JPH05202708A - Valve system of engine - Google Patents

Abstract

PURPOSE:To reduce the weight and a cost by greatly reducing the number of actuators, in a multiple cylinder engine having a plurality of intake valves or exhaust valves. CONSTITUTION:The valve system of an engine is provided with a first cylinder 2 provided with a first piston 53 slidably, second cylinders 3A to 3F respectively provided with intake valves 58A to 58C of respective cylinders in the engine being capable of making reciprocating motion, and a laminated piezoelectric element 56 by which the piston 53 is reciprocating-driven repeatedly. An oil pressure distributor 20 is connected to the cylinder 2 through a control main piping 15, and also one-side ends of pipings 4A to 4C per cylinder which are communicated with the control main piping 15 selectly by the distributor 20 at a prescribed time clearance more than the reciprocating time of the piston 53. And the cylinders 3A to 3E are respectively connected to the other-side ends of respective pipings 4A to 4C per summarized cylinder group.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a valve operating system for an engine, and more particularly to a valve operating system for an engine in which an intake valve or an exhaust valve of a multi-cylinder engine is opened and closed by a remote operation using a single actuator. Regarding the valve device.

[0002]

2. Description of the Related Art The most common valve operating system for an engine is a system in which an intake or exhaust valve is mechanically opened and closed by using a cam mechanism driven by the engine. In addition, a system that employs a so-called electric valve mechanism that directly opens and closes a valve by using an electric drive means such as a solenoid (for example, Japanese Patent Laid-Open No. 58-183805).
In addition, a displacement amplification mechanism using a non-compressible fluid is interposed between an intake or exhaust valve of the engine and an electric drive means (comprising a piezoelectric element) for electrically opening and closing the valve. There is known a system that amplifies the displacement of the driving means and transmits it to the valve side (for example, JP-A-61-58909).

[0003]

However, in any of the above-described conventional valve operating devices, in the case of a multi-cylinder engine, when there are a plurality of intake valves and exhaust valves for each air, for example, the valve area can be increased. In addition, the inertial weight becomes smaller and the intake efficiency can be improved, so the DOHC (Double Over Head
In the case of four valves (4 valves) such as a camshaft, many actuators are required to move the valves of all cylinders of the intake system (or exhaust system), and the weight is inevitably heavy. The cost was high. For these reasons, weight reduction and cost reduction have been major issues in engine valve trains.

[0004]

SUMMARY OF THE INVENTION The present invention has been made under the above circumstances, and an object thereof is to reduce the number of actuators significantly, especially in the case of a multi-cylinder engine having a plurality of intake valves or exhaust valves. Accordingly, it is an object of the present invention to provide a valve operating device for an engine that can reduce the weight and cost.

[0005]

In order to achieve the above-mentioned object, a valve operating system of the present invention is provided with a first piston provided outside the engine and provided with a first piston slidably along the longitudinal direction thereof. A cylinder, a plurality of second cylinders each provided with an intake valve or an exhaust valve of each cylinder of the engine so as to reciprocate along its longitudinal direction, and a first piston repeatedly reciprocally drive in its sliding direction. An actuator, and a hydraulic distributor is connected to the first cylinder through a control main pipe, and the hydraulic distributor is alternately arranged at a predetermined time interval longer than the reciprocating time of the first piston by the hydraulic distributor. In addition, one end of each of the plurality of cylinder-by-cylinder pipes that are selectively communicated with the control main pipe is connected to each other, and the second cylinder is connected to the other end of each of the cylinder-by-cylinder pipes collectively for each cylinder. Structure It is.

[0006]

The cylinder-by-cylinder pipe of one of the cylinders is connected to the control main pipe by the hydraulic distributor, and the hydraulic pressure of the hydraulic oil generated by the reciprocating motion of the first piston driven by the actuator is connected to the cylinder-by-cylinder pipe that is in communication with the control main pipe. The hydraulic pressure is sent to open and close an intake valve (or an exhaust valve) mounted on a second cylinder connected to the cylinder-by-cylinder pipe. And
When the first piston reciprocates once and the opening / closing (operation) of the intake valve or the exhaust valve is completed, the cylinder-by-cylinder pipe of another cylinder is communicated with the control main pipe by the hydraulic distributor, and the same as before by that cylinder The intake valve (or) exhaust valve corresponding to the pipe opens and closes. In this way, the cylinders for each cylinder are alternately and alternately communicated with the control main pipe by the hydraulic distributor, and the actuator drives the first piston once reciprocatingly within each communication time, whereby a plurality of cylinders are connected. The intake valve (or exhaust valve) is repeatedly opened and closed without overlapping.

