JPH02308911A - Failure detecting method for valve timing switching control device of interval combustion engine - Google Patents

Abstract

PURPOSE:To positively detect any failure of a valve timing switching mechanism by a relatively simple constitution by comparing a valve timing switching signal with a detected lift amount of a valve. CONSTITUTION:A rod 42a made of ferromagnetic material is integrally formed with a flange part 42i on the inlet valve 40i side, and the tip of the rod 42a is inserted into a lift sensor 19 fixed to a cylinder head 33. The lift sensor 19 is connected to a power supply, and the sensor consists of a primary coil for generating a magnetic field, and a secondary coil electromagnetically connected to the primary coil. Thus, since the more the inserted amount of the rod 42a is the more the output voltage of the lift sensor 19 increases the more the displacement amount (= lift amount) of an inlet valve 40i is in the direction of opening the valve, the more the output voltage of the lift sensor 19 increases. As a result, when the lift amount of the valve, in which valve timing is switched, detected by the lift sensor 19 is different from the valve lift amount at the time when the valve timing indicated by a switching signal is selected, failures can be detected.

Description

[Detailed description of the invention]

(Field of Industrial Application) The present invention relates to a failure detection method of a valve timing switching mechanism in a valve timing switching control device for an internal combustion engine in which the valve timing of an intake valve and/or one valve timing can be changed. (Prior art) A switching mechanism is provided to enable switching of the valve timing of the intake valve and IJI valve of an internal combustion engine. It has been known for a long time to change the valve timing depending on the state (for example, Japanese Patent Publication L!l1lI49-332).
Publication No. 89). In such an engine where the valve timing can be changed, if a problem occurs in the valve timing switching mechanism, the actual valve timing will change according to the command signal even though the control unit outputs a switching command signal. There is a possibility that the actual valve timing will not be affected by other engine controls (fuel efficiency control, ignition timing control, etc.) performed in conjunction with valve timing switching, and engine operation + '1 will be lowered. In order to solve this problem, a failure detection device for detecting a malfunction in the switching mechanism has already been proposed by the applicant of the present application (Japanese Patent Application No. 1, 1983-25529). The proposed switching mechanism includes first and second cams having mutually different profiles, and first and second rocker arms that are in sliding contact with them, and the cam that drives the valve is connected to the first cam. By switching to the second cam and the second cam, the valve timing can be changed to a low speed valve timing suitable for the low rotation range of the engine and a high speed valve timing suitable for the high rotation range. -1 The failure detection device has valve timing control (command from a11 unit (r(
If one son actually changes according to j,; 0; J. 1 and υ.
B) Focusing on the change in the contact state between the second cam and the first and second rocker arms, detect a value corresponding to the electrical resistance between the rocker arm and the camshaft, and use the detected value and command signal. This system detects failures based on the following. (Problem to be solved by the invention) According to the second part of the 11ψ detection device, is it necessary to apply a voltage between the camshaft and the rocker arm in order to detect a value corresponding to the electrical resistance? Since the rocker arm and rocker arm must be insulated from the engine body,
There was a problem that the engine structure was t'H1l. In addition, it is necessary to use a material with high electrical resistance as a material for the cam or rocker arm, and problems remain in terms of durability and manufacturing cost. The present invention has been made in view of two points, and is

[〃Internal combustion engine pulse timing 1 that can reliably detect failure 11i of the exchange mechanism with a relatively fail-safe configuration''
1 target. (Steps for Solving the Problems) In order to achieve the L1 objective described in -, the present invention provides a one-man change mechanism for changing the valve timing of at least one of an intake valve and an exhaust valve of an internal combustion engine, and In a method for detecting a failure of a valve timing switching control device for an internal combustion engine, the valve timing switching control device is equipped with a control stage f which outputs a switching signal to the switching mechanism when the valve timing is switched to the switching state. By comparing the switching signal with the detected lift pawl, a failure of the switching mechanism is detected. Further, it is preferable that the detection of the 0; J claw is performed by a ferromagnetic body that swings together with the valve, and a sensor that outputs a signal according to the amount of displacement of the ferromagnetic body. In addition, when the condition in which the calibration detection riff hijk continues for a predetermined period of time or longer than the predetermined range set according to the switching function, a failure occurs in the switching mechanism. It is desirable to determine that the In addition, the valve timing U/J exchange referred to in this specification is as follows:
``Lift claw, between valve opening and 1j (of 1 closing angle,
J1 means switching only the lift amount or switching between the lift claw and the opening/closing period and/or the opening/closing angle. 0114, it includes stopping one of the plurality of valves in a predetermined i!I!11!mujiJ'j region. A fault is detected when l-ft differs from the predetermined Bronoff l-amount when selecting the valve timing indicated by the 1'' change signal. (Embodiment) An embodiment of the present invention will be described in detail below based on the accompanying drawings. In the same figure, 1 is a pair of intake valves and 1 air cylinder provided in each cylinder.
It is an OIIC inline 4-cylinder engine. A throttle body 3 is provided in the middle of an intake pipe 2 of an engine 1, and a throttle valve 3' is arranged inside the throttle body 3. Throttle valve ``3'' has a throttle valve
Ding+1) Sen1. +4 is connected to the throttle valve 33, and outputs an electric signal corresponding to the opening degree of the throttle valve 33 and supplies it to the electronic controller/roll unit 5. The fuel injection valve r6 is between the engine t and the throttle valve 3'; one intake air 〒'i.2 is a little of the unillustrated intake JP]. Each cylinder valve σ is installed on the flow side, and each injection valve R is connected to a fuel pump I (not shown) and a 13C cylinder valve σ.
