, it can be prevented or suppressed that the line of the negative pressure generating device is completely blocked due to the mixing or accumulation of foreign matters. The effect of eliminating freezing early can also be expected. That is, according to the present invention, it is possible to suitably cope with freezing that occurs in the negative pressure generator.

  In addition, in increasing the frequency, the frequency may be further increased when the temperature of the intake air is higher than a predetermined value (a temperature at which the temperature of the intake air is reduced to 0 ° C. or less by the ejector). Freezing that has occurred more reliably can be resolved early. However, since the freezing caused by the heat from the internal combustion engine is canceled at the same time after the warm-up is completed, it is not always necessary to increase the frequency when the intake air temperature is higher than the predetermined value. I can say that.

  ADVANTAGE OF THE INVENTION According to this invention, the control apparatus of the negative pressure generator which can cope with the freezing which generate | occur | produces with a negative pressure generator suitably, or becomes possible can be provided.

  Hereinafter, the best mode for carrying out the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a diagram schematically showing a control device for a negative pressure generating device according to the present embodiment realized by an ECU (Electronic Control Unit) 40A together with the negative pressure generating device 100. The components shown in FIG. 1 including the internal combustion engine 50 are mounted on a vehicle (not shown). The intake system 10 of the internal combustion engine 50 includes an air cleaner 11, an air flow meter 12, an electric throttle 13, an intake manifold 14, an intake port (not shown) communicating with each cylinder (not shown) of the internal combustion engine 50, and the configuration thereof. For example, intake pipes 15a, 15b and the like are appropriately disposed between the two. The air cleaner 11 is configured to filter the intake air supplied to each cylinder of the internal combustion engine 50, and communicates with the atmosphere via an air duct (not shown). The air flow meter 12 is configured to measure the intake air amount and outputs a signal corresponding to the intake air amount. The air flow meter 12 incorporates an intake air temperature sensor (not shown), and the intake air temperature (hereinafter simply referred to as intake air temperature) is detected by the ECU 40A based on the output of the intake air temperature sensor.

  The electric throttle 13 includes a throttle valve 13a, a throttle body 13b, a valve shaft 13c, and an electric motor 13d. The throttle valve 13a is configured to adjust the amount of intake air supplied to the internal combustion engine 50 by changing the opening. The throttle body 13b is composed of a cylindrical member in which an intake passage is formed, and supports a valve shaft 13c of a throttle valve 13a disposed in the intake passage. The electric motor 13d is configured to change the opening degree of the throttle valve 13a under the control of the ECU 40A, and a step motor is adopted as the electric motor 13d. The electric motor 13d is fixed to the throttle body 13b, and its output shaft (not shown) is connected to the valve shaft 13c. The opening degree of the throttle valve 13a is detected by the ECU 40A based on an output signal from a throttle opening degree sensor (not shown) built in the electric throttle 13.

  In addition to the throttle-by-wire system in which the throttle valve 13a such as the electric throttle 13 is driven by an actuator, the throttle mechanism is linked to an accelerator pedal (not shown) via a wire or the like instead of the electric throttle 13, and the throttle valve A mechanical throttle mechanism in which the opening degree of 13a is changed may be applied. The intake manifold 14 is configured to branch one intake passage on the upstream side corresponding to each cylinder of the internal combustion engine 50 on the downstream side, and distributes intake air to each cylinder of the internal combustion engine 50.

  The brake device 20 includes a brake pedal 21, a brake booster (negative pressure operating device) 22, a master cylinder 23, and a wheel cylinder (not shown). The brake pedal 21 operated by the driver to brake the rotation of the wheel is connected to an input rod (not shown) of the brake booster 22. The brake booster 22 is configured to generate an assist force with a predetermined boost ratio with respect to the pedal depression force, and a negative pressure chamber (not shown) internally partitioned on the master resin 23 side To the intake passage of the intake manifold 14. The output rod (not shown) of the brake booster 22 is further connected to the input shaft (not shown) of the master cylinder 23. The master cylinder 23 receives the assist force in addition to the pedal depression force. Hydraulic pressure is generated according to the applied force. The master cylinder 23 is connected to each wheel cylinder provided in a disc brake mechanism (not shown) of each wheel via a hydraulic circuit, and the wheel cylinder generates a braking force with the hydraulic pressure supplied from the master cylinder 23. . The brake booster 22 is not particularly limited as long as it is a pneumatic type, and may be a general one.

