JPS6375314A - Intake control device of engine - Google Patents

Abstract

PURPOSE:To attempt improvement of firing performance at the time of fast idling by executing control of engine revolutional number at the time of idling, using a pumping loss control means. CONSTITUTION:A throttle valve 11 is interposed in a common intake passage 7 and it executes load control. At each side on the front and the rear sides of a medium housing 4, communicating ports 15f and 15r are opened and they form a communicating passage 16 which communicates both ports to each other. A control valve 17 to execute pumping loss control is interposed in the communicating passage 16. A bypass valve 14 of a passage 13 which bypasses the throttle valve 11, the control valve 17, injectors 14f and 14r are used to execute revolutional number control at the time of idling. By this, effective compression ratio at the time of fast idling can be raised and firing performance can be improved.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine intake control device.

[Prior art] In an automatic cycle engine in which the engine load is controlled by a throttle valve, the intake air amount is normally throttled by the throttle valve and the intake stroke is operated with the intake pressure lower than atmospheric pressure, which reduces resistance loss. It is well known that a type of so-called pumping loss occurs. especially,
At low loads when the intake m is strongly throttled, the intake pressure is low (e.g. -0, 7kg/cm" gauge), and the pumping loss caused by this is estimated to account for about 30% of the total of various resistance losses. Therefore, if this pumping loss can be reduced, the fuel efficiency of the engine can be significantly improved.

Conventionally, as a method to reduce this pumping loss, when the engine is under low load, the intake valve is closed earlier than the bottom dead center of the intake stroke, thereby virtually eliminating the negative work after the intake valve closes. , a so-called early closing system of the intake valve that reduces pumping loss (for example, see Japanese Patent Publication No. 10573/1983. However, in this reference example, a throttle valve is not provided), or a main intake valve. A communication boat is provided independent of the boat and is closed later than the main intake boat, and a communication passage is provided for communicating between the communication boats of the plurality of cylinders,
At low loads, a portion of the intake air from the cylinder at the beginning of the compression stroke flows into other cylinders at the front stage of the intake stroke through the communication passage, thereby suppressing the negative pressure of the intake air and reducing pumping loss. So-called late closing method using communication between cylinders (for example, see Japanese Patent Application Laid-Open No. 172429/1983).
Alternatively, a reflux boat that closes later than the main intake boat is provided independently of the main intake boat, and a reflux passage is provided that communicates the reflux boat with the intake passage downstream of the throttle valve. By recirculating a portion of the intake air at the beginning of the compression stroke to the intake passage through this recirculation passage, the load is reduced, and as a result, for the same load, the throttle valve is lower than that of a normal intake system that does not have a recirculation passage. A so-called late closing method using recirculation has been proposed, which increases the opening degree to suppress the negative pressure of intake air and reduce pumping loss.

By the way, it is well known that when idling is performed when the engine is cold, so-called fast idling is performed in which the load and rotational speed are higher than during normal idling to promote warm-up. ing.

Even in engines equipped with pumping loss control means, in order to perform preferable fast idle operation, a bypass passage that bypasses a throttle valve is conventionally provided in the intake passage, and a bypass valve is also interposed in the bypass passage. When the engine is cold, the intake air amount is increased by opening the bypass valve to perform fast idle control, or when the engine is cold, the control valve is closed in a slow closing method using recirculation, which seems to be communication between cylinders. In the early closing method, by delaying the closing timing of the intake valve and stopping pumping loss control,
Proposals have been made to perform fast idle control to increase filling efficiency, or to combine both in hopes of producing a synergistic effect.

However, even when the two are combined, for example in the late closing method, if fast idle operation is performed with the control valve open, the ignition performance will be poor due to the low intake air compression pressure, and the bypass valve will be closed. Since the capacity has to be increased, there are problems such as deterioration of control accuracy and response.On the other hand, if fast idle operation is performed with the control valve closed, flammability will improve. However, on the other hand, pumping loss increases, fuel efficiency decreases, and since load correction is performed by a bypass valve, the distance to the combustion chamber or working chamber is long, resulting in poor response.

