JPH0435537Y2 - - Google Patents

Description

[Detailed description of the invention] (Field of industrial application) The present invention forms a plurality of exhaust gas inlets in the turbine casing of an exhaust turbo supercharger, and connects the plurality of exhaust gas inlets to an appropriate valve device. Therefore, the present invention relates to an exhaust turbo supercharging device that can vary the passage area of the exhaust gas passage in the turbine casing by controlling opening and closing according to the operating state of the engine.

(Prior art) In a conventional exhaust turbo supercharger, a single exhaust passage is formed inside the turbine casing, and the passage area of the exhaust passage is fixedly set, and the exhaust passage area is fixedly set, and the exhaust passage area is fixedly set. The A/R value determines the turbine efficiency from the viewpoint of obtaining the highest level of turbine efficiency (A: passage area of the exhaust gas passage of the turbine casing, R: curvature of the scroll portion of the turbine casing). It was customary to set the radius) according to the amount of exhaust gas when the engine was operated at medium speed.

However, if the A/R value is set in accordance with the medium-speed operation of the engine, the amount of exhaust gas will be higher than the standard exhaust gas amount in the high-speed operation region of the engine. This increases the flow resistance of the exhaust gas, making it impossible to fully utilize the exhaust energy of the exhaust gas.Furthermore, on the engine side, the exhaust pressure increases, causing problems such as deterioration of combustibility and the inability to obtain sufficient engine output. On the other hand, in the low-speed operating range of the engine, the flow rate of exhaust gas decreases as the amount of exhaust gas becomes less than the above-mentioned standard exhaust gas amount, and the turbine wheel cannot rotate sufficiently, resulting in lower turbine efficiency. This will cause the problem of a decline.

In order to improve the drawbacks peculiar to an exhaust turbo supercharger equipped with a turbine casing having a single exhaust gas passage, as shown in FIG. 2 of the passage 102 and the second exhaust gas passage 103
The first exhaust gas passage 102 is divided into two exhaust gas passages.
By controlling the opening and closing of the exhaust gas passage by a valve device 105 provided on the exhaust pipe 104 side, the passage area of the exhaust gas passage can be made variable according to the operating condition of the engine, thereby achieving a high level of supercharging throughout the entire operating range of the engine. Attempts are being made to develop techniques to ensure performance (see, for example, Japanese Utility Model Publication No. 1230/1983).

In this known example, since the valve device 105 is configured to be opened against the pressure of the exhaust gas G, the gas of the exhaust gas is loaded on the valve body 106 when the valve device 105 is opened. The pressure causes a large pressure difference between the front and rear of the valve body 106, and therefore a large opening force is required. However, when the valve device 105 is opened, an annular fitting gap 109 is formed between the valve stem receiving hole 108 formed in the valve body 106 and the valve stem 107 before the valve body 106 is opened. The fitting gap 10 is opened to connect the exhaust gas passage 110 on the exhaust pipe 104 side and the first exhaust gas passage 102 on the turbine casing 101 side.
9, and the exhaust gas passages 11
A part of the exhaust gas G on the 0 side is transferred to the first exhaust gas passage 1.
02 side to reduce the pressure difference between the two, thereby reducing the opening force of the valve device 105.

However, in this case, the valve device 1
During the opening operation of valve 05, high-temperature exhaust gas G flows through the fitting gap 109, so that the valve stem receiving hole 10
The oxide film on the surface of valve 8 is removed and oxidation progresses rapidly, and the diameter of the valve stem receiving hole 108 is gradually expanded, and in some cases, the valve stem 107 and valve body 106 are
There is a risk that the valve device 105 may be damaged, such as by detachment.

In addition, the valve device 105 has an exhaust gas release function.
In order to increase the effect of reducing the opening force of the valve body 10, it is sufficient to make the fitting gap 109 larger. However, if the fitting gap 109 becomes too large, the valve body 10
There is a limit to increasing the fitting gap 109 because the floating width between the valve stem 107 and the valve stem 107 becomes excessive, and a new problem arises in that the positioning accuracy of the valve body 106 with respect to the valve seat surface 111 deteriorates. As a result, a sufficient opening force reduction effect cannot be obtained.

(Purpose of the invention) The present invention is an attempt to solve the problems pointed out in the above section of the prior art. The purpose of this invention is to reduce the operating force of the valve device without complicating the structure or impairing the durability and reliability of the device.

