JPH06185327A - Valve system of engine - Google Patents

Abstract

PURPOSE:To stabilize lift amount switching performance of a valve system of an engine by providing a control means to enable an auxiliary valve to vary an effective lift amount of a valve to engage with the valve and to regulate or not to regulate a moving amount of the auxiliary valve. CONSTITUTION:Driving force of a cam 2 is transmitted to a suction valve only through a lifter 22. Between a retainer 51 arranged on a cylinder head 50 of an engine, a valve spring 44 is stretched. On a cylinder side opening end of a suction air passage 52, a suction air port 53 with a seat 54 is formed. An auxiliary valve 60 is arranged on the outer periphery of a large diametrical part 47 of a stem 41 of the suction valve 40, and a stepped part 48 of the stem 41 and a stepped part 62 of a stem 63 of the auxiliary valve 60 can be engaged with each other. By a control means, a moving amount of the auxiliary valve 60 is regulated or not regulated, and an engagement state of the suction valve 40 and the auxiliary valve 60 can be controlled. Consequently, when the moving amount of the auxiliary valve 60 is perfectly regulated and comes to be in a stopping state, an effective lift amount of the valve becomes maximum, and when the moving amount of the auxiliary valve 60 is not regulated, the effective lift amount of the valve becomes smaller.

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, which can control the effective lift amount of intake and exhaust valves, that is, the opening degree of each valve to an arbitrary variable amount, and can also perform variable cylinder control. It is possible.

[0002]

2. Description of the Related Art In an engine, the valve opening / closing timing of an intake / exhaust valve and the valve stroke are changed, the operation of the intake / exhaust valve and fuel supply are stopped, and the cylinder is deactivated (variable cylinder) to reduce fuel consumption and output. It is known to improve the

For example, the "variable valve timing mechanism" disclosed in Japanese Utility Model Publication No. 2-18247 will be described with reference to FIG. 17. The variable valve timing mechanism is attached to and detached from a seat 201 arranged at one end of an intake (exhaust) air passage 200. An intake (exhaust) air valve 202 is freely engaged, and the intake (exhaust) air valve 202 is opened and closed by a cam 203 via a shim 204 and a lifter 205.

The cam 203 has a high lift portion 203a and a low lift portion 203b, and each lift portion 203a, 203b.
The above-mentioned shim 204 intervenes in the lift amount transmission from any one of the above to the lifter 205. When the shim 204 is at the position shown in FIG. 18, the lift amount of only the high lift portion 203a acts on the lifter 205 so that the intake (exhaust) air valve 202 moves to the seat 20.
The air intake (exhaust) amount is relatively large and is relatively large from 1. On the other hand, when the shim 204 is in the position shown in FIG. 19, the lift amount of only the low lift portion 203b acts on the lifter 205 so that the intake (exhaust) air valve 202 is relatively small away from the seat 201 and the intake (exhaust) air is exhausted. The amount is relatively small.

Since the shim 204 receives a large force from the cam 203 and the valve spring 206 when the cam 203 is lifted, it is essential that the cam 203 is engaged with the shim 204 at the base circular portion 203c when the shim 204 is moved. It becomes a condition. Here, the amount of movement of the shim 204 is relatively large, and various problems are expected in improving the switching reliability between the lift portions 203a and 203b. Also, the cam 203
It itself has a complex shape, and various problems are expected to improve its durability.

[0006] Further, as a publicly known material of an engine having a variable valve timing, a variable lift and a variable cylinder mechanism, one described in a public relational material of "MIVEC Engine" published by Mitsubishi Motors Corporation, Public Relations Department, September 1992. There is.

[0007]

Therefore, in the present invention, it is necessary to stabilize the lift amount switching performance of the valve operating system of the engine.
This is a technical issue.

