JPH02207111A - Internal combustion engine valve operating state switching device - Google Patents

Abstract

PURPOSE:To enable the secure detection of the operated condition of a piston of a device in which the piston of a connecting device is displaced by the pressurized oil to switch the connected condition of each rocker-arm for low and high speed by detecting oil pressure force of an oil passage communication/ cut-off in response to the displacement of the piston. CONSTITUTION:In a marking device, a pair of intake valve is opened/closed by the rotation of a pair of cam for low speed and a cam for high speed on a cam shaft through the first - the third rocker-arms 5-7. Each rocker-arm 5-7 feeds the pressurized oil to an oil pressure chamber 25 of a connecting device 11 built-in these rocker-arms, and presses the first and the second pistons 21, 22, resisting to a spring 24, to switch each rocker-arm 5-7 from the disconnected condition to the connected condition. In this case, a lubricating oil passage 27 communicated/cut-off by the displacement of the piston 22 and communicated with a guide hole 17 is formed in a rocker shaft 8, and the operated condition of the piston is detected from the output of each oil pressure sensor 45, 46 provided in this side of an orifice 44 in the downstream end of the passage 27 and in the upperstream end of that passage.

Description

Detailed Description of the Invention [Object of the Invention] <Industrial Application Field> The present invention relates to a valve operating state for changing the operating state of an intake valve or an exhaust valve in stages according to the rotational speed of an internal combustion engine. It relates to a switching device.

<Conventional technology> Conventionally, multiple intake valves or exhaust valves have been provided for each cylinder in order to optimize intake and exhaust efficiency over a wide operating range.
Various valve operating mechanisms for internal combustion engines have been proposed in which the number of actuated valves is switched or the actuation timing of the valves is changed in accordance with the rotational speed of the engine. For example, in Japanese Patent Application Laid-Open No. 19911/1989 by the applicant of the present application, a low speed cam and a high speed cam of shapes corresponding to low speed and high speed operation of the engine are installed on a camshaft that is driven to rotate in synchronization with the rotation of the engine. The first and 20th lever arms that are integrally in sliding contact with the low-speed cam and the 30th lever arm that slides in contact with the high-speed cam are adjacently supported on a rocker shaft so as to be movable relative to each other in a relative angle;
Further, a valve operation state switching device for an internal combustion engine is disclosed which is provided with a connecting means that can switch each rocker arm between a state in which each rocker arm is relatively angularly displaced and a state in which the rocker arms are integrally connected.

This connecting means has a piston that slides into a guide hole provided inside each rocker arm, and operates the piston with the base circle of the cam slidingly touching the cam slipper surface of each rocker arm and each guide hole aligned. to connect or disconnect each rocker arm. However, if abnormal wear occurs on the cam slipper surface of the rocker arm,
It is conceivable that due to the change in the rocking angle of the rocker arm, the guide holes become eccentric with respect to each other, thereby interfering with the normal operation of the piston. Therefore, the applicant of the present application has decided to
As disclosed in Japanese Patent No. 47909, a valve operating state switching device for an internal combustion engine is proposed which includes means for detecting malfunction of a piston.

<Problems to be Solved by the Invention> The purpose of the present invention is to improve the above-mentioned conventional technology and to provide a relatively simple solution that can be quickly dealt with when an abnormal situation occurs in the piston operation of the connection switching means. It is an object of the present invention to provide a valve operating state switching device for an internal combustion engine that has a structure that can reliably detect the operating states of pistons in all cylinders using the minimum necessary sensor means.

[Structure of the Invention] <Means for Solving the Problems> According to the present invention, the above object is to provide an intake valve or an exhaust valve that is driven to open and close by a cam via a plurality of adjacently arranged cam followers; connection switching means for reciprocating a piston that slides into a guide hole installed in the cam follower to selectively connect or disconnect the cam follower to enable relative displacement; A valve operating state switching device for an internal combustion engine, comprising: a first passage communicating between the pressure fluid source and the guide hole; and a second passage that selectively communicates with the first passage depending on the operating position of the piston, and the operating state of the piston is determined by sensing the fluid pressure or flow rate in the fluid passage. This is achieved by providing a valve operating state switching device for an internal combustion engine, which is characterized by having a sensor means for detecting.

