DIAPHRAGM ACTUATOR

Abstract

Actuator of the membrane type, which drives an actuating rod (51) in an axial direction of the actuating rod (51), with: a membrane (53) which is connected to the actuating rod (51); a low-pressure chamber (54) adjacent to an end face of the membrane (53) in the axial direction; a high-pressure chamber (55) which is adjacent to the other end of the membrane (53) in the axial direction; a return spring (56) which is provided in the low-pressure chamber (54) and pushes the diaphragm (53) towards the high-pressure chamber (55); a holder (62) which is provided on a surface near the high-pressure chamber (55) in the membrane (53); and an elastic element (66, 69, 70) which is arranged between the holder (62) and a wall surface which faces the holder (62) in the axial direction inside the high-pressure chamber (55), wherein the actuating rod (51) extends from the diaphragm (53) to the high-pressure chamber (55) and penetrates a wall body (59b) which faces the holder of the high-pressure chamber (55) in the axial direction, wherein a bearing section (63) which holds the actuating rod (51) is supported by the wall body (59b), wherein the bearing section (63) projects from the wall body (59b) into the high-pressure chamber (55), wherein the elastic element (66, 69, 70) is attached to a surface (65b) which is near the holder (62) in the bearing section (63), and wherein the holder (62) is constructed in such a way that it comes into contact with the elastic element (66, 69, 70) when the membrane (53) moves towards the high pressure chamber (55) to a maximum.

Description

Technical field

[0001] The present invention relates to a membrane-type actuator. Background of the state of the art

[0002] Traditionally, for example, a diaphragm-type actuator is used to open and close the valve body of a so-called wastegate valve in a turbocharger of an internal combustion engine (see, for example, patent document 1). The diaphragm-type actuator has an actuating rod connected to a valve body, a diaphragm that drives the actuating rod, a low-pressure chamber and a high-pressure chamber adjacent to each other, with the diaphragm positioned between them in the axial direction of the actuating rod, and a return spring located inside the low-pressure chamber that pushes the diaphragm. List of the state of the art Patent document Patent document 1: Unexamined Japanese published patent application JP H7-269512 A Patent document 2: US 3,648,571 A

[0003] US 3,648,571 A discloses a device with a diaphragm in the housing of a vacuum motor. An elastic seal is attached to one right-hand half of the housing. A cup-shaped disc of a piston body is provided on the diaphragm opposite the elastic seal. Summary of the invention: Technical problem

[0004] For example, there is a case where the valve body of the wastegate valve vibrates due to a pressure change inside the turbocharger housing when the wastegate valve opens during turbocharger operation. When the valve body vibrates, the actuating rod connected to the valve body also vibrates.

[0005] The object of the invention is to create a diaphragm-type actuator that can suppress the vibration of the actuating rod. Solution to the problem

[0006] This problem is solved by an actuator having the features of claim 1. Advantageous further developments are the subject of the dependent claims. Effects of the invention

[0007] According to the invention, since it is possible to prevent the holder and the membrane from vibrating due to the elastic element, it is possible to avoid vibration of the actuating rod connected to the membrane. Brief description of the drawings Fig. Figure 1 shows a cross-sectional view of a turbocharger of a vehicle with a diaphragm-type actuator according to an embodiment of the invention. Fig. 2 shows a side view of the in Fig. Figure 1 shows the turbocharger of the vehicle and shows the actuator of the membrane type as attached to a side surface of the turbocharger of the vehicle. Fig. Figure 3 shows a cross-sectional view along a line III-III from Fig. 2. Fig. Figure 4 shows a cross-sectional view of the actuator of the membrane type according to a first embodiment of the invention. Fig. Figure 5 shows a cross-sectional view of an actuator of the membrane type according to a second embodiment of the invention. Fig. Figure 6 shows a cross-sectional view of a membrane-type actuator according to a third embodiment of the invention. Fig. Figure 7 shows a cross-sectional view of a membrane-type actuator according to a fourth embodiment of the invention. Description of the exemplary implementations

[0008] According to one aspect of the invention, a diaphragm-type actuator has been created which drives an actuating rod in an axial direction and which comprises the following: a diaphragm connected to the actuating rod; a low-pressure chamber adjacent to one side of the diaphragm in the axial direction; a high-pressure chamber adjacent to the other side of the diaphragm in the axial direction; a return spring provided in the low-pressure chamber which pushes the diaphragm towards the high-pressure chamber; a retainer provided on a surface close to the high-pressure chamber in the diaphragm; and an elastic element arranged in the axial direction inside the high-pressure chamber between the retainer and a wall surface facing the retainer.

[0009] When the pressure inside the low-pressure chamber of the diaphragm actuator increases from a low-pressure state, the return spring pushes the diaphragm towards the high-pressure chamber, driving the actuating rod towards the opposite end. In this type of actuator, the elastic element is positioned between the holder, located on a surface near the high-pressure chamber within the diaphragm, and a wall surface facing the holder inside the high-pressure chamber. Consequently, as the diaphragm moves towards the high-pressure chamber, the elastic element is sandwiched between the holder and the wall surface facing the holder. This dampens vibration of the holder and diaphragm, thus preventing vibration of the actuating rod connected to the diaphragm.

[0010] The holder can be provided with a rim that projects axially towards the high-pressure chamber, and the elastic element can be positioned so that it faces this rim in the axial direction. This design improves the holder's rigidity because the holder has this rim. Furthermore, because the elastic element faces the rim of the holder, the rim and the elastic element are in contact when the diaphragm moves towards the high-pressure chamber. This prevents contact between the rim and the wall surface facing the rim in the axial direction, thus avoiding vibration of the holder, diaphragm, and actuating rod caused by the elastic element.