[0008]

The technical means of the present invention taken to solve the above-mentioned technical problem of the present invention is a valve, a seat disposed at one end of an intake / exhaust passage, and a seat. In a valve operating system of an engine having a valve spring for urging a valve in a seating direction and a cam for urging a valve in a direction of moving the valve away from a seat, a moving state of the valve is controlled by a control unit to determine an effective lift amount of the valve. A variable auxiliary valve is provided so that it can be engaged with the valve, and when the control means is in the first state, the movement amount of the auxiliary valve is restricted, and when the control means is in the second state, the auxiliary valve is That is, the amount of movement of the valve is not regulated.

[0009]

According to the above-mentioned technical means of the present invention, the movement amount of the auxiliary valve is regulated when the control means is in the first state,
When the control means is in the second state, it is not regulated and the effective lift amount of the valve is variably controlled.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments embodying the technical means of the present invention will be described below with reference to the accompanying drawings.

In general, at least one intake passage and one exhaust passage are connected to each cylinder of an engine, and an intake port and an exhaust port are formed at the cylinder-side open end of each passage. In the following first embodiment, the valve operating system 10 of the engine may be applied to at least one of the intake and exhaust valves, and in the following first embodiment, an example in which the application target is an intake valve will be described.

A valve operating system 10 for an engine according to a first embodiment of the present invention will be described with reference to FIGS. 1 to 6. The engine is generally called a direct drive type and drives a cam 21 fixed to a camshaft 20. The force is transmitted to the intake valve 40 only through the lifter 22 without passing through a rocker arm (not shown). Here, the plate 24 is provided on the upper end (the contact surface of the cam 21) of the cup-shaped body 23 of the lifter 22, and the stem 4 of the intake valve 40 is provided on the inner bottom surface of the body 23.
1 The upper end surface is in contact. A retainer 43 is provided at an upper end of the stem 41 via a cotter 42, and a valve spring 44 is stretched between the retainer 51 and a retainer 51 provided on a cylinder head 50 of the engine. Cylinder head 50
Is formed with an intake passage 52, and an intake port 53 having a seat 54 is formed at an opening end on the cylinder side thereof.

Seating surfaces 45 and 46 are formed on the intake valve 40. The seating surface 45 is separable from the seat 54, and the seating surface 46 is separable from the seat surface 61 of the auxiliary valve 60. When 46 is seated on the seat surface 61, they are not in close contact with each other and have a slight clearance, provided that the amount of this clearance is the position where the stepped portion 48 of the stem 41 and the stepped portion 62 of the stem 63, which will be described later, are formed. It can be set to 0 depending on the relationship). The auxiliary valve 60 is disposed on the outer circumference of the large diameter portion 47 of the stem 41 of the intake valve 40,
The stepped portion 48 of the stem 41 and the stepped portion 62 of the stem 63 of the auxiliary valve 60 are engageable. The stem seal 64 surrounds the upper end of the stem 63 and the outer periphery of the stem 40.
Is provided. A flange 65 extending in the outer peripheral direction is formed on the stem 63, and an auxiliary valve spring 66 is stretched between the retainer 43 and the flange 65. A guide 55 fitted in the hole of the cylinder head 50 is engaged with the outer periphery of the stem 63, and therefore the auxiliary valve 6
The stem 63 of 0 slides vertically in the hole of the guide 55, and the stem 41 of the intake valve 40 slides vertically in the hole of the stem 63. Reference numeral 56 represents a seal. The state shown in FIG. 4 (other than the state where the lifter 22 is engaged with the cam 21 at the base circle)
In addition, the space 68 formed above the stepped portion 48 of the stem 41 in the hole of the stem 63 acts as an air damper.

A cylinder 71 is formed in the cylinder head 50 in a direction perpendicular to the axial direction of the stem 41, and a piston 72 is slidably arranged in the cylinder 71. The piston 72 has a stepped portion 73, and a spring 74 is stretched between the stepped portion 73 and the outer peripheral surface of the guide 55 to urge the piston 72 toward the stopper 75.
A through hole 76 is formed substantially in the center of the stopper 75. The convex portion 77 of the piston 72 can be projected and retracted in the through hole 57 formed in the guide 55, and can be engaged with the concave groove 67 formed on the outer periphery of the stem 63 of the auxiliary valve 60. Reference numeral 58 represents a drain passage.

