JP2607030Y2 - Apparatus for preventing decrease in engine speed during vehicle shifting - Google Patents

Description

[Detailed description of the invention]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for preventing a decrease in engine speed during shifting of a vehicle having a throttle valve interlocked with an accelerator pedal.

[0002]

2. Description of the Related Art In a vehicle having an engine equipped with a throttle valve in an intake system and a manual transmission, when a clutch pedal is depressed and an accelerator pedal is released to shift a shift lever to a neutral position during upshifting, FIGS. When the throttle valve closes as shown in Fig. 4, that is, when the throttle opening is close to 0, the negative pressure of the intake manifold increases and the engine friction rapidly increases, so the engine speed decreases in a shorter time compared to an engine without a throttle valve. It is known to do.

In a transmission with a synchronizing device, a gear shift can be performed even if the gear of the next gear and the engine speed do not match. Therefore, referring to FIG. When the clutch is engaged, the engine speed drops from A to B, and the vehicle speed is mismatched by D, and the engine speed is mismatched by B-C. There is a problem that the vehicle speed drops.

Japanese Unexamined Patent Application Publication No. 57-140549 discloses a fuel cut control device for performing fuel cut at the time of gear change, and Japanese Patent Publication No. 52-24612.
A technique relating to a carburetor that opens a servo valve at the time of a gear change and introduces air is disclosed. However, these are intended to prevent an increase in harmful exhaust gas due to an increase in the air-fuel ratio at the time of a gear change, but not to prevent a decrease in engine speed.

[0005]

In the present invention, the throttle valve is closed by releasing the accelerator pedal during the upshift operation, the engine brake is applied, and the engine speed is rapidly reduced. It is an object of the present invention to provide a device for preventing a decrease in engine speed during a shift of a vehicle, which prevents a shift shock from occurring at the time, and further cuts off fuel supply to a mixer to reduce fuel consumption.

[0006]

According to the present invention, a mixer and a throttle valve are interposed in an intake pipe connected to an intake manifold, and a fuel circuit in which a fuel cutoff valve is interposed is connected to the mixer. The valve is provided with an air bypass passage communicating from an upstream side of the mixer of the intake duct to an intake pipe on a downstream side of the throttle valve, wherein the air bypass passage is provided in the device for preventing a decrease in engine speed at the time of shifting of a vehicle linked with an accelerator pedal. An on-off valve is provided in the passage, and a control device connected to the vehicle speed sensor, the shift position sensor, and the accelerator position sensor for opening and closing the on-off valve is provided. The control device reads the shift position and determines whether the vehicle is accelerating. The average acceleration is read from the vehicle speed sensor to be detected for a certain period of time to judge whether the vehicle is accelerating or not. When the accelerator pedal is in the idle position, the fuel shut-off valve is closed and the air bypass on-off valve is opened. Has the function of closing the valve.

[0007]

According to the present invention, the air bypass passage is communicated from the upstream side of the mixer of the intake duct to the intake pipe downstream of the throttle valve, an on-off valve is provided, and the control device is fixed from the vehicle speed sensor. The average acceleration over time is read to determine whether the vehicle is accelerating, and if the neutral position of the shift position and the idle position of the accelerator pedal are detected, the open / close valve of the air bypass passage is opened and the fuel cutoff valve communicating with the mixer is closed. Since the upshift operation is performed during acceleration of the vehicle, it is determined that the upshift operation is an upshift operation based on the determination of acceleration for a certain period of time based on the signal of the vehicle speed sensor and the detection of the neutral position and the idle position. And since the air bypass passage opens and the fuel is shut off,
Even when the throttle valve is closed, fresh air is supplied from the upstream of the mixer to the intake pipe from the air bypass passage, thereby preventing a decrease in the engine speed. Therefore, even if the accelerator pedal is released by the shift-up operation and the transmission becomes neutral, an excessive decrease in the engine speed is prevented, and a shock at the time of clutch engagement is eliminated. At the same time, particularly in an engine using gaseous fuel, fuel consumption and exhaust gas emission are reduced by shutting off fuel supply to the mixer. When the vehicle is not accelerating, the shift lever is not in neutral and the accelerator pedal is not in the idle position, it does not operate, so during a downshift operation other than upshifting, fuel is not shut off to the mixer, and malfunction occurs. Absent.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings.

In FIG. 1, an exhaust manifold 2 is attached to an engine E, and an exhaust pipe 3 is provided in the exhaust manifold 2 with a catalyst 4 and a muffler 5 interposed therebetween. Further, an intake pipe 6 is provided in the intake manifold 1 with a throttle valve 7 and a mixer 8 interposed therebetween, and an air duct 9 is attached to the intake pipe 6.

The cylinder 10 is provided with a filling port 12 through a check valve 11, and the emergency shutoff valve 1 is provided from the side near the cylinder 10.
3, 14, primary pressure reducing valve 15, secondary pressure reducing valve 16, safety valve 1
The eighth, third pressure reducing valve 17 and the shutoff valve 19 are connected to the mixer 8 by the fuel circuit 22.

A fuel bypass valve 23 is interposed between the fuel circuit 22 downstream of the shut-off valve 19 and the intake pipe 6, and the secondary pressure reducing valve 16 and the tertiary pressure reducing valve 17 are connected to the air circuit 20 by an air duct. 9, the primary pressure reducing valve 15 is connected to the water circuits 15a, 1
5b and is cooled.

