JPH0335854Y2 - - Google Patents

Description

[Detailed Description of the Invention] (Industrial Application Field) This invention relates to an engine supercharging device equipped with a so-called mechanical supercharger, which is driven by the output shaft of the engine.

(Prior Art) In an engine equipped with a mechanical supercharger driven by the output shaft of the engine, although the engine output increases due to the drive of the supercharger, fuel consumption decreases and becomes uneconomical.

Therefore, drivers can drive or stop the turbocharger according to their own preferences, such as driving the turbocharger when they want to increase output and stopping the turbocharger when they want to improve fuel efficiency. It would be extremely convenient in practice if you could choose.

Conventionally, there is a known technology in which a mechanical supercharger and the output shaft of an engine are connected intermittently with a clutch, making it possible to drive and stop the supercharger while the engine is running (Japanese Patent Application Laid-Open No. (Refer to Japanese Patent No. 59-30414), this technology does not allow the driver to engage and disengage the clutch according to his/her own selection as described above.

By the way, if the clutch is made to be engaged and engaged by the driver's own choice as described above, if the clutch is engaged when the engine speed is high, a large load will suddenly be applied to the supercharger, which may damage the supercharger. There is.

(Purpose of the invention) This invention was made in view of the above problems.
The driver can engage and disengage the clutch according to his/her own selection, allowing him/her to select high output and economy.In addition, the engine protects the supercharger by preventing the clutch from engaging in the high speed range of the engine. The purpose is to provide a supercharging device.

(Structure of the invention) The structure of this invention for achieving the above object is shown in FIG.

In FIG. 1, a supercharger 13 is provided in an intake passage 12 connected to an engine main body 11, and this supercharger 13 is connected to an output shaft 15 of the engine main body 11 via a clutch 14. ing.
As a result, the supercharger 13 is driven by the output shaft 15, and the driving force is intermittent by the clutch 14.

Reference numeral 16 indicates engine rotation speed detection means, and reference numeral 17 indicates a manual switch that connects and disconnects the clutch 14 by manual switching operation.
The connected state of the clutch 14 is generated on condition that the ON operation is performed and the operating state of the engine is at least outside the deceleration region.
18 is a protection control means, and this protection control means 1
Reference numeral 8 receives the output of the rotational speed detection means 16, and disables switching of the manual switch 17 to the clutch connection side in a high rotational range above a predetermined rotational speed.

By operating the manual switch 17, the clutch 14 can be engaged or engaged according to the driver's own selection. Further, the protection control means 18 prevents clutch engagement in a high rotation range. In addition,
In a medium rotation region below the predetermined rotation speed and in a region smaller than the predetermined load, the protection control means 18
The disabling of the switching of the manual switch 17 to the clutch connection side performed by the above is canceled, and the connected state of the clutch 14 is generated on the condition that the manual switch 17 is turned on. As a result, when the supercharger 13 does not operate even though the manual switch 17 is turned on to request operation of the supercharger 13 in a high rotation range, the accelerator pedal is momentarily released to reduce the load. By reducing the operating state of the engine to less than a predetermined load (this accelerator operation also reduces the rotational speed), it becomes possible to immediately establish the engaged state of the clutch 14.

(Example) Hereinafter, an example of this invention will be described with reference to the drawings.

FIG. 2 shows a so-called partially supercharged engine. In this figure, an air flow meter 22 is provided downstream of the air cleaner 21 in the intake passage 12, and downstream of the air flow meter 22, the intake passage 12 branches into a main intake passage 12a and a supercharging passage 12b. The above main intake passage 12a
is provided with a throttle valve 24, a pressure sensor 25 for detecting intake negative pressure, and a fuel injection valve 26, and the supercharging passage 12b is provided with a supercharger 13 consisting of a vane type air pump, and a supercharging passage opening/closing valve. A valve 27 is provided.

Moreover, the supercharger 13 in the supercharging passage 12b
A relief passage 28 is provided between the upstream side and the downstream side of the engine, and a supercharging relief valve 29 is inserted into this relief passage 28 to prevent supercharging pressure from becoming excessive.

The engine body 11 has two intake ports, namely, a main intake port 32 that is opened and closed by a main intake valve 31, and a supercharging port 34 that is opened only at the end of the intake stroke by a supercharging valve 33. The main intake port 32 is connected to the main intake passage 12a, and the supercharging port 34 is connected to the supercharging passage 12b. Therefore, supercharging occurs only at the end of the intake stroke. This is so-called partial supercharging.