The left end side of the piston 72 in the cylinder 71 acts as a port 80. This port 80 is shown in Figure 3.
Communicating with one port of the three-way valve 81 of the hydraulic control circuit shown in
The other two ports of the three-way valve 81 communicate with the hydraulic pressure supply line 82 and the drain 83, respectively. Here, a hydraulic pump 84 is arranged on the hydraulic supply line 82. The operation of the three-way valve 81 is controlled by the control circuit 85.
Reference numeral 86 represents an engine oil pan. The hydraulic pressure control circuit and the cylinder 71 to the through hole 76 shown in FIG.

An engine valve operating system 1 having the above structure
At 0, since the hydraulic pump 84 does not generate hydraulic pressure when the engine is stopped, hydraulic pressure is not acting on the hydraulic port 80 regardless of the state of the three-way valve 81. Therefore, the urging force of the spring 74 causes the convex portion 77 of the piston 72 to move the stem 63 of the auxiliary valve 60, as shown in FIG.
Is not engaged with the concave groove 67 of. Then, when the engine is started, the hydraulic pump 84 starts to generate hydraulic pressure.
Here, various information such as the engine speed and the load is input to the control device 85, and the air amount required for the intake valve 40 is small immediately after the engine is started and when the engine is at a low speed or a low load. The effective lift amount may be relatively small. Therefore, when the cam 21 gives the maximum lift to the lifter 22, the respective components become the states shown in the right half of FIG. 4, and the intake / exhaust valve 40 (in FIG. 5, the engine valve operating device 10 of the intake / exhaust valve is The effective lift amount is shown in FIG. 5. That is, the control device 85 uses the three-way valve 84 to make the port 80 not communicate with the hydraulic pressure supply line 82 but only the drain 83. This state is the second state (L lift) of the control means, and the piston 72
Does not engage with the groove 67 as when the engine is stopped, and the movement of the auxiliary valve 60 is not restricted.

When the cam 21 is engaged with the lifter 22 at the base circle, the seating surface 45 of the intake valve 40 is seated by the urging force of the valve spring 44 as shown in FIG.
And the intake port 53 is closed, and the stepped portion 62 of the stem 63 of the auxiliary valve 60 is pushed up by the stepped portion 48 of the stem 41, and its seat portion 61 is slightly seated on the seating surface 46 of the intake valve 40. Sit with clearance. When the lift surface of the cam 21 begins to act on the lifter 22, the seating surface 45 of the intake valve 40 separates from the seat 54, and the intake valve 40 is pushed downward against the urging force of the valve spring 44. At the same time, the seating surface 46 of the intake valve 40
The auxiliary valve 60 also holds the auxiliary valve spring 6 so that a small clearance is maintained between the auxiliary valve 60 and the seat surface 61 of the auxiliary valve 60.
It is pushed down through 6. When the lift amount by the lift surface of the cam 21 becomes R1 shown in FIG. 5,
Since the flange 65 of the auxiliary valve 60 engages with the retainer 51 and both constitute a stopper mechanism, the auxiliary valve 60 cannot be pushed down by R1 or more, and when the lift amount exceeds R1, the intake valve 4
The seating surface 46 of 0 is separated from the seat surface 61 of the auxiliary valve 60. At this time, the auxiliary valve spring 66 moves the flange 6
The compression amount is increased while pressing 5. And
After the lift amount of the cam 21 exceeds the maximum, the intake valve 40 moves upward due to the urging force of the valve spring 44 as the lift amount decreases, and the lift amount of the cam 21 becomes R.
When returned to 1, the stepped portion 48 of the stem 40 is
3 push up the stepped portion 62, and the flange 65 becomes the retainer 5.
1, the seating surface 46 of the intake valve 40 is seated on the seat surface 61 of the auxiliary valve 60 with a slight clearance.
Further, when the lift amount of the cam 21 approaches 0, the intake valve 4
0 and the auxiliary valve 60 simultaneously move upward, and when the lift amount becomes 0, the seating surface 45 of the intake valve 40 seats on the seat 54. That is, when the lift amount of the cam 21 is between 0 and R1, one of the seating surfaces 45 and 46 of the intake valve 40 is seated on either the seat 54 or the seat surface 61, and the intake port 53 remains closed. The lift amount of the cam 21 is R1
From the maximum to the maximum, the seating surfaces 45 and 46 of the intake valve 40 are separated from either the seat 54 or the seat surface 61, and the intake port 53 is opened. Incidentally, R1
The height can be adjusted as appropriate by changing the formation position of the flange 65 and the thickness of the retainer 51.

