JPH0521630Y2 - - Google Patents

Description

[Detailed Description of the Invention] [Purpose of the Invention] (Field of Industrial Application) This invention relates to a vehicle speed limiting device that limits the maximum vehicle speed in, for example, an internal combustion engine of a light vehicle.

(Prior Art) A device for limiting the maximum vehicle speed of an internal combustion engine of a light vehicle is equipped with means for detecting the vehicle speed using a vehicle speed sensor, and means for detecting the amount of fuel or air supplied to the engine. When a predetermined maximum speed is detected, the amount of fuel and air is regulated based on the signal to prevent engine output and limit vehicle speed.

For example, when the fuel supply system is a carburetor type, an actuator such as a solenoid is provided in the fuel passage leading to the main fuel jet, and the actuator is actuated by a signal from the vehicle speed detection means. In the case of an injection method, the injector is stopped in response to a signal from the vehicle speed detection means. In addition, as a method for limiting the amount of air, a throttle valve or an air amount limiting valve provided upstream of the throttle valve installation position is closed by an actuator that operates based on a signal from a vehicle speed detection means. ing.

(Problems to be Solved by the Invention) However, the method of limiting the amount of fuel described above is likely to cause backfire, and the method of limiting the amount of air is poor in fuel efficiency.
In addition, as a supercharger control device, Japanese Patent Application Laid-Open No. 59-147890
This is known from the publication No. 1, but this is because a mechanical supercharger is installed upstream of the throttle valve.
Not only is this disadvantageous in terms of noise, but it also reduces the efficiency with which the engine is charged, resulting in a lack of power.

This idea was devised by focusing on the above-mentioned circumstances, and its purpose is to reduce the supercharging pressure to a predetermined level by increasing the amount of bypass bypassing the inlet and outlet sides of the supercharger. To provide a vehicle speed limiting device capable of limiting vehicle speed to

[Structure of the invention] (Means and effects for solving the problems) This invention provides an intake passage of an internal combustion engine mounted on a vehicle, a throttle valve provided in the intake passage, and the throttle valve of the intake passage. A supercharger provided downstream of the valve, a piston portion provided upstream of the throttle valve in the intake passage and sliding to proportionally control the intake area of the intake passage and the nozzle opening area for fuel supply; The chamber includes a chamber separated from the intake passage by a piston control diaphragm connected to the piston control diaphragm, and a first spring that biases the piston portion in a direction in which the suction area and nozzle opening area are reduced. a variable bench lily carburetor that moves the piston portion in a direction in which the suction area and nozzle opening area increase in conjunction with the piston control diaphragm that is moved by negative pressure generated by the intake air flow passing through the intake passage; A bypass passage provided in parallel with the intake passage and communicating between the inlet side and the outlet side of the supercharger, a bypass valve provided in the bypass passage to open and close the bypass passage, and a gap between the supercharger and the throttle valve. a first chamber communicating with the intake passage of the supercharger; a second chamber communicating with the intake passage downstream of the supercharger; a bypass valve control section comprising a valve control diaphragm and a second spring biasing the bypass valve in the opening direction; the chamber of the variable bench yoke carburetor; and the second chamber and atmosphere side of the bypass valve control section. A solenoid valve that communicates or disconnects the vehicle, a vehicle speed sensor that detects the vehicle speed of the vehicle, and a control relay that drives the solenoid valve based on a signal from the vehicle speed sensor, the vehicle speed detected by the vehicle speed sensor being a predetermined value. At this time, the solenoid valve is driven by the relay to connect the chamber and the atmosphere side and move the piston part in a direction in which the suction area and the nozzle opening area are decreased, and the second chamber and the atmosphere side are moved. The bypass valve is moved in the opening direction.

Therefore, when the vehicle speed exceeds a predetermined value, the control relay drives the solenoid valve to establish communication between the chamber and the second chamber and the atmosphere side.
When the chamber and the atmosphere side are communicated, the first
The piston part is moved in the direction where the suction area and the nozzle opening area are reduced by the urging force of the spring, and at the same time, the second chamber and the atmosphere side are communicated with each other.
The bypass valve is moved in the opening direction by the biasing force of the spring. Therefore, the intake area of the variable bench yoke carburetor and the area of the fuel supply nozzle are narrowed down, and at the same time, the intake air supercharged by the supercharger is circulated through the bypass path, reducing the supercharging pressure. The amount of fuel and air supplied to the engine is limited.

