JP7351769B2 - exhaust turbo supercharger - Google Patents

Description

The present invention relates to an exhaust turbo supercharger installed in an internal combustion engine for an automobile or the like.

In internal combustion engines, exhaust turbo superchargers are used to improve output. This turbocharger generally includes a turbine housing in which turbine blades are arranged and a wastegate valve is built in, a compressor housing in which compressor blades are arranged, and a bearing housing located between the two. . The bearing housing may be integrated into the turbine housing or separate from the turbine housing, but the compressor housing is separate from the bearing housing due to structural constraints. The compressor housing and the bearing housing are fastened together with bolts.

There are several ways to fasten the bearing housing and the turbine housing or the compressor housing. Taking the turbine housing and the compressor housing as an example, they are formed so that their outer peripheries fit together in the axial direction. A pressing plate is superimposed on the exposed portion and fastened with bolts via the pressing plate (clamp plate) (for example, Patent Document 1).

In Patent Document 1, the holding plate is called a mounting plate and has a ring-shaped form, but the holding plate may also be configured in the form of a washer separated into multiple pieces spaced apart in the circumferential direction. By separating the presser plate into multiple pieces in this way, a portion of the presser plate can be fitted into the annular groove formed in one of the housings, making the entire structure more compact while ensuring the necessary presser allowance and maintaining high fastening strength. There are advantages that can be achieved.

On the other hand, the waste gate valve that controls the boost pressure is driven by an actuator, but the actuator is often operated by intake air, and this intake-operated actuator is disclosed in Patent Document 2. It is generally fixed to the compressor housing via a bracket.

Furthermore, as disclosed in Patent Document 2, the movement of the actuator is transmitted to the wastegate valve via a rod. In other words, the support shaft of the wastegate valve is rotatably held in the turbine housing, and by fixing a link to the outward protrusion of the support shaft and connecting the link and rod with a pin, the rod moves forward and backward. It is designed to open and close the waste gate valve.

Japanese Unexamined Patent Publication No. 143326/1983 Japanese Patent Application Publication No. 07-189722

When the compressor housing and the bearing housing are fastened using a plurality of holding plates, in addition to the above-mentioned effects, there is also the advantage that loosening can be prevented by using the elastic deformation of the holding plates to prevent loosening. In a configuration in which the actuator bracket is fixed to the compressor housing while the compressor housing and bearing housing are fixed by a holding plate, there are problems in that there are many fastening points, which makes assembly work time-consuming, and the holding plate and actuator bracket are too close to each other. Because they are arranged in such a way that it becomes difficult to agree on dimensions, etc., there was a problem.

In addition, the movement of the actuator is transmitted to the wastegate valve via the rod, but there is a problem that the positioning of the actuator and wastegate valve tends to be inaccurate due to installation errors between the compressor housing and the bearing housing. Once assembled, the waste gate valve is held in a closed (or open) state and the link and support shaft are welded together, which also makes assembly time-consuming.

The present invention has been made to improve the current situation.

The exhaust turbo supercharger of the present invention is
A turbine housing with a built-in waste gate valve , a compressor housing with a compressor scroll chamber formed therein, a bearing housing located between the turbine housing and the compressor housing, and an actuator to which an actuator operated by intake air is fixed. It is equipped with a bracket for
The compressor housing and the bearing housing are separate bodies, and their outer peripheries are fastened together by pulling together with bolts a plurality of holding plates spaced apart in the circumferential direction.
In the basic configuration,
"A part of the plurality of holding plates is also used as the actuator bracket."
It has the following characteristics.

In this case, the actuator bracket may be fixed with one bolt, or may be fixed with a plurality of bolts as in the embodiment. In other words, the actuator bracket may serve as one holding plate, or one actuator bracket may serve as a plurality of holding plates.

In the present invention, since the actuator bracket also serves as a holding plate, the bolts used to fix the actuator bracket to the compressor housing are no longer necessary. Therefore, it is possible to reduce the number of bolt fastening points for the exhaust turbo supercharger as a whole, thereby reducing the labor involved in assembling the exhaust turbo supercharger. Furthermore, by reducing the number of bolts and retaining plates, costs can be reduced accordingly, and weight reduction can also contribute to improved fuel efficiency.

In addition, since the actuator bracket is in the same state as if it were fixed to the bearing housing, it is possible to prevent errors in the positional relationship between the actuator and wastegate valve from increasing due to assembly errors between the compressor housing and the bearing housing. And the assembly accuracy of the waste gate valve can be improved. This makes it possible to eliminate the conventional welding process between the link and the support shaft.

In particular, if the bearing housing is integrated into the turbine housing as in the embodiment, there will be no assembly error between the bearing housing and the turbine housing, which is preferable because the positioning function between the actuator and the wastegate valve can be improved. It is.

