JP5192060B2 - compressor - Google Patents

Description

  The present invention relates to a compressor used in a turbocharger.

  Patent Document 1 describes a compressor having a configuration in which guide vanes protrude into the diffuser or retract from the diffuser.

  Non-Patent Document 1 describes a compressor using a plurality of (six) bladed diffusers.

  Non-Patent Document 2 describes a diffuser with a variable vane that can change the opening degree of the air flow path in the diffuser.

Japanese Patent No. 4389442

Journal of the Gas Turbine Society of Japan, vol. 33, no. 4 (20055.7), p. 288-294 “Garrett Electric Boosting Systems Program” Federal Grant DE-FC05-000R22809, U.S. Pat. S. DOE report (2005. 6). p57-58

  However, as in Patent Document 1, Non-Patent Document 1, and Non-Patent Document 2, in a diffuser in which a plurality of blades are arranged in the circumferential direction, the minimum area of the flow path formed between adjacent blades Since the flow rate is limited, it is difficult to suppress a decrease in compressor efficiency when the flow rate is increased from the optimum flow rate.

  Also, when using a diffuser without blades, when the flow rate is reduced from the optimum flow rate, the flow angle from the impeller is small and the flow path becomes longer in the diffuser, increasing the friction loss and increasing the compressor efficiency. It was difficult.

  The present invention has been made to solve the above-described problem, and increases the compressor efficiency when the flow rate of air flowing into the impeller accommodating chamber is small, and suppresses the decrease in the compressor efficiency when the flow rate is large. It aims at obtaining the compressor which can do.

  A compressor according to claim 1 of the present invention is formed along the outer periphery of an impeller housing chamber in which an impeller for accelerating the inflowed air by rotation is communicated with the inside of the impeller housing chamber, and the rotation of the impeller A diffuser chamber that decelerates and pressurizes the air accelerated in step 1 and is formed in a spiral shape outside the diffuser chamber and communicates with the interior of the diffuser chamber to flow the air pressurized in the diffuser chamber to the outside. A scroll chamber and a single blade provided with a linear or curved camber line, or a blade row composed of a plurality of blades arranged in one direction in which air flows, the blade row Of the impeller housing chamber side of the blade disposed on the most upstream side in the air flow direction or the single blade and the impeller An angle θ formed by a line connecting the rotation center position and a line connecting the rotation center position of the impeller and a reference position where the cross-sectional area perpendicular to the direction of air flow in the scroll chamber is maximum is the reference θ. And a diffuser vane that is disposed so as to satisfy 0 ° ≦ θ ≦ 180 ° from the position toward the upstream side, and guides the air flowing in from the impeller accommodating chamber to the scroll chamber.

  According to the above configuration, the diffuser chamber is formed along the outer periphery of the impeller accommodating chamber, and the impeller accommodating chamber and the diffuser chamber communicate with each other so that air can flow. Furthermore, a scroll chamber is formed outside the diffuser chamber, and the diffuser chamber and the scroll chamber communicate with each other so that air can flow. As a result, the air flowing into the impeller accommodating chamber is accelerated by the rotation of the impeller and flows into the diffuser chamber in a state where kinetic energy is applied. And it is pressurized by decelerating in a diffuser chamber, and kinetic energy is converted into pressure energy. The air pressurized in the diffuser chamber is collected in the scroll chamber and flows outside the scroll chamber.

  Here, the diffuser vane is a single blade (single blade) or a cascade composed of a plurality of blades arranged in one direction (acts in the same manner as a single blade), and also accommodates the impeller of the diffuser vane. The tip position on the chamber side is defined. As a result, when air having a flow rate smaller than a preset flow rate flows into the impeller housing chamber, the air flow from the impeller is changed by the diffuser vane of the single blade (or blade row) in the diffuser chamber. Since the pressure is increased by being deflected in the radial direction from the tangential direction, the compressor efficiency on the small flow rate side can be increased as compared with a compressor not provided with a diffuser vane.

  On the other hand, when a flow rate larger than the preset flow rate flows into the impeller housing chamber, the diffuser vane is a single blade and there is no adjacent blade (or the space between the blades is narrow), and there is a throat diameter. Therefore, the air flow does not choke (the choke phenomenon that the air flow is blocked between the wings does not occur). Thereby, compared with the compressor which provided the some diffuser vane along the different direction, respectively, the fall of the compressor efficiency by the side with much flow volume can be suppressed.

  In the compressor according to claim 2 of the present invention, in the plurality of blades constituting the blade row, the distance between the line segment connecting the tip position on the impeller housing chamber side and the rotation center position of the impeller is the one direction The wing on the downstream side is longer than the wing on the upstream side.

