JP2005188452A - Electronic controlled throttle device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To perform emergency run by a simple mechanism even if a throttle valve drive system of an electronic control throttle device fails. <P>SOLUTION: An electromagnetic clutch 18 is disengaged and a regulator 28 is controlled so that an engine rotation speed can be maintained in a prescribed range, when the drive system of a throttle valve 14 fails, in the electronic control throttle device including the throttle valve 14 rotated in one piece with a valve shaft 12, a motor 16 connected to one end of the valve shaft 12 via the electromagnetic clutch 18 and a reduction gear train 20 for rotating the throttle valve 14 according to the operation of an acceleration pedal, a spring 24 for rotating the throttle valve 14 to the fully closed position, a lever 22 mounted to the other end of the valve shaft 12, an air actuator 26 that comes into contact with the lever 22 or is arranged with a minute gap to the lever 22, and a regulator 28 for controlling the supply of compressed air to an air actuator 26. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a technique for enabling an emergency running with a simple mechanism even when a failure occurs in a drive system of a throttle valve in an electronically controlled throttle device.

In recent years, in order to improve the response to an accelerator operation, an electronically controlled throttle device that uses an electric actuator such as a motor and nonlinearly opens and closes a throttle valve according to an accelerator pedal operation has been put into practical use. An electronically controlled throttle device is disclosed in Japanese Patent Application Laid-Open No. 2002-349296 (Patent Document 1) to enable emergency traveling at a constant speed even if a failure occurs in a throttle valve drive system such as an electric actuator. Technologies have been proposed. In the proposed technique, when a failure occurs, the throttle valve is forcibly opened by a predetermined opening to generate a torque necessary for vehicle travel.
JP 2002-349296 A

  By the way, a large commercial vehicle such as a truck has a characteristic that the total weight of the vehicle changes greatly according to the weight of the load. For this reason, when the prior art is applied to a large commercial vehicle, the following problems may occur if the throttle valve is simply opened by a predetermined opening. That is, when the opening degree of the throttle valve is set in accordance with the loaded state, the engine load increases more than necessary because the traveling load is small in the empty state. On the other hand, if the opening degree of the throttle valve is set in accordance with the empty vehicle state, since the traveling load is large in the loaded state, an engine stall or the like is caused and the actual traveling becomes impossible.

  Therefore, in view of the conventional problems as described above, the present invention allows the engine rotation speed to be maintained within a predetermined range with a simple mechanism, thereby reducing the travel load that varies greatly in large commercial vehicles and the like. Regardless, it is an object of the present invention to provide an electronically controlled throttle device that enables emergency running in the event of a failure.

  Therefore, in the first aspect of the present invention, in order to rotate the throttle valve according to the accelerator pedal operation, and the throttle valve that rotates integrally with the valve shaft that is rotatably disposed in the intake passage, An electric actuator connected to one end of the valve shaft via an electromagnetic clutch, a spring for rotating the throttle valve to a fully closed position, and the other end of the valve shaft to swing integrally with the throttle valve A lever attached to the air actuator, an air actuator disposed in contact with the lever or spaced apart from the lever to open the throttle valve from a fully closed position, and a regulator for controlling the supply of working fluid to the air actuator; A failure determination means for determining whether or not a failure has occurred in the drive system of the throttle valve, an operation state detection means for detecting a vehicle operation state, and the failure determination means. When it is determined that a failure has occurred, the electromagnetic clutch is disengaged, and control means for controlling the regulator so that the engine rotational speed detected by the operating state detection means is maintained within a predetermined range; The electronic control throttle device is configured including the above.

The invention according to claim 2 is characterized in that the control means starts control of the regulator when the operating state detecting means detects that the transmission is in a neutral position.
According to a third aspect of the present invention, there is provided traveling condition determining means for determining whether or not a vehicle traveling condition is established, and the control means is configured to determine when the traveling condition is established by the traveling condition determining means. The control of the regulator is started.