The fuel bypass valve 23 is connected to the control unit 21 by an electric circuit.

The intake duct 9 and the intake pipe 6 are bypassed by an air bypass passage 24, and an open / close valve 25 is interposed in the air bypass passage 24. Its on-off valve 2
Reference numeral 5 denotes an electric circuit connected to a control device 26. The control device 26 is connected to the shut-off valve 19 and an engine rotation sensor F, a vehicle speed sensor G, a shift position sensor H, and an accelerator position sensor J (not shown).

The operation of the control device will be described below with reference to FIG.

First, the shift position is read, and an average acceleration is read from the vehicle speed sensor G for detecting whether or not the vehicle is accelerating (steps S1 and S2). It is determined whether the acceleration is positive (step S3), and if YES, it is determined whether the acceleration is neutral (step S4). YE
If S, it is determined whether the accelerator position is idle and the vehicle speed is positive (steps S5, S6). Both are YE
If S, the fuel cutoff valve is energized and closed, and the air bypass on-off valve is opened (steps S7 and S8). Step S3
If NO in S6, the air bypass on-off valve is closed and the fuel cutoff valve is turned off to supply fuel (steps S10 and S10).
9).

That is, when the transmission becomes neutral with the accelerator pedal released during the gear shifting during acceleration,
The fuel is cut and the air bypass passage is opened to supply air and control to reduce engine friction.

Therefore, referring to FIGS. 3 and 4, the engine speed A has decreased from B to B in FIG. 7 in the prior art, but only decreases to C. For example, the engine speed A changes from the second speed to the third speed. It matches the number and the vehicle speed, so there is no shock when clutching.

There is no problem that the engine speed is slightly too fast during the clutch meeting.

[0019]

As described above, according to the present invention, the following excellent effects can be obtained. (A) When the accelerator is released by the shift-up operation and the transmission becomes neutral, an excessive decrease in the engine speed is prevented, and the shock at the time of clutch engagement is eliminated. (B) At the same time, the fuel to the mixer is shut off,
Exhaust gas emissions are reduced. (C) It operates only at the time of shift-up operation, does not operate at the time of other operations such as shift-down, and does not cause a problem due to fuel cutoff to the mixer.

[Brief description of the drawings]

FIG. 1 is an overall configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart of the control shown in FIG. 1;

FIG. 3 is a diagram showing the relationship between the engine speed and the vehicle speed when shifting from a second speed to a third speed.

FIG. 4 is a diagram showing the relationship between engine speed and engine friction.

FIG. 5 is a diagram showing the relationship between throttle opening and engine friction.

FIG. 6 is a diagram showing a relationship between an intake air amount and engine friction.

FIG. 7 is a diagram showing the relationship between the engine speed and the vehicle speed at the time of shifting from the second speed to the third speed in the prior art.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 ... Intake manifold 2 ... Exhaust manifold 6 ... Intake pipe 7 ... Throttle valve 8 ... Mixer 9 ... Intake duct 15 ... Primary pressure reducing valve 16 ... Secondary pressure reducing valve 17 ... Tertiary pressure reducing valve 19 ... Shutoff valve 24 ... Air bypass passage 25 on-off valve 26 ... control device

────────────────────────────────────────────────── ─── Continued on the front page (51) Int.Cl. ⁷ Identification code FI F02M 21/02 301 F02M 21/02 301N (72) Inventor Hiroshi Matsuda Nissan Diesel Kogyo Co., Ltd. (56) References JP-A-57-140549 (JP, A) JP-A-58-124053 (JP, A) JP-A-57-22640 (JP, U) JP-B-55-48186 (JP, B2) JP-B-60-32026 (JP, B2) JP-B-52-24612 (JP, B2) (58) Fields investigated (Int. Cl. ⁷ , DB name) F02D 29/00-29/06 F02D 41/00 -41/40 F02D 43/00-45/00 F02M 21/02-21/04

Claims (1)

(57) [Scope of request for utility model registration] 1. A mixer (8) and a throttle valve (7) are interposed in an intake pipe (6) connected to an intake manifold (1), and a fuel cutoff valve (19) is interposed in the mixer (8). The throttle valve (7) is connected from the upstream side of the mixer (8) of the intake duct (9) in the device for preventing a decrease in the engine speed at the time of shifting of the vehicle, which is interlocked with the accelerator pedal. An air bypass passage (24) communicating with the intake pipe (6) on the downstream side of the throttle valve (7); an on-off valve (25) provided in the air bypass passage (24);
The on-off valve (2) is connected to a vehicle speed sensor (G), a shift position sensor (H), and an accelerator position sensor (J).
5) A control device (26) for opening and closing the vehicle is provided. The control device (26) reads the shift position, reads the average acceleration for a certain period of time from a vehicle speed sensor (G) that detects whether the vehicle is accelerating, and performs acceleration. Is determined, the acceleration is detected, and when the shift lever is in the neutral position and the accelerator pedal is in the idle position, the fuel cutoff valve (1) is detected.
9) is closed and the air bypass on-off valve (25) is opened. When the vehicle is not accelerating, the shift lever is not in neutral and the accelerator pedal is not in the idle position, the fuel cutoff valve (19) is opened and the air bypass on-off valve (25) is opened. A device for preventing a decrease in engine speed during a shift of a vehicle, the device having a function of closing the engine.