JPS61223234A - Supercharge pressure controlling structure in internal-combustion engine equipped with supercharger - Google Patents

Abstract

PURPOSE:To simplify the structure by constituting an interlocking means from a cam and two cam followers engaged with each valve, in the constitution in which a control valve installed into a bypass passage which makes a detour around a supercharger and a throttle valve are interlocked with a throttle pedal through an interlocking means. CONSTITUTION:A vane pump 5 as supercharger, intercooler 7, surge tank 8, carburetor 9, throttle valve 18, etc. are installed midway into an intake conduit 3. Further, a bypass passage 20 for connecting the conduit 3 set between the vane pump 5 and an inlet chamber 4 and the surge tank 8 is provided, making a detour around the vane pump 5, and a control valve 19 is installed into the passage 20. The throttle valve 18 and the control valve 19 are interlocked by an interlocking means consisting of a cam 22 which turns according to the stepping-in quantity of a throttle pedal and the cam followers 25 and 28 which are attached onto the cam 22 and formed integrally with the discs 24 and 27 fixed onto the valve shafts 23 and 26 of the throttle valve 18 and the control valve 19, respectively.

Description

DETAILED DESCRIPTION OF THE INVENTION <Industrial Application Field> The present invention relates to a supercharging pressure control structure for a supercharged internal combustion mtm.

<Conventional technology> By pressurizing the intake air supplied to the combustion chamber of the engine, it is possible to increase the specific weight of the mixed/metallic air, increase its packing density, and increase the output of the engine. It has been put into practical use in various ways. As a means for pressurizing intake air, in addition to centrifugal and axial flow compressors, a cylinder type compressor is also used. To drive such a compressor, a turbine driven by exhaust gas is used, or the output of the engine is used directly.

When a mechanical compressor such as a vane pump is used as a supercharger to compress intake air, the supercharger is constantly driven by the engine, but supercharging may be necessary depending on the engine load condition. In fact, this has the disadvantage of unnecessarily increasing the load on the engine and worsening fuel efficiency. Therefore, by installing an electromagnetic clutch on the input shaft of the supercharger □ and disconnecting the clutch as necessary, or by connecting the front and rear of the supercharger with a bypass passage and opening and closing the passage with a control valve, It is known to reduce the torque required to drive a supercharger, if necessary, to reduce unnecessary loads on the engine.

When using a bypass passage to reduce the pump load on the supercharger when supercharging pressure is not required, the timing of opening and closing of the control valve becomes an issue. Utility Model Publication No. 58-6921 and Japanese Patent Application Publication No. 1977
8-101218.

A structure has been proposed in which the control valve is activated by detecting the rotational speed or boost pressure of the engine. However, when it comes to vehicle engines, there is a tendency for drivers to expect the engine to produce output that corresponds to the stroke of the throttle pedal. Controlling the boost pressure is not preferable from the viewpoint of engine responsiveness.

By the way, the throttle valve opening and accelerator pedal stroke are 0-
In consideration of elongation of the accelerator wire over time, adjustment errors, etc., the throttle valve is set to be fully open before the accelerator pedal reaches the end of zero stroke. Therefore, for the amount of depression of the accelerator pedal,
This has the drawback of giving the driver the impression that the engine output has reached a plateau before the end of the pedal stroke.

(Problems to be Solved by the Invention) In view of these drawbacks of the prior art, the main object of the present invention is to improve the responsiveness of the engine so that the engine output increases in accordance with the depression stroke of the throttle pedal. The object of the present invention is to provide a supercharging pressure 5III structure in a supercharged internal combustion engine.

The second purpose of this design is to develop the above-mentioned system so that the engine's output increases smoothly as the throttle pedal is depressed, and even after the throttle valve is fully opened, the engine's output increases even more. The object of the present invention is to provide a supercharging pressure control structure.

<Means for Solving the Problems> According to the present invention, such an object is achieved by:
A supercharger connected to the upstream side thereof, a bypass passage communicating the discharge side and suction side of the supercharger, a control valve for opening and closing the bypass passage, the throttle valve and the control valve. A supercharging pressure control structure in a supercharged internal combustion engine comprising an interlocking means interlocked with a throttle pedal,
The 111 hand ffl includes a cam fixed to a pedal shaft that rotates in accordance with the depression stroke of the throttle pedal, and a first cam follower that determines the opening degree of the throttle valve by coming into contact with and following the cam. This is achieved by providing a supercharging pressure control structure characterized in that it includes a second cam follower that determines the opening degree of the control valve by coming into contact with and following the cam.