[Object of the Invention] The present invention provides an engine equipped with a pumping loss control means, which has good ignition performance during fast idle operation, high fuel efficiency, and high accuracy of fast idle control.
The purpose of the present invention is to provide an engine intake control device with good responsiveness.

[Structure of the Invention] In order to achieve the above object, the present invention performs load control using a throttle valve and is equipped with means for performing pumping loss control. The present invention provides an intake air control device for an engine, characterized in that it is provided with means for controlling the rotational speed of the engine at the time using the pumping loss control means.

[Effects of the Invention] According to the present invention, in an engine equipped with a pumping loss control means, the late closing method gradually opens the control valve from the fully open state as the engine warms up, while the early closing method gradually opens the control valve from the fully open state. Since the engine speed is controlled by gradually delaying the intake valve closing timing, during fast idle operation, the effective compression ratio increases, improving ignition performance and increasing the amount of intake air. Therefore, the bypass valve has a small capacity, improving control accuracy and responsiveness.

Furthermore, since the load is corrected by the control valve or intake valve close to the combustion chamber or the working chamber, responsiveness is improved.

In addition, in the late-closing method, the air-fuel mixture flows with the control valve half-open, so the flow velocity of the air-fuel mixture increases and fuel atomization and mixing are improved.

[Embodiment 1] Hereinafter, a first embodiment of the present invention will be described regarding a two-cylinder low-return piston engine equipped with a pumping loss control means of a late closing type using communication between cylinders.

As shown in FIG. 1, the rotary piston engine RE has rotors 2f, 2r inside casings If, lr.
It is made up of front and rear mountain cylinders F and R that make a planetary rotation movement around an eccentric shaft 3 and continuously repeat suction, compression, explosion, expansion, and exhaust. Front and rear working chambers 5f are provided on the front and rear side surfaces of the intermediate housing 4 forming the partition walls of F and Fl, respectively.

Front and rear intake boats 6r, 6r for supplying intake air to 5r are open.

And the above-mentioned front and rear working chambers 5 r, 5 r
A common intake passage 7 is provided to supply intake air to the air cleaners 8, 8, and 8.
An air flow meter 9 that detects the amount of intake air from moment to moment, and a throttle valve 11 that opens and closes in response to depression of an accelerator pedal (not shown) are interposed.

The common intake passage 7 includes a front branch intake passage 13f that communicates with the front intake boat 6f at a branch portion 12 slightly downstream of the throttle valve 11, and a rear intake boat 6r.
It is divided into a rear side branch intake passage 13r which communicates with the front side.

In the rear branch intake passages 13fS and 13r, front and rear injectors 14f and 14r for injecting fuel during intake are installed near the front and rear intake boats 6r and 6r, respectively, with injection ports slightly inclined downstream. Interventions are being made.

When performing idling operation when the engine is cold, in order to increase the amount of intake air a little and promote warm-up of the engine, the throttle valve 11 is bypassed and the common intake passage 7 is connected to the air flow meter 9 slightly downstream. position and branching part 1
Bypass passage 13 that communicates with a position slightly upstream of 2.
A bypass valve 14 in the form of a solenoid valve is provided in the bypass passage 13 to open and close it under duty control in accordance with the temperature of the cooling water. This bypass valve 14 operates at a temperature below which the engine RE
When the temperature is below a predetermined temperature (hereinafter referred to as low-temperature set temperature Tw) at which the engine RE is completely cold, the engine RE is fully opened. (referred to as the high temperature set temperature Tw), the opening is fully closed, and when the cooling water temperature is higher than Tw+ and lower than Twz, the opening degree changes linearly with the cooling water temperature.

