KR101083613B1 - Engine valve device - Google Patents

Abstract

Even an engine valve device having a variable opening / closing operation of a valve can be used to provide an engine valve device capable of following a high-speed rotation of an engine and changing an engine valve operation that can be efficiently operated. The intake valve 3 which opens and closes the intake port by the pressing force and the pressing force of the valve spring, the piston 23 movable in the same direction as the intake valve 3, and the piston 23 are housed so as to be able to move the inside thereof. A supply pipe passage 21d in communication with the cylinder 22, the hydraulic actuator 20 composed of the piston 23 and the cylinder 22, and the pressure chamber constituted by the piston 23 and the cylinder 22 And an accumulator 50 for accumulating the hydraulic oil flowing out from the pressure chamber through the supply pipe passage 21d, and controlling electromagnetic flow to control the flow of the hydraulic oil between the pressure chamber and the accumulator 50. Has a bracket 30, the electromagnetic on-off valve 30 was placed on the oil supply pipe between the hydraulic actuator 20 and the accumulator 50.

Engine valve unit

Description

Engine valve device {ENGINE VALVE DEVICE}

TECHNICAL FIELD This invention relates to an engine valve apparatus. It is related with the technique which makes the operation | movement of an engine valve apparatus variable.

FIG. 7 is a side sectional view showing a configuration of a known engine valve device, and FIG. 8 is a circuit diagram showing a configuration of a fluid circuit of the engine valve device shown in FIG. 7. As shown in FIG. 7, the engine valve device 100 is configured to maintain the open state of the intake valve 103 through the rocker arm 102 by the fluid actuator 101. As shown in FIG. 8, the engine valve device 100 includes a fluid actuator 101 following the rocker arm 102 and a direction control valve for preventing the outflow of fluid from the fluid actuator 101 at a predetermined timing. 105 and a fluid source for supplying fluid to the directional control valve 105, the directional control valve 105 prevents the outflow of the fluid from the fluid actuator 101 at a predetermined timing, whereby the fluid actuator 101 Can act on the rocker arm 102 to maintain the open state of the intake valve 103. The fluid source used in this way is a part of the lubrication unit 107 which accompanies an engine and supplies lubricating oil to an engine as shown in FIG. 8, for example, and can supply pressurized oil of about 210 KPa-620 KPa. On the other hand, the lubrication unit 107 accompanying the engine may form a pump separately, and may supply 10 MPa-35 MPa of pressurized oil to the direction control valve 105 (for example, refer patent document 1).

Patent Document 1: Japanese Unexamined Patent Publication No. 2003-328715

DISCLOSURE OF INVENTION

Problems to be Solved by the Invention

However, as described above, when a part of the lubrication unit 107 attached to the engine is used as a fluid source, when the pressurized oil of 210 KPa to 620 KPa is supplied to the direction control valve 105, the rotation of the engine is high speed, for example. For example, when it exceeds 1000 rpm, the piston 106 cannot follow the opening / closing operation of the intake valve 103. For this reason, the piston 106 cannot reach a predetermined position and the intake valve cannot be opened in a desired opening degree. On the other hand, when the pump is formed separately from the lubrication unit 107 attached to the engine and the pressurized oil of 10 MPa to 35 MPa is supplied, the engine becomes large and the cost of the engine cannot be largely increased. Moreover, whenever the fluid actuator 101 acts, it is supplied from the lubrication unit 107 attached to the engine and discharged, so that energy loss increases.

SUMMARY OF THE INVENTION The present invention has been made in view of the above, and even an engine valve device in which the operation is variable by utilizing a part of a lubrication unit attached to the hydraulic source, can follow high speed rotation of the engine and can be operated efficiently. It is an object to provide an engine valve device.

Means to solve the problem

In order to solve the above-described problems and achieve the object, the engine valve device according to the present invention includes a cam that rotates in conjunction with a crankshaft, a rocker arm that cooperates with the movement of the cam, a rocker arm, and a spring to act. An engine valve device having an intake valve for opening and closing an intake port, comprising: a piston movable in the same direction as the intake valve, a cylinder accommodated so that the piston can move inside, a hydraulic actuator comprising the piston and the cylinder And hydraulic pressure lines communicating with the pressure chamber constituted by the piston and the cylinder, accumulating means for accumulating the hydraulic oil discharged from the pressure chamber through the hydraulic lines, and flow of hydraulic oil between the pressure chamber and the pressure accumulating means. It has an electromagnetic on-off valve for controlling the hydraulic actuator and the hydraulic pipe and Group constituting the hydraulic circuit to the pressure accumulator unit and the electromagnetic on-off valve, and the electromagnetic on-off valve is characterized in that arranged on the hydraulic pipe line between said accumulator means and said hydraulic actuator.