Electrically connected to U5! E', the signal from CU 5 controls the opening time of the fuel Fl injection. The ignition plug 22 installed at the engine IMj fσ is connected to the ECU 3 via the drive circuit 21, and the ignition timing Ojg of the ignition plug 22 is determined by 1EclJ5.
is controlled by +111. Further, an electromagnetic brake r213 for performing valve timing switching control iμ, which will be described later, is connected to the output side of the ECU 5. The opening/closing operation of Il magnet 1 through 23 is E C
Controlled by U5. On the other hand, an intake pipe absolute pressure (to Pr+) sensor 8 is installed in the flow directly from the slot I valve 3' via a pipe 7. The absolute pressure signal converted into the signal is supplied to the 1ΣCLJ 5. Further, downstream of it, the intake air ii'ri1. (1" A)
Sensor 9 detects the intake air temperature 'l' and outputs an electric signal to output ECU.
Supply to 5. The temperature of the engine water installed in the main body of engine 1 ('I'w
) The sensor 10 consists of a thermistor, etc., and detects engine water (
Detects the cooling water temperature)'I''W and outputs a temperature signal to !, t: to supply the ECU3.Engine li'i1
The revolution number (Ne) sensor] 1 and the cylinder discrimination (CYl) sensor 12 are mounted around the camshaft of the engine l or around the crankshaft.
The engine rotation speed sensor 11 generates a pulse (hereinafter referred to as "r l' DC signal pulse") at a predetermined crankshaft position every 180 degree rotation of the crankshaft of the engine 1. The cylinder discrimination sensor 12 outputs a borrow pulse at a predetermined crankshaft position of a specific cylinder, and each of these signal pulses is lE', C
! Supplied to J5. The three-way catalyst 14 is disposed in the υ1 trachea 13 of the engine 1, and purifies components such as IIC, Go, and NOx in the υ1 gas. The 02 sensor 15 as a gas concentration detector is installed upstream of the three-way catalyst 4 of the trachea 13, detects the oxygen concentration in the gas, and outputs a signal according to the detected value. Then, 1 co-supply is provided to ECU3. The CU 5 further includes a vehicle speed sensor 16, a gear position sensor 17 that detects the shift position of the transmission, and an oil pressure sensor 18 that detects the oil pressure in the oil supply path (88i, 88e in FIG. 2) of the engine 1, which will be described later. and a lift sensor 19 that detects an intake valve lift attempt, which will be described later, are connected, and detection signals from these sensors are supplied to the IECU 3. EC (J5 shapes input signal waveforms from various sensors,
Input circuit 5a having functions such as adjusting the voltage level to a predetermined level, converting analog signal values into digital signal values, etc.
) 5b, C, PU 51) Storage means 5C1 for storing various calculation programs and calculation results τq executed in the PU 51). Output 1 path 5 (consisting of 1 etc.) that supplies the drive signal. In addition to determining various engine operating conditions such as the feedback control operating region and oven loop control operating region, the engine! I! Based on the following equation (1), the fuel 4'l which is synchronized with the above ']'F C signal pulse is
The fuel injection time 'I゛○U] of the injection valve 6 is calculated. Mot Month = Tj
tij number Ne and absolute j-I in the intake pipe) IIl, and 1
．． (4. J old wood burner ↑゛1 eruption time is determined by
Two maps for low-speed valve timing ('I'it map) and for high-speed valve timing (i'inin map) are stored in the first means 50. These are positive coefficients (Ml) and correction variables, which are determined to predetermined values that optimize fuel consumption characteristics, engine acceleration, and especially engine acceleration characteristics according to engine operating conditions.CPU 5 'l:+ further determines the ignition timing 01g according to the engine rotational speed Ne and the absolute one port in the intake pipe) BΔ. As the θig map for determining the ignition timing, the above ′[
゛Similar to the 1 map, for low speed valve timing (Oig
Two maps, one for high-speed valve timing (o'igu map) and one for high-speed valve timing (o'igu map), are similarly stored in the storage means 5c. CPIJ5b further uses the method shown in FIG. 6, which will be described later.
The solenoid valve 23 outputs the valve timing switching instruction old line.
Opening/closing control is performed. CI) U 5 b is slowly generated like a child chain, and based on the determined result, drives the fuel f'1 injection valve r6, the drive circuit 21, and the solenoid valve 23 (I is connected to the output circuit 5 (Output via 1. 21st part 1 is a vertical cross-sectional view of the main part of the engine 1 described in 1) ij, in which four cylinders 32 are provided in series in a cylinder block 31, and the upper end of the cylinder block 31 is ni e
i'! Cylinder heads to be combined; (3 and each cylinder 3
A combustion chamber 35 is defined between the cylinder head 3 and the piston 34, which is slidably fitted into the cylinder head 3.
3, -phantom intake air 1136 and -moon E air 1'+ 37 are respectively provided in the part forming the large moon surface of each combustion chamber 35, and each intake L'l 3 (i is for each cylinder head) is provided. 3; Intake boat 38 that opens 11 to one of the four 11i1 of 3
Each JJI air 1137 is connected to υ [air port 331] which opens 11 on the other side of the cylinder head 33. Cylinder head: rows 1, 11 for each cylinder 332 of 13
, each intake 1. l 3 (open/close i j-i
In order to guide the capable intake valve 40i and the pair of 1) [air valves p/l Qe that can open and close each JJI air 1137, the guide strips 411° and 41e fit together,
Each intake tube i'/10i and υ ill which are fixed and protrude in one direction from the kite plate/11i, 41a.