According to a fourth aspect of the present invention, the travel condition determining means determines that the vehicle travel condition is satisfied when the driving state detecting means shifts the transmission from the neutral position to the travel stage. .
According to a fifth aspect of the invention, there is provided deceleration condition determining means for determining whether or not a vehicle deceleration condition is satisfied, and the control means is determined when the deceleration condition determining means determines that the vehicle deceleration condition is satisfied. The regulator is controlled to discharge the working fluid from the air actuator.

  According to a sixth aspect of the present invention, the deceleration condition determining means detects that the operating state detecting means has detected that the transmission has been shifted to the neutral position, or that the brake has been actuated and the engine rotational speed has been reduced. Sometimes, it is determined that the vehicle deceleration condition is satisfied.

  According to the first aspect of the present invention, the main body of the electronically controlled throttle device includes a throttle valve that rotates integrally with a valve shaft that is rotatably disposed in the intake passage, and a throttle that operates in response to an accelerator pedal operation. An electric actuator connected to one end of the valve shaft via an electromagnetic clutch to rotate the valve, a spring to rotate the throttle valve to the fully closed position, and a valve shaft to swing integrally with the throttle valve A lever attached to the other end of the actuator, an air actuator disposed in contact with the lever or spaced apart from the lever to open the throttle valve from the fully closed position, and a regulator for controlling the supply of working fluid to the air actuator; It is comprised including. When a failure occurs in the drive system of the throttle valve, the electromagnetic clutch is disconnected, so that the throttle valve is disconnected from the electric actuator that rotates it, and is rotated to the fully closed position by the biasing force of the spring. Further, the regulator is controlled so that the engine rotational speed is maintained within a predetermined range as the electromagnetic clutch is disconnected. That is, by controlling the regulator, the operation amount of the air actuator is controlled to increase or decrease, and the opening of the throttle valve is increased or decreased by swinging the lever. Therefore, the engine rotational speed can be maintained within a predetermined range with a simple mechanism, and emergency traveling in the event of a failure can be made possible regardless of the traveling load that varies greatly in a large commercial vehicle or the like. On the other hand, since the air actuator and the lever are not mechanically connected and are arranged in contact or at a small interval, the regulator is not controlled when there is no failure in the drive system of the throttle valve. In both cases, the opening degree of the throttle valve is controlled according to the accelerator pedal operation by the electric actuator.

According to the second aspect of the invention, as a condition for shifting to the emergency running, the vehicle driver can temporarily prevent the vehicle from accelerating unexpectedly by adding an operation of shifting the transmission to the neutral position. Can increase the sex.
According to the third aspect of the present invention, the control of the regulator is started so that the engine speed is maintained within the predetermined range when the vehicle traveling condition is satisfied. The required increase in engine speed can be prevented, and a reduction in fuel consumption and exhaust properties can be suppressed.

According to the fourth aspect of the present invention, when the transmission is shifted from the neutral position to the traveling stage, it is determined that the vehicle traveling condition is satisfied. Therefore, the vehicle traveling operation by the vehicle driver is reflected with high accuracy. However, it is possible to prevent the vehicle travel determination control from becoming complicated.
According to the fifth aspect of the present invention, when the vehicle deceleration condition is satisfied, the regulator is controlled to discharge the working fluid from the air actuator, so that the throttle valve rotates to the fully closed position by the biasing force of the spring. By effectively utilizing the so-called engine brake, deceleration performance can be ensured.

  According to the sixth aspect of the present invention, it is determined that the vehicle deceleration condition is satisfied when the transmission is shifted to the neutral position or when the brake is operated and the engine rotational speed is reduced. It is possible to prevent the vehicle deceleration determination control from being complicated while reflecting the intention to decelerate with high accuracy.

Hereinafter, the present invention will be described in detail with reference to the accompanying drawings.
FIG. 1 shows the overall configuration of an electronically controlled throttle device embodying the present invention.
A throttle valve 14 integrated with a valve shaft 12 is rotatably disposed in an intake passage 10 of the internal combustion engine. The output of the motor 16 as an electric actuator is transmitted to one end of the valve shaft 12 through an electromagnetic clutch 18 and a reduction gear train 20 so as to be connected and disconnected. On the other hand, a lever 22 that swings integrally with the throttle valve 14 is attached to the other end of the valve shaft 12. A spring 24 that rotates the throttle valve 14 to the fully closed position is attached to the valve shaft 12.

