JPH0435538Y2 - - 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 set fixedly. 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 turbocharger equipped with a turbine casing having a single exhaust gas passage, for example, as shown in FIG. and is divided into two exhaust gas passages, a first exhaust gas passage 103 and a second exhaust gas passage 104, and the first exhaust gas passage 103
A valve device 110 for opening and closing the first exhaust gas passage 103 is disposed on the side, and the valve device 110 opens and closes the first exhaust gas passage 103 during low speed operation of the engine.
is closed to allow exhaust gas to be introduced only through the second exhaust gas passage 104, whereas when the engine is running at high speed, the first exhaust gas passage 103 is opened and exhaust gas is introduced through the first exhaust gas passage 103 and the second exhaust gas passage 104. The passage area of the exhaust gas passage of the turbine casing 101 can be made variable according to the operating condition of the engine, and a high level of supercharging performance can be achieved throughout the entire operating range of the engine. Attempts are being made to develop technology that will enable this (for example, see Japanese Utility Model Publication No. 1230-1983).

However, in this known example, the partition block 1 is formed on the exhaust pipe 105 side so as to be continuous with the partition wall 102 of the turbine casing 101.
A part of the end face 106a on the upstream side of the exhaust gas of 06 and a part of the side wall 105a of the exhaust pipe 105 are used as the valve seat surface 107 for the valve body 111 of the valve device 110. Seat surface 107
In the seated state, the portion of the end surface 106a of the partition wall block 106 other than the portion acting as the valve seat surface 107 is directly exposed to the exhaust gas passage, so this exposed portion is continuously exposed to high temperatures during engine operation. As a result, the exhaust gas G is directly exposed to the exhaust gas G, and as a result, it collapses in a short period of time due to thermal oxidation or crack generation, impairing the sealing performance of the valve device 110, deteriorating the supercharging performance, and causing the exhaust pipe to deteriorate. 105 (if the valve seat surface 107 is formed on the turbine casing 101 side, the durability of the turbine casing 101) may be impaired.

In order to suppress such thermal deterioration phenomena such as thermal oxidation or crack generation, the wall thickness of the partition block 106 (the partition wall 102 in the case where the valve seat surface is formed on the turbine casing 101 side) should be increased. It is effective to improve heat dissipation by
Bulkhead block 106 exposed in the exhaust gas passage
Increasing the wall thickness of the partition wall 102 (or the partition wall 102) increases the flow resistance of exhaust gas, which is not a good idea from the viewpoint of supercharging performance.

(Purpose of the invention) The present invention is an attempt to improve the problems pointed out in the above section of the prior art. An object of the present invention is to provide an exhaust turbo supercharging device that improves the durability of a turbine casing while suppressing thermal deterioration of the turbine casing.

(Means for Achieving the Object) As a means for achieving the above object, the present invention provides a turbine casing having a plurality of exhaust gas inlets separated from each other by partition walls, and a turbine casing having a plurality of exhaust gas inlets separated from each other by partition walls. A common exhaust pipe including an exhaust gas collection passage for guiding exhaust gas and connected to the turbine casing, and a common exhaust pipe provided in the exhaust pipe to additionally collect exhaust gas on the high-speed side of the engine among the plurality of exhaust gas inlets provided in the exhaust pipe. In an exhaust turbo supercharging device equipped with a valve device for opening and closing an inlet for high-speed exhaust gas to be introduced, the valve device has an end face of the inlet for high-speed exhaust gas as a valve seat surface, and a valve seat face for the above-mentioned high-speed exhaust gas inlet. The valve body is configured to open toward the upstream side of the exhaust gas, and in the closed state, the valve body abuts the end face of the high-speed exhaust gas inlet and at least one of the partition walls It is characterized in that it is constructed so as to cover the entire area of the central portion of the exhaust gas collecting passage in the exhaust gas flow direction.