The springs A3i and 43c are installed between the flanges 42i and I20 and the cylinder head 33, respectively. These springs 434./130 force each intake valve r401 and each υ1 valve/10e in ten directions, that is, in the valve closing direction. (42i is integrally formed with a rod 42a made of ferromagnetic material +1 material (O-A material with high magnetic permeability), and the tip r (F of the rod 42ε) is inserted into the rift I sensor 19 fixed to the cylinder head 33. The sensor 9 consists of a primary coil which is connected to an electric field and generates a magnetic field, and a secondary coil which is connected to the electric field and which generates a strong magnetic field. Magnetic rod 42f□]
The larger the pushing amount, the larger the mutual inductance (coupling coefficient) between the primary coil and the secondary coil, and the secondary output voltage, that is, the output of the Fritsen 19 increases. (
The larger the amount of movement (-lift amount) of L is in the valve opening direction, the more the output of the lift sensor]9 increases.The output voltage of this lift sensor Intake “4”
The relationship with the operating state of 01 will be further described later. An operating chamber 45 is defined between the cylinder head 33 and a head cover 44 connected to one end of the cylinder head 33, and within this angular movement chamber 45 there is an Ll, an intake bridge riIOi in each cylinder 32 for opening and closing drive. Intake valve for
υ1 air valve for opening and closing the υi air cylinder r40e in each cylinder 32]
The side moving block device 170 is housed and arranged. Both moving block devices 47i and 470 basically have the same configuration, and in the following explanation, the intake block device 170 is housed and arranged. Refer to the side valve device 471 (j+ will be explained by adding the subscript 1, and the υI valve side valve device itel'l 7 e will only be illustrated by adding the subscript e to the reference numeral. Referring also to FIG. 3, the intake intermediary side moving valve device 471 is a
The cam shirt h48i is rotationally driven at a speed ratio of 2, and the shaft 481 corresponds to each cylinder 32.
A high speed cam 511 and a low speed cam 49i provided in
50i (the low speed cam 501 has approximately the same shape as the low speed cam 49i and is located on the opposite side of the low speed cam 191 from the first speed cam 511), and the cam shirt l-18i. Rocker shirt h fixedly arranged in parallel
52 i, a first drive rocker arm 531, a second drive rocker arm 541, and a self-t1. i! is provided between the rocker arm 55i and each rocker arm 53i, 5/l i, 55i corresponding to each cylinder 32, respectively. A knot switching mechanism 561 is provided. In FIG. 3, the connection switching mechanism 56i connects the first switching bin 81 that can connect the first drive rocker arm 531 and the 10110 rocker arm 551, and the 1'-11 rocker arm 55] and the second drive rocker arm 541. a second switching bin 82 and a first and second switching bin 81.8.
A regulation bin 83 that regulates the movement of 2 and each bin 81 to 83
and a return spring 8/l which urges the connection release side. A first guide hole 85 with a bottom and open to the l'1ll1 rocker arm 551 side is bored in the first drive rocker arm 53i in parallel with the rocker shaft 52j.
The first switching bin 81 is slidably fitted into the guide hole 85, and a hydraulic chamber 86 is defined between one end of the first switching bin 81 and the closed end of the first kite hole 85. Furthermore, a passage 87 communicating with the hydraulic chamber 86 is bored in the first drive rocker arm 534, and an oil supply passage 88 is bored in the rocker shirt l□ 52i.
1 is provided, and the oil supply passage 88i communicates with the hydraulic chamber 8 (5) via the passage 87 when the first driving arm 531 is in the swinging state. , the guide holes 89 corresponding to the first guides 685 are connected to the rocker shafts 52i and 5V.
A 211iIj exchange bin 82, which is bored in a row across both side surfaces and whose one end abuts the bottom end of the first exchange bin 81, is slidably fitted into the guide hole 89. 1) The second rotating rocker arm 541 has a second guide hole 90 corresponding to the kite hole 89 marked 1).
The rocker shaft 52 is opened to the side of the lock arm 551]
A disc-shaped regulation bin 8:3, which is bored parallel to the second switching bin 85 and comes into contact with the other end of the second switching bin 85, is slidably fitted into the second guide hole 90 (101). Moreover, a guide tube 91 is fitted in the closed end of the second guide hole 90, and this guide tube 9
A shaft portion 92 that is slidably fitted into the regulating pin 82 is provided integrally with the regulating pin 82 at the same 1j111. Return spring 84
is fitted between the guide tube 91 and the regulating bin 83, and the return spring 84 urges each bin 81, 82, 83 toward the hydraulic chamber 86. In this connection switching mechanism 561, as the hydraulic pressure in the hydraulic chamber 86 increases, the first switching bin 81 fits into the guide hole 89 and the second switching bin 82 fits into the second guide 60.
〇, each rocker arm 513 i, + 5
5 + 154. + is concatenated. Also oil)]:. When the oil pressure in the chamber 86 becomes low, the spring force of the return spring 84 causes the 11jJ change bin 81 to return to the position where the contact surface with the 2nd +JJ change bin 82 corresponds between the 1st jli dynamic rocker arm 531 and the self 1 + rocker arm 55j. , the second switching bin 82 returns to the position where the contact surface with the regulation bin 83 corresponds between the free rocker arm 55f and the second drive rocker arm 54i, so each rocker arm 53i, 55i, 5
The connection state of 4i is released. Next, while referring to No. 3171, the sub-valve gear 471゜4
,7 To explain the oil supply system to e, the oil pan (
An oil pump (not shown) that pumps oil from (not shown) J<
The oil gear lary 98.98' is connected to the oil gear lary 98.98', and η11 pressure is supplied from this oil gear lary 98.98' to each connected IRJ exchanger groove mechanism i, 56e. 47e each 11WI t'
Fli ni il! ! 1? i') Oil is supplied ljH. A switching valve 99 is connected to the oil gear 98 for supplying high and low oil pressure with +yJ1% difference, and the oil supply passage 88 (88e) in each rocker shaft 52i, 52a is connected to Oil gear))8
connected to. Both camshafts l-48i are attached to the "-" side of each cam holder 59.