  The ejector 30 generates a negative pressure larger than the negative pressure (intake pipe negative pressure) to be taken out from the intake system 10, more specifically, the intake manifold 14 on the downstream side of the throttle valve 13 a, thereby generating the brake booster 22. It is the structure for supplying to the negative pressure chamber. The ejector 30 has an inflow port 31a, an outflow port 31b, and a negative pressure supply port 31c. Among these, the negative pressure supply port 31c is connected to the negative pressure chamber of the brake booster 22 by the air hose 5c. The inflow port 31a is connected to the intake passage of the intake pipe 15a by an air hose 5a, and the outflow port 31b is connected to the intake passage of the intake manifold 14 by an air hose 5b so as to sandwich the electric throttle 13, more specifically, the throttle valve 13a. ing. Thus, a bypass path B that bypasses the electric throttle 13 is formed by the air hoses 5 a and 5 b including the ejector 30. When the ejector 30 is not functioning, the negative pressure chamber of the brake booster 22 is connected to the intake manifold 14 via the air hose 5b, the outlet port 31b of the ejector 30, the negative pressure supply port 31c, and the air hose 5c. Negative pressure is supplied.

  A VSV (vacuum switching valve) 1 is interposed in the air hose 5a. The VSV 1 is configured to communicate and block the bypass path B based on the control of the ECU 40A. In this embodiment, a normally closed solenoid valve having two positions and two ports is employed. However, the present invention is not limited to this, and the VSV 1 may be another appropriate electromagnetic valve or the like, and may be, for example, a flow rate adjustment valve that can control the degree of shielding of the flow path. The VSV 1 is configured to cause the ejector 30 to function or stop functioning by communicating and blocking the bypass path B. In the present embodiment, the state changing means is realized by VSV1.

  FIG. 2 is a diagram schematically showing the internal configuration of the ejector 30. The ejector 30 includes a diffuser 32 inside. The diffuser 32 includes a tapered taper portion 32a, a divergent taper portion 32b, and a negative pressure extraction portion 32c corresponding to a passage communicating these. The tapered taper portion 32a is opened so as to face the inflow port 31a, and the divergent taper portion 32b is opened so as to face the outflow port 31b. Moreover, the negative pressure extraction part 32c is connected to the negative pressure supply port 31c. The inflow port 31a is provided with a nozzle 33 for injecting the inflowing intake air toward the tapered portion 32a. The intake air injected from the nozzle 33 flows through the diffuser 32, and further from the outflow port 31b to the air hose 5b. To leak. At this time, a high-speed jet is generated in the diffuser 32 to generate a large negative pressure in the negative pressure extraction portion 32c due to the venturi effect, and this negative pressure is further reduced from the negative pressure supply port 31c through the air hose 5c to the negative pressure chamber. To be supplied. Due to the function of the ejector 30, the brake booster 22 can obtain a larger negative pressure than when the brake booster 22 is taken out from the intake manifold 14.

  The internal flow path between the negative pressure extraction part 32c and the negative pressure supply port 31c, the internal flow path between the outflow port 31b and the negative pressure supply port 31c, and the air hose 5c connection part of the brake booster 22 The provided check valves 34 are for preventing backflow. Further, the ejector 30 is not limited to the one having the internal structure shown in FIG. 2, and an ejector having another different internal structure may be applied instead of the ejector 30. In this embodiment, the negative pressure generating device 100 is realized by including the VSV 1 and the ejector 30. More specifically, the negative pressure generating device 100 has air hoses 5a, 5b and 5c and a check valve 34. Configured.

