JP2001329873A - Multi-cylinder internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To simplify a valve stopping mechanism, particularly to simplify and shorten a hydraulic fluid pressure supply passage thereof, in a multi-cylinder internal combustion engine realizing operation by a part of the cylinders. SOLUTION: A part of the cylinder bank is made to be multiple resting cylinders #3, #4 rested under a specified operating condition. An ignition order of the cylinder bank is made to be #1-#3-#2-#4 or #1-#4-#2-#3 so as to place the resting cylinder #3, #4 next to the engine on one side thereof with making an explosion stroke of remaining operating cylinders #1, #2 appear at specified phase intervals. The valve stopping mechanism for stopping intake and exhaust valves 10 of the resting cylinder according to hydraulic fluid pressure is provided to a valve lifter 24, a driving cam 26, and the like of the resting cylinder.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a multi-cylinder internal combustion engine for an automobile or the like which can perform a partial cylinder operation by stopping a part of cylinders in a cylinder row. The present invention relates to a multi-cylinder internal combustion engine provided with a valve stop mechanism for stopping an intake valve and / or an exhaust valve.

[0002]

2. Description of the Related Art Conventionally, a multi-cylinder internal combustion engine capable of performing a partial cylinder operation in which a part of cylinders of a cylinder row is stopped in order to improve exhaust performance and fuel efficiency during low load operation or the like has been known. Have been. Further, in order to reduce pumping loss and the like when performing such partial cylinder operation, there is also known a system provided with a valve stop mechanism for stopping an intake / exhaust valve of a deactivated cylinder.

[0003] As an example, Mitsubishi Motors New Guidebook No. 1 issued in January 1982. In the multi-cylinder internal combustion engine disclosed on pages 16 and 17 of No. 1030532, the ignition order is # 1.
The # 1 and # 4 cylinders in the # 3- # 4- # 2 cylinder row are deactivated cylinders. Further, a valve stopping mechanism suitable for a rocker arm type valve operating mechanism is disclosed.

On the other hand, FIG. 8 shows a valve stop mechanism disclosed in Japanese Patent Publication No. 8-508077 as a valve stop mechanism suitably applied to a direct-acting type valve train. In brief, the valve lifter of the deactivated cylinder is divided into a rod part 2 that moves up and down together with the intake / exhaust valve 1 and an outer cylinder part 3 that is pressed and driven by the driving cam 4. The rod portion 2 and the outer cylinder portion 3 can be directly connected to each other by a connecting pin 5. The connecting pin 5 is connected to an operating hydraulic pressure supplied through a hydraulic supply path such as an oil passage 7 formed in the cylinder block 6. Driven accordingly. When the rod portion 2 and the outer cylinder portion 3 are connected by the connecting pin 5, the intake / exhaust valve 1 is driven up and down by the drive cam 4, and when the two and 3 are not connected, the intake / exhaust valve 1 Is held in a stopped state.

[0005]

However, if the # 1 cylinder and the # 4 cylinder, which are deactivated cylinders, are arranged apart from each other as described in the above-mentioned manual, the structure of the valve stop mechanism becomes complicated. . For example, in a valve stop mechanism driven by hydraulic pressure as disclosed in JP-T-8-508077, the hydraulic supply path such as the oil passage 7 is complicated and long.

The present invention has been made in view of the above problems, and in a multi-cylinder internal combustion engine capable of realizing partial cylinder operation, simplification of a valve stop mechanism, particularly simplification and shortening of a hydraulic supply path thereof. It is an object of the present invention to provide a novel multi-cylinder internal combustion engine capable of realizing high performance.

[0007]

SUMMARY OF THE INVENTION A multi-cylinder internal combustion engine according to the present invention includes a plurality of deactivated cylinders that are deactivated in a predetermined operating state, and an active cylinder in which an explosion stroke appears at regular phase intervals.
And a valve stopping mechanism for stopping the intake and exhaust valves of the plurality of idle cylinders.

Accordingly, when the idle cylinder is stopped, the operating cylinder is ignited at a constant phase interval, and stable partial cylinder operation can be performed. In addition, when such a partial cylinder operation is performed, the intake and exhaust valves of the deactivated cylinders are stopped by the valve stop mechanism, so that a pumping loss can be reduced.

Further, the invention according to claim 1 is characterized in that the plurality of idle cylinders are arranged adjacent to one end of the engine.

