JPS63289217A - Actuator - Google Patents

Abstract

PURPOSE:To optimumly control a turbo-charger at an times by use of an actuator which actuates a passage selector valve for the turbo-charger, by converting the displacement of an operating shaft into a linear or non-linear motion with the use of a cam, and by transmitting the motion to an output shaft for the passage selector valve. CONSTITUTION:A turbo-charger 60 is composed of a compressor section 61 connected to an intake-pipe 61 of an engine 50, a turbine section 62 connected to an exhaust pipe 52 of the engine 50, and a bearing section 63 coupling the former two with each other. Further, the compressor outlet port 67 of the compressor section 61 is connected to the introduction port 8 of an actuator A through an introduction pipe 85. Meanwhile the actustor A has a housing 7 in which the introduction port 8 is formed and in which an operating shaft 6 coupled at one end thereof with a diaphragm 4 is laid. In this arrangement, a rotatable cam 10 is attached to a frame 9 secured to the housing 7. Further, the displacement of the operating shaft 6 is converted into a linear or non-linear motion by means of a cam 10 so as to control the opening degree of a passage selector valve 79.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an actuator, and particularly to an actuator used in a flow path switching type turbocharger.

[Conventional technology]

A turbocharger uses engine exhaust energy to drive a compressor that adjusts the air pressure supplied to the engine to a predetermined value, so it does not reduce the mechanical efficiency of the engine, and is compact and easy to install. Its use in vehicles is increasing because it occupies less space.

The structure of FIG. 8 is shown in US Pat.
No. 9922, etc., and an inlet 8 is provided at one end of the casing 7 through which air at a predetermined pressure to be supplied to the engine is branched and introduced. Further, an insertion hole 7a is formed at the other end of the casing 7, and the operating shaft 6 is attached to the casing 7 with one end freely moving in and out of the insertion hole 7a.

The other end of this actuating shaft 6 is fixed to plate members 5a, 5b, and 5C that are arranged one on top of the other in the housing 7, and the outer edge portion is fixed to the housing 7 by these plate members. The plate surface of the central portion of the flexible diaphragm 4 is clamped.

A spring member 2 is disposed between the plate member 5C located on the side of the insertion hole 7a described above and the inner surface of the other end of the housing 7. This spring member 2 is a plate member 5a.

The diaphragm 4 held between 5b and 5C is biased toward one end of the housing 7 where the inlet 8 is formed.

The housing 7 is divided by the diaphragm 4 into a pressure chamber l on the inlet 8 side and an atmospheric pressure chamber 3 on the insertion hole 7a side.

Although not shown, the inlet 8 is connected to the outlet of the compressor of the turbocharger, and one end of the operating shaft 6 is connected to a flow path switching valve that changes the cross-sectional area of the flow path of the turbocharger.

In this way, when the air pressure at the outlet of the compressor of the turbocharger increases, the pressure in the pressure chamber 1 increases, so the diaphragm 4 moves in the direction of the insertion hole 7a against the biasing force of the spring member 2, and this movement The flow path switching valve connected to one end of the operating shaft 6 is controlled in the opening direction by this.

The spring member 2 described above has a linear characteristic in which the displacement X changes linearly with respect to the applied pressure P, as shown in 20 in FIG. As shown in the cross section of FIG. 9, the spring material 30
In Fig. 7, the wire diameter of 2 is changed in the axial direction.
As shown in Fig. 1, it is possible to use one with non-linear characteristics in which the displacement X changes non-linearly with respect to the applied pressure P.

In Fig. 8, assuming that the spring constant k of the spring member 2 is constant, the spring force F applied to the diaphragm 4 when the spring member 2 is compressed by X from its free length and set is given by the following equation. .

F, to -x, -...-(1
) The force in the direction from the pressure chamber 1 toward the atmospheric pressure chamber 3 along the axis of the operating shaft 6 is positive, and the pressure inside the pressure chamber 1 is P, and the pressure P
The effective area of the diaphragm 4 to which the force is applied is A, and the force F applied to the diaphragm 4.

is given by the following equation.

F, =P-A −・−・(2
) If the displacement of the diaphragm 4 at this time is X, then the following equation can be obtained according to Hooke's law.