(Example) An example of this invention will be described below with reference to the drawings.

FIG. 1 shows the overall structure of a vehicle speed limiting device for an internal combustion engine, where 1 is an engine, 2 is an intake passage, and 3 is an exhaust passage. A variable bench valve carburetor 4 is provided in the intake passage 2, and a throttle valve 5 is provided on the downstream side thereof.
Furthermore, a mechanical supercharger 6 is provided in the intake passage 2 on the downstream side of the throttle valve 5.

First, the variable bench lily carburetor 4 will be explained. 7 is a carburetor main body, and this main body 7 is provided with a bench lily portion 9 having an inner bench lily 8, into which fuel is supplied. A main nozzle 10 and a sub nozzle 11 are provided adjacent to the main nozzle 10. Further, a suction chamber 13 is provided at the upper part of the main body 7, and a suction piston 14 as a piston portion is provided inside the suction chamber 13 so as to be movable up and down. This suction piston 14 is moved downward by a first spring 15.
In other words, it is biased in a direction that reduces the opening amount of the intake passage 2. Furthermore, this suction piston 14 is inserted into the sub-nozzle 11,
A jet needle 16 for varying the opening amount of the sub nozzle 11 is integrally provided. Further, the suction piston 14 is provided with a suction port 17 that communicates the suction chamber 13 and the bench lily portion 9, and the peripheral wall of the flange portion of the suction piston 14 and the inner peripheral wall of the suction chamber 13 are connected to each other. are connected by a piston control diaphragm 18.

When the throttle valve 5 rotates and the throttle opening increases, the amount of air passing through the bench lily portion 9 increases and its flow velocity increases. Along with this, the static pressure of the bench lily portion 9 decreases (negative pressure increases), and the main nozzle 10 and the sub nozzle 1
The amount of fuel increases from 1 to obtain a predetermined air-fuel ratio. Furthermore, when the engine is in a high load range and the opening degree of the throttle valve 5 is further increased, and the intake load increases, the air in the suction chamber 13 is sucked out through the suction port 17, and the suction chamber Increase the negative pressure of the bar 13. When the negative pressure in the suction chamber 13 overcomes the biasing force of the first spring 15, the suction piston 14 moves into the suction chamber 13, that is, retreats from the intake passage 2 and moves into the bench lily portion 9. Increase the opening amount. This reduces the flow resistance, reduces pressure loss, increases the intake air amount of the engine 1, and increases the engine output.

Next, the supercharger 6 and its surroundings will be explained. The supercharger 6 is rotatably driven in conjunction with the engine 1, and the inlet side 6a and outlet side 6b of the supercharger 6 are They are communicated by a bypass path 20. An auxiliary valve seat 21 is provided in the middle of the bypass passage 20, and a bypass valve 22 for opening and closing the bypass passage 20 is provided on the auxiliary valve seat 21. As shown in FIG. 2, this bypass valve 22 is configured to open and close in two stages. That is, 23 is an auxiliary valve joined to the auxiliary valve seat 21, and this auxiliary valve 23 is provided with a main valve seat 24,
A main valve 25 is provided on this main valve seat 24 .
The auxiliary valve 23 is connected to the auxiliary valve seat 21 by a spring 26, and is linked to the bypass valve control section 28 via the valve rod 27 of the main valve 25. The working chamber 29 constituting the valve control section 28 is divided into an upper chamber 31 and a lower chamber 32 by a valve control diaphragm 30, and the diaphragm 30 and the valve rod 27 are connected. Further, the diaphragm 30 is biased downward by the second spring 33, that is, in the direction to open the main valve 25. Further, the upper chamber 31 communicates with an upstream side 35 (negative pressure) as a first chamber of the supercharger 6 via a negative pressure passage 34, and the lower chamber 32 communicates with an upstream side 35 (negative pressure) via a supercharging pressure control passage 36. It communicates with a downstream side 37 (positive pressure) as a second chamber of the supercharger 6. Furthermore, this boost pressure control passage 36
A solenoid valve 38 is provided in the middle of the
This solenoid valve 38 is electrically connected to a vehicle speed sensor 40 via a control relay 39.
The solenoid valve 38 has a first passage 41 and a second passage 42, and the first passage 41 communicates with an air supply passage 44 equipped with an air cleaner 43 that communicates with the atmosphere. Suction chamber 1 of variable bench yuri carburetor 4
It is connected to 3. Further, the second passage 42 communicates with the boost pressure control passage 36, and the first and second passages 41, 42 are normally closed, but when the solenoid valve 38 is activated, that is, The vehicle speed sensor 40 detects a predetermined maximum speed (for example, 90 km/h).
h or higher) and is turned on.