That is, since the deactivated cylinders are arranged adjacent to one end of the engine so as to be concentrated and located adjacent to one end of the engine, the valve stop mechanism can also be arranged to be concentrated near one end of the engine. Can be simplified. In particular, in the case where the hydraulic pressure is supplied to the valve stop mechanism, the hydraulic pressure supply path can be significantly simplified and shortened.

In other words, if a plurality of inactive cylinders are intermittently arranged with the operating cylinder interposed therebetween, a valve stop mechanism is dispersedly arranged for each inactive cylinder, which complicates the configuration. In addition, when supplying operating hydraulic pressure to these valve stop mechanisms, the hydraulic pressure supply path becomes very complicated and long.

By the way, even when the deactivated cylinders are deactivated, the temperature of the cooling water flowing near these deactivated cylinders increases due to friction between the piston and the cylinder. Therefore, preferably, the plurality of idle cylinders are arranged downstream of the flow of cooling water flowing in the cylinder head. That is, the influence of the temperature rise of the cooling water due to the flow near the idle cylinder is prevented from being exerted on the operating cylinder that is actually operating.

According to a third aspect of the present invention, an oil passage for supplying an operating oil pressure to the valve stop mechanism is formed in the cylinder head.
The oil passage extends linearly in the cylinder row direction so as to communicate with the lifter bores of the plurality of idle cylinders.

In this case, the oil passage can be formed in a straight, simple and short configuration. In other words, if the idle cylinder is provided intermittently with the working cylinder interposed therebetween, the oil passage communicates with the lifter bore of the working cylinder, resulting in a decrease in hydraulic pressure.

According to a fourth aspect of the present invention, the valve stop mechanism includes a valve stop camshaft for driving the intake and exhaust valves of the plurality of idle cylinders, and shaft stop means for stopping the valve stop camshaft. It is characterized by having.

Thus, for example, when the present invention is applied to a DOHC type engine, a valve stopping camshaft is provided for each cylinder row.
When the present invention is applied to an SOHC type engine, only one cam shaft for valve stop needs to be provided for each cylinder row, so that the valve stop mechanism can be further simplified.

More specifically, as in the invention of claim 5,
The ignition order of the four cylinders constituting the above-mentioned cylinder row is # 1- #
The deactivated cylinders are # 1 and # 2 cylinders or # 3 and # 4 as 3- # 2- # 4 or # 1- # 4- # 2- # 3.
Cylinder.

Alternatively, as in the invention of claim 6, the ignition order of the six cylinders constituting the cylinder row is set to # 1- # 5- #
3- # 6- # 2- # 4, and the deactivated cylinders are # 1 and # 3
And # 2 cylinders, or # 5, # 6 and # 4 cylinders.

[0019]

As described above, according to the present invention, since a plurality of inactive cylinders are disposed adjacent to one end of the engine, the valve stop mechanism can be simplified, and in particular, the hydraulic supply path can be simplified and shortened. Can be.

[0020]

1 to 3 show an embodiment in which the present invention is applied to an in-line four-cylinder multi-cylinder internal combustion engine.
The # 1, # 2, # 3, and # 4 cylinders are arranged in series from the front of the engine on the left side in the figure.

This engine has two # 3 out of four cylinders in a row of cylinders in order to improve exhaust performance and fuel efficiency under predetermined operating conditions such as when the load is low.
The # 4 cylinder is a deactivated cylinder that is substantially deactivated, and a partial cylinder operation is performed in which only the remaining two # 1 and # 2 cylinders are operated. The above-mentioned deactivated cylinders # 3 and # 4 are disposed adjacent to one end of the engine, that is, adjacent to the rear end of the engine (or near the front end), and the operating cylinders # 1 and # 2 are positioned near the front end of the engine (or near the rear end). Is located next to

Further, during such partial cylinder operation, the explosion stroke of the working cylinder is set so as to appear at a constant phase interval. That is, in order to ignite the working cylinders at a substantially constant phase interval and arrange the idle cylinders adjacent to one end of the engine, the order of ignition in the cylinder row is conventionally set to # 1- # 3- # 4-. # 1- # 3- instead of # 2
# 2- # 4 or # 1- # 4- # 2- # 3. Further, with the change of the ignition order, the shape of the crankshaft, specifically, the position of the crankpin is changed so as to correspond to the shape.