  According to the above configuration, in the blade row, the distance between the line segment connecting the tip position on the impeller accommodating chamber side and the rotation center position of the impeller is longer than the blade on the upstream side than the blade on the upstream side. The air flow is deflected and decelerated more in the radial direction than the tangential direction of the impeller. As a result, the pressure increases, and the compressor efficiency on the low flow rate side can be increased.

  In the compressor according to claim 3 of the present invention, the diffuser vane can be protruded and retracted from the diffuser chamber, and moving means for moving the diffuser vane into the diffuser chamber is provided.

  According to the above configuration, as an example, when the flow rate of air flowing into the impeller accommodating chamber is large, the diffuser vane is retracted from the diffuser chamber by the moving means. Thereby, the pressure loss by boundary layer peeling in a diffuser vane can be suppressed, and the fall of compressor efficiency can be suppressed.

  In the compressor according to claim 4 of the present invention, the diffuser vane includes a rotating shaft along a rotating shaft direction of the impeller, and the rotating shaft is rotated to turn a camber line at a front edge portion of the diffuser vane and the impeller. Changing means is provided for changing the angle formed by the tangent to the outer periphery.

  According to the said structure, according to the inflow angle of the air to the diffuser vane which changes with flow volume, a change means rotates the rotating shaft of a diffuser vane, and changes the angle of a diffuser vane (for example, aligns an angle). Thereby, the angle of attack of the front edge portion of the diffuser vane is within an appropriate range, and energy loss due to boundary layer separation or collision at the front edge portion is suppressed, so that a reduction in compressor efficiency can be suppressed.

  Since the present invention is configured as described above, it is possible to increase the compressor efficiency when the flow rate of the air flowing into the impeller housing chamber is small, and to suppress a decrease in the compressor efficiency when the flow rate is large.

1 is an overall view showing a schematic configuration of a turbocharger according to a first embodiment of the present invention. (A) It is explanatory drawing which shows schematic structure of the compressor part which concerns on 1st Embodiment of this invention. (B) It is a fragmentary sectional view of the compressor part concerning a 1st embodiment of the present invention. (A) It is a schematic diagram of the diffuser vane which concerns on 1st Embodiment of this invention. (B) It is a schematic diagram of the other Example of the diffuser vane which concerns on 1st Embodiment of this invention. (A)-(D) It is a schematic diagram of a compressor part when the arrangement position of the diffuser vane which concerns on 1st Embodiment of this invention is changed with 0 degree, 45 degrees, 90 degrees, and 180 degrees. It is a schematic diagram which shows the pressure rise area | region in the compressor housing by the one diffuser vane which concerns on 1st Embodiment of this invention. (A) It is a schematic diagram which shows the pressure distribution in the compressor part without a diffuser vane as a comparative example. (B) It is a schematic diagram which shows the pressure distribution in the compressor part which concerns on 1st Embodiment of this invention. (A) The graph which calculated | required the relationship between the compressor part of 1st Embodiment of this invention and the compressor part of a comparative example (there is no diffuser vane, seven diffuser vanes) and the air flow rate which flows in in a compressor part, and compressor efficiency by calculation It is. (B) It is the graph which measured the relationship between the flow volume of the air which flows in in a compressor part, and compressor efficiency about the compressor part of 1st Embodiment of this invention, and the compressor part without a diffuser vane of a comparative example. It is the graph which calculated | required the relationship between the diffuser vane arrangement | positioning angle and compressor efficiency in the compressor part of 1st Embodiment of this invention, and the compressor part (without a diffuser vane) of a comparative example. (A), (B) It is explanatory drawing which shows the state which made the diffuser vane of the compressor part which concerns on the other 1st Example of 1st Embodiment of this invention protrude in the diffuser chamber, or the state retracted | retracted from the diffuser chamber. . It is explanatory drawing which shows the diffuser vane which can change the angle of the compressor part which concerns on 2nd Example of other 1st Embodiment of this invention. It is explanatory drawing which shows schematic structure of the compressor part which concerns on 2nd Embodiment of this invention. It is a mimetic diagram showing arrangement of a diffuser vane row concerning a 2nd embodiment of the present invention.

  An example of the compressor according to the first embodiment of the present invention will be described.

  FIG. 1 shows a schematic configuration of a turbocharger 10 of the first embodiment. As an example, the turbocharger 10 includes a turbine section 20 provided in an exhaust passage 12 of a car engine (not shown), a compressor section 30 as an example of a compressor provided in an intake passage 14 of the internal combustion engine, and a turbine. And a connecting part 40 that connects the part 20 and the compressor part 30. A rotating shaft 42 is rotatably provided in the connecting portion 40, the turbine 22 is connected to one end side (turbine portion 20 side) of the rotating shaft 42, and the other end side (compressor portion 30) of the rotating shaft 42. The impeller 32 is connected to the side.