<Operation> With this arrangement, the first passage and the second passage are in communication with each other in the connected state in which each piston straddles the guide holes of adjacent cam followers and engages at a predetermined operating position, and each cam follower operates simultaneously. In a state where each piston is slid into the guide hole of the corresponding cam follower and each cam follower is relatively displaced, conversely, the first passage and the second passage are blocked or communicated with each other, and the piston operates. If there is an abnormality in the piston, the pressure or flow rate within the fluid passage will change significantly, so by constantly detecting this change, the operating state of the piston can be monitored.

<Embodiments> Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a pair of intake valves 1a and lb provided in the internal combustion engine main body are connected to a crankshaft (not shown).
A pair of low-speed cams 3a, 3b and a single high-speed cam 4 with egg-shaped cross sections are integrally provided on the camshaft 2 which is synchronously driven at two speeds, and each of these cams slides into sliding contact and swings. 1st to 30th arm arms 5 to 7 as cam followers
Opening and closing operations are performed by The engine also includes a pair of exhaust valves (not shown) that are driven to open and close in the same way as the intake valves 1a and 1b described above.

The first to thirtieth lever arms 5 to 7 are rotatably supported adjacent to each other by a rocker shaft 8 installed parallel to and below the camshaft 2.

The first and thirtieth hook arms 5.7 basically have the same shape, have their bases pivotally supported by the rocker shaft 8, and have free ends extending above the intake valves 1a, 1b. Tappet screws 9a and 9b that abut the upper ends of the intake valves 1a and lb are screwed into the free ends of the double-ended hook arms 5.7 so as to be movable forward and backward, and are prevented from loosening by lock nuts 10a and 10b. Furthermore, cam slippers 5a and 7a are formed on the upper surface of the central portion of the double-ended hook arm 5.7 to slide into contact with the low-speed cams 3a and 3b, respectively.

The base of the 20th claw arm 6 is pivotally supported by the rocker shaft 8 between the first and 30th claw arms 5.7.

The free end of the 20th lever arm 6 slightly extends from the rocker shaft 8 toward the middle of both intake valves 1a, lb, and has a cam slipper 6a formed on its upper surface that slides into contact with the high-speed cam, and has a lower surface. is fixed to the cylinder head side or is in contact with the upper end surface of a lid (not shown). This lifter always urges the 20th lever arm 6 upward as a lost motion spring so that the cam slide buckle 6a is always in sliding contact with the high speed cam 4.

A camshaft 2 rotatably supported above the engine body has a low-speed cam 3 corresponding to the first and 30th lever arms 5.7.
a, 3b and a high-speed cam 4 corresponding to the 20th claw arm 6
are integrally connected. As clearly shown in FIG. 2, the low-speed cams 3a and 3b have a relatively small lift and are formed in a cam profile suitable for low-speed operation of the engine, respectively.
It slides into contact with the cam slippers 5a and 7b of No.7. The high-speed cam has a larger lifting height over a wider angle than the low-speed cams 3a and 3b, and is formed with a cam profile suitable for high-speed operation, and is slid onto the cam slipper 6a of the 20th lock arm 6. come into contact with

The first to thirtieth lever arms 5 to 7 can be switched between a state in which they can swing integrally and a state in which they can be relatively displaced by a connecting device 11 installed in their central portions. In addition, retainers 12a and 12 are provided at the top of both intake valves 1a and 1b.
Valve springs 13a and 13b, which are interposed between the engine body and the engine body so as to surround the stem portions of both intake valves 1a and 1b, move both intake valves 1a and 1b in the closing direction, that is, in FIG. It is biased upward at .