Moreover, the engine valve apparatus which concerns on this invention is an engine valve provided with the cam which rotates in conjunction with a crankshaft, the rocker arm which cooperates with the movement of a cam, and the intake valve which a rocker arm and a spring act and open and close an intake port. In the apparatus, the hydraulic actuator is operated by opening and closing movement of the intake valve, and when the hydraulic oil is sealed in the pressure chamber, the hydraulic actuator which prevents the closing movement of the intake valve in the open state, and the intake valve is closed movement. Accumulate the hydraulic oil flowing out of the pressure chamber of the hydraulic actuator, and when the intake valve is moved open, accumulating means for supplying hydraulic oil to the pressure chamber of the hydraulic actuator, and electromagnetic control for controlling the outflow of the hydraulic oil from the hydraulic actuator to the accumulating means. An on-off valve to constitute a hydraulic circuit, and the electromagnetic on-off valve is connected to the hydraulic actuator and the shaft. And it characterized in that formed between the means.

Moreover, this invention is equipped with the hydraulic fluid supply means which supplies hydraulic oil to the said hydraulic circuit in the said invention. It is characterized by the above-mentioned.

In addition, the present invention is characterized in that, in the above invention, the hydraulic oil supply means is a lubrication unit that accompanies the engine and supplies lubricating oil to the engine.

Moreover, in this invention, in the said invention, the auxiliary pipe path which allows the outflow of hydraulic fluid to a pressure storage means from a pressure chamber of a hydraulic actuator is further formed, and the said auxiliary pipe path follows the intake valve which moves to a closing direction. And a port that opens when the piston position of the hydraulic actuator is in a predetermined section.

Further, in the above invention, a check valve is provided between the hydraulic oil supply means and the hydraulic circuit to supply hydraulic oil from the hydraulic oil supply means to the hydraulic circuit only when the hydraulic pressure of the hydraulic circuit is smaller than the hydraulic pressure of the hydraulic oil supply means. It is characterized by one.

Moreover, in the said invention, the pressure chamber of the said hydraulic actuator was comprised by the aspect which buffers the impact at the time of closing of an intake valve, It is characterized by the above-mentioned.

In addition, the present invention, in the above invention, the push rod interposed between the cam and the rocker arm, and transmits the movement from the cam to the rocker arm, and the elastic support means elastically supported in the direction in which the rocker arm is in close contact with the push rod Characterized in that provided.

Effects of the Invention

The engine valve device which concerns on this invention accumulate | stores the hydraulic fluid which flowed out from the pressure chamber of a hydraulic actuator, when the intake valve was closed-closed, and accumulate means which supplies hydraulic oil to the pressure chamber of a hydraulic actuator, when the intake valve is moved openly. And an electromagnetic on / off valve for controlling the outflow of the hydraulic oil from the hydraulic actuator to the accumulator means and constitutes a hydraulic circuit, and since the electromagnetic on / off valve is formed between the hydraulic actuator and the accumulator means, the intake valve is opened with good accuracy. In order to achieve this, the engine can follow the high-speed rotation of the engine and can operate efficiently.

Moreover, since the lubrication unit which accompanies an engine and supplies lubricating oil to an engine supplies hydraulic oil to a hydraulic circuit, the engine valve apparatus which concerns on this invention does not need to provide an oil pump separately from the lubrication unit accompanying an engine, and There is no need to increase the size of the engine, and the cost increase of the engine can be suppressed.

BRIEF DESCRIPTION OF THE DRAWINGS It is a conceptual diagram which shows the engine valve apparatus which concerns on embodiment of this invention.

It is a schematic diagram which shows the effect | action of the engine valve apparatus shown in FIG. 1, and is a figure which shows the closed state of an intake valve.

It is a schematic diagram which shows the effect | action of the engine valve apparatus shown in FIG. 1, and is a figure which shows the whole open state of an intake valve.

It is a schematic diagram which shows the effect | action of the engine valve apparatus shown in FIG. 1, and is a figure which shows the closed state of the intake valve.

It is a schematic diagram which shows the effect | action of the engine valve apparatus shown in FIG. 1, and is a figure which shows the state in which the intake valve was closed to predetermined opening degree.

It is a schematic diagram which shows the effect | action of the engine valve apparatus shown in FIG. 1, and is a figure which shows the whole closed state of an intake valve.

3 is a hydraulic circuit diagram of the engine valve device shown in FIG. 1.

It is a figure which shows the relationship between the cam rotation angle and the valve lift amount in the intake stroke of the engine valve apparatus shown in FIG.

FIG. 5 is a flowchart for explaining the control of the engine valve device shown in FIG. 1. FIG.

FIG. 6 is a timing chart illustrating control timing of the engine valve device shown in FIG. 1.

7 is a side sectional view showing a configuration of a known engine valve device.

FIG. 8 is a circuit diagram showing a configuration of a fluid circuit of the engine valve device shown in FIG. 7.

