JPS6240093Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The present invention relates to a new turbocharger, in particular, a partition plate that is movable back and forth is provided in the scroll portion of the turbine casing to reduce the low speed rotation of an internal combustion engine. The present invention relates to a turbocharger that can improve the low-speed torque and fuel efficiency of an internal combustion engine by increasing its boost pressure using exhaust pulsation.

[Prior Art] In general, a turbocharger rotates a turbine wheel at high speed using exhaust gas from an internal combustion engine, and drives a compressor installed coaxially with the turbine wheel to compress intake air and power the internal combustion engine. It is designed to supercharge to a predetermined pressure.

As shown in FIG. 1, the turbine casing 1 is comprised of a scroll portion 3 surrounding the turbine impeller 2, and an exhaust gas introduction passage portion 4 through which exhaust gas is introduced into the scroll portion 3. The scroll part 3 is set under predetermined conditions so that the exhaust gas introduced therein supplies a uniform operating flow velocity to the turbine wheel 2 along its circumferential side, and its cross-sectional area increases along the circumferential direction. A is formed into a spiral shape that is sequentially reduced.

[Problems to be solved by the invention] By the way, the amount of exhaust gas exhausted from an internal combustion engine increases or decreases according to changes in engine speed.
In particular, when rotating at low speeds, the flow rate of exhaust gas decreases,
Its flow rate also decreases. When the flow velocity of the exhaust gas decreases in this way, there is a problem in that the operating flow velocity for rotationally driving the turbine wheel 2 decreases, making it impossible to increase the supercharging obtained from the compressor to a predetermined pressure.

Further, conventionally, a turbine supercharger is known that utilizes pulsation of exhaust gas in order to increase the rotational speed of the turbine wheel 2 during low-speed rotation. As shown in FIG. 2, the turbine casing 1 includes an exhaust gas introduction passage 4.
A partition wall 5 that divides the scroll portion 3 into two along the flow direction of exhaust gas is provided and is integrally molded with the turbine housing 6 . In this divided turbine casing 1, the exhaust gas exhausted from each cylinder 7 of the internal combustion engine E is collected and connected to two separate exhaust pipes 9 so as not to buffer the pulsations from each other. Ru.

With this configuration, the rotational speed of the turbine wheel 2 can be increased by improving the energy transfer efficiency to the turbine wheel 2 by utilizing the pulsation of the exhaust gas.

However, in such conventional examples,
Since the partition wall 5 is a fixed wall, the internal combustion engine E
This increases the rotation speed of the turbine wheel 2 in the low speed rotation range and also increases the rotation speed in the high speed rotation range, resulting in overcharging in the high speed range and damage due to over rotation of the turbine wheel 2. will occur. For this reason, in this type of turbocharger, it becomes necessary to sacrifice its high speed range to some extent, and the internal combustion engine loses its vigor in the high speed range.

In general, the drawbacks mentioned above are that the rotational speed band of the internal combustion engine (effective rotational speed band) in which the turbocharger can supply a predetermined boost pressure and the rotational speed band of the internal combustion engine that is actually regularly used (practical rotational speed band) This is caused by the fact that the effective rotational speed band is narrower than the practical rotational speed band.

Incidentally, as a related technology, "Turbine case for turbocharger" (Utility Model Application Publication No. 144515/1983) has been proposed, but even with this proposal,
Since the partition plate that divides the nozzle throat into two is fixed, the above problem cannot be solved.

The purpose of the present invention is to take into account the problems of conventional turbochargers and to improve them as much as possible. The purpose of this invention is to provide a reciprocating partition plate in the scroll part of the turbine casing to improve boost pressure by utilizing the pulsation of exhaust gas during low-speed rotation of the internal combustion engine, thereby improving low-speed torque and fuel efficiency. It is an object of the present invention to provide a turbocharger capable of increasing the speed of rotation and widening the effective rotation speed band of the turbocharger without sacrificing the high speed rotation range.

[Means for Solving the Problems] This invention provides a structure in which a part of the scroll part for guiding the exhaust gas that drives the turbine wheel is provided in the scroll part in the low speed rotation region of the engine in the vicinity of the peripheral edge of the turbine wheel. A divided movable partition plate is provided that divides the exhaust gas into two exhaust gas passage chambers along the scroll direction and narrows the exhaust gas outlet to the turbine wheel. a support that is movable relative to each other in the radial direction of the turbine wheels and is engaged so as to form the same plane while preventing mutual movement of the turbine wheels in the axial direction; A member is connected to the upper part of each movable partition plate, and a partition plate control means is provided in the high-speed rotation region of the engine to separate the movable partition plate from the peripheral edge of the turbine impeller through the supporting members. It constitutes a machine and constitutes a means to solve problems.