On the other hand, at the time of high engine speed or high load, the required air amount becomes large, and the effective lift amount of the intake valve 40 must be relatively large. Therefore, when the cam 21 gives the maximum lift to the lifter 22, the respective constituent elements are in a state as shown in the left half of FIG.
The effective lift amount (shown in FIG. 6 when the valve operating device 10 of the engine is applied to both intake and exhaust valves) is as shown in FIG. That is, the control device 85 uses the three-way valve 84 to communicate the port 80 only with the hydraulic pressure supply line 82 and not with the drain 83. Therefore, the piston 72 moves to the right against the biasing force of the spring 74, and the convex portion 77 of the piston 72 engages with the concave groove 67 of the stem 63 through the through hole 57 of the guide 55. The oil pressure leaked from the port 80 to the outer peripheral side of the convex portion 77 via the outer peripheral surface of the piston 72 returns from the drain passage 58 to the oil pan 86. This state is the first state (H lift) of the control means, the piston 72 does not engage with the recessed groove 67 as when the engine is stopped, and the movement of the auxiliary valve 60 is not restricted. When supplying hydraulic pressure to the port 80, the lifter 22 moves the cam 2
Desirably during engagement with one base circle.

When the cam 21 is engaged with the lifter 22 at the base circle, it is the same as in the second state of the control means described above, and when the lift surface of the cam 21 begins to act on the lifter 22. The seating surface 45 of the intake valve 40 is separated from the seat 54, and the intake valve 40 is pushed downward against the biasing force of the valve spring 44. At this time, the piston 72
The convex portion 77 is engaged with the concave groove 67 of the stem 63, the auxiliary valve 60 cannot move upward or downward, and the auxiliary valve spring 66 is only compressed. That is, when the lift amount of the cam 21 is between 0 and the maximum, the seating surface 45 of the intake valve 40,
All of the members 46 are separated from either the seat 54 or the seat surface 61, and the intake port 53 is opened.

Table 1 below shows the states of various components of the engine valve operating system 10 of the first embodiment during L lift (second state of control means) and H lift (first state of control means). Shown together.

[0021]

[Table 1]

Next, the engine valve operating system 100 of the second embodiment of the present invention will be described with reference to FIGS. 7 to 13. The same parts as those of the first embodiment will be designated by the same reference numerals. Therefore, the description will be omitted. In the second embodiment described below, it is highly desirable to apply the engine valve operating system 10 to both intake and exhaust valves, and in the second embodiment below, only an example of an intake valve will be described.

Although the stem 63 of the auxiliary valve 60 does not have the flange 65 as in the first embodiment, it extends in the radial direction of the stem 63 at a position substantially the same height as the stepped portion 62, and the inside of the hole of the stem 63 ( A communication passage 161 that communicates the space 68) with the outside is formed. However, the communication passage 161 may be formed at the same position in the engine valve operating system 10 of the first embodiment.