  The ECU 40A is a microcomputer (hereinafter simply referred to as a microcomputer) that includes a CPU (Central Processing Unit), a ROM (Read Only Memory), and a RAM (Random Access Memory) (not shown). And an input / output circuit. The ECU 40A mainly has a configuration for controlling the internal combustion engine 50. In this embodiment, the ECU 40A also controls the VSV 1, the electric throttle 13, and the like. In addition to the VSV 1 and the electric throttle 13, various control objects are connected to the ECU 40A. Further, the ECU 40A includes various types such as an air flow meter 12, a throttle opening sensor, a water temperature sensor 71 for detecting the water temperature of the internal combustion engine 50, and a crank angle sensor 72 for detecting the rotational speed NE of the internal combustion engine 50. Sensor is connected.

  The ROM is configured to store a program in which various processes executed by the CPU are described. In this embodiment, in addition to the program for controlling the internal combustion engine 50, the ejector 30 functions under various conditions. Alternatively, a VSV1 control program for controlling the VSV1 so as to stop the function (hereinafter simply referred to as opening or closing the VSV1) is also stored. Note that these programs may be combined together. The VSV1 control program has a negative pressure securing program for opening the VSV1 in order to secure a negative pressure in the brake booster 22 using the ejector 30 during the low temperature start warm-up process. In the present embodiment, this negative pressure securing program is created so that VSV1 is opened when it is cold (for example, when the water temperature is 75 ° C. or less), and VSV1 is closed when it is warm. Therefore, VSV1 is basically opened in the cold state and closed in the warm state based on the negative pressure ensuring program.

  In this embodiment, the VSV 1 control program determines whether or not freezing has occurred according to the change in the flow rate of the intake air flowing through the ejector 30 when the VSV 1 is opened during the cold start warm-up process. It has a determination program. In this embodiment, the freeze occurrence determination program is specifically created so that the determination is made during cold idling when the internal combustion engine 50 is in a steady operation state. Further, since it can be said that there is no possibility of freezing when the intake air temperature is sufficiently high, the freezing occurrence determination program is created so as to make a determination only when the intake air temperature is lower than a predetermined value.

  Further, this freezing occurrence determination program specifically determines whether or not the flow rate of the intake air flowing through the ejector 30 has suddenly decreased, and determines that freezing has occurred when the flow rate suddenly decreases. Has been created. In this regard, in this embodiment, the freezing occurrence determination program is more specifically applied to the ISC control for maintaining the idling engine speed at the target engine speed, based on whether or not the intake air flow rate flowing through the ejector 30 has suddenly decreased. The determination is made based on whether or not the control amount has changed by a predetermined value or more. When the control amount has changed by a predetermined value or more, it is determined that freezing has occurred. In the present embodiment, various control means, detection means, determination means, and the like are realized by the microcomputer and the various programs described above, and in particular, the freeze occurrence determination means is realized by the microcomputer and the freeze occurrence determination program.

  Next, processing performed by the ECU 40A will be described in detail with reference to the flowchart shown in FIG. The ECU 40A determines whether or not freezing has occurred in the negative pressure generating device 100 by repeatedly executing the processing shown in the flowchart in a very short time based on the various programs stored in the ROM. The CPU executes processing for determining whether or not it is after complete warm-up (step S11). Whether or not it is after the complete warm-up can be determined by whether or not the water temperature is a predetermined value (for example, 88 ° C.) or less. If a negative determination is made in step S11, no special processing is required in this flowchart, so the process returns and returns to step S11. On the other hand, if the determination in step S11 is affirmative, the CPU executes a process of determining whether VSV1 is ON (that is, whether it is open) (step S12). If a negative determination is made, no special processing is required in this flowchart, and the process returns and returns to step S11.