Next, the operation of the vehicle speed limiting device configured as described above will be explained. When the engine 1 is started, the solenoid valve 38 is turned off by a signal from the control unit, and the first and second passages 41 and 42 are closed. Therefore,
The air supply passage 44 and the boost pressure control passage 36 are in a closed state. When the throttle valve 5 rotates and the throttle opening increases, the amount of air passing through the bench lily portion 9 increases and its flow velocity increases. Along with this, the static pressure of the bench lily portion 9 decreases (negative pressure increases), and the main nozzle 10 and the sub nozzle 1
The amount of fuel increases from 1 to obtain a predetermined air-fuel ratio. Furthermore, when the engine is in a high load range and the opening degree of the throttle valve 5 is further increased and the air load increases, the air in the suction chamber 13 is sucked out through the suction port 17, and the suction chamber is Increase the negative pressure of the bar 13. When the negative pressure in the suction chamber 13 overcomes the biasing force of the first spring 15, the suction piston 14 moves into the suction chamber 13, that is, retreats from the intake passage 2 and moves into the bench lily portion 9. Increase the opening amount. This reduces the flow resistance, reduces pressure loss, increases the intake air amount of the engine 1, and increases the engine output. When the output of the engine 1 increases, the vehicle runs at a high speed, and when the vehicle speed reaches a predetermined maximum speed, an activation signal is input from the vehicle speed sensor 40 to the control relay 39. Therefore, the solenoid 38 is turned on and the first and second passages 41 and 42 are opened. When the first passage 41 is opened, atmospheric pressure is supplied to the suction chamber 13 of the variable bench yoke carburetor 4 via the air supply passage 44 via the air cleaner 43.
to go into. Therefore, the suction chamber 13 is opened to the atmosphere and has atmospheric pressure, and the suction piston 14 is pushed downward by the first spring 15. By pushing the suction piston 14, the opening area of the bench lily portion 9 is rapidly narrowed.
The amount of air taken into the engine decreases. Therefore, the ratio of air and fuel changes rapidly, the output of the engine 1 decreases, and the vehicle speed is limited (decreased).

Further, at the same time, when the second passage 42 is opened by the operation of the solenoid valve 38,
The boost pressure on the downstream side 37 of the supercharger 6 is supplied to the lower chamber 32 of the working chamber 29 of the bypass valve 22 via the boost pressure control passage 36 . Therefore, the pressure in the lower chamber 32 becomes higher than that in the upper chamber 31 due to the boost pressure, and the diaphragm 3 resists the biasing force of the second spring 33.
Push up 0. Due to the upward movement of the diaphragm 30, the main valve 25 is moved to the main valve seat 2 via the valve stem 27.
4, the bypass path 20 is opened. Therefore, the inlet side 6a and the outlet side 6b of the supercharger 6 are in communication via the bypass passage 20, and the amount of bypass increases. Even if the supercharger 6 operates normally, the amount of bypass increases. As a result, the supply of supercharged air to the engine 1 is restricted, and as a result, the output of the engine 1 is reduced and the vehicle speed is restricted.

