JPH04111528U - Variable displacement supercharger - Google Patents

Abstract

(57) [Abstract] [Purpose] The present invention relates to a variable displacement supercharger equipped with a variable scroll wall that can vary the area of the nozzle throat. By making the width variable, the purpose is to ensure the flow velocity of exhaust gas and keep the outflow angle constant so as not to impair turbine efficiency. [Structure] In a variable capacity supercharger equipped with a variable scroll wall 5 that can vary the area of the nozzle throat section 3, a turbine rotor inlet width that makes the turbine rotor inlet width variable according to the area of the nozzle throat section 3. Variable mechanism 1
1.

Description

[Detailed explanation of the idea]

0001

[Industrial application field]

This invention relates to a supercharger attached to an engine, and in particular, the area of the nozzle throat section is The present invention relates to a variable displacement supercharger equipped with a variable scroll wall that can vary the amount of water.

0002

[Conventional technology]

Traditionally, it has been used as a supercharger for engines installed in automobiles, etc. to convert exhaust energy into The turbine is driven by the turbine, and the turbocharger is driven by the turbine. A so-called turbocharger device is used, which combines a compressor that performs ing.

0003 In addition, such superchargers are controlled by adjusting the exhaust gas inflow speed and exhaust pressure into the engine. A variable boost pressure adjustment mechanism is provided to adjust the boost pressure according to the rotational state of the engine.

0004 An example of this is shown in FIG. 7, for example. That is, the turbine how Inside the engine 1, the inner end is pivotally supported by a pivot 2, and the outer end is connected to a turbine. A floating end 4 is formed at the inlet portion of the housing 1, that is, the nozzle throat portion 3. A variable scroll wall (spring belt) 5 is provided, and this variable scroll wall (spring belt) The free end 4 of the wall 5 is connected to the turbine by an actuator 6 via its operating rod 6'. of the nozzle throat section 3 by moving it in the circumferential direction (in the direction of arrows a and b). The supercharging pressure to the turbine rotor 7 is adjusted by adjusting the area Ath. There is.

[0005]

[Problem that the idea aims to solve]

However, as mentioned above, it is difficult to change the flow path area of the nozzle throat from the circumferential direction. However, the flow velocity and outflow angle of the exhaust gas flowing into the turbine rotor inlet are not necessarily determined by not suitable for the turbine rotor, which effectively blocks the exhaust energy. There is a problem that the information is not transmitted to the data.

[0006] This invention was devised in view of these issues, and it reduces the area of the nozzle throat. By making the turbine rotor inlet width variable according to the variation of the Variable displacement type that maintains a constant flow angle and maintains a constant flow angle so as not to impair turbine efficiency. The purpose is to provide superchargers.

[0007]

[Means to solve the problem]

For this reason, the variable displacement supercharger of this invention has a variable nozzle throat area. In a variable capacity supercharger equipped with a variable scroll wall, the nozzle slot Turbine rotor inlet width that changes the width of the turbine rotor inlet depending on the area of the It is characterized by being constructed with a variable mechanism.

[0008]

[Effect]

In the above-mentioned variable capacity supercharger of the present invention, the area of the nozzle throat section is adjusted by a variable screen. This can be varied by moving the wall, and depending on this variation, the tar The exhaust flow to the turbine rotor can be adjusted by changing the inlet width to the bin rotor using a variable inlet width mechanism. This ensures speed and keeps the outflow angle the same.

[0009]

【Example】

Hereinafter, embodiments of the present invention will be explained with reference to the drawings. This shows a variable capacity supercharger as an example. Figure 1 shows this supercharger as a turbine. Cross-sectional views taken at an angle perpendicular to the rotor axis, Figures 2 and 3 show the operating state. In order to explain the situation, a cross section of the turbine rotor inlet section taken at an angle perpendicular to Figure 1 is shown. A top view, FIG. 4 shows the relationship between the turbine scroll area and the variable scroll wall circumferential angle. The graph shown in Figure 5 is a graph showing the relationship between the turbine rotor inlet width and the nozzle throat area. Figure 6 is a diagram of the turbine housing to explain the outflow angle of the supercharger. This is a schematic diagram, and in FIGS. 1 to 6, the same symbols as in FIG. 7 indicate almost the same parts. There is.

0010 Now, in Figures 1 to 3, 1 is a turbine housing, 2 is a variable scroll wall. 5 is the rotation axis, 3 is the nozzle throat part of the turbine housing 1, 4 is the variable scroll 6 is the actuator, 7 is the turbine rotor, and 8 is the turbine rotor. This is the inlet of the exhaust gas to the tank 7, and its configuration is similar to that of the conventional one described above (see Fig. 7). ) is almost the same as

[0011] The turbine rotor inlet 8 is provided with a direction perpendicular to the circumferential direction of the turbine ( A movable ring 9 is provided which can be pushed in and out in the direction of arrows c and d. The movable ring 9 is actuated by another actuator 10 via the actuating rod 10', - An inlet width variable mechanism 11 capable of adjusting the width L of the inlet portion 8 to the bin rotor 7 is configured. ing.

0012 That is, the variable scroll wall 5 is moved as shown in FIG. 3 as the reduced area Ath', the inlet width can be changed accordingly. The mechanism 11 pushes in the movable ring 9 to reduce the width of the turbine rotor inlet section 8. The width is L' (see FIG. 5).