In addition, because the parts where the holding plates overlap are precisely finished by milling, this has the advantage of improving the assembly accuracy of the actuator bracket. It can contribute to improving accuracy.

If the holding plate is separated into multiple pieces, when an external force is applied to the compressor housing and bearing housing to cause them to rotate relative to each other due to vibration, the holding plate will rotate around the axis of the bolt, and the bolt will become loose. Although this may occur, if the actuator bracket is fastened with a plurality of bolts as in the embodiment, the rotation of the actuator bracket is restricted, so there is an advantage that the effect of preventing loosening of the bolts can be improved.

FIG. 2 is a front view of an exhaust turbo supercharger according to an embodiment. FIG. 3 is a rear view of the exhaust turbo supercharger. FIG. 2 is a right side view taken along III-III in FIG. 1; FIG. 2 is a left side view taken along IV-IV in FIG. 1; It is a top view of an exhaust turbo supercharger. (A) is a VIA-VIA view in FIG. 1, and (B) is a BB sectional view in (A). (A) is a VIIA-VIIA sectional view of FIG. 6, and (B) is a diagram of (A) with the bracket and bolt removed. FIG. 7 is a sectional view taken along line VIII-VIII in FIG. 6;

(1).Basic Structure Next, embodiments of the present invention will be described based on the drawings. This embodiment is applied to an exhaust turbo supercharger for an internal combustion engine for an automobile. First, the basic structure will be explained. Regarding the direction in relation to the internal combustion engine, FIG. 1 is a front view, which is viewed from a direction opposite to the intake side of a cylinder head (not shown). Therefore, the direction of the crank axis is the left-right direction, and the width direction of the cylinder head is the front-rear direction.

As can be understood from FIGS. 1 and 2, an exhaust turbo supercharger includes a turbine housing 1 in which turbine blades 2 driven by exhaust gas are disposed, and as can be understood in FIGS. 1 and 3, compressor blades 3 are disposed. The compressor housing 4 includes a compressor housing 4, and a bearing housing 5 located between the compressor housing 4 and the bearing housing 5. The turbine blades 2 are fixed to one end of the rotating shaft 6, and the compressor blades 3 are fixed to the other end of the rotating shaft 6. Therefore, the housings 1, 4, and 5 are arranged in the left-right direction.

As shown in FIG. 2, the turbine housing 1 is formed with an inlet flange 7 that is fixed to a cylinder head or an exhaust manifold (not shown). A gas inlet passage 8 opens rearward. The exhaust gas inlet passage 8 communicates with a turbine-side scroll chamber (not shown) surrounding the turbine blade 2, and the turbine-side scroll chamber communicates with an exhaust gas outlet passage 9 shown in FIG. 3. The exhaust gas outlet passage 9 opens into an outlet side flange 10 facing in the left-right direction.

Therefore, the turbine housing 1 includes a drum-shaped part 1a (see FIG. 1) that surrounds the turbine-side scroll chamber, a cylindrical part 1b (see FIG. 3) in which the exhaust gas inlet passage 8 is formed, a drum-shaped part 1a, and a cylindrical part 1a (see FIG. 3). The side part 1c is provided with a side part 1c projecting from the shaped part 1b to the side opposite to the compressor housing 4, and the side part 1c has a waste gate passage 11 (Fig. 3) is formed. The end of the wastegate passage 11 is opened and closed by a wastegate valve 12.

As shown in FIG. 3, an arm 12a is fixed to the waste gate valve 12, and a longitudinal longitudinal support shaft 13 is fixed to the arm 12a. The support shaft 13 is rotatably held by the side portion 1c of the turbine housing 1, and a link 14 is fixed to an outwardly projecting portion. Further, as shown in FIG. 3, a bearing hole 15 for rotatably holding the support shaft 13 is formed in the side portion 1c of the turbine housing 1.

As shown in FIG. 2, the link 14 is in a vertically longitudinal position, and its upper end is fixed to the support shaft 13, and the tips of the left and right longitudinal rods 16 are connected to the lower end by means of front and rear longitudinal pins 17. Rotatably connected.

The rod 16 is fixed to a valve body (not shown) of an actuator 18 fixed to the compressor housing 4. The actuator 18 is of a type that is operated by the positive pressure intake generated by the exhaust turbo supercharger (it may be a negative pressure operated type), and has a diaphragm type valve body arranged inside a drum-shaped case. , the proximal end of the rod 16 is fixed to the valve body.