. Passage forming part 102 extending to row 51i corresponding to 48e
i. 102e are each tightened with a plurality of bolts. Each passage forming Ftlft4'102j, l02e includes a low-speed lubricating oil passage 104i, 10 with both ends closed.
4 B and high-speed lubricating oil passages 105 i and 105 e are provided in parallel with each other, and the low-speed lubricating oil passages 105
171 Soup God] 1st route IO Haku, 104+! is oil gear 98', high speed 1171 oil passage 105i. 105c are connected to the supply η11 paths 88i and 88e, respectively. Furthermore, the low-speed lubricating oil passages [04i and l04e] are connected to the cam holder 51]. The switching block R99 has a port number 1-11fl communicating with the oil gear gallery 98 and a port number 1-120 communicating with the oil supply passages 88i and 88c, and is mounted on one end surface of the cylinder head 33. A subwoofer r122 is fitted into a housing 121 that can be moved freely by 1.gamma.1. A cylinder hole 121 whose upper end is closed with a cap 123 is bored in the housing 121, and the spool valve body 122 forms an operating hydraulic chamber 125 between the cap 123 and slides into the cylinder hole 124. Can be fitted freely. Moreover, the spring chamber 126 formed between the F part of the housing 121 and the spool valve body 121 has a
A spring 127 that forces 2 toward the ten directions, that is, the closing direction.
is stored. The spool valve body 122 has a
An acceptance inspection recess 128 is provided that allows communication between the spool valve body 1120 and the spool valve body 1120, and as shown in FIG. II boat 1] and exit 11 port 120
It is in a state of cutting off the gap between the two. Place the housing 12+ on the end face of the cylinder head 3:3. ] and for high speed''/
There is an oil filter 121 between the November supply path +16
) are held. Also, in the housing 121, there are people l] Bo 1-11! An orifice hole 131 communicating between the bore 1 and the outlet 1-120 is bored. Therefore, Sbourble
With the body 122 in the closed position, the input 1-1 port 1-1
19 and the outlet l-120 are communicated through an orifice hole 131.
88a ()]. 1 Also, there is a spool valve body in the housing +21! 22 is in the closed position, a bypass bow 1-132 is drilled which communicates with the output 11 bow 1 through the point-like portion 128, and this bypass bow H32
The head is connected to the second part of 3:3. The housing 121 includes a person 1-. 1 boat 111] to 1
1i! A conduit 135 that communicates with 1; m k5'L is done. The b-line 137 is connected to a connecting hole 138 formed in the cap 123. Therefore, when the electromagnetic valve p23 is opened, hydraulic pressure is supplied to the hydraulic pressure chamber 125, and the hydraulic pressure under the oil introduced into the hydraulic pressure chamber 125 causes the lisp lubricant 122 to open.
is driven in the direction of the valve opening force. Furthermore, a hydraulic sensor 18 is installed in the housing 121 to detect the oil level in the output ports 120, that is, the oil supply paths 88i and 88e. The device 474 functions to detect whether the engine is running or not.
．． The operation of 47e will be explained below. Here, since each movable block 1'device/17'' and 47e operate in the same way, only the operation of the intake brake R side movable block device 47i will be explained. When the valve command command is output, the electromagnetic brake r23 operates to open the brake
The J exchange valve 99 is opened and the oil pressure of the supply 711 path 881 is turned on. As a result, the connection switching mechanism 56i enters the state (1 movement causes each rocker arm 53'jl 5/Ii, 55j to connect 1ilI), and the high-speed cam 511 causes the
Each rocker arm 5Ji, 541.55i is integrally operated with a pair of intake valves F40i, which are opened and closed at high-speed valve timing with a relatively large valve opening interval of 1g1 and a relatively large riff I amount. On the other hand, G: Electromagnetic from CIJ5, closed to BR23]
When the command signal is output, the electromagnetic valve i'23 and the I-knob switching valve p09 are operated to close, and the hil[ of the feed 4]1 path 881 becomes low. As a result, the link Rζ11'i'J exchange mechanism 561 moves in the opposite direction to the above, and each rocker arm 53i, Fi/Ii,
55ic+) connection is released and the low speed cam/I9
Rocker arm corresponding to i, 50i, +J
i, 54 i are activated, and the pair of intake valves 401 are activated with a low valve timing with a relatively small amount valve period and ref I amount. Figure 4 is a diagram showing the change in the amount of valve I depending on the rotation angle of the crank 1lqb, and for both intake valve C and Lll valve C, the amount of lift when high-speed valve timing is selected is This is approximately twice the lift hoe when low speed valve timing is selected. Therefore, as shown in FIG. 5, the output voltage vLFT of the lift sensor 19 becomes larger when the high-speed valve timing is selected than when the low-speed valve timing is selected. In addition, the number of times the rod 43a is inserted into the lift sensor] 9 and moves back and forth (one movement) with the valve in the direction of the opening r in ↑1 RF time increases as the engine speed Ne increases. The output voltages V1 and Fl of the lift I sensor 19 increase as the engine speed Ne increases by 11. In this way, according to the lift sensor 19, the selected valve timing 1 to 1
．．・Claws can be detected reliably. In addition, since the reciprocating rod 43tl and the lift sensor 19 are not in contact, there is no performance deterioration due to wear.