As clearly shown in FIG. 3, a first guide hole 14 is formed in the tenth claw arm 5 in parallel with the rocker shaft 8 and opens toward the twentieth claw arm 6 side. 1st
A small diameter portion 15 and an associated step portion 16 are formed on the bottom side of the guide hole 14 . In the 20th Tsuka Arm 6,
A second shaft communicating with the first guide hole 14 of the tenth lever arm 5
A guide hole 17 is provided therethrough. A third guide hole 18 communicating with the second guide hole 17 is bored in the 30th claw arm 7 . A stepped portion 20 is formed in the third guide hole 18, and a small diameter through hole 19 is formed in the bottom of the third guide hole 18.
It is drilled concentrically with the

A first piston 21, a second piston 22, and a stopper 23 are slidably fitted in the first to third guide holes 14, 17, and 18, respectively. The stopper 23 is biased toward the first and twentieth lever arms 5.6 by a compression coil spring 24 to restrict movement of the pistons 21.22. The first piston 21 has such an axial length that the other end does not protrude from the first guide hole 14 at a position where one end thereof contacts the stepped portion 16 of the first guide hole 14 . The second piston 22 has the same length in the axial direction as the second guide hole 17, and has an annular groove 22a having a predetermined width in the axial direction formed around its outer peripheral surface. Further, the stopper 23 has a guide rod 23a inserted into the through hole 19 at the bottom of the third guide hole 18.

A hydraulic chamber 25 is defined between the bottom of the first guide hole 14 and the end surface of the first piston 21 .

On the other hand, in the rocker shaft 8, a hydraulic oil supply passage 26 and a lubricating oil passage 27 connected to a hydraulic pressure supply device, which will be described later, are bored in parallel. The hydraulic oil supply passage 26 communicates with the hydraulic chamber 25 via a communication hole 28 bored in the peripheral wall of the rocker shaft 8 and a communication passage 29 provided inside the tenth lug arm 5, and is connected to the hydraulic chamber 25 through a communication hole 28 formed in the peripheral wall of the rocker shaft 8 and a communication passage 29 provided inside the tenth lug arm 5. Hydraulic oil is always introduced into the hydraulic chamber 25 regardless of the operating state. The lubricating oil passage 27 includes a first oil passage 31 and a second oil passage 32 that are separated from each other.
Equipped with. The first oil passage 31 communicates with the second guide hole 17 via a communication hole 33 bored in the peripheral wall of the rocker shaft 8 and a communication passage 34 provided inside the 20th lever arm 6, and the second oil passage 31 similarly communicates with the second guide hole 17 via a communication hole 35 bored in the peripheral wall of the rocker shaft 8 and a communication path 36 provided inside the 20th claw arm 6.

The hydraulic oil supply passage 26 is connected, for example, to a lubricating oil pump 42 connected to the crankshaft of the engine via a solenoid valve 41 that is opened and closed depending on the operating state of the engine. Lubricating oil sent at a predetermined pressure from the oil pan 43 by the lubricating oil pump 42 is branched before the solenoid valve 41 and is supplied to the lubricating oil passage 27. An orifice 44 is provided at the downstream end of the lubricating oil passage 27, and first and second oil pressure sensors 45, 46 are attached to the front and upstream ends of the orifice 44, respectively, so that the oil pressure in the lubricating oil passage 27 can be constantly monitored. It looks like this.

In the middle and low speed range of the engine, the solenoid valve 41 is closed and the hydraulic pressure chamber 25 of the coupling device 11 is not supplied with hydraulic pressure. Therefore, each piston 21, 22 is positioned in each guide hole 14, 17 by the biasing force of the compression coil spring 24, as shown in FIG. 3, and each rocker arm 5-7 can be angularly displaced relative to each other.