Description of the Related Art [0002]

1: engine valve unit

2: intake port

3: intake valve

3a: valve part

3b: stem

4: valve spring

5: cross head

9: rocker arm

9a: Pressurization part

9b: operating part

9c: home

13: push rod

14: tappet arm

15: return spring

18: cam

20: hydraulic actuator

21: block

21a: recessed portion

21b: the first pipeline

21c: second duct

21d: supply pipe

21e: outlet pipe

22 cylinder part

22a: small diameter room

22b: large diameter room

22b1: oil groove

23: piston

23a: piston part

23b: buffer part

23b1: vertical groove

23c: rod part

24: gap sensor

30: electromagnetic on / off valve

40: engine control unit (ECU)

50: accumulator

52: accumulator

55 cylinder

56: plunger

57: compression spring

60: hydraulic circuit

61: lubrication unit attached to the engine

62: check valve

63: relief valve

64: oil pan

CH: cylinder head

Best Mode for Carrying Out the Invention

EMBODIMENT OF THE INVENTION Below, the engine valve apparatus which concerns on embodiment of this invention is demonstrated in detail based on drawing. In addition, this invention is not limited by this embodiment.

1 is a conceptual diagram showing an engine valve device according to an embodiment of the present invention, FIG. 2 is a schematic diagram showing the operation of the engine valve device shown in FIG. 1, FIG. 3 is a hydraulic circuit diagram of the engine valve device shown in FIG. 1 is a diagram illustrating a relationship between a cam rotation angle and a valve lift amount in an intake stroke of the engine valve device shown in FIG. 1, FIG. 5 is a flowchart illustrating the control of the engine valve device shown in FIG. 1, and FIG. 6 is shown in FIG. 1. It is a timing chart explaining control timing of an engine valve apparatus.

The engine valve device 1 according to the embodiment of the present invention is applied to an engine valve device of a diesel engine of four cycles.

The diesel engine has a cylinder block and a cylinder head CH. The cylinder block is provided with the cylindrical cylinder which makes it possible to slide the engine piston EP to an up-down direction.

The cylinder head is provided with a pair of intake ports 2 which are inserted through the cylinder and a pair of exhaust ports not shown. In each intake port 2, the intake valve 3 moves up and down in FIG. 1, and is arrange | positioned so that the intake port 2 may be closed or opened, and the exhaust valve which is not shown in each exhaust port is provided up and down Are arranged to move in the direction and to close or open the exhaust port.

The intake valve 3 and the exhaust valve are umbrella shaped poppet-type valves, and a stem for sliding the cylinder head CH and a valve portion (umbrella-shaped portion) 3a for closing the intake port 2 and the exhaust port ( Bar part) 3b.

The valve spring 4 is attached to the stem 3b of the intake valve 3 inserted through the intake port 2, and the valve portion 3a of the intake valve 3 closes the intake port 2. It is elastically supported in the direction. Similarly, a valve spring (not shown) is attached to the stem of the exhaust valve through which the exhaust port is inserted, and the valve portion of the exhaust valve is elastically supported in the direction of closing the exhaust port.

Above the cylinder head CH, the T-shaped cross head 5 is provided in view of simultaneously pressing the stem ends of the pair of intake valves 3 simultaneously. The cross head 5 is guided to the shaft 6 formed in parallel with the movement direction of the intake valve 3 and the exhaust valve, and can be lifted up and down in FIG. Therefore, when the crosshead 5 is lowered, the crosshead 5 pressurizes the stem ends of the pair of intake valves 3 and resists the elastic support force of the valve spring 4 to open the intake valves 3. do.

One arm 5a (left arm in FIG. 1) of the crosshead 5 is provided with an adjustment screw 7 for adjusting the intake valve 3 and the crosshead 5 to come into close contact with each other. The adjustment screw 7 is helically advanced with respect to the crosshead 5, and adjusts the gap with one intake valve 3 (intake valve on the left side in FIG. 1) of the pair of intake valves 3. Can be. For example, it is possible to adjust so that the other intake valve 3 opens the intake port 2 and the one intake valve 3 opens the intake port 2. The lock nut 8 is spirally coupled to the adjustment screw 7, and the adjustment nut 7 can be prevented from loosening by bringing the lock nut 8 into close contact with the cross head 5 after the adjustment.

In FIG. 1 of the cross head 5, the rocker arm 9 is formed. The rocker arm 9 is rotatable with the rocker shaft 10 as an axis, and has one end portion (the left end portion in FIG. 1) forming a pressing portion 9a for pressing the cross head 5, and the other end portion. (The right end part in FIG. 1) forms the operation part 9b. The pressing portion 9a of the rocker arm 9 can press the substantially center portion of the cross head 5. Therefore, when the rocker arm 9 rotates in the counterclockwise direction in FIG. 1, the pressurizing portion 9a of the rocker arm 9 presses the cross head 5, and the intake valve 3 moves to the intake port ( 2) Open. On the other hand, when the rocker arm 9 rotates clockwise in FIG. 1, the intake valve 3 closes the intake port 2 by the elastic support force of the valve spring 4, and the crosshead 5 To increase). In the center of the pressing portion 9a, a groove 9c is formed in a U-shape in plan view.