[0011] The elastic element can be attached to the inner surface of the wall body facing the high-pressure chamber support. This allows the wall body of the high-pressure chamber to provide stable support for the elastic element. Furthermore, because the elastic element is attached to the wall surface close to the support of the high-pressure chamber wall body, the support and the elastic element are in contact when the diaphragm moves towards the high-pressure chamber. This prevents axial contact between the support and the wall body of the high-pressure chamber and avoids vibration of the support, diaphragm, and actuating rod caused by the elastic element.Furthermore, since the wall body of the high-pressure chamber is provided with the elastic element, it is possible to avoid the vibration of the diaphragm-type actuator by changing the natural frequency of the diaphragm-type actuator, and to avoid the vibration of the actuating rod.

[0012] The actuating rod can extend from the diaphragm to the high-pressure chamber and penetrate a wall body that faces the high-pressure chamber's support in the axial direction. A bearing section holding the actuating rod can be supported by the wall body, and the bearing section can project from the wall body into the high-pressure chamber. The elastic element can be attached to the wall surface, which is a surface near the support within the bearing section. Therefore, since the bearing section supporting the actuating rod is located inside the high-pressure chamber, it does not project to the outside of the high-pressure chamber. Consequently, it is possible to achieve a space saving in the diaphragm-type actuator.Furthermore, since the elastic element is attached to the surface near the holder of the bearing section that projects inside the high-pressure chamber, the holder and the elastic element are in contact with each other when the diaphragm moves towards the high-pressure chamber. Accordingly, it is possible to prevent axial contact between the holder and the wall of the high-pressure chamber and to avoid vibration of the holder, diaphragm, and actuating rod caused by the elastic element. Moreover, since the elastic element is attached to the bearing section that projects from the wall of the high-pressure chamber, it is possible to avoid vibration of the diaphragm actuator by changing its natural frequency and also to avoid vibration of the actuating rod.

[0013] The elastic element can be formed by a rubber element and have a plate-shaped section arranged so that it faces the holder in the axial direction, and the thickness of the plate-shaped section can be oriented in a direction that follows the axial direction. According to this design, an increase in the space required for installing the elastic element can be avoided, and vibration of the holder, diaphragm, and actuating rod can be suppressed while preventing a reduction in the diaphragm's range of motion.

[0014] The elastic element can have an extension section that stretches from the plate-shaped section to the other end. According to this design, since the extension section is in contact with the wall of the high-pressure chamber, the plate-shaped section is positioned so that it is separated (spaced) from the wall of the high-pressure chamber in the axial direction. Then, when the diaphragm moves towards the high-pressure chamber, the holder comes into contact with the plate-shaped section formed by the rubber element, thus suppressing the vibration of the holder, the diaphragm, and the actuating rod.

[0015] Exemplary embodiments of the invention are described in detail below with reference to the drawings. In each drawing, identical or corresponding components are shown using the same reference numerals, and a repeated description is omitted. turbocharger

[0016] One in the Fig. The turbocharger 1 shown in Figures 1 to 3 is a turbocharger of a motor vehicle and is used to compress air supplied to an internal combustion engine (not shown) using exhaust gas emitted by the internal combustion engine. The turbocharger 1 has a diaphragm-type actuator 50 that opens and closes a wastegate valve 20, which is located in Fig. Figure 3 shows the turbocharger 1, which has a turbine 2 and a compressor (a centrifugal compressor) 3. The turbine 2 has a turbine housing 4 and a turbine impeller 6, which is housed in the turbine housing 4. The compressor 3 has a compressor housing 5 and a compressor impeller 7, which is housed in the compressor housing 5.

[0017] The turbine impeller 6 is located at one end of a rotating shaft 14, and the compressor impeller 7 is located at the other end of the rotating shaft 14. A bearing housing 13 is located in a space between the turbine housing 4 and the compressor housing 5. The rotating shaft (rotor shaft) 14 is rotatably supported by the bearing housing 13 via a bearing 15. The turbocharger 1 has a turbine rotor shaft 16, and the turbine rotor shaft 16 has the rotating shaft 14 and the turbine impeller 6, which is located at one end of the rotating shaft 14. The turbine rotor shaft 16 and the compressor impeller 7 rotate as a single unit.

[0018] The turbine housing 4 is provided with an exhaust gas inlet 8 and an exhaust gas outlet 10. Exhaust gas emitted by the internal combustion engine flows into the turbine housing 4 through the exhaust gas inlet 8 to rotate the turbine wheel 6, and it flows to the outside of the turbine housing 4 through the exhaust gas outlet 10.

[0019] The turbine housing 5 is provided with a suction port (suction opening) 9 and a discharge port (discharge opening) 11. When the turbine impeller 6 rotates as described above, the turbine rotor shaft 16 and the compressor impeller 7 also rotate. The rotating compressor impeller 7 draws in ambient air through the suction port 9, compresses the air, and discharges the air from the discharge port 11. The compressed air discharged from the discharge port 11 is supplied to the internal combustion engine. As shown in the Fig. 1 and Fig. Figure 3 shows a bypass channel (see below). Fig. 3) 17, which directs a portion of the exhaust gas introduced from the exhaust gas inlet 8 to the exhaust gas outlet 10 in such a way that the exhaust gas bypasses the turbine impeller 6, is formed inside the turbine housing 4. The bypass channel 17 is a variable gas channel for changing the amount of exhaust gas supplied to the turbine impeller 6. Wastegate valve

[0020] The wastegate valve 20, which is one of the flow rate modification valve mechanisms, is located inside the turbine housing 4. The wastegate valve 20 is a valve that opens and closes an opening section of the bypass channel 17. The wastegate valve 20 has a stem 21, which is rotatably supported by an outer wall of the turbine housing 4, a vibrating element 22 that projects radially from the stem 21, and a valve body 23 that is supported by the vibrating element 22.

