JPS6119930A - Supercharger control device in internal-combustion engine - Google Patents

Abstract

PURPOSE:To eliminate shocks upon engagement of a clutch and as well to prevent the durability of the clutch from deteriorating, by setting the supercharging range in which the clutch is engaged, in a high rotational speed range upon extremely low temperature operation of an engine. CONSTITUTION:An operating condition detecting means 6 detects the amount Q of intake-air and the rotational speed N of an engine. Meanwhile a temperature detecting means 8 detects the temperature of cooling water and the temperature of lubrication oil, and judgement is made such that extremely low temperature operation should be taken when the temperature of water is below 0 deg.C or the temperature oil is below 0 deg.C. or when both are satisfied, and a setting value changing means 9 selects the set value of ratio of the intake-air amount and the rotational speed, which is larger than a normal value, thereby the range of a supercharger 60 in which a clutch operating means 7 is operated may be set to be narrower.

Description

DETAILED DESCRIPTION OF THE INVENTION Field of the Invention The present invention relates to a control device for a mechanical supercharger in an internal combustion engine.

In conventional internal combustion engines, there is a problem in that the viscosity of lubricating oil increases at extremely low temperatures such as 0° C. or lower, resulting in increased friction and large rotational resistance. This is particularly noticeable when a mechanical supercharger is installed, since the load of the supercharger is added to the engine friction.

(In addition, as a prior art of the present invention, for example, Utility Model Publication No. 47-3
See No. 7939. ) Problems to be Solved by the Invention The present invention has been made in view of the problems of the prior art, and aims to provide a configuration that can reduce the load caused by the supercharger when the engine is at an extremely low temperature. purpose.

Means for Solving the Problems According to the present invention, as shown in FIG. 1, in an internal combustion engine equipped with a mechanical supercharger 3 in the intake system 2 of the engine 1, A clutch means 5 disposed between the drive shaft and an operating state detecting means 6 for detecting the operating state of the engine.
, a clutch and clutch actuating means 7 that engages or disengages the clutch and clutch means 5 in accordance with the operating state signal from the operating state detecting means 6, a temperature detecting means 8 that detects the extremely low temperature condition of the engine, and a temperature detecting means 7 that A set value for changing the set operating condition under which the clutch actuating means 5 is switched between engagement and disengagement so that the supercharging region is compressed at extremely low temperatures in accordance with the engine temperature condition detected by the means 8. The changing means 9 provides a supercharger control device for an internal combustion engine.

The operating temperature detection means 8 detects the temperature condition of the engine 1, and changes the selected temperature at which the clutch 5 switches from engagement to disengagement so that the supercharging region at extremely low temperatures is reduced.

Therefore, the supercharger 3 is operated at higher rotation speeds when the temperature is extremely low.

Embodiment In FIG. 2, 10 is an engine body, which includes a cylinder block 11, a piston 12, and a connecting rod 1.
4, crankshaft 16, crank pin 18, oil pan 2
0. Cylinder hend 22, intake valve 24, exhaust valve 26, valve spring 28, camshaft 30, camshaft housing 3
Consists of first class components.

An intake boat 32 is formed within the cylinder head 22 and connected to a surge tank 36 via an intake pipe 34. 38
is a throttle valve, which is arranged within the intake pipe 40. The throttle valve 38 is connected to the accelerator pedal 4 via a link 42.
4.

An air flow meter 46 is provided upstream of the throttle valve 38, and an air cleaner 48 is located upstream thereof.

An exhaust boat 50 is formed within the cylinder head 22 and is connected to a catalytic converter 54 via an exhaust manifold 52.

In this embodiment, the internal combustion engine is a fuel injection type, and the intake pipe 3
4 is provided with a fuel injector 56. 58 is a distributor.

According to the present invention, a Roots pump 60 as a mechanical supercharger is connected to the intake pipe 40 downstream of the throttle valve 38. The roots pump 60 includes a housing 62 and a pair of cocoon-shaped rotors 64 within the housing 62. The pair of rotors 64 are provided with mutually meshing gears (not shown) on their rotation shafts 66 . Therefore, the rotor 64 rotates in the opposite direction while maintaining a slight gap with respect to the inner periphery of the housing 62. A clutch with a pulley 68 is provided on one rotating shaft 66 of the rotor 64, and a pulley portion of the clutch 68 is connected to a pulley 72 on the crankshaft 16 via a belt 70. The pulley-equipped clutch 68 is configured as shown in FIG.
6 and a bearing 68 on a sleeve 68-2 fixed to the housing 62.
A pulley portion 68-5 that engages with the belt 70 is formed on the solenoid holder 68-4.

