JP6673747B2 - Double eccentric valve and method of manufacturing the same - Google Patents

Description

  According to the present invention, an axis of a rotary shaft, which is a center of rotation of a valve element, is arranged away from a sealing surface of the valve element (primary eccentricity) and is arranged away from an axis of the valve element (secondary eccentricity). The present invention relates to a heavy eccentric valve and a manufacturing method thereof.

  Conventionally, as this kind of technology, for example, a butterfly type double eccentric valve described in Patent Document 1 below is known. The double eccentric valve holds a valve body (housing) having a flow path, a valve seat provided in the flow path and having a seat surface, a valve body having a sealing surface in contact with the seat surface, and a valve body. , A valve shaft (rotating shaft) rotatably provided in the housing. Here, the relationship between the valve body and the rotating shaft is such that the axis of the rotating shaft is disposed away from the sealing surface of the valve body in a direction along the axis of the valve body, and is perpendicular to the coaxial line from the axis of the valve body. To be spaced apart in the direction.

JP-A-10-299907

  By the way, in the double eccentric valve described in Patent Document 1, in a fully closed state in which the valve body is seated on the valve seat of the housing, the rotating shaft is so arranged that the sealing surface is in close contact with the seat surface so that no gap is formed between the two. Must be assembled to the valve body. However, a gap may be formed between the seal surface and the seat surface in the fully closed state depending on assembly variations between the valve body, the valve seat, and the rotary shaft, and fluid may leak from the gap.

  The present invention has been made in view of the above circumstances, and an object of the present invention is to eliminate a positional shift due to a variation in assembly between a valve seat and a valve body, and to displace a valve seat and a valve body in a fully closed state. It is an object of the present invention to provide a double eccentric valve and a method for manufacturing the double eccentric valve which can ensure a sealing property between them.

In order to achieve the above object, an invention according to claim 1 is a valve seat including a valve hole and an annular seat surface formed in the valve hole, and an annular seal formed in a disc shape and corresponding to the seat surface. A valve body having a surface formed on the outer periphery, a housing including a flow path through which a fluid flows, a valve seat and a valve body being disposed in the flow path, and rotatably provided on the housing to rotate the valve body The rotating shaft and the axis of the rotating shaft are arranged away from the sealing surface of the valve body, and are arranged away from the axis of the valve body, and the rotating shaft has the valve body supported on its axis. The valve body includes a protrusion that projects in the direction of the axis of the valve body on the side opposite to the side facing the valve seat and is attached to the valve body support section. By rotating the valve element about the axis of the rotating shaft, the fully closed position where the sealing surface contacts the seat surface is Sealing surface with the movable in double eccentric valve between the farthest fully open position from the surface, the flow path, in a state where the valve body is disposed in the fully closed position, enclosing the sealing surface of the valve body includes a portion faces has an opening with a portion thereof extends with a constant inner diameter, the valve seat from the opening is insertable formed Rutotomoni is pressed can be formed toward the valve seat to the valve body, the valve seat Means that the outer periphery of the valve seat is joined to the inner wall of the flow path on the side opposite to the side facing the valve element.

  According to the configuration of the present invention, the rotary shaft is supported by the housing, and the valve body is assembled to the valve body support portion at the protrusion, and the flow path is on the side opposite to the side where the valve body is arranged. By inserting the valve seat from the opening into the flow path, the valve body can be seated on the valve seat. In this seated state, by pressing the valve body toward the valve seat and pressing the valve seat toward the valve body, it is possible to bring the sealing surface of the valve body into close contact with the seat surface of the valve seat. . Further, in this close contact state, the outer periphery of the valve seat can be joined to the inner wall of the flow passage through the opening. Such assembling is allowed.

  In order to achieve the above object, an invention according to claim 2 is a valve seat including a valve hole and an annular seat surface formed in the valve hole, and an annular seal formed in a disk shape and corresponding to the seat surface. A valve body having a surface formed on the outer periphery, a housing including a flow path through which a fluid flows, a valve seat and a valve body being disposed in the flow path, and rotatably provided on the housing to rotate the valve body The rotating shaft and the axis of the rotating shaft are arranged away from the sealing surface of the valve body, and are arranged away from the axis of the valve body, and the rotating shaft has the valve body supported on its axis. The valve body includes a protrusion that projects in the direction of the axis of the valve body on the side opposite to the side facing the valve seat and is attached to the valve body support section. By rotating the valve element about the axis of the rotating shaft, the fully closed position where the sealing surface contacts the seat surface is In a method of manufacturing a double eccentric valve configured to be movable between a fully open position farthest from a surface, a rotary shaft is supported by a housing, and a valve body is assembled to a valve body support portion with a projection to form a flow path. And a step of inserting a valve seat into the flow path from the opening opposite to the side where the valve element is disposed, and seating the valve element assembled to the valve element support portion on the valve seat; A step of joining the outer periphery of the valve seat and the inner wall of the flow passage while pressing the seat toward the valve body.