(Function) In the present invention, by the above-mentioned means, at least the end face facing the exhaust gas flow of the partition wall formed on the turbine casing side and functioning as the valve seat face of the valve device is located near the center of the exhaust gas collecting passage. When the valve device is in the closed state, the entire area of the part with the highest heat load is covered by the valve body from the exhaust gas flow, and the valve body is located on the upstream side of the exhaust gas with respect to the valve seat surface. This prevents exhaust gas from entering between the end face of the partition wall and the valve body, so that direct contact between the end face of the partition wall and the exhaust gas is almost completely cut off, and as a result, the end face of the partition wall and the valve body are almost completely cut off from each other. The temperature rise is smaller than when the end face is directly exposed to exhaust gas throughout the entire operating range of the engine, and thermal deterioration phenomena such as cracks due to thermal oxidation or thermal stress in the vicinity of the end face of the partition wall are suppressed accordingly. It will not be done.

In addition, the valve body covers only the part of the end face of the partition wall that has the greatest heat load, that is, the entire area near the center of the exhaust gas collection passage, where there is little influence of heat radiation from the passage wall and a large amount of high-temperature exhaust gas flows. This makes it possible to more effectively prevent thermal deterioration of the partition wall while suppressing the flow resistance of exhaust gas due to the valve body as much as possible.

Furthermore, by reducing the frequency with which the end faces of the partition walls are directly exposed to exhaust gas, temperature rises in the partition walls are suppressed. Compared to a structure in which the temperature rise of the partition wall is suppressed and thermal deterioration of the partition wall is reduced, the partition wall can be made thinner, and as a result, the turbine casing can be made smaller and lighter. It is something.

(Embodiment) Hereinafter, a preferred embodiment of the present invention will be described with reference to FIGS. 1 to 9.

(Structure) 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 figures
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) that houses a turbine wheel (not shown) and a compressor casing 22 that houses 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
The second exhaust gas inlet includes a narrow linear portion located near the center in the longitudinal direction of the end surface 26a of the exhaust pipe 4 (that is, a portion corresponding to the center of the exhaust gas collection passage 43 of the exhaust pipe 4, which will be described later). A substantially elongated annular portion located at the mouth edge of the valve 30 serves as a valve seat surface 33 for a 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 plate 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.
In particular, in this embodiment, the valve device 6 is constituted by a swing type valve device, as will be described later. That is, as shown in FIG. 5, the valve device 6 is connected to the side wall of the expanded portion 44 of the exhaust pipe 4 and the second exhaust gas inlet 30 of the turbine casing 21 facing away from the engine in the longitudinal direction. The operating center axis of the bearing tube 66 is provided by penetrating the side wall 47 located on the main body 1 side in the inner and outer directions (in other words, in the direction parallel to the long axis direction of the second exhaust gas inlet 30). 65 rotatably supported, and the valve support 62.
The valve body 61 is supported in a freely floating manner via a pair of connecting pins 67 and 68 with respect to a valve holding plate 63 formed at a swing end 62a of the valve body 61.

As shown in FIG. 5, the valve body 61 is formed on the valve seat surface 3 formed at the edge of the second exhaust gas inlet 30 on the end surface 21a of the turbine casing 21.
3, at least the second exhaust gas inlet 30 is closed, and at the same time, the entire narrow portion of the end face 26a of the partition wall 26 of the turbine casing 21 near the center in the longitudinal direction is closed. It is an elliptical plate with a size that allows it to be covered, and a vent hole 71 of an appropriate diameter is formed in the central part in the longitudinal direction of the plate, passing through the valve body 61 in its thickness direction. .

In this way, when the valve device 6 is in the closed state, the portion of the end surface 26a of the partition wall 26 that is exposed to the largest amount of exhaust gas and therefore has a high thermal load is covered by the valve body 61 from the exhaust gas. In this case, as will be described later, thermal deterioration phenomena such as thermal oxidation or crack generation of the partition wall 26 are suppressed as much as possible, and the flow resistance of exhaust gas is also reduced.

That is, if 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, the frequency at which the end face 26a portion is directly exposed to high-temperature exhaust gas will be reduced. This is significantly reduced compared to an engine configured to be directly exposed to exhaust gas throughout the entire operating range (note that the rate at which the valve device 6 is closed throughout the entire operating range of the engine is normally approximately 70%). (up to 80%), thermal oxidation in the vicinity of 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, and the durability of the turbine casing 21 is thereby improved. It will be improved. 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 is made lighter and more compact, 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, which improves supercharging performance. This is advantageous in terms of improving performance.