The engine main body 11 has an exhaust port 36 that is opened and closed by an exhaust valve 35, and this exhaust port 36 is connected to an exhaust pipe 37. Further, the exhaust pipe 37 is equipped with a catalyst 38 for purifying exhaust gas.

The supercharger 13 is connected to an output shaft 15 of the engine body 11 via an electromagnetic clutch 14. Thereby, the supercharger 13 is connected to the output shaft 1
5, and the driving force is intermittent by the clutch 14.

Reference numeral 41 designates a microcomputer which outputs an air amount detection signal a from the air flow meter 22, a rotational speed detection signal b from the rotational speed detection means 16, and a switching signal c from the manual switch 17 that connects and disconnects the clutch 14 by manual switching operation. , and the intake pressure signal d from the pressure sensor 25 are input. The microcomputer 41 calculates the fuel injection amount based on the air amount detection signal a, outputs the fuel injection control signal e, and controls the fuel injection amount from the fuel injection valve 26.

Further, the microcomputer 41 outputs a clutch control signal f based on the rotation speed detection signal b, switching signal c, and intake pressure signal d using the built-in protection control means 18, and controls the clutch 14.
intermittent. Additionally, the clutch control signal f opens and closes the supercharging passage opening/closing valve 27 to close the supercharging passage 12b when the supercharger 13 is not driven, thereby increasing intake resistance due to intake air flowing into the supercharging passage 12b. is prevented.

Next, a method of controlling the clutch 14 using the microcomputer 41 will be explained.

First, an outline of this control method is shown in Figures 3 and 4.
This will be explained based on the diagram. The shaded area in FIG. 3 shows the operating area of the supercharger 13, and the shaded area in FIG. 4 shows the area where the clutch 14 is effectively switched to the connection side (ON side).

In FIG. 3, the horizontal axis is the rotation speed detection means 16
The vertical axis indicates the engine rotation speed detected by the pressure sensor 25 (see Fig. 2).
shows the intake pressure detected by and the corresponding engine load. When the rotation speed is lower than the reference rotation speed RPM ₀ and the intake pressure P detected by the pressure sensor 25 (see Figure 2) is the reference pressure P ₀ (P ₀ is in the range of -100 to -200 mmHg in this example). ), that is, the low rotation high load area A, and the high rotation area C, which is higher than the reference rotation speed RPM ₀ and excludes the deceleration area B. In these areas A and C, the clutch 14 in FIG. 2 is connected and the supercharger 1 is
3 to perform supercharging. Note that D in FIG. 3 indicates an idle area.

When supercharging is performed in regions A and C in FIG. 3 above, in the low rotation and high load region A, the rotation speed is low, so there is no problem even if the clutch 14 in FIG. 2 is switched to the connected state, but in the third region In the high rotation region C shown in the figure, if the clutch 14 shown in FIG.

Therefore, when the manual switch 17 is turned ON, that is, switched to the clutch connection side, only in the low rotation high load region A shown in FIG. 4 (same as the low rotation high load region A in FIG. 3) and the dead zone E, Clutch 1 in Figure 2
4 is connected, and the clutch 14 in FIG. 2 is controlled so as not to be connected in the low rotation/low load region F in FIG. 4 and the high rotation region G excluding the dead zone E mentioned above. In other words, in this high rotation region G, the manual switch 17 is
ON (switching to clutch connection side) is disabled. This control is performed by the clutch control signal f generated by the protection control means 18 built into the microcomputer 41 shown in FIG.

The details of the above control will be explained with reference to the flowchart of FIG. In the figure, P1 to P8 indicate each step of control.

Start with P1, and manual switch 17 with P2.
Determine whether it is ON (clutch connected) or not. If manual switch 17 is OFF (clutch disconnected), P
Proceed to step 3, turn the clutch 14 OFF (cut off state), and stop the supercharger 13 (Fig. 2). This operation is performed regardless of engine speed.

If manual switch 17 is ON, P2 to P
Proceed to step 4. In this P4, the rotation speed detection means 16
Engine speed RPM detected in (Figure 2)
and the above reference rotation speed RPM ₀ (for example 2000 ~
3000 rpm) is smaller than ε. When this difference is smaller than ε, that is, when the rotation speed RPM is in the dead zone E (FIG. 4), the process proceeds to P5 and the clutch 14 is turned ON.
When the difference is larger than ε, that is, outside the dead zone E, the process advances to P6.