  On the other hand, if an affirmative determination is made in step S12, the CPU executes a process of determining whether or not the intake air temperature is equal to or lower than a predetermined value (step S13). This predetermined value is set to such a temperature that the intake air temperature is lowered to 0 ° C. or less by the ejector 30, and it is determined whether or not there is a possibility that the negative pressure generator 100 is frozen in this step. In this step, for example, it may be simultaneously determined whether or not the water temperature is equal to or higher than a predetermined value. If a negative determination is made in step S12, no special process is required in this flowchart, and the process returns and returns to step S11.

  On the other hand, if an affirmative determination is made in step S13, a process of storing a control amount related to ISC control is executed (step S14). Subsequently, the CPU executes a process of determining whether or not the difference between the newly stored control amount and the previously stored control amount is greater than or equal to a predetermined value (step S15). That is, in this step, it is determined whether or not the control amount related to ISC control has changed by a predetermined value or more. The predetermined value can be determined by previously grasping the control amount that changes when freezing occurs through experiments or the like. If a negative determination is made in step S15, it is determined that freezing has not occurred. At this time, since no special processing is required in this flowchart, the process returns and returns to step S11.

  On the other hand, if the determination in step S15 is affirmative, it is determined that freezing has occurred, and the CPU executes processing for turning on the freezing occurrence flag (step S16). As a result, the occurrence of freezing can be determined by the freezing occurrence flag, so that the freezing that occurs in the negative pressure generating device 100 can be dealt with suitably. It should be noted that an outside air temperature sensor for detecting the outside air temperature is further provided, and in the flowchart shown in FIG. 3, whether or not the outside air temperature detected by the outside air temperature sensor is equal to or lower than a predetermined value is determined instead in step S13. Good. This can be realized by creating a freeze occurrence determination program so that determination is made only when the outside air temperature is lower than a predetermined value instead of the intake air temperature. As described above, the ECU 40A that can appropriately cope with the freezing generated in the negative pressure generating device 100 can be realized.

  The ECU 40B according to the present embodiment is for cleaning control in which the VSV1 control program stored in the ROM opens the VSV1 when the F / C control is started according to the F / C control performed in the internal combustion engine 50A. For increasing the frequency of cleaning, which increases the frequency at which the VSV 1 is opened during the warm-up after the warm-up is completed when the negative pressure generator 100 is frozen while the VSV 1 is opened during the low-temperature start-up warm-up process. The ECU 40A according to the first embodiment is the same as the ECU 40 except that the program is further included. In addition, each structure with which the vehicle to which ECU40B is applied is the same as each structure shown in FIG. 1 except that ECU40A is changed to ECU40B. In the present embodiment, specifically, the cleaning control program opens the VSV 1 once according to the F / C control, passes a predetermined time (for example, 10 to 30 minutes), and then performs the F / C control. It is created to open VSV1 when it is disconnected.

  The cleaning frequency increasing program is a case where freezing has occurred in the negative pressure generator 100 when the VSV 1 is open during the low temperature start warm-up process. It is created so as to increase the frequency when the flag is ON. In the present embodiment, the cleaning frequency increasing program is specifically created based on the cleaning control program so as to increase the frequency with which the VSV 1 is opened in accordance with the F / C control. In this respect, in the present embodiment, more specifically, in the present embodiment, the cleaning frequency increasing program is created so that the predetermined time related to the cleaning control program can be shortened. For this reason, in the present embodiment, more specifically, the cleaning frequency increasing program is created so as to turn on the cleaning frequency increasing flag in increasing the frequency. It is created so as to shorten the predetermined time when the increase flag is ON.

  The F / C control program is configured as a part of the internal combustion engine 50 control program. The F / C control program is such that the accelerator pedal is released in a state where the rotational speed NE is high to some extent. In some cases, F / C is performed. In the present embodiment, the cleaning control means is realized by the microcomputer and the cleaning control program, and the cleaning frequency increasing means is realized by the microcomputer and the cleaning frequency increasing program, respectively, and the control device for the negative pressure generating device is realized by the ECU 40B. ing.