<Function> In this way, if the opening degrees of the control valve and the throttle valve are controlled by the cam that responds to the stroke of the throttle pedal, the opening characteristics of each can be freely set, so that the throttle valve can be fully opened. Even after this occurs, the engine output can be smoothly increased in accordance with the depression stroke of the throttle pedal.

Embodiments The present invention will now be described in detail with reference to specific embodiments with reference to the accompanying drawings.

FIG. 1 shows a system diagram of the entire intake path of a supercharged internal combustion engine equipped with a supercharging pressure control structure according to the present invention.

Air cleaner case 1 having an opening open to the atmosphere
A filter paper-type filter element 2 is installed inside the device to purify the air that is taken in. The air purified here is guided to an inlet chamber 4 through a conduit 3 and sucked into a vane pump 5 as a supercharger.

The vane pump 5 includes a rotor 5a and vanes 5b that are driven by the crankshaft of the engine via a pulley and a belt.
The suction air is compressed and discharged by the movement of the suction air, but the suction flow rate periodically fluctuates, which generates pulsating noise. Therefore, the inlet chamber 4 acts to reduce this pulsating noise by defining an air pocket immediately before the pump suction port.

The intake air pressurized by the vane pump 5 generates pulsating noise on the discharge side as well as on the intake side, but this discharge pulsation is absorbed by rapidly expanding the pressurized air in the outlet chamber 6. There is.

The intake air compressed by the vane pump 5 has a relatively high temperature due to adiabatic changes, and has a relatively small specific weight because it is thermally expanded. However, in line with the purpose of the supercharger, which is to fill the cylinder with as much intake air as possible, it is desirable that the specific weight of the intake air be large, and excessively high temperature of the intake air may cause vaporization. This is harmful to the normal operation of the equipment, as well as to the engine and performance, as it makes knocking more likely to occur. Therefore, an intercooler 7 that cools the discharged air is disposed downstream of the discharge port of the vane pump 5.

This intercooler 7 includes a large number of flat tubes 72,
A radiator core 7 comprising full gate fins 73 connecting adjacent tubes 72 to each other.
The core 70 is installed so as to be located in a part of the engine room where outside air flows relatively, and the compressed and high temperature intake air passes through the tube 72. Accordingly, the heat is dissipated from the surface of the full gate fin 73 into the outside air passing through the core 7o.

The intake air cooled by the intercooler 7 is then sent into the surge tank 8 from the upper part of the tank, but the discharge pulsation that still remains at this time is caused by the discharge pulsation generated in the engine 13 at the intake port of the carburetor 9. The suction pulsation caused by the reciprocating movement of the piston 10 is further attenuated by the volume of the surge tank 8. The surge tank 8 is also provided with a relief valve 11 as a pressure regulating valve, and the pressure inside the surge tank 8 exceeds a value set by the spring force of the coil spring 11b that opens the relief valve element 11a. As it rises,
This allows excess air to escape and prevents the boost pressure from rising excessively.

The intake and outlet ports of the above-mentioned surge tank 8 are arranged vertically with height differences, and the intake air sent from above is located below the tank and is connected almost directly to the intake port of the vaporizer. Air is sent to the suction passage 9a of the carburetor 9 from the suction outlet. Because the intake and inlet ports are arranged with a difference in height between the top and bottom, even if blowback occurs from the carburetor, the fuel will stay at the bottom of the surge tank 8 due to gravity, and will reach the supercharger. Fuel is prevented from reaching the fuel.

The intake air pressure-fed to the carburetor 9 in this way is finally mixed with fuel in the carburetor B9 and the intake manifold 12, and is sent to the combustion chamber 15 in the upper part of the cylinder according to the movement of the intake valve 14 of the engine 13.・Caught in. Naturally, the gases after combustion are discharged into the exhaust manifold 17 by the movement of the exhaust valve 16 and the piston 10.

