JPH03249315A - Valve system for internal combustion engine - Google Patents

Abstract

PURPOSE:To carry out oil supply to a valve operation mode change means speedily upon start-up of engine by connecting an oil pump exclusively for a cylinder head to the hydraulic oil chamber of the means. CONSTITUTION:Between an engine valve V supported on a cylinder head 9 to open or close freely and a crank shaft, there is provided a valve operation mode change means 15 capable of changing operation mode of the valve V in response to change in oil pressure in a hydraulic chamber 31. To the chamber 31 is connected an oil pump Pc arranged exclusively for the head 9 to suck up working oil from an oil bath at the head 9. It is thus possible to relatively reduce the distance between the pump Pc and the chamber 31 to provide opera tion delay of the means 15 upon start-up of engine.

Description

Detailed Description of the Invention A1 Object of the Invention (1) Industrial Application Field The present invention provides an engine valve which is provided between an engine valve and a crankshaft which are supported on a cylinder head so as to be able to open and close, and which is operated in response to changes in oil pressure in a hydraulic chamber. The present invention relates to a valve operating system for an internal combustion engine in which a valve operating mode changing means capable of changing the operating mode of an engine valve is provided.

(2) Prior Art Conventionally, such a valve train has been developed, for example, in Japanese Patent Application Laid-Open No. 61-229
This is already known from Japanese Patent Laid-open No. 912 and Japanese Patent Application Laid-Open No. 64-275516.

(3) Problems to be Solved by the Invention In the conventional valve operating system described above, the oil pump for supplying hydraulic oil to the hydraulic chamber of the valve operation mode changing means pumps hydraulic oil from the oil pan of the engine body. Since the oil pump is generally installed at the bottom of the engine body, the valve is operated at the top of the engine body. ! The distance between the various flattening means hydraulic chamber and the oil pump is relatively long, and therefore the supply of oil to the hydraulic chamber when starting the engine tends to be delayed.

The present invention has been made in view of the above circumstances, and a first object thereof is to provide a valve operating system for an internal combustion engine that can quickly supply oil to a valve operation mode changing means when the engine is started. shall be.

Moreover, in the above-mentioned conventional ones (Japanese Unexamined Patent Publication No. 61-229912 and No. 61-275516), the valve operation 1
! An accumulator is connected to the hydraulic chamber of the i-type changing means via a mutually parallel hydraulic pressure release valve and a one-way valve, and an oil pump is connected between the accumulator and the one-way valve via a check valve. In this valve operation mode changing means, in order to supply oil to the hydraulic chamber, hydraulic oil with a hydraulic pressure lower than the pressure accumulation operation start pressure of the accumulator and higher than the set valve opening pressure of the one-way valve is required. If an oil pump that satisfies these conditions is used, it will be difficult to use it to supply oil to other lubricating parts.

In view of the above circumstances, the present invention aims to provide a valve operating system for an internal combustion engine in which an oil pump can be used not only as a means for changing the valve operation mode but also for supplying oil to other lubricating parts. 2 objectives.

Also, the valve operation of each of the above-mentioned conventional techniques (Japanese Patent Application Laid-Open No. 61-229912 and JP-A No. 61-275516)! !
A cam driven piston is slidably fitted into the upper part of a cylinder body fixed to a cylinder head, and a valve driving piston which forms a hydraulic chamber between the cam driven piston and the cam driven piston is fitted into the lower part of the cylinder body. is slidably fitted to the
When the engine is stopped for a relatively long period of time, hydraulic fluid in the hydraulic chamber leaks downward from a minute gap between the outer surface of the valve drive piston and the inner surface of the cylinder body. For this reason, when the engine valve is in the closed state, the hydraulic oil in the oil passage that connects to the hydraulic chamber above the lowest position of the sliding contact between the valve drive piston and the cylinder body leaks, and when the engine is restarted, the hydraulic oil leaks. There are times when the oil supply to the hydraulic chamber is delayed.

In view of the above circumstances, a third object of the present invention is to provide a valve operating system for an internal combustion engine that avoids delays in refueling a hydraulic chamber due to hydraulic oil leaks.

Valve operation is also provided with an accumulator for accumulating the hydraulic pressure released from the hydraulic chamber when the hydraulic pressure release valve is opened! In the case of an internal combustion engine having a plurality of engine valves, if an accumulator is individually provided for each engine valve, the structure will be complicated and the number of parts will increase.

In view of the above circumstances, a fourth object of the present invention is to provide a valve train for an internal combustion engine that can simplify the structure and reduce the number of parts by minimizing the number of accumulators.

Furthermore, in each of the above-mentioned conventional oil pumps, a single one-way valve that allows flow only from the oil pump side is connected to the hydraulic chamber. However, when a single one-way valve is used as described above, the one-way valve becomes relatively large, and the valve body, which is inevitably large, does not operate quickly, and it is difficult to supply oil to the hydraulic chamber when the valve is opened. There is a risk that the valve body may be delayed, or the seating of the valve body may be delayed when the valve is closed, resulting in unnecessary leakage from the hydraulic chamber.

In view of such circumstances, a fifth object of the present invention is to provide a valve operating system for an internal combustion engine that speeds up the operation of a one-way valve and prevents delays in refueling and unnecessary leaks. purpose.