Further, when such a partial cylinder operation is being performed, the supply of fuel to the deactivated cylinder is prohibited by the control of a control unit (not shown), and the deactivated cylinder is operated to reduce pumping loss. The operation of the intake and exhaust valves (intake and exhaust valves) 10 of the cylinder is stopped. That is, a valve stop mechanism for stopping the operation of the intake / exhaust valve 10 of the deactivated cylinder is provided.

Next, the mechanical structure of the internal combustion engine including such a valve stop mechanism will be described with reference to FIGS. Note that components common to the intake valve side and the exhaust valve side are denoted by the same reference numerals, and redundant description will be omitted as appropriate.

A pair of intake valves 10 and a pair of exhaust valves 10 ′ are provided for each cylinder on a cylinder head 14 mounted above the cylinder block 12. A side camshaft 16 and an exhaust side camshaft 16 are provided. The camshaft 16 is
Rotational power is transmitted from the crankshaft 18 via a pulley (or sprocket) 16a provided at the front end thereof and a belt (or chain) (not shown) provided at the front end thereof. Each intake / exhaust valve 10 is provided on the camshaft 16.
A drive cam 22 that presses and drives the valve lifter 20 of the working cylinder and a drive cam 26 that presses and drives the valve lifter 24 of the inactive cylinder are provided above.

The valve lifter 24 and the drive cam 26 for the deactivated cylinder constitute a main part of the valve stop mechanism.
The basic configuration of this valve stop mechanism is described in the above-mentioned Japanese Patent Application Laid-Open No. Hei 8-50.
It is well-known as disclosed in JP-A-8077.
Here, the valve lifter 24 will be briefly described with a detailed description omitted. As shown in FIG. 4, the valve lifter 24 includes a cylindrical outer cylindrical portion 30 movably fitted to a lifter bore 28 formed in the cylinder head 14. , And a rod portion 32 that moves up and down together with the intake / exhaust valve 10. On the other hand, the driving cam 26
Has a concave portion 26a formed at an axial center portion facing the rod portion 32 to avoid interference with the rod portion 32,
The cam surfaces 26b on both sides in the axial direction with the concave portion 26a interposed therebetween face the upper surface of the outer cylindrical portion 30, and press and drive the upper surface.

The outer cylinder portion 30 and the rod portion 32 have a structure which can be directly connected by a connecting pin (not shown). The connecting pin is connected to a hydraulic supply path (36, 3) shown in FIGS.
8, 40) according to the operating oil pressure supplied from the cylinder block 12 side. This hydraulic pressure supply path includes a first oil passage 36 and a second oil passage 38 formed in the cylinder head 14, a circumferential oil groove 40 recessed in the outer periphery of the outer cylindrical portion 32, and the like. The working oil pressure is
Switching is controlled by a solenoid valve 42 that opens and closes the second oil passage 38 according to the output signal of the control unit.

For example, normal operation other than partial cylinder operation,
That is, when all cylinders are operated, the outer cylinder portion 30 and the rod portion 32 are directly connected by the connecting pin. This allows
The pressing force of the cam surface 26b of the drive cam 26 pressing the upper surface of the outer cylinder portion 30 is transmitted to the intake / exhaust valve 10 of the idle cylinder, and the intake / exhaust valve 10 of the idle cylinder moves up and down similarly to the intake / exhaust valve of the active cylinder. I do. On the other hand, when performing the partial cylinder operation, the connection between the outer cylinder portion 30 and the rod portion 32 by the connecting pin is released.
As a result, the pressing force from the driving cam 26 is not transmitted to the rod portion 32 via the outer cylinder portion 30, and the intake and exhaust valve 10 remains stopped. That is, the valve is kept closed.

In this embodiment, since the deactivated cylinder is disposed adjacent to one end of the engine as described above, the above-described valve stop mechanism can also be disposed concentrated near one end of the engine. The structure of the valve stop mechanism can be simplified. In particular, it is possible to remarkably simplify and shorten the first oil passage 36 extending in the cylinder row direction in the cylinder head 14, more specifically, the hydraulic supply path for supplying the operating oil pressure to the valve stop mechanism. That is, the first oil passage 36 can be formed in a simple shape extending linearly along the cylinder row direction such that a part thereof communicates with the lifter bores 28 of the deactivated cylinders # 3 and # 4. Therefore, for example, after the cylinder head 14 is formed, the first oil passage 36 (and the second oil passage 38) can be easily formed later. In this case, it is necessary to close the opening of the first oil passage 36 with an end cap (not shown).

