JP2018105245A - Actuator - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an actuator whose sliding resistance is small and which has a guide part and a shaft hard to wear.SOLUTION: An actuator 1 includes an oscillation guide part 2 having a partially reverse-spherical oscillation guide surface 22, a linear guide part 3 having a partially spherical oscillation guided surface 30 slide-contacting the slide guide surface 22 at its inside and a straight tubular shaft insertion hole 31, and capable of oscillating relative to the oscillation guide part 2, and a shaft 4 inserted through the shaft insertion hole 31 and capable of linearly reciprocating relative to the linear guide part 3.SELECTED DRAWING: Figure 2

Description

  The present invention relates to an actuator used to drive, for example, a waste gate valve disposed in an exhaust passage of a vehicle.

  For example, as shown in Patent Document 1, a bypass passage that does not pass through a turbine impeller is disposed in an exhaust passage of a vehicle with a turbocharger. A waste gate valve is disposed in the bypass passage for adjusting the passage area. The actuator drives the waste gate valve.

  FIG. 4 shows an axial sectional view of a conventional actuator. As shown in FIG. 4, a cylindrical guide portion 104 is disposed on the boss portion 103 of the bottom wall portion 102 of the casing 101 of the actuator 100. An O-ring 105 is disposed between the outer peripheral surface of the guide portion 104 and the inner peripheral surface of the boss portion 103. A shaft 106 is inserted inside the guide portion 104 in the radial direction. The shaft 106 can reciprocate in a linear direction along the inner peripheral surface of the guide portion 104. The actuator 100 drives a waste gate valve by the shaft 106.

JP 2016-17619 A

  However, the shaft 106 may swing while reciprocating in the linear direction. The guide part 104 is fixed to the boss part 103 of the casing 101. For this reason, it cannot swing following the swing of the shaft 106. Therefore, the guide part 104 and the shaft 106 are easily worn. SUMMARY OF THE INVENTION An object of the present invention is to provide an actuator that has low sliding resistance and is less likely to wear a guide portion and a shaft.

  In order to solve the above problems, an actuator of the present invention includes a swing guide portion having a partially back spherical swing guide surface, and a partially spherical swing guided surface that is in sliding contact with the swing guide surface from the inside. A linear guide portion having a straight tubular shaft insertion hole and swingable with respect to the swing guide portion, and being inserted into the shaft insertion hole and reciprocating linearly with respect to the linear guide portion. And a possible shaft. Here, the “back spherical shape” refers to a shape of a spherical surface viewed from the back side (center side of the sphere), that is, a surface shape that is type-symmetric with the spherical surface.

  The shaft can reciprocate linearly, that is, reciprocate in a linear direction with respect to the linear motion guide portion. In addition, the linear motion guide portion can swing relative to the swing guide portion. For this reason, according to the actuator of this invention, a shaft can be linearly moved and rock | fluctuated with respect to the rocking | fluctuation guide part. Therefore, sliding resistance can be reduced, and wear of the guide part (swing guide part, linear guide part) and shaft (wear of at least one of the swing guide part, linear guide part, and shaft) is reduced. Can be suppressed.

It is an arrangement plan of actuators of one embodiment of the present invention. It is an axial sectional view of the actuator. FIG. 3 is an enlarged view in a circle III in FIG. 2. It is an axial sectional view of a conventional actuator.

  Hereinafter, embodiments of the actuator of the present invention will be described.

<Actuator arrangement and configuration>
First, the arrangement and configuration of the actuator of this embodiment will be described. FIG. 1 shows a layout of actuators according to an embodiment of the present invention. As shown in FIG. 1, a turbocharger 92 is disposed between the intake system 90 and the exhaust system 91. The bypass passage 910 bypasses the turbocharger 92. A waste gate valve 911 is disposed in the bypass passage 910. The actuator 1 drives the waste gate valve 911.

  FIG. 2 shows a sectional view in the axial direction (vertical direction) of the actuator. FIG. 3 shows an enlarged view in the circle III of FIG. As shown in FIG. 2, the actuator 1 includes a swing guide portion 2, a linear motion guide portion 3, a shaft 4, a casing 5, a diaphragm 6, a pipe 70, an insulator (heat insulating material) 71, a plate 72 and a spring 73.

  The casing 5 includes a first casing part 50 and a second casing part 51. The first casing portion 50 has a bottomed cylindrical shape that opens upward. The first casing part 50 includes a peripheral wall part 500, a bottom wall part 501, and a first pressure chamber 502. The peripheral wall portion 500 has a cylindrical shape extending in the vertical direction. The bottom wall portion 501 seals the lower end opening of the peripheral wall portion 500. A through hole 501a is formed in the center of the bottom wall portion 501 in the radial direction. The first pressure chamber 502 is disposed inside the first casing portion 50. An atmospheric pressure is introduced into the first pressure chamber 502 through a vent hole (not shown) provided in the first casing portion 50.