  Next, processing performed by the ECU 40B will be described in detail with reference to the flowchart shown in FIG. The CPU executes processing for determining whether or not deceleration F / C is being performed (step S21). If a negative determination is made, no special processing is required in this flowchart, and the process returns and returns to step S11. Subsequently, the CPU executes a process for determining whether or not the water temperature is higher than a predetermined value (for example, 88 ° C.) (step S22). That is, in this step, it is determined whether or not it is a warm time after complete warm-up. If a negative determination is made, no special processing is required in this flowchart, and the process returns and returns to step S11.

  On the other hand, if an affirmative determination is made in step S22, the CPU executes a process of determining whether or not the freezing occurrence flag is ON (step S23). If a negative determination is made, no special processing is required in this flowchart, and the process returns and returns to step S11. On the other hand, if an affirmative determination is made in step S23, the CPU executes a process of turning on a cleaning frequency increase flag (step S24). As a result, the predetermined time relating to the cleaning control program is shortened, so that the frequency at which the VSV 1 is opened during the warm-up after the complete warm-up can be increased. It is possible to prevent or suppress the complete blockage and to expect the effect of eliminating the generated freezing at an early stage. That is, it is possible to suitably cope with freezing that occurs in the negative pressure generator 100.

  When increasing the frequency, the frequency may be further increased when the intake air temperature (or outside air temperature) is higher than a predetermined value (a temperature at which the intake air temperature decreases to 0 ° C. or less by the ejector). Good. In this case, the cleaning frequency increasing program may be created so as to increase the frequency when the intake air temperature (or outside air temperature) is larger than a predetermined value. As described above, the ECU 40B that can suitably cope with freezing generated in the negative pressure generator 100 can be realized.

  The embodiment described above is a preferred embodiment of the present invention. However, the present invention is not limited to this, and various modifications can be made without departing from the scope of the present invention.

2 is a diagram schematically showing an ECU 40A together with a negative pressure generator 100. FIG. 3 is a diagram schematically showing an internal configuration of an ejector 30. FIG. It is a figure which shows the process performed by ECU40A with a flowchart. It is a figure which shows the process performed by ECU40B with a flowchart.

Explanation of symbols

1 VSV
10 Intake System 20 Brake Device 30 Ejector 40 ECU
50 Internal combustion engine 100 Negative pressure generator

Claims (4)

A negative pressure configured to include an ejector that generates a negative pressure larger than the negative pressure to be taken out from an intake passage of an intake system of an internal combustion engine provided in the vehicle, and a state changing unit that causes the ejector to function or stop functioning. A control device for a negative pressure generator for controlling the generator,
Freezing determination that determines whether or not freezing has occurred according to a change in the flow rate of the intake air flowing through the ejector when the state changing means is controlled to function the ejector during a cold start warm-up process A control device for a negative pressure generator, comprising: means. The freezing occurrence determination means determines whether or not the flow rate of the intake air flowing through the ejector has suddenly decreased, and determines that freezing has occurred when it suddenly decreases. The control apparatus of the negative pressure generator of 1. The freezing occurrence determining means is for maintaining the idling engine speed at a target engine speed to determine whether or not the intake flow rate flowing through the ejector has suddenly decreased during cold idling when the internal combustion engine is in a steady operation state. 3. The negative pressure generator according to claim 2, wherein determination is made based on whether or not a control amount related to ISC control has changed by a predetermined value or more, and if the control amount has changed by a predetermined value or more, it is determined that freezing has occurred. Control device. A negative pressure configured to include an ejector that generates a negative pressure larger than the negative pressure to be taken out from an intake passage of an intake system of an internal combustion engine provided in the vehicle, and a state changing unit that causes the ejector to function or stop functioning. A control device for a negative pressure generator for controlling the generator,
When the state change means is controlled to make the ejector function during the cold start warm-up process, when the negative pressure generator is frozen, the ejector functions in the warm state after the warm-up is completed. A control device for a negative pressure generating device, comprising: a cleaning frequency increasing means for increasing the frequency with which the state changing means is controlled.

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