In other words, if the idle cylinders are intermittently arranged with the working cylinder interposed therebetween, the first oil passage is inevitably elongated and communicates with the lifter bore of the working cylinder. There is a possibility that hydraulic oil leaks into the lifter bore of the working cylinder and the hydraulic pressure drops. If the # 1 and # 4 cylinders on both sides are assumed to be idle cylinders, it is necessary to provide the oil passages 36 and 38 as described above both before and after the engine. Invite you to

FIG. 5 schematically shows the flow of the cooling water of the engine, wherein 44 is a radiator, 46 is a water pump, and 48 is a thermostat. As shown by the arrow A in the figure, the cylinder head 14 (and the cylinder block 1)
In 2), the cooling water is set to flow from the front to the rear of the engine in the water jacket, and the deactivated cylinders # 3 and # 4 are provided downstream of the cooling water flow A of the cylinder head 14 as described above. They are located next to each other.

FIG. 6 is a graph showing the temperature change of the cooling water flowing near each cylinder during the partial cylinder operation in which the deactivated cylinder is deactivated. As shown in the figure, the cooling water not only passes through the vicinity of the operating cylinders # 1 and # 2, but also
Also when passing near the deactivated cylinders # 3 and # 4, the temperature is increased by friction or the like. Therefore, if the idle cylinder is disposed upstream of the flow of the cooling water, the temperature of the cooling water passing through the vicinity of the active cylinder increases because the temperature of the cooling water rises while passing near the idle cylinder. I will. On the other hand, by disposing the idle cylinder downstream of the cooling water flow as in the present embodiment, the radiator 44
Since the cooling water cooled by the cooling air flows near the working cylinder without being heated by friction of the idle cylinder, the temperature of the cooling water flowing near the working cylinder can be effectively suppressed, and abnormal combustion such as knocking can be suppressed. Occurrence and the like can be more reliably prevented.

FIG. 7 shows another example of a valve stop mechanism applicable to the internal combustion engine shown in FIGS. This valve stop mechanism is a main camshaft 5 that drives intake and exhaust valves of the working cylinder.
In addition to 0 (16), a valve stop camshaft 52 for driving the intake / exhaust valve of the deactivated cylinder is provided. This cam shaft 52 for stopping the valve is provided with the deactivated cylinders # 3 and # 3.
A plurality of drive cams 54 for pressing and driving the # 4 intake / exhaust valve are provided on the outer periphery, and are fitted around the outer periphery of the main camshaft 50 via bearings 56 so as to be relatively rotatable. It is rotatably supported on the cylinder head side. And the main camshaft 50
Is provided with a connecting pin 60 which is inserted into the concave portion 52a of the valve stopping camshaft 52 according to the supplied oil pressure (shaft stopping means).

At the time of partial cylinder operation, a predetermined hydraulic pressure is supplied through a hydraulic passage 62 in the main camshaft 50, so that the connecting pin 60 is separated from the main camshaft 50 against the spring force of the return spring 64. The connecting pin 60 moves in a direction away from the right side (rightward in FIG. 7), and is brought into a state in which the connecting pin 60 is pulled out from the concave portion 52a of the valve stopping cam shaft 52.
Therefore, the rotational power is not transmitted from the main camshaft 50 to the valve stop camshaft 52, and the intake and exhaust valves of the deactivated cylinders are held (stopped) in the closed state.

On the other hand, in a normal operation state other than the partial cylinder operation, by reducing the hydraulic pressure supplied to the connecting pin 60, the connecting pin 60 is moved into the concave portion 52 a of the valve stopping cam shaft 52 by the spring force of the return spring 64. The camshafts 50 and 52 are directly connected. Thus, the main camshaft 50 is moved from the camshaft 52 for stopping the valve.
The rotational power is transmitted to the idle cylinder, and the intake / exhaust valves of the idle cylinders also move up and down similarly to the intake / exhaust valves of the active cylinders.