Two pistons 17 are provided in the cylinder 71.
1, 172 are provided. The piston 171 has substantially the same shape as the piston 72 of the first embodiment, and has a stepped portion 173, a convex portion 174, and a through hole 175 in the center. The piston 172 includes a stepped portion 176, a stepped portion 177, a through hole 175.
It has a convex portion 178 and a concave portion 179 that can slide inside. A spring 180 is stretched between the stepped portion 173 and the outer peripheral surface of the guide 55, and urges the piston 171 in the direction in which the left end surface thereof engages with the stepped portion 177. A port 182 opens in a space 181 in which the spring 180 is stretched. On the other hand, a spring 183 is stretched between the stopper 75 and the bottom of the recess 179, so that the piston 1
72 is biased in the direction in which the stepped portion 177 engages with the left end surface of the piston 171. Stepped portion 17 of piston 172
A port 185 is opened in a space 184 between the piston 6 and the left end surface of the piston 171. The springs 180, 18
3 is a piston 171,1 at the time of 0, L, H lift which will be described later
The biasing force is adjusted appropriately so as to ensure the operating position of 72. Although the number of pistons is shown as two, any number of pistons may be used as long as it is at least two, and the effective lift amount of the intake valve 40 can be controlled in multiple stages as the number of pistons increases.

The port 182 communicates with one port of the three-way valve 191 of the hydraulic control circuit shown in FIG. 9, and the other two ports of the three-way valve 191 communicate with the hydraulic pressure supply line 82 and the drain 83, respectively. The port 185 communicates with one port of the three-way valve 192, and the other two ports of the three-way valve 192 communicate with the hydraulic pressure supply line 82 and the drain 83, respectively. 3-way valve 1
The operation of 91 and 192 is controlled by the control circuit 85. This hydraulic control circuit and piston 17 shown in FIG.
1, 172 and the like constitute the control means.

A valve operating system 1 for an engine having the above construction
At 00, since the hydraulic pump 84 does not generate hydraulic pressure when the engine is stopped, the three-way valves 191, 192
No hydraulic pressure is applied to the hydraulic ports 182 and 185 regardless of the state. However, due to the urging force of the springs 180 and 183, the protrusion 174 of the piston 171 is
As shown in FIG. 7, the convex portion 178 of the piston 172 does not engage with the concave groove 67 of the stem 63 of the auxiliary valve 60, but engages with the concave groove 67. Then, when the engine is started, the hydraulic pump 84 starts to generate hydraulic pressure. Immediately after the engine is started and when the engine is running at low speed or under low load, the amount of air required is small, and the effective lift amount of the intake valve 40 may be relatively small. Therefore, when the cam 21 gives the maximum lift to the lifter 22, the respective components are in a state as shown in FIG. 10, and the effective lift amount of the intake / exhaust valve 40 is as shown in FIG. 5 as in the first embodiment. Become. That is, the control device 85 uses the three-way valve 19
The ports 182 and 185 are not communicated with the hydraulic pressure supply line 82 by using 1,192, but only with the drain 83. This state is the first state- (L lift) of the control means, the concave groove 67 engages only with the convex portion 178 of the piston 172, and the movement of the auxiliary valve 60 is the same as when the engine is stopped. It is regulated as possible only within the range.

The protrusion 178 of the piston 172 has a groove 67 when the lifter 22 engages with the cam 21 at the base circle.
It is located at a substantially central portion in the height direction.

When the cam 21 is engaged with the lifter 22 at the base circle, the seating surface 45 of the intake valve 40 is seated by the urging force of the valve spring 44 as shown in FIG.
And the intake port 53 is closed, and the stepped portion 62 of the stem 63 of the auxiliary valve 60 is pushed up by the stepped portion 48 of the stem 41, and its seat portion 61 is slightly seated on the seating surface 46 of the intake valve 40. Sit with clearance. When the lift surface of the cam 21 begins to act on the lifter 22, the seating surface 45 of the intake valve 40 separates from the seat 54, and the intake valve 40 is pushed downward against the urging force of the valve spring 44. At the same time, the seating surface 46 of the intake valve 40
The auxiliary valve 60 also holds the auxiliary valve spring 6 so that a small clearance is maintained between the auxiliary valve 60 and the seat surface 61 of the auxiliary valve 60.
It is pushed down through 6. When the lift amount by the lift surface of the cam 21 becomes R1 shown in FIG. 5,
Since the convex portion 178 of the piston 172 engages with the upper end of the concave groove 67 and both constitute a stopper mechanism, the auxiliary valve 60 cannot be pushed down by R1 or more, and when the lift amount exceeds R1, the seating surface 46 of the intake valve 40 is reduced. Moves away from the seat surface 61 of the auxiliary valve 60. At this time, the auxiliary valve spring 66 increases the amount of compression.