[0007]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT A preferred embodiment of the present invention will be described below with reference to FIGS.

FIG. 1 shows a valve train 1 for opening and closing an intake valve of a 3-cylinder 4-valve engine. The valve gear 1 includes a first cylinder 2 provided outside the engine and provided with a first piston 53 slidably along the longitudinal direction thereof, and intake valves 58A, 58B for the respective cylinders of the engine.
58C each equipped with a pair of cylinders, each of which is reciprocally movable along its longitudinal direction, has a total of six second cylinders 3A,
3B, 3C, 3D, 3E, 3F and the first piston 53
And a laminated piezoelectric element 56 as an actuator that repeatedly reciprocates in the sliding direction. Also, the first
A hydraulic distributor 20 is connected to the cylinder 2 via a control main pipe 15, and the hydraulic distributor 20 is connected to the cylinder 2 at a predetermined time interval longer than the reciprocating time of the first piston 53. One end of each of the cylinder-by-cylinder pipes 4A, 4B, 4C, which are alternately and alternatively communicated with the control main pipe 15, is connected respectively, and the other end of each of the cylinder-by-cylinder pipes 4A, 4B, 4C is provided with a second pipe. Cylinders 3A, 3B, 3C, 3
D, 3E, and 3F are connected together for each cylinder.

This will be described in more detail. First cylinder 2
1 is a bottomed cylindrical member whose lower end in FIG. 1 is fully opened and whose upper end is closed except for the central portion, and which is mounted at a predetermined distance from the engine with the lower end opening closed. It is fixed on the member 5. The peripheral edge of the opening at the center of the upper end surface of the first cylinder 2 is provided so as to project outward, and one end of the control main pipe 15 is connected to this projecting portion 2A via a connecting member 6. Control main pipe 15
The other end of is connected to the hydraulic distributor 20. As described above, the first piston 53 is slidably mounted inside the first cylinder 2, and one end (upper end in the figure) is provided between the first piston 53 and the mounting member 5. Is fixed to the lower surface of the first piston 53, and the above-described laminated piezoelectric element 56 having the other end (the lower end in the drawing) fixed to the upper surface of the mounting member 5 is interposed. This laminated piezoelectric element 5
6 includes an engine control unit (hereinafter, "EC
U ”. ) 50 is connected to this ECU
The energization timing and energization time of the engine are controlled by 50 according to the operating state of the engine.

FIG. 2 specifically shows the mounting and internal structure of the one second cylinder 3A equipped with the intake valve 58A of the cylinder (# 1). In FIG. 2, the second cylinder 3A is made of a slightly thick cylindrical member,
With the cylinder block 60 of the engine closed at one end (lower end in the figure), the cylinder block 60
It is fixed on. At the other end (upper end in the figure) of the second cylinder 3A, the central portion is closed by a hose mounting member 7 which also serves as a lid member having an opening having substantially the same diameter as the hose 4. And this hose attachment member 7
One end of the hose 4 is connected to the protruding end of the hose 4 via a connecting member 8. The other end of the hose 4 is connected to the hydraulic distributor 20 via a bifurcated connecting member 11 and a cylinder-specific pipe 4A as shown in FIG. Further, in the second cylinder 3A, as shown in FIG. 2, the plunger 57 faces one end (upper end in the drawing) to the inside of the second cylinder 3A and the other end (lower end in the drawing) to the outside. The second with no condition
The cylinder 3A is reciprocally movable along the longitudinal direction of the cylinder 3A, and an intake valve 58A is integrally provided at the other end of the plunger 57. The plunger 57 is provided with a guide member 9 that penetrates the cylinder head 60.
It is configured to be able to reciprocate in the directions of the arrows A and B in the figure along. The intake valve 58A provided on the other end side of the plunger 57 is actually provided at a position where the inlet of the intake port (not shown) on the cylinder block 60 side can be opened and closed. Then, the plunger 57 and the intake valve 58A are
The compression coil spring 63 interposed between the spring retainer 12 fixed to the upper end portion of the plunger 57 in FIG. 2 and the guide member 9 is urged in the direction of arrow A in the figure. Here, the state of FIG. 2 shows the state where the valve lift is zero when the compression coil spring 63 is maximally extended.