B9 Structure of the Invention (1) Means for Solving the Problems In order to achieve the above first object, according to the first feature of the present invention, hydraulic oil is pumped up from an oil bath provided in the cylinder head. The oil pump exclusively for the cylinder head is installed in the cylinder head, and the valve operation is 1! It is connected to the hydraulic chamber of the mode changing means.

Further, in order to achieve the above second object, according to a second feature of the present invention, the valve operating mode changing means includes a cam-side operating member interlocked and connected to a valve operating camshaft connected to the crankshaft;
A valve-side operating member interlocked and connected to the engine valve, a hydraulic chamber interposed between the two operating members, an accumulator, a hydraulic release valve interposed between the accumulator and the hydraulic chamber, and a set valve opening. The valve should be opened by pressure to allow the flow of hydraulic oil only to the hydraulic chamber side (a one-way valve that is interposed between the accumulator and the hydraulic chamber bypassing the hydraulic pressure release valve, and a one-way valve that is operated to the side of the -directional valve). A branch for valve operation mode changing means that is provided with a check valve connected between an accumulator and a one-way valve to allow only oil flow, and is connected to the check valve while being branched from an oil supply path connected to an oil pump. A pressure regulating valve is interposed in the oil passage.

In order to achieve the above third object, according to a third feature of the present invention, the valve operating mode changing means is interlocked with the cylinder body identified in the cylinder head and the valve operating camshaft connected to the crankshaft, a cam driven piston that is connected and slidably fitted to the upper part of the cylinder body; a valve driving piston that is linked and connected to the engine valve and slidably fitted to the lower part of the cylinder body; A hydraulic chamber is formed between both pistons in the cylinder body to mutually transmit the operation of the pistons, and a hydraulic pressure release valve is connected to the hydraulic chamber. In the middle part of the branch oil passage for the valve operation mode changing means connected to the chamber, there is a high part that is higher than the horizontal line passing through the lowest end position of the sliding contact part of the valve driving piston and the cylinder body when the engine valve is in the closed state. and a lower part that is lower than the horizontal line and is connected to the hydraulic chamber side end of the higher part.

In order to achieve the above fourth object, according to a fourth feature of the present invention, the valve operating mode changing means includes a cam side operating member interlocked and connected to a valve operating camshaft connected to a crankshaft, and an engine valve. The transmission mechanism includes a hydraulic chamber provided between a valve-side operating member interlocked and connected to the hydraulic pressure chamber, an accumulator, and a hydraulic pressure release valve interposed between the accumulator and the hydraulic chamber. The release valve is arranged to correspond to each of the plurality of engine valves, and the accumulator is arranged in common to the plurality of transmission mechanisms.

Furthermore, in order to achieve the above-mentioned fifth object, the fifth object of the present invention is
According to the feature, between the hydraulic chamber and the branch oil passage for the valve operation mode changing means branched from the oil supply passage connected to the oil pump, there is a hydraulic pressure between the hydraulic chamber and the branch oil passage for the valve operation mode change means. A plurality of mutually parallel one-way valves are interposed to allow hydraulic oil to flow from the branch oil passage for the valve operation mode changing means to the hydraulic chamber side when the difference exceeds a predetermined value.

(2) Effect According to the configuration of the first feature, an oil pump exclusively for the cylinder head is connected to the hydraulic chamber of the valve operation 1M mode changing means disposed in the cylinder head. The distance to the hydraulic chamber can be made relatively short.

Further, according to the configuration of the second feature, the pressure regulating valve regulates the oil pressure supplied to the valve operation mode changing means, so that the valve operation is 1! Using an oil pump that discharges hydraulic oil at a pressure higher than that required by the valve operating mode changing means, it is possible to supply oil to lubricating parts other than the valve operating mode changing means.

According to the configuration of the third feature, the low part is connected to the hydraulic chamber side end of the high part provided in the middle part of the branch oil passage for the valve operation mode changing means, so that when the engine valve is stopped, the cylinder body and valve drive Even if the hydraulic oil in the hydraulic chamber leaks from the sliding contact portion of the piston, the hydraulic oil can be stored at least in the lower part of the branch oil passage for the valve operation mode changing means.

According to the configuration of the fourth feature, since the accumulator is commonly disposed in a plurality of transmission mechanisms, the number of accumulators can be made smaller than the number of transmission mechanisms.

Furthermore, according to the configuration of the fifth feature, by using a plurality of one-way valves, it is possible to downsize each one-way valve,
Accordingly, it becomes possible to speed up the opening and closing operations of each one-way valve, speed up the oil supply to the hydraulic chamber as a whole, and prevent leakage from the hydraulic chamber.

(3) Examples Embodiments of the present invention will be described below with reference to the drawings.