In this way, in the case of a supercharger that is operated by the driving power of the engine's crankshaft, it constantly compresses the intake air, and supercharging is performed even when the throttle valve 18 is closed, especially at low loads. This has the disadvantage that the pump load worsens fuel efficiency. Therefore, throttle valve 1
The surge tank 8 is configured to bypass the supercharger 5 with a bypass passage 20 having a control valve 19 interlocked with the surge tank 8.
and the conduit 3 are connected. In this way, when the engine is under low load and the throttle valve 18 is generally closed, the control valve 19 is opened and the surge tank 8 and 1i13 are communicated through the bypass passage 20, thereby increasing the boost pressure. The pump is returned upstream from the feeder 5 to reduce the pump load at low load times.

Next, the r of control valve 19! The procedure for a111 will be explained.

Figure 2 shows the conventional method of interlocking the throttle valve and control valve with the throttle pedal, with the horizontal axis representing the stroke of the throttle pedal and the vertical axis representing the opening degrees of the throttle valve 18 and control valve 19. . The opening degree of the throttle valve 18 is approximately proportional to the stroke of the throttle pedal, but as described above, it is set to be fully open before the end of the pedal stroke. The opening degree of the control valve 19 decreases linearly according to the stroke of the throttle pedal.
It becomes fully open before the end of the throttle pedal.

Therefore, even if the driver does not press the throttle pedal that much, supercharging is still occurring to a certain extent, so even if the driver presses the throttle pedal to further increase output, especially at the end of the pedal stroke. In the vicinity, there was an inconvenience that the engine output did not increase as much as expected and the feeling of acceleration of the engine was impaired.

FIG. 3 is a graph similar to FIG. 2 showing the opening/closing procedure of the control valve according to the present invention. The throttle valve 18 increases linearly in accordance with the depression stroke of the throttle pedal, but as in the conventional example, it becomes fully open at a position S1 somewhat before the end of the stroke. On the other hand, the control valve 19 remains fully open at the beginning of the stroke of the throttle pedal, and when the stroke reaches a value S2 or more, it gradually opens in a linear manner as the stroke increases.

The opening degree of the control valve 19 continues to decrease linearly as the pedal stroke increases, even beyond the stroke S when the throttle valve 18 is fully opened. The control valve 19 enters the fully closed state only when this point is reached.

Therefore, according to the control valve opening/closing procedure according to the present invention, supercharging is not performed at the beginning of the stroke of the accelerator pedal, and supercharging is performed only when the opening of the throttle valve becomes large enough to゛The engine output is increased smoothly. In addition, since the fully open state of the throttle valve and the fully open state of the control valve are realized one after the other as the stroke of the throttle pedal increases,
Especially when the engine is generating high output, the response to the pedal becomes extremely smooth.

FIGS. 4 to 7 show an example of a configuration for realizing the control valve and the throttle valve according to the present invention as described above, with respect to the stroke of the throttle pedal.

An oval cam 22 consisting of a circular portion 22a and a bulging portion 22b is fixed to a pedal shaft 21 which rotates directly in accordance with the movement of the throttle pedal.

The circular portion 22a is approximately 180' centered on the pedal shaft 21.
The throttle shaft 23 does not necessarily have to be directly connected to the valve shaft of the throttle shaft 18, but its rotation angle corresponds to the opening degree of the throttle valve 18. A disk 24 is fixed to the shaft 23,
A cam follower 25, which may consist of a roller engageable with the cam 22, is attached to the outer periphery of the disc. Although the control shaft 26 does not necessarily need to be directly connected to the valve shaft of the control valve 19, its rotation angle corresponds to the opening degree of the control valve 19. A disc 27 is fixed to the control shaft 26, and a cam follower 28, which may be a 0-roller that can engage with the cam 22, is attached to the outer periphery of the disc 27.

FIG. 4 shows a state in which the stroke of the throttle pedal is zero, and the cam follower 25 of the throttle shaft 23 is in contact with the bulging portion 22b of the cam 22, and the cam follower 28 on the control shaft 26 side is in contact with the circular portion of the cam 22. It is in contact with 22a. Until the cam 22 rotates approximately 45 degrees from this position and reaches the position shown in FIG. The cam follower 25 on the side of the throttle shaft 23 does not rotate at all, while the cam follower 25 on the side of the throttle shaft 23
2b, and the rotation angle of the throttle shaft 23 and the rotation angle of the cam 22, that is, the camshaft 21, are approximately proportional. When the cam 22 rotates further, the cam follower 28 on the side of the control shaft 26 starts to come into contact with the bulging portion 22b of the cam 22, so that the rotation angle of the control shaft 26 and the rotation angle of the pedal shaft 21 are approximately proportional. . However, in this case, the rotation direction of the control valve 26 is the direction in which the control valve 19 is closed.