The rod 16 can be tilted slightly. Therefore, even if the links 14 are simply connected by the pins 17, the rod 16 can move forward and backward and the links 14 can rotate. The control of the actuator 18 (that is, the opening/closing control of the waste gate valve 12) is performed by an electromagnetic boost pressure control valve (VSV), and the boost pressure control valve is integrated into the actuator 18. has been done.

A compressor scroll chamber 19 (see FIGS. 6 to 8) is formed inside the compressor housing 4, and an intake inlet 20 (see FIG. 2) for supplying intake air to the compressor scroll chamber 19 opens in the axial direction. The intake air pressurized in the compressor scroll chamber 19 is discharged from an intake outlet 21 (for example, FIG. 4) that opens in a direction intersecting the rotation axis. Although only a portion is shown in FIGS. 6(B) to 8, the compressor housing 4 includes an inner plate 22 for forming the compressor scroll chamber 19. Therefore, the compressor housing 4 can be made of aluminum die-casting.

For example, as can be clearly seen from FIG. 3, in this embodiment, the cylindrical portion 1b of the turbine housing 1 extends obliquely upward from the inlet side flange 7, and the turbine scroll chamber and the turbine blades 2 extend from the inlet side flange 7. is also placed on top. Therefore, the exhaust turbo supercharger of this embodiment is of an upward winding type in which the exhaust gas flows upward.

Further, in this embodiment, the turbine housing 1 and the bearing housing 5 are integrated as a cast aluminum product, and the compressor housing 4 is a die-cast aluminum product (or may be a cast product). . Therefore, as shown in FIGS. 1 to 4, a cooling water jacket (not shown) is formed in the turbine housing 1, and a cooling water inlet port 23 is provided at the lower end of the turbine housing 1. A cooling water outlet port 24 is provided at the lower end.

Further, the bearing housing 5 is formed with a bearing portion (not shown) that rotatably holds the rotating shaft 6. Therefore, the bearing housing 5 has an oil inlet 25a (see FIG. 5) that opens upward. At the same time, the oil outlet 25b (see FIGS. 1, 3, and 4(B)) opens downward.

(2). Fastening structure between compressor housing 4 and bearing housing 5, etc. The compressor housing 4 is fixed to the bearing housing 5 at four locations on its outer periphery. Therefore, as shown in FIG. 4, a chevron-shaped projecting portion 26 is formed on the outer circumference of the compressor housing 4 so as to project in all directions. Note that the number of fastening locations between the compressor housing 4 and the bearing housing 5 is not limited to four, but may be fastened at three or four or more locations.

As shown in FIG. 6(B) and FIG. It's sticking out. An annular groove 28 (see also FIG. 1) is formed in a portion of the outer periphery of the bearing housing 5 that is close to the compressor housing 4, and two presser plates 29 whose bases are fitted into the annular groove 28 are used for the actuator. The bearing housing 5 is fastened (clamped) to the compressor housing 4 with four bolts 32 via the bracket 30.

The actuator bracket 30 has an arcuate inner circumference, while an outer circumference has a substantially perpendicular posture, making the actuator bracket 30 L-shaped as a whole. The bearing housing 5 is arranged so as to surround the bearing housing 5 from the outer peripheral side, and the inner peripheral portion thereof enters the annular groove 28 . Furthermore, a rib 30a that protrudes toward the turbine housing 1 is formed on the outer periphery of the actuator bracket 30. Due to the presence of the ribs 30a, the section modulus can be increased and rigidity can be improved.

The actuator 18 has screws (not shown) fixed to the corners of the actuator bracket 30 and to the side opposite to the turbine housing 1, but since the corners are reinforced by ribs 30a, the actuator 18 can be stably held. The actuator bracket 30 has an escape hole 31 through which the rod 16 is inserted.

While the holding plate 29 has only a clamping function, the actuator bracket 30 has both the function of fixing the actuator 18 and the function of fixing the compressor housing 4. That is, the actuator bracket 30 for fixing the actuator 18 also serves as a holding plate that is a fastening means for the compressor housing 4 and the bearing housing 5.

The holding plate 29 is formed into a substantially trapezoidal shape, while the actuator bracket 30 is substantially L-shaped when viewed from the axial direction, as described above. In either case, a nut 33 is held on the surface facing the turbine housing 1 so that it cannot fall off and cannot rotate, and by screwing the bolt 32 into the nut 33, the bearing housing 5 is pressed and fixed to the compressor housing 4. In addition, it is also possible to form a burring part on the actuator bracket 30 and form a female thread therein, without using the nut 33.