The first embodiment of the present invention will be explained with reference to FIGS. 1 to 3. First, in FIG.
, a lower oil supply system 0° and an upper oil supply system O0 are arranged independently of each other. In the lower oil supply system O1, an oil supply passage 3 equipped with a filter 4 is connected via a relief valve 2 to a discharge port of an oil pump P that pumps up hydraulic oil from an oil pan 1 disposed at the lower part of the engine body E. A plurality of branch oil passages 5, 6, etc. connected to each other and branched from the oil supply passage 3 are connected to the engine body E.
are connected to hydraulic oil consuming parts such as a crank journal part 7 and a cooling jet 8, which are arranged at the lower part of the engine. Further, the upper oil supply system O is a cylinder arranged in the cylinder head 9 to pump up hydraulic oil from an oil bath 10 provided in the cylinder head 9 (see Fig. 2) that constitutes the upper part of the engine main body E. An oil supply path 13 equipped with a filter 12 is connected to a discharge port of a head-only oil pump P via a relief valve 11, and a pressure regulating valve 14
A branch oil passage 16 for the valve operation mode changing means which is connected to the valve operation am changing means 15 and has an orifice 17 and is disposed in the rad 9 to cylinders such as the cam journal part 18 and the cam shower part 19. A branch oil passage 20 for lubrication is connected to each lubricating part provided by the oil supply passage 13.

The valve operation mode changing means 15 is capable of changing the valve opening lift amount operation mode of the engine valve according to the operating state of the engine,
Next, with reference to FIG. 2, the configuration of the portions related to the valve operation mode changing means 15 will be explained.

The cylinder head 9 is provided with an intake valve port 22 that opens at the top of a combustion chamber 21 formed between the cylinder block and the cylinder block (not shown) and communicates with an intake boat 23. The intake valve port 22 can be opened and closed. An intake valve (2) serving as an engine valve is arranged to be vertically movable with an axis inclined laterally from the vertical axis. A flange 24 is provided at the upper end of the intake valve (2), and a valve spring 25 is provided between the flange 24 and the cylinder head 9.
will be reduced. The intake valve V is urged upward, that is, in the valve closing direction, by the spring force of the valve spring 25.

On the other hand, a valve drive camshaft 26 that is interlocked and connected to a crankshaft (not shown) is rotatably disposed above the cylinder head 9. Valve operation mode changing means 15 is interposed between the valve cam 27 and the intake valve V.

The valve operation mode changing means 15 includes the intake valve ■ and the valve operating cam 2.
7, and a hydraulic circuit 32 connected to a hydraulic chamber 31 in the transmission mechanism 30.

The transmission mechanism 30 is slidable on the upper part of the support block 33 while slidingly contacting the cylinder body 34 which is fixed coaxially with the intake valve 2 to the support block 33 fixed to the upper part of the cylinder head 9, and the valve drive cam 27. a lifter 35 fitted to the
A cam driven piston 36 as a cam-side operating member is slidably fitted into the upper part of the cylinder body 34 with its upper end in contact with the lifter 35, and a lower part of the cylinder body 34 with its upper end in contact with the upper end of the intake valve V. and a valve driving piston 37 as a valve-side operating member that is slidably fitted into the piston 36.
．． A hydraulic chamber 31 is formed between 37.

The cylinder body 34 is formed in a cylindrical shape with a partition wall 38 in the middle thereof, and the cam driven piston 36 is formed in the upper part of the cylinder body 34 while defining an upper hydraulic chamber 31a between the cylinder body 34 and the partition wall 38. The valve driving piston 37 is slidably fitted to the lower part of the cylinder body 34 while defining a lower hydraulic chamber 31b between the valve driving piston 37 and the partition wall 38. The upper hydraulic chamber 31a and the lower hydraulic chamber 31b are
It is connected via a check valve 39 disposed on the lower hydraulic chamber 31b side of the partition wall 38 to allow oil to flow only from the upper hydraulic chamber 31a to the lower hydraulic chamber 31b. Thus, a hydraulic chamber 31 is formed. Further, a spring 40 that urges the cam driven piston 36 toward the lifter 35 is housed in the upper hydraulic chamber 31a.

Moreover, an annular recess 41 is provided on the inner surface of the cylinder body 34 below the partition wall 38, and an oil passage 42 is bored in the cylinder body 34 to communicate the annular recess 41 with the upper hydraulic chamber 31a. Further, the upper part of the valve drive piston 37 is formed into a thin-walled cylindrical shape, and an orifice 43 is bored in this thin-walled cylindrical portion to allow the lower hydraulic chamber 31b to communicate with the annular recess 41 at all times.

The transmission mechanism 30 is in the state shown in FIG. 2 when the intake valve V is fully closed when the hydraulic pressure in the hydraulic chamber 31 is not released. is pushed down, the upper hydraulic chamber 31
The hydraulic pressure in the upper hydraulic chamber 31a is guided to the lower hydraulic chamber 31b via the oil passage 42 and the orifice 43, but the check valve 39 opens when the hydraulic pressure in the upper hydraulic chamber 31a is greater than the hydraulic pressure in the lower hydraulic chamber 31b by a predetermined value or more. , hydraulic pressure acts from the upper hydraulic chamber 31a to the lower hydraulic chamber 31b via the check valve 39, and the valve driving piston 37 is pushed down.

During the downward sliding of the valve drive piston 37, the oil passage 42
communicates directly with the lower hydraulic chamber 31b via the annular recess 41, and the amount of oil flowing into the lower hydraulic chamber 31b increases, the valve drive piston 37 is further pushed down, and the intake valve V is moved by the valve spring 25. The valve opens against the spring force.