[Function] The exhaust gas supplied into the scroll section drives the turbine wheel by imparting its energy to the turbine wheel. In the low-speed rotation range of the engine, the partition plate control means moves each movable partition plate close to the peripheral edge of the turbine wheel via each support member to partition the scroll portion into two exhaust gas passage chambers, and Then, the exhaust gas outlet that causes the exhaust gas to collide with the turbine wheel is narrowed down. This increases the flow velocity of the exhaust gas, allowing the turbine wheel to be optimally driven even in this low-speed rotation range. Further, the partition plate control means separates each movable partition plate from the peripheral edge of the turbine wheel via each support member in a high speed rotation range. Then, the exhaust gas outlet that causes the exhaust gas to collide with the turbine wheel is expanded in the low-speed rotation range, so the flow rate of the exhaust gas against the turbine wheel is appropriate for this high-speed rotation range, and over-rotation of the turbine is prevented. .

By the way, since the movable partition plates are engaged with each other so as to form the same plane along the scroll direction, the flow of exhaust gas within the scroll section is not obstructed, and each movable partition plate is connected to the supporting member. The divided surfaces adjacent to each other of the supported movable partition plates are engaged with each other while being allowed to move relative to each other in the radial direction of the turbine wheel, and prevent mutual movement of the turbine wheel in the axial direction. Therefore, even if pressure fluctuations or large exhaust pulsations of exhaust gas passing through the scroll are applied to each movable partition plate, these pressure fluctuations and exhaust pulsations are received by the movable partition plates as a whole. In other words, each movable partition plate has the rigidity to be fixed at a predetermined position in any rotation range. In other words, the structural strength of the partition plate is greatly increased. This improves and maintains the function and durability of the partition plate in a turbocharger that varies the exhaust gas flow rate, so that its reliability can be significantly improved.

[Example] Next, an example of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIGS. 3 and 4, a turbine housing 11 is provided to surround the turbine wheel 2 so that the turbine wheel 2 is rotationally driven by exhaust gas exhausted from the internal combustion engine E. Turbine housing 11
The scroll part 12 surrounds the turbine impeller 2 and the exhaust gas introduction passage part 13 for introducing exhaust gas into the scroll part 12 defines a turbine casing 14. Further, an exhaust gas supply port 15 is formed in the scroll portion 13 of the turbine casing 14 so as to face the peripheral edge of the turbine impeller 2 and supply exhaust gas thereto.

Furthermore, a partition plate 16 is provided inside the scroll portion 12, which is divided into two parts along the longitudinal direction of the scroll portion 12, and is divided along the scroll direction. An exhaust gas passage chamber 18 having 17 is defined. Also,
In the partition plate 16, the dividing surfaces are mutually connected to the turbine blade wheel 2.
The movable partition plate 19 is divided into an appropriate number (in the illustrated example, divided into three) so as to be engaged with each other so as to be relatively movable in the radial direction and to prevent mutual movement of the turbine impeller 2 in the axial direction. 19 and a fixed partition plate 20. Each movable partition plate 19 is formed with a support member 21 extending from the outer peripheral end thereof to the outside of the turbine casing 14 through the turbine housing. This support member 21 supports each movable partition plate 19 and is connected to partition plate control means 22 for reciprocating the movable partition plate 19 in the radial direction.

The partition plate control means 22 includes an operating section 23 and a control section 24.
It consists of The operating portion 23 includes a support member 21 that functions as a piston rod, and a piston 25.
, a casing 27 surrounding these to form the cylinder 26 , a biasing member such as a spring 30 fitted between the casing upper wall 28 and the piston 25 within the casing 27 , and the casing 27 and the casing 27 . Partition wall 3 that partitions turbine casing 14
1 and a pressurized air supply/exhaust pipe 32 provided on the side wall of the casing 27 to supply pressurized air between the piston 25 and the piston 25.

The control section 24 is connected to this pressurized air supply/discharge pipe 32 . The control unit 24 includes an air source 33 such as a master bag, a pressurized air transport pipe 34 that connects the air source 33 and the pressurized air supply/exhaust pipe 32, and a control unit that detects the engine speed of the internal combustion engine and controls the supply/exhaust of pressurized air. It is composed of a unit 35, a supply valve 36 and a discharge valve 37, which are provided in the pressure air transport pipe 34 and supply and discharge pressurized air according to commands from the control unit 35.

When the engine speed of the internal combustion engine E is in a low-speed rotation region below a set rotation speed, the partition plate control means 22, which includes the operating section 23 and the control section 24, moves the movable partition plate 19 to the turbine blade wheel. The moving partition plates 19 are moved close to the turbine wheel 2, and when the rotation speed is in a high speed region exceeding the set rotation speed, the movable partition plates 19 are moved away from the turbine wheel 2.