Further, in this embodiment, an upper lift check groove 65 and a lower lift check groove 66 are formed on the outer peripheral portion of the plunger 57 along the longitudinal direction at predetermined intervals.
These lift check grooves 65 and 66 are provided in the plunger 57.
2 when the valve lift is zero and when the valve lift reaches the maximum position (not shown) as shown in FIG. 2, it is operated with the working fluid supply passage 70 for communicating the inside of the second cylinder 3A with the outside. A fluid discharge passage 80 is provided. The working fluid discharge-only passage 80 has a second
The first passage portion 80A having a U-shape extending from the inside of the cylinder 3A to the inner peripheral surface of the guide member 9 through a part of the peripheral wall of the cylinder 3A, and the first passage portion 80A opposite to the first passage portion 80A via the plunger 57. The guide member 9 and the second at corresponding positions on the side
And an L-shaped second passage portion 80B formed on the peripheral wall of the cylinder 3A. Then, at the lower left end of the second passage portion 80B in the drawing, the passage portion 80 is
A first check valve 71 that allows only the flow of oil from the B side to the outside and blocks the flow in the opposite direction is provided. Similarly, the working fluid replenishment passage 70 has a U-shaped first passage portion 7 extending from the inside of the second cylinder 3A to the inner peripheral surface of the guide member 9 through a part of the peripheral wall of the cylinder 3A.
0A and the first passage portion 70A via the plunger 57.
Guide member 9 and cylinder 3 at the corresponding positions on the opposite side to
It is configured to include an L-shaped second passage portion 70B formed on the peripheral wall of A. A second check valve 72 that allows only the flow of oil from the outside to the side of the passage 70B and blocks the flow in the opposite direction is provided at the lower left end of the second passage 70B in the figure. Has been. An oil passage 90 connected to an oil supply means (engine hydraulic pressure) not shown is provided in the cylinder block 60 outside the check valves 71 and 72. 1 and 2, reference numerals 91 and 92 denote oil seals.

Other second cylinders 3B, 3C, 3
The structure of D, 3E and 3F parts is also the second cylinder 3A of FIG.
Is almost the same as.

The hydraulic distributor 20 includes a rotor 21 having a central angle of 240 degrees as shown in FIG. 3 and a shaft 22 (see FIG. 1) which constitutes a rotation shaft of the rotor 21, The rotor 21 is rotated by 22 and, as is clear from FIG. 3, the central angle of the portion not blocked by the rotor 21 is 120 degrees. Therefore, the hydraulic distributor 20 causes the central angle in the control main pipe 15. Hydraulic pressure is cylinder-specific piping 4A,
It is designed to be distributed to 4B and 4C by 1/3.
That is, the shaft 22 rotates at half the engine speed as in the case of a normal camshaft. Therefore, the cylinder-by-cylinder pipes 4A, 4B, and 4C are moved during one stroke of the crankshaft. Is alternately and alternately communicated with the control main pipe 15 by 1/3 of the rotation angle of 720 degrees, that is, by 240 degrees,
Pressure is applied to the oil 10 (see FIG. 1 to FIG. 2) as hydraulic oil in the cylinder-by-cylinder piping of the communicating cylinders through the first piston 53 according to the displacement of the laminated piezoelectric element 56. In the case of a normal engine, the working angle of the intake valve is within 240 degrees. Therefore, in the case of the present embodiment having three cylinders, as shown in FIG.
It shows with. The operating angle of) does not overlap with other cylinders and can be distributed well. Further, as shown in FIG. 4, the time T during which the cylinder-by-cylinder pipes are brought into communication with the control main pipe 15 by the rotation of the rotor 21 is based on the reciprocating time of the first piston 53, that is, the operating period t of the laminated piezoelectric element 56. It's getting a little bigger.

Next, the overall operation of the above embodiment will be described with reference to FIG.

First, while the engine is stopped, the laminated piezoelectric element 56.
When no displacement occurs, the pressure does not act on the oil 10 inside the first cylinder 2 and the control main pipe 15, so that the intake valves 58A, 58B, 58C are all returned to their original positions by the compression coil spring 63. It is held and closed.

When the engine is started and the laminated piezoelectric element 56 is energized by the ECU 50 and the displacement is changed as shown in FIG. 4, the first piston 53 is reciprocally driven in the direction of arrow AB. At this time, the cylinder (# 1) communicated with the control main pipe 15 by the hydraulic distributor 20.
The hydraulic pressure generated by the reciprocating motion of the first piston 53 is applied to the cylinder-by-cylinder pipe 4A, and the plungers 57, 57 in the second cylinders 3A, 3B connected to the cylinder-by-cylinder pipe 4A are moved by the arrow B. It is reciprocally driven in the −A direction, whereby the intake valves 58A and 58A are opened and closed.

Here, the principle of opening / closing the intake valve 58A will be described in detail. When the laminated piezoelectric element 56 is energized by the ECU 50, each piezoelectric element 56A (see FIG. 1) constituting the laminated piezoelectric element 56 is activated. The laminated piezoelectric element 56 extending in the axial direction generates displacement in the arrow A direction, and the first piston 53 is driven in the arrow A direction. At this time, the first piston 53 applies a pressure to the oil 10 in the first cylinder 2 and the control main pipe 15, and this oil pressure causes the oil pressure in the control main pipe 15.
To the second cylinder 3 via a cylinder-specific pipe 4A communicating with the second cylinder 3
The pressure is applied to the pressure receiving surface of the plunger 57 in A and 3B, the plunger 57 is moved in the direction of arrow B, and the intake valve 58 is opened via the plunger 57. On the other hand, when energization is stopped by the ECU 50, each piezoelectric element 56A forming the laminated piezoelectric element 56 returns to its original shape.
Therefore, the first piston 53 moves in the direction of arrow B and returns to the original position. Therefore, the oil pressure of the oil 10 inside suddenly becomes negative pressure, and the intake valve 58A returns to the original position. In this way, the intake valve 58A is reciprocally driven in the direction of the arrow BA, whereby the intake valve 58 is opened and closed.

When the first piston 53 reciprocates once and the opening / closing (operation) of the intake valves 58A, 58A is completed, the hydraulic distributor 20 connects the cylinder-by-cylinder pipe 4B to the control main pipe 15. The communication is performed, and the intake valves 58B, 58B corresponding to the cylinder-by-cylinder pipe 4B are opened and closed in the same manner as before. In this manner, the cylinders 4A, 4B, 4C for each cylinder are alternately and alternately communicated with the control main pipe 15 by the hydraulic distributor 20, and the laminated piezoelectric element 56 causes the laminated piezoelectric element 56 to reach the first piston 53 within each communication time. Of the intake valves 58A, 58B, 58C of the cylinders (# 1, # 2, # 3)
Are sequentially opened and closed without overlapping.

In this case, the displacement of the laminated piezoelectric element 56 is amplified according to the ratio of the pressure receiving areas of the first piston 53 and the plunger 57 and is transmitted to the intake valve. Further, when the oil 10 leaks from the oil seal 91 or 92 during use and the pressure of the oil 10 inside falls below a specified value, the intake valve 58A is not lifted and the oil is supplied from an oil supply means (not shown) in the state of FIG. The check valve 72 is opened by the pressure of the oil, and the oil is replenished through the second passage portion 70B, the lower lift check groove 66, and the first passage portion 70A that constitute the passage 70 for exclusive use of the working fluid replenishment. (Here, the amount of oil to be replenished is a small amount of oil leaked from the oil seal.) On the other hand, if excessive oil is supplied for some reason and the hydraulic pressure becomes somewhat higher than the specified value, When the plunger 7 descends to the valve lift maximum position, the oil 10 passes through the first passage portion 80A, the upper lift check groove 65, and the second passage portion 80B which form the oil discharge dedicated passage 80, and the oil 10 The check valve 71 is opened by the pressure of 10, the excess oil is quickly discharged, and the hydraulic pressure becomes the specified value. Thus, in this embodiment, the amounts of the oil 10 inside the first and second cylinders 2 and 3 and the hose 4 are always kept substantially constant.