-x.
5b, 5c and the actuating shaft 6 move in the direction of the introduction port 8, and the plate member 5b is in a position where it is in contact with the inner surface of the casing 7.

Assuming that this position is the displacement X=O, and the relationship between the applied pressure P and the displacement X is shown, the characteristic straight line 20 shown in FIG. 7 is obtained as described above.

Furthermore, when using a non-linear characteristic spring as shown in FIG. Between the pressure P and the displacement X, there is a curve 21 in FIG.
The relationship shown in is obtained.

-i, when the cross-sectional area of the scroll passage in the turbine casing of the turbocharger is increased, the supercharging pressure with respect to the engine speed becomes a characteristic as shown by curve 90 in the characteristic diagram between them shown in FIG. The torque has a characteristic as shown by curve 91 in FIG. 4, and the torque at low speeds is small and the acceleration response of the boost pressure is insufficient.

Furthermore, if the cross-sectional area of the scroll passage in the turbine casing of the turbocharger is made small, the boost pressure with respect to engine speed will have a characteristic as shown in curve 92 in Figure 4, and the torque with respect to engine speed will have a characteristic as shown in curve 93 in Figure 4. As a result, the torque at low speeds is improved, but at high speeds, the turbine inlet pressure increases abnormally, reducing exhaust efficiency and reducing torque.

On the other hand, in order to reduce the flow loss when the flow path switching valve is fully open, it is necessary to increase the flow path cross-sectional area of the valve seat where the flow path switching valve is installed so that it approaches the flow path cross-sectional area of other parts. It is.

However, if the cross-sectional area of the flow path of the valve seat is increased, the valve opening range that controls the boost pressure from low speed range to high speed range will be narrower, and the flow path switching valve will not be fully open even in the high speed range. , exhaust resistance may occur and cause a decrease in output.

Additionally, if the cross-sectional area of the valve seat is too small compared to the cross-sectional area of other parts, this cross-sectional area of the flow path becomes a restriction, causing flow loss and reducing turbine performance. .

However, if the scroll passage cross-sectional area of the turbine casing or the passage cross-sectional area of the turbine outlet is made smaller in accordance with the passage cross-sectional area of the valve seat, the maximum turbine flow rate decreases and the variable range also becomes narrower.

For these reasons, the cross-sectional area of the flow path of the valve seat to which the flow path switching valve is attached is made as large as possible, and when driving the flow path switching valve, for the same amount of drive, the high speed side of the engine is set to the low speed side of the engine. It is necessary to control the flow path switching valve so that the opening speed of the flow path switching valve is higher than that of the flow path switching valve.

This control is such that the characteristic of displacement X with respect to applied pressure P in FIG. 7 described above is shown by curve 22.
Even if the non-linear characteristic spring described above is used, this characteristic cannot be controlled.

Therefore, in order to obtain the characteristic shown in curve vA22 of FIG. 7, that is, the control characteristic in which the rate of change dx/dp of the displacement X with respect to the applied pressure P increases, pulp was assembled on the operating shaft 6 of FIG. Mechanically controlled actuators and electronically controlled actuators that incorporate electronic circuits to perform desired control have been proposed.

[Problem that the invention seeks to solve]

The above-mentioned mechanically controlled actuator has the disadvantage that it has a large number of parts, has a complicated structure, is large in size, and increases its manufacturing cost.

In addition, the electronically controlled actuator mentioned above cannot be used in a harsh environment where it is placed in the engine room and is exposed to a wide temperature range of -40"C to 200°C and is constantly in a state of vibration. , it may cause variations in characteristics and is not reliable in terms of reliability.

The present invention was made in view of the current state of this type of actuator as described above, and its purpose is to realize a compact structure with a small number of parts, a simple structure, excellent heat resistance and earthquake resistance, and a displacement An object of the present invention is to provide an actuator having a positive rate of change characteristic.