By the way, in order to reduce pumping loss by a late closing system using communication between the cylinders, the rotation of the rotors 2f and 2r is measured from the front and rear intake boats 6f and (ir) on the front and rear sides of the intermediate housing 4, respectively. The front and rear communication boats 1!M, 15r are opened at a position slightly on the leading side when viewed from the direction, and a communication passage I6 that communicates both the front and rear communication boats 15r, 15r is opened at the intermediate position. It is formed to penetrate the housing 4 in its thickness direction.

A control valve 17 for opening and closing the communication passage 16 is interposed at an intermediate position of the communication passage 16 in order to perform pumping loss control. The opening degree is feedback-controlled via the control valve controller +iCR.

Next, the control valve control mechanism CR will be explained.

As shown in FIG. 4, the control valve 1 interposed in the communication passage 16
7 is provided with an actuator 20 consisting of a negative pressure responsive diaphragm device, and in order to introduce the negative pressure in the intake passage downstream of the throttle valve 11 into the pressure chamber 22 of the actuator 20, the pressure chamber 22 A negative pressure introduction passage 26 is provided that communicates the intake passage with the intake passage downstream of the throttle valve. This negative pressure introduction passage 26 is provided with a boost tank having an appropriate capacity in order to stably secure the negative pressure introduced into the pressure chamber 22 of the actuator 20 near the opening to the intake passage downstream of the throttle valve l1. A boost tank 27 is provided to maintain the negative pressure in the boost tank 27 at a predetermined value.
A regulator 28 is interposed near the negative pressure introduction type.

Then, from the boost tank 27, the actuator 2
A first solenoid valve 29 for opening and closing the negative pressure introduction passage 26 is interposed in the negative pressure introduction passage 26 at the 0 side position, and the first solenoid valve 29 also controls the actuator 20.
At the side position, an atmosphere introduction passage 31 communicating with the atmosphere is connected to the negative pressure introduction passage 26, and a second solenoid valve 3 for opening and closing the atmosphere introduction passage 31 is connected to the negative pressure introduction passage 26.
2 is interposed.

The first solenoid valve 29 and the second solenoid valve 32 are duty-controlled by a control circuit 19 composed of a microcomputer, and their opening degrees are freely adjusted. By duty-controlling the second solenoid valve 32, the pressure within the pressure chamber 22 of the actuator 20 is adjusted, and as a result, the control valve 17 is controlled via the link mechanism 33.
The opening degree can be adjusted freely.

The control circuit 19 includes a rotation speed sensor 34 (see FIG. 1).
The engine rotation speed N is detected by the intake air ff1Qa, which is detected by the air flow meter 9 (see Fig.
, the throttle opening TVθ detected by the throttle valve opening sensor 36 (see FIG. 1), the cooling water temperature Tw detected by the temperature sensor 37 (see FIG. 1), and the throttle opening detected by the control valve opening sensor 35. By controlling the control valve 17, the bypass valve 14, and both the front and rear injectors 14r and 14r using the control valve opening degree as input information, pumping loss control during warm-up and fast idle control during cold engine operation are achieved. However, in the present invention, since pumping loss control during warm-up is not the main object, a description thereof will be omitted here.

Hereinafter, a fast idle control method by the control circuit 19 will be explained based on the control flowchart shown in FIG.

As shown in FIG. 5, when the engine cold control is started, the coolant temperature Tw is first read into the control circuit 19 in step Sl.

Subsequently, in step S2, the bypass valve 14 is opened to increase the amount of intake air at a fast idle in order to promote warm-up of the engine RE. The opening degree of this bypass valve 14 is duty-controlled according to the cooling water temperature, and is set at a predetermined low-temperature side set temperature Tw (for example, 30°C).
Below, it is fully opened, while the predetermined high temperature side set temperature Tw,
Above, it is fully closed, and from Tw to Tw, it changes linearly with the cooling water temperature. Thereafter, the control proceeds to step S3 in order to control the opening degree of the control valve 17 so that the engine speed during fast idle operation does not follow a predetermined target value.