In such an uncoupled state of the coupling device 11, the first and 30th hook arms 5.7 swing in sliding contact with the low-speed cams 3a and 3b, respectively, due to the rotational movement of the camshaft 2, and both intake valves 1a and 1b Drives opening and closing.

In this case, the 20th claw arm 6 slides on the high-speed cam 6 and swings, but does not affect the operation of both intake valves 1a and 1b.

On the other hand, lubricating oil is constantly being pumped into the lubricating oil passage 27. Since the second piston 22 is in the above-mentioned uncoupled position,
Upstream and downstream communication passages 34.3 of the 20th hook arm 6
6 open into the annular groove 22a, and the first oil passage 31 and the second oil passage 32 communicate with each other via the second guide hole 17.

As a result, the lubricating oil is force-fed from the first oil passage 31 through the annular groove 22a to the second oil passage 32, so that the indicated pressure P1 of the first oil pressure sensor 45 shows a high value, and the second oil pressure sensor 46 The indicated pressure P,2 indicates a low value. The normal operating state of each piston is confirmed from these pressures PI and P2.

During high-speed operation of the engine, the solenoid valve 41 is opened and hydraulic pressure is supplied from the hydraulic oil supply passage 26 to the communication hole 28 and the communication passage 29.
The oil is supplied to the hydraulic chamber 25 via the hydraulic pressure chamber 25.

As a result, as shown in FIG.
side, and the second piston 22 moves toward the first piston 21.
is pushed and moves to the 30th arm 7 side. In this way, the first and 20th lever arms 5.6 are connected by the first piston 21, and the second and 30th lever arms 6.7 are connected by the second piston. In this connected state, the amount of rocking of the 20th latch arm 6 that is in sliding contact with the high-speed cam 4 is the largest, so the first and 30th latch arms 5.7
swings together with the 20th lever arm 6, and both intake valves 1a, 1
b is driven to open and close according to the cam profile of the high-speed cam 4.

This operation of the second piston 22 moves the position of the annular groove 22a, and the upstream communication passage 34 of the 20th claw arm 6 is closed by the outer peripheral surface of the second piston 22. Therefore, lubricating oil is no longer supplied from the first oil passage 31 to the second oil passage 32 side, and the command pressure P1 of the first oil pressure sensor 45 becomes low and the command pressure P2 of the second oil pressure sensor 46 becomes high. As in the case of disconnection described above, the normal operating state of each piston is confirmed from these pressures PL and P2.

If the piston does not operate normally during this high-speed operation, since both the upstream and downstream communication passages 34 and 36 open into the annular groove 22a of the second piston 22,
Lubricating oil is sent from the oil passage 1 to the second oil passage 32. Therefore, since the downstream pressure pt is high and the upstream pressure P2 is low,
You can immediately know if the piston is malfunctioning. Also,
If the piston does not operate normally when the engine is switched from high-speed operation to low-speed operation, the first oil passage 31
Lubricating oil cannot be sent from the to the second oil passage 32. Therefore, since the pressure Pi on the downstream side is low and the pressure P2 on the upstream side is high, malfunction of the piston can be immediately detected. In this way, the operating state can be detected for both directions of movement of the piston. The lubricating oil discharged into the engine from the end of the lubricating oil passage 27 is used to lubricate the sliding surfaces of each cam. In this way, the lubricating oil of the engine can be used effectively without increasing the amount.

In this embodiment, the oil pressure sensors are placed at the upstream and downstream ends of the lubricating oil passage 27, but as can be seen from the explanation of the two series, even if one oil pressure sensor is placed at either one of them. Similarly, by sensing changes in the oil pressure within the lubricating oil passage 27, malfunction of the piston can be determined. Also,
Although it is possible that the piston does not operate due to malfunction of the electromagnetic valve 41, this can be easily detected by monitoring the oil pressure in the hydraulic oil supply passage 26 with a separate oil pressure sensor.