After the intake valve V is fully open, when the pressing force by the valve operating cam 27 is released, the intake valve (2) is driven upward by the spring force of the valve spring 25, that is, in the valve closing direction. This closing operation of the intake valve (2) also pushes the valve drive piston 37 upward, and the oil in the lower hydraulic chamber 31b is returned to the upper hydraulic chamber 31a via the oil passage 42.

During the closing operation of the intake valve V, the direct communication between the annular recess 41 and the lower hydraulic chamber 31b is released, and the orifice 43 is interposed between the lower hydraulic chamber 31b and the annular recess 41. The amount of oil returned from the hydraulic chamber 31b to the upper hydraulic chamber 31a is limited. Therefore, the upward movement speed of the intake valve (2), that is, the valve closing speed, is slowed down in the middle of the valve-closing operation, and the intake valve (2) is seated gently, thereby reducing the impact upon seating.

Further, the support block 33 is provided with a lift sensor S that detects the upper end of the intake valve V when the intake valve (2) is completely closed.

Hydraulic chamber 31 in the transmission mechanism 30, that is, oil passage 42
If the hydraulic pressure is released during the opening operation of the intake valve ■, the hydraulic chamber 31 will overcome the spring force of the valve spring 25 and lose its transmission function to keep the intake valve ■ open. (2) Although the valve operating cam 27 continues to push the lifter 35 downward, the valve starts to close due to the elastic force of the valve spring 25 from the time of hydraulic pressure release, and the hydraulic chamber 31 contracts.

The hydraulic circuit 32 controls the release of hydraulic pressure from the above-mentioned hydraulic chamber 31 and the supply of hydraulic oil to the hydraulic chamber 31,
It has a hydraulic release valve 44, an accumulator 45, a pair of one-way valves 46, 46, and a check valve 47, and is disposed on the support block 33.

The oil pressure release valve 44 communicates with the oil passage 42 and is connected to the support block 3.
3 and a passage 49 that is bored in the support block 33 and communicates with the pressure storage chamber 63 of the accumulator 45 .

This hydraulic release valve 44 includes a control valve section 51 and a control valve section 5.
1, and an electromagnetic drive section 52 that drives the control valve section 51.
A main valve body 54 that can switch between communication and cutoff is slidably fitted, and a pilot valve 55 that controls opening and closing movement of the main valve body 54 is provided. It is connected to the control valve section 51 to open and close the valve. That is! A valve housing 53 of the control valve section 51 is coupled to a casing 56 of the magnetic drive section 52 .

The main valve body 54 is formed into a growing cylindrical shape. The main valve element 54 is slid into the valve housing 53 by a spring bias in a direction that blocks the passages 48 and 49 while applying the hydraulic pressure of the passage 48, that is, the hydraulic chamber 31, in the valve opening direction. A pilot chamber 57 is formed at the back of the main valve body 54. Therefore, the oil pressure in the passage 48 acts on the main valve body 54 in the valve opening direction, and the oil pressure and spring force in the pilot chamber 57 act on the main valve body 54 in the valve closing direction. Generally, the main valve body 54 is provided with an orifice 58 that allows the passage 48 to communicate with the pilot chamber 57 .

The pilot valve 55 is interposed between the pilot chamber 57 and the outside, and is driven by the electromagnetic drive section 52. That is, the electromagnetic drive unit 52 is a solenoid 59
and a movable core 60 driven by the solenoid 59, and the movable core 6 when the solenoid 59 is excited.
The pilot valve 55 is opened in response to the movement of 0.

In such a hydraulic release valve 44, the tM1 drive unit 52
When the solenoid 59 is excited, the pilot valve 55 opens and the hydraulic pressure in the pilot chamber 57 is released. Therefore, the balance of the hydraulic pressure acting on both sides of the main valve body 54 is lost,
The opening force due to the hydraulic pressure of the passage 48 acting on the front surface overcomes the closing force due to the hydraulic pressure of the pilot chamber 57 and the spring, and the hydraulic release valve 44 is operated to open.

When the pilot valve 55 is closed by demagnetizing the solenoid 59, the hydraulic pressure in the passage 48 acts on the pilot chamber 57 through the orifice 58, and the main valve body 54 operates in the valve closing direction.
The hydraulic release valve 44 is in a closed state.

The accumulator 45 has an accumulator piston 62 slidably fitted into a bottomed sliding hole 61 provided in the support block 33, and pressure is accumulated between the closed end of the sliding hole 61 and the accumulator piston 62. A chamber 63 is defined,
An accumulator spring 65 is compressed between the cap 64 that closes the open end of the sliding hole 88 and the accumulator piston 62 and urges the accumulator piston 62 in a direction to contract the volume of the pressure accumulation chamber 63.

Also referring to FIG.
7 and the passage 48 are arranged in parallel to each other in the support block 33 while bypassing the hydraulic pressure release valve 44, so that the hydraulic pressure in the passage 67 is lower than the set pressure in the passage 48. When the pressure becomes larger than 6, the valve opens and the pressure accumulator 6
3 to the passage 48 only.