After the lift amount of the cam 21 exceeds the maximum value, the valve spring 44 is reduced as the lift amount decreases.
When the intake valve 40 moves upward due to the urging force of the cam 21 and the lift amount of the cam 21 returns to R1, the stepped portion 48 of the stem 41 pushes up the stepped portion 62 of the stem 63, and the groove 67 The upper end is separated from the convex portion 178 of the piston 172,
The seating surface 46 of the intake valve 40 is seated with a slight clearance from the seat surface 61 of the auxiliary valve 60. Furthermore, the cam 21
Of the intake valve 40 and the auxiliary valve 6 when the lift amount of the
At the same time, 0 moves upward, and when the lift amount becomes 0, the seating surface 45 of the intake valve 40 seats on the seat 54. That is, when the lift amount of the cam 21 is between 0 and R1, one of the seating surfaces 45 and 46 of the intake valve 40 is seated on either the seat 54 or the seat surface 61, and the intake port 53 remains closed. While the lift amount of the cam 21 is between R1 and maximum, both the seating surfaces 45 and 46 of the intake valve 40 are separated from either the seat 54 or the seat surface 61, and the intake port 53 is opened.

The height of R1 can be appropriately adjusted by changing the height of the concave groove 67 or the like. On the other hand, when the engine is rotating at high speed or under high load, the required air amount is large, and the effective lift amount of the intake valve 40 must be relatively large. Therefore, when the cam 21 gives the maximum lift to the lifter 22, the respective components are in a state as shown in FIG. 11, and the effective lift amount of the intake / exhaust valve 40 is as shown in FIG. 6 as in the first embodiment. Become. That is, the control device 85 uses the three-way valve 191.
The port 182 is not communicated with the hydraulic pressure supply line 82, but is communicated with only the drain 83, and the three-way valve 192 is used to communicate the port 185 only with the hydraulic pressure supply line 82 and not with the drain 83. Therefore, the high hydraulic pressure in the space 184 moves the piston 171 to the right against the biasing force of the spring 180, and the convex portion 17 of the piston 171 moves.
4 engages with the groove 67 of the stem 63 through the through hole 57 of the guide 55. At the same time, the high hydraulic pressure in the space 184
The piston 172 is moved to the left against the biasing force of the spring 183, and the left end of the piston 172 moves to the stopper 75.
Engage with. This state is the first state- (H lift) of the control means, and the convex portion 174 of the piston 171 has the concave groove 67.
And the movement of the auxiliary valve 60 is restricted. When supplying the hydraulic pressure to the port 185, the lifter 22 moves the cam 2
Desirably during engagement with one base circle.

When the cam 21 is engaged with the lifter 22 at the base circle, it is the same as in the above-mentioned first state-of the control means, and the lift surface of the cam 21 starts to act on the lifter 22. And the seating surface 45 of the intake valve 40 is seated on the seat 54.
The intake valve 40 is pushed downward against the biasing force of the valve spring 44. At this time, the convex portion 174 of the piston 171 is engaged with the concave groove 67 of the stem 63, the auxiliary valve 60 cannot move upward or downward, and the auxiliary valve spring 66 is only compressed. That is, when the lift amount of the cam 21 is between 0 and the maximum, the seating surfaces 45 and 46 of the intake valve 40 are both seat 54 or seat surface 6.
The intake port 53 is in an open state apart from any one of the above.