  The turbine 22 has a plurality of turbine blades 23, and the turbine blades 23 are erected at predetermined intervals in the circumferential direction on a turbine 22 having a disk shape in plan view. The turbine 22 is rotatably accommodated in the turbine housing 24. The turbine housing 24 includes an exhaust gas inlet 26 into which the high-temperature exhaust gas G1 discharged from the internal combustion engine flows, and an exhaust gas outlet 28 from which the exhaust gas G2 after the work of rotating the turbine 22 in the turbine housing 24 is performed. Have.

  On the other hand, the impeller 32 has a plurality of impeller blades 33, and the impeller blades 33 are erected at predetermined intervals in the circumferential direction on the impeller 32 having a disk shape in plan view. The impeller 32 is rotatably accommodated in the compressor housing 50. The compressor housing 50 has an air inlet portion 34 for taking in atmospheric air A1 and an air outlet 36 from which compressed air A2 compressed by the impeller 32 rotating at high speed is ejected. The compressed air A2 ejected from the air outlet 36 is supplied to the aforementioned engine as combustion supercharged air.

  Here, when the exhaust gas G2 ejected from the exhaust gas inlet 26 collides with the turbine blade 23, the turbine 22 rotates at a high speed, and the impeller 32 connected via the rotating shaft 42 rotates at a high speed. As a result, the air flows into the compressor section 30, and the inflowed air is compressed by the rotation of the impeller 32 and is pumped from the air outlet 36 to the engine.

  As shown in FIG. 2A, the compressor housing 50 includes an impeller housing chamber 52 in which the impeller 32 is housed, and a diffuser chamber that is formed along the outer periphery of the impeller housing chamber 52 and communicates with the inside of the impeller housing chamber 52. 54, a scroll chamber 56 formed outside the diffuser chamber 54 and communicating with the inside of the diffuser chamber 54, and a single (single blade) diffuser vane 38 provided in the diffuser chamber 54. It is configured.

  As shown in FIG. 2B, the impeller accommodating chamber 52 has an opening 58 formed on the side opposite to the rotary shaft 42 in the axial direction of the impeller 32 (hereinafter referred to as arrow Z direction). The part 58 is connected to the air inlet part 34 (see FIG. 1). Thus, air flows from the air inlet portion 34 through the opening 58 into the impeller accommodating chamber 52. Further, the impeller 32 is rotated by the rotation of the turbine 22 (see FIG. 1), and accelerates the air that has flowed into the diffuser chamber 54.

  As shown in FIG. 2A, the diffuser chamber 54 is formed in a substantially annular shape outside the impeller accommodating chamber 52 when viewed in the arrow Z direction. Further, the diffuser chamber 54 has a height in the arrow Z direction lower than the height of the impeller accommodating chamber 52, and the air flowing in from the impeller accommodating chamber 52 in an accelerated state is decelerated and pressurized. Yes. Further, the diffuser chamber 54 has a substantially annular bottom wall 55 when viewed in the arrow Z direction. In the present embodiment, the bottom wall 55 and the diffuser vane 38 are integrally formed, but may be provided separately.

  The scroll chamber 56 is formed in a spiral shape outside the diffuser chamber 54 as viewed in the direction of the arrow Z, and collects air pressurized in the diffuser chamber 54 and flows it to the outside (downstream side). A position near the scroll start point (swirl start position) in the scroll chamber 56 when viewed in the arrow Z direction and the scroll area becomes the maximum area S1 is defined as a point PA (reference position). The scroll area is a cross-sectional area orthogonal to the direction in which air (fluid) flows in the scroll chamber 56.

  As shown in FIG. 3A, the diffuser vane 38 has a contour line L1 that protrudes outward (opposite to the impeller 32) across the straight camber line (center line) M1 when viewed in the arrow Z direction. And a convex outline L2 on the inner side (impeller 32 side). The tip position of the diffuser vane 38 on the impeller 32 side is a point PB, and the rear end position on the side opposite to the impeller 32 side is a point PC.

  Further, the radial direction of the impeller 32 is the arrow X direction, the tangential direction of the impeller 32 is the arrow Y direction, and the angle between the arrow Y direction and the camber line M1 at the front edge (tip side) of the diffuser vane 38 is α. To do. The angle α is set in a range of 0 ° ≦ α ≦ 30 °. Thus, the arrangement of the diffuser vane 38 is determined by determining the angle θ representing the tip position and the angle α representing the arrangement angle. The camber line is obtained by connecting the midpoints of the circles that are inscribed in the outlines L1 and L2.