These one-way valves 46.46 are provided in a valve chamber 68 provided in the support block 33 while communicating with the passage 48, and have a valve hole 68 which is open into the valve chamber 68 without communicating with the passage 67.
A valve body 70 which can open and close 9 is housed while being biased in the valve closing direction by a spring 71. A tapered valve seat 72 is provided at the opening end of the valve hole 69 to the valve chamber 68, and the valve body 70 is formed in a shape that can be seated on the valve seat 72. That is, the valve body 70 is formed in an upright shape with an umbrella portion 70b provided at the tip of a shaft portion 70a, and
A spherical contact surface 70c that can be seated on the valve seat 69 is formed on the outer surface of the umbrella portion 70b near the tip, and is made of ceramic such as alumina, silicon nitride, and zirconia.

When the valve body 70 is shaped as described above, the one-way valve 46 can be made smaller. In other words, conventionally, the valve body has generally been made into a spherical shape as shown by the chain line in Fig. 3, but by making it upright, it is possible to reduce the axial length and maximum diameter of the valve body. , the whole can be made more compact.

Furthermore, by making the valve body 70 made of ceramic, it is possible to further reduce the weight in addition to the weight reduction associated with the above-mentioned size reduction, and accordingly, it is possible to improve the operational response.

Referring again to FIG. 2, the check valve 47 is connected to the accumulator 4.
5, the intermediate part between the pressure accumulation chamber 63 and both one-way valves 46 and 46, that is, the passage 67, and the branch oil passage 1 for valve actuation tq* changing means.
6, branch oil passage 1 for valve operation mode changing means
6 to the passage 67 side, and a branch oil passage 16 for valve operation mode changing means is provided in a valve chamber 73 provided in the support block 33 and communicating with the passage 67.
A spherical valve element 75 is housed therein, which can open and close a valve hole 74 that communicates with the valve chamber 73 and opens into the valve chamber 73. Moreover, the valve body 75 is
It is made of ceramic such as alumina, silicon nitride, and zirconia.

Such a check valve 47 can be opened even if the oil pressure supplied from the branch oil passage 16 for the valve operation mode changing means is relatively low, and contributes to reducing the output of the cylinder head exclusive oil pump P. I can do it.

By the way, the transmission mechanism 30 and the hydraulic circuit 32 are respectively disposed corresponding to the intake valve (2) of each cylinder in a multi-cylinder internal combustion engine. On the other hand, the branch oil passage 16 for valve operation mode changing means is connected to an upstream portion 16 connected to the oil supply passage 13.
a and the downstream portion 16b connected to the check valve 47 in the hydraulic circuit 32 corresponding to each intake valve (1).
The downstream portion 16b includes a common oil passage 76 common to each hydraulic circuit 32.

The pressure regulating valve 14 includes a housing 78 attached to the side surface of the cylinder head 9, and a spool 79 slidably fitted into the housing 78.

The housing 78 includes a branch oil passage 1 for valve operation mode changing means.
6, an output port 81 connected to the downstream portion 16b of the branch oil passage 16 for valve operation mode changing means, and an output port 81 connected to the oil bath 10 and bored in the cylinder head 9. A release boat 83 connected to the release oil passage 82 is provided. Further, the housing 78 has a large diameter sliding hole 84 with one end closed, and a small diameter sliding hole 85 coaxially connected to the other end of the large diameter sliding hole 84. It is slidably fitted into the moving hole 84 and the small diameter sliding hole 85. Thus, a spring 86 is compressed between one end of the large diameter sliding hole 84 and one end of the spool 79. Further, an output chamber 88 that is connected to the output port 81 via an orifice 87 is formed in the housing 78 so as to face the other end of the spool 79 .

The spool 79 has a position where the input port 80 and the output port 81 are communicated, a position where the output port 81 is isolated from the input port 80 and the release boat 83, and a position where the output port 81 is communicated with the release boat 83. The switching is performed in response to a change in the axial position due to the magnitude relationship between the hydraulic pressure of the spring 86 and the spring force of the spring 86 acting on one end in the axial direction.

In this pressure regulating valve 14, when the oil pressure in the output chamber 88 is low, the spool 79 is connected to the input port 8 as shown in FIG.
0 and the output port 81, and in this state, when hydraulic pressure acts on the input port 80 from the upstream portion 16a of the branch oil passage 16 for valve operation mode changing means, the hydraulic pressure is output from the output port 81. It acts on the downstream part 16b of the branch oil passage 16 for the valve operation mode changing means through the oil pressure, and acts on the output chamber 8 through the orifice 87, and the hydraulic pressure acting on the output chamber 88 causes the spring force of the spring 86 to be Hydraulic pressure acts on spool 79 to push output port 81 to a position separating it from input port 80 and release boat 83 .

When the oil pressure in the output port 81 becomes higher, the spool 79 is driven to a position that communicates the output port 81 with the release boat 83. Therefore, the spool 79 moves so that the spring force of the spring 86 and the hydraulic pressure of the output chamber 88 are balanced, and the spool 79 is moved to a position where the input port 80 and the output port 81 are communicated with each other, and the output port 81 is connected to the input port 80. The position where the output port 81 is separated from the release boat 83 and the position where the output port 81 is communicated with the release boat 83 are switched, thereby controlling the oil pressure of the upstream portion 16a of the branch oil passage 16 for the valve operation type a change means, and It will act on the side portion 16b.