In another embodiment according to the present invention, the position of the annular groove 22a provided around the second piston 22 is changed so that the first oil passage 31 and the second oil passage 32 are connected to the outer circumference of the second piston 22 during low speed operation of the engine. The second guide hole 1 is blocked by the surface and is closed during high-speed operation.
7. In this case, the pressures observed on the upstream and downstream sides of the lubricating oil passage 27 have different heights depending on the piston operating position than in the first embodiment described above.

Next, an oil supply system in which another embodiment with such changes is applied to the intake side and exhaust side valve operating devices 51i and 51e of a four-cylinder internal combustion engine will be described with reference to FIG.

In this embodiment, each valve train has a separate rocker shaft having a hydraulic oil supply passage and a lubricating oil passage therein. The rocker shafts 8e on the exhaust side are arranged concentrically and in series, and the hydraulic oil supply passages of the rocker shafts are connected in series to form one hydraulic oil supply passage 26e on the exhaust side. Similarly, the rocker shafts 81 on the intake side are arranged concentrically and in series, and the hydraulic oil supply passages of each rocker shaft are connected in series to form one hydraulic oil supply passage 26i on the intake side. .

Further, the lubricating oil passage 27e on the exhaust side is configured by sequentially connecting the second oil passage 32e of each rocker shaft 8e in series from the upstream side to the downstream side to the first oil passage 31e of the next adjacent rocker shaft 8e. has been done. Similarly, the lubricating oil passage 27i on the intake side connects the second oil passage 32i of each rocker shaft 81 in series to the first oil passage 31i of the next adjacent rocker shaft 81 in series from the upstream side to the downstream side. It is configured.

Oil pump 4 pumping lubricating oil from oil pan 43
A relief valve 52 and an oil filter 53 are installed at the discharge port 1.
An oil gear rally 55 is connected via an oil cooler 54. Lubricating oil is supplied from this oil gear gallery 55 to each journal bearing 57a to 57e of the crankshaft via oil passages 56a to 56e. The oil gear rally 55 is connected to each hydraulic oil supply passage 261126e on the intake side and the exhaust side via a solenoid valve 41 that switches and supplies hydraulic pressure between high and low levels.
It is connected to the. The rear end of each hydraulic oil supply passage 261.26e is connected to an oil supply passage 59i, 59e for supplying oil to the high-speed cam 4 of each valve train 51i, 51e during high-speed operation of the engine through an orifice 581.58e, respectively. It is connected. The oil supply passages 59i, 59e have lubricating oil injection holes 60i, 60 at predetermined positions corresponding to each high-speed cam 4.
e has been established.

Further, in the oil gear gallery 55, an oil passage 61 is branched on the first flow side from the electromagnetic valve 41, and is connected to the exhaust side lubricating oil passage 27e via an orifice 62.

The downstream end of the exhaust side lubricating oil passage 27e is the intake side lubricating oil passage 2.
It is connected to the upstream end of 7i. In this way, one system of lubricating oil passages 27 is configured that connects the valve operating devices 51i and 51e of all cylinders in series from the exhaust side to the intake side. An orifice 44 is provided at the downstream end of the lubricating oil passage 27, and one oil pressure sensor 45 is attached in front of the orifice 44. Furthermore, the ends of the lubricating oil passage 27 are connected to oil supply passages 59i and 59e during high-speed operation.

The oil passage 61 is branched before the orifice 62, and is connected to the intake side and exhaust side valve train 51i via another orifice 63.
, 51e are connected to oil supply paths 64i, 64e for oiling the low speed cams 3a, 3b and the high speed cam 4, respectively. The oil supply passages 64i, 64e are provided with lubricating oil ejection holes 65i, 65e at predetermined positions corresponding to the respective cams. Further, the oil supply passages 64i and 64e include a passage 67i for lubricating each cam journal 66i and 66e, respectively.
67e is connected.