Here, if the deactivated cylinders are spaced apart like # 1 and # 4 cylinders, it is necessary to provide the above-described valve stop camshafts 52 at the front and rear ends of the engine, respectively. The configuration becomes complicated. On the other hand, when the deactivated cylinders are arranged adjacent to one end of the engine as shown in FIG. 7, the suction of all the deactivated cylinders # 3 and # 4 in the cylinder row by one valve stop camshaft 52. The exhaust valve can be driven, and the configuration can be simplified. For example, FIG.
In the DOHC type internal combustion engine as shown in FIG. 3, only two valve stop camshafts 52 need to be provided for each cylinder row, and in the SOHC type engine, only one camshaft 52 is required.

The present invention is not limited to the above-described embodiment, and various modifications and changes can be made without departing from the gist of the present invention. For example, in an in-line six-cylinder internal combustion engine, the ignition order is set to # 1- # 5- # 3- # 6- # 2-
In this case, the idle cylinders may be # 1, # 3 and # 2 cylinders, or # 5, # 6 and # 4 cylinders.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a multi-cylinder internal combustion engine according to an embodiment of the present invention.

FIG. 2 is a top view corresponding to the internal combustion engine of FIG. 1;

FIG. 3 is a configuration diagram schematically showing a valve stop mechanism and a hydraulic supply path thereof according to the embodiment.

FIG. 4 is a sectional view showing a main part of the valve stop mechanism.

FIG. 5 is a configuration diagram schematically showing a flow of cooling water of the internal combustion engine of FIG. 1;

FIG. 6 is a graph showing a temperature change of cooling water flowing near each cylinder.

FIG. 7 is a configuration diagram showing another example of the valve stop mechanism.

FIG. 8 is a sectional view showing a conventional valve stop mechanism.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 ... Intake / exhaust valve 14 ... Cylinder head 24 ... Valve lifter (valve stop mechanism) 26 ... Drive cam (valve stop mechanism) 36 ... 1st oil passage 52 ... Valve stop camshaft 60 ... Connection pin (shaft stop means) # 1 , # 2 ... working cylinder # 3 ... # 4 ... idle cylinder

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F02F 1/00 F02F 1/00 N 1/24 1/24 G K 1/38 1/38 B 1/40 1/40 CF term (reference) 3G018 AA05 AB07 AB17 AB18 BA02 BA09 BA22 BA29 BA36 CA09 CA19 DA03 DA05 DA17 DA18 DA24 DA30 DA52 DA58 DA69 DA83 FA12 FA26 GA14 3G024 AA05 AA17 AA21 BA23 CA05 DA05 DA10 DA18 3G092 AA01 AA01 AB04 CB02 DA01 DA02 EA14 FA24 GA05

Claims (6)

[Claims] 1. A cylinder row is composed of a plurality of deactivated cylinders that are deactivated in a predetermined operation state and an active cylinder in which an explosion stroke appears at a predetermined phase interval, and the intake and exhaust of the deactivated cylinders is performed. A multi-cylinder internal combustion engine having a valve stop mechanism for stopping a valve, wherein the plurality of inactive cylinders are disposed adjacent to one end of the engine. 2. The multi-cylinder internal combustion engine according to claim 1, wherein the plurality of idle cylinders are arranged downstream of a flow of cooling water flowing in a cylinder head. 3. An oil passage for supplying an operating oil pressure to the valve stop mechanism is formed in the cylinder head, and the oil passage is linearly arranged in the cylinder row direction so as to communicate with the lifter bores of the plurality of idle cylinders. 3. The multi-cylinder internal combustion engine according to claim 1, wherein the engine extends. 4. A valve stopping camshaft for driving intake and exhaust valves of the plurality of idle cylinders, a shaft stopping means for stopping the valve stopping camshaft,
The multi-cylinder internal combustion engine according to claim 1 or 2, comprising: 5. The ignition sequence of the four cylinders constituting the above-mentioned cylinder row is set to # 1- # 3- # 2- # 4 or # 1- # 4- # 2-
5. The cylinder as # 3, wherein the deactivated cylinders are # 1 and # 2 cylinders or # 3 and # 4 cylinders.
A multi-cylinder internal combustion engine according to any one of the above. 6. An ignition sequence of six cylinders constituting the cylinder row is # 1- # 5- # 3- # 6- # 2- # 4, and the idle cylinders are # 1, # 3 and # 2 cylinders. Or # 5, #
The multi-cylinder internal combustion engine according to any one of claims 1 to 4, wherein the engine is a six-cylinder and a # 4 cylinder.