Downstream portion 16b of branch oil passage 16 for valve operation mode changing means
is provided with a common oil passage 76 in the middle to connect the output port 81 of the pressure regulating valve 14 and the check valve 47 in the hydraulic circuit 32 of each intake valve (2). , a high portion 16 ba that is higher than a horizontal line passing through the lowest end position of the sliding contact portion of the valve driving piston 37 and the cylinder body 34 when the intake valve V is in the closed state (state B shown in the second diagram);
A lower portion 16k++ lower than the horizontal line is provided. Moreover, the lower part 16bD includes a common oil passage 76, and the upstream end of the lower part 16b is connected to the higher part 1.
6b, is connected to the hydraulic chamber 31 side end, that is, the downstream end. That is, the hydraulic oil after being pressure regulated by the pressure regulating valve 14 is guided by the high part 16b to a position above the horizontal line, and then guided to a position below the horizontal line by the low part 16be, Furthermore, it is led to the hydraulic circuit 32 of each valve operation mode changing means 15.

At the top of the high portion 16 bU, an air venting means 90 is provided.
is provided. This air venting means 90 has a valve operation of 1! It may be a check valve that closes when hydraulic pressure is applied to the downstream portion 16b of the branch oil passage 16 for the mode changing means, or if some leakage of hydraulic oil is allowed, an orifice may be used to close the downstream portion 16b of the branch oil passage 16. The inside of the portion 16b may be communicated with the outside.

Next, the operation of the first embodiment will be explained. In the valve operation mode changing means 15, when the hydraulic pressure release valve 44 is opened during the opening operation of the intake valve (2), the hydraulic pressure in the hydraulic chamber 31 is The amount of lift of the intake valve (2) can be controlled by controlling the oil pressure release timing.

By the way, when the hydraulic pressure in the hydraulic chamber 31 is released during the valve opening operation, the hydraulic pressure in the pressure accumulation chamber 63 is returned to the hydraulic chamber 31 via the pair of one-way valves 46 and 46 before the next valve opening operation starts.
The shortage is replenished into the hydraulic chamber 31 via the check valve 47.

Therefore, the hydraulic pressure acting on the oil passage 67 via the check valve 47 is
It is necessary for the oil pressure to be between the lower limit pressure, which is the opening pressure of the one-way valve 46° 46, and the upper limit pressure, which is the pressure accumulation start pressure of the accumulator 45. The pressure is regulated by 14. Therefore, the cylinder head 9 such as the cam journal part 18 and the cam shower part 19
The pressure regulating valve 14 controls the hydraulic pressure to the valve operating mode changing means 15, which requires a different hydraulic pressure from the hydraulic pressure at each lubricating part arranged in the pressure regulating valve 14.
A single oil pump PC exclusively for the cylinder head can supply oil to each part with different required oil pressure.
It can be covered by

Moreover, the cylinder head dedicated oil pump P is disposed in the cylinder head 9 to pump up hydraulic oil from an oil bath 10 provided in the cylinder radiator 9.
The distance between the hydraulic chamber 31 of the valve operation mode changing means 15 and the cylinder head exclusive oil pump P6 can be made relatively short. Therefore, when the engine is started, oil is supplied to the hydraulic chamber 3I of the valve operation mode changing means 15. can be carried out promptly.

Furthermore, when the engine operation is stopped for a relatively long period of time, the hydraulic fluid in the hydraulic chamber 31 leaks downward from the minute gap between the outer surface of the valve drive piston 37 and the inner surface of the cylinder body 34 in the valve operation mode changing means 15. do. However, in the downstream portion 16b of the branch oil passage 16 for the valve operation mode changing means, there is a horizontal line passing through the lowest end position of the sliding contact portion of the valve driving piston 37 and the cylinder body 34 when the intake valve (2) is in the closed state. a high part 16b* which is also high; and a low part 1 which is lower than the horizontal line and which is connected to the hydraulic chamber 31 side end of the high part 16bO.
6b, so that even if the leak occurs, the hydraulic oil can be stored at least in the lower portion 16b. Furthermore, since the lower portion 16bo includes a common oil passage 76 with a relatively large capacity, it is possible to store a relatively large amount of hydraulic oil, and the oil pressure chamber 31 can be quickly refilled when the engine is restarted. It is possible to prepare for the start of operation of the valve operation mode changing means 15.

Further, the hydraulic circuit 32 in the valve operation mode changing means 15
is equipped with a pair of one-way valves 46.46 that are parallel to each other, and compared to a case with a single one-way valve, when the opening area is made the same, each one-way valve 46. Miniaturization is possible.

Therefore, the operation of the valve body 70 is speeded up to avoid a delay in supplying oil to the hydraulic chamber 31 when the valve is opened, and the valve body 70 is quickly seated when the valve is closed to prevent unnecessary leakage from occurring from the hydraulic chamber 31. can do.

FIG. 4 shows a second embodiment of the present invention, and parts corresponding to those in the first embodiment are given the same reference numerals.