The adjusting screw 11 which adjusts the clearance gap of the press part 9a and the crosshead 5 is spirally engaged with the operation part 9b of the rocker arm 9. As shown in FIG. The adjusting screw 11 has a hemispherical shape at one end, and a male screw is formed at the other end. The lock nut 12 is spirally coupled to the adjusting screw 11 spirally coupled to the other end of the rocker arm 9, and the adjusting screw 11 is brought into close contact with the rocker arm 9. It is possible to prevent loosening.

The hemispherical one end of the adjustment screw 11 is accommodated in one end of the push rod 13. A hemispherical recess 13a is formed in one end of the push rod 13 to accommodate one end having a hemispherical shape of the adjustment screw 11.

The push rod 13 rotates the rocker arm 9 counterclockwise in FIG. 1, and as shown in FIG. 2, the other end 13b of the push rod 13 is a tappet arm 14. It is accommodated in the push rod accommodating part 14a formed above the arm part of the.

As shown in FIG. 1, the return spring 15 is constructed between the operation part 9b of the rocker arm 9, and the cylinder head CH. The return spring 15 elastically supports the rocker arm 9 in the clockwise direction in FIG. 1, and maintains the state where the one end of the adjustment screw 11 is accommodated in the recess 13a of the push rod 13. can do. In addition, the return spring 15 may just support the rocker arm 9 clockwise in FIG. 1, and may be a torsion coil spring wound around the rocker shaft 10. In this case, one end of the coil spring is fixed to the rocker arm 9 and the other end is fixed to the cylinder head CH.

As shown in FIG. 2, the tappet arm 14 is mounted so as to be rotatable with the tappet shaft 16 as an axis. Therefore, when the tappet arm 14 rotates clockwise in FIG. 2, the tappet arm 14 pushes up the push rod 13 to cause the rocker arm 9 to rotate counterclockwise in FIG. 2. .

Under the arm part of the tappet arm 14, the roller follower 17 is attached so that it may rotate freely. Below the roller follower 17, the cam 18 which roll-contacts the said roller follower 17 is formed so that rotation is possible. The cam 18 rotates in association with the crankshaft (not shown) of the engine and, via the tappet arm 14, the push rod 13, the rocker arm 9 and the cross head 5, the intake valve 3. Is moved (lifted) to open the intake port 2. Therefore, the opening timing of the intake port 2 and the valve lift amount of the intake valve 3 are controlled by the outer shape (cam profile) of the cam 18. The valve lift amount is said to lift in the direction of opening in the closing time 0, and takes a positive value at that time.

The crankshaft is connected with the other end of the cone rod which connected one end to the engine piston EP which slides in a cylinder. Therefore, the intake valve 3 can be opened and closed in the intake stroke, and the intake valve 3 can be closed in the compression stroke, the explosion stroke, and the exhaust stroke.

As shown in FIG. 1, the hydraulic actuator 20 is formed above the crosshead 5. The hydraulic actuator 20 is arranged such that the distal end of the rod 23c of the piston 23 abuts against the cross head 5 and is interlockable with the operation of the cross head 5, and crosses at a predetermined timing. The head 5 is pressurized and the open state of the intake valve 3 is maintained regardless of the operation of the cam 18, the tappet arm 14, the push rod 13 and the rocker arm 9 described above. It is possible.

The hydraulic actuator 20 applied to this embodiment is single-acting, and the cylinder part 22 is integrally formed in the block 21, and the electromagnetic opening / closing valve 30 can be accommodated.

The block 21 is provided with a supply pipe line 21d in communication with the output port 30b of the electromagnetic on-off valve 30. Moreover, the 1st pipe line 21b which communicates with the output port 50a of the accumulator 50 mentioned later is formed. The first conduit 21b communicates with the input port 30a of the electromagnetic on-off valve 30 and the outflow conduit 21e described later by the second conduit 21c.

The cylinder part 22 is formed with the cylindrical small diameter chamber 22a and the large diameter chamber 22b which comprise a pressure chamber. One end of the large diameter chamber 22b is opened so that the piston 23 can be inserted, and is closed by the piston 23. At the other end of the large diameter chamber 22b, the small diameter chamber 22a coincides with the axis of the large diameter chamber 22b, and is formed so that it may communicate. The small diameter chamber 22a communicates with the supply pipe passage 21d. A step 22c is formed at the boundary between the large diameter chamber 22b and the small diameter chamber 22a.

An oil groove 22b1 is formed in a predetermined portion of the large diameter chamber 22b. The oil groove 22b1 is provided with the outflow pipe path 21e in communication with the second pipe path 21c.

The cylinder part 22 accommodates the piston 23 which slides in the axial direction (up-down direction in FIG. 1) of these large diameter chamber 22b and the small diameter chamber 22a. The piston 23 has the piston part 23a, the shock absorbing part 23b, and the rod part 23c. The piston part 23a is a part which slides the large diameter chamber 22b of the cylinder part 22. As shown in FIG. The buffer part 23b is a part accommodated in the small diameter chamber 22a of the cylinder part 22, and is formed in the axial end of the piston part 23a (above the piston part in FIG. 1). The shock absorbing portion 23b can buffer the shock at the time of closing the intake valve 3 by interaction with the small diameter chamber 22a of the cylinder portion 22, and in this sense, the pressure chamber has an intake valve ( It is comprised in the aspect which buffers the shock at the time of occlusion of 3).