[Means for solving problems]

In order to achieve the above object, the present invention provides an actuator that is driven by the exhaust energy of an engine and changes the cross-sectional area of the flow path by operating a flow path switching valve of a turbocharger that supplies air at a predetermined pressure to the engine. , a casing, an inlet provided at one end of the casing into which air of the predetermined pressure flows, a pressure chamber formed within the casing in continuation with the inlet; an actuating shaft that is attached to the housing so as to be able to move in and out from the other end; and a flexible actuating shaft that has the other end fixed within the housing and that divides the interior of the housing into the pressure chamber and the atmospheric pressure chamber. a diaphragm, a spring member that biases the diaphragm toward the inlet port, a non-linear positioning body movably attached to the housing and connected to one end of the operating shaft, and the non-linear positioning body. Z is configured to have an output shaft that is disposed in pressure contact with the setting body and moves in response to movement of the operating shaft.

[Effect]

In the present invention, when the pressure of the air supplied to the engine increases, the pressure in the pressure chamber increases, so the flexible diaphragm moves against the biasing force of the spring member, and the actuator fixed to this diaphragm moves. One end of the shaft moves in a straight line outside the housing.

As one end of this operating shaft moves, the non-linear position setting body which is rotatably held with respect to the housing moves, so the output shaft that is press-fitted to this non-linear position setting body moves. , moves so as to have a positive rate of change characteristic with respect to the displacement of the operating axis.

For this reason, the flow path switching valve attached to the output shaft is controlled so that the rate of change in opening is greater in the high speed range of the engine than in the low speed range, so that optimal engine characteristics can be obtained. Control takes place.

〔Example〕

Embodiments of the present invention will be described in detail below with reference to FIGS. 1 to 6.

Here, FIG. 1 is a sectional view showing the configuration of an embodiment of the present invention,
Fig. 2 is a sectional view showing the overall configuration when the embodiment of the present invention is applied to a turbocharger, and Fig. 3 shows the engine speed and displacement of the operating shaft of the turbocharger, the opening degree of the flow path switching valve, and supercharging. Figure 4 is a characteristic diagram showing the relationship between turbocharger engine speed, boost pressure and torque, and Figure 5 is a characteristic diagram showing the relationship between turbocharger engine speed, turbocharging pressure and torque, and Figure 5 is a graph showing the relationship between turbocharger engine speed, turbine inlet pressure and shaft output. FIG. 6 is a characteristic diagram showing the relationship between spring strain and spring constant required by the present invention.

As shown in FIG. 1, in the embodiment of the present invention, the insertion hole 7a of the actuator housing 7 already explained using FIG.
A frame 9 is fixed near the frame 9, and a cam 10 as a non-linear position setting body is attached to the frame 9 so as to be rotatable with respect to the housing 7.

The protruding end of the operating shaft 6 from the insertion hole 7a is connected to this cam 10, and the cam 10 is configured to be freely rotatable about the rotation shaft 10a by moving the operating shaft 60 in and out of the insertion hole 7a. It becomes.

A bearing portion 11 is formed at the extended end of the frame 9 described above, and an output shaft 12 is pivotally supported by the bearing portion 11 so as to be freely removable and removable. A flange 12a is formed on this output shaft 12, and a spring 13 is disposed between the plate surface of the extended end of the frame 9 and the flange 12a, and the biasing force of the spring 13 causes one end of the output shaft 12 to move toward the cam 10. is pressed against.

In this way, when the cam 10 rotates due to the movement of the operating shaft 6, the rotation of the cam 10 causes the cam 10 and the output shaft 1 to rotate.
Since the pressure contact position with the output shaft 12 changes on the circumferential surface of the cam 10, the end of the output shaft 12 protruding from the bearing portion 11 is configured to move.

Therefore, by selecting the shape of the cam 10, the moving distance of the protruding end of the output shaft 12 from the bearing portion 11 as the operating shaft 6 moves can be adjusted in the direction in which the operating shaft 6 is pushed by the pressure of the pressure chamber 1. , can be configured to change at a positive rate of change.

As shown in FIG. 2, the actuator having such a configuration is attached to the turbocharger 60 at the inlet 8 portion and the output shaft 12 portion.

That is, the turbocharger 60 has a compressor section 61 connected to the intake pipe 51 of the engine 50, a turbine section 62 connected to the exhaust pipe 52 of the engine 50, and connects the compressor section 61 and the turbine section 62. It is composed of a bearing part 63. In the compressor section 61 , a compressor impeller 65 is disposed within a compressor casing 64 , air is taken in from a compressor inlet 66 , and a compressor outlet 67 is connected to the intake pipe 51 of the engine 50 .