From the oil supply path 3 connected to the discharge port of the oil pump P that pumps up hydraulic oil from the oil pan 1, there is a crank journal section 7.
The branch oil passages 5, 6, etc. connected to hydraulic oil consuming parts such as the cooling jets 8, etc. are branched, and the valve operating mode changing means 15 has a pressure regulating valve 14.
A branch oil passage 16 for valve operation mode changing means is connected to a branch oil passage 16 for valve operation mode changing means, and a branch oil passage 20 for lubrication has an orifice 17 and is connected to lubricating parts such as a cam journal part 18 and a cam shower part 19. .

According to this second embodiment, since the hydraulic oil adjusted by the pressure regulating valve 14 is supplied to the valve operating mode changing means 15 which requires oil pressure within the range, each lubricating part and the hydraulic oil consuming part are The valve operation mode changing means 15 can be supplied with hydraulic oil having a hydraulic pressure different from the required hydraulic pressure from a single oil pump P.

FIG. 5 shows a third embodiment of the present invention, and parts corresponding to each of the above embodiments are given the same reference numerals.

The transmission mechanism 30, the hydraulic release valve 44, and the one-way valve 46 are
One accumulator 45 and one check valve 47 are disposed in common with the plurality of engine valves V, respectively. In this way,
By reducing the number of accumulators 45 and check valves 47, it is possible to contribute to a reduction in the number of parts, and
Complication of the circuit due to the provision of the accumulator 45 and the check valve 47 can be avoided.

In FIG. 5, the hydraulic power source for supplying hydraulic oil to each transmission mechanism 30 may include an oil bath 10, a cylinder head exclusive oil pump Pc, a relief valve 11, and a filter 14. Also, oil pan 1, oil pump P, relief valve 2 and filter 4
It may also have a configuration consisting of:

In each of the above embodiments, the intake valve has been described as an engine valve, but it is also possible to implement the present invention in connection with an exhaust valve as an engine valve.

C1 Effects of the Invention As described above, according to the first feature of the present invention, the hydraulic chamber of the valve operation mode changing means is supplied with oil from the oil pump dedicated to the cylinder head, so that the gap between the oil pump and the hydraulic chamber is By making the distance relatively short, it is possible to prevent an operation delay during startup.

According to the second feature of the present invention, the hydraulic oil whose pressure is regulated by the pressure regulating valve is supplied to the valve operation mode changing means, so that the valve operation mode can be changed to 1 or more using the minimum necessary oil pump. It becomes possible to supply oil to lubricating parts other than the mode changing means.

According to the third feature of the present invention, since the lower part is connected to the hydraulic chamber side end of the higher part provided in the middle part of the branch oil passage for the valve operation B change means, the hydraulic chamber is operated when the engine valve is stopped. Even if oil leaks, the hydraulic oil can be stored at least in the lower part of the branch oil passage for the valve operation mode changing means, and the hydraulic oil can be promptly supplied to the hydraulic chamber when the engine is restarted. can.

According to the fourth feature of the present invention, since the accumulator is commonly disposed in a plurality of transmission mechanisms, the number of accumulators can be reduced, the number of parts can be reduced, and the circuit configuration can be simplified. .

Furthermore, according to the fifth feature of the present invention, by using a plurality of one-way valves, each one-way valve is miniaturized to speed up the opening/closing operation of each one-way valve, thereby speeding up oil supply to the hydraulic chamber and increasing the hydraulic pressure. It is possible to prevent leakage from the chamber.

[Brief Description of the Drawings] Figures 1 to 3 show a first embodiment of the present invention, in which Figure 1 shows the oil supply system of the engine body, and Figure 2 shows the valve operation Jl! 3 is an enlarged vertical sectional view of a one-way valve, FIG. 4 is a fuel supply system diagram of a second embodiment of the present invention, and FIG. 5 is a third embodiment of the present invention. It is an example refueling system diagram. 3.13... Oil supply path, 9... Cylinder head, 10
...Oil bath, 14...Pressure regulating valve, 15...Valve operation mode changing means, 16...Branch oil passage for valve operation mode changing means, 16b9...Low part, 16 bU...High level Part, 20... branch oil passage for lubrication, 26... valve train camshaft,
30... Transmission mechanism, 31... Hydraulic chamber, 34... Cylinder body, 36... Cam driven piston as a cam side operating member, 37... Valve driving piston as a valve side operating member, 44 ...Hydraulic pressure release valve, 45...Accumulator, 46...One-way valve, 47...Check valve, L...Horizontal line, P...Oil pump, P,...Cylinder head only Oil pump, ■... Intake valve as engine valve Fig. 3

Claims (1)

