Patent Application
20160160701
The present application claims priority of Korean Patent Application Number 10-2014-0175830 filed on Dec. 9, 2014, the entire contents of which application are incorporated herein for all purposes by this reference.
1. Field of Invention
The present invention relates to a cylinder deactivation engine. More particularly, the present invention relates to a cylinder deactivation engine that can change the valve lifts of cylinders that are not deactivated.
2. Description of Related Art
In general, an internal combustion engine is an apparatus that operates using energy from heat generated by burning a gas mixture in a combustion chamber. A multi-cylinder engine with a plurality of cylinders for increasing power and reducing noise and vibration is generally used.
Recently, a cylinder deactivation apparatus of an engine that improves fuel efficiency by deactivating some of a plurality of cylinders in an engine when the engine generates small power has been developed as a result of an increase in energy cost.
One way of deactivating cylinders used by such a cylinder deactivation apparatus is to operate an engine by injecting and burning a gas mixture in only some of a plurality of cylinders without injecting and igniting a gas mixture in the other cylinders. For example, for a four-cylinder engine, the apparatus does not inject and ignite a gas mixture in two cylinders but operates the engine with only the other two cylinders.
Meanwhile, a variable valve lift technique that selectively implements a zero lift of a valve so that a gas mixture is not injected may be applied to deactivated cylinders.
However, in a cylinder deactivation engine implemented by the existing cylinder deactivation apparatuses, valves of cylinders that are not deactivated operate to normal lifts, so appropriate valve lifts according to the speed of an engine cannot be achieved. Further, when the configuration for changing the valve lifts of cylinders that are not deactivated is complicated, the weight and manufacturing cost of an engine may be excessively increased.
The information disclosed in this Background section is only for enhancement of understanding of the general background of the invention and should not be taken as an acknowledgement or any form of suggestion that this information forms the prior art already known to a person skilled in the art.
The present invention has been made in an effort to provide a cylinder deactivation engine that deactivates some of cylinders and changes valve lifts of the other cylinders.
In various aspects, the present invention provides a cylinder deactivation engine that includes two or more cylinders and selectively deactivates some of the cylinders. The cylinder deactivation engine may include: one or more deactivation cylinders to be selectively deactivated; one or more non-deactivation cylinders not to be deactivated; cylinder deactivation apparatuses operably connected to the one or more deactivation cylinders and operated by hydraulic pressure to selectively implement a zero lift of a valve or valves of the one or more deactivation cylinders; one or more variable valve lift apparatuses operably connected to the one or more non-deactivation cylinders and operated by the hydraulic pressure to selectively change a lift of a valve of the one or more non-deactivation cylinders; a hydraulic pump that generates the hydraulic pressure for operating the one or more variable valve lift apparatuses and the cylinder deactivation apparatuses; and one or more oil control valves that control the hydraulic pressure from the oil pump so that the hydraulic pressure is selectively supplied to the one or more variable valve lift apparatuses and the cylinder deactivation apparatuses
Each cylinder deactivation apparatus may be disposed at an intake part to operate an intake valve of a corresponding deactivation cylinder or at an exhaust part to operate an exhaust valve of the corresponding deactivation cylinder. Each variable valve lift apparatus may be disposed at the intake part to operate the intake valve of a corresponding non-deactivation cylinder.
The oil control valve may communicate with two cylinder deactivation apparatuses provided for each of the one or more deactivation cylinders and with one variable valve lift apparatus provided for each of the one or more non-deactivation cylinders.
The variable valve lift apparatus may include: an outer body that selectively pivots with rotation of a cam, has a first end connected with the intake valve of the corresponding non-deactivation cylinder and a second end mounted with a pivot shaft, and has an internal space; an inner body that is disposed in the internal space of the outer body and has a first end rotatably connected with the first end of the outer body; a connecting shaft that is disposed through the first end of the outer body and the first end of the outer body and connects the outer body and the inner body to each other; and a lost motion spring that returns the inner body that has rotated about the connecting shaft relative to the outer body.
When the hydraulic pressure is supplied to the variable valve lift apparatus, the inner body may be fixed to the outer body; when the cam rotates, the inner body may pivot with the outer body on a pivot shaft of the outer body; when the hydraulic pressure supplied to the variable valve lift apparatus is removed, the inner body may be unfixed from the outer body; and when the cam rotates, the inner body may pivot on the connecting shaft.
The variable valve lift apparatus may further include a latching pin and a latching spring disposed in the outer body. When the hydraulic pressure is supplied to the variable valve lift apparatus, the inner body may be fixed to the outer body by the latching pin; and when the hydraulic pressure supplied to the variable valve lift apparatus is removed, the latching pin may be returned by the latching spring, and the inner body and the outer body are unfixed.
When the outer body pivots with the inner body, a high lift of the intake valve may be implemented; and when the outer body pivots while being locked by the inner body that has pivoted on the connecting shaft, a normal lift of the intake valve may be implemented.
The inner body may be formed with an internal space of the inner body; and the variable valve lift apparatus may further include a roller that is disposed in the internal space of the inner body, is rotatably connected to the inner body, and is in rolling contact with the cam so that the inner body pivots with the rotation of the cam.
The cylinder deactivation apparatus may include: an outer body that selectively pivots with rotation of a cam, has a first end connected with the intake or exhaust valve of the corresponding deactivation cylinder and a second end mounted with a pivot shaft, and has an internal space; an inner body that is disposed in the internal space of the outer body and has a first end rotatably connected with the first end of the outer body; a connecting shaft that is disposed through the first end of the outer body and the first end of the outer body and connects the outer body and the inner body to each other; and a lost motion spring that returns the inner body that has rotated about the connecting shaft relative to the outer body.
When the hydraulic pressure supplied to the cylinder deactivation apparatus is removed, the inner body may be fixed to the outer body; when the cam rotates, the inner body may pivot with the outer body on a pivot shaft of the outer body; when the hydraulic pressure is supplied to the cylinder deactivation apparatus, the inner body may be unfixed from the outer body and only the inner body may pivot on the connecting shaft with the rotation of the cam.
The cylinder deactivation apparatus may further include a latching pin and a latching spring disposed in the outer body. When the hydraulic pressure supplied to the cylinder deactivation apparatus is removed, the latching pin pushed in a first direction by the latching spring may fix the outer body to the inner body; and when the hydraulic pressure is supplied to the cylinder deactivation apparatus, the latching pin may be pushed in a second direction, and the inner body and the outer body may be unfixed.
When the outer body pivots with the inner body, a normal lift of the valve may be implemented; and when only the inner body pivots on the connecting shaft, a zero lift of the valve may be implemented.
The inner body may be formed with an internal space; and the cylinder deactivation apparatus may further include a roller that is disposed in the internal space of the inner body, is rotatably connected to the inner body, and is in rolling contact with the cam so that the inner body pivots with the rotation of the cam.
The methods and apparatuses of the present invention have other features and advantages which will be apparent from or are set forth in more detail in the accompanying drawings, which are incorporated herein, and the following Detailed Description, which together serve to explain certain principles of the present invention.
Reference will now be made in detail to various embodiments of the present invention(s), examples of which are illustrated in the accompanying drawings and described below. While the invention(s) will be described in conjunction with exemplary embodiments, it will be understood that present description is not intended to limit the invention(s) to those exemplary embodiments. On the contrary, the invention(s) is/are intended to cover not only the exemplary embodiments, but also various alternatives, modifications, equivalents and other embodiments, which may be included within the spirit and scope of the invention as defined by the appended claims.
The outer body 110 pivots by selectively receiving torque of a camshaft to open/close a valve. A cam 5 (see, for example,
The valve is connected to a first end of the outer body 110 and a pivot shaft is disposed at a second end of the outer body 110. The internal space 112 of the outer body 110 is open at the first end, so the outer body 110 can generally have a U-shape.
In the following description, first ends and second ends of the components disposed on or coupled to the outer body 110 mean portions in the same directions as the first end and the second end of the outer body 110.
The inner body 120 is disposed in the internal space 112 of the outer body 110. A first end of the inner body 120 is rotatably coupled to the first end of the outer body 110. Further, the inner body 120 pivots by receiving torque of the camshaft to open/close a valve. A space is formed through the inner body 120, perpendicular to the inner body 20. That is, the inner body 120 has a predetermined length to pivot and has predetermined width and thickness such that the internal space 124 of the inner body 120 is defined.
The roller 130 is disposed in the internal space 124 of the inner body 120. The roller 130 is rotatably coupled to the inner body 120. A roller rotation shaft 135 is provided to rotatably connect the roller 130 and the inner body 120. That is, the roller 130 rotates about the roller rotation shaft 135. The roller 130 is in rolling contact with the cam 5 to convert the rotation of the camshaft into the pivot of the outer body 110 or the inner body 120.
The connecting shaft 140 connects the first end of the outer body 110 with the first end of the inner body 120 such that they can rotate. That is, the inner body 120 can rotate about the connecting shaft 140 relative to the outer body 110. The first end of the outer body 110 connected with the inner body 20 by the connecting shaft 140 is referred to as an outer connecting portion 114, and the first end of the inner body 120 connected with the outer body 110 by the connecting shaft 140 is referred to as an inner connecting portion 122.
A valve contact portion 116 is formed or disposed close to the outer connecting portion 114 at the first end of the outer body 110. In some embodiments, two outer connecting portions 114 may be formed at the first end of the outer body 110 that are open to a side. Accordingly, two valve contact portions 116 may be formed or disposed close to the two outer connecting portions 114, respectively. Further, the valve contact portions 116 push two valves, respectively, with pivot of the outer body 110 in contact with the valves.
The inner body 120 may be selectively fixed to the outer body 110 and may pivot with it, or may be selectively unfixed from the outer body 110 and may independently pivot. The lost motion spring 150 returns the inner body 120 that has rotated relative to the outer body 110 by independently pivoting, when the inner body 120 is unfixed from the outer body 110
The latching pin hole 129 is formed so that a fixing member, which selectively fixes the inner body 120 to the outer body 110, such as the latching pin 160, is inserted therein. Although the latching pin 160 is shown as the fixing member in
The stopper 167 is provided to prevent the latching pin 160 from separating out of the second end of the outer body 110. A hydraulic chamber 169 is defined between the stopper 167 and the latching pin 160 by the outer body 110, the stopper 167, and the latching pin 160. Further, the latching pin 160 is pushed toward the first end of the outer body 110 and inserted into the latching pin hole 129 by hydraulic pressure supplied to the hydraulic chamber 169, so the inner body 120 is fixed to the outer body 110.
The latching spring 165 is provided to return the latching pin 160 to the position before it is pushed by the hydraulic pressure. That is, when the hydraulic pressure supplied to the hydraulic chamber 169 is removed, the latching pin 160 is returned by the latching spring 165, and the inner body 120 and the outer body 110 are unfixed.
When the inner body 120 is fixed to the outer body 110, the inner body 120 and the outer body 110 pivot together on the pivot shaft of the outer body 110 by rotation of the cam 5 being in rolling contact with the roller 130. Further, when the inner body 120 is unfixed from the outer body 110, the inner body 120 pivots on the connecting shaft 140 by rotation of the cam 5 being in contact with the roller 130 and the outer body 110 is locked by the inner body 120, which has pivoted on the connecting shaft 140, and pivots on the pivot shaft of the outer body 110.
A high lift of the valve can be made by the outer body 110 pivoting with the inner body 120 and a normal lift of the valve can be made by the outer body 110 that pivots while being locked by the inner body 120 that has pivoted on the connecting shaft 40.
The outer body 210 pivots by selectively receiving torque of a camshaft to open/close a valve. A cam 5 is formed or disposed on the camshaft to convert the rotation of the camshaft into the pivot of the outer body 210. The valve is an intake valve or an exhaust valve. A space 212 is formed through the outer body 210 perpendicular to the outer body 210. That is, the outer body 210 has a predetermined length to pivot and has predetermined width and thickness such that the internal space 212 of the outer body 210 is defined.
The valve is connected to a first end of the outer body 210 and a pivot shaft is disposed at a second end of the outer body 210. The internal space 212 of the outer body 210 is open at the first end, so the outer body 210 can generally have a U-shape.
In the following description, first ends and second ends of the components disposed on or coupled to the outer body 210 mean portions in the same directions as the first end and the second end of the outer body 210.
The inner body 220 is disposed in the internal space 112 of the outer body 210. A first end of the inner body 220 is rotatably coupled to the first end of the outer body 210. Further, the inner body 220 pivots by receiving torque of the camshaft to selectively open/close a valve. A space is formed through the inner body 220, perpendicular to the inner body 220. That is, the inner body 220 has a predetermined length to pivot and has predetermined width and thickness such that an internal space 224 of the inner body 220 is defined.
The roller 230 is disposed in the internal space 224 of the inner body 220. The roller 230 is rotatably coupled to the inner body 220. A roller rotation shaft 235 is provided to rotatably connect the roller 230 and the inner body 220. That is, the roller 230 rotates about the roller rotation shaft 235. The roller 230 is in rolling contact with the cam 5 to convert the rotation of the camshaft into the pivot of the outer body 210 or the inner body 220.
The connecting shaft 240 connects the first end of the outer body 210 with the first end of the inner body 220 such that they can rotate. That is, the inner body 220 can rotate about the connecting shaft 240 relative to the outer body 210. The first end of the outer body 210 connected with the inner body 220 by the connecting shaft 240 is referred to as an outer connecting portion 214, and the first end of the inner body 220 connected with the outer body 210 by the connecting shaft 240 is referred to as an inner connecting portion 222.
A valve contact portion 216 is formed or disposed close to the outer connecting portion 214 at the first end of the outer body 210. Two outer connecting portions 214 may be formed at the first end of the outer body 210 that are open to a side. Accordingly, two valve contact portions 216 may be formed or disposed close to the two outer connecting portions 214, respectively. Further, the valve contact portions 216 push two valves, respectively, with pivot of the outer body 210 in contact with the valves.
The inner body 220 may be selectively fixed to the outer body 210 and may pivot with it, or may be selectively unfixed from the outer body 110 and may independently pivot.
The lost motion spring 250 returns the inner body 220 that has rotated relative to the outer body 210 by independently pivoting, when the inner body 220 is unfixed from the outer body 210
The latching pin holes 229 are formed to receive the latching pin 260. The latching pin 260 is operated by hydraulic pressure, and may be disposed at the second end of the outer body 210 to be easily supplied with hydraulic pressure. A component for supplying hydraulic pressure such as an HLA (Hydraulic Lash Adjuster) may be disposed at the second end of the outer body 210.
The stopper 267 is provided to prevent the latching pin 260 from separating out of the second end of the outer body 210.
As the latching pin 260 is inserted in the latching pin hole 229 by an elastic force of the latching spring 265, the inner body 220 can be fixed to the outer body 210. That is, the latching spring 265 is disposed between the stopper 267 and the latching pin 260 to push the latching pin 260 toward the inner body 220 with its first end. A hydraulic chamber 269 is defined at a first end of the latching pin 260 by the outer body 210 and the latching pin 260. As the latching pin 260 is pushed toward the second end of the outer body 210 by the hydraulic pressure supplied to the hydraulic chamber 269, the inner body 220 and the outer body 210 are unfixed. In other words, when the hydraulic pressure supplied to the hydraulic chamber 269 is removed, the latching pin 260 is returned into the latching pin hole 229 by the latching spring 265, such that the inner body 220 is fixed to the outer body 210.
When the inner body 220 is fixed to the outer body 210, the inner body 220 and the outer body 210 pivot together on the pivot shaft of the outer body 210 by rotation of the cam 5 being in rolling contact with the roller 230. When the inner body 220 is separated from the outer body 210, only the inner body 220 pivots on the connecting shaft 240 by rotation of the cam 5 being in rolling contact with the roller 230.
A normal lift of the valve can be made by the outer body 210 pivoting with the inner body 220, and a zero lift of the valve can be made by the outer body 110 that does not pivot when only the inner body 220 pivots. That is, a cylinder can be deactivated.
By way of illustration, the cylinders that are selectively deactivated are referred to as deactivation cylinders Cyl 2 and Cyl 3, while the cylinders that are not deactivated are referred to as non-deactivation cylinders Cyl 1 and Cyl 4. In
As shown in
The variable valve lift apparatus 100 is disposed to open/close the intake valves of the non-deactivation cylinders Cyl 1 and Cyl 4 by pivoting. Further, the variable valve lift apparatus 100 operates to selectively implement a normal lift or a high lift of the intake valves of the non-deactivation cylinders Cyl 1 and Cyl 4.
The cylinder deactivation apparatus 200 is disposed to open/close the exhaust valves and the intake valves of the deactivation cylinders Cyl 2 and Cyl 3 by pivoting. Two cylinder deactivation apparatuses 200 are provided for each of the deactivation cylinders Cyl 2 and Cyl 3 to open/close the exhaust valve and the intake valve. That is, the cylinder deactivation mechanism 200 is provided to selectively implement a normal lift or a zero lift of the exhaust valves and the intake valves of the deactivation cylinders Cyl 2 and Cyl 3.
The valve opening/closing unit 300 is disposed to open/close the exhaust valves of the non-deactivation cylinders Cyl 1 and Cyl 4. The valve opening/closing unit 300 implements a predetermined signal lift of the exhaust valves of the non-deactivation cylinders Cyl 1 and Cyl 4.
The oil pump 400 pumps oil to generate hydraulic pressure for operating the variable valve lift apparatus 100 and the cylinder deactivation apparatus 200. The oil pump 400 is the same as or similar to those in the art, so the detailed description is not provided.
The oil control valve 500 controls the hydraulic pressure from the oil pump 400 so that the hydraulic pressure is selectively supplied to the variable valve lift apparatus 100 and the cylinder deactivation apparatus 200. The basic configuration and function of the oil control valve 500 are the same as or similar to those in the art, so the detailed description is not provided.
Multi-cylinder engines are equipped with one or more oil control valves 500, and the oil control valve 500 communicates with the one variable valve lift apparatus 100 for each of the non-deactivation cylinders Cyl 1 and Cyl 4 and with two cylinder deactivation apparatuses 200 for each of the deactivation cylinders Cyl 2 and Cyl 3. That is, the oil control valve 500 selectively supplies oil to one variable valve lift apparatus 100 and two cylinder deactivation apparatus 200.
By way of illustration, in
As described above, according to an exemplary embodiment of the present invention, it is possible to implement variable valve lifts of the non-deactivation cylinders Cyl 1 and Cyl 4 while deactivating the deactivation cylinders Cyl 2 and Cyl 3. Therefore, it is possible to maximize improvement of fuel efficiency. Further, one oil control valve 500 controls deactivation of one of the deactivation cylinders Cyl 2 and Cyl 3 and the variable valve lift of one of the non-deactivation cylinders Cyl 1 and Cyl 4, such that it is possible to prevent unnecessary increase of the weight and manufacturing cost of an engine.
For convenience in explanation and accurate definition in the appended claims, the terms “inner” or “outer”, and etc. are used to describe features of the exemplary embodiments with reference to the positions of such features as displayed in the figures.
The foregoing descriptions of specific exemplary embodiments of the present invention have been presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed, and obviously many modifications and variations are possible in light of the above teachings. The exemplary embodiments were chosen and described in order to explain certain principles of the invention and their practical application, to thereby enable others skilled in the art to make and utilize various exemplary embodiments of the present invention, as well as various alternatives and modifications thereof. It is intended that the scope of the invention be defined by the Claims appended hereto and their equivalents.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2014-0175830 | Dec 2014 | KR | national |