(Means for Achieving the Object) As a means for achieving the above object, the present invention provides an exhaust gas exhaust system that is equipped with a valve device that opens against the gas pressure of the exhaust gas in the exhaust gas passage leading to the turbine casing. In the turbo supercharging device, the above-mentioned valve device is formed in the above-mentioned exhaust gas passage and a valve support that can be swung from the downstream side of the exhaust gas toward the upstream side by an appropriate valve operating device when the valve is opened. a valve body that closes or opens the exhaust gas passage by seating or separating from the valve seat surface; A connection that connects the valve body and the distal end of the valve support body so that they overlap each other in the swinging direction of the valve support body and that the valve body and the tip end of the valve support body can approach and separate from each other within a predetermined range in the swinging direction. The valve body is formed by penetrating the valve body in its thickness direction within the overlapping range of the valve body with the valve support body and at a location other than the position where the connecting member is disposed, and The present invention is characterized in that a vent hole is formed that is open when the valve body and the tip end of the valve support body are separated from each other and is closed when they are in contact with each other.

(Function) In the present invention, the following effects can be obtained by the above-mentioned means.

(1) When the valve device swings the valve support from the exhaust gas downstream side to the upstream side, the valve is opened at the tip of the valve support and the valve disposed on the exhaust gas downstream side of the tip. Since the valve support body is connected to the valve support body by a connecting member so as to be able to move toward and away from it within a predetermined range in the swinging direction of the valve support body, at the initial stage of the valve opening operation, the valve is opened by the gas pressure of the exhaust gas. The valve support body is separated within the predetermined range from the valve body which is biased in the direction of seating on the seat surface, and a gap of a predetermined size is created between the two.

In this case, a vent hole is formed in the portion of the valve body that overlaps with the tip of the valve support body and in a region other than the location where the connecting member is arranged, passing through the valve body in the thickness direction. When the valve support is opened and a gap is created between the valve body and the tip of the valve support, the vent opens, and exhaust gas is exhausted from the upstream side of the valve body through the vent. Exhaust gas flows into the gas downstream side, and the pressure difference between the front and rear sides of the valve body is reduced as much as possible. As a result, compared to the case where the valve body is moved in the valve opening direction with a high pressure difference occurring before and after the valve body, the force required to open the valve of the valve device is reduced as much as possible.

(2) The vent hole formed in the valve body is formed in a portion where the valve body overlaps with the distal end portion of the valve support body, and in a portion other than the position where the connecting member is disposed, and where the valve body and the valve support body are in contact with each other. Since it is configured to be opened and closed by a separation action, the valve support and the valve will remain intact even if the inner circumferential surface of the communication hole becomes oxidized and its diameter increases due to the circulation of exhaust gas. The state of connection with the body is not affected in any way, so the valve function of the valve device is maintained well over a long period of time, and the reliability of its operation is increased.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 7.

Configuration Figures 1 to 3 show an exhaust turbo supercharging device according to an embodiment of the present invention, and the reference numeral 1 in the figure
is an engine body, 2 is an exhaust turbo supercharger (described in detail later), and the exhaust turbo supercharger 2 is fixed to an exhaust pipe 4 (described in detail later) via a gasket 3 (see Fig. 3). has been done.

As shown in FIG. 1, the exhaust turbo supercharger 2 includes a turbine casing 21 (described in detail later) containing a turbine wheel (not shown) and a compressor casing 22 containing a compressor wheel (not shown). They are connected via a center casing 23.

The turbine casing 21 is shown in FIGS.
As shown in the figures, a scroll-shaped exhaust gas passage formed inside the turbine casing 21 is separated into two exhaust gas passages arranged in the axial direction of the turbine casing 21 by a partition wall 26 extending in the direction of the scroll. , a first exhaust gas passage 27 having an oval cross section located on one side of the partition wall 26, and an oval cross section located on the other side of the partition wall 26 and having a smaller passage area than the first exhaust gas passage 27. The second exhaust gas passage 28 is divided into two left and right exhaust gas passages.
These two exhaust gas passages 27 and 28 have exhaust gas inlet ports 29 and 30 formed at the open ends on the exhaust gas upstream side of the turbine casing 21 which act as abutting surfaces toward the exhaust pipe 4 side. It is opened on the end face 21a on the gas upstream side. Of the two exhaust gas inlets 29 and 30, the first exhaust gas inlet 29 is always open throughout the entire operating range of the engine, but the second exhaust gas inlet 30
is closed by a valve device 6, which will be described later, when the engine is running at a low speed with a small flow rate of exhaust gas, and is opened when the engine is running at a high speed with a high flow rate of exhaust gas. Therefore, when the engine is running at low speed, the first
Only the exhaust gas inlet 29 is opened, and the exhaust gas is introduced into the scroll portion 21b side of the turbine casing 21 through the first exhaust gas passage 27. On the other hand, when the engine is operated at high speed, the first exhaust gas Both the inlet 29 and the second exhaust gas inlet 30 are open, and the exhaust gas flows from both the first exhaust gas passage 27 and the second exhaust gas passage 28 to the scroll portion 21b side of the turbine casing 21. It will be introduced.