When the engine is operating at low speed, the solenoid valve 41 is closed and low-pressure lubricating oil for lubricating each rocker arm 5 to 7 is supplied to the hydraulic oil supply passages 26i and 26e, so the coupling device 11 does not operate. In the lubricating oil passage 27, communication between the first oil passage 31 and the second oil passage 32 in each valve train is cut off, so the lubricating oil does not flow to the end thereof, and the pressure indicated by the oil pressure sensor 45 is lower than P1. shows a low value. On the other hand, lubricating oil supplied from the oil passage 61 at a predetermined pressure is constantly supplied to the oil supply passage 641 % 64 e
are supplied to each cam 3a from each jet hole 65i, 65e,
3b and 4 are injected.

During high-speed operation of the engine, the solenoid valve 41 is opened and high-pressure lubricating oil is supplied to each hydraulic oil supply passage 26i, 26e.
Each coupling device 11 is activated. Therefore, since the first oil passage 31 and the second oil passage 32 communicate with each other in each valve operating device, the lubricating oil flows to the end of the lubricating oil passage 27, and the command pressure P1 of the oil pressure sensor 45 increases. Each hydraulic oil supply passage 26i, 26
The lubricating oil discharged from the end of the orifice 58i, 5
8e, and is supplied to each oil supply path 59i, 59e, and is injected from each jet hole 601160e to high-speed cam 4 together with the lubricating oil supplied from the end of lubricating oil path 27 through orifice 44.

In this case, if the piston of any one valve train does not operate normally and is in a low speed state, the first oil passage 31 and the second oil passage 32 of the valve train are in a blocked state. In this case, the lubricating oil does not flow to the end of the lubricating oil passage 27. Therefore,
Since the indicated pressure P1 of the oil pressure sensor 45 is low, abnormalities in the piston operating state can be easily detected. Furthermore, by providing the oil pressure sensor 45 at the upstream end of the lubricating oil passage 27 instead of at the downstream end, the piston operating state can be similarly detected. In this case, the hydraulic pressure sensor will indicate a higher pressure than normal due to the abnormal operation of the piston.

In the embodiment shown in FIG. 5, the intake side and exhaust side valve gears of all cylinders are connected in series to form one lubricating oil passage.
If the lubricating oil passages are configured independently on the intake side and the exhaust side, malfunction of the piston can be detected separately. Furthermore, if each valve train is replaced with the embodiment shown in FIGS. 3 and 4, it is possible to detect malfunction of the piston when the engine is operating at low speed.

In general, lubricating oil has poor fluidity in low-temperature conditions such as when starting an engine or in cold weather, so the piston malfunction detection system described above should not be activated until the lubricating oil temperature rises to a certain level to prevent malfunction. is preferred.

Note that the driving means for switching the piston may be an electrical or mechanical device instead of a hydraulic type. Also,
The rocker arm may be of the center pivot type and the transmission member may be a direct type packet lifter. Furthermore,
The opening position of each communication path into the guide hole is not limited to the first embodiment. Further, in this embodiment, the lubricating oil passage communicating through the guide hole is provided in the 20th lubricant arm, but it may be provided in the 10th lubricant arm or the 30th lubricant arm. Further, in the above embodiment, the operating timing of both the two valves is switched using a 3-split rocker arm, but in the present invention, the 2-split rocker arm is driven by a single cam, and one valve is switched at a predetermined rotational speed. The present invention can similarly be applied to a valve operation state switching device that is configured to rest and connects and releases the rocker arm with a single screw.

[Effects of the Invention] As described above, according to the present invention, the lubricating oil is made up of a first oil passage and a second oil passage that are communicated with or blocked from each other via the guide hole depending on the operating position of any one piston. A piston that can be placed in a metal cylinder using a minimum number of sensor means by providing a passage in the rocker shaft and detecting the oil pressure in the lubricating oil passage with a hydraulic pressure sensor installed on the upstream or downstream side of each lubricating oil passage. Since the operating state of the valve operating state can be reliably detected, the usability and reliability of the valve operating state switching device for the internal combustion engine are improved, and other effects are great.