Specifically, it has a buffer shape which buffers the shock at the time of the blockage of the intake valve 3 (at the time of seating of the intake valve 3) to the buffer part 23b. The buffer shape is, for example, a plurality of longitudinal grooves 23b1 (four longitudinal grooves in the present embodiment) formed from the outer circumferential source of the buffer portion 23b toward the tip, and the buffer portion 23b is a small diameter chamber ( When it is accommodated in 22a), the hydraulic oil that collects at the upper edge of the large diameter chamber 22b flows out through the longitudinal grooves 23b1, thereby alleviating the impact when the shock absorbing portion 23b is accommodated in the small diameter chamber 22a. You can. As a result, the shock at the time of the occlusion of the intake valve 3 associated with the piston 23 of the hydraulic actuator 20 is buffered and destroyed by the impact when the valve portion 3a of the intake valve 3 is seated. Can be prevented.

In addition, the buffer shape is not limited to the longitudinal groove 23b1, For example, you may form the buffer part 23b in the taper shape which becomes taper gradually toward the front-end | tip from a base. Further, the small diameter chamber 22a may be formed in a tapered shape that gradually thickens from the bottom toward the large diameter chamber 22b. The rod part 23c is a part which advances to the exterior from the cylinder part 22, and has a stage separate from the shock absorbing part 23b in the axial direction of the piston part 23a (the piston part 23a in FIG. 1). It is formed below). The rod portion 23c has a tapered shape formed in a tapered shape from the source toward the tip, and passes through the groove 9c formed in the pressing portion 9a of the rocker arm 9 to pass through the rocker arm ( It is possible to press the crosshead 5 without interfering with 9). Therefore, the rod part 23c can press the crosshead 5 independently of the rocker arm 9.

The gap sensor (gap measuring means) 24 is formed in the side of the rod part 23c of the piston 23. The gap sensor 24 measures the gap between the rod portion 23c and the gap sensor 24, and is connected to the engine control unit (ECU) 40. The gap sensor 24 can measure the clearance gap with the rod part 23c by measuring an eddy current, for example. The engine control unit 40 can monitor the operation | movement of the hydraulic actuator 20 by monitoring the clearance gap with the rod part 23c which the gap sensor 24 measured. Specifically, the gap decreases when the rod part 23c advances from the cylinder part 22, and the gap increases when the rod part 23c enters the cylinder part 22, so that the hydraulic pressure is monitored by monitoring the gap. The operation of the actuator 20 can be monitored.

The electromagnetic opening / closing valve 30 is accommodated in the recess 21a of the block 21. The electromagnetic on-off valve 30 is a two-port electromagnetic on-off valve having an input port 30a and an output port 30b. The input port 30a communicates with the second conduit 21c of the block 21, and the output port 30b communicates with the supply line 21d of the block 21. The electromagnetic on-off valve 30 has a spring and a solenoid not shown in addition to the spool 31 inside. In the normal state, the electromagnetic shut-off valve 30 presses the spool 31 to communicate with the input port 30a and the output port 30b. When the solenoid is excited, the electromagnetic shut-off valve 30 resists the elastic support force of the spring and the spool 31 This interrupts the communication state between the input port 30a and the output port 30b. Therefore, the electromagnetic on / off valve 30 can be switched between the hydraulic oil supply / discharge state and the hydraulic oil shutoff state.

Therefore, when hydraulic fluid is supplied to the supply pipe line 21d formed in the block 21 via the first pipe line 21b and the second pipe line 21c formed in the block 21 and the electromagnetic on / off valve 30, The operating oil is supplied to the large diameter chamber 22b via the small diameter chamber 22a. Then, hydraulic oil acts on the piston part 23a of the piston 23, and the piston 23 is pushed out of the cylinder part 22 (falling in FIG. 1), and the rod part 23c moves downward in FIG. Advance. Then, when the solenoid of the electromagnetic switching valve 30 is excited, the communication state of the input port 30a and the output port 30b is interrupted | blocked. In this state, when the rod part 23c is pushed up to the cylinder part 22 side (upward in FIG. 1), the piston part 23a of the piston 23 communicates with the outflow pipe path 21e of the block 21. The piston 23 is pushed into the cylinder portion 22 until the oil groove 22b1 to be closed is closed, and the working oil is sealed in the small diameter chamber 22a and the large diameter chamber 22b. At this time, the piston 23 is stopped by the hydraulic oil sealed in the small diameter chamber 22a and the large diameter chamber 22b, and stops.

