JP6066664B2 - Internal combustion engine - Google Patents

Description

  The present invention relates to an internal combustion engine equipped with an exhaust turbocharger.

  In recent years, an internal combustion engine is often provided with an exhaust turbocharger in order to obtain a high output. However, the exhaust turbocharger is driven as necessary, and the turbine of the exhaust turbocharger is provided there. In order to control the amount of exhaust gas flowing through the exhaust gas passage, a bypass passage is provided in front of the turbine in the exhaust gas passage, and the amount of exhaust gas flowing through the bypass passage is controlled by a wastegate valve.

State and opening and closing operation of the waste gate valve is the type which is automatically controlled in conjunction with the intake pressure and the like, but there is the case that is controlled by the remote controlled actuator such as an electric motor, for example, waste gate valve is closed In the case where the actuator fails, there is a possibility that the means for releasing the exhaust gas is lost and the pressure of the exhaust pipe rises abnormally, or the turbine overrotates and hinders intake control.

  As a measure in the case of an actuator failure as described above, Patent Document 1 describes that a safety valve is provided in the intake system, and when the intake system becomes excessive pressure, the safety valve is opened to lower the pressure in the intake system. Has been.

Japanese Utility Model Sho 62-76252 microfilm

  Although Patent Document 1 can prevent the intake system from being supercharged, there is a problem that the cost increases because a safety valve must be provided. Further, since the exhaust gas is not allowed to escape, the phenomenon that the pressure in the exhaust passage rises abnormally cannot be prevented, and it can be said that this is not a radical solution.

  The present invention has been made in view of the present situation, and an object of the present invention is to provide an apparatus capable of suppressing an increase in cost while being excellent in function as a safety device.

The present invention is
A wastegate valve for controlling the amount of exhaust gas flowing toward the turbocharger turbine; and an actuator for opening and closing the wastegate valve; and the movement of a rod provided on the actuator is a power transmission It is a configuration that is transmitted to the wastegate valve through a section,
State during the preceding power transmission unit, the elastic body is a rod predetermined force to the waste gate valve in a state that does not move is deformed et bullet resistance acts allow dynamic opening of the wastegate valve, said rod moves Then, it is provided so as to transmit the movement of the rod to the wastegate valve without elastic deformation.

For example, a spring body such as a coil spring, a leaf spring, or a torsion bar can be used as the elastic body . How to deform the elastic body may be set according to the aspect of the wastegate valve or the actuator.

In the present invention, even if the actuator malfunctions with the wastegate valve closed, if the upstream side of the turbine reaches a preset dangerous pressure, the elastic body is elastically deformed to open the wastegate valve, and the exhaust gas passes through the bypass passage. To the downstream side. For this reason, it is possible to prevent the exhaust passage from becoming an abnormally high pressure and maintain the safe operation of the internal combustion engine. In other words, since the exhaust gas is forcibly released, the function as a safety device is excellent. Moreover, because interlocking member is that acts as a safety device, the structure can be prevented easily and cost.

BRIEF DESCRIPTION OF THE DRAWINGS It is a figure which shows embodiment, (A) is a plane sectional view, (B) is the top view which displayed the drive mechanism, (C) is the fragmentary figure which shows an effect | action.

  Next, an embodiment of the present invention will be described with reference to the drawings. The exhaust turbocharger 1 is inserted in an exhaust gas passage (exhaust pipe) 2 and includes a housing 3 fixed to the exhaust gas passage 2. Inside the housing 3, an exhaust gas passage 6 is vacant with the inlet 4 and the outlet 5 being orthogonal to each other, and a turbine 7 driven by the exhaust gas is rotatably held. The exhaust gas hits the turbine 7 from the outside in the radial direction and escapes in the axial direction. Needless to say, the turbine 7 is fixed to one end portion of the rotating shaft 8, and the compressor blade is fixed to the other end portion of the rotating shaft 8.

  In the housing 3, a bypass passage 9 is formed in which exhaust gas is leaked to the outlet 5 without being guided to the turbine 7, and a wastegate valve 10 is provided at the entrance of the bypass passage 9. The wastegate valve 10 is connected to the housing 3 by a support shaft 11 so as to rotate about one end thereof. Note that the wastegate valve 10 may be a butterfly valve type, and in this case, the support shaft 11 is fixed to the central portion of the wastegate valve 10.

  The support shaft 11 protrudes above the housing 3, and one end portion of the lever member 12 is fixed to the protruding end portion of the support shaft 11. Therefore, when the lever member 12 is rotated, the wastegate valve 10 is also rotated together. The lever member 12 is rotated by an electric actuator 13 fixed to the housing 3 via a bracket (not shown).

The electric actuator 13 includes a rod 23 that moves back and forth (horizontal movement), and the back-and-forth movement of the rod 23 is converted into rotation of the lever member 12 through rotation of the first arm 15 and the second arm 16. The first arm 15 extends in parallel with the lever member 12, and one end portion of the first arm 15 far from the lever member 12 is rotatably connected to the housing 3 by the first pin 17 . A tip member 24 provided at the tip of the rod 23 via a coil spring 22 is connected to the other end near the lever member 12 by a second pin 18 so as to be relatively movable. The first arm 15 has a pin hole 19 into which the second pin 17 is fitted. The pin hole 19 is a long hole extending in the longitudinal direction of the first arm 15. For this reason, the rotation of the first arm 15 is allowed.

The second arm 16 is also long in the same direction as the lever member 12, and its one end 16 a and the other end 16 b are formed in a U-shape in plan view protruding toward the first arm 15 and the lever member 12. . One end 16 a is fixed to the first arm 15, and the other end 16 b is connected to the lever member 12 by a third pin 20 so as to be relatively movable. The third pin 20 is fixed to the second arm 16, and the lever member 12 has a pin hole 21 into which the third pin 20 is fitted. The pin hole 21 is a long hole that is long in the longitudinal direction of the lever member 12. Thus, relative rotation between the second arm 16 and the lever member 12 is allowed.

Note that the second arm 16 can be directly rotated by the tip member 24 without using the first arm 15. Further, the lever member 12 can be directly rotated by the tip member 24 without using the first and second arms 15 and 16.

Coils spring 22, the adhesion tension spring between the lines that the coils are in close contact state with no load is used. Of course, it is also possible to use a spring in which there is a gap between the wires under no load.

In the present embodiment, the coil spring 22, the tip member 23, the first and second arms 15, 16 and the lever member 12 constitute the power transmission unit described in the claims, and a part of them is an elastic body. It is constituted by a coil spring 22 upcoming. The spring force of the coil spring 22 is set to such a strength that the arms 15 and 16 and the lever member 12 can be rotated without expansion and deformation in a normal state. Therefore, the wastegate valve 10 can be opened and closed by driving the electric actuator 13 to move the rod 23 back and forth.

If the electric actuator 13 fails for some reason and the rod 23 stops moving, and the internal pressure around the inlet 4 of the housing 3 becomes abnormally high with the wastegate valve 10 closed, as shown in FIG. By extending the coil spring 22, the wastegate valve 10 opens and moves. Accordingly, the coil spring 22 is set to have a strength to be expanded and deformed when a pressing force equal to or higher than a set value is applied to the waste gate valve 10 without being stretched and deformed in a state where the resistance is not applied to the waste gate valve 10. .

Thus, it is the order to exert safety function part of the power transmission unit with a simple structure of only replacing the coil spring 22, a high level of safety while the cost can be secured. When a line contact spring is used as the coil spring 22 as in the embodiment, there is an advantage that the opening movement of the waste gate valve 10 can be performed with good responsiveness.

In this embodiment, any one of the first arm 15, the second arm 16, and the tip member 24 is made of an elastic body such as spring steel, and the opening and turning of the wastegate valve 10 is caused by the bending deformation. It is also possible to allow.

When a coil spring is used as the elastic body, a compression coil spring may be used to allow the waste gate valve to open and rotate by compressive deformation. Furthermore, when the wastegate valve is a pivoting type, the pivoting support shaft and the rotation shaft (rod) of the actuator are connected by a concentric intermediate shaft, and the intermediate shaft is torsionally deformable (elastic body). Therefore, it is also possible to allow the wastegate valve to open and rotate.

Further, the opening / closing method of the wastegate valve is not limited to the rotary type, and various drive modes such as a slide type (shutter type) and a swing type that moves in the thickness direction can be adopted. How the elastic body is deformed may be appropriately set in consideration of the opening / closing method of the waste gate valve, the driving method of the actuator, and the like.

  As the electric actuator, an electric motor or an electromagnetic cylinder can be employed. These actuators may be attached to the housing of the exhaust turbocharger as in the embodiment, or may be attached to a member (for example, a cylinder head or a cylinder block) different from the exhaust turbocharger via a bracket or the like. Good. In terms of ease of handling by unitization, it can be said that the actuator is preferably attached to the housing of the exhaust turbocharger.

  The present invention can be actually applied to an exhaust turbocharger of an internal combustion engine and exhibits its function. Therefore, it can be used industrially.

DESCRIPTION OF SYMBOLS 1 Exhaust turbocharger 2 Exhaust passage 3 Housing which comprises exhaust turbocharger 6 Exhaust gas passage 7 Turbine 8 Bypass passage 10 West gate valve 12 Lever member 13 Electric actuator 15, 16 Arm 22 Coil as an example of elastic body Spring 23 Actuator rod 24 tip member

Claims (1)

A wastegate valve for controlling the amount of exhaust gas flowing toward the turbocharger turbine; and an actuator for opening and closing the wastegate valve; and the movement of a rod provided on the actuator is a power transmission It is a configuration that is transmitted to the wastegate valve through a section,
State during the preceding power transmission unit, the elastic body is a rod predetermined force to the waste gate valve in a state that does not move is deformed et bullet resistance acts allow dynamic opening of the wastegate valve, said rod moves Then, it is provided to transmit the movement of the rod to the wastegate valve without elastic deformation,
Internal combustion engine.

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