  The second casing portion 51 has a bottomed cylindrical shape that opens downward. The second casing part 51 is laid in the upper end opening of the first casing part 50. The second casing part 51 includes a peripheral wall part 510, a bottom wall part 511, and a second pressure chamber 512. The peripheral wall 510 has a cylindrical shape extending in the vertical direction. The bottom wall portion 511 seals the upper end opening of the peripheral wall portion 510. A through hole 511a is formed in the center of the bottom wall portion 511 in the radial direction. The second pressure chamber 512 is disposed inside the second casing portion 51. A negative pressure (pressure less than atmospheric pressure) is introduced into the second pressure chamber 512 via a pipe 70 described later.

  The insulator 71 is disposed on the lower side (outside) of the bottom wall portion 501 of the first casing portion 50. The insulator 71 is fixed to the bracket 93. A through-hole 710 is formed in the insulator 71. The through hole 501a and the through hole 710 are continuous in the vertical direction.

  The diaphragm 6 is made of rubber, for example, and has flexibility. The diaphragm 6 is disposed between the first casing part 50 and the second casing part 51. The diaphragm 6 hermetically partitions the first pressure chamber 502 at atmospheric pressure and the second pressure chamber 512 at negative pressure. The diaphragm 6 can be elastically deformed by a pressure difference between the first pressure chamber 502 and the second pressure chamber 512. The outer peripheral edge of the diaphragm 6 is sandwiched and fixed between the opening edge of the peripheral wall portion 500 of the first casing portion 50 and the opening edge of the peripheral wall portion 510 of the second casing portion 51. A through hole 60 is formed in the center of the diaphragm 6 in the radial direction.

  As shown in FIG. 3, the swing guide part 2 includes a first guide part 20, a second guide part 21, and a swing guide surface 22. The first guide portion 20 has a cylindrical shape extending in the vertical direction. The first guide portion 20 is disposed in the through hole 710. The second guide portion 21 is disposed on the upper side of the first guide portion 20. The second guide portion 21 has a cylindrical shape extending in the vertical direction. The second guide portion 21 is disposed in the through hole 501a. A support surface 210 is disposed on the upper surface of the second guide portion 21. The swing guide surface 22 has a partially back spherical shape with the center A as the center. The swing guide surface 22 is disposed on the inner peripheral surfaces of the first guide portion 20 and the second guide portion 21. Specifically, the lower half of the swing guide surface 22 is disposed on the first guide portion 20. Further, the upper half of the swing guide surface 22 is disposed in the second guide portion 21.

  As shown in FIG. 3, the linear motion guide portion 3 is accommodated inside the swing guide portion 2. The linear motion guide portion 3 can swing around the center A with respect to the swing guide portion 2. The linear motion guide portion 3 has a cylindrical shape. The linear motion guide unit 3 includes a swing guided surface 30 and a shaft insertion hole 31. The swing guided surface 30 has a partial spherical shape centered on the center A. The radius of curvature of the swing guided surface 30 and the radius of curvature of the swing guide surface 22 are the same. The swing guided surface 30 is in sliding contact with the swing guide surface 22 from the inside. The shaft insertion hole 31 penetrates the linear motion guide portion 3 in the vertical direction. The shaft insertion hole 31 has a straight tubular shape.

  The shaft 4 can reciprocate linearly with respect to the linear motion guide portion 3. The shaft 4 includes a shaft portion 40, a first flange portion 41, and a second flange portion 42. The shaft portion 40 has a round bar shape extending in the vertical direction. The shaft portion 40 is inserted through the shaft insertion hole 31. As shown in FIG. 1, the lower end of the shaft portion 40 is connected to the arm portion 911 a of the waste gate valve 911. As shown in FIG. 2, the first flange portion 41 is disposed at the upper end of the shaft portion 40. The second flange portion 42 is disposed below the first flange portion 41. The hole edge of the through hole 60 of the diaphragm 6 is sandwiched and fixed between the first flange portion 41 and the second flange portion 42. Thus, the upper end (one axial direction) of the shaft 4 is attached to the diaphragm 6, and the lower end (the other axial end) of the shaft 4 is attached to the arm portion 911a.

  The pipe 70 is connected to the through hole 511a. The pipe 70 supplies a negative pressure to the second pressure chamber 512. The plate 72 is disposed in the second pressure chamber 512. The plate 72 has a bottomed cylindrical shape that opens upward. The plate 72 includes a peripheral wall portion 720 and a bottom wall portion 721. The plate 72 is disposed on the upper side of the diaphragm 6. The spring (biasing member) 73 is a coil spring. The spring 73 is interposed between the bottom wall portion 511 of the second casing portion 51 and the bottom wall portion 721 of the plate 72. The spring 73 urges the plate 72, that is, the diaphragm 6 downward.

<Actuator movement>
Next, the movement of the actuator of this embodiment will be described. A state in which no negative pressure is supplied to the second pressure chamber 512 is referred to as a “stop state”, and a state in which negative pressure is supplied to the second pressure chamber 512 is referred to as an “activation state”.

  As shown by the dotted lines in FIGS. 1 and 2, in the stopped state, the plate 72, the diaphragm 6, and the shaft 4 are pushed down by the urging force of the spring 73. The second flange portion 42 is seated on the support surface 210 of the swing guide portion 2. The support surface 210 supports the axial force of the shaft 4, that is, the biasing force of the spring 73. The waste gate valve 911 closes the bypass passage 910. In the stopped state, the shaft 4 is disposed at the bottom dead center (the lower end position of the stroke of the shaft 4).

  As shown by a solid line in FIGS. 1 and 2, in the activated state, negative pressure is supplied from the pipe 70 to the second pressure chamber 512. For this reason, the plate 72, the diaphragm 6, and the shaft 4 are moved upward against the urging force of the spring 73 due to the pressure difference between the first pressure chamber 502 at atmospheric pressure and the second pressure chamber 512 at negative pressure. Moving. The position where the peripheral wall portion 720 contacts the bottom wall portion 511 is the top dead center of the shaft 4 (the upper end position of the stroke of the shaft 4).

  In the activated state, by controlling the negative pressure supplied from the pipe 70, the vertical position of the shaft 4, that is, the opening degree of the waste gate valve 911 (the exhaust gas flow rate in the bypass passage 910) can be adjusted. .

<Effect>
Next, the effect of the actuator of this embodiment is demonstrated. As shown in FIG. 2, the upper end (the first flange portion 41 and the second flange portion 42) of the shaft 4 is attached to a flexible diaphragm 6. The lower end of the shaft 4 is attached to the arm portion 911a. The arm portion 911a swings in a direction that intersects the vertical direction (the stroke direction of the shaft 4). In addition, at the top dead center indicated by the solid line in FIG. 1, the portion of the shaft 4 that protrudes downward from the casing 5 is longer in the vertical direction than the portion of the shaft 4 accommodated in the casing 5. For this reason, for example, the shaft 4 is likely to swing in a direction intersecting the vertical direction as indicated by two types of dotted lines in FIG.

  Here, it is assumed that the shaft 106 swings in the conventional actuator 100 shown in FIG. The guide part 104 of the actuator 100 is fixed to the boss part 103. For this reason, even if the shaft 106 swings, the guide portion 104 cannot swing following the swing. Further, the swinging cannot be absorbed by the O-ring 105 alone. Therefore, the guide part 104 and the shaft 106 are easily worn. Further, in order to absorb the swing of the shaft 106, it is necessary to increase the clearance 107 between the guide portion 104 and the shaft 106. However, if the clearance 107 is increased, the shaft 106 is more likely to rattle.

  In this respect, according to the actuator 1 of the present embodiment, as shown in FIG. 3, the shaft 4 can reciprocate linearly, that is, reciprocate linearly (vertically) with respect to the linear motion guide portion 3. . In addition, the linear guide portion 3 can swing with respect to the swing guide portion 2. For this reason, according to the actuator 1 of the present embodiment, the shaft 4 can be linearly moved and oscillated with respect to the oscillating guide portion 2. Therefore, sliding resistance can be reduced, and wear of the swing guide part 2, the linear motion guide part 3, and the shaft 4 can be suppressed. In addition, an O-ring for absorbing the oscillation is not required between the oscillation guide portion 2 and the through holes 501a and 710 (of course, an arrangement in which the O-ring is arranged is also included in the scope of the present invention). Further, since the swing of the linear motion guide portion 3 can absorb the swing of the shaft 4, the clearance C between the shaft insertion hole 31 and the shaft portion 40 can be reduced (of course, the clearance). A form with a large C is also included in the scope of rights of the present invention). For this reason, the shaft 4 is difficult to rattle.

  Further, as shown in FIG. 3, according to the actuator 1 of the present embodiment, the swing guide part 2 includes the first guide part 20 and the second guide part 21. For this reason, the linear motion guide portion 3 can be easily arranged inside the swing guide portion 2. An insulator 71 is stacked below the bottom wall portion 501. For this reason, heat transfer from the bracket 93 to the bottom wall portion 501 can be suppressed. Further, the thickness in the radial direction of the first guide portion 20 is constant. On the other hand, the radial thickness of the second guide portion 21 increases from the lower side toward the upper side. For this reason, the second guide portion 21 is higher in rigidity (particularly in the vertical direction) than the first guide portion 20. Accordingly, the support surface 210 can reliably support the axial force of the shaft 4, that is, the urging force of the spring 73, in the stop state indicated by the dotted line in FIG. 2.

<Others>
The embodiment of the actuator of the present invention has been described above. However, the embodiment is not particularly limited to the above embodiment. Various modifications and improvements that can be made by those skilled in the art are also possible.

  The first guide part 20 and the insulator 71 shown in FIG. 3 may be integrated. Similarly, the second guide portion 21 and the bottom wall portion 501 may be integrated. Further, the swing guide part 2 and the insulator 71 may be integrated. Further, the swing guide part 2 and the bottom wall part 501 may be integrated. Further, the insulator 71 may not be arranged. The shape of the outer surface of the swing guide part 2 is not particularly limited. What is necessary is just to have the rocking | fluctuation guide surface 22 inside.

  The material of the swing guide part 2, the linear motion guide part 3, the shaft 4, and the casing 5 is not particularly limited. It may be a metal, resin, ceramic or the like. When the second guide portion 21 and the second flange portion 42 are made of metal, a resin spacer may be disposed on the upper side of the support surface 210. In this way, it is possible to suppress the second flange portion 42 from coming into contact with the support surface 210 at the bottom dead center indicated by a dotted line in FIG. That is, the occurrence of metal touch can be suppressed.

  The drive mechanism of the shaft 4 of the actuator 1 is not particularly limited. The shaft 4 may be moved by a motor or a solenoid. In particular, the actuator 1 provided with the diaphragm 6 essentially swings the shaft 4 because the diaphragm 6 is fixed to the casing 5 only through the outer peripheral edge, or because the diaphragm 6 itself is flexible. It's easy to do. For this reason, the actuator of the present invention is suitable to be embodied as the actuator 1 including the diaphragm 6.

  The drive target of the actuator 1 may not be the waste gate valve 911. For example, a throttle valve may be used. The type of valve is not particularly limited. A poppet valve, a butterfly valve, or the like may be used. The extending direction (axial direction) of the shaft 4 is not particularly limited. For example, it may be a vertical direction, a horizontal direction, a vertical direction, and a direction intersecting the horizontal direction.

  1: Actuator, 2: Swing guide part, 3: Linear motion guide part, 4: Shaft, 5: Casing, 6: Diaphragm, 20: First guide part, 21: Second guide part, 22: Swing guide surface , 30: swing guided surface, 31: shaft insertion hole, 40: shaft portion, 41: first flange portion, 42: second flange portion, 50: first casing portion, 51: second casing portion, 60: Through hole, 70: piping, 71: insulator, 72: plate, 73: spring, 90: intake system, 91: exhaust system, 92: turbocharger, 93: bracket, 210: support surface, 500: peripheral wall, 501: Bottom wall portion, 501a: through-hole, 502: first pressure chamber, 510: peripheral wall portion, 511: bottom wall portion, 511a: through-hole, 512: second pressure chamber, 710: through-hole, 720: peripheral wall portion, 721 : Bottom wall 910: Bypass passage, 911: waste gate valve, 911a: arm portion, A: center, C: Clearance

Claims (3)

A swing guide portion having a partially back spherical swing guide surface;
A linear guide portion that has a partially spherical swing guided surface that is in sliding contact with the swing guide surface from the inside, and a straight tubular shaft insertion hole, and is swingable with respect to the swing guide portion; ,
A shaft inserted through the shaft insertion hole and capable of reciprocating linearly with respect to the linear motion guide portion;
An actuator comprising: A casing having a bottom wall;
A diaphragm that partitions the inside of the casing into a first pressure chamber on the bottom wall side and a second pressure chamber, and is elastically deformable by a pressure difference between the first pressure chamber and the second pressure chamber;
With
At least a part of the swing guide part and the linear motion guide part is disposed on the bottom wall part,
The actuator according to claim 1, wherein the shaft is connected to the diaphragm via the shaft insertion hole and the first pressure chamber. A casing having a bottom wall;
An insulator laminated outside the bottom wall,
With
The swing guide portion has a first guide portion disposed on the insulator and a support surface disposed on the bottom wall portion and supporting the axial force of the shaft, and has a higher rigidity than the first guide portion. The actuator according to claim 1, further comprising two guide portions.

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