Thereafter, when the solenoid of the electromagnetic on-off valve 30 is demagnetized, the input port 30a and the output port 30b are brought into communication again. When the rod part 23c of the piston 23 is pushed up to the cylinder part 22 side (upward in FIG. 1) in this state, the piston 23 raises and the supply pipe line 21d of the block 21 is raised. The hydraulic oil flows out from The hydraulic oil which has flowed out gradually flows out of the hydraulic actuator 20 via the output port 30b and the input port 30a of the electromagnetic opening / closing valve 30, the second conduit 21c and the first conduit 21b. do. Then, the shock absorbing part 23b of the piston 23 is accommodated in the small diameter chamber 22a of the cylinder part 22, and a series of operation | movement of the hydraulic actuator 20 is complete | finished.

The engine control unit 40 is connected to the electromagnetic switching valve 30. The engine control unit 40 controls the excitation timing and the excitation time of the electromagnetic on / off valve 30, and can arbitrarily control the electromagnetic on / off valve 30 in milliseconds (1/1000 second).

The output port 50a of the accumulator 50 is connected to the first conduit 21b of the block 21. The accumulator 50 constitutes accumulating means for accumulating hydraulic pressure, and the accumulator 50 according to the present embodiment is a mechanical accumulator.

As shown in FIG. 1, the accumulator 50 includes the above-described output port 50a, an output conduit 50b extending from the output port 50a, and an input conduit intersecting with the output conduit 50b ( 50c and the input port 50d communicated with the input line 50c. The input line 50c is in communication with the accumulator 52.

The accumulator 52 has a cylinder 55 formed in the accumulator 50 main body. The cylinder 55 communicates with the input pipe line 50c, and the hydraulic oil supplied from the input port 50d and the hydraulic oil supplied from the output port 50a can flow in. Inside the cylinder 55, a plunger 56 sliding in the axial direction of the cylinder 55 and a compression spring for elastically supporting the plunger 56 toward the bottom wall of the cylinder 55 (toward the left in the drawing). Has 57.

Therefore, even if hydraulic oil is supplied from the input port 50d of the accumulator 50, and hydraulic oil pressurizes the plunger 56 to the side (right side in FIG. 1), the plunger 56 is the elasticity of the compression spring 57. FIG. The hydraulic fluid flows out from the output port 50a because it cannot resist the bearing force. On the other hand, when hydraulic oil which flows out from the hydraulic actuator 20 and is supplied from the output port 50a of the accumulator 50 with higher pressure hydraulic oil than the hydraulic oil supplied from the input port 50d, the hydraulic oil is lateral to the plunger 56 (FIG. 1). In the right side), the plunger 56 moves to the side (right side in the drawing) against the elastic support force of the compression spring 57. At this time, hydraulic oil is stored (accumulated) in the accumulator 52.

These hydraulic actuators 20, the electromagnetic shut-off valve 30, and the accumulator 50 constitute the hydraulic circuit 60 as shown in FIG. The hydraulic circuit 60 can be supplied with a low pressure hydraulic oil from a lubrication unit 61 that is attached to the engine and supplies lubricant to the engine. The check valve 62 is arrange | positioned between the lubrication unit 61 accompanying the engine, and the hydraulic circuit 60. As shown in FIG. The check valve 62 supplies hydraulic oil to the hydraulic circuit 60 from the lubrication unit 61 accompanying the engine only when the hydraulic pressure of the hydraulic circuit 60 is smaller than the hydraulic pressure of the lubrication unit 61 accompanying the engine. No hydraulic oil flows from the hydraulic circuit 60 side to the lubrication unit 61 accompanying the engine.

Moreover, the relief valve 63 is formed between the check valve 62 and the hydraulic circuit 60 mentioned above. The relief valve 63 can discharge the hydraulic oil of the hydraulic circuit 60 to the oil pan 64 of an engine, when the hydraulic pressure of the hydraulic circuit 60 becomes higher than the preset pressure.

As described above, the engine control unit 40 to which the gap sensor 24 and the electromagnetic on-off valve 30 are connected has a TDC (Top Dead Center) sensor (cylinder discrimination signal output not shown) as shown in FIG. 6. Based on the cylinder discrimination signal (G signal) input from the means), it is to detect which cylinder engine piston EP is located at the top dead center. In addition, the engine control unit 40 calculates the rotational speed based on the rotational speed detection signal (Ne signal) input from a crank angle sensor (rotational speed detection signal output means) (not shown), and slows down the closing timing. When the engine piston EP of a cylinder (for example, cylinder "5" in FIG. 6) is located at top dead center, the pulse number of the rotation speed detection signal (square wave) is counted. When the number of pulses of the counted rotational speed detection signal reaches a preset VVA start setting pulse, the engine control unit 40 turns on the VVA start signal, and excites the electromagnetic opening / closing valve 30 by the predetermined VVA holding time Tw. It is supposed to be.

According to the engine valve apparatus 1 provided with the hydraulic circuit 60 mentioned above, hydraulic fluid is supplied to the hydraulic circuit 60 from the lubrication unit 61 accompanying the engine by starting an engine. Specifically, the working oil is supplied in the order of the accumulator 50, the electromagnetic closing valve 30, and the hydraulic actuator 20 via the check valve 62. Therefore, hydraulic fluid is filled in the electromagnetic on / off valve 30 and the hydraulic actuator 20.