Further, a lead-out pipe 85 is connected and branched to the compressor outlet 67, and the lead-out end of the lead-out pipe 85 is connected to the inlet 8 of the actuator.

On the other hand, in the turbine section 62, a turbine impeller 69 is disposed within the turbine casing 68, and the turbine impeller 69 has a rotating shaft 72 common to the compressor impeller 65, and this rotating shaft 72 is connected to the bearing section 63. It is supported by a bearing 73.

Further, a turbine output lower 1 is formed in the turbine casing 68, and a first scroll chamber 74 and a second scroll chamber 75 are formed in the turbine casing 68, and these first and second scroll chambers 74 and 75 are , and is divided by a partition wall 76, and this partition wall 76 extends halfway into the turbine-entering lower 0.

This turbine-entering lower 0 is connected to the first scroll chamber 7.
4, and a second exhaust gas introduction path 78 connected to the second scroll chamber 75.
is provided so as to be openable in the flow direction of exhaust gas.

Further, a valve seat 82 is held between a flange 80 at the turbine inlet and a flange 81 of the exhaust pipe 52 by bolts, and an opening 82a is formed in the valve seat 82 to set a flow passage cross-sectional area of the valve seat 82. .

One end of the arm body 84 is connected to the valve shaft 83 of the aforementioned flow path switching valve 79, and the other end of the arm body 84 is connected to the end portion of the output shaft 12 projecting from the bearing portion 11.

The operation of the embodiment of the present invention having such a configuration will be described below.

3 to 5, the speed of the engine 50 is N m
In the low speed range from in to N, the pressure at the compressor outlet 67 is low, so the actuator does not operate and the flow path switching valve 79 is closed. At this time, the exhaust gas from the exhaust pipe 52 passes through the first exhaust gas introduction path 77 and passes through the turbine wheel 69.
is discharged from the turbine output lower 1.

In this state, the supercharging pressure changes according to the curve 92 shown in FIG. 4, which corresponds to the case where the cross-sectional area of the scroll passage of the turbine casing is small, so that a highly responsive supercharging pressure characteristic can be obtained. The torque obtained in this case also has a characteristic according to the curve 93 in FIG. 4 in the same manner.

When the speed of the engine 50 exceeds N1, the pressure in the inlet 8 increases and the internal pressure in the pressure chamber 1 becomes greater than the biasing force of the spring member 2, so the operating shaft 6 is pushed in and the cam 10 moves toward the rotation shaft 10a. Start rotating around the center.

When the engine speed is in the range of Ni to N, the displacement of the operating shaft 6 is linearly converted to the output shaft 12 via the cam 10, so as shown in FIG. Engine 5
It increases linearly with an increase in velocity of 0. Further, in this region, as shown in FIG. 5, as the speed of the engine 50 increases, the turbine inlet pressure and shaft output increase linearly.

Furthermore, when the engine speed exceeds N11l, the output shaft 12 is displaced non-linearly as the cam 10 rotates, and the spring constant with respect to spring strain exhibits the characteristics shown in FIG.
The opening degree of the flow path switching valve 79 is controlled in proportion to the positive rate of change in the displacement of the operating shaft 6.

Therefore, as shown by curve 105 in FIG.
The opening degree of is controlled, and the supercharging pressure decreases at engine speeds N, to N□. Similarly, as shown in FIG.
, ~Na a x , the turbine inlet pressure decreases.

In this case, since the exhaust efficiency is improved by reducing the turbine inlet pressure, the shaft output is compared to the conventional case, as shown by curve 108 in FIG. 5, despite the reduction in boost pressure. and increase.

In this way, the engine speed N min ~ N sa
In a wide speed range of X, the turbine inlet pressure and shaft output of the turbocharger can be controlled so as to be maintained in an optimum state.

Further, in the embodiment, by selecting the shape of the cam 10, the opening degree of the flow path switching valve 79 can be easily changed at a desired rate of change with respect to the engine speed.