[0013] Also, as shown in FIG. 2, let the nozzle throat portion 3 have an enlarged area Ath. In response to this, the variable inlet width mechanism 11 moves the movable ring 9 backward. The width of the turbine rotor inlet portion 8 is expanded to the width L (Fig. 5). reference).

[0014] These operations are controlled by an actuator using a computer (not shown). This is achieved by actuating the actuator 10 in conjunction with the operation of 6.

[0015] Note that the movable ring 9 may be one continuous ring, or may be a plurality of divided bodies connected together. They may be formed in contact with each other.

[0016] Next, to explain the outflow angle of the turbine scroll, this The exit angle from the turbine determines the turbine rotor inlet velocity triangle; This is an important parameter because it is closely related to the bin efficiency.

[0017] Now, as a first approximation, we will explain the density change of the gas at the turbine scroll inlet and outlet. If we assume that there is no change, the relationship will be based only on simple geometric dimensions.

According to FIG. 6, from the equation of continuity between the turbine scroll inlet nozzle area and the annular outlet, ρ ₀ c ₀ Ath=ρ ₁ c ₁ πd ₁ L sin α (1) Also, from the free vortex condition, c ₀ r ₀ cosα ₀ =c ₁ (d ₁ /2)cosα...(2) From equations (1) and (2), tanα = (1/2π)(ρ ₀ /ρ ₁ )(Ath/Lr ₀ cosα ₀ )...(3) Here, as the first approximation, (ρ ₀ /ρ ₁ )≒1 and since α ₀ ≒1, tanα=(1/2π)(Ath/Lr ₀ )・・(4) ∴α=tan ^-1 (1/2π)(Ath/Lr ₀ )...(5) It becomes.

Therefore, it can be seen that the outflow angle from the scroll (the angle at which the exhaust gas hits the turbine rotor) α is determined by (Ath/Lr ₀ ).

Note that the symbols in the above formula are explained as follows. ρ ₀ , ρ ₁ : Gas density at scroll inlet and outlet c ₀ , c ₁ : Absolute velocity at scroll inlet and outlet d ₁ : Scroll outlet diameter (r ₁ = d ₁ /2) L: Scroll outlet width Ath: Nozzle throat Partial area r ₀ : Distance from the center of the supercharger to the center of Ath α : Outflow angle of gas from the scroll α ₀ : Scroll inlet inclination angle

[0021] Furthermore, the relationship between the scroll wall circumference angle θ and the turbine scroll area is shown in Fig. 4. It becomes like this. That is, by winding up the variable scroll wall 5, the nozzle The area of the throat portion 3 is reduced from Ath to Ath'.

Therefore, in the present invention, in order to always keep the outflow angle α determined by (Ath/Lr ₀ ) constant, as shown in FIG. )min, the turbine inlet width is varied from Lmax to Lmin.

[0023] As mentioned above, such operations involve inserting and retracting the movable ring 9. Therefore, it is done.

The present invention provides a turbocharger in which the turbine capacity can be varied by varying the variable scroll wall as described above, and the turbine rotor inlet width is adjusted according to the change in the nozzle slot area by (Ath/Lr ₀ )=( By controlling the exhaust gas to satisfy the condition that Ath'/L'r ₀ )=constant, it is possible to ensure the exhaust flow velocity to the turbine rotor and to keep the outflow angle the same at all times, thereby increasing the turbine efficiency. It is something that can be prevented from being damaged.

[0025]

[Effect of the idea]

As detailed above, according to the variable displacement supercharger of the present invention, the nozzle throat section In a variable capacity supercharger equipped with a variable scroll wall that can vary the area of the The turbine rotor inlet width can be varied according to the area of the nozzle throat. By having a variable rotor inlet width mechanism, the nozzle throat area can be expanded or reduced. Expand or shorten the turbine rotor inlet width depending on the This ensures the flow velocity of the exhaust gas to the turbine rotor and also maintains the outflow angle at all times. As a result, efficiency decreases as the turbocharger capacity changes. This has the effect of keeping the performance of the supercharger stable at all times.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a variable displacement supercharger according to an embodiment of the present invention.

FIG. 2 is a sectional view of a turbine rotor inlet of a variable displacement supercharger according to an embodiment of the present invention.

FIG. 3 is a sectional view of a turbine rotor inlet of a variable displacement supercharger according to an embodiment of the present invention.

FIG. 4 is a graph showing the relationship between the variable scroll wall circumference angle and the turbine scroll area in the present supercharger.

FIG. 5 is a graph showing the relationship between the nozzle throat area and the turbine rotor inlet width in the present supercharger.

FIG. 6 is a schematic diagram of a turbine housing for explaining an outflow angle in a variable supercharger.

FIG. 7 is a sectional view of a conventional variable displacement supercharger.

[Explanation of symbols]

1 Turbine housing 2 Pivot 3 Nozzle throat section 4 Floating end 5 Variable scroll wall 6,10 actuator 6', 10' operating rod 7 Turbine rotor 8 Turbine rotor inlet 9 Movable ring 11 Turbine rotor inlet width variable mechanism Ath, Ath' Nozzle throat area L, L' Turbine rotor inlet width

Claims (1)

[Scope of utility model registration request] 1. In a variable capacity supercharger equipped with a variable scroll wall that can vary the area of a nozzle throat section, a turbine rotor inlet width that makes the turbine rotor inlet width variable according to the area of the nozzle throat section. A variable capacity supercharger characterized by being configured with a variable mechanism.