[0021] An outer wall of the turbine housing 4 is provided with a support hole 24 that penetrates the outer wall in the direction of the plate thickness. A cylindrical bushing 25 is inserted through the support hole 24. The bushing 25 is fixed to the outer wall of the turbine housing 4.

[0022] The shaft 21 is inserted through the bushing 25 and is rotatably supported by the outer wall of the turbine housing 4. The oscillating piece 22 is fixed to the shaft 21. The shaft 21 rotates about its axis so that the oscillating piece 22 oscillates. A front end of the oscillating piece 22 is provided with a mounting hole for attaching the valve body 23 to it.

[0023] The valve body 23 is capable of contacting and separating from a circumferential edge of the opening section of the bypass channel 17, and is, for example, designed in a disc shape. The valve body 23 is provided with a valve stem 26 that projects towards the opposite side of the opening section of the bypass channel 27. The valve stem 26 is inserted through the mounting hole of the front end of the oscillating piece 22. A stopper 27 is fixed at one end of the valve stem 26, opposite the valve body 23, and the valve stem 26, which is inserted through the mounting hole, is held by the stopper 27. The valve body 23 is supported in such a way that it is slightly movable (including tilting) relative to the oscillating piece 22.Accordingly, since the valve body 23 moves slightly relative to the oscillating element 22, the valve body 23 is in close contact with the circumferential edge of the opening section of the bypass channel 17. Then the valve body 23 is in contact with the circumferential edge of the opening section of the bypass channel 17 such that the wastegate valve 20 is closed, and the valve body 23 moves away from the circumferential edge of the opening section of the bypass channel 17 such that the wastegate valve 20 is opened.

[0024] A plate-shaped connecting element 28, projecting radially from the shaft 21, is fixed in the shaft 21 at one end, which is located on the outside of the turbine housing 4. A front end of the connecting element 28 is provided with a mounting hole through which a connecting pin 29 is inserted. The connecting pin 29 is also inserted through a mounting hole formed at the other end 51b, which is a front end of the actuating rod 51 of the diaphragm-type actuator 50 described below. One end of the connecting pin 29 is secured to the actuating rod 51 by crimping. A clip 30 is attached to the other end of the connecting pin 29 to prevent it from loosening from the mounting hole.The shaft 21 is connected to the actuating rod 51 of the actuator 50 of the membrane type by the connecting element 28 and the connecting pin 29. Membrane type actuator

[0025] The actuator 50 of the membrane type is described below. As this is shown in the Fig. 2 and Fig. As shown in Figure 3, the actuator 50 of the membrane type is fixed to a bracket 18 which projects laterally from the compressor housing 5.

[0026] As this is in Fig. As shown in Figure 4, the diaphragm-type actuator 50 has an actuating rod 51 and an actuator body 52, which drives the actuating rod 51 in the axial direction. The actuator body 52 has a diaphragm 53 connected to the actuating rod 51 and transmits a driving force to the actuating rod 51, a low-pressure chamber 54 adjacent to one side of the diaphragm 53, a high-pressure chamber 55 adjacent to the other side of the diaphragm 53, and a return spring 56 located inside the low-pressure chamber 54, which pushes the diaphragm 53 towards the high-pressure chamber 55. In other words, the low-pressure chamber 54 and the high-pressure chamber 55 are arranged such that the diaphragm 53 is positioned between them, and the return spring 56 pushes the diaphragm 53 towards the high-pressure chamber 55. The actuating rod 51 is a rod-shaped element that is driven by the actuator body 52.

[0027] The actuator body 52 has a low-pressure-side cup section 58, which forms the low-pressure chamber 54, and a high-pressure-side cup section 59, which forms the high-pressure chamber 55. The low-pressure-side cup section 58 and the high-pressure-side cup section 59 are made of metal, such as iron. The low-pressure-side cup section 58 has a cylindrical section 58a and a rear wall 58b (back wall) that closes one end (the right side in the drawing) of the cylindrical section 58a. The other end of the cylindrical section 58a is provided with a flange section 58c that projects from the circumferential edge of the opening section in the radial direction of the cylindrical section 58a. Furthermore, the cylindrical section 58a is provided with a nozzle 58d.A (not shown) vacuum pump, which can reduce the pressure inside the low-pressure chamber 54 to a vacuum state, is connected to the nozzle 58d.

[0028] The high-pressure side cup section 59 has a cylindrical section 59a and a front wall (a wall body) 59b that closes the other end (a left side in the drawing) of the cylindrical section 59a. One end of the cylindrical section 59a is provided with a flanged section 59c that projects from the circumferential edge of the opening section in the radial direction of the cylindrical section 59a. The inner diameter of the cylindrical section 59a of the high-pressure side cup section 59 corresponds to the inner diameter of the cylindrical section 58a of the low-pressure side cup section 58. Furthermore, the inner diameters of the cylindrical sections 58a and 59a can be the same or different. Additionally, a central section of the front wall 59b is provided with an opening through which the actuating rod 51 is inserted.