[Claims] [1] A hydraulic chamber (31) is provided between the engine valve (V), which is supported by the cylinder head (9) so as to be able to open and close, and the crankshaft.
In a valve operating system for an internal combustion engine in which a valve operating mode changing means (15) is interposed that is capable of changing the operating mode of the engine valve (V) in accordance with changes in oil pressure, the oil provided in the cylinder head (9) is A cylinder head exclusive oil pump (P_C) disposed in the cylinder head (9) to pump hydraulic oil from the bus (10) is configured to operate the valve operating mode changing means (15).
) A valve train for an internal combustion engine, characterized in that it is connected to a hydraulic chamber (31) of a valve. [2] Each lubricating part of the valve system, including the valve camshaft (26) connected to the crankshaft and the valve operating mode changing means (15),
A lubrication branch oil path (20) is branched from an oil supply path (13) connected to the cylinder head exclusive oil pump (P_C).
) is connected to the valve train for an internal combustion engine according to claim 1. [3] A hydraulic chamber (31) is located between the engine valve (V), which is supported by the cylinder head (9) so that it can be opened and closed, and the crankshaft.
In a valve operating system for an internal combustion engine, the valve operating mode changing means (15) is provided with a valve operating mode changing means (15) capable of changing the operating mode of the engine valve (V) according to a change in the oil pressure of the engine valve (V), the valve operating mode changing means (15) comprising: A cam-side operating member (36) interlocked and connected to the valve-operating camshaft (26) connected to the crankshaft, a valve-side operating member (37) interlocked and connected to the engine valve (V), and both operating members ( 3
6, 37), an accumulator (45), a hydraulic release valve (44) interposed between the accumulator (45) and the hydraulic chamber (31), It is interposed between the accumulator (45) and the hydraulic chamber (31), bypassing the hydraulic pressure release valve (44), so that the valve opens with valve pressure and allows the flow of hydraulic oil only to the hydraulic chamber (31) side. a one-way valve (46), and a check valve (47) connected between the accumulator (45) and the one-way valve (46) to allow flow of hydraulic oil only to the one-way valve (46) side. and an oil supply path (
An internal combustion engine characterized in that a pressure regulating valve (14) is interposed in a branch oil passage (16) for valve operation mode changing means that is connected to the check valve (47) while being branched from 3, 13). valve train. [4] A hydraulic chamber (31) is located between the engine valve (V), which is supported by the cylinder head (9) so that it can be opened and closed, and the crankshaft.
In a valve operating system for an internal combustion engine, the valve operating mode changing means (15) is provided with a valve operating mode changing means (15) capable of changing the operating mode of the engine valve (V) according to a change in the oil pressure of the engine valve (V), the valve operating mode changing means (15) comprising: The cylinder body (34) fixed to the cylinder head (9)
) and linked to the valve drive camshaft (26) connected to the crankshaft,
A cam driven piston (36) which is connected and slidably fitted into the upper part of the cylinder body (34), and an engine valve (
A valve driving piston (37) is slidably fitted to the lower part of the cylinder body (34) while being interlocked and connected to the cylinder body (V), and the cylinder body Both pistons (36, 37) in the body (34)
It is equipped with a hydraulic chamber (31) formed in between and a hydraulic release valve (44) connected to the hydraulic chamber (31), and branches from the oil supply path (3, 13) connected to the oil pump (P, P_C). An engine valve (V) is located in the middle of the branch oil passage (16) for valve operation mode changing means connected to the hydraulic chamber (31) while
A high part (16b_U) higher than the horizontal line (L) passing through the lowest end position of the sliding contact part of the valve driving piston (37) and the cylinder body (34) in the closed state of the valve, and a lower part (16b_U) lower than the horizontal line (L). and the hydraulic chamber (31
) A lower portion (16b_U) connected to a side end portion. [5] A hydraulic chamber (31) is provided between the engine valve (V), which is supported by the cylinder head (9) so as to be able to open and close, and the crankshaft.
In a valve operating system for an internal combustion engine, the valve operating mode changing means (15) is provided with a valve operating mode changing means (15) capable of changing the operating mode of the engine valve (V) according to a change in the oil pressure of the engine valve (V), the valve operating mode changing means (15) comprising: Interlocking with the valve operating camshaft (26) connected to the crankshaft, interlocking with the cam-side operating member (36) and the engine valve (V) connected,
A hydraulic chamber (31) is provided between the connected valve-side operating member (37).
), an accumulator (45), and a hydraulic release valve (44) interposed between the accumulator (45) and the hydraulic chamber (31),
The transmission mechanism (30) and the hydraulic release valve (44) are arranged to correspond to each of the plurality of engine valves (V) individually, and the accumulator (45) is arranged in common to the plurality of transmission mechanisms (30). A valve train for an internal combustion engine characterized by: [6] A hydraulic chamber (31) is provided between the engine valve (V), which is supported by the cylinder head (9) so as to be able to open and close, and the crankshaft.
In a valve operating system for an internal combustion engine in which a valve operating mode changing means (15) that can change the operating mode of the engine valve (V) according to a change in oil pressure of the engine valve (V) is interposed, an oil supply connected to an oil pump (P, P_C) is provided. A hydraulic chamber (31) and a branch oil passage for valve operation mode changing means are provided between the branch oil passage (16) for valve operation mode changing means branched from the passages (3, 13) and the hydraulic chamber (31). (16) when the oil pressure difference between the valve operating mode changing means branch oil passage (16) and the oil pressure chamber (31) exceeds a predetermined value.
) A valve train for an internal combustion engine, characterized in that a plurality of mutually parallel one-way valves (46, 46) are interposed to allow flow of hydraulic oil to the side.