Internal combustion engine

Description

[0001] The utility model relates to the field of engine building, namely to an internal combustion engine equipped with a system for regulating gas exchange in the cylinder.

[0002] Internal combustion engines equipped with systems for selectively turning on and off gas exchange in cylinders are widely known.

[0003] A valve lift device (EP 2941547 B1) is known, consisting of a valve, cam, cam follower, valve follower, hydraulic chamber, hydraulic accumulator, control valve, and rocker arm. The hydraulic chamber is located between the cam follower and valve follower and is connected to the hydraulic accumulator.

[0004] Also known is an internal combustion engine control system with deactivatable cylinders (RU 2133853 C1), comprising valve timing valves, hydraulic gas exchange shutoff mechanisms in the form of spring-loaded telescopic hydraulic cylinders, high-pressure fuel pumps with a drive containing a fuel shutoff mechanism, a working fluid pressure source, a control line, and a hydraulic distributor. The fuel shutoff mechanism is a pneumatic cylinder, and the hydraulic distributor is an electrohydraulic valve.

[0005] The disadvantages of known solutions include limited applicability due to the fuel delivery system, as when gas exchange in a cylinder is disabled, the control system automatically shuts off the fuel supply mechanism to that cylinder. The fuel supply shutoff mechanism is implemented using an in-line or individual injection pump for each cylinder, which, in turn, increases the engine's size and metal consumption. Another disadvantage is the need to create pressure in the control line of the gas exchange shutoff mechanism before starting the engine, as otherwise the engine will start with several cylinders disabled, reducing the system's service life and reliability.

[0006] A device for shutting off and regulating gas exchange in internal combustion engine cylinders (RU 2116482 C1) is also known. It comprises a pushrod, a cylindrical housing with a bottom housing a thrust piston interacting with a pushrod, and a control chamber communicating with a pressure source via a control system. The device is additionally equipped with a cylindrical stop, a spool valve, and a sensor unit. A throttling orifice is formed in the thrust piston body, connected via oil-draining grooves to an oil-draining channel.

[0007] A diesel engine with a variable intake valve control system and internal exhaust gas recirculation is known (EP 2184452 B1, prototype), comprising a camshaft with a cam, a valve connected to an engine cylinder, a pusher mechanism comprising a first piston, the rod of which is configured to interact with said cam, and a second piston, the rod of which is configured to interact with the valve, a working chamber located between said pistons, a hydraulic accumulator connected through a valve to the working chamber.

[0008] The disadvantages of these solutions include the need to create pressure in the control chamber of the gas exchange device before starting the engine; otherwise, the engine will start with gas exchange disabled in the deactivated cylinders. Another disadvantage is the need to constantly maintain pressure in the control chamber of the gas exchange device when gas exchange is enabled in the deactivated cylinders. This means the oil pump must constantly operate to maintain pressure and compensate for the oil released from the control chamber. Furthermore, the lack of pressure control in the working chamber leads to unstable system operation and incomplete valve opening.

[0009] The technical problem is to eliminate the shortcomings of the state of the art and develop an internal combustion engine with an improved system for regulating gas exchange in cylinders.

[0010] The technical result consists in increasing the service life of the internal combustion engine by increasing the reliability of the gas exchange control system in the cylinder of the internal combustion engine.

[0011] An internal combustion engine (ICE) comprises a cylinder block and a cylinder head; a cylinder located in the cylinder block; a crankcase connected to the cylinder block; an oil pump connected to the crankcase; a valve timing mechanism installed in the cylinder head and containing a valve and a camshaft with a cam connected to the engine cylinder, a valve rocker configured to interact with the valve, a lower pusher with a piston at the end configured to interact with the cam of the camshaft, and an upper pusher with a piston at the end configured to interact with the valve rocker, a hydraulic chamber located between the pistons of the lower pusher and the upper pusher, an actuator unit containing a hydraulic accumulator connected via a fluid medium through the first hydraulic distributor to the hydraulic chamber.The technical problem is solved and the technical result is achieved due to the fact that the actuator unit also contains a pressure sensor and a second hydraulic distributor, connected via a fluid medium to a hydraulic accumulator, wherein the second hydraulic distributor is designed with the possibility, when the pressure of the working fluid in the hydraulic accumulator drops below the first threshold pressure, of connecting via a fluid medium the hydraulic accumulator to an oil pump to increase the pressure in the hydraulic accumulator to a second threshold value, greater than the first threshold value.