  Here, in FIG. 2A, the rotation center position of the impeller 32 is the point O, and the angle formed by the line segment connecting the point PA and the point O and the line segment connecting the point O and the point PB is θ. This angle θ is an angle set in the direction from the point PA, which is the reference position, toward the upstream side (the direction opposite to the direction in which air flows and the counterclockwise direction in the drawing). That is, the angle θ represents the tip position of the diffuser vane 38 on the impeller 32 side. 2A shows the arrangement of the diffuser vane 38 when θ = 135 °. As shown in FIGS. 4A, 4B, 4C, and 4D as an example. In addition, the diffuser vane 38 may be arranged so that θ = 0 °, 45 °, 90 °, and 180 °. FIGS. 3A and 3B show the case where θ = 90 °.

  As shown in FIG. 3B, as another example of the diffuser vane 38 (see FIG. 3A) of the present embodiment, a diffuser vane 62 having a curved camber line M2 may be used. The diffuser vane 62 includes a contour line L3 that protrudes outward (opposite side of the impeller 32) across the camber line M2 as viewed in the arrow Z direction, and a contour line L4 that also protrudes outward. Further, the angle between the arrow Y direction and the camber line M2 at the front edge portion (front end side) of the diffuser vane 62 is β. The angle β is also set in the range of 0 ° ≦ β ≦ 30 °.

  Next, the operation of the first embodiment will be described.

  As shown in FIG. 1, in the turbocharger 10, the exhaust gas G <b> 2 ejected at a high speed from the exhaust gas inlet 26 collides with the turbine blade 23, so that the turbine 22 rotates at a high speed and is connected via a rotating shaft 42. The impeller 32 rotates at a high speed.

  Subsequently, as shown in FIG. 2, the air that has flowed into the impeller housing chamber 52 flows into the diffuser chamber 54 while being accelerated by the rotation of the impeller 32, and is pressurized by being decelerated in the diffuser chamber 54 ( Compressed). The air pressurized in the diffuser chamber 54 is collected in the scroll chamber 56 and is pumped from the air outlet 36 to an engine (not shown) outside the compressor housing 50.

  As shown in FIG. 5, in the compressor unit 30, when the impeller 32 rotates in the arrow R direction (clockwise direction in the drawing) and air flows into the diffuser chamber 54 from the impeller accommodating chamber 52, the flow of this air is The diffuser vane 38 is deflected toward the outlet of the scroll chamber 56, and the flow shown by the streamline Qa is shown. As a result of the deceleration of the deflected air flow, the velocity energy is converted into pressure energy in the illustrated area SA, and the pressure at the outlet of the diffuser chamber 54 increases.

  Subsequently, as a result of the air flow decelerating in the area SA, the flow in the area SB connected to the area SA is also decelerated and the pressure rises. As a result of the flow deceleration in the region SA and the region SB, the flow is also decelerated in the region SC in the scroll chamber 56 and the pressure increases. Furthermore, as a result of the flow being decelerated in the region SC, the flow is also decelerated in the region SD upstream of the region SC, and the pressure rises. In this way, the pressure in the compressor unit 30 increases.

  Here, when air having a flow rate smaller than a preset flow rate flows into the impeller accommodating chamber 52, the flow from the impeller 32 flows into one diffuser vane 38 in the diffuser chamber 54 as described above. Thus, since the pressure is increased by being deflected in the radial direction from the tangential direction of the impeller 32, the compressor efficiency on the small flow rate side can be increased as compared with a compressor not provided with the diffuser vane 38.

  In the case of a compressor not provided with a diffuser vane 38 as a comparative example, the streamline becomes a streamline Qb indicated by a broken line, the flow path becomes longer in the diffuser chamber 54, the friction loss increases, and further, it is difficult to decelerate. Therefore, the conversion rate from speed energy to pressure energy decreases, and compressor efficiency decreases.

  FIG. 6A shows a pressure distribution (calculation result) when the impeller 32 rotates in the compressor unit 200 of the comparative example in which the diffuser vane 38 is not provided. FIG. 6B shows a pressure distribution (calculation result) when the impeller 32 rotates in the compressor section 30 of the present embodiment. Note that the magnitudes of the pressures P1, P2, P3, and P4 in the figure are P1 <P2 <P3 <P4, and the larger the area occupied by the pressure P4, the higher the pressure in the compressor section. . In FIG. 6B, the position of the diffuser vane 38 is θ = 90 ° (see FIG. 4C).