  At a position facing the lever 22, an air actuator 26 that rotates the throttle valve 14 by pushing the lever 22 by the operating rod 26 </ b> A is disposed. As shown in FIG. 2, it is desirable to select the air actuator 26 in which the operating rod 26 </ b> A changes substantially linearly according to the air pressure supplied to the input port. The lever 22 and the actuating rod 26A of the actuator 26 are not mechanically connected, and are disposed at a position where the throttle valve 14 is fully closed, with contact or at a small interval. An electronically controlled regulator (pressure adjusting valve) 28 is provided to supply compressed air, which is a working fluid, to the air actuator 26 so that the pressure can be adjusted. Compressed air is supplied to the regulator 28 from an air reservoir 32 in which air compressed to a predetermined pressure by the air compressor 30 is stored. As the air reservoir 32, it is preferable to use an air reservoir that supplies compressed air to an air brake employed in a large commercial vehicle or the like.

The intake passage 10 is provided with a bypass passage 34 that bypasses the throttle valve 14 to perform idle rotation speed control, and an electronically controlled idle control that opens and closes the flow passage area of the bypass passage 34 so as to be adjustable. A valve 36 is provided.
Further, as a control system of the electronically controlled throttle device, an opening sensor 38 for detecting the opening of the throttle valve 14 (hereinafter referred to as “throttle opening”) is attached to one end of the valve shaft 12. Then, a throttle opening signal from the opening sensor 38, an accelerator opening signal indicating an accelerator pedal operation amount, a brake operation signal, a clutch connecting / disconnecting signal of a clutch for connecting / disconnecting the internal combustion engine and the transmission, an engine speed signal The gear position signal and the vehicle speed signal of the transmission are input to a control device 40 incorporating a computer, and the motor 16, the electromagnetic clutch 18, the regulator 28, and the idle control valve are controlled by a control program stored in a ROM (Read Only Memory). 36 are controlled respectively. Note that the accelerator opening signal, the brake operation signal, the clutch engagement / disconnection signal, the engine rotation speed signal, the gear position signal, and the vehicle speed signal are read from various sensors via a CAN (Controller Area Network), for example. Here, the opening degree sensor 38 and various sensors constitute an operation state detection unit, and a failure determination unit, a control unit, a travel condition determination unit, and a deceleration condition determination unit are realized by the control program of the control device 40, respectively. The

FIG. 3 is a flowchart showing the control content of the electronically controlled throttle device that is repeatedly executed every predetermined time.
In step 1 (abbreviated as “S1” in the figure, the same applies hereinafter), it is determined whether or not a failure has occurred in the motor 16 or the like as the drive system of the throttle valve 14. Whether or not a failure has occurred can be determined indirectly, for example, through a phenomenon in which the torque does not change despite an increase in the opening of the throttle valve 14. If a failure has occurred, the process proceeds to step 2 (Yes), and if no failure has occurred, the process proceeds to step 11 (No).

  In step 2, the electromagnetic clutch 18 is disconnected to disconnect the throttle valve 14 from the motor 16. When the electromagnetic clutch 18 is disconnected, the throttle valve 14 is rotated to the fully closed position by the urging force of the spring 24 attached to the valve shaft 12 and shifts to the idle state. In the idle state, the idle control valve 36 is controlled based on the engine rotation speed signal or the like so that the engine rotation speed approaches the target idle rotation speed.

  In step 3, whether or not the transmission is in the neutral position based on the clutch connection / disconnection signal and the gear position signal, specifically, whether or not the transmission is shifted to the neutral position and the clutch is engaged. (The same applies hereinafter) is determined. That is, as a condition for shifting to the emergency running, the vehicle driver can temporarily prevent the vehicle from accelerating unexpectedly by adding an operation of shifting the transmission to the neutral position, thereby improving safety. If the transmission is in the neutral position, the process proceeds to step 4 (Yes), while if the transmission is not in the neutral position, the process waits (No).