[0029] The low-pressure side cup section 58 and the high-pressure side cup section 59 are arranged such that their opening sections face each other, with the diaphragm 53 positioned between them in the axial direction of the actuating rod 51, and they are connected to each other. The diaphragm 53 is, for example, circular in shape, and a circumferential edge of the diaphragm 53 is sandwiched between the flange sections 58c and 59c of the low-pressure side cup section 58 and the high-pressure side cup section 59. The flange sections 58c and 59c of the low-pressure side cup section 58 and the high-pressure side cup section 59 are connected to each other, for example, by riveting. The low-pressure side cup section 58 and the high-pressure side cup section 59 can be connected to each other, for example, by welding, bolting, or other methods.

[0030] The diaphragm 53 has an outer diameter that is larger than the inner diameters of the cylindrical sections 58a and 59a. Inside the low-pressure side cup section 58 and the high-pressure side cup section 59, the central section of the diaphragm 53 is movable in the axial direction of the actuating rod 51.

[0031] One surface (on the right side of the drawing) of the diaphragm 53 is provided with a low-pressure-side holder 61, and the other surface (on the left side of the drawing) of the diaphragm 53 is provided with the high-pressure-side holder 62. The low-pressure-side holder 61 and the high-pressure-side holder 62 are, for example, made of metal such as iron. The low-pressure-side holder 61 has a disc-shaped holder body 61a that is in contact with one surface of the diaphragm 53, and a projecting section 61b that extends from the outer circumferential edge of the holder body 61a in the axial direction of the actuating rod 51. The high-pressure-side holder 62 has a disc-shaped holder body 62a that is in contact with the other surface of the diaphragm 53, and a projecting section (an edge) 62b that extends from the outer circumferential edge of the holder body 62a in the axial direction of the actuating rod 51.The outer diameter of the holder body 62a of the high-pressure-side holder 62 is smaller than the outer diameter of the holder body 61a of the low-pressure-side holder 61. Furthermore, each of the middle sections of the holder bodies 61a and 62a is provided with an opening section.

[0032] One end 51a of the actuating rod 51 is connected to the diaphragm 53. More precisely, one end 51a of the actuating rod 51 is inserted through an opening section of the high-pressure-side holder 62, the opening section of the diaphragm 53, and under the opening section of the low-pressure-side holder 61, and fixed to the high-pressure-side holder 62 and the low-pressure-side holder 61, for example, by crimping. The high-pressure-side holder 62 and the low-pressure-side holder 61 support the middle section of the diaphragm 53, while the middle section is sandwiched between the actuating rod 51 on both sides in the axial direction.

[0033] Furthermore, the method for connecting the actuating rod 51 and the diaphragm 53 is not limited to the joining method by riveting. For example, a joining method can be used in which one end of the actuating rod 51 is provided with a threaded section and a nut is attached to the threaded section such that the actuating section 51 is connected to the diaphragm 53 by the high-pressure-side holder 62 and the low-pressure-side holder 61.

[0034] The return spring 56 is, for example, a compression helical spring (compression coil spring), wherein one end of the return spring 56 is in contact with the rear wall 58b of the low-pressure-side cup section 58, and the other end of the return spring 56 is in contact with the retaining body 61 of the low-pressure-side holder 61. The return spring 56 can be extended and compressed in the axial direction of the actuating rod 51, and when the low-pressure-side holder 61 is forced towards the high-pressure chamber 55, the diaphragm 53 is forced towards the high-pressure chamber 55.

[0035] The actuating rod 51 extends from the diaphragm 53 to the high-pressure chamber 55, penetrates the front wall 59 of the high-pressure side cup section 59, and extends to the outside of the high-pressure chamber 55. A bearing section 63, which holds the actuating rod 51, is provided at a position corresponding to the opening section of the front wall 59b.

[0036] The bearing section 63 has a cylindrical bushing 64 and a bushing housing 65 that receives the bushing 64. The bushing housing 65 has a cylindrical section 65a, a rear wall (a wall body) 65b, and a flanged section 65c. The cylindrical section 65a is arranged to cover an outer circumferential surface of the bushing 64. The rear wall 65b is formed at one end face of the cylindrical section 65a such that it projects radially inward. A central section of the rear wall 65b is provided with an opening through which the actuating rod 51 is inserted. The rear wall 65b is arranged to cover an end face at one end face of the bushing 64.

[0037] The flange section 65c is formed at the other end of the cylindrical section 65a such that it projects outwards in the radial direction. The flange section 65c is fixed to an inner wall surface (an inner surface) of the front wall 59b of the high-pressure-side cup section 59. The flange section 65c is connected to the high-pressure-side cup section 59, for example, by welding. The bushing 64 is arranged between the front wall 59b of the high-pressure-side cup section 59 and the rear wall 65b of the bushing housing 65 in the axial direction of the actuating rod 51.

[0038] The bushing housing 65 is arranged such that it projects inwards from the front wall 59b. In other words, the rear wall 65b of the bushing housing 65 is located near the diaphragm 53 with respect to the front wall 59b of the high-pressure side cup section 59. The rear wall 65b of the bushing housing 65 faces the high-pressure side holder 62 in the axial direction of the actuating rod 51.

[0039] In this case, the actuator 50 of the membrane type has an anti-vibration sheet (an elastic element) 66 between the high-pressure side holder 62 and the rear wall 65b of the bushing housing 65 in the axial direction of the actuating rod 51 inside the high-pressure chamber 55.