In step S3, in order to make the engine speed during fast idle operation match a predetermined target value (see FIGS. 7 and 9), a control valve opening target is set in advance for the cooling water temperature Tw. Worth it. is read. This is the target value for the control valve opening. is expressed as a -order scale with respect to the cooling water temperature, for example, as shown by the broken line G4 in FIG. 7 or the broken line G8 in FIG. 9, and these target values L0 are expressed as digital information, It is stored in the control circuit 19 in advance.

Incidentally, the operating region in which pumping loss control should be performed during warm-up operation is set as region (■) shown in Fig. 6. Therefore, during warm-up, idling operation is controlled by control valve 1.
7 is open, the target control valve opening degree faL. As shown by the broken line G4 in Fig. 7, when the engine is cold (Tw≦'rw+), the valve is O (valve closed), and when the engine is warmed up (T
w≧Tw,) is set to match the control valve opening target value (not shown) during pumping loss control during warm-up, and in the section TWl<Tw<Tw, these are set as a straight line. It is preferable to set it so that it is tied at . In this case, the amount of bypass air becomes as shown by the broken line G2 in FIG. Since it is approximately 1/2, the capacity of the bypass valve 14 can be reduced, so that control accuracy and responsiveness of the bypass valve 14 are improved, and ignition performance is improved. As a result of such fast idle control, the engine speed during fast idle operation follows the target value indicated by broken line G in FIG.

Furthermore, the operating region in which pumping loss should be carried out during warm-up operation is set as region (■) shown in FIG. 8, and therefore, during warm-up, idling operation is performed with the control valve 17 closed. In such a case, set the control valve opening target value. As shown in broken line G8 in Fig. 9, when the machine is cold (Tw
≦Twυ is set to 0 (valve closed), and from the time when the cooling water temperature Tw reaches the low temperature side set value Tw, it increases linearly with respect to the cooling water temperature Tw, and the control valve opening degree is set to 80, for example.
%, from about 2/3 of the journey until reaching the high temperature side set value Tw, it decreases linearly with respect to the cooling water temperature Tw again, and when the cooling water temperature reaches Twt, it returns to 0.
It is preferable to set the valve so that the valve is closed. In this case, the amount of bypass air becomes as shown by broken line G6 in FIG. 9, which is almost the same as the amount of bypass air shown by broken line G7 when fast idle control is performed with the control valve 17 closed in the conventional example. (i.e. bypass valve I
3 requires a small capacity), and by reducing pumping loss, it is possible to avoid improving fuel efficiency during fast idling. As a result of such fast idle control, the engine speed during fast idle operation follows the target value shown by the broken line GIG in FIG.

Subsequently, the control proceeds to step S4, where the control valve opening degree target value read in step S3 is determined. In light of this, the control valve 17 should be fully opened, and therefore duty control is not required (L, = l
OO), it is compared whether the control valve opening degree target value L0 is less than 100. As a result of comparison, L.

If ≧100 (No), the control valve 17 should be fully opened, so duty control becomes unnecessary, and the control proceeds to step S13 to fully open the control valve I7.

″Thus, in step S13, the second solenoid valve 32
is fully closed, and the first solenoid valve 29 is fully opened. As a result, the atmosphere introduction passage 31 for introducing atmospheric pressure into the pressure chamber 22 of the actuator 20 is closed, and the negative pressure in the boost tank 27 is completely introduced into the pressure chamber 22 through the negative pressure introduction passage 26. Therefore, the control valve 17 is fully opened via the link mechanism 33. Subsequently, in step S15, in order to determine whether the engine r(E has warmed up), it is compared whether the cooling water temperature Tw is smaller than a predetermined high temperature side set temperature Tw2, and Tw<Tw
If t (YES), the engine rtE continues the fast idle operation, so the control returns to step S1 and continues. On the other hand, Tw≧T We (N
O), the engine r(E has reached a warm-up state, so the control ends).