In step 4, a subroutine (see FIG. 4) for maintaining the engine speed within a predetermined range is called to prepare for the transition to emergency running.
In step 5, whether or not the driving condition is satisfied from the clutch connecting / disconnecting signal and the gear position signal, specifically, the vehicle driver shifts the transmission to the driving stage and connects the clutch to drive the vehicle. It is determined whether or not. If the traveling condition is satisfied, the process proceeds to Step 6 (Yes), while if the traveling condition is not satisfied, the process waits (No).

In step 6, a subroutine (see FIG. 4) for maintaining the engine speed within a predetermined range regardless of the travel load is called to enable emergency travel.
In step 7, it is determined whether the deceleration condition is satisfied. Here, the deceleration conditions include whether the transmission is in the neutral position from the clutch engagement / disconnection signal and the gear position signal, or the brake is operated and the engine rotation speed is decreased from the brake operation signal and the engine rotation speed signal. You can apply whether or not. If the deceleration condition is satisfied, the process proceeds to step 8 (Yes). If the deceleration condition is not satisfied, the process returns to step 6 to continue the emergency traveling (No).

In step 8, all the air is discharged from the air actuator 26, and the regulator 28 is controlled so that the throttle valve 14 is fully closed by the urging force of the spring 24.
In step 9, it is determined whether or not the transmission is in a neutral position from the clutch engagement / disconnection signal and the gear position signal. If the transmission is in the neutral position, the process proceeds to step 10 (Yes), while if the transmission is not in the neutral position, the process returns to step 7 (No).

In step 10, it is determined from the vehicle speed signal whether the vehicle has stopped, specifically, whether the vehicle speed has become substantially zero. If the vehicle stops, the process returns to step 4 in preparation for the next run (Yes), while if the vehicle does not stop, the process returns to step 7 (No).
In step 11, the motor 16 is feedback-controlled according to the throttle opening signal from the opening sensor 38 so that the throttle opening corresponding to the accelerator opening signal is obtained.

FIG. 4 shows a flowchart of a subroutine for maintaining the engine speed within a predetermined range.
In step 21, it is determined whether or not the actual rotational speed indicated by the engine rotational speed signal is higher than a target rotational speed at which emergency traveling is possible. If the actual rotational speed is greater than the target rotational speed, the process proceeds to step 22 (Yes). On the other hand, if the actual rotational speed is equal to or lower than the target rotational speed, the process proceeds to step 23 (No), and the regulator 28 is controlled to increase the air pressure supplied to the air actuator 26. When the air pressure of the air actuator 26 increases, as shown in FIG. 2, the operating amount of the operating rod 26 </ b> A increases, so that the valve shaft 12 rotates in the direction to open the opening of the throttle valve 14 via the lever 22. However, the actual rotational speed increases as the torque increases.

  In step 22, it is determined whether or not the actual rotation speed is equal to or less than the addition value of the target rotation speed and the predetermined value α. Here, the predetermined value α is for suppressing frequent increase / decrease control of the actual rotational speed and preventing hunting. If the actual rotational speed is equal to or less than the addition value of the target rotational speed and the predetermined value α, the actual rotational speed is maintained within the predetermined range, and the process ends (Yes). On the other hand, if the actual rotational speed is larger than the sum of the target rotational speed and the predetermined value α, the process proceeds to step 24 (No), and the regulator 28 is controlled so as to reduce the air pressure supplied to the air actuator 26. To do. When the air pressure of the air actuator 26 decreases, as shown in FIG. 2, the operating amount of the operating rod 26A decreases, so that the valve shaft 12 rotates in a direction to close the opening of the throttle valve 14 by the biasing force of the spring 24. The actual rotational speed is lowered by the torque being reduced.