In addition, a bypass valve 22 provided in the bypass path 20
By configuring the supercharger 6 in a two-stage opening/closing type,
When the pressure on the downstream side 37 of the main valve increases abnormally, the auxiliary valve 23 is separated from the auxiliary valve seat 21 and the bypass passage 20 can be instantly opened together with the main valve 25, improving safety.

[Effect of idea]

As explained above, according to this invention, when the vehicle speed exceeds a predetermined value, the control relay drives the solenoid valve to establish communication between the chamber and the second chamber and the atmosphere side. When the chamber and the atmosphere side are brought into communication, the piston part is moved in a direction in which the suction area and the nozzle opening area are reduced by the urging force of the first spring, and at the same time, when the second chamber and the atmosphere side are brought into communication. The biasing force of the second spring moves the bypass valve in the opening direction.

Therefore, the intake area of the variable bench yoke carburetor and the area of the fuel supply nozzle are narrowed down, and at the same time, the intake air supercharged by the supercharger is circulated through the bypass path, reducing the supercharging pressure. Since the amount of fuel and air supplied to the engine is limited, the output is reduced to the same level as when the engine is under partial load, making it possible to limit the vehicle speed to a predetermined speed or less, and to improve fuel efficiency.

In addition, this invention is provided with a variable bench yoke carburetor, a bypass valve control unit that controls the opening and closing of the bypass passage, and a solenoid valve that communicates or disconnects the chamber and second chamber with the atmosphere side. Since it is not connected to the throttle lever or throttle valve, and can limit the fuel supply amount and air supply amount with a mutually independent and simple configuration, it has a practical effect of being low cost and requiring no adjustment. .

[Brief explanation of the drawing]

The drawing shows one embodiment of this invention.
The figure is an overall configuration diagram of the vehicle speed limiting device, and FIG. 2 is an enlarged sectional view showing a bypass valve. 2...Intake passage, 4...Variable bench yoke carburetor, 5...Throttle valve, 6...Supercharger,
20... Bypass path, 22... Bypass valve, 38
... Solenoid valve, 40 ... Vehicle speed sensor, 1
4... Suction piston, 15... First spring, 18... Piston control diaphragm, 2
6... First spring, 28... Bypass valve control section, 30... Valve control diaphragm, 33... Second spring, 35... Upstream side (first chamber), 3
7...Downstream side (second chamber).

Claims (1)

[Scope of utility model registration request] An intake passage of an internal combustion engine mounted on a vehicle, a throttle valve provided in the intake passage, a supercharger provided downstream of the throttle valve in the intake passage, and a throttle valve provided upstream of the intake passage A chamber separated from the intake passage by a sliding piston part and a piston control diaphragm connected to the piston part to proportionally control the intake area of the intake passage and the nozzle opening area for fuel supply, and the piston part. a first spring that biases the suction area and the nozzle opening area in a direction to decrease, and the piston control is moved by negative pressure generated by the intake flow passing through the intake passage upstream of the throttle valve. A variable bench yoke carburetor that moves the piston part in a direction in which the suction area and nozzle opening area increase in conjunction with the diaphragm, and is provided in parallel with the intake passage and communicates between the inlet side and the outlet side of the supercharger. a bypass passage provided in the bypass passage to open and close the bypass passage; a first chamber communicating with the intake passage between the turbocharger and the throttle valve; and a first chamber downstream of the turbocharger. A valve control diaphragm that partitions a second chamber communicating with the intake passage, the first chamber, and the second chamber and is connected to the bypass valve, and a second chamber that biases the bypass valve in the opening direction.
a bypass valve control unit comprising a spring; a solenoid valve that communicates or disconnects the chamber of the variable bench yuri carburetor and the second chamber of the bypass valve control unit with the atmosphere side; and detects the vehicle speed of the vehicle. a control relay that drives the solenoid valve according to a signal from the vehicle speed sensor, and when the vehicle speed detected by the vehicle speed sensor is equal to or higher than a predetermined value, the relay drives the solenoid valve to The chamber is communicated with the atmosphere side, and the piston portion is moved in the direction in which the suction area and the nozzle opening area are reduced, and the second chamber is communicated with the atmosphere side, and the bypass valve is moved in the opening direction. vehicle speed limiter.