On the other hand, as a result of the comparison in step S4 above, L.

If <100 (YES), further control valve opening target value is set. In light of this, the control valve 17 should be fully closed, and therefore the control proceeds to step S5 to determine whether the duty control is in a region (LO=O) where no duty control is required.

In step S5, a control valve opening target value is determined. h<.

It is compared to see if it is greater than. As a result of comparison, Lo≦
If 0 (No), there is no need to perform duty control, and control proceeds to step S14 to fully close the control valve 17.
You can proceed to

Thus, in step S14, the first solenoid valve 29
is fully closed, and the second solenoid valve 32 is fully opened. As a result, the negative pressure introduction passage 26 that introduces negative pressure into the pressure chamber 22 of the actuator 20 is closed, and the atmosphere introduction passage 3! Since atmospheric pressure is completely introduced into the pressure chamber 22 through the link mechanism 33, the control valve 1
7 is fully closed. Subsequently, in step S15, the engine R
In order to determine whether the engine RE has warmed up, it is compared whether the cooling water temperature Tv is lower than a predetermined high-temperature set temperature Twz, and if Tw<T++, (YES), the engine RE is Since the fast idle operation is continued, control returns to step St and continues. On the other hand, if Tw≧Tlh (No), the engine RE has reached a warm-up state and the control ends.

On the other hand, as a result of the comparison in step S5 above, L.

If >0 (YES), set the control valve opening target value. has a value greater than 0 and less than 100, so the control goes to step S6 to duty-control the first solenoid valve 29 or the second solenoid valve 32 in order to adjust the opening degree of the control valve.
You can proceed to

In step S6, the control valve opening detected by the control valve opening sensor 35, which is a so-called control amount required to feedback control the control valve 17, is read.

Subsequently, in the next step S7, a control valve opening target value for the control valve opening of the control valve 17 is determined. Deviation ΔL=Lo
L (hereinafter referred to as control deviation ΔL) is calculated. Depending on the value of this control deviation ΔL, the control valve opening becomes the control valve opening target value. is substantially larger than the control valve 1 and therefore the control valve 1
7 should be controlled in the closing direction, or the control valve opening degree is the control valve opening target value. Therefore, the control valve 17 should be controlled in the opening direction, or the control deviation ΔL
Since the absolute value 1ΔLl of is sufficiently small, the control first proceeds to step S8 in order to determine whether duty control should not be performed and the control valve opening degree should be maintained at the current level in order to stabilize the control.

In step S8, if the control deviation ΔL is less than that, the control deviation Lmin(
>O or less, this is referred to as a limit deviation L min). As a result of comparison, ΔL>Lmin
If (YES), the control valve opening is set to the control valve opening target value. Since it is substantially smaller, control proceeds to step S9 to duty-control the control valve 17 in the opening direction.

In step S9, the second solenoid valve 32 is fully closed and the atmosphere introduction passage 31 is closed in order to duty-control the control valve 17 in the opening direction. Then, the first solenoid valve 29 has an absolute value 1ΔL of the control deviation ΔL shown in FIG. 1O.
At the polygonal line G I+ which sets the duty ratio of the first solenoid valve 29 or the second solenoid valve 32 relative to 1, it is opened in accordance with the duty ratio corresponding to the absolute value 1ΔL+ of the control deviation. As a result, a negative pressure corresponding to the opening degree of the first solenoid valve 29 is introduced from the boost tank 27 into the pressure chamber 22 of the actuator 20 through the negative pressure introduction passage 26, and the opening degree of the control valve 17 increases. Control valve opening target value. approach.

Thereafter, in step S15, depending on whether Tw is smaller than Tw, the control returns to step St, continues, or
or be terminated.