Further, in order to provide the partition plate 16 in the turbine casing 14, the turbine housing 11 is divided into divided pieces 3 along its longitudinal direction from approximately the center including the casing 27 portion of the partition plate control means 22.
8,39. These divided pieces 38,
A flange 40 is formed on the periphery of 39, and this flange 40 is used for bolts 41 and nuts 4.
2, the turbine housing 11 is integrally formed and defines a turbine casing 14.

On the other hand, each movable partition plate 1 is attached to the flange 40.
A housing groove 43 for the partition plate 19 is formed along the outer peripheral edge of the partition plate 9 to allow movement of the partition plate 19 in the radial direction.

Further, the fixed partition plate 20 extends into the exhaust gas introduction passage section 13 and divides it into two parts, thereby forming an exhaust gas passage chamber 18 formed within the scroll section 12.
A continuous exhaust gas introduction passage chamber 44 is formed therein, and the exhaust gas introduction passage chamber 44 is sandwiched between the flange portions 40 and fixedly supported by being fastened together with bolts and nuts.

Furthermore, the connection portions of the partition plates 16 between the movable partition plates 19 and between the movable partition plates 19 and the fixed partition plates 20 are provided along their joint surfaces 45, as shown in FIG. A continuous partition plate 16 is formed by being connected by the engagement groove 46 and the engagement protrusion 47 that is engaged with the engagement groove 46 .

Therefore, the dividing surface of each movable partition plate 9 along the scroll direction is prevented from moving in the axial direction of the turbine wheel 2 by the engagement groove 46 and the engagement protrusion 47.
and are connected to each other so as to prevent each other and to mutually allow movement of the movable partition plate 19 in the radial direction of the turbine wheel 2.

Therefore, as shown in FIGS. 3 and 4, the turbine casing 14 is connected to the inlet 48 of the exhaust gas introduction passage chamber 44.
From there to the exhaust gas outlet 17 of the exhaust gas passage chamber 18, there are two continuous exhaust gas passages that are divided along the flow direction of the exhaust gas.

Further, the exhaust gas exhausted from the internal combustion engine E is divided and collected into two exhaust pipes 49 to utilize its pulsation. The exhaust gases collected in the respective exhaust pipes 49 are collected in different ignition orders so that the exhaust gases exhausted from the cylinders S of the internal combustion engine E do not buffer each other's pulsations.
For example, the six-cylinder internal combustion engine E in the illustrated example is #1→#5→
In the case of the ignition order of #3 → #6 → #2 → #4,
The #1, #2, and #3 cylinders and the #4, #5, and #6 cylinders are collected and divided into two exhaust pipes 49, respectively.

Therefore, the exhaust gas collected in this way is introduced into the turbine casing 14, passes through two separated exhaust gas passages, and is directed toward the turbine wheel 2 from the exhaust gas outlet 17 while keeping its pulsations alive. It will be squirted out.

Next, the operation of this embodiment will be explained.

As shown in Fig. 3 and Fig. 4, when the engine speed of the internal combustion engine E decreases due to transition from high-speed operation to low-speed operation, or when the engine starts, etc., the engine speed becomes lower than the set rotation speed. When in the region, the partition plate control means 22 functions to bring the movable partition plate 19 close to the turbine wheel 2.

First, the control unit 35 of the control section 24 detects the rotation speed, closes the supply valve 36, and opens the discharge valve 37. Discharge valve 37
When the cylinder 26 is opened, the pressure inside the cylinder 26 is released to the outside, the piston 25 is pushed back by the elastic force of the spring 30, and the movable partition plate 19 is moved to approach the turbine wheel 2. Therefore, the inside of the scroll portion 12 is completely divided into two parts, and the exhaust gas is directly supplied to the turbine wheel 2 through the narrowed exhaust gas outlet 17 of the exhaust gas passage chamber 18 at an increased flow velocity.

Therefore, the exhaust gas flowing through the two exhaust gas passage chambers 18 is divided and ejected from each exhaust gas outlet, and the pulsations of the exhaust gas are not buffered and are supplied to the turbine wheel 2 with high energy pulses. Ru.
As a result, the energy transmission efficiency to the turbine wheel 2 is improved, the rotational speed of the turbine wheel 2 is increased, and the supercharging pressure in the low speed rotation region is increased. At this time, the movable partition plates 19, 19 and the movable partition plate 1
9 and the fixed partition plate 20 are connected as shown in FIG. 5, so that the partition plate 16 has sufficient rigidity even when subjected to large exhaust pressure and exhaust pulsation.

In addition, when the internal combustion engine E transitions from low-speed operation to high-speed operation and the engine speed is in a high-speed rotation region exceeding the set speed, the partition control means 22 functions to move the moving partition 19 away from the turbine wheel 2.