[0012] The actuator block contains a check valve connected between the hydraulic chamber and the hydraulic accumulator, parallel to the first hydraulic distributor.

[0013] The actuator block contains a check valve connected between the second hydraulic distributor and the hydraulic accumulator.

[0014] Fig. 1 shows a diagram of the gas exchange control system in the cylinder of an internal combustion engine, with gas exchange in the cylinder turned on and the valve closed.

[0015] The following positions are indicated in the figure: 1 - valve; 2 - valve spring; 3 - valve rocker arm; 4 - upper tappet; 4a - upper tappet piston; 5 - lower tappet; 5a - lower tappet piston; 6 - return spring; 7 - hydraulic chamber; 8 - actuator block; 9 - camshaft; 10 - first hydraulic distributor; 11 - check valve; 12 - pressure sensor; 13 - hydraulic accumulator; 14 - second hydraulic distributor; 15 - check valve.

[0016] An internal combustion engine (ICE) comprises a cylinder block and a cylinder head. The cylinder block comprises at least one cylinder (not shown). The ICE also comprises a crankcase (not shown) connected to the cylinder block and containing oil for lubricating the ICE components, as well as an oil pump (not shown) connected to the crankcase, for example, mounted on the cylinder block crankcase. A valve timing mechanism is installed in the cylinder head, equipped with a variable valve timing system (hereinafter referred to as the variable valve timing system).

[0017] The gas distribution mechanism comprises a valve 1 connected to a cylinder, a valve spring 2, a valve rocker 3 configured to interact with said valve 1, an upper pusher 4 with a piston 4a at the end, a lower pusher 5 with a piston 5a at the end, a return spring 6 connected to the lower pusher 5, a hydraulic chamber 7, an actuator block 8 and a camshaft 9.

[0018] As shown in Fig. 1, the upper tappet 4 and the lower tappet 5 with their corresponding pistons 4a, 5a are located in a groove of the housing, in particular the cylinder block housing or the cylinder head housing of the internal combustion engine. The lower tappet 5 interacts with the cam of the camshaft 9 and is spring-loaded by a return spring 6. The upper tappet 4 interacts with the rocker arm 3 of the valve 1.

[0019] The upper pusher 4 and the lower pusher 5 are provided at the ends with pistons 4a and 5a, configured to move within the hydraulic chamber 7, the volume of which can vary depending on the distance between the pistons 4a, 5a. The hydraulic chamber 7 contains a working fluid - oil under pressure - so that the movement of the lower pusher 5 under the action of the camshaft cam 9 promotes the interaction of the pistons 5a and 4a through the working fluid in the hydraulic chamber 7 and leads to the movement of the piston 4a of the upper pusher 4 in the direction of the rocker arm 3 of the valve 1.

[0020] Hydraulic chamber 7 is connected via a fluid medium to an actuator block 8, which is connected to the engine, in particular, is installed in the cylinder head and contains a first hydraulic distributor 10, a check valve 11, a pressure sensor 12, a hydraulic accumulator 13, a second hydraulic distributor 14 and a check valve 15. To replenish the working fluid in the hydraulic accumulator 13, the second hydraulic distributor 14 is connected to the ICE lubrication system, i.e. it is connected via a fluid medium to the oil pump of the ICE lubrication system.