On the other hand, as a result of the comparison in step S8 above, ΔL≦Lm
If in (No), should the control valve 17 be further subjected to duty control in the closing direction, or should the control valve 1 be controlled so that the absolute value 1ΔL1 of the control deviation is less than or equal to the limit deviation L min?
In order to determine whether the opening degree of 7 should be maintained at the current tit, the control proceeds to step SlO.

In step SIO, it is compared whether the control deviation ΔL is smaller than -Lmin. As a result of comparison, ΔL<-Lm
If in (YES), the control valve opening is the control valve opening target value. Since it is substantially larger, the control proceeds to step Sll in order to duty-control the control valve 17 in the closing direction.

In step Sll, in order to duty-control the control valve 17 in the closing direction, the first solenoid valve 29 is fully closed and the negative pressure introduction passage 26 is closed. Then, the second solenoid valve 32 is opened according to the duty ratio corresponding to the absolute value 1ΔL1 of the control deviation at the broken line G11 shown in FIG. As a result, atmospheric pressure corresponding to the opening degree of the second solenoid valve 32 is introduced into the pressure chamber 22 of the actuator 20 through the atmospheric introduction passage 31, and the opening degree of the control valve 17 decreases to reach the control valve opening degree target. Worth it. approach.

Thereafter, depending on whether Tw is smaller than TW2 in step S15, control returns to step S1, continues, or ends, respectively.

On the other hand, as a result of the comparison in step S10 above, ΔL≧−
If Lmin (No), the absolute value of control deviation 1ΔL1
is less than the limit deviation Lmin (1ΔL1≦Lmin), and the control proceeds to step S12 in order to maintain the current opening degree of the control valve 17 in order to stabilize the control.

In step S12, the first solenoid valve 29 and the second solenoid valve 32 are fully closed, and both the negative pressure introduction passage 26 and the atmosphere introduction passage 3L are closed. Therefore, the pressure chamber 22 of the actuator 20 is in a sealed state, and the internal pressure is maintained and does not change.

Therefore, the actuator 20 is not displaced and the opening degree of the control valve 17 is maintained as it is. After that, in step S15, Tw
Depending on whether Tw is smaller than Tw, the control proceeds to step S, respectively.
Return to l, continue, or exit.

As described above, according to the first embodiment of the present invention, in an engine equipped with a pumping loss control means, it is possible to improve the ignition performance and fuel efficiency during fast idle operation, and to improve the accuracy and responsiveness of fast idle control. can. Furthermore, since the intake flow rate increases, atomization and mixing of the fuel can be improved.

Hereinafter, a second preferred embodiment of the present invention will be described regarding a reciprocating engine equipped with pumping loss control means of a late closing type using recirculation.

As shown in FIG. 2, when the intake valve 41 is opened, the reciprocating engine CE sucks the air-fuel mixture into the combustion chamber 45 formed by the cylinder 44 from the intake port 43 communicating with the intake passage 42. The air-fuel mixture compressed by the piston 46 is ignited and burned by the spark plug 17, and when the exhaust valve 48 is opened, the exhaust gas in the combustion chamber 45 is sent to the exhaust passage 5.
As a result, the piston 46 reciprocates within the cylinder 44 in the axial direction of the cylinder 44, and this reciprocating movement is converted into rotational movement of the crankshaft 53 via the connecting rod 52. The basic structure is such that the output is output from the engine CE.

In the intake passage 42, an air cleaner 54 is provided in order from the upstream.
, an air flow meter 55 that detects the amount of intake air from moment to moment;
An injector 57 for injecting fuel into intake air is provided near a throttle valve 56 that opens and closes in response to depression of an accelerator pedal (not shown) and the intake port 43.

When idling when the engine is cold, the amount of intake air is increased slightly to promote warm-up of the engine CE.
The intake passage 42 is provided with a bypass passage 58 that bypasses the throttle valve 56 and communicates a position slightly downstream of the air flow meter 55 with a position slightly downstream of the throttle valve 56. has almost the same specifications as the first embodiment, and is provided with a bypass valve 59 for opening and closing it.