When the cam 22 rotates further, as shown in FIG.
The cam follower 25 on the side of the throttle shaft 23 reaches the circular portion 22a of the cam 22, and the throttle shaft 23 no longer rotates. When the throttle shaft 23 is in such an angular position, the throttle valve 18 is fully open. During this time, the control axis 1p. It rotates substantially proportionally to the pedal shaft 21 and gradually closes the Ill'1B valve 19.

FIG. 7 shows a state in which the stroke of the throttle pedal has reached its end, and the throttle shaft 23 is in a position corresponding to the fully open state of the throttle valve, and the control shaft 26 has its cam follower 28 positioned at the bulge of the cam 22. 22b has been reached, and this position corresponds to the full state of the control valve.

Although the present invention has been described above with reference to specific embodiments, the present invention is not limited to the above. In fact, the advantage of the present invention is that the opening degree changes of the throttle valve 18 and W4I11 valve 19 relative to the throttle opening of the throttle pedal can be freely set, and this can be done according to the characteristics of the engine, supercharger, etc. used, or the desired Depending on the engine response characteristics, the cam profile can be changed in various ways, the closing or starting point of the control valve and/or throttle valve can be changed, and the opening change relative to the pedal stroke can be made curved to suit various customer needs. The present invention can be implemented using the following methods.

<Effects of the Invention> As described above, since the present invention can be implemented with an extremely simple mechanical configuration, the manufacturing cost is low, the reliability is high, and the acceleration performance of the engine is suitably improved. The effect is extremely large because it can improve fuel efficiency and improve fuel efficiency at the same time.

[Brief explanation of the drawing]

FIG. 1 is an intake path system diagram of an engine having a supercharging pressure III structure according to the present invention. FIG. 2 is a graph showing changes in the opening degrees of the <I control valve and throttle valve with respect to the stroke of the throttle pedal, based on the prior art. FIG. 3 is a graph showing changes in the opening degrees of the control valve and throttle valve according to the present invention with respect to the stroke of the throttle pedal. FIGS. 4 to 7 are explanatory diagrams showing the structure of the control valve and throttle valve shown in FIG. 3 to realize the *m principle, and the operation thereof. 1... Air cleaner case 2... Filter element 3... Conduit 4... Inlet chamber 5... Vane pump 6... ν Outlet chamber 7... Intercooler 8... Surge tank 9.
... Carburetor 10 ... Piston 11 - ... Relief valve 12 ... Intake manifold 13 ... Engine 14 ... Intake valve 15 ... Combustion chamber
16... Exhaust valve 17... Exhaust manifold 18... Throttle valve 19... Control valve 20...
Bypass passage 21...Pedal shaft 22...Cam
22a...Circular part 22b...Bulging part 2
3... Throttle shaft 24... Disc 25.
...Cam follower 26...Control axis 27...
Disc 28...Cam follower 70...Core 72...
・Tube 73...Full gate fin patent
Applicant: Honda Motor Co., Ltd. Representative
Person Patent Attorney Kei Oshima - Part 2
Fig. Petarirestro-7 Fig. 3 80 Nurusu H-ko 7 Fig. 4 Fig. 6 Fig. 5 of O Fig. 7

Claims (1)

[Scope of Claims] A throttle valve, a supercharger connected to the upstream side of the throttle valve, a bypass passage that communicates the discharge side and suction side of the supercharger,
A supercharging pressure control structure in a supercharged internal combustion engine, comprising a control valve for opening and closing the bypass passage, and interlocking means for interlocking the throttle valve and the control valve with a throttle pedal, the interlocking means for interlocking the throttle valve and the control valve with a throttle pedal. the means is a cam fixed to a pedal shaft that rotates in response to a depression stroke of the throttle pedal;
A first cam follower that contacts and follows the cam to determine the opening of the throttle valve; and a second cam follower that contacts and follows the cam to determine the opening of the control valve. Features a boost pressure control structure.