[0040] The anti-vibration plate 66 is, for example, a ring-shaped rubber plate (a plate-shaped section). A central opening section of the anti-vibration plate 66 is an opening through which the actuating rod 51 is inserted. The outer diameter of the anti-vibration plate 66 corresponds to the outer diameter of the rear wall 65b of the bushing housing 65. Furthermore, the anti-vibration plate 66 is arranged such that the thickness direction of the anti-vibration plate 66 follows the axial direction of the actuating rod 51. One surface of the anti-vibration plate 66 is arranged to face the holder body 62a of the high-pressure-side holder 62, and the other surface of the anti-vibration plate 66 is arranged to face the inner wall surface (the wall surface facing the holder) of the rear wall 65b of the bushing housing 65.The anti-vibration sheet 66 is attached to the inner wall surface of the rear wall 65b of the socket housing 65, for example by tack welding.

[0041] The material of the anti-vibration plate 66 is, for example, heat-resistant rubber such as silicone rubber or chloroprene rubber. The temperature inside the high-pressure chamber 55 is, for example, approximately 100°C in the operating condition of the turbocharger 1.

[0042] The operation and effect of turbocharger 1 are described below.

[0043] Exhaust gas flowing from the exhaust inlet 8 passes through the turbine spiral channel 4a and is supplied to the inlet side of the turbine impeller 6. A rotational force is generated by applying the pressure of the exhaust gas supplied by the turbine impeller 6, causing the rotating shaft 14 and the compressor impeller 7 to rotate together with the turbine impeller 6. Accordingly, air drawn in through the intake port 9 of the compressor 3 is compressed by the compressor impeller 7. The compressed air passes through a diffuser channel 5a and a compressor spiral channel 5b and is discharged through the discharge port 11. The air discharged through the discharge port 11 is supplied to the internal combustion engine.

[0044] For example, if the boost pressure (the pressure of the air discharged from the discharge port 11) is lower than the set pressure during operation of the turbocharger 1, a vacuum is applied to the low-pressure chamber 54 of the diaphragm actuator 50 by the vacuum pump. At this point, the pressure inside the high-pressure chamber 55 is higher than the pressure inside the low-pressure chamber 54. The diaphragm 53 is then forced by the pressure inside the high-pressure chamber 55, causing the central section of the diaphragm 53 to move towards the low-pressure chamber 54. The return spring 56 is compressed.

[0045] In a state where a vacuum is applied to the low-pressure chamber 54, the central section of the diaphragm 53 approaches the rear wall 58b of the low-pressure side cup section 58. The actuating rod 51 is pulled axially to one end, and a tensile force exerted by the actuating rod 51 is transmitted to the valve body 23 via the connecting element 28, which is connected to the actuating rod 51, the stem 21, and the vibrating piece 22. Consequently, the valve body 23 is pressed against the circumferential edge of the opening section of the bypass channel 17, and the wastegate valve 20 is closed. That is, in the turbine 2, exhaust gas bypass operation is not carried out using the bypass channel 17.

[0046] Then, when the boost pressure reaches the set pressure during operation of turbocharger 1, the application of vacuum using the vacuum pump is stopped. Thus, the pressure inside the low-pressure chamber 54 increases and becomes close to the pressure inside the high-pressure chamber 55. At this point, the compressed return spring 56 is extended, the diaphragm 53 is forced by the return spring 56, and the central section of the diaphragm 53 moves towards the high-pressure chamber 55.

[0047] When the central section of the diaphragm 53 moves towards the high-pressure chamber 55, the actuating rod 51 moves to the opposite end in the axial direction in accordance with the movement of the central section of the diaphragm 53. The actuating rod 51 is pushed to the opposite end in the axial direction, and a force exerted by the actuating rod 51 is transmitted to the connecting element 28. The connecting element 28 pivots about the center of the shaft 21, and the oscillating element 22 oscillates about the axis due to the rotation of the shaft 21. Consequently, the valve body 23 is separated from the circumferential edge of the opening section of the bypass channel 17, and the wastegate valve 20 is opened. Accordingly, part of the exhaust gas flowing in from the exhaust inlet 8 passes through the bypass channel 17 and bypasses the turbine impeller 6. For this reason, it is possible to reduce the amount of exhaust gas supplied to the turbine impeller 6.

[0048] When the central section of the diaphragm 53 moves towards the high-pressure chamber 55 to its maximum position while the wastegate valve 20 is open, the retaining body 62a of the high-pressure-side holder 62 comes into contact with the anti-vibration plate 66. In other words, the anti-vibration plate 66 is sandwiched between the retaining body 62a and the rear wall 65b of the bushing housing 65 in the axial direction of the actuating rod 51.

[0049] In this state, for example when the vibrating body 23 vibrates, the vibration of the valve body 23 is transmitted to the vibrating element 22, the stem 21, the connecting element 28, the actuating rod 51, the diaphragm 53, and the high-pressure-side holder 62. However, the vibration of the high-pressure-side holder 62 is reduced by the anti-vibration plate 66. Accordingly, since the vibration of the high-pressure-side holder 62 is suppressed, the vibration of the diaphragm 53, the actuating rod 51, the connecting element 28, the stem 21, the vibrating element 22, and the valve body 23 is also suppressed.

[0050] Since the anti-vibration plate 66 is attached to the inner wall surface of the rear wall 65b of the bushing housing 65 in the actuator 50 of the diaphragm type, contact between the high-pressure-side holder 62 and the rear wall 65b is prevented. Therefore, there is no need to worry about abnormal noise caused by the high-pressure-side holder 62 striking the rear wall 65b. Furthermore, since the bushing housing 65 projects towards the high-pressure-side holder 62 with respect to the front wall 59b of the high-pressure-side cup section 59, the high-pressure-side holder 62 contacts the anti-vibration plate 66 before it contacts the front wall 59b. Therefore, there is no need to worry about abnormal noise caused by the high-pressure-side holder 62 striking the high-pressure-side cup section 59.