In this P6, the rotation speed RPM and the reference rotation speed
The magnitude of RPM ₀ is compared. When the rotation speed RPM is smaller than the reference rotation speed RPM ₀ , the process advances to P7 and the intake pressure P is compared with the reference pressure P ₀ . When the intake pressure P is higher than the reference pressure _P0 , that is, when the load is high, it means that you are in the low rotation high load region A in FIG. 4, so proceed to P5 in FIG. Turn on and perform supercharging.

When the rotation speed RPM is larger than the reference rotation speed RPM ₀ at P6 above, that is, when it is in the high rotation region G of FIG. 4, the process proceeds to P8 of FIG. maintain. That is, switching the manual switch 17 to ON (clutch connection side) is disabled. This prevents excessive load from being applied to the supercharger 13 and damaging the supercharger 13. Further, the state in which the clutch 14 is disengaged can be canceled by the driver momentarily releasing the accelerator pedal (not shown). In other words, by releasing the accelerator pedal, the operating state of the engine shifts from the high rotation range G (see Figure 4) to the deceleration range B (see Figure 3), and then to the dead zone E in this deceleration range B. will be transferred. Therefore, as the operating state shifts to dead zone E (see Fig. 4), the process proceeds from P4 to P5 in Fig. 5, the clutch 14 is turned ON, and the operation of the supercharger 13 is started. Become. This makes it possible to satisfy the driver's acceleration request while ensuring the reliability of the supercharger 13.

This invention can be applied not only to the partial supercharging type described above, but also to a type that switches between full supercharging and no supercharging as shown in FIG.

In FIG. 6, a supercharging passage 12b is connected upstream of the throttle valve 24 in the intake passage 12, a supercharger 13 is attached to this supercharging passage 12b, and a connection between the intake passage 12 and the supercharging passage 12b is shown. A switching valve 51 is attached to the section. By opening and closing this switching valve 51, there is a case of full supercharging in which all of the intake air is sent into the engine main body 11 through the supercharger 13, and a non-supercharging case in which all of the intake air is sent into the engine main body 11 without passing through the supercharger. Switching is performed between supercharging and supercharging.

(Effects of the invention) As explained above, according to this invention, the driver selects between high output and economy by engaging and disengaging the clutch of the supercharger through the manual switch operation. This makes it extremely easy to use in practice.

Further, since the protection control means 18 prevents clutch engagement in a high rotation range, the supercharger is effectively protected. Further, in a load range smaller than a predetermined load in a medium rotation range, the control by the protection control means 18 is released and the clutch 14 is brought into a connected state on the condition that the manual switch 17 is turned on. This makes it possible for the driver to instantly start operating the turbocharger by releasing the accelerator pedal, ensuring reliability of the turbocharger by prohibiting clutch engagement in the above-mentioned high rotation range. It is possible to immediately satisfy the driver's acceleration request.

[Brief explanation of the drawing]

FIG. 1 is a schematic configuration diagram showing the configuration of this invention, FIG. 2 is a schematic configuration diagram showing an embodiment of this invention, and FIG. 3 is a characteristic diagram showing the supercharging region in the same embodiment.
FIG. 4 is a characteristic diagram showing the switching range of the clutch in the same embodiment, FIG. 5 is a flowchart for explaining the operation of the same embodiment, and FIG. 6 is a schematic configuration diagram showing another embodiment. 11...Engine body, 12...Intake passage, 1
3...Supercharger, 14...Clutch, 15...Output shaft, 16...Rotation speed detection means, 17...Manual switch, 18...Protection control means, B...Deceleration area,
G...High rotation area, E...Dead zone.

Claims (1)

[Claims for Utility Model Registration] A supercharger provided in the intake passage and driven by the output shaft of the engine; a clutch provided between the supercharger and the output shaft for intermittent driving force; A manual switch that connects and disconnects the clutch by manual switching operation, and a clutch that generates a connected state of the clutch on condition that the manual switch is turned on and the engine operating state is at least outside the deceleration region. a control means; an engine rotation speed detection means; a protection control means that receives the output of the rotation speed detection means and disables switching of the manual switch to the clutch connection side in a high rotation range above a predetermined rotation speed; further comprising: load detection means for detecting an engine load; and a signal receiving means from the load detection means and the engine rotation speed detection means, the engine rotation speed is in a medium rotation range below the predetermined rotation speed, and the engine When the load is in a load range smaller than a predetermined load, the control for disabling the switching of the manual switch to the clutch connection side performed by the protection control means is canceled, and the manual switch is turned on. A supercharging device for an engine, comprising: protection release control means for generating a connected state of the clutch on the condition that the clutch is in a connected state.