[0021] When the internal combustion engine is running on all cylinders, in particular with a load above a certain level, the first hydraulic distributor 10 closes the channel connecting the hydraulic chamber 7 and the hydraulic accumulator 13. The camshaft 9, rotating, acts on the lower tappet 5, which, in turn, through the hydraulic fluid acts on the upper tappet 4, as a result of which the upper tappet 4 rises, turning the rocker arm 3 and opening the valve 1. In the event of oil leaks from the hydraulic chamber 7, it is replenished with oil from the hydraulic accumulator 13 through the check valve 11, connected between the hydraulic chamber 7 and the hydraulic accumulator, parallel to the first hydraulic distributor 10.

[0022] Data received from pressure sensor 12 indicates the presence of hydraulic fluid in accumulator 13. If the accumulator's hydraulic fluid pressure drops below the first threshold, a signal is sent to second hydraulic distributor 14, which switches and connects the accumulator to the engine lubrication system oil pump, replenishing the accumulator's oil pressure to a second threshold, which is greater than the first threshold. Check valve 15, connected between second hydraulic distributor 14 and accumulator 13, prevents hydraulic fluid leakage through second hydraulic distributor 14.

[0023] When specified conditions are met, in particular, when the engine load drops below a certain level from the maximum power, the control system shuts off one or more engine cylinders. In this case, the first hydraulic distributor 10 switches and connects the hydraulic chamber 7 to the hydraulic accumulator 13. Thus, when the lower pusher 5 rises, the working fluid from chamber 7 is forced into the hydraulic accumulator 13; when the lower pusher 5 moves downward, the hydraulic chamber 7 is filled with working fluid from the hydraulic accumulator 13, while the upper pusher 4, rocker arm 3 and valve 1 remain stationary.

[0024] In particular, this cylinder gas exchange shutoff system can be used in the internal combustion engine of a diesel generator set (DGS). When the DGS is operating in its primary mode (primary power source), the engine load must be at least 50% of its maximum power. At lower loads, the internal combustion engine becomes unstable, causing the current frequency to fluctuate, and the engine itself to be subject to increased wear. Therefore, when the DGS drive load is less than 50% of its maximum power, one or more cylinders of the DGS are shut off. This means the intake and exhaust valves of the deactivated cylinders remain closed, and the fuel supply to these cylinders is cut off. The DGS operates more efficiently and reliably on the remaining cylinders, and the operating range of the DGS drive loads is 25-100% of its maximum power.

[0025] Thus, due to the presence of the first hydraulic distributor, pressure sensor and second hydraulic distributor in the actuator block of the gas exchange regulation system in the ICE cylinder, the service life of the ICE is increased by increasing the reliability, efficiency and stability of the gas exchange regulation system in the ICE cylinder.

Claims

1. An internal combustion engine (ICE) comprising a cylinder block and a cylinder head; a cylinder located in the cylinder block; a crankcase connected to the cylinder block; an oil pump connected to the crankcase; a valve timing mechanism installed in the cylinder head and comprising a valve and a camshaft with a cam connected to the engine cylinder, a valve rocker configured to interact with the valve, a lower tappet with a piston at the end configured to interact with the cam of the camshaft, and an upper tappet with a piston at the end configured to interact with the valve rocker, a hydraulic chamber located between the pistons of the lower tappet and the upper tappet, an actuator unit comprising a hydraulic accumulator connected through a fluid medium through a first hydraulic distributor to the hydraulic chamber, characterized in thatthat the actuator unit also contains a pressure sensor and a second hydraulic distributor, connected via a fluid medium to the hydraulic accumulator, wherein the second hydraulic distributor is configured to, when the pressure of the working fluid in the hydraulic accumulator drops below the first threshold pressure, connect via a fluid medium the hydraulic accumulator to the oil pump to increase the pressure in the hydraulic accumulator to a second threshold value greater than the first threshold value.

2. An internal combustion engine according to paragraph 1, characterized in that the actuator unit contains a check valve connected between the hydraulic chamber and the hydraulic accumulator, parallel to the first hydraulic distributor.

3. The internal combustion engine according to paragraph 1, characterized in that the actuator unit contains a check valve connected between the second hydraulic distributor and the hydraulic accumulator.

Images