[0051] Since the anti-vibration plate 66 is attached to the bushing housing 65 of the diaphragm-type actuator 50, the natural frequency of the actuator body 52 can be changed. Thus, it is possible to suppress the vibration of the actuator 52 and the vibration of the actuating rod 51. Accordingly, it is possible to suppress the vibration of the actuating rod 51 and the vibration of the valve body 23. Second embodiment

[0052] Below is an actuator 50B of the membrane type according to a second embodiment with reference to Fig. 5 described. The actuator 50B of the diaphragm type according to the second embodiment differs from the actuator 50 of the diaphragm type of the first embodiment in that a compression helical spring (an elastic element) 67 is provided instead of the anti-vibration plate 66. Furthermore, the part of the description that also applies to the first embodiment has been omitted from the description of the second embodiment.

[0053] The compression coil spring 67 is arranged between the rear wall 65b of the bushing housing 65 and the retaining body 62a in the axial direction of the actuating rod 51. The compression coil spring 67 is arranged so that it is coaxial with the actuating rod 51, with one end of the compression coil spring 67 in contact with the retaining body 62a and the other end of the compression coil spring 67 in contact with the wall surface of the rear wall 65b.

[0054] The outer diameter of the compression coil spring 67 corresponds, for example, to the outer diameter of the rear wall 65b. The spring constant of the compression coil spring 67 is less than the spring constant of the return spring 56, which is located inside the low-pressure chamber 54, and is, for example, 1 / 10 to 1 / 5 of the spring constant of the return spring 56. If, for example, the pressure inside the high-pressure chamber 55 is the same as the pressure inside the low-pressure chamber 54, the central section of the diaphragm 53 is forced by the return spring 56 so that it moves towards the high-pressure chamber 55, and the compression coil spring 67 is compressed.

[0055] According to the actuator 50B of the diaphragm type of the second embodiment, when the valve body 23 oscillates in such a way that the oscillation is transmitted to the diaphragm 53 and the high-pressure-side holder 62, the oscillation of the high-pressure-side holder 62 and the diaphragm 53 is reduced by the compression coil spring 67 so that the oscillation of the actuating rod 51 is suppressed. For this reason, the oscillation of the valve body 23 of the actuator 50 of the diaphragm type is suppressed.

[0056] Since the high-pressure side holder 62 and the compression spiral spring 67 of the diaphragm type actuator 50B are in contact with each other even when the valve is not fully open, the oscillation of the actuating rod 51 is suppressed regardless of the degree of opening of the valve.

[0057] Furthermore, in the second embodiment, the other end of the compression coil spring 67 is arranged such that it is in contact with the rear wall 65b of the bushing housing 65. However, the other end of the compression coil spring 67 can, for example, be arranged such that it is in contact with the inner wall surface of the front wall 59b of the high-pressure-side cup section 59. The compression coil spring 67 can also be provided in a variety of positions. For example, the compression coil spring can be arranged on the outside of the actuating rod 51 such that the actuating rod 51 is not inserted through it.

[0058] The axial length of the compression coil spring 67 can be shorter than the distance between the rear wall 65b and the holder body 62a. For example, a configuration can also be used in which the other end of the compression coil spring 67 is attached to the rear wall 65b and one end of the compression coil spring 67 is positioned so that it is separated from the holder body 62a. In this configuration, when the movement of the diaphragm 53 to the high-pressure chamber 55 increases, the holder body 62a and the compression coil spring 67 come into contact with each other in such a way that the vibration of the high-pressure-side holder 62a is reduced.

[0059] Another configuration can be used in which one end of the compression coil spring 67 is attached to the holder body 62a and the other end of the compression coil spring 67 is arranged so that it is separated from the rear wall 65b. In this configuration, when the movement of the diaphragm 53 to the high-pressure chamber 55 increases, the rear wall 65b and the compression coil spring 67 come into contact with each other in such a way that the vibration of the high-pressure-side holder 62 is reduced. Third example

[0060] Below is an actuator 50C of the membrane type according to a third embodiment with reference to Fig. The actuator 50C of the diaphragm type of the third embodiment differs from the actuator 50 of the diaphragm type of the first embodiment in that a bearing section 68, which is arranged to project from the front wall 59b to the outside of the high-pressure chamber 55, is provided instead of the bearing section 63, which is arranged to project from the front wall 59b to the inside of the high-pressure chamber 55, and an anti-vibration plate 69, which is attached to the inner wall surface of the front wall 59b, is provided instead of the anti-vibration plate 66, which is attached to the rear wall 65b of the bushing housing 65. Furthermore, the description in the third embodiment, which would be the same as in the first and second embodiments, is omitted.

[0061] The bearing section 68 has the bushing 64 and the bushing housing 65. The bushing housing 65 has the cylindrical section 65a and a front wall 65d. The cylindrical section 65a is designed to project from the front wall 59b of the high-pressure-side cup section 59 to the other end of the actuating rod 51. One end of the cylindrical section 65a is continuous with the front wall 59b of the high-pressure-side cup section 59. The front wall 65d of the bushing housing 65 is designed at the other end of the cylindrical section 65a to project radially inward from the cylindrical section 65a. A central section of the front wall 65d is provided with an opening through which the actuating rod 51 is inserted. The front wall 65d is arranged to cover the end face of the other end of the bushing 64.