When the engine speed exceeds the set value, the control unit 35 of the control section 24 detects this and
While opening the supply valve 36, the discharge valve 3
Close 7. By opening the supply valve 36, pressure air from the air source 33 is supplied into the cylinder 26. The pressurized air presses the piston 25 and compresses it against the elastic force of the spring 30, and the movable partition plate 19 is moved radially outward and separated from the turbine wheel 2.

When the movable partition plate 19 is separated from the turbine wheel 2 as shown in FIG. 6, the exhaust gas outlet 17 of the exhaust gas passage chamber 18 is also separated, and the exhaust gas flows ejected from the two exhaust gas outlets are mixed. The exhaust gas is ejected to the turbine wheel 2 from the exhaust gas supply port 15 formed by the scroll portion 12 . Further, even at this time, the connection between the movable partition plates 19 and 19 and the connection between the movable partition plate 19 and the fixed partition plate 20 are maintained, so that the rigidity of the partition plate 16 is not lost.

Therefore, the pulsating flow of exhaust gas acts on the turbine wheel 2 as a steady flow having substantially constant energy because the pulsations buffer each other, are attenuated, and canceled out.
Therefore, the energy transmission efficiency to the turbine wheel 2 is reduced, and the turbine wheel 2 is prevented from being over-rotated beyond a predetermined set rotational speed range.

Therefore, in the low-speed rotation range of the internal combustion engine E, where the engine speed is lower than the set rotation speed, the supercharging pressure is increased to improve the low-speed torque and to improve the fuel efficiency as much as possible. Improved. On the other hand, in a high-speed rotation region, damage to the turbine wheel 2 due to over-rotation is prevented.

In this embodiment, the partition plate control means 22 includes one control section 24 and each movable partition plate 1.
In order to smoothly reciprocate the reciprocating movement of the partition plate 9, the actuating portion 23 is provided in parallel with each other along the direction of movement of the actuating portion 9, but the present invention is not limited thereto. The present invention and effects can be achieved by other methods as well.

[Effects of the invention] As described above, the present invention provides the following excellent effects.

(1) The movable partition plates divided along the scroll direction are mutually movable in the radial direction of the turbine wheel, mutually prevent movement of the turbine wheel in the axial direction, and furthermore, these movable partition plates Since the plate is supported by a support member that radially moves through the scroll portion, sufficient rigidity can be ensured over a long period of time against pressure fluctuations and exhaust pulsations that occur within the scroll portion.

(2) It is possible to increase the supercharging pressure in the low-speed rotation region of the internal combustion engine, improve its low-speed torque, and improve fuel efficiency as much as possible.

(3) The turbine wheel will not be over-rotated in the high-speed rotation range of the internal combustion engine, and the turbine wheel will not be damaged.

(4) Compared to conventional turbocharged internal combustion engines, the effective rotational speed band in which the turbocharger is effective can be expanded over both low and high speed rotation regions, and the internal combustion engine can be adapted as much as possible to the practical rotation speed band that is actually commonly used.

[Brief explanation of the drawing]

Fig. 1 is a cross-sectional view showing the turbine casing of a conventional turbocharger, Fig. 2 is a side sectional view showing the turbine casing of a conventional turbocharger having a partition wall, and Fig. 3 is a sectional view showing the turbine casing of a conventional turbocharger. 4 is a side sectional view of FIG. 3, FIG. 5 is a sectional view taken along the line V-V of FIG. 3, and FIG. 6 is a sectional view of FIG. - It is a sectional view taken along the line. In the figure, 2 is a turbine impeller, 12 is a scroll portion, 14 is a turbine casing, 16 is a partition plate, 17 is an exhaust gas outlet, 18 is an exhaust gas passage chamber, 19 is a movable partition plate, 21 is a support member, and 22 is a The partition plate control means and E are internal combustion engines.

Claims (1)

[Scope of utility model registration request] In a scroll portion for guiding exhaust gas that drives a turbine wheel, the inside of the scroll portion is divided into two exhaust gas passage chambers along the scroll direction in the low speed rotation range of the engine, close to the peripheral edge of the turbine wheel. A divided movable partition plate is arranged to narrow the exhaust gas outlet to the turbine wheel, and the adjacent dividing surfaces of each movable partition plate are movable relative to each other in the radial direction of the turbine wheel. A supporting member is connected to the upper part of each movable partition plate, the support member is engaged so as to form the same plane while preventing mutual movement in the axial direction, and is movable in the radial direction of the turbine wheel passing through the scroll portion, A turbo supercharger characterized in that a partition plate control means is provided in a high-speed rotation region of the engine for separating the movable partition plate from the peripheral edge of the turbine impeller via these supporting members.