  As shown in FIG. 6A, in the compressor unit 200 of the comparative example without the diffuser vane 38, the pressure distribution from the impeller accommodating chamber 52 (inner side) to the scroll chamber 56 (outer side) is the region of the pressure P1, the pressure P2. This is a region of pressure P3, and the maximum pressure is P3.

  On the other hand, as shown in FIG. 6B, in the compressor section 30 of the first embodiment, the pressure distribution from the impeller accommodating chamber 52 (inner side) to the scroll chamber 56 (outer side) is the region of the pressure P2, the pressure P3. The region is a region of pressure P4, and the maximum pressure is P4. Also from this, the compressor section 30 of the present embodiment with one diffuser vane 38 has a higher outlet pressure than the compressor section 200 of the comparative example without the diffuser vane 38, that is, the compressor efficiency is increased. I understand that.

  FIG. 7A shows the case where the single diffuser vane 38 of the first embodiment is provided (graph A) and, as a comparative example, when the diffuser vane 38 is not provided (graph B), the diffuser vane 38 is the diffuser chamber. A relationship (calculation result) between the air flow rate and the compressor efficiency in the case where seven sheets are arranged at equal intervals in the circumferential direction of 54 (graph C) is shown. The compressor efficiency is, for example, a known technique (Japanese Patent Laid-Open No. 2006-009767 (6)) using the temperature and pressure on the inlet side of the compressor unit 30, the temperature and pressure on the outlet side, and the compressor unit 30. And the specific heat ratio of the air flowing into the air. Further, the arrangement of the diffuser vanes 38 of the first embodiment is set to θ = 90 °.

  In FIG. 7A, an air flow rate smaller than a preset air flow rate (not shown) is V1, and an air flow rate larger than the preset air flow rate is V2. Here, when the air flow rate is V1, in the compressor unit 30 (see FIG. 2A) of the first embodiment, the compressor efficiency is K3, and there is no diffuser vane 38 (see FIG. 2A). It is larger than the compressor efficiency K2 of the compressor section. That is, it can be seen that the compressor efficiency on the small flow rate side increases in the compressor section 30 of the first embodiment.

  On the other hand, when the air flow rate is V2, in the compressor unit 30 of the first embodiment, the compressor efficiency is K3, and the diffuser vane 38 (see FIG. 2A) has seven compressors in the compressor unit of the comparative example. The efficiency is greater than K1. That is, in the compressor part 30 of 1st Embodiment, it turns out that the fall of the compressor efficiency in the side with much flow volume is suppressed.

  In the comparative example of the multi-blade configuration in which seven diffuser vanes 38 are provided, the reason why the compressor efficiency is reduced is that the throat area exists between adjacent blades, so the flow chokes when the flow rate increases and the efficiency This is thought to be aggravated. Further, the reason why the compressor efficiency of the compressor unit 30 of the first embodiment is high is that the diffuser vane 38 has a single blade, the throat diameter does not exist, does not choke, and pressure loss due to boundary layer separation of the diffuser vane 38 However, since it is a single wing, it may be less than a multi-wing.

  FIG. 7B shows the air flow rate and the compressor when one diffuser vane 38 according to the first embodiment is provided (graph D) and as a comparative example, when there is no diffuser vane 38 (graph E). The relationship with efficiency (experimental results) is shown. The arrangement of the diffuser vanes 38 of the first embodiment is set to θ = 90 °. Here, from comparison between graph D and graph E, it was found that the difference ΔK in compressor efficiency is about 3 points.

  Next, the optimum range for the arrangement of the diffuser vanes 38 will be described.

  FIG. 8 shows a graph F of a change in compressor efficiency when the arrangement of the diffuser vane 38 (see FIG. 2A) (the angle θ toward the upstream side in the air flow direction) is changed. The graph G represents the average efficiency of the graph F, and the graph H is the compressor efficiency of the comparative example without the diffuser vane 38.

  In FIG. 8, the compressor efficiency of the comparative example remains as low as Ka, whereas the compressor efficiency of the first embodiment is higher than the compressor efficiency Ka of the comparative example even if the angle θ changes (Ka <Kb). <Kc <Kd). Note that the average compressor efficiency of the first embodiment is Kc.

  On the other hand, looking at the graph F of the first embodiment, the average efficiency Kc exceeds the average efficiency Kc in the range of the angle θ from 0 ° to 180 °, and the average efficiency Kc in the range of the angle θ exceeding 180 to 360 °. You can see that it is below. That is, it can be seen that the magnitude of the compressor efficiency varies depending on the angle θ of the arrangement of the diffuser vanes 38, and the angle θ is preferably set in a range of 0 ° ≦ θ ≦ 180 °. In the first embodiment, the compressor efficiency reaches the maximum value (Kd) when θ = 90 °.