[0062] The anti-vibration plate 69 is, for example, a disc-shaped rubber plate (a plate-shaped section). A central section of the anti-vibration plate 69 is provided with an opening through which the actuating rod 51 is inserted. Furthermore, the outer diameter of the anti-vibration plate 69 is a dimension that is larger than the outer diameter of the projecting section 62b of the high-pressure-side holder 62. The anti-vibration plate 69 is attached to the front wall 59b, for example, by tack welding.

[0063] In the actuator 50C of the diaphragm type with this design, when the movement of the central section of the diaphragm 53 to the high-pressure chamber 55 reaches its maximum, the end face of the projecting section 62b of the high-pressure-side holder 62 comes into contact with the anti-vibration plate 69. Accordingly, when the vibration of the valve body 23 is transmitted to the diaphragm 53 and the high-pressure-side holder 62, the vibration of the high-pressure-side holder 62 and the diaphragm 53 is reduced by the anti-vibration plate 69. Therefore, since the vibration of the actuating rod 51 is suppressed, the vibration of the valve body 23 of the actuator 50 of the diaphragm type is also suppressed. Furthermore, in the third embodiment, the anti-vibration plate 69 is attached to the front wall 59b; however, the anti-vibration plate can, for example, be attached to the high-pressure-side holder 62.For example, the anti-vibration sheet can be formed in a ring-like shape and can be arranged to cover the end surface of the projecting section 62b of the high-pressure side holder 62. Fourth embodiment

[0064] Below is an actuator 50D of the membrane type according to a fourth embodiment with reference to Fig. 7. The actuator 50D of the membrane type according to the fourth embodiment differs from the actuator 50C of the membrane type of the third embodiment in that an anti-vibration blade 70 is provided instead of the anti-vibration blade 69. Furthermore, the description of the fourth embodiment, which would be the same as for the first, second, and third embodiments, has been omitted.

[0065] The anti-vibration blade 70, for example, is a plate-shaped rubber element formed in a conical, frustoconical, mountain-like shape. The anti-vibration blade 70 has a rear surface section (a plate-shaped section) 70a, which is formed in a disc shape and arranged so that it is separated from the front wall 59b, a cylindrical section (an extension section) 70b, which extends to the front wall 59b from an outer circumferential edge of the rear surface section 70a, and a flange section 70c, which projects radially outwards from an end near the front wall 59b in the cylindrical section 70b.

[0066] The rear surface section 70a is located near the diaphragm 53, while it is separated from the front wall 59b in the axial direction of the actuating rod 51. A predetermined space is formed between the rear surface section 70a and the front wall 59b. A central section of the rear surface section 70a is provided with an opening through which the actuating rod 51 is inserted. The rear surface section 70a forms a wall surface facing the high-pressure-side holder 62 in the axial direction of the actuating rod 51. The outer diameter of the rear surface section 70a is, for example, a dimension that is smaller than the inner diameter of the projecting section 62b of the high-pressure-side holder 62.

[0067] The cylindrical section 70b is conically shaped, and its inner diameter increases as it approaches the front wall 59b. In the axial direction of the actuating rod 51, one end of the cylindrical section 70b is connected to the rear surface section 70a, and the other end of the cylindrical section 70b is in contact with the inner surface of the front wall 59b. The outer diameter of the other end of the cylindrical section 70b is larger than the outer diameter of one end of it and smaller than, for example, the inner diameter of the projecting section 62b of the high-pressure-side holder 62.

[0068] The flange section 70c is arranged such that it faces, for example, the projecting section 62b of the high-pressure-side holder 62 in the axial direction of the actuating rod 51. The flange section 70c is attached to the inner wall surface of the front wall 59b, for example, by tack welding. The outer diameter of the flange section 70c can be larger than the outer diameter of the projecting section 62b of the high-pressure-side holder 62, or it can be smaller than the outer diameter of the projecting section 62b.

[0069] The anti-vibration blade 70 can, for example, be formed by a plate-shaped rubber element. The anti-vibration blade 70 can be formed by pressing a rubber element against a base that forms a conical, truncated cone-like mountain shape.

[0070] In the diaphragm actuator 50D with this configuration, when the movement of the central section of the diaphragm 53 to the high-pressure chamber 55 reaches its maximum, the retaining body 62a of the high-pressure-side holder 62 comes into contact with the rear surface section 70a of the anti-vibration plate 70. Accordingly, the vibration of the valve body 23 is transmitted to the diaphragm 53 and the high-pressure-side holder 62, and the vibration of the high-pressure-side holder 62 and the diaphragm 53 is reduced by the anti-vibration plate 70. Therefore, since the vibration of the actuating rod 51 is suppressed, the vibration of the valve body 23 of the diaphragm actuator 50 is also suppressed.

[0071] Furthermore, in the fourth embodiment, the anti-vibration plate 70 is attached to the front wall 59b similarly to the third embodiment; however, the anti-vibration plate 70 can, for example, be attached to the high-pressure-side holder 62. For example, the outer diameter of the rear surface section 70a of the anti-vibration plate 70 can be larger than the outer diameter of the projecting section 62b of the high-pressure-side holder 62, and the rear surface section 70a can be arranged such that it covers the end surface of the projecting section 62b.

[0072] The mountain shape formed on the anti-vibration blade 70 is not limited to a conical, frustoconical shape. For example, the shape can be cylindrical or rectangular, parallelepiped-like.

[0073] Furthermore, the side surface of the mountain shape is not limited to a cylindrical shape and can include a variety of foot-shaped extension sections arranged at intervals in the circumferential direction.

[0074] The anti-vibration blade 70 has the flanged section 70c, but it need not have the flanged section 70c. Furthermore, the anti-vibration blade 70 can have a flanged section that is formed at one end near the front wall 59b in the cylindrical section 70b such that it projects radially inwards, or it can have a disc-shaped front section that closes one end near the front wall 59b in the cylindrical section 70b.

[0075] Furthermore, the invention is not limited to the embodiments described above, and various modifications can be discussed as below without deviating from the scope of the claims.

[0076] In the embodiments described above, the diaphragm actuator 50 is used as a drive source for the wastegate valve 20 of the turbocharger 1; however, it can also be used as a drive source for opening and closing other valves. For example, the diaphragm actuator 50 can be used as a drive source to actuate an object other than a valve.

[0077] In the embodiments described above, the anti-vibration leaves 66, 69, and 70 and the compression coil spring 67 are listed as examples of the elastic element; however, the elastic element can, for example, comprise other spring elements such as a disc spring or a leaf spring. For example, a plurality of the same type of spring elements can be arranged to overlap each other in the axial direction of the actuating rod 51, or a plurality of types of spring elements can be arranged to overlap each other in the axial direction of the actuating rod 51. For example, a plurality of anti-vibration leaves 69, which are arranged in Fig.The anti-vibration sheets shown in Figure 6 overlap each other, or a variety of different types of anti-vibration sheets with different thicknesses or materials can overlap each other. Furthermore, the anti-vibration sheet 70 can be arranged near the diaphragm 53 in the anti-vibration sheet 69. Additionally, the compression coil spring can be arranged near the diaphragm 53 in the anti-vibration sheets 66, 69, and 70, or the compression helical spring can be arranged near the front wall 59b in the anti-vibration sheets 66, 69, and 70.

[0078] In the embodiments described above, a case in which the elastic element is attached to the rear wall 65b of the bushing housing 65, a case in which the elastic element is attached to the front wall 59b of the high-pressure-side cup section 59, and a case in which the elastic element is attached to the high-pressure-side holder 62 are given as examples; however, the elastic element can be attached to other sections. For example, the elastic element can be attached to the inner circumferential surface of the cylindrical section 59a of the high-pressure-side cup section 59, or it can be attached to the high-pressure-side cup section 59 via other elements.

[0079] In the embodiments described above, the high-pressure-side holder 62 has the projecting section 62b, which extends towards the inside of the high-pressure chamber 55. However, the high-pressure-side holder 62 need not have the projecting section 62b extending towards the inside of the high-pressure chamber 55. Furthermore, the projecting section 62b need not extend from the outer circumferential section of the holder body 62a, but may extend from an intermediate section (middle section) in the radial direction.

[0080] In the embodiments described above, the turbocharger 1, which uses the wastegate valve 20, is used for the vehicle; however, the turbocharger is not limited to use in a vehicle. For example, the turbocharger can be used for a marine internal combustion engine or for other internal combustion engines. Industrial applicability

[0081] According to some aspects of the invention, since it is possible to suppress the vibration of the holder and the diaphragm by the elastic element, it is possible to suppress the vibration of the actuating rod that is connected to the diaphragm. Reference symbol list 1 turbocharger 50, 50B, 50C, 50D diaphragm type actuator 51 Actuating rod 52 actuator bodies 53 Membran 54 Low-pressure chamber 55 High-pressure chamber 56 Return spring 59b front wall (wall surface facing the holder) 62 high-pressure side holders 62b Leading section (edge) 63 Storage section 65b rear wall (wall facing the holder) 66, 69, 70 Anti-vibration sheet (elastic element, plate-shaped rubber, conical frustoconical rubber) 67 Compression spiral spring (elastic element) 70a rear surface section (plate-shaped section) 70b cylindrical section (extension section)

Claims

[1] Actuator of the membrane type, which drives an actuating rod (51) in an axial direction of the actuating rod (51), comprising: a membrane (53) which is connected to the actuating rod (51); a low-pressure chamber (54) adjacent to an end face of the membrane (53) in the axial direction; a high-pressure chamber (55) which is adjacent to the other end of the membrane (53) in the axial direction; a return spring (56) which is provided in the low-pressure chamber (54) and pushes the diaphragm (53) towards the high-pressure chamber (55); a holder (62) which is provided on a surface near the high-pressure chamber (55) in the membrane (53); and an elastic element (66, 69, 70) which is arranged between the holder (62) and a wall surface which faces the holder (62) in the axial direction inside the high pressure chamber (55), wherein the actuating rod (51) extends from the diaphragm (53) to the high-pressure chamber (55) and penetrates a wall body (59b) which faces the holder of the high-pressure chamber (55) in the axial direction, wherein a bearing section (63) which holds the actuating rod (51) is supported by the wall body (59b), wherein the bearing section (63) projects from the wall body (59b) into the high-pressure chamber (55), wherein the elastic element (66, 69, 70) is attached to a surface (65b) which is near the holder (62) in the bearing section (63), and wherein the holder (62) is constructed in such a way that it comes into contact with the elastic element (66, 69, 70) when the membrane (53) moves towards the high pressure chamber (55) to a maximum. [2] Actuator of the membrane type according to claim 1, wherein the elastic element (70) is formed by a rubber element and has a plate-shaped section (70a) which is arranged such that it faces the holder (62) in the axial direction, and wherein a plate thickness direction of the plate-shaped section (70a) is arranged such that it follows the axial direction. [3] Actuator of the membrane type according to claim 2, wherein the elastic element (70) has an extension section (70b) extending from the plate-shaped section (70a) to the other end side.

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