The engagement member 68 is attached to the disc 68-1 via the elastic member 68-6.
-7 is attached, and the engaging member 68-7 faces the solenoid holder 68-4 with a slight gap. A frictional engagement surface is engaged between these surfaces. Once the solenoid 68' is disposed in the U-shaped recess in the solenoid holder and fixed to the sleeve 68-2 by a stay means (not shown), the engaging member 68 is engaged when the solenoid 68' is not energized.
-7 is pulled away from the solenoid holder 68-4 by the elastic member 68-6. When the solenoid 68' is energized, the engaging member 68-7 is moved to the solenoid holder 68-.
4, and the engine rotation from the pulley portion 68-5 is transmitted to the supercharger shaft 66.

In FIG. 2, 100 is a control circuit for the electromagnetic clutch 68,
An actuation signal to the clutch 68 is formed based on signals from the operating condition detection sensor and the engine temperature detection sensor. The control circuit 100 can be shared with a control circuit for engine air-fuel ratio control or ignition timing control. Of course, a dedicated control circuit may also be used. The operating condition sensor includes the aforementioned air flow meter 46 and the rotation speed sensor 102 provided on the distributor 58. The air flow meter 46 is configured as a potentiometer as shown in FIG. 4, and generates an analog signal depending on the position of the valve stem, that is, the intake air i1Q. On the other hand, the rotation speed sensor 102 is configured as a Hall element provided opposite to the magnet 104 on the distribution shaft 58' of the distributor 58, as shown in FIG. Outputs a pulse signal.

The control circuit 100 is constructed as shown in the block diagram of FIG. 4, and consists of a microcomputer system.

That is, Microprocessing Unisoto (MPU) 10
6. A read-only memory (ROM) 108 and a random access memory (RAM) 110 are connected to each other via a bus 112, and a bus 112 is connected to an input/output (Ilo) port 114.

116 is a clock pulse generator. The air flow meter 46 is connected to the I10 via an analog multiplexer (MPX) 117 and an analog-to-digital (A/D) converter 118.
The rotation speed sensor 102 is connected to the I10 port 114 via the molding circuit 120.

Further, the I10 boat 114 is connected to the base of a driving transistor 124 of the clutch 68 via a latch 122, and a driving solenoid 68' (FIG. 3) of the clutch 68 is located in the collector emitter circuit of the transistor 124. By the energization control of ', the clutch 68 can be engaged and released, in other words, the supercharging 160 can be switched between operating and stopping. In order to detect the temperature condition of the engine, in this embodiment, the cylinder block 1 of the engine is
a water temperature sensor 127 that measures the temperature of the cooling water in the oil pan 20; and an oil temperature sensor 1 that measures the oil level of the lubricating oil in the oil pan 20.
29 are provided. These temperature sensors 127°12
9 can be configured as a thermistor and is connected to an A/D converter 118 via an MPX 117 as shown in the block diagram of FIG.

The microcomputer can perform other engine controls other than supercharging control, such as air-fuel ratio control and ignition timing control, and for this reason various sensors and actuators are connected to the I10 boat 114, but this is not the main function. Since it is not directly related to the features of the invention, illustration and description will be omitted.

The ROM 108 stores a program for controlling the clutch 68 and other programs for controlling engine operation. The program will be explained below, focusing only on the parts related to the present invention.

FIG. 5 shows the program flow of the main routine, in which various processes that require high speed are performed. When the program is started in step 200, initialization is performed in 202, and the MP
II 106 registers, RAM110, I10
Initial settings for the boat 114 are performed.

At 204, the liver υ106 converts the A/D conversion command of the intake air 1i signal from the air flow meter 46 to the A/D converter 118.
The digital signal corresponding to the intake air amount Q is J? A.M.
1100 is stored at a predetermined address. In the next step 206, a digital signal representing the rotation speed N from the rotation speed sensor 102 is input and stored at a predetermined address in the RAM 110. In step 208, the ratio of the rotational speed N to the intake air amount Q is calculated and stored in the RAM 110.

It is well known that Q/N is a value equivalent to the engine load. The program then proceeds to steps 210 and below,
Various processes for other controls in the main routine (
For example, feedback processing in air-fuel ratio control) is performed, and the calculation results of Q, N, and Q/H are used as appropriate.