  Next, another example of the compressor unit 30 according to the first embodiment will be described.

  The diffuser vane 38 of the first embodiment is not only fixed integrally with the bottom wall 55 of the diffuser chamber 54 but also protrudes or diffuses into the diffuser chamber 54 as shown in FIGS. 9 (A) and 9 (B). You may comprise so that it may evacuate from the inside of the chamber 54.

  As shown in FIG. 9A, a compressor unit 70, which is another first example of the compressor unit 30 of the first embodiment, includes a compressor housing 74 in which a diffuser vane 72 is movably provided, and a diffuser vane 72. And an eccentric cam 76 as an example of a moving means for moving the. The compressor housing 74 has the same configuration as that of the compressor housing 50 (see FIG. 1) except for a portion where the diffuser vane 72 is moved, and includes an impeller accommodating chamber 52, a diffuser chamber 54, and a scroll chamber 56. Yes.

  The diffuser vane 72 has the same size and shape as the above-described diffuser vane 38 (see FIG. 2A) at the portion protruding into the diffuser chamber 54. Further, the eccentric cam 76 is swung in the arrow + R direction (clockwise direction in the figure) by a motor (not shown) so that the diffuser vane 72 protrudes into the diffuser chamber 54. Furthermore, one end of a tension spring 78 is attached to the surface of the diffuser vane 72 on the side of the eccentric cam 76 to apply a return force. Accordingly, when the eccentric cam 76 is swung in the arrow -R direction (the counterclockwise direction in the drawing) by the motor, the diffuser vane 72 is retracted from the diffuser chamber 54 to the outside.

  Here, when the air flow rate flowing into the compressor unit 70 is larger than, for example, the air flow rate V3 shown in FIG. 7A, the eccentric cam 76 is operated as shown in FIG. 72 is retracted from the diffuser chamber 54. As a result, there is no diffuser vane in the diffuser chamber 54, so the graph of the compressor efficiency is not the graph A for the single vane diffuser vane 38 in FIG. That is, in FIG. 9B, pressure loss due to boundary layer separation in the diffuser vane 38 is eliminated, so that a reduction in compressor efficiency can be suppressed.

  In addition, as a method of obtaining the data of the air flow rate flowing into the compressor unit 70, for example, a data table of the air flow rate corresponding to the engine speed and the accelerator opening is set in advance, and the obtained engine speed is obtained. The air flow rate may be determined based on the accelerator opening. In addition to indirectly obtaining the flow rate data as described above, a flow rate sensor may be provided in the intake passage 14 (see FIG. 1) to directly obtain the flow rate data.

  On the other hand, the diffuser vane 38 may be provided not only in the diffuser chamber 54 but also in an installation angle changeable in the diffuser chamber 54.

  As shown in FIG. 10, a compressor unit 80, which is another second example of the compressor unit 30 of the first embodiment, is replaced with a diffuser vane 38 in the above-described compressor unit 30 (see FIG. 2A). The diffuser vane 82 is provided. The diffuser vane 82 is basically the same size as the diffuser vane 38 except that a rotation shaft 84 having an axial direction parallel to the rotation axis direction (arrow Z direction) of the impeller 32 is provided. . The rotating shaft 84 is rotated (turned) by an angle changing unit 86 as an example of changing means configured to include a motor and a link mechanism (not shown), and the angle α described above (see FIG. 3A). It can be changed.

  Here, in the compressor unit 80, if the flow rate of the air flowing in is different, the flow angle to the front edge of the diffuser vane 82 changes. However, the relationship between the flow rate and the flow angle is set in advance and flows in. By obtaining the air flow rate by the above-described method (engine speed, accelerator opening, flow rate measurement), the angle changing unit 86 can obtain the data of the inflow angle. Then, the angle changing unit 86 changes the angle α of the diffuser vane 82 within the range of 0 ° ≦ α ≦ 30 ° with respect to the inflow angle, thereby suppressing energy loss due to boundary layer separation or collision at the leading edge. Therefore, it is possible to suppress a decrease in compressor efficiency.

  Next, an example of a compressor according to the second embodiment of the present invention will be described. Note that members that are basically the same as those in the first embodiment described above may be given the same reference numerals as those in the first embodiment, and description thereof may be omitted.

  FIG. 11 shows a compressor unit 90 as an example of the compressor of the second embodiment. The compressor unit 90 is provided with a diffuser vane row 92 as an example of a blade row instead of the single blade diffuser vane 38 in the compressor unit 30 (see FIG. 2A) of the first embodiment. The impeller 32, the impeller accommodating chamber 52, the diffuser chamber 54, and the scroll chamber 56 are configured.