By the way, in order to reduce pumping loss due to the delayed closing method using reflux, a reflux port 62 (the 11th (see figure) is opened, and the recirculation port 62 communicates with the intake passage 42 at a position slightly downstream of the throttle valve 56 via a recirculation passage 63. A rotary control valve 64 that opens and closes the recirculation passage 63 is interposed at a substantially intermediate position of the recirculation passage 63 in order to perform pumping loss control according to the operating state. By changing , the air passage cross-sectional area in the recirculation passage 63, that is, the opening degree of the control valve can be freely changed.

The control valve 64 has a control valve control mechanism C as in the first embodiment.
The opening degree is feedback-controlled by a control circuit 65 via C.

The control circuit 65 controls the intake air ffi Q a detected by the air flow meter 55, the throttle opening TVθ detected by the throttle valve opening sensor 67, the cooling water temperature Tw detected by the temperature sensor 68, and the rotation speed sensor 69. Bombing loss control and fast idle control are performed using the detected engine speed N and the control valve opening degree detected by the control valve opening degree sensor as human power information.

The configuration and operation of the control valve control mechanism CC and control circuit 65, which perform pumping loss control during warm-up and fast idle control during cold operation, are completely the same as those of the control valve control mechanism CR and control circuit 19, respectively, in the first embodiment. Therefore, their explanation will be omitted.

As described above, according to the present invention, even in a reciprocating engine CE that adopts such a late closing method using recirculation, ignition performance during fast idle operation, fuel efficiency, accuracy and responsiveness of fast idle control, and fuel atomization can be improved. , mixing can be improved.

Hereinafter, the third preferable reciprocating engine of the present invention having a pumping loss control means using an early closing method will be described.
An example will be explained.

As shown in FIG. 3, when the intake valve 71 is opened, the reciprocating engine CE2 sucks the air-fuel mixture from the intake boat 73 communicating with the intake passage 72 into the combustion chamber 75 formed by the cylinder 74. The air-fuel mixture compressed by the piston 76 is ignited and burned by the spark plug 77, and when the exhaust valve 78 is opened, the exhaust gas in the combustion chamber 75 is sent to the exhaust passage 8.
As a result, the piston 76 reciprocates in the axial direction of the cylinder 74 within the cylinder 74, and this reciprocating movement is converted into rotational movement of the crankshaft 83 via the connecting rod 82. The basic structure is such that the output is output from the engine CE2.

In the intake passage 72, an air cleaner 84 is installed in order from the upstream side.
, an air flow meter 85 that detects the amount of intake air from moment to moment;
A throttle valve 86 that opens and closes in response to depression of an accelerator pedal (not shown) is provided.

When performing idling operation when the engine is cold, in order to increase the amount of intake air a little and promote warming up of the engine CE2, the intake passage 72 is connected to the air flow meter 85 by bypassing the throttle valve 86 and connecting the air flow meter 85 slightly downstream. A bypass passage 89 is provided that communicates a position slightly downstream of the throttle valve 86 with a position slightly downstream of the throttle valve 86.
The specifications are almost the same as those of the first and second embodiments, and a bypass valve 9I is provided to open and close the valve.

The intake passage 72 is branched at a branch point downstream of the throttle valve 86 into a high-load intake passage 90 through which intake air passes only during high loads, and a low-load intake passage 92 through which intake air passes only under low loads. The above-mentioned switching between the two intake passages is performed by using a first shutter valve 87 provided in the high-load intake passage 90 and a second shutter valve 97 provided in the low-load intake passage 92 depending on the engine load. This is done by opening and closing nine control circuits via a link mechanism 98.