Durability is ^°6. Next, with reference to FIG. 6, the valve timing switching control by the CU5, ie, ? ! ! The 11 programs explaining the output control program of the signal output to the magnetic block I' 23 are executed as i' l) C (+v+) every time the β pulse is generated. In step S1, the IE CU In step 5, from various sensors, it is determined whether the signal is always manually operated, or whether an abnormality has already occurred in the pond control system, that is, whether fail-safe should be implemented. Absolute II: (PIIA) sensor and 3 in the intake pipe, cylinder discrimination (CYL) sensor 12, engine speed (
TDC) sensor 11, engine water temperature sensor 10, vehicle speed sensor 16 abnormal output, ignition timing control signal output and WN monthly injection control output abnormality, valve timing control (y
An abnormality in the current 111 flowing to the μ electromagnetic block l'23,
Solenoid for valve timing control, output according to opening/closing of #23] 1. of l Baud 1i20. lE')1;I'naga11
The oil pressure switch in the pressure change force sensor 111F sensor 18 detects an abnormality that cannot be confirmed after a predetermined period of time has elapsed, and determines that the engine is in a fail-safe operating state. In addition, cylinder identification (CYI)
When there is an abnormality in one of the C sensors, the output of the other is substituted for the output of the other. Also Riff I Sensor 1
By 9, the connection exchanger 4'11'156 etc. 111:
'T is detected, that is, when a third flag FV'l'FS1 indicating failure detection, which will be described later, has a value of 1, it is also determined that the system is fail-safe. If the answer to step S is affirmative (Yes), that is, fail-safe should be performed, the process proceeds to step S32, which will be described later, and if the answer is negative (
If NO), the process advances to step S2. S2 is a step of determining whether or not it is starting by using the Ne shade;
S3 is the remaining time of the day 1 no timer 1. This is a step of determining whether or not ``s'' has become 0, and is set at a predetermined time (for example, 5 seconds) while starting Lsr (step S4).
), the operation starts at n1 after startup. For S5, engine water temperature 'l' w is set WI+ Iii' ur
S6 is a step of determining whether the vehicle speed V is lower than the extremely low set vehicle speed V+ (for example, 8 km due to hysteresis), that is, whether or not the warm-up is completed.
/5 km), a step of determining whether S is lower than S
7 is a step for determining whether the vehicle equipped with the engine is a manual J1 ((Ml')); 88 is a step for determining whether the vehicle equipped with the engine is a manual J1 ((Ml'));
In the case of T), the collar for the shifter is parked (1))
Step S9 is to determine whether the non-range or neutral (N) range is set.
(For example, 480Orpm/4riO(11'1)I
ll) or more, and during failsafe (answer of step S1 i'i determined (Y(3))
, Setting the delay timer during starting (the answer to step S2 is affirmative (Yes)) and after starting 11. 'j' Ill 1.
S] Progress 1) ij (The answer to step S3 is 1 (Yes)
)), warming up (the answer to step S5 is l! (Yes)
), while stopping +lT or slowing down (if the answer to step S6 is positive (Yes)), when in the N range (if the answer to step S8 is positive (Yes)), and when Ne (if the answer to Ne+ is positive), If (the answer to step S9 is negative (No)), the solenoid valve 23 is closed to maintain the valve timing at the low speed valve timing as described later. In step S9 of 01j, it is determined that Ne≧N e + holds true. , the i' i L map and the '1゛ group map are searched in step Sho, and the current Ne, 1)
1) The '1' value of the map corresponding to △ (F T
i L) and 'J'i++ Map']' i m
'1 (hereinafter referred to as 'I'in)' is calculated, and then in step Sli, AI and M TII (4 are set accordingly)'
From l'v1 table N (i'v according to 4 to 11V
ll), and in step S1.2, this i'VT and [
) 1j loop T' (l u q)
1゛○IIT≧i'VT holds true, that is, whether or not there is a high load state in which the air-fuel mixture is enriched is determined by 'r1]. Here, 'I'VT is a high load judgment value based on fuel injection rJt-IT<, 'l''VT child table engine]!11
It is set according to the number of rotations Ne. When the answer to step SI2 is negative (No), that is, i'our (1'v t) is established, the process proceeds to step S13 and Ne is set to the predetermined upper limit N.
e2 (e.g. 5f100rpm1570orpm) or higher
[Determine whether or not it is -. If the answer to step S], 3 is negative (No), that is, Ne (Ne2 holds true), proceed to step SI4, and compare the ``1'' group obtained in step Sho with the ``1'' group.As a result, Ti+
, )′I″in holds true, step S described later
The timer value 1 of the delay timer is set to 15. V
It is determined whether or not i'OFF is zero (step 516), and if the answer is affirmative (yes), step S]7? lIg
+,: Issues a valve closing command for fr23, that is, a switching command to low speed valve timing. Also, 'I' o 1. + ・r≧
When either of the following conditions holds true: 1) Set the timer value of the solenoid valve opening delay timer to 1. Start by setting the valve to VTOF F (for example, 3 seconds) (step 815), and in step S18 issue an open valve 1 command of valve 23, that is, a command to switch to high-speed valve timing. When the valve closing command is issued in S17, it is determined in step S9 whether or not the >l pressure switch in the oil pressure sensor 18 is turned on, that is, the ill supply path 88i, 88
(Determine whether or not the oil pressure in Step 3 has become low pressure. If the answer is affirmative (yes), that is, the oil pressure switch is turned on and the oil pressure is turned on, the remaining time of the low-speed valve timing switching day 1 no timer [ , determines whether LVI has become 0.The answer to step S2+ is I'J constant (Yes
), that is, L1. When vr=O, in step S23, the remaining time of the high-speed valve timing changeover timer is set to 111+1VT.
I (e.g. 0] seconds), then step S
In step 25, a process is performed to select the ``1'' map used in the fuel injection control routine and the ignition timing map ``1'' IC map and low speed valve timing river ignition timing map (Olgj, MAP) to be used in the fuel injection control routine, and the following steps are performed. At 827, perform 3'T4i to set the rev limiter value N 11 F (: to the value NIIFCI (for example, 7500 rpm) for low-speed valve timing.
is set to prevent over-speeding of the engine, and the engine speed Ne is equal to the rib 1 nozzle value Nopc.