  According to such control contents, when a failure occurs in the drive system of the throttle valve 14, the throttle valve 14 is disconnected from the motor 16, and is rotated to the fully closed position by the urging force of the spring 24 to shift to emergency running. To do. At this time, by adding that the transmission is shifted to the neutral position as a condition for transition to emergency traveling, unexpected acceleration of the vehicle driver can be prevented and safety can be improved. Since the engine speed is maintained within a predetermined range in preparation for vehicle start, the torque required for vehicle start is ensured and smooth vehicle start can be performed. Also, during emergency travel where the transmission is shifted to the travel stage and the clutch is connected, the engine speed is similarly maintained within a predetermined range, so regardless of the travel load that changes from moment to moment depending on the travel conditions, etc. The vehicle can be run. Thereafter, when the deceleration condition is satisfied, all the air is discharged from the air actuator 26 and the throttle valve 14 is fully closed, so that the so-called engine brake can be effectively used and the deceleration performance can be ensured. .

  Here, in order to maintain the engine rotational speed within a predetermined range, the lever 22 attached to the other end of the valve shaft 12 is pushed out by an air actuator 26 using compressed air as a drive source, and the throttle valve 14 is rotationally driven. By adopting the configuration, a simple and inexpensive electronic control throttle device can be constructed. On the other hand, since the operating rod 26A of the air actuator 26 and the lever 22 are not mechanically connected, the motor 16 can be operated without operating the air actuator 26 at all when there is no failure in the drive system of the throttle valve 14. Thus, the throttle valve 14 can be controlled in accordance with the accelerator pedal operation.

  In the control content described above, it is added that the clutch is connected as a condition for determining whether or not the transmission is in the neutral position. However, in an automatic transmission equipped with a torque converter, the clutch Needless to say, the condition of connection is unnecessary.

1 is an overall configuration diagram of an electronically controlled throttle device embodying the present invention. Illustration of control characteristics of air actuator Flow chart showing control contents of electronically controlled throttle device A flowchart showing a subroutine for maintaining the engine speed within a predetermined range.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Intake passage 12 Valve shaft 14 Throttle valve 16 Motor 18 Electromagnetic clutch 22 Lever 24 Spring 26 Air actuator 28 Regulator 38 Opening sensor 40 Control apparatus

Claims (6)

A throttle valve that rotates integrally with a valve shaft that is rotatably disposed in the intake passage;
An electric actuator coupled to one end of the valve shaft via an electromagnetic clutch to rotate the throttle valve in response to an accelerator pedal operation;
A spring for rotating the throttle valve to a fully closed position;
A lever attached to the other end of the valve shaft to swing integrally with the throttle valve;
An air actuator disposed in contact with the lever or at a small interval to open the throttle valve from a fully closed position;
A regulator for controlling the supply of working fluid to the air actuator;
Failure determination means for determining whether a failure has occurred in the throttle valve drive system; and
Driving state detection means for detecting the vehicle driving state;
When the failure determination means determines that a failure has occurred, the electromagnetic clutch is disengaged and the regulator is controlled so that the engine speed detected by the operating state detection means is maintained within a predetermined range. Control means to
An electronically controlled throttle device comprising:   2. The electronic control throttle device according to claim 1, wherein the control means starts control of the regulator when it is detected by the driving state detection means that the transmission is in a neutral position. A traveling condition determining means for determining whether or not the vehicle traveling condition is satisfied;
2. The electronic control throttle device according to claim 1, wherein the control means starts control of the regulator when it is determined by the travel condition determination means that a vehicle travel condition is established.   4. The electronically controlled throttle according to claim 3, wherein the traveling condition determining means determines that the vehicle traveling condition is satisfied when the transmission is shifted from the neutral position to the traveling stage by the driving state detecting means. apparatus. A deceleration condition determining means for determining whether or not a vehicle deceleration condition is satisfied;
The said control means controls the said regulator so that a working fluid may be discharged | emitted from the said air actuator, when it determines with the deceleration condition determination means having satisfied vehicle deceleration conditions. Item 5. The electronically controlled throttle device according to any one of item 4.   The deceleration condition determining means satisfies the vehicle deceleration condition when the driving state detecting means detects that the transmission has been shifted to a neutral position or when a brake is applied and a decrease in engine speed is detected. 6. The electronically controlled throttle device according to claim 5, wherein the electronically controlled throttle device is determined as having been performed.

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