Furthermore, it has a small number of parts and a simple structure, is compact, has sufficient heat resistance and earthquake resistance to be mounted on a vehicle, and has an extended operating life.

Furthermore, manufacturing costs are significantly reduced, and the actuator can be easily matched to the turbocharger.

〔Effect of the invention〕

According to the present invention, it is possible to control the turbocharger under optimal conditions over a wide range of engine speeds,
Furthermore, by selecting a non-linear position setting body, the desired control can be easily achieved with high precision.

It has a small number of parts, a simple structure, and is compact, reducing manufacturing costs. It also has excellent heat resistance and earthquake resistance, and can withstand the harsh conditions of in-vehicle use.

[Brief explanation of the drawing]

Fig. 1 is a sectional view showing the configuration of an embodiment of the present invention, Fig. 2 is a sectional view showing the overall structure when the embodiment of the invention is applied to a turbocharger, and Fig. 3 is an engine speed of the turbocharger. FIG. 4 is a characteristic diagram showing the relationship between the displacement of the operating shaft, the opening degree of the flow path switching valve, and supercharging pressure, and FIG. 4 is a characteristic diagram showing the relationship between the engine speed of the turbocharger, supercharging pressure, and torque, respectively. Fig. 5 is a characteristic diagram showing the relationship between the engine speed of the turbocharger, the turbine inlet pressure, and the shaft output, respectively;
FIG. 6 is a characteristic diagram showing the relationship between spring strain and spring constant required for the present invention, FIG. 7 is a characteristic diagram showing the relationship between applied pressure and displacement of the spring member, and FIG. FIG. 9 is a cross-sectional view showing the structure of the actuator shown in FIG. ■・-11111 pressure chamber, 2-------spring member,
3--Atmospheric pressure chamber, 4--Diaphragm, 5
a, 5 b, 5 c------ plate member, 6---- operating shaft, 7---- housing, 8-~inlet, 10-----・-Cam, 11-・-
・・Bearing part, 12-・・・・Output shaft, 13・・・・・・・
- Spring, 50... Engine, 51 - Intake pipe, 52 - 11111 Exhaust pipe, 60 - Turbocharger, 61 ------- 1 Compressor section, 62-・
---Turbine part, 63-----One bearing part, 64-
・---Compressor casing, 65...
Compressor impeller, 66... Compressor inlet, 67-- Compressor outlet, 68-1-
---Turbine casing, 69--Turbine wheel, 70--Turbine inlet, 71--
Turbine outlet, 72--Rotating shaft, 73-- Bearing,
74--First scroll chamber, 75--Second scroll chamber,
Crawl room, 76・---・Bulkhead, 77・------・
First exhaust gas introduction passage, 78---Second exhaust gas introduction passage, 79------・Flow path switching valve, 80・------
・Flange, 81--Flange, 82--Valve seat, 82a--Opening, 83--
Valve shaft, 84-- Arm body, 85-- Leading pipe. Figure 1! ...1 Senn2... Booro @ Y O Sai3... Dai Ui Figure 2 Figure 3 Nm1n Nj Nm NmQX
Nj Nmax Fig. 4 Nj Nmax Fig. 5 Nmjn Ni Nm Nma
x Fig. 6 ↑ Spring ρ strain ε Fig. 7 Book j IE sword P (kPa) Fig. 8 No. 9 revised

Claims (1)

[Scope of Claims] 1. An actuator that is driven by exhaust energy of an engine and changes the cross-sectional area of a flow path by operating a flow path switching valve of a turbocharger that supplies air at a predetermined pressure to the engine, the actuator comprising: a housing; an inlet provided at one end of the casing into which air of the predetermined pressure flows; a pressure chamber formed in the casing in succession to the inlet; a flexible diaphragm, the other end of which is fixed within the housing, and which divides the interior of the housing into the pressure chamber and the atmospheric pressure chamber; a spring member biased toward the inlet port; a non-linear positioning body movably attached to the housing and connected to one end of the operating shaft; and pressure-contacted to the non-linear positioning body. An actuator comprising an output shaft that is arranged and moves in response to movement of the actuation shaft. 2. The actuator according to claim 1, wherein the non-linear position setting body is a cam.