In this case, in this embodiment, the partition wall 2 of the end surface 21a of the turbine casing 21
A substantially elongated annular portion located at the mouth edge of the second exhaust gas inlet 30 including the end surface 26a of the exhaust gas inlet 6 serves as a valve seat surface 33 for the valve device 6, which will be described later.

In this way, the end face 2 of the turbine casing 21
If part of 1a is used as the valve seat surface 33 of the valve device 6, the second exhaust gas inlet 30 will open facing the exhaust gas flow direction. Therefore, when the valve device 6 is in the open state, the exhaust gas flows smoothly into the turbine casing 21 in an almost straight line with low flow resistance without detouring, compared to when the exhaust gas flow is a detour flow. As a result, turbine efficiency is improved by the reduction in flow resistance.

In addition, in this case, the entire area of the opening of the second exhaust gas inlet 30 can effectively function as a flow path for exhaust gas, and therefore, for example, when the flow rate of exhaust gas is constant, the exhaust gas distribution direction and second
Compared to a structure in which the axial direction of the exhaust gas inlet 30 intersects with the axial direction of the second exhaust gas inlet 30, the diameter of the second exhaust gas inlet 30 can be made smaller, and accordingly, the valve device 6 can also be made smaller. This is advantageous in terms of making the device more compact.

Furthermore, since the planar direction of the valve seat surface 33 is substantially perpendicular to the exhaust gas flow direction, this is compared to the case where the planar direction of the valve seat surface 33 and the exhaust gas flow direction are substantially parallel. Therefore, the sealing performance on the valve seat surface 33 is good (that is, the valve device 6 described later
When the valve body 61 is seated on the valve seat surface 33, the extending direction of the sealing surface between them is perpendicular to the flow direction of the exhaust gas, and the flow resistance of the exhaust gas leaking along the sealing surface increases accordingly. Therefore, the exhaust gas flow control will be performed more reliably.

Further, since the partition wall 26 is formed in the turbine casing 21, the structure is more complicated and irregular thermal deformation is more likely than in the case of a turbine casing having a structure without the partition wall 26. In this embodiment, as will be described later, the valve device 6 is not placed on the turbine casing 21 side, but on the exhaust pipe 4 side, which has a relatively simple structure compared to the turbine casing 21 and is less prone to irregular thermal deformation. Since the turbine casing 21 is provided in the exhaust turbocharger equipped with the valve device 6, it is possible to minimize the complexity of the structure of the turbine casing 21. As a result, the increase in size can be suppressed as much as possible.

In FIG. 1, reference numeral 31 is a waste gate valve having a known structure provided on the side of the turbine casing 21, and the waste gate valve 31 is operated in response to intake pressure (supercharging pressure) of the engine. The opening/closing is controlled by the first actuator 8.

The exhaust pipe 4 is connected to an exhaust port of each cylinder of the engine body 1 (not shown) as shown in FIGS. 1 to 3.
A branch pipe section 41 consisting of four branch pipes 41A, 41B connected in a substantially horizontal direction to the
Then, the branch pipe portion 4 is assembled while the branch pipes 41A, 41B... are collected at the downstream end of the exhaust gas.
1 and a collecting pipe part 42 extending in a direction perpendicular to the branch pipe part 41, and the end surface 4a on the side of the branch pipe is connected to the engine main body 1.
It is fastened and fixed to the side part of the engine main body 1 in a state where the sides abut, and on the end surface 4b on the collecting pipe part 42 side (i.e., the upper end surface 42a of the collecting pipe part 42),
As shown in FIGS. 3 and 4, the turbine casing 21 of the exhaust turbo supercharger 2 is abutted and fixed via a gasket 3. As shown in FIGS.

A continuous portion 46 located at the exhaust gas upstream end of the collecting pipe portion 42 of the exhaust pipe 4 and continuing to the branch pipe portion 41 is defined by a projected line l ₁ in FIG. 4 and an imaginary line l ₂ in FIG. As shown in FIG.
(in the exhaust gas flow direction) facing the first exhaust gas inlet 29 and the second exhaust gas inlet 30 of the turbine casing 21 simultaneously and in a direction along the opening direction of each of the exhaust gas inlets 29 and 30; The opening has a substantially square cross section and has an opening area and an opening direction that can be obtained. Therefore, the exhaust gas collecting passage 43 in the collecting pipe section 42 and the first
The exhaust gas passage 27 and the exhaust gas passage on the turbine casing 21 side formed by the second exhaust gas passage 28 are continuous in a substantially coaxial manner,
Exhaust gas G flowing inside from the branch pipe section 41 side to the collecting pipe section 42 side is guided by the continuous section 46 and flows linearly within the collecting pipe section 42 along its axial direction, The first of the turbine casing 21
exhaust gas inlet 29 and second exhaust gas inlet 3
This allows for smooth introduction with almost no flow resistance on the 0 side.