Then, when the engine is operated, power is transmitted in the order of the cam 18, the tappet arm 14, the push rod 13, the rocker arm 9, and the cross head 5 in association with the crankshaft of the engine, In the intake stroke of the engine, the intake port 2 is opened and closed by the intake valve 3, and the intake port 2 is closed by the intake valve 3 in the compression stroke, the explosion stroke, and the exhaust stroke of the engine. .

In the compression stroke, the explosion stroke, and the exhaust stroke of the engine, as shown in FIG. 2A, the intake valve 3 closes the intake port 2 by the elastic bearing force of the valve spring 4. The rotation angle of the cam 18 and the valve lift amount at this time have a relationship shown in the closed region of FIG. 4. That is, the valve lift amount has a relationship of zero regardless of the rotation angle of the cam 18.

When the intake stroke of the engine is started, power is transmitted from the cam 18 in the order of the tappet arm 14, the push rod 13, the rocker arm 9, and the cross head 5, and the intake valve 3 is The intake port 2 gradually opens by being lifted. At this time, the cam rotation angle and the valve lift amount have a relationship shown in the open action region of FIG. 4. In other words, the valve lift amount gradually increases with the increase in the rotation angle of the cam 18.

At this time, the rod portion 23c of the piston 23 crosses the hydraulic fluid stored in the accumulator 50 by gradually being supplied to the small diameter chamber 22a and the large diameter chamber 22b of the cylinder portion 22. It gradually advances while contacting the head 5 (downward in FIG. 1). Specifically, the hydraulic oil is supplied in the order of the electromagnetic opening / closing valve 30 and the hydraulic actuator 20. Here, when hydraulic oil is not stored in the accumulator 50, hydraulic oil is gradually supplied to the hydraulic circuit 60 from the lubrication unit 61 accompanying the engine via the check valve 62.

And when the valve lift amount becomes the maximum, as shown in FIG. 2B, the intake port 2 will be in a full open state.

Thereafter, as shown in FIG. 2C, the crosshead 5, the rocker arm 9, the push rod 13, and the tappet arm 14 are supported by the elastic support force of the valve spring 4 and the return spring 15. Following the cam 18, the intake valve 3 gradually closes the intake port 2. The cam rotation angle and the valve lift amount at this time have a relationship shown in the blockage action region in FIG. 4. That is, the valve lift amount gradually decreases with the increase in the rotation angle of the cam 18.

At this time, the piston 23 is gradually accommodated in the cylinder portion 22, and the working oil of the small diameter chamber 22a and the large diameter chamber 22b of the cylinder portion 22 is stored in the accumulator 50. Thus, the hydraulic actuator 20 has the function of a piston pump. Specifically, the working oil is stored in the accumulator 50 via the electromagnetic on / off valve 30 and the hydraulic actuator 20.

And as shown in FIG. 4, when the valve lift amount becomes minimum, ie, 0, as shown in FIG. 2-5, the intake valve 3 will be in the fully closed state.

On the other hand, in the blocking action region shown in FIG. 4, when the electromagnetic opening / closing valve 30 is excited, the spool 31 cuts off the communication state between the input port 30a and the output port 30b in response to the elastic support force of the spring. do. That is, the electromagnetic on / off valve 30 shifts from the hydraulic oil supply / discharge state to the hydraulic oil shutoff state. Then, the piston 23 is pushed into the cylinder part 22 until the piston part 23a of the piston 23 closes the oil groove 22b1 which communicates with the outflow line 21e of the block 21, Thereafter, the hydraulic oil is sealed in the small diameter chamber 22a and the large diameter chamber 22b of the cylinder portion 22. Therefore, the piston 23 is stopped by the hydraulic fluid sealed in the small diameter chamber 22a and the large diameter chamber 22b, and stops.

Then, the rod part 23c of the piston 23 pressurizes the crosshead 5, and as shown in FIG. 2D, the intake valve 3 continues to be opened by predetermined opening degree. That is, the closing timing of the intake port 2 by the intake valve 3 is delayed in the intake stroke. Since the oil groove 22b1 is arrange | positioned inside the cylinder part 22, and the piston part 23a is a mechanism which closes the oil groove 22b1, an open state can be maintained in the same opening degree. The cam rotation angle and the valve lift amount at this time have a relationship shown in the blockage delay region in FIG. 4. That is, even if the rotation angle of the cam 18 increases, it has a relationship which valve lift amount becomes constant.

Thus, even when the rod part 23c of the piston 23 pressurizes the crosshead 5, and the intake valve 3 has continued to the predetermined opening degree, the rocker arm 9 is the return spring 15 It is in close contact with the push rod 13 by the elastic support force of, and is controlled by the outer diameter shape (cam profile) of the cam 18. Accordingly, the push rod 13 does not fall off from the rocker arm 9, and a gap is generated between the crosshead 5 and the rocker arm 9.

When the electromagnetic on-off valve 30 is demagnetized after predetermined time passes, the input port 30a and the output port 30b will be in communication again. Therefore, the intake valve 3 gradually closes the intake port 2 by the elastic support force of the valve spring 4.