Further, immediately after the engine is started, or when the engine power is excessively low at low engine speed or low load, the combustion in at least one cylinder of the multi-cylinder engine is stopped, that is, variable cylinder is used. Planned. In the stopped cylinder, when the cam 21 gives the maximum lift to the lifter 22, the respective constituent elements are in a state as shown in FIG. 12, and the effective lift amount of the intake / exhaust valve 40 is 0 as shown in FIG. That is, the control device 85 uses the three-way valve 19
The port 182 communicates only with the hydraulic pressure supply line 82 with 1 and does not communicate with the drain 83, and the port 185 does not communicate with the hydraulic supply line 82 with the three-way valve 192 but communicates only with the drain 83. Therefore, the high hydraulic pressure in the space 181 moves both the pistons 171 and 172 to the left against the biasing force of the spring 183, and the piston 1
The left end of 72 engages with the stopper 75, and the left end of piston 171 engages with the stepped portion 177. This state is the second state of the control means, and neither the convex portion 174 of the piston 171 nor the convex portion 178 of the piston 172 engages with the concave groove 67, and the movement of the auxiliary valve 60 is not regulated. The hydraulic pressure is preferably supplied to the port 182 while the lifter 22 is engaged with the base circle of the cam 21.

When the cam 21 is engaged with the lifter 22 at the base circle, the above-mentioned first state of the control means--,
Is the same as when the lift surface of the cam 21 is lifter 22.
When the seating surface 45 of the intake valve 40 is separated from the seat 54 and the intake valve 40 is pushed downward against the urging force of the valve spring 44, the seating surface 46 of the intake valve 40 is simultaneously pressed. The auxiliary valve 60 is also pushed downward via the auxiliary valve spring 66 so that the small clearance is maintained with the seat surface 61 of the auxiliary valve 60. Then, since there is nothing that restricts the downward movement of the auxiliary valve 60, the auxiliary valve 60 is similarly lifted during the entire period in which the intake valve 40 is lifted. That is, the intake port 53 remains closed regardless of the lift amount of the cam 21.

Tables 2 to 3 below show various kinds of L / H lift (first state of control means) and zero lift (second state of control means) of the valve operating system 100 of the second embodiment. The states of the components are shown collectively. It is assumed that the right end of Table 2 is continuous with the left end of Table 3 (excluding the item of mode).

[0035]

[Table 2]

[0036]

[Table 3]

The engine valve operating system 100 of the second embodiment is applied to an engine having at least two intake passages and intake ports per cylinder, and one intake valve is used when the engine is running at low speed or under low load. 0 lift and the other intake valve to L
If the control is performed so that the lift (or the H lift) is performed, the air-fuel mixture supply action works only in the intake passage 12 on one side, so that the air-fuel mixture can be swirled and supplied in the cylinder.

By the way, in common with the above-described first and second embodiments, the intake valve 40 and the auxiliary valve 60 can be engaged with each other via the hydraulic damper mechanism 300 as shown in FIG. That is, the stem 41 of the intake valve 40 has a small diameter portion 301
Thus, the shield wall 302 is formed above the stepped portion 48 of the stem 41 by a height β. In addition, an appropriate number of passages 304 are formed at a distance from the stepped portion 62 of the stem 63 of the auxiliary valve 60 and communicate with the inside and outside of the hole 303 for sliding the stem 41 formed in the stem 63.

This hydraulic damper mechanism 300 includes the intake valve 40.
The operation is performed from when the positional relationship shown in FIG. 15 is established between the auxiliary valve 60 and the auxiliary valve 60 until the positional relationship shown in FIG. 16 is obtained.

That is, the intake valve 40 is closed (upward in the drawing).
When the movement of the auxiliary valve 60 is not regulated when the auxiliary valve 60 moves, the stepped portion 48 of the stem 41 of the intake valve 40 is
By hitting the stepped portion 62 of the stem 63, the auxiliary valve 60 is also moved in the valve closing direction of the intake valve 40 (upward in the drawing). Immediately before the stepped portion 48 hits the stepped portion 62, that is, the upper end of the shield wall portion 302 as shown in the position of FIG.
When it coincides with the lower end of 3, the inside of the hole 305 for sliding the large diameter portion 47 of the stem 41 of the intake valve 40 formed in the stem 63,
A closed ring-shaped damper space 306 is formed around the shielding wall 302. When the intake valve 40 and the auxiliary valve 60 are in the positional relationship shown in FIG. 14, engine lubricating oil flows from the passage 304 to the damper space 306 through the outer circumference of the small diameter portion 301 of the stem 41 in the hole 303. Is being supplied. Therefore, the lubricating oil in the damper space 306 is compressed from the time when the intake valve 40 and the auxiliary valve 60 have the positional relationship shown in FIG. 15 to the positional relationship shown in FIG. From the small clearance for ensuring sliding, which is formed between the inner periphery of the hole 303 and the inner periphery of the hole 303, and leaks to the outer periphery of the small diameter portion 301, which causes a hydraulic damper action to generate the stem 41 of the intake valve 40.
The stepped portion 48 reduces the collision force of the stem 63 of the auxiliary valve 60 with the stepped portion 62.