FIG. 6 shows a program for controlling the supercharger, and in this embodiment, it is a time interrupt routine that is executed every predetermined time (for example, 8IIIS). Every time a predetermined time elapses, an interrupt request is received at the interrupt port of MP[I 106, and the routine starts executing at 290. At step 291, the MPU 106 receives MPX 1 from the I10 port 114.
At step 17, a command is issued to fetch data on the cold water temperature Tw from the water temperature sensor 127, and it is determined whether the value is lower than a predetermined value, for example, 0°C. In the next step 292, data on the lubricating oil temperature Toil is taken in from the oil temperature sensor 129, and it is determined whether the value is lower than a predetermined value, for example, 0°C. If the determination is No in both 291 and 292, it is determined that normal operation is being performed, and the process proceeds to 294. In 294, supercharger 60
A set value a of the rotation speed N, which is the switching point between operation and stop of the
Set the intake air amount to rotation speed ratio to No. and qo, respectively.
(Figure 7 (a)). Next the program is 302
Proceed to 302, I? The rotation speed data stored in the N area of AM 110 is set to the predetermined value a=No (Fig. 7 (A)).
), then at 304 RAM 11
It is determined whether the data of the ratio of the intake air amount G to the rotational speed N stored in the Q/N area of 0 is greater than b=qo. As is clear from the supercharger operation map in Figure 7 (a), 302 is No (N<a), and 304 is also No.
The operating range where (Q/N < b) is the supercharger stop range, in which case the program proceeds to 306.

MPU 106 launches 122 from I10 port 114
Apply a reset signal to. Therefore, transistor 12
4 becomes the cut-off, and the solenoid 68 of the clutch 68
' is demagnetized and the clutch 68 is released.

Therefore, the rotation of the crankshaft 16 is not transmitted to the rotor 64 of the supercharger 60. The rotor 64 merely idles due to the flow of air from the throttle valve 38 toward the surge tank 36, and no supercharging is performed.

Yes (N > a) at 302 in Figure 6 or 302
, No (N < a), but 304, Yes (Q/N > b
) is the operating range of the supercharger, and the program is 30
8, the MPu 106 applies a set signal to the latch 122 from the I10 port 114. Therefore, the transistor 124 is turned on, and the solenoid 6 of the clutch 68
8' is energized, so the clutch 68 is engaged. As a result, the rotation of the engine crankshaft 16 is controlled by the pulley 72,
The rotation shaft 66 of the supercharger 60 via the belt 70 and pulley 68
, the pair of gluders 64 are rotated in opposite directions,
The air is compressed and passes through the surge tank 36 and intake pipe 34.
It is introduced into the engine through the intake boat 32.

At least one of 291 and 292 in FIG. 6 is determined as Y.
es, that is, when the water temperature is below θ°C or the oil temperature is below 0°C, or both, it is considered to be an extremely low temperature, and the program then goes to 310, which is the switching point between operating and stopping the supercharger 60. Set the set value a of the rotation speed to N1, and set the set value of the intake air amount to rotation speed ratio to Ql (Fig. 7 (b)).
). The values of Nl and Ql are the values No. when the engine is normally operating,
qo, in other words, the operating range of the supercharger 60 is reduced when the temperature is extremely low. The processing after step 302 is as described above, and the supercharger is operated when it is within the shaded area in FIG. 7(b), and the supercharger 60 is stopped when it is not.

In the embodiment, the cryogenic temperature was determined by combining the cooling water temperature and the oil temperature, but the determination can be made based on only one of them.

Further, the determination can also be made by measuring other temperatures.

Furthermore, the present invention also includes not engaging the entire region of the clutch V-chip at extremely low temperatures.

Effects of the Invention By setting the supercharging region where the clutch is engaged when the engine is at an extremely low temperature on the high rotation side, the supercharger does not operate at least on the low rotation side. At such extremely low temperatures, the engine speed cannot be raised that much and rarely enters the clutch operating range. Therefore, it is possible to prevent shocks and deterioration of clutch durability caused by clutch engagement at extremely low temperatures. Furthermore, since no load is applied to the clutch, the combustibility of the engine is improved and the fuel consumption rate is improved.

[Brief explanation of drawings]

Fig. 1 is a diagram showing the configuration of the present invention, Fig. 2 is an overall view of an embodiment of the present invention, Fig. 3 is a sectional view of the clutch, Fig. 4 is a block diagram of the control circuit, Figs. FIG. 7 is a flowchart showing the software of the control circuit, and FIG. 7 is a graph showing changes in the supercharger operating range according to the temperature according to the present invention. 10-engine body, 16-crankshaft, 46-air flow meter, 60-supercharger, 68-clutch, 100-control circuit, 102-rotation speed sensor, 127-water temperature sensor, 129-oil temperature sensor. Figure 7 (a) (b) Rotation speed N

Claims (1)

[Claims] In an internal combustion engine equipped with a mechanical supercharger in the engine's intake system, a clutch means disposed between the rotating shaft of the engine and a drive shaft of the supercharger, and an operating state detection means for detecting the operating state of the engine. and a clutch actuating means for engaging or disengaging the clutch means in response to an operating state signal from the operating state detecting means;
Temperature detection means detects cryogenic conditions of the engine; and supercharging at cryogenic temperatures sets operating conditions that cause switching between engagement and disengagement of the clutch actuating means according to the temperature conditions of the engine detected by the temperature detection means. 1. A supercharger control device for an internal combustion engine, comprising a set value changing means for changing a set value so as to reduce the range.