  According to the configuration of the invention described above, in the first step, the rotary shaft is supported by the housing, and the valve body is assembled to the valve body support portion by the projection and arranged in the flow path. Thereby, the valve body supported by the rotating shaft is arranged in the flow passage in the housing. In the next step, the valve seat is inserted into the flow path, and the valve body assembled to the valve body support is seated on the valve seat. Thereby, the valve seat and the valve element are positioned in the fully closed state. In the next step, the outer periphery of the valve seat and the inner wall of the flow path are joined while pressing the valve seat toward the valve body. At this time, the sealing surface of the valve body and the seat surface of the valve seat come into close contact with each other by pressing the valve seat toward the valve body. Further, by the joining of the valve seat to the flow path, the close contact state between the seal surface and the seat surface is maintained.

  In order to achieve the above object, according to a third aspect of the present invention, in the second aspect, the outer periphery of the valve seat and the inner wall of the flow passage are joined while pressing the valve seat toward the valve body. In the process, it is intended to further press the valve body toward the valve seat.

  According to the configuration of the invention described above, in addition to the operation of the invention described in claim 2, the valve body is pressed toward the valve seat and the valve seat is pressed toward the valve body. The seat surface of the seat is in close contact with the seat.

  In order to achieve the above object, the invention according to claim 4 is the invention according to claim 2 or 3, wherein the outer periphery of the valve seat and the inner wall of the flow passage are pressed while pressing the valve seat toward the valve body. In the joining step, the rotating shaft is further pressed toward the valve seat.

  According to the configuration of the above invention, in addition to the operation of the invention according to claim 2 or 3, the rotary shaft is further pressed toward the valve seat, so that the mounting back of the rotary shaft is held down and the valve seat and the valve are pressed. Close contact with body.

  In order to achieve the above object, the invention according to claim 5 is the invention according to any one of claims 2 to 4, wherein the valve seat is pressed toward the valve body while the outer periphery of the valve seat and the flow path are formed. At the same time as the step of joining the inner wall, the step of joining the projection and the valve body support while pressing the valve seat toward the valve body is further provided.

  According to the configuration of the present invention, in addition to the operation of the invention according to any one of claims 2 to 4, in this step, the projection and the valve body support are joined while pressing the valve seat toward the valve body. . At this time, since the valve seat is pressed toward the valve body, the projection and the valve body support are in contact with each other and positioned. Further, the positioning of the projection and the valve body support portion is maintained by joining the projection to the valve body support portion.

  In order to achieve the above object, according to a sixth aspect of the present invention, in the third aspect of the invention, the projection is formed by pressing the valve body toward the valve seat and pressing the valve seat toward the valve body. In the step of joining the valve body support portion with the valve body support portion, the valve body support portion is a pin formed at the tip of the rotating shaft, and the projection has a pin hole for inserting the pin, and the pin hole is formed. While pressing the valve body toward the valve seat with a force greater than the force pressing the valve seat toward the valve body, the inner peripheral surface of the pin hole and the outer peripheral surface of the pin are aligned with the axis of the pin. It is intended to join along the direction.

  According to the configuration of the present invention, in addition to the operation of the invention described in claim 3, the valve body is opened with a force greater than the force pressing the valve seat toward the valve body with the pin inserted into the pin hole. While pressing toward the seat, the inner peripheral surface of the pin hole and the outer peripheral surface of the pin are joined along the axial direction of the pin. Therefore, the pin and the pin hole are joined with the inner peripheral surface of the pin hole pressed against the outer peripheral surface of the pin.

  According to the first aspect of the present invention, it is possible to eliminate the positional deviation due to the assembly variation between the valve seat and the valve body by adjusting the assembly, and the position of the valve seat and the valve body in the fully closed state can be eliminated. The sealing property between them can be ensured.

  According to the second aspect of the present invention, it is possible to eliminate a positional deviation due to a variation in assembling between the valve seat and the valve body, and secure a sealing property between the valve seat and the valve body in a fully closed state. can do.

  According to the third aspect of the invention, in addition to the effect of the second aspect, the sealing performance between the valve seat and the valve element in the fully closed state can be improved.

  According to the invention described in claim 4, in addition to the effect of the invention described in claim 2 or 3, it is possible to prevent a relative displacement between the valve seat and the valve body due to the mounting backlash of the rotating shaft. it can.

  According to the fifth aspect of the present invention, in addition to the effects of the second to fourth aspects, the valve body and the rotating shaft can be removed in a state in which the positional displacement due to assembly variation between the valve seat and the valve body has been eliminated. And can be assembled.

  According to the invention described in claim 6, in addition to the effect of the invention described in claim 3, it is possible to firmly join the projection of the valve body and the pin of the rotating shaft.

FIG. 2 is a perspective view showing an EGR valve according to the first embodiment. FIG. 3 is a perspective view showing a valve portion in a fully closed state according to the first embodiment with a part of the valve portion cut away. FIG. 3 is a perspective view showing a valve portion in a fully opened state according to the first embodiment with a part of the valve portion cut away. FIG. 2 is a plan sectional view showing the EGR valve in a fully closed state according to the first embodiment. FIG. 4 is a cross-sectional view showing a relationship between a small-diameter flow path, a valve seat, a valve body, and a rotation shaft in a fully closed state according to the first embodiment. 5 is a flowchart illustrating a procedure of a manufacturing method according to the first embodiment. FIG. 6 is a cross-sectional view showing one step according to the procedure of the manufacturing method according to the first embodiment. FIG. 6 is a cross-sectional view showing one step according to the procedure of the manufacturing method according to the first embodiment. FIG. 6 is a cross-sectional view showing one step according to the procedure of the manufacturing method according to the first embodiment. 9 is a flowchart illustrating a procedure of a manufacturing method according to the second embodiment. FIG. 13 is a cross-sectional view showing one step related to the procedure of the manufacturing method according to the second embodiment. FIG. 9 is a cross-sectional view showing one step of a manufacturing method according to another embodiment.

<First embodiment>
Hereinafter, a first embodiment in which the double eccentric valve of the present invention is embodied as an exhaust gas recirculation valve (EGR valve) will be described in detail with reference to the drawings.

  FIG. 1 is a perspective view of an EGR valve 10 according to this embodiment. In a gasoline engine system mounted on an automobile, an exhaust gas recirculation passage (EGR passage) is provided in which a part of exhaust gas discharged from the engine to an exhaust passage flows to an intake passage as exhaust gas recirculation gas (EGR gas) and is returned to each cylinder. Can be The EGR valve 10 is provided for adjusting the flow rate of EGR gas in the EGR passage. In this embodiment, the EGR valve 10 is constituted by a motor-operated valve having a variable opening. It is desirable that the EGR valve 10 has characteristics of a large flow rate, a high response, and a high resolution. Therefore, in this embodiment, as a structure of the EGR valve 10, for example, a configuration of a “double eccentric valve” described in Japanese Patent No. 5759646 is adopted as a basic configuration. This double eccentric valve is configured for large flow control.

  That is, as shown in FIG. 1, the EGR valve 10 includes a valve section 31 formed of a double eccentric valve, a motor section 32 having a built-in motor 42 (see FIG. 4), and a reduction mechanism 43 (see FIG. 4). And a speed reduction mechanism section 33 having a built-in mechanism. The valve section 31 includes a pipe section 37 having a flow path 36 through which the EGR gas flows. In the flow path 36, a valve seat 38, a valve body 39, and a tip of a rotary shaft 40 are arranged. The rotational force of a motor 42 (see FIG. 4) is transmitted to the rotating shaft 40 via a speed reduction mechanism 43 (see FIG. 4).

  FIG. 2 is a partially cutaway perspective view of the valve portion 31 in a fully closed state in which the valve body 39 is disposed at a fully closed position where the valve body 39 is seated on the valve seat 38. FIG. 3 is a partially cutaway perspective view of the valve portion 31 in a fully opened state where the valve body 39 is farthest from the valve seat 38. As shown in FIGS. 2 and 3, the flow path 36 includes a large-diameter flow path 36A and a small-diameter flow path 36B, and the valve seat 38 is inserted into the small-diameter flow path 36B and fixed by welding. The large-diameter passage 36A extends upward and opens at a constant inner diameter, and the small-diameter passage 36B extends downward and opens at a constant inner diameter. The valve seat 38 has an annular shape and has a valve hole 38a at the center. An annular seat surface 38b is formed at the edge of the valve hole 38a. The valve body 39 has a disk shape, and an annular seal surface 39a corresponding to the seat surface 38b is formed on the outer periphery thereof. The valve body 39 is fixed to the tip of the rotating shaft 40 and rotates integrally with the rotating shaft 40. 2 and 3, the large-diameter flow passage 36A above the valve seat 38 indicates the upstream side of the flow of the EGR gas, and the small-diameter flow passage 36B below the valve seat 38 indicates the downstream side of the EGR gas flow. In this embodiment, the large-diameter passage 36A is an “exhaust side” that communicates with the engine exhaust passage via an EGR passage, and the small-diameter passage 36B is an “intake side” that communicates with the engine intake passage via an EGR passage. It is.

  FIG. 4 is a plan sectional view of the EGR valve 10 in a fully closed state. As shown in FIG. 4, the EGR valve 10 includes a body 41, a motor 42, a reduction mechanism 43, and a return mechanism 44 as main components in addition to the valve seat 38, the valve body 39, and the rotating shaft 40. The body 41 includes an aluminum valve housing 45 including a flow path 36 and a pipe portion 37, and a synthetic resin end frame 46 for closing an open end of the housing 45. The rotation shaft 40 and the valve body 39 are provided in the valve housing 45. That is, the rotating shaft 40 includes a columnar pin 40a at the tip of which the valve body 39 is supported. The pin 40a corresponds to an example of the valve body support of the present invention. The rotating shaft 40 has a free end at the tip where the pin 40a is located, and the tip is disposed in the large-diameter flow path 36A together with the valve body 39. In this embodiment, the valve element 39 and the distal end of the rotary shaft 40 are arranged in the large-diameter flow path 36 </ b> A, and the valve element 39 is provided so as to be seated on the valve seat 38. The rotation shaft 40 has a base end 40b on the side opposite to the pin 40a, and is supported by the valve housing 45 at the base end 40b. In addition, the base end portion 40b of the rotating shaft 40 is rotatably supported by the valve housing 45 via two bearings arranged apart from each other, that is, a first bearing 47 and a second bearing 48. A rubber seal 61 is provided between the rotary shaft 40 and the valve housing 45 adjacent to the second bearing 48. The first bearing 47 and the second bearing 48 are each configured by a ball bearing. The valve body 39 includes a protrusion 39b projecting upward (on the side of the large-diameter flow path 36A) on the axis L2 (see FIG. 5), and a cylindrical pin hole 39c is formed in the protrusion 39b. The valve body 39 is fixed to the rotating shaft 40 by inserting and welding a pin 40a into the pin hole 39c.

  4, the end frame 46 is fixed to the valve housing 45 by a plurality of clips (not shown). Inside the end frame 46, an opening sensor 49 is provided corresponding to the base end of the rotating shaft 40 and detects the opening of the valve body 39 (valve opening). Further, a main gear 51 is fixed to the base end portion 40 b of the rotating shaft 40. A return spring 50 is provided between the main gear 51 and the valve housing 45 to bias the valve body 39 in the valve closing direction. A concave portion 51a is formed on the back side of the main gear 51, and a magnet 56 is housed in the concave portion 51a. The magnet 56 is pressed and fixed by a pressing plate 57 from above. Therefore, when the main gear 51 rotates integrally with the valve body 39 and the rotating shaft 40, the magnetic field of the magnet 56 changes, and the change in the magnetic field is detected by the opening sensor 49 as the valve opening. I have.

  As shown in FIG. 4, the motor 42 is housed in a housing recess 45 a formed in the valve housing 45. The motor 42 is fixed to the valve housing 45 via the retaining plate 58 and the leaf spring 59 at the accommodation recess 45a. The motor 42 is drivingly connected to the rotating shaft 40 via a speed reduction mechanism 43 to open and close the valve body 39. That is, a motor gear 53 fixed on an output shaft (not shown) of the motor 42 is drivingly connected to the main gear 51 via the intermediate gear 52. The intermediate gear 52 is constituted by a two-stage gear including a large-diameter gear 52a and a small-diameter gear 52b. The intermediate gear 52 is rotatably supported by the valve housing 45 via a pin shaft 54. The motor gear 53 is connected to the large diameter gear 52a, and the main gear 51 is connected to the small diameter gear 52b. In this embodiment, the speed reduction mechanism 43 is constituted by the gears 51 to 53. The main gear 51 and the intermediate gear 52 are formed of a resin material for weight reduction. A rubber gasket 60 is provided at a joint between the valve housing 45 and the end frame 46. The gasket 60 seals the interior of the motor section 32 and the reduction mechanism section 33 from the atmosphere.

  Accordingly, as shown in FIG. 2, the motor 42 operates and the motor gear 53 rotates from the fully closed state, and the rotation is reduced by the intermediate gear 52 and transmitted to the main gear 51. Thereby, the rotating shaft 40 and the valve body 39 are rotated against the urging force of the return spring 50, and the flow path 36 is opened. That is, the valve body 39 is opened. When closing the valve body 39, the motor 42