Further, this exhaust pipe 4 has a side wall 4 of the side wall of the collecting pipe portion 42 on the side facing the second exhaust gas inlet 30 of the turbine casing 21.
8 is bulged outward by an appropriate amount from the continuous portion 46 at a position closer to the end surface 4b, and is located inside thereof in a continuous manner with the exhaust gas collecting passage 43 and on the side thereof, and has one end thereof The expansion portion 44 has an expansion space 45 of an appropriate size that opens on the end surface 4b. This expanded portion 44 functions as an attachment and storage space for a valve device 6, which will be described later.

The valve device 6 is attached to the expanded portion 44 of the exhaust pipe 4 as shown in FIGS. 4 to 7, and is connected to the second exhaust gas inlet 30 of the turbine casing 21.
Particularly in this embodiment, the present invention is applied to make the valve device 6 a swing type valve device as described later. That is, the valve device 6
As shown in FIG. 5, the expanded portion 44 of the exhaust pipe 4 is
Moreover, of the pair of side walls facing each other in the longitudinal direction of the second exhaust gas inlet 30 of the turbine casing 21, the side wall 47 located on the side opposite to the engine main body 1 is moved inwardly and outwardly (in other words, The operating center axis 6 of the exhaust gas inlet 30 is attached to a bearing tube 66 that is provided through the exhaust gas inlet 30 (in a direction parallel to the long axis direction).
5 rotatably supported, and a valve holding plate 63 formed at the swinging end 62a of the valve support 62 (corresponding to the tip of the valve support in the scope of the utility model registration claim). The valve body 61 is supported in a floating manner (that is, freely movable toward and away from the valve body) via a pair of connecting pins 67 and 68 (corresponding to the connecting member in the claims of the utility model registration). .

The valve body 61 is connected to the valve seat surface 33 formed at the mouth edge of the second exhaust gas inlet 30 on the end surface 21a of the turbine casing 21, as shown in FIG.
The plate is an elliptical plate having a size that can at least close the second exhaust gas inlet 30 and cover the end surface 26a of the partition wall 26 of the turbine casing 21 when the plate is brought into contact with the turbine casing 21. Further, in the central portion in the longitudinal direction, a vent hole 71 of an appropriate diameter is formed to penetrate the valve body 61 in its thickness direction by applying the present invention.

In this way, when the end face 26a of the partition wall 26 is covered by the valve body 61 when the valve device 6 is in the closed state, thermal oxidation or cracking of the partition wall 26 may occur as described later. The thermal deterioration phenomenon is suppressed as much as possible, and the flow resistance of exhaust gas is also reduced. That is, when the valve device 6 is in the closed state, the end surface 2 of the partition wall 26 is closed by the valve body 61.
When the end face 26a is covered, the frequency at which the end face 26a is directly exposed to high-temperature exhaust gas is reduced compared to a structure in which the end face 26a is directly exposed to exhaust gas throughout the entire operating range of the engine. (Note that the rate at which the valve device 6 is closed throughout the entire operating range of the engine is normally approximately 70 to 80%.
%), thermal oxidation near the end face of the partition wall 26 is prevented as much as possible.

Furthermore, since the temperature rise of the partition wall 26 is suppressed, the occurrence of cracks due to thermal stress in the vicinity of the end face of the partition wall 26 is prevented.
This results in improved durability.

Furthermore, since thermal oxidation and crack generation near the end faces of the partition walls 26 are prevented as described above, it is possible to reduce the thickness of the partition walls 26. Therefore, the turbine casing 21
This is advantageous in terms of improving supercharging performance, as the weight and size of the pump is promoted, and the flow resistance of exhaust gas when the valve device 6 is in the open state is reduced by the thinner partition wall 26. It is.

On the other hand, the pair of connecting pins 67 and 68 connecting the valve body 61 and the valve holding plate 63 of the valve support 62 are arranged so as not to interfere with the ventilation hole 71, as shown in FIGS. 6 and 7. The upper surface 6 of the valve body 61 is fixed at appropriate intervals in the longitudinal direction of the valve body 61.
Fitting shaft portions 67a and 68a protruding toward 1a side are freely fitted into pin receiving holes 72 and 72 formed in the valve holding plate 63 of the valve support 62, respectively.

Further, the length dimensions of the fitting shaft portions 67a, 68a of the pair of connecting pins 67, 68 are the same as those of the valve body 61.
The valve holder plate 63 is made to be longer than the thickness of the valve holder plate 63 by an appropriate length so that the valve holder plate 63 and the valve holder plate 63 can be supported in a mutually floating manner. Therefore, when opening the valve device 6 from its closed state (the state shown in FIG. 6), there is a gap between the valve body 61 and the valve holding plate 63 as shown in FIG. 7 at the beginning of the valve opening operation. A parallel gap 74 communicating with the vent hole 71 is formed, and the second exhaust gas passage 28 of the turbine casing 21 and the exhaust gas collective passage 43 of the exhaust pipe 4 are connected through the vent hole 71 and the gap 74. They will be able to communicate with each other.