As shown in FIG. 7, by separating the annular groove 28 from the compressor housing 4 by a distance E that is smaller than the end surface 4a of the compressor housing 4, there is a distance between the inner surface of the annular groove 28 and the end surface 4a of the compressor housing 4. It forms a step E. Then, as shown in FIGS. 7A and 8, the holding plate 29 and the actuator bracket 30 are elastically deformed, and the bearing housing 5 is elastically pressed against the compressor housing 4. This can prevent loosening. Therefore, the holding plate 29 is preferably manufactured from a leaf spring. Note that the steps are omitted in FIG. 6(B).

As shown in FIGS. 6A and 8, as an example of the positioning means, an inwardly directed engagement protrusion 34 is formed on the inner peripheral surface of the actuator bracket 30, and an annular groove 28 in the bearing housing 5 is formed on the inner peripheral surface of the actuator bracket 30. An engagement recess 35 into which the engagement protrusion 34 is tightly fitted is formed on the inner peripheral surface. Thereby, the actuator bracket 30 and the bearing housing 5 are accurately positioned in the circumferential direction.

(3).Summary In this embodiment, the actuator bracket 30 is also used as a holding plate for fixing the compressor housing 4, which reduces the number of parts and costs, and contributes to improved fuel efficiency through weight reduction. can.

Furthermore, since the end face of the compressor housing 4 is originally finished by milling so that each holding plate 29 can be accurately positioned, the actuator bracket 30 can be placed in an accurate posture and at an accurate position (axial position). is maintained. Therefore, the posture and axial position of the actuator 18 are accurately defined.

Now, since the link 14, the support shaft 13, and the waste gate valve 12 need to move together, they need to be fixed to each other. Specifically, it is necessary to hold the support shaft 13 and the link 14 so that they cannot move relative to each other, and to hold the support shaft 13 and the arm 12a so that they cannot move relative to each other.

In this case, the support shaft 13 is fixed to the arm 12a in advance by welding or the like, and the support shaft 13 is inserted into the bearing hole 15 from the inside of the turbine housing 1, and then the support shaft 13 and the link 14 are moved relative to each other. One method is to fix the support shaft 13 to the link 14 in advance by welding or the like, and then insert the support shaft 13 into the bearing hole 15 from the outside and fit it into the arm 12a. There is a method of holding the two relatively immobile. Conventionally, after the support shaft 13 was fitted into the bearing hole 15 from the inside, the link 14 and the support shaft 13 were fixed by welding.

In contrast, in the present embodiment, the turbine housing 1 and the bearing housing 5 are integrated, and the attitude and axial position of the actuator 18 are accurately defined as described above. Since the positional relationship and posture between the actuator 18 and the waste gate valve 12 are accurately maintained in a predetermined state, for example, when the support shaft 13 is fixed to the arm 12a in advance, the exposure of the support shaft 13 is A square hole is formed in the link 14, and the square hole of the link 14 is fitted into the square part of the support shaft 13, and it is prevented from coming off with a snap ring or nut. It can be easily assembled by doing so.

When the actuator bracket 30 is fastened with two bolts 32 as in this embodiment, rotation of the actuator bracket 30 around the axis of any of the bolts 32 is restricted. Then, when the rotation of the actuator bracket 30 is restricted, relative movement between the compressor housing 4 and the bearing housing 5 is restricted, and as a result, the shaft of the bolt 32 fixing the holding plate 29 thereto is restricted. Rotation around the center is also restricted.

Therefore, the rotation of each holding plate 29 and the actuator bracket 30 is restricted, and loosening of each bolt 32 can be prevented. This point is also one of the advantages of this embodiment.

Although the embodiments of the present invention have been described above, the present invention can be embodied in various other ways. For example, the shape of the actuator bracket can be changed as appropriate depending on the arrangement position of the actuator. It is also possible to adopt a configuration in which bolts are inserted into the bearing housing and the compressor housing is held and held against the bearing housing by a holding plate and an actuator bracket.

The present invention can be embodied in an exhaust turbo supercharger. Therefore, it can be used industrially.

1 Turbine housing 2 Turbine blades 3 Compressor blades 4 Compressor housing 5 Bearing housing 12 Waste gate valve 16 Rod 18 Actuator 26 Compressor housing overhang 28 Annular groove 29 Holding plate 30 Actuator bracket that also serves as holding plate 32 Bolt 33 Nut 34 Engagement Engagement projection 35 Engagement recess

Claims (1)

A turbine housing with a built-in waste gate valve , a compressor housing with a compressor scroll chamber formed therein, a bearing housing located between the turbine housing and the compressor housing, and an actuator to which an actuator operated by intake air is fixed. Equipped with a bracket,
The compressor housing and the bearing housing are separate bodies, and the outer peripheral portions of these are fastened together by drawing together with bolts a plurality of holding plates spaced apart in the circumferential direction,
A part of the plurality of holding plates is also used as the actuator bracket;
Exhaust turbo supercharger.

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