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 body 62 are connected to the valve body 61 as shown in FIGS. 6 and 7. A pin receiving hole 7 is formed in the valve holding plate 63 of the valve support body 62, and has fitting shaft portions 67a and 68a which are fixed to the valve holding plate 63 of the valve support body 62 at appropriate intervals in the longitudinal axis direction of the valve support body 61, and have fitting shaft portions 67a and 68a that protrude toward the upper surface 61a.
2, 72 so as to be freely movable. Moreover, the above-mentioned fitting shaft portion 67 of this pair of connecting pins 67, 68
The length of a, 68a is set to be longer than the thickness of the valve retainer plate 63 by an appropriate length so that the valve body 61 and the valve retainer plate 63 can be supported so as to be able to float relative to each other. Therefore, when the valve device 6 is opened from its closed state (the state shown in FIG. 6), the valve body 61 and the valve retaining plate 63 are connected to each other as shown in FIG. 7 at the beginning of the valve opening operation.
In between, there is a parallel gap 7 communicating with the ventilation hole 71.
4 is formed, and the second exhaust gas passage 28 of the turbine casing 21 and the exhaust gas collecting passage 43 of the exhaust pipe 4 are made to communicate with each other via the ventilation hole 71 and the gap 74.

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 actuation force (that is, the valve actuation device 7, which will be described later, is miniaturized and its operation is reduced). (The wear resistance of the central 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 addition, since the valve body 61 and the valve retaining plate 63 are connected to each other so as to be able to freely float, for example, the gasket 3 interposed between the exhaust pipe 4 and the turbine casing 21 may become flat 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 displaced. The adhesion, that is, the sealing performance, with the material will be 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 more compact than when the valve body 61 is circular. It is.

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. 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 central axis of operation can be increased. 65, that is, the arm length of the valve support 62, can be made as short as possible to reduce the valve-opening force of the valve device 6 (that is, the valve device 6 can be opened easily and smoothly). operation 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.

Furthermore, in this embodiment, as shown in FIGS. 6 and 7, a vent hole 71 formed in the valve body 61 is opened and closed by utilizing the floating function of the valve body 62, thereby opening and closing the vent hole 71 formed in the valve body 61. In order to reduce the operating force when opening the valve, in addition to this configuration, for example, as shown in FIGS. Consists of pins,
When the valve device 6 is in the closed state (see Fig. 8), the valve body 6
While ensuring close contact with the valve seat surface 33 of 1,
At the beginning of the opening operation (see FIG. 9), the valve body 61 is opened from one side in the longitudinal direction by utilizing the difference in length between the pair of connecting pins 67 and 68. Even if an inclined gap 75 is formed between the valve seat surface 33 and a part of the exhaust gas is released from the gap 75 to the second exhaust gas passage 28 side, the same effect as in the case of the above structure can be obtained. Effects can be obtained.

Each member in FIGS. 8 and 9 has the same configuration as each member in FIGS. 6 and 7, and the reference numerals assigned to each member in FIGS. 6 and 7 are the same. Detailed explanation thereof will be omitted by assigning the same reference numerals.

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 or the mounting position of the operating center shaft 65 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. An insulator mounting portion 42b is fitted from the outside of the collecting pipe portion 42 so as to surround the outside of the other three side surfaces, and is bulged on one side of the collecting pipe portion 42, and faces the insulator mounting portion 42b. It is fixed by fastening one side 12a of the actuator insulator 11 with a pair of mounting bolts 15, 15. Furthermore, when installing this exhaust pipe insulator 12, a flat bracket 13 is attached together with the exhaust pipe insulator 12.
are fixed together by the mounting bolts 15, 15, with the distal end 13a protruding outward from the outer end of the exhaust pipe insulator 12 on the side opposite to the engine body 1.

Furthermore, the tip 13a of the bracket 13 is provided with the second insulator, the outer periphery of which is covered by the actuator insulator 11 having a substantially airtight container shape.
The actuator 9 is connected to one side surface 11a of the actuator insulator 11 on the actuator 10 side.
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.

Next, the operation and effects of this exhaust turbocharging 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
opens and closes to select the exhaust gas introduction form. 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 open position (fourth position).
On the other hand, 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 (FIG. 4, the position shown by the chain line). (position shown). Therefore, in the low-speed operating range of the engine where the amount of exhaust gas discharged is small, the exhaust gas is introduced into the turbine casing 21 only from the first exhaust gas passage 27, so that even though the amount of exhaust gas is small, the exhaust gas is The gas flow rate of the exhaust gas in the turbine casing 21 is sufficiently ensured, and the rotation of the turbine wheel is maintained on the high rotation side, making it 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 2.
8 are both effective, so the difference between the exhaust gas pressure at the exhaust inlet side of the turbine casing 21 and the exhaust gas pressure at the scroll section outlet can be made larger (i.e., The expansion ratio of the exhaust gas increases), resulting in a higher level of supercharging performance.