  As shown in FIG. 12, the diffuser vane row 92 includes a first diffuser vane 92 </ b> A as an example of an upstream wing arranged along one direction in which air flows (arrow T direction in the drawing), and a downstream wing. And a second diffuser vane 92B as an example. As an example, the first diffuser vane 92A and the second diffuser vane 92B have the same shape (the same camber line shape) and the same size, and the first diffuser vane 92A has the impeller 32 (see FIG. 2A). In the direction of arrow R, which is the rotational direction, the entirety is disposed upstream of the second diffuser vane 92B. Further, the rear end portion of the first diffuser vane 92A and the front end portion of the second diffuser vane 92B are arranged so as to overlap each other when viewed from the direction of the arrow W perpendicular to the direction of the arrow T.

  Here, the tip position of the first diffuser vane 92A on the impeller 32 side (upstream side in the arrow T direction) is a point PD, and the rear end position on the opposite side (downstream side in the arrow T direction) of the impeller 32 is a point PE. To do. The upstream end position of the second diffuser vane 92B in the arrow T direction is a point PF, and the downstream rear end position is a point PG. Note that the arrow T direction is, for example, a direction passing from the diffuser chamber 54 toward the scroll chamber 56 (outside) through the points PD and PG. In FIG. 12, the impeller 32 (see FIG. 2A) is not shown, and only a part of the compressor housing 50 is shown by a two-dot chain line.

  In the compressor unit 90, as an example, an angle θA (an angle from the point PA to the upstream side) formed by a line segment having a distance R0 connecting the point PA and the point O and a line segment having a distance R1 connecting the point O and the point PD. Is set to θA = 135 °. Further, an angle θB (an angle from the point PA to the upstream side) formed by a line segment of the distance R0 connecting the point PA and the point O and a line segment of the distance R2 connecting the point O and the point PF is θB = 112. It is set to 5 ° (that is, θA> θB). The distance R2 of the second diffuser vane 92B on the downstream side in the arrow T direction is longer than the distance R1 of the first diffuser vane 92A on the upstream side.

  Further, in the compressor section 90, a line parallel to the line segment connecting the point PA and the point O and passing through the point PD is N1, and a camber line (not shown) on the tip side (point PD side) of the first diffuser vane 92A The angle formed with the line N1 is θa. Similarly, a line parallel to the line segment connecting the point PA and the point O and passing through the point PF is N2, and a camber line (not shown) on the tip side (point PF side) of the second diffuser vane 92B is connected to the line N2. The angle formed is θb. Here, the first diffuser vane 92A and the second diffuser vane 92B are arranged so that θa> θb with respect to the angles θa and θb.

  On the other hand, a gap 94 is formed between the rear end portion (point PE side) of the first diffuser vane 92A and the front end portion (point PF side) of the second diffuser vane 92B. The size of the gap 94 is set in advance by experiments so that the first diffuser vane 92A and the second diffuser vane 92B allow air to flow in the same manner as a single (single blade) diffuser vane.

  Next, the operation of the second embodiment will be described.

  As shown in FIG. 11, in the compressor unit 90, when the impeller 32 rotates in the arrow R direction and air flows into the diffuser chamber 54 from the impeller accommodating chamber 52, this air flow is scrolled by the diffuser vane row 92. It is deflected in the direction of the outlet of the chamber 56, resulting in the flow indicated by the streamline Qc shown in the figure. As a result of the air flow being decelerated by the deflection, the velocity energy is converted into pressure energy, the pressure at the outlet of the diffuser chamber 54 is increased, and the pressure in the compressor unit 90 is increased.

  Here, in the diffuser vane row 92, the first diffuser vane 92A and the first diffuser vane 92A arranged in the direction of the arrow T (see FIG. 12) are defined. The second diffuser vane 92B acts in the same manner as the single blade and flows air. Accordingly, when air having a flow rate smaller than a preset flow rate flows into the impeller housing chamber 52, the air flow from the impeller 32 is tangent to the impeller 32 in the diffuser vane row 92 in the diffuser chamber 54. It is deflected in the radial direction from the direction and decelerated, and the pressure at the outlet of the diffuser chamber 54 increases. For this reason, in the compressor part 90, compared with the compressor which does not provide the diffuser vane row | line | column 92 or the single vane diffuser vane, the compressor efficiency of the small flow volume side can be raised.