If this happens, fuel will be cut. On the other hand, when the quantity valve fit command is issued in step S18, it is checked in step S20 whether the oil pressure switch in the oil pressure sensor 18 has been turned off and whether the oil pressure in the supply η11 path 881°88e has become high pressure. Discern. If the answer is f7 constant (Yes), that is, the oil pressure switch is turned off, high-speed valve timing 1 is set in step S22.
Jino Exchange Day 1 Remaining time of no timer 1. IIV'r is 0
Determine whether it has become. The answer to step S22 is positive (Yes), that is, 1. When uvr=0,
In step 824, the remaining time (, 1, VT) of the low-speed valve timing switching delay timer is set to 1Jflll (for example, 0.2 seconds), and in step 326, the 'l1 map and point used in the fuel injection control routine are set. -28
= The i'i11 map and the ignition timing map for high-speed valve timing (Oigu map) are selected as the ignition timing map, and in the subsequent step S28, the NIIFC is selected.
is set to 11j (Nupc2 (e.g. 8100+・+1111) for high-speed valve timing. By the way, the double cut fluid delay timer 1.ll marked J-x
V'l'. During the set times of 1, +, and vr, the switching valve 99 is switched after the solenoid valves 2 and 3 are opened and closed, and the oil pressures of the oil supply passages 88 i and 88 e are changed, and the connection switching mechanism 56 i of all cylinders is activated. Response until the switching operation of 56e is completed jYre1] Eyebrow j
The program is set according to S l 9 → S22 → S2 until the oil pressure switch in the oil pressure sensor 18 is turned on when the electromagnetic valves 2 and 3 are switched from open to closed.
Proceeds in the order of /l → S2 → S28, and even after turning on, the connection switching mechanism 5 (ii, 5 (81 ≦) until ir≧ changes to the low speed valve timing side IRJ) -821 → S
26 → 828, and close the valve with the electromagnetic switch l''2;1 or the switching valve 99 lVl, μ+Ht [When the command is issued, Ia
lilJ conversion': If Jr9≦j does not change to the closing side (1) and the oil pressure switch in the oil pressure sensor 18 does not turn on no matter how long it takes, S , + 9 → S22 → 8 in the same way as above.
24→S26→S28, and eventually, unless the coupling switching devices ji'4'56i and 56e of all cylinders are switched to the low-speed valve timing side, the injection control of fuel oil '1 is compatible with the high-speed valve timing. When switching from the electromagnetic block 2:3 to 1j)],
In the same manner as described above, the continuous tenacity J exchange mechanism for all cylinders is
+6 i, unless 560 is switched to the high-speed valve timing side, the injection control 11 of the fuel 1) remains compatible with the low-speed valve timing. On the other hand, if the answer to step S2 in 11i is Yes
), or 1) the answer to step S3 in 1j is negative (No),
Or step S5. When the answer to S6 is II constant (YO8), that is, during startup, before the set time has elapsed after startup, during warm-up, when the vehicle is in the car or when it is slowing down, step 52f is executed.
), issue a valve closing command to the solenoid valve 23, and proceed to step 52.
The process proceeds in the order of 11 to S23, S25, and 827. 1);j
In step S8, if N, 1) range, proceed to step S30 and 1) loop 1'' times to 1' i ++
It is determined whether the map is selected or not, and also when Ne(Na+ is established in the OiJ step), the process proceeds to the step S30.The answer to the step S30 is affirmative (Ye
s), that is, when the previous loop fin map is selected, the previous llL! Electromagnetic j "Open valve 1 delay timer timer value t, V1'(IFI' is set to zero (Step 5)
31), proceed to Step S17, and if the answer to Step 330 is negative (No), that is, if the "I" group map was not used last time, then by performing 1, the connection of all cylinders jR
If J switch groove mechanism i and 56e are not switched to the high-speed valve timing side, S20→S as in 1.
23-S 25->S 27, and the fuel injection control is performed in accordance with the low-speed valve timing regardless of the oil pressure switch in the sensor 18.1. This is the oil inside the oil 1 lower sensor 18. This is a countermeasure when the switch is permanently turned off due to the 19i line, etc. By the way, the above-mentioned Nnpc+ is set higher than N e 2, and normally Nc] is -1,y
Since the valve timing is switched to high-speed valve timing and the Nnpc plant is switched to NIIFC2 at the time of 1, the fuel cut at ~31-NII FCI is not performed. In the operating state in which the process proceeds from steps 82 to S8 to step S29, Ne decreases by -1 to Ne2 due to dry cooking, etc.
Even after 4 times, the low valve timing is maintained, so the N
Fuel cut is performed in OPC+. Also, even when switching from low-speed valve timing to high-speed valve timing, 1
．． Continue hitting until llV'l becomes 0: -j1 several times 5
(i i. Until 56e is actually renovated to the high-speed valve timing side, fuel cut is performed at Nupc+. In addition, the 'l' i L map and the '1' group map in step SIO in -1- In the search processing subroutine, it is determined whether or not the open r command of electromagnetic block "23" was issued in the previous loop, and if the open r command was not issued, i' i + used in step 8.14 is determined. , is ゛l'i+, the value searched from the map, while when the valve opening command is issued, 1'iL is searched ((the value obtained by subtracting '1゛1 from 11 to the predetermined hysteresis claw) Also, in the subroutine for calculating l'VT in step Sll, it is determined whether or not a command to open the electromagnetic brake r23 was issued in the previous loop, and whether the command to open the valve is determined to be If not, use the value calculated from the Tvr table in step S12 (v1 is the value calculated from the Tvr table).However, when the open valve C command is issued, Tvj is calculated from the calculated value by a predetermined hysteresis -ITχ△ Processing is performed to set i'VT to the value jj'j minus 1. When ni+sde step S1 is 1'r constant (Y(4S), that is, in fail-safe mode, ?11 positive, valve 2:3
A valve closing command is issued (Step 532), a fail-safe process to be described later is executed (Step 833), and the process proceeds to Step S27. FIG. 7 shows an example of fail-safe processing in step S33. Engine speed, number Ne or predetermined rotation speed N0FS for map selection (for example, 3.0OOrp+
l” for fast valve timing when higher than n)
i+1 map and 01g for low speed valve timing, +,
When the engine rotational speed NcN is less than the predetermined rotational speed NepS, the I''i map and the Oig map for low-speed valve timing are selected. Map-1 of basic fuel injection time 1'i The − value is 0 for high-speed valve timing in the high engine speed range.