Of course, this hydraulic damper mechanism 300 is
Even when the movement of the auxiliary valve 60 is restricted, it is always possible to act when the stepped portion 48 of the stem 41 of the intake valve 40 contacts the stepped portion 62 of the stem 63 of the auxiliary valve 60.

[0042]

As described above, in the engine valve operating system of the present invention, the auxiliary valve that makes the effective lift amount of the valve variable is engageable with the valve, and the movement amount of the auxiliary valve is restricted or controlled by the control means. It is not regulated and the engagement state between the valve and the auxiliary valve can be controlled. That is, if the movement amount of the auxiliary valve is completely regulated and brought into a stopped state, the effective lift amount of the valve becomes maximum, and if the movement amount of the auxiliary valve is not regulated, the effective lift amount of the valve becomes small.

Further, by engaging the valve and the auxiliary valve via the hydraulic damper mechanism, when the valve engages (abuts) on the auxiliary valve and a part thereof, the engaging engagement impact force is alleviated. Wear of each valve can be prevented.

[Brief description of drawings]

FIG. 1 is a sectional view of a valve operating system for an engine according to a first embodiment of the present invention.

FIG. 2 shows a view of the auxiliary valve in FIG.

FIG. 3 shows a hydraulic circuit diagram in FIG.

FIG. 4 shows an operation of H lift / L lift in FIG.

FIG. 5 is a characteristic diagram of an effective lift amount during L lift in FIGS. 1 and 6.

FIG. 6 is a characteristic diagram of an effective lift amount at the time of H lift in FIGS.

FIG. 7 is a sectional view of a valve operating system for an engine according to a second embodiment of the present invention.

8 shows a view of the auxiliary valve in FIG. 7 as seen from the direction of arrow B. FIG.

9 shows a hydraulic circuit diagram in FIG.

FIG. 10 shows the H lift operation in FIG. 7.

11 shows the L lift operation in FIG. 7. FIG.

FIG. 12 shows the zero lift operation in FIG. 7.

13 is a characteristic diagram of an effective lift amount when the lift is 0 in FIG.

FIG. 14 is a sectional view of a hydraulic damper mechanism used in the engine valve operating system of FIGS. 1 and 7.

FIG. 15 shows another state (1) in FIG.

FIG. 16 shows another state (2) in FIG.

FIG. 17 shows a block diagram of a prior art variable valve timing mechanism.

18 shows a top view of FIG. 17 when the high lift portion is effective.

FIG. 19 is a top view when the low lift portion in FIG. 17 is effective.

[Explanation of symbols]

 10 engine valve device, 21 cam, 40 intake valve (valve), 44 valve spring, 52 intake passage (intake and exhaust passage), 54 seat, 60 auxiliary valve, 300 hydraulic damper mechanism.

Claims (2)

[Claims] 1. A valve, a seat disposed at one end of an intake / exhaust passage, a valve spring for urging the valve in a direction for seating the valve on the seat, and a urging direction for moving the valve in and out of the seat. A valve operating device for an engine having a cam for controlling the movement state of the valve by a control means, and arranging an auxiliary valve for varying the effective lift amount of the valve so as to be engageable with the valve. Is in the first state, it regulates the movement amount of the auxiliary valve, and when the control means is in the second state, it does not regulate the movement amount of the auxiliary valve. . 2. The valve operating system for an engine according to claim 1, wherein the valve and the auxiliary valve are engaged with each other via a hydraulic damper mechanism.