At this time, the crosshead 5 pressurizes the piston 23, and the piston 23 is gradually accommodated in the cylinder portion 22 again, and the small diameter chamber 22a and the large diameter chamber ( The operating oil of 22b) is stored in the accumulator 50.

And as shown in FIG. 4, when the valve lift amount becomes minimum, ie, 0, as shown in FIG. 2E, the intake port 2 will be in the fully closed state by the intake valve 3. As shown in FIG.

Thus, in order to delay the closing timing of the intake port 2 by the intake valve 3 in an intake process, the engine control unit 40 is a cylinder which slows the closing timing (as shown to FIG. 5 and FIG. 6). For example, when the engine piston EP of the cylinder "5" in FIG. 6 is located in top dead center (step S1: Yes), the count of the pulse number of a rotation speed detection signal is started (step S2). . When the number of pulses of the rotational speed detection signal reaches the preset VVA start setting pulse (step S3: Yes), the VVA start signal is turned on (step S4). In this way, when the VVA start signal is turned on, the electromagnetic opening / closing valve 30 is excited for the predetermined VVA holding time Tw (step S5). Then, by repeating such a cycle, it controls so that the blockage timing of the intake port 2 by the intake valve 3 may be delayed.

According to the engine valve apparatus 1 which concerns on embodiment of this invention mentioned above, when the electromagnetic shut-off valve 30 is closed, the piston 23 of the hydraulic actuator 20 is the oil groove 22b1 (outflow pipe path | route) 21e)) until the intake valve 3 is connected to the rocker arm 9 and the oil groove 22b1 communicating with the outlet pipe 21e is closed, the electromagnetic on / off valve 30 is opened. Since the open state of the intake valve 3 is maintained until the open state, the open state of the intake port 2 can be maintained at a predetermined opening degree without being influenced by the closing timing of the electromagnetic on / off valve 30.

As mentioned above, the engine valve apparatus which concerns on this invention is useful for the engine valve apparatus which makes the operation | movement of an engine valve variable, and is especially suitable for the engine valve of a diesel engine.

Claims (8)

A cam rotating in association with the crankshaft, With a rocker arm linked to the movement of the cam, An engine valve device having an intake valve for actuating a rocker arm and a spring to open and close an intake port, A piston movable in the same direction as the intake valve, A cylinder accommodated to move the piston therein; A hydraulic actuator comprising the piston and the cylinder, A hydraulic pipe communicating with a pressure chamber constituted by the piston and the cylinder; Accumulating means for accumulating the hydraulic oil flowing out of the pressure chamber through the hydraulic line; Has an electromagnetic on / off valve for controlling the flow of hydraulic oil between the pressure chamber and the pressure storage means, A hydraulic circuit is constituted by the hydraulic actuator, the hydraulic pipe, the accumulating means, and the electromagnetic on / off valve, And the electromagnetic on / off valve is disposed on a hydraulic line between the hydraulic actuator and the accumulator means. A cam rotating in association with the crankshaft, With a rocker arm linked to the movement of the cam, An engine valve device having an intake valve for actuating a rocker arm and a spring to open and close an intake port, A hydraulic actuator which is operated by the opening and closing movement of the intake valve and prevents the closing movement of the intake valve in the open state when the hydraulic oil is sealed in the pressure chamber; Accumulating means for accumulating the hydraulic oil flowing out of the pressure chamber of the hydraulic actuator when the intake valve is moved, and supplying hydraulic oil to the pressure chamber of the hydraulic actuator when the intake valve is opened; The hydraulic circuit is provided by the electromagnetic on / off valve for controlling the outflow of the hydraulic oil from the hydraulic actuator to the accumulator means, An engine valve device, wherein the electromagnetic on / off valve is provided between the hydraulic actuator and the accumulator means. The method according to claim 1 or 2, An engine valve device comprising: hydraulic oil supply means for supplying hydraulic oil to the hydraulic circuit. The method of claim 3, wherein The engine valve device, characterized in that the operating oil supply means is a lubrication unit that is supplied to the engine to supply lubricant to the engine. The method according to claim 1 or 2, Further forming an auxiliary conduit to allow the outflow of hydraulic fluid from the pressure chamber of the hydraulic actuator to the accumulator means, The auxiliary pipe passage has a port that opens when the piston position of the hydraulic actuator following the intake valve moving in the closing direction is in a predetermined section. The method of claim 3, wherein And a check valve for supplying hydraulic oil from the hydraulic oil supply means to the hydraulic circuit only when the hydraulic pressure of the hydraulic circuit is smaller than the hydraulic pressure of the hydraulic oil supply means. The method according to claim 1 or 2, An engine valve device comprising the pressure chamber of the hydraulic actuator in an aspect of buffering an impact when closing an intake valve. The method of claim 2, A push rod interposed between the cam and the rocker arm and transferring movement from the cam to the rocker arm, An engine valve device comprising an elastic support means elastically supported in a direction in which the rocker arm is in close contact with the push rod.

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