Incidentally, a low-load timing valve 96 is provided in the low-load intake passage 92 for controlling pumping loss by an early closing method during low-load conditions. The timing valve 96 is rotated in synchronization with the crankshaft 83 via a timing belt 93 that is placed between a first pulley 94 attached to the crankshaft 83 and a second pulley 95 attached to the timing valve 96. It has become. The closing timing of the timing valve 96 is set to be earlier than the closing timing of the intake valve 71 by a predetermined crank angle, and the magnitude of this advance angle is determined by the control circuit 99 via the control mechanism CB. It is now duty-controlled.

The high load intake passage 90 and the low load intake passage 92 are
Slightly upstream of the intake boat 73, the intake boat 73 is assembled again to form a single intake passage 72, and the intake boat 73 of the intake passage 72
An injector 88 for injecting fuel into intake air is interposed at a position slightly upstream of the intake air, with its injection port slightly inclined downstream.

The control circuit 99 includes the intake air filQa detected by the air flow meter 85 and the throttle opening TVO1 temperature sensor 1 detected by the throttle valve opening sensor 100.
Pumping loss control and fast idle control are performed using the cooling water temperature Tw detected by 01, the engine rotation speed N1 detected by rotation speed sensor 102, and the closing timing of timing valve 96 as input information.

The configuration and operation of the control mechanism CB and control circuit 99 that perform pumping loss control during warm-up and fast idle control during cold operation are the same as those of the control valve control mechanism CR and control circuit 19 in the first embodiment, respectively. Their explanation will be omitted. However, the operation of opening and closing the control valve 17 in the first embodiment should be replaced with an operation of changing the closing timing of the timing valve 96 in the third embodiment.

As described above, according to the present invention, even in the reciprocating engine CE2 that adopts the early closing method, the ignition performance during fast idle operation, fuel efficiency, accuracy and responsiveness of fast idle control, and fuel atomization and mixing are improved. can be improved.

[Brief explanation of the drawing]

FIG. 1 is a system configuration diagram of a two-cylinder low-return piston engine equipped with a pumping loss control means of a late-closing type using communication between cylinders, showing a first embodiment of the present invention. FIG. 2 is a system configuration diagram of a reciprocating engine equipped with pumping loss control means of a late closing type using recirculation, showing a second embodiment of the present invention. FIG. 3 is a system configuration diagram of a reciprocating engine equipped with early-closing pumping loss control means, showing a third embodiment of the present invention. FIG. 4 is a detailed system configuration diagram of the control valve control mechanism shown in FIG. 1 or 2. FIG. FIG. 5 is a flowchart showing a method of controlling the control circuit. FIG. 6 is a diagram showing an example of a region where pumping loss control should be performed, and FIG. 7 is a diagram showing a state of fast idle control when such pumping loss control is performed. FIG. 8 is a diagram showing another example of a region in which pumping loss control should be performed, and FIG. 9 is a diagram showing a state of fast idle control when such pumping loss control is performed. FIG. 1O is a diagram showing the duty ratio of the first solenoid valve or the second solenoid valve with respect to the absolute value of the control deviation. FIG. 11 is a diagram showing the valve timing of the intake and exhaust valves of the engine according to the second embodiment shown in FIG. RE...Rotary piston engine, CE...Control valve control mechanism, 11...Throttle valve, 16...Communication path, 17
...Control valve, 19...Control circuit, CE...Reciprocating engine (late closing), CC...Control valve control mechanism, 56...Throttle valve, 63...Recirculation passage, 64...
...Control valve, 65...Control circuit, CB2...Reciprocating engine (early closing), CB...Timing valve control mechanism, 86...Throttle valve, 96...Timing valve, 99... control circuit. Makoto 6 nl :9? -j 700th 9th leap

Claims (1)

[Claims] (1) In an engine that performs load control using a throttle valve and is equipped with a means for performing pumping loss control, the pumping loss control means performs pumping loss control in a predetermined operating range and controls the engine rotational speed during idling. 1. An engine intake control device, characterized in that it is provided with a means for controlling the intake air using the following methods.