As described above, according to this embodiment,
By using one laminated piezoelectric element 56 as an actuator, the intake valves 58 of the cylinders (# 1, # 2, # 3) are
Since the A, 58B, and 58C can be driven to open and close without overlapping, if the valve device of the exhaust system is provided with the same structure, the intake air 6 is absorbed by the two laminated piezoelectric elements 56.
It is possible to smoothly drive a total of 12 valves, 6 valves and 6 exhausts, and it is possible to significantly reduce the number of actuators, thereby reducing weight and cost, and controlling valve opening and closing. It has the effect of being easy. Further, in the above-described embodiment, since the laminated piezoelectric element 56 as an actuator is provided at a place distant from the engine, the vibration of the engine hardly affects the laminated piezoelectric element, and the intake by the laminated piezoelectric element 56 is small. The reliability of the valve opening / closing operation is improved, and since the laminated piezoelectric element 56 is not provided in the cylinder head portion, the weight of the cylinder head can be reduced accordingly. Further, in the above embodiment, the opening / closing timing of the intake valve and the like can be controlled by the ECU 50 according to the operating condition of the engine and at a desired timing, and the opening / closing timing of the intake valve can be changed by changing the soft air program of the ECU. It can be easily changed and set, and the displacement of the laminated piezoelectric element 56 is amplified to drive the intake valve, and the intake valve is opened and closed by hydraulic pressure. The smooth operation of the intake valve can be ensured even when the engine is running at high speed, and further, the upper lift check groove 65, the lower lift check groove 66, the fluid replenishment dedicated passage 70, and the fluid discharge provided in the plunger 57. By the action of the dedicated passage 80,
Since the amount of oil inside is always kept almost constant, even if the oil leaks from the oil seal part over time or if excessive oil is temporarily supplied for some reason, the valve lift The amount can be kept constant, and the same good valve operating conditions as in the initial stage can be maintained for a considerably long period of time, which is effective in reducing intake performance due to defective valve operation over time. Can be suppressed.

In the above embodiment, the case where the present invention is applied to a three-cylinder, four-valve engine is illustrated, but the present invention is not limited to this, and when there are a large number of cylinders or three cylinders.
Even in the case of valves and 5 valves, the present invention can be applied by appropriately combining cylinders and intake / exhaust valves that do not overlap. Further, in the above-described embodiment, the case where the laminated piezoelectric element is used as the actuator is illustrated, but the present invention is not limited to this, and a solenoid or a conventional camshaft may be used as the actuator.

[0022]

Since the present invention is constructed and functions as described above, according to this, the cylinders for each cylinder are alternately and alternately communicated with the control main pipe by the hydraulic distributor, and the respective communication times are set. Since the actuator drives the first piston back and forth once within the cylinder, it is possible to sequentially open and close the intake valves or the exhaust valves of the plurality of cylinders by one actuator without overlapping. If there are multiple intake and exhaust valves in each cylinder,
The number of actuators can be significantly reduced, which can significantly reduce weight and cost.
Further, it is possible to provide an unprecedented excellent engine valve operating device in which the valve opening / closing control is simplified.

[Brief description of drawings]

FIG. 1 is a diagram schematically showing an overall configuration of an embodiment of the present invention.

FIG. 2 is a diagram for specifically explaining the attachment and internal structure of a second cylinder 3A of FIG.

3 is a schematic cross-sectional view of the hydraulic distributor of FIG.

FIG. 4 is a diagram for explaining the operation of the embodiment of FIG.

[Explanation of symbols]

 1 Valve Operating Device 2 First Cylinder 3A, 3B, 3C, 3D, 3E, 3F Second Cylinder 4A, 4B, 4C Cylinder-specific Pipe 15 Control Main Pipe 20 Hydraulic Distributor 53 First Piston 56 Stack as Actuator Piezoelectric element 58A, 58B, 58C Intake valve

Claims (1)

[Claims] 1. A first cylinder provided outside the engine and provided with a first piston slidably along the longitudinal direction thereof, and an intake valve or an exhaust valve of each cylinder of the engine along the longitudinal direction thereof. A plurality of second cylinders each of which is reciprocally movable, and an actuator that repeatedly reciprocally drives the front air first piston in its sliding direction, and the first cylinder is provided with a control main pipe via the control main pipe. A plurality of hydraulic distributors are connected to the hydraulic distributor, which are alternately and alternately communicated with the control main pipe by the hydraulic distributor at predetermined time intervals longer than the reciprocating time of the first piston. An engine valve operating system characterized in that one end of each pipe for each cylinder is connected, and the second cylinder is collectively connected for each cylinder to the other end of each pipe for each cylinder.