[Brief explanation of the drawing]

FIG. 1 is a top view of a valve train having a valve operating state switching device to which the present invention is applied. FIG. 2 is a view taken from the arrow ■ in FIG. 1. FIG. 3 is a sectional view taken along the line ■-■ in FIG. 2 in a low-speed operating state. FIG. 4 is a hydraulic circuit diagram similar to FIG. 3 in a high-speed operating state. FIG. 5 is a hydraulic circuit diagram of a refueling system showing another embodiment applied to a four-cylinder internal combustion engine. 1a, 1b... Intake valve 2... Camshaft 3a, 3b.
...Low speed cam 4...High speed cam 5...10th lever arm 6
...20th Tsuka Arm 7...30th Tsuka Arm 5a
~7a...Cam slippers 8.8i, 8e...Rocker shafts 9a, 9b...Tappet screws 10a, 10b...Lock nuts 11...Connection devices 12a, 12b...Retainers 13a, 13b...・Valve spring 14...First guide hole 15...Small diameter part 16...Step part
17...Second guide hole 18...Third guide hole 1
9...Through hole 20...Step part 21...First piston 22...Second piston 22a...Annular groove 23...Stopper 23a...Guide rod 24
... Compression coil spring 25 ... Hydraulic chamber 26.26i,
26e...Hydraulic oil supply passage 27.27i, 27e...
・Lubricating oil passage 28...Communication hole 29...Communication passage 31...First oil path 32...Second oil path 33・
...Communication hole 34...Communication path 35...Communication hole 36...Communication path 41...Solenoid valve 4
2... Lubricating oil pump 43... Oil pan 44.
... Orifice 45 ... First oil pressure sensor 46 ... Second oil pressure sensor 51i, 51e ... Valve train 52 ... Relief valve 53 ... Oil filter 5
4... Oil cooler 55... Oil gear rally 56
a to 56e... Passages 57a to 57e... Cam journals 58i, 58e... Orifices 59i, 59e... Oil supply passages 60i, 60e... Lubricating oil jet holes 61... Passages 64i, 64e 65i , 65e 66i, 66e 67 i, 67e 62.63... Orifice... Oil supply path... Lubricating oil jet hole... Cam journal... Passage Patent Applicant Hon EII Giken Kogyo Co., Ltd.
Patent Attorney Yo Oshima - Figure 2

Claims (4)

[Claims] (1) An intake valve or an exhaust valve that is driven to open and close by a cam through a plurality of adjacent cam followers, and a piston that slides into a guide hole provided in the cam follower are reciprocated to selectively operate the cam followers. A valve operation state switching device for an internal combustion engine, comprising a connection switching means that connects or disconnects to enable relative displacement, and a fluid passage that communicates a pressure fluid source with the inside of the engine via the guide hole, A fluid passage includes a first passage communicating between the pressure fluid source and the guide hole, and a first passage communicating between the guide hole and the interior of the engine and selectively communicating with the first passage depending on the actuation position of the piston. 1. A valve operating state switching device for an internal combustion engine, comprising two passages, the fluid passage having sensor means for detecting the operating state of the piston by detecting the fluid pressure or flow rate. (2) The valve operating state switching device for an internal combustion engine according to claim 1, wherein the sensor means is arranged at both an upstream end and a downstream end of the fluid passage. (3) The fluid passage consists of one system of passages in which the second passage of each cylinder is sequentially connected to the first passage of the next adjacent cylinder from the upstream side to the downstream side. Claim 1 or 2 characterized by
A valve operating state switching device for an internal combustion engine as described in 2. (4) The lubricating oil discharged into the engine from the fluid passage is supplied to a valve train lubricating section of the engine, according to any one of claims 1 to 3. Valve operating state switching device for internal combustion engines.