1' group map is better for i'i for low speed valve timing.
Since it is set to be larger than the positive value of the L map, according to the method shown in Figure 7 of the Juki, even though the valve closing command is output to the solenoid valve 23 during failsafe ,"9J IS blue 1'99 or connection switching mechanism 5
Even if a malfunction occurs in 6j, 56e, etc., and the actual valve timing is high-speed valve timing, the air-fuel mixture I:5 may become over lean and the combustion temperature or the inside of the exhaust gas purification system may decrease. The catalyst temperature is excessively high! It is possible to prevent problems such as elution of the spark plug due to ignition, knocking at high revolutions, and deterioration of the durability of the catalyst due to ignition. FIG. 8 is a program flowchart showing a procedure for performing failure detection power 1 based on the output J voltage of the lift sensor I9. In step S51, similarly to step Sl in FIG.
In this case, immediately terminate this program. Step S
If the answer to 51 is negative (No), that is, it is not in failsafe mode, the second flag F”v1Fs2 is set to the value l.
It is determined whether or not it is laborious (step 552). The answer to step S52 is Vt constant (Yes), that is, r”v-rps.
When 2=l, the first flag Fvrrs+ will be described later.
is equal to 1110? Determine the name (step 57)
4). The answer to step S52 or S74 is negative (No);
That is]'VTFS2=0 or Ll:FvrFs+=O(
7) It is determined whether or not the closing valve l'l't'f command signal of the electromagnetic valve p23 is outputting a high signal, that is, whether or not a low-speed valve timing selection command is being output to the ibis (step 5).
53). If the answer to step S53 is negative (No), that is, a high-speed valve timing selection command is output, +'+ii times? 11: uK valve 23σ] Determine whether or not the open r command signal (high speed valve timing selection command) is being output (step S5/I). If the answer to step S53 is negative (NO) and the answer to step S54 is [〒determined (Yes)], that is, if the selection of the i' 6th speed valve timing is continued, step 8
On the other hand, when the answers to step 5rT3゜85/l are both negative (No), that is, when the selection of low-speed valve timing shifts to the selection of high-speed valve timing f7, the high-speed valve timing shown in FIG. This is started by setting the same setting time as the tilJ conversion delay timer tllVT (step 555).
After that, the process advances to step S56. This i'1lVT timer takes into consideration the time required to complete the switching operation of the connected IvJ switch groove mechanism, similar to the switching di-I no timer l; IIVT. In step 85G, it is determined whether or not the count value of the timer is inclined to (jl'l, O).
The flags F'v1ps+ and F″VTFS2 are both 1
11 (set to 0 (step 559), and terminate this program. If the answer to step S56 is 1 (Yes), that is, 'I"uv
When r is 0, the critical voltage (11) of the lift sensor output voltage is searched according to the engine speed Ne. These seven critical voltages are set in a table as shown by the dashed line in FIG. Next, from the output voltage LF'r of the lift sensor 19, -1-th critical 1" old [Vru is changed to -3[i
- 1'l'(subtracted) is fast (1!
(β(>0)) Determine whether or not (Step 8
58). In this case, the answer to step S53 is negative (No).
, that is, since the selection of high-speed valve timing is commanded 419, if the connection switch +l'/56 operates as commanded, the lift sensor output voltage V], p1 is the critical electric current Vi
1); j distribution is higher than the predetermined voltage β (li'), and the answer to step S58 is Vt constant (Yes). In this case, the process advances to step S59 and the first and second flags 'Vi. “511Fv and rps2 both have a value of 0.
is set to On the other hand, if the answer to step 358 is negative (NO), that is, Vl,
p. ``-■ Ding U (When β, the m magnetic brake r23 that constitutes the valve timing switching mechanism 1Mff, the switching brake rlO1 oil supply path 88, the connection switching machine +M'', + (i. It is determined that the continuous & 1i switching mechanism is not operating as instructed, and the process proceeds to step S60.Step S ('+
0, the Karan l-value of the FSII timer (described later) is 4.
1'E Determine whether or not it is equal to O, and if this answer is negative (N
o), i.e., 'i'pSu) when O, it'['i'
, terminate the tree program \j′. When the answer to step 860 is Y(4s), that is, i' Fs++ = O, it is determined whether the first flag Fvrps+ is equal to (1:J l (step 561). Step S6) If the answer is negative (No), that is, the first flag IF'v-rpS+ has a value of 0, then this is changed to ([11
1 and set the TFs++ timer to 1 for a predetermined time.
"Ill" is set to start this (step 562), and this program is terminated.
I timer detects 111j! /J
constant (Ycs), that is, when Fv]p8+=1, the '2nd
The flag Fvtrs2 of is set to the value 1 (step S
6, '3) Terminate this program. According to steps 853 to S [; Predetermined voltage β from critical voltage Vtu
If the state is not higher than V trr -V n+(β), the first flag I・'V'l'Fsl is immediately set to the value 1.
Then, \7 LFT -Vl is set to 1 island in the shape of β for a predetermined time'! When continuing for 'ps++, the second
The flag ■7V・jFS2 is also set to (i', CI). The answer to step S5 J is li set (Yr>, s)
That is, when the selection of low-speed valve timing is commanded, steps S64 to S73 are executed 1-f. Step 5
64=373 are respectively 1) ii step S5/I
~S63, and corresponds to step l? l j-
1/I [Change solenoid valve open J to "Solenoid valve closed" step 564), step S55. 'l' in S56
Step S to change 11Vi to 'I''1.VT (
i5, S(i6), V+, F[-V11+≧β in step S58, Vl-L F i≧β
(However, α>0), step °5 (58), step S60. SG2 'l' FSII i'
r, SL (step S70, 572). '1'L\11 timer and l"Fsl, timer are respectively phantom) It, '1'11ν1 timer and '
It counts a predetermined time set in the same way as the l'psu timer. According to step S6/l'' S73, when the valve timing selection command 1'M is switched from the high-speed side to the low-speed side and the predetermined time 'l'cv+ has elapsed, the lift sensor output type is switched. It: V
tF-r(α) If te is detected, the first flag I'V is immediately set.
i'FSI is set to lil'(+, then Vrl+
−Vl, FT< α state for a predetermined time TpS+, l
1111 When continuing, the second flag Fv'rpr
; 2, the value is increased to 1. Said step S62, 36.3 or step S72°S
73, the first and second flags Fvrps+, Fvrps
When both z are set to the value 1, the step S
52. The answer to S74 is +T constant (Yos), and “
It is determined that each signal 1117 is emitting 1, and the third flag 1, ``V T F sl, is set to the value 1, and a warning is issued by a lamp, buzzer, etc., and this program is terminated. Note that 1) [In step S58, 868 (J), the determination of whether or not V LFT is within the F9F fixed range is made using the four lifts provided on the intake brake r side. I
- Perform this on all sensor outputs, and when at least one ref i sensor output is outside a predetermined range, it is determined that a failure has occurred. According to the construction method shown in FIG. 8 described above, the valve timing selection command signal (valve opening or closing command signal to the electromagnetic valve p23) is j, b, lift sensor output electric power V+, pr,
The magnitude relationship with the predetermined critical voltage group is compared, and based on the comparison result, a failure of the valve timing switching device 411y can be detected quickly and reliably. In addition, Liftsen Lee-19 is the 21st ;! Shown in 1(a) =
j-b, for example, the 21st Wl (1+
), a ferromagnetic +11+ rod 53εl is formed integrally with the low-speed rocker no. 53i, and in order to detect the reciprocating operation of this rod 5;
It may also be provided at the position shown in the same figure. In addition, in the above-mentioned embodiment, the lift sensor is installed on the intake valve R side.
It may be provided on both the ゛ side and the υ1 air bubble r side. (Effects of the Invention) 1. As mentioned above, the valve timing switching control device i! according to claim 1 of the present application. According to the failure detection power 1 method of i', the valve timing switching machine R,? Because of 1"'
TV can be detected by IR with a relatively simple configuration. Furthermore, according to the failure detection method described in claim 2, the reciprocating ferromagnetic f1 body and the sensor are in contact with each other, so that it is possible to avoid deterioration of the detection performance due to wear, and the reliability is improved. Loe's ability to detect 't' makes a roar. Also, 1ltl! Request: 3-11 According to the fault detection method, temporal detection ref l□ 17. 11 by Ninozurekasa
(Detection can be prevented.) 4゜Drawing f!ii A detailed explanation Figure 1 shows an overall configuration diagram of an engine and a control device (31!) to which the acid detection method of the present invention is applied. Fig. 2 is a vertical cross-sectional view of the main parts of the engine, Fig. 3 is a diagram showing the oil supply system including the connection switching mechanism and the hydraulic switching device 1q, and Fig. 4 is a diagram showing the rotation angle of the crank! Figure 5 is a diagram showing the relationship between the output voltage of the lift sensor and the number of engine cycles, Figure 6 is the flowchart of the valve timing change routine (1111111), Figure 7
The figure shows the flowchart i of the fail-safe processing subroutine, and Figure 8 shows the flowchart 1 of the failure detection procedure.
It is. ] Naijozen engine, 5・TjI'f21 control cornilla)・(ni〇U), 11 Engine speed l? sensor, 19・lift sensor, 23 tonmasa b)゛, 401 intake buff p, 40 e-J no 1 air b1゛, 4:3 t)-
a (ferromagnetic 1!] body), 47i, /l7e-motion'j
1. Device, 88 i, 88 (4... Oil supply path, 99
・)Soj exchange b l゛,.

Claims (1)

[Claims] 1. A switching mechanism that switches the valve timing of at least one of an intake valve and an exhaust valve of an internal combustion engine, and a control means that outputs a switching signal to the switching mechanism according to the operating state of the engine. In a failure detection method of a valve timing switching control device for an internal combustion engine, a failure of the switching mechanism is detected by detecting a lift amount of a valve whose valve timing is changed and comparing the switching signal with the detected lift amount. A failure detection method for a valve timing switching control device for an internal combustion engine, characterized by: 2. The internal combustion engine according to claim 1, wherein the lift amount is detected by a ferromagnetic body that oscillates together with the valve and a sensor that outputs a signal according to the amount of displacement of the ferromagnetic body. Failure detection method for valve timing switching control device. 3. Claim 1, wherein it is determined that a failure has occurred in the switching mechanism when the detected lift amount continues to be outside a predetermined range set according to the switching signal for a predetermined time or more. Or the failure detection method of a valve timing switching control device for an internal combustion engine according to 2.