  On the other hand, when air having a flow rate higher than a preset flow rate flows into the impeller accommodating chamber 52, in the diffuser vane row 92, the interval between the first diffuser vane 92A and the second diffuser vane 92B is narrow, and the diffuser vane. Since there is no other diffuser vane adjacent to the row 92, there is no throat diameter and the air flow does not choke (the choke phenomenon that clogs the air flow does not occur). Thereby, in the compressor part 90, the fall of the compressor efficiency by the side with much flow volume can be suppressed compared with the compressor which provided the some diffuser vane along the different direction, respectively.

  Further, as shown in FIGS. 11 and 12, in the first diffuser vane 92A and the second diffuser vane 92B of the compressor section 90, the tip position (point PD, point PF) on the impeller accommodating chamber 52 side and the rotation center of the impeller 32 The distance between the line connecting the position (point O) is longer in the second diffuser vane 92B (distance R2) on the downstream side than in the first diffuser vane 92A (distance R1) on the upstream side. This flow is deflected more in the radial direction with respect to the tangential direction of the impeller 32 and decelerated. As a result, the pressure at the outlet of the diffuser chamber 54 increases, so that the compressor efficiency on the small flow rate side can be further increased.

  Here, by setting the shape, size, and clearance 94 of the first diffuser vane 92A and the second diffuser vane 92B so that the diffuser vane row 92 acts as a single blade, the diffuser vane 38 ( It has been found that the same results (actions) as those shown in FIGS. 6 to 8 can be obtained using FIG. That is, the arrangement of the diffuser vane row 92 is set within the range of the angle θ similar to the arrangement of the single vane diffuser vane 38 shown in FIGS. 4A to 4D, thereby flowing into the impeller accommodating chamber 52. This has the effect of increasing the compressor efficiency when the air flow rate is low and suppressing the reduction of the compressor efficiency when the air flow rate is high.

  In addition, this invention is not limited to said embodiment.

  The diffuser vane row 92 is not limited to the blade row composed of two blades (the first diffuser vane 92A and the second diffuser vane 92B) as long as it acts as a single blade, but is composed of three or more blades. It is good. Further, the diffuser vane row 92 may be configured to be moved in and out of the diffuser chamber 54 by moving means such as the eccentric cam 76 shown in FIGS. 9 (A) and 9 (B). Furthermore, the arrangement angle of the first diffuser vane 92A and the second diffuser vane 92B may be changed using the angle changing unit 86 shown in FIG.

30 Compressor (an example of a compressor)
32 impeller 38 diffuser vane 52 impeller accommodating chamber 54 diffuser chamber 56 scroll chamber 70 compressor section 72 diffuser vane 76 eccentric cam (an example of moving means)
80 Compressor part 82 Diffuser vane 84 Rotating shaft 86 Angle changing part (an example of changing means)
90 Compressor (example of compressor)
92 Diffuser vane row (example of blade row)
92A 1st diffuser vane (an example of a wing)
92B 2nd diffuser vane (an example of a wing)
M1 Camber line

Claims (4)

Formed along the outer periphery of the impeller housing chamber in which the impeller for accelerating the inflowed air by rotation is accommodated and communicated with the inside of the impeller housing chamber, and the air accelerated by the rotation of the impeller is decelerated and pressurized. A diffuser chamber,
A scroll chamber that is spirally formed on the outside of the diffuser chamber and communicates with the interior of the diffuser chamber, and flows air pressurized in the diffuser chamber to the outside;
A single wing provided with a linear or curved camber line or a wing row composed of a plurality of wings arranged along one direction in which air flows is provided in the diffuser chamber. A line segment connecting the tip position on the impeller housing chamber side of the blade or the single blade disposed on the most upstream side in the flow direction and the rotation center position of the impeller, the rotation center position of the impeller, and the air in the scroll chamber The angle θ formed by the line segment connecting the reference position where the cross-sectional area orthogonal to the flow direction of the maximum is 0 ° ≦ θ ≦ 180 ° from the reference position toward the upstream side, A diffuser vane for guiding the air flowing in from the impeller chamber to the scroll chamber;
Having a compressor.   In the plurality of blades constituting the blade row, the distance between the line segment connecting the tip position on the impeller-accommodating chamber side and the rotation center position of the impeller is higher in the blade on the downstream side in the one direction. The compressor according to claim 1, wherein the compressor is longer than the blades on the side.   3. The compressor according to claim 1, wherein the diffuser vane can be protruded and retracted from the diffuser chamber, and moving means for moving the diffuser vane into the diffuser chamber is provided. The diffuser vane includes a rotation axis along a rotation axis direction of the impeller,
3. The compressor according to claim 1, further comprising a changing unit that rotates an axis of rotation to change an angle formed by a camber line at a front edge portion of the diffuser vane and a tangent line on the outer periphery of the impeller.

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