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.

(Effect of the invention) The exhaust turbo supercharging device of the present invention includes a turbine casing having a plurality of exhaust gas inlets separated from each other by partition walls, and an exhaust gas collecting passageway that guides exhaust gas to the plurality of exhaust gas inlets. a common exhaust pipe connected to the turbine casing; and a high-speed exhaust gas inlet provided in the exhaust pipe to additionally introduce exhaust gas on the high-speed side of the engine among the plurality of exhaust gas inlets. In an exhaust turbo supercharging device equipped with a valve device that opens and closes, the valve device has an end face of the high-speed exhaust gas inlet as a valve seat surface, and is oriented toward the upstream side of the exhaust gas with respect to the valve seat surface. The valve body is configured to open when the valve is closed, and in the closed state, the valve body abuts the end face of the high-speed exhaust gas inlet and is located at least near the center of the exhaust gas collecting passage in the partition wall. It is characterized by being constructed so as to cover the entire area located in the exhaust gas flow direction.

Therefore, according to the exhaust turbocharging device of the present invention, at least the end surface facing the exhaust gas flow of the partition wall formed on the turbine casing side and functioning as the valve seat surface of the valve device is near the center of the exhaust gas collecting passage. When the valve device is in the closed state, the entire area of the part with the highest heat load located at Since the abutment from the upstream side prevents exhaust gas from entering between the end face of the partition wall and the valve body, direct contact between the end face of the partition wall and the exhaust gas is almost completely cut off. The temperature rise of the partition wall is smaller than when the end face is directly exposed to exhaust gas throughout the entire operating range of the engine, and this reduces thermal deterioration phenomena such as cracks due to thermal oxidation or thermal stress in the vicinity of the end face of the partition wall. As a result, the durability of the partition wall portion and, by extension, the turbine casing is increased.

In addition, the valve body covers only the part of the end face of the partition wall that has the greatest heat load, that is, the entire area near the center of the exhaust gas collection passage, where there is little influence of heat radiation from the passage wall and a large amount of high-temperature exhaust gas flows. By doing so, it is possible to more effectively prevent thermal deterioration of the partition wall while suppressing the flow resistance of exhaust gas due to the valve body as much as possible, thereby achieving both maintenance of engine performance and durability of the turbine casing. It is possible.

Furthermore, the temperature rise of the partition wall is suppressed by reducing the frequency with which the end face of the partition wall is directly exposed to exhaust gas, so by increasing the thickness of the partition wall and increasing its heat dissipation, Compared to a structure in which the temperature rise of the partition wall is suppressed and thermal deterioration of the partition wall is reduced, the partition wall can be made thinner, and as a result, the turbine casing can be made smaller and lighter. It is something.

[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, FIGS. 8 and 9 are operating state diagrams of the valve device according to other embodiments of the present invention, and FIG. 10 is a conventional exhaust turbo supercharging diagram. FIG. 2 is a structural explanatory diagram of main parts of the 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] a turbine casing having a plurality of exhaust gas inlets separated from each other by partition walls; and a common exhaust pipe connected to the turbine casing and having an exhaust gas collection passage that guides exhaust gas to the plurality of exhaust gas inlets. , an exhaust turbo supercharging device comprising: a valve device that is provided in the exhaust pipe and opens and closes a high-speed exhaust gas inlet that additionally introduces exhaust gas on the high-speed side of the engine among the plurality of exhaust gas inlets; The valve device is provided with a valve body configured to have an end surface of the high-speed exhaust gas inlet as a valve seat surface and to open toward the upstream side of the exhaust gas with respect to the valve seat surface. In the closed state, the valve body contacts the end surface of the high-speed exhaust gas inlet and covers the entire area of at least a portion of the partition wall located near the center of the exhaust gas collecting passage in the exhaust gas flow direction. An exhaust turbo supercharging device characterized by being configured as follows.