Therefore, when the valve device 6 is rotated from its closed state in the direction of arrow A (see FIG. 4) to open the valve as shown in FIG. 6, the static pressure of the exhaust gas is and dynamic pressure is applied to the upper surface 61a of the valve body 61.
Since the load is applied to the valve side, a large actuation force is required to open the valve body 61 against the pressure of the exhaust gas, but in this embodiment, the valve body 61 is Since the valve body 61 is supported in a floating manner on the support body 62 and has a vent hole 71 formed in the valve body 61, the valve body 61 and the valve retaining plate are connected at the initial stage of opening of the valve device 6, as shown in FIG. 63 are separated from each other, and the high pressure exhaust gas collection passage 43 and the low pressure second exhaust gas passage 28 are communicated with each other. Therefore, part of the exhaust gas flows into the second exhaust gas passage 28 side through the vent hole 71, and the pressure difference between the two is reduced as much as possible (in other words, the opening to the valve body 61 is reduced). (The valve direction regulating force is reduced), and the valve device 6 can be opened smoothly and quickly with a smaller valve opening operation force. As a result, downsizing of the valve operating device 7, which will be described later, is facilitated, and the wear resistance of the operating center shaft 65 or the bearing sleeve 66 is improved.

Further, in this case, each pin receiving hole 72, 72 of the valve holding plate 63 is connected to the connecting pin 67, 68, respectively.
Since the heads 67b and 68b of the exhaust gas collecting passage 43 are substantially closed, the second
Exhaust gas flowing out to the exhaust gas passage 28 side flows into the vent hole 71 side from the gap 74 between the valve body 61 and the valve holding plate 63 without passing through the pin receiving holes 72, 72. . For this reason, each pin receiving hole 72, 7 plays an important role in valve function.
This prevents the inner circumferential surface of the valve device 6 from being exposed to high temperature exhaust gas and thermally deteriorating, resulting in an excessive amount of free movement between the valve body 61 and the valve support body 62, which impairs the function of the valve device 6. Prevented.

In other words, since the vent hole 71 is not involved in any way in the connection structure between the valve body 61 and the valve support body 62, even if the vent hole 71 is oxidized by the exhaust gas flowing through it. Even if the diameter of the valve device 6 is increased, the operating characteristics of the valve device 6 will not be affected in any way, and good valve operating characteristics will be maintained over a long period of time. Further, even if exhaust gas flows through the vent hole 71 when the valve is opened, this exhaust gas is branched from the main stream in the exhaust passage and flows into the gap between the valve body 61 and the valve support body 62. Therefore, the oxidizing effect of the vent hole 71 itself is less than when high-temperature, high-pressure mainstream exhaust gas flows directly.

In addition, since the valve body 61 and the valve holding plate 63 are connected to each other so as to be able to freely float, for example, if the gasket 3 interposed between the exhaust pipe 4 and the turbine casing 21 collapses due to aging, Even if the valve body 61 or the valve seat surface 33 is worn out due to long-term use, the valve body 61 will float and displace following the changing state of the relative relationship between the two, and the valve body 61 and the valve seat surface 33 will be The adhesion, that is, the sealing performance, is maintained well over a long period of time.

Furthermore, in this valve device 6, the valve body 61 and the valve holding plate 63 are connected to a pair of connecting pins 67, 6.
8, the relative positioning of the valve body 61 and the valve holding plate 63 in the plane direction is easy, and the once set relative position does not shift during use (the valve body 61 Securing positioning function). Therefore, it is possible to make the valve body 61 oval instead of circular, and it is possible to make the valve body 61 even more compact than when the valve body 61 is circular. .

Further, the advantage that the positioning of the valve body 61 is easy and the positional deviation does not occur can be obtained by forming the opening shape of the second exhaust gas inlet 30 not in a circle but in an oval shape as described above. , while keeping the relative distance between the second exhaust gas inlet 30 and the operating center axis 65 of the valve device 6 as small as possible, and also increasing the opening area of the second exhaust gas inlet 30 as much as possible. This makes it possible to increase the As a result, compared to the case where the valve body 61 or the second exhaust gas inlet 30 is circular, the distance between the second exhaust gas inlet 30 and the operation center axis 65, that is, the arm of the valve support 62 It becomes possible to reduce the valve opening force of the valve device 6 by making the length as short as possible (that is, light and smooth operation of the valve device 6 is realized). That is, in this embodiment, the ability to shorten the arm length of the valve support body 62 in this way and the formation of the vent hole 71 in the valve body 61 as described above combine to reduce the opening of the valve device 6. The operating force is further reduced.

On the other hand, this valve device 6 has a valve operating device 7 which will be described later.
Accordingly, arrow A is centered on the operation center axis 65.
- The valve is rotated in the B direction, and the valve is in the closed position shown by the solid line in FIG.
In this case, in the open position of the valve device 6, the valve device 6 is housed in the expansion space 45 of the exhaust pipe 4. (In other words, it is located closer to the extended portion 44 than the projection line l ₁ of the continuous portion 46)
As such, the arm length of the valve support 62, the mounting position of the operating center shaft 65, etc. are set appropriately.

By doing so, when the valve device 6 is in the open state, the passage area of the exhaust gas collecting passage 43 of the exhaust pipe 4 is substantially reduced by the valve device 6 positioned at the valve open position. Therefore, the flow resistance of the exhaust gas is reduced as much as possible, and when the valve device 6 is in the closed state, the valve support 62 and the operating center shaft 65 (substantially The bearing sleeve 66) prevents the exhaust gas from directly hitting the exposed portion of the end surface 21a of the turbine casing 21 facing the expansion space 45 as much as possible, thereby preventing thermal deterioration of the end surface 21a. suppressed. From this, the durability of the turbine casing 21 is improved.

Further, since the valve device 6 is provided on the exhaust pipe 4 side, where the partition wall 26 is not formed and the structure is relatively simple, and therefore there is less irregular thermal deformation, the structure is relatively complex and the structure is relatively simple, and therefore the valve device 6 has a relatively simple structure and is therefore less prone to irregular thermal deformation. Compared to the case where the valve device 6 is provided on the turbine casing 21 side where thermal deformation is likely to occur, the effect of thermal deformation on the operating characteristics of the valve device 6 is smaller, and the operating accuracy of the valve device 6 is maintained at a higher level. It becomes possible to do so.

The valve actuating device 7 opens and closes the valve device 6 according to the operating state of the engine, and moves its actuator 10 forward and backward in response to air pressure that is appropriately controlled to be supplied depending on the operating state of the engine. It is composed of a second actuator 9 having a diaphragm-type pressure responsive mechanism for displacing the first actuator.
As shown in the figures, it is attached to the side of the collecting pipe section 42 of the exhaust pipe 4 in a substantially adiabatic manner as will be described later. That is, in the collecting pipe part 42 of the exhaust pipe 4, an exhaust pipe insulator 12 made of a plate bent into a substantially U-shape is provided, excluding the side surface of the collecting pipe part 42 facing the engine main body 1 side. The collecting pipe portion 42 surrounds the outside of the other three sides.
A pair of mounting bolts 15 connects the insulator mounting portion 42b that is fitted from the outside and is bulged on one side of the collecting pipe portion 42 and the one side 12a of the actuator insulator 11 that faces the insulator mounting portion 42b. , 15.

Further, when installing the exhaust pipe insulator 12, the flat bracket 13 is attached to the tip end 13 of the exhaust pipe insulator 12.
a is projected outwardly from the outer end of the exhaust pipe insulator 12 on the side opposite to the engine main body 1, and is fastened together with the mounting bolts 15, 15. Furthermore, the second actuator 9, whose outer periphery is enclosed by the actuator insulator 11 in the shape of a substantially airtight container, is attached to the tip 13a of the bracket 13 on the actuator 10 side of the actuator insulator 11. The one side surface 11a is sandwiched between the tip 13a of the bracket 13 and the front end surface 9a of the second actuator 9, and is fastened and fixed by a pair of mounting bolts 16, 16.

Therefore, the second actuator 9 is connected to the actuator insulator 11 and the exhaust pipe insulator 1 with respect to the collecting pipe portion 42 of the exhaust pipe 4.
It will be fixed in a substantially adiabatic manner via the two members No. 2. The operating center shaft 65 of the valve device 6 is connected to the operating element 10 of the second actuator 9 mounted on the exhaust pipe 4 side through link levers 69 and 70. protrudes in the direction of arrow a (see Fig. 1), the valve device 6 rotates in the direction of arrow A (see Fig. 4), and the second exhaust gas inlet 30 is opened. When the actuator 10 moves backward in the direction of arrow b, the valve device 6 rotates in the direction of arrow B, and the second exhaust gas introduction port 30 is closed.

In this way, the exhaust pipe insulator 12 is attached to the outside of the exhaust pipe 4, and the actuator insulator 11 is attached to the tip 13a of the bracket 13, which is attached together with the exhaust pipe insulator 12 to the exhaust pipe 4 side. The encapsulated second actuator 9 is attached to its end surface 9a.
When the actuator insulator 11 is interposed between the bracket tip 13a and the insulators 11 and 12 are tightened together, the insulators 11, 12
This action prevents radiant heat from being transferred from the exhaust pipe 4 side to the second actuator 9 side as much as possible, and also prevents conductive heat transfer from the exhaust pipe 4 side via the bracket 13 to the actuator insulator 11. The amount of heat transferred to the second actuator 9 side is reduced as much as possible. Furthermore, when the entire circumference of the second actuator 9 is covered with the actuator insulator 11 as described above, the second actuator 9 is protected from collisions with flying stones, adhesion of sludge or rainwater, etc.
Actuator 9 can be protected. For these reasons, the durability of the second actuator 9 is improved.

Furthermore, since the temperature rise of the second actuator 9 is suppressed as much as possible as described above, the material of the diaphragm (not shown) of the second actuator 9 can be made of a low-grade material with relatively poor heat resistance. Therefore, the cost of the second actuator 9 can be reduced accordingly.

Further, the valve device 6 and a second valve device that operates the valve device 6 are provided.
Since both the actuator 9 and the actuator 9 are attached to the exhaust pipe 4 side, even if the exhaust pipe 4 is thermally deformed due to the influence of heat from exhaust gas, the second actuator 9 attached to the exhaust pipe 4 The relative relationship between the actuator 9 and the valve device 6 can be kept substantially constant, and the control accuracy of the valve device 6 can be maintained at a high level at all times. Furthermore, since both the valve device 6 and the second actuator 9 are attached to the exhaust pipe 4, the valve device 6 and the second actuator 9 are
This can be done while the actuator 9 is interlocked with each other, and its operation can be inspected with high precision in either the disassembled or assembled state of the device.
The assembly accuracy and ease of assembly between the second actuator 9 and the second actuator 9 are made good.

Operation and Effects Next, the operation and effects of this exhaust turbo supercharging device will be explained.

When the engine is operated, exhaust gas G discharged from each cylinder on the engine main body 1 side passes through each branch pipe 41A, 41B of the exhaust pipe 4 to the collecting pipe section 42.
After that, the exhaust gas passages in the turbine casing 21 of the exhaust turbo supercharger 2, that is, the first exhaust gas passage 27 and the second exhaust gas passage 28, are The exhaust energy is used to drive the turbine wheel, and the compressor wheel prepresses the intake air (intake supercharging).
At this time, the valve device 6 is opened and closed depending on the operating state of the engine, and the introduction form of the exhaust gas is selected.
That is, when the operating state of the engine is in a low-speed operating region where the flow rate of exhaust gas is low, the second actuator 9 moves the valve device 6 to the valve open position (see FIG. 4).
Conversely, when the engine operating state is in a high-speed operation region where the flow rate of exhaust gas is high, the second actuator 9 moves the valve device 6 to the open position (the position shown by the chain line in FIG. 4). ) is set. Therefore, in the low-speed operating range of the engine where the amount of exhaust gas discharged is small, the exhaust gas flows only from the first exhaust gas passage 27 to the turbine casing 2.
1, the exhaust gas is introduced into the turbine casing 21 even though the amount of exhaust gas is small.
The gas flow rate within the engine is sufficiently ensured, the rotation of the turbine wheel is maintained on the high rotation side, and it becomes possible to obtain the supercharging effect by the exhaust turbo supercharger 2 from a lower speed range. Furthermore, in this case, the passage area of the exhaust gas passage is the same as that of the first exhaust gas passage 27 and the second exhaust gas passage.
Since both of the exhaust gas passages 28 of the turbine casing 21 are narrowed down than when both are effective,
The difference between the exhaust gas pressure at the exhaust inlet side and the exhaust gas pressure at the exit of the scroll section can be made larger (that is, the expansion ratio of the exhaust gas increases), and a higher level of supercharging performance can be obtained. It will be.

On the other hand, in the high-speed operating range of the engine where a large amount of exhaust gas is emitted, both the first exhaust gas passage 27 and the second exhaust gas passage 28 are opened, so a large amount of exhaust gas is simultaneously transmitted to the turbine from both of them. It can be smoothly introduced into the casing 21 without causing large flow resistance. Therefore, the exhaust energy of a large amount of exhaust gas is effectively used as driving force for the turbine wheel, improving supercharging performance, and since the exhaust pressure on the engine side is reduced, its combustibility is improved, This will result in higher engine output.

The valve device 6 of the present invention may be controlled by directly detecting, for example, the flow rate of exhaust gas, the amount of intake air into the engine, etc., or may be controlled according to the engine speed in an operating region where the engine load is relatively high. etc., the control signal and control area are not limited.

(Effects of the invention) The exhaust turbocharging device of the present invention is provided with a valve device that opens against the gas pressure of exhaust gas in the exhaust gas passage leading to the turbine casing. The device is attached to a valve support body that is pivoted from the exhaust gas downstream side to the upstream side by an appropriate valve operating device when the valve is opened, and a valve seat surface formed in the exhaust gas passage. A valve body that closes or opens the exhaust gas passage by being seated or separated from the valve body, and a swinging motion of the valve support with respect to a surface on the downstream side of the exhaust gas at the tip of the valve support. a connecting member that connects the valve body and the distal end of the valve support body in a state where they overlap each other in the direction and in the swinging direction so that the valve body and the tip end of the valve support body can approach and separate from each other within a predetermined range; The valve body is formed in a region where the body overlaps with the valve support body and at a location other than the position where the connection member is disposed, passing through the valve body in the thickness direction, and connecting the valve body and the tip of the valve support body. A vent hole is formed that is open when the device is separated from the device and closed when it is in contact with the device.

Therefore, according to the exhaust turbocharging device of the present invention, the following effects can be obtained.

(1) The valve body and the tip of the valve support are connected by a connecting member so that they can move toward and away from each other within a predetermined range in the swing direction of the valve support, and the valve body and the distal end of the valve support are connected so that they can move toward and away from each other within a predetermined range. Since a vent hole is formed in the valve body to open and close the valve, when the valve device opens and closes,
Since the vent is opened prior to the opening operation of the valve body, the pressure difference between both sides of the valve body is reduced as much as possible, and the reduction of the valve opening operation force of the valve device is promoted. .

(2) Since the structure allows exhaust gas to flow through a vent hole that is provided in the valve body and opens and closes as the valve body and the valve support move toward and away from each other, even if the vent hole is oxidized by the exhaust gas, Even if the diameter of the valve is enlarged, there is no effect on the valve function of the valve device itself (in fact, it is very convenient for promoting the flow of exhaust gas), and conventional valve devices (for example, The durability and operational reliability of this valve are improved compared to a valve system (see Japanese Patent No. 1230) in which exhaust gas is allowed to flow through the valve stem receiving hole, which is directly related to the valve function.

(3) A vent hole is formed in the valve body, and this is opened and closed by the movement of the valve body and the valve support body. (There is no change in the relative relationship between the valve body and the valve support body), the diameter of the vent hole can be set relatively roughly, and the valve stem formed on the valve body as in the above conventional example It is easier to manufacture and has a simpler structure than a valve in which the valve function depends on the diameter of the receiving hole and the flow state of exhaust gas also changes.

[Brief explanation of the drawing]

FIG. 1 is a front view of an exhaust turbo supercharging device according to an embodiment of the present invention, FIG. 2 is a view taken along the - arrow in FIG.
Fig. 3 is a -arrow view of Fig. 1, Fig. 4 is a -sectional view of Fig. 3, Fig. 5 is a -sectional view of Fig. 4, and Fig. 6 is a -sectional view of Fig. 5; 7 is a state change diagram of the valve device shown in FIG. 6, and FIG. 8 is a structural explanatory diagram of a turbine casing portion of a conventional exhaust turbo supercharging device. 1...Engine body, 2...Turbo supercharger, 4
...Exhaust pipe, 6...Valve device, 7...Valve actuation device,
8, 9... Actuator, 11, 12... Insulator, 21... Turbine casing, 22
... Compressor casing, 23 ... Center casing, 26 ... Partition wall, 27, 28 ... Exhaust gas passage, 29, 30 ... Exhaust gas inlet, 31
...Waste gate valve, 33...Valve seat surface, 4
DESCRIPTION OF SYMBOLS 1... Branch pipe part, 42... Collection pipe part, 44... Expansion part, 61... Valve body, 62... Valve support body, 63...
... Valve holding plate, 65 ... Operation center axis, 71 ...
...vents.

Claims (1)

[Scope of utility model registration request] In an exhaust turbo supercharging device that is provided with a valve device that opens against the gas pressure of the exhaust gas in the exhaust gas passage leading to the turbine casing, the valve device includes:
A valve support body that is pivoted from the exhaust gas downstream side toward the upstream side by an appropriate valve actuation device when the valve is opened, and is seated or separated from a valve seat surface formed in the exhaust gas passage. By doing so, the valve body that closes or opens the exhaust gas passage and the valve body are mutually aligned in the swinging direction of the valve support with respect to the exhaust gas downstream side surface of the tip of the valve support. a connecting member that connects the valve body and the distal end of the valve support body so that they can approach and separate from each other within a predetermined range in the swinging direction, and Within the area of polymerization with the valve support and at a location other than the location of the connecting member,
A vent hole is formed to penetrate the valve body in its thickness direction, and is opened when the valve body and the tip of the valve support body are separated from each other, and is closed when they are in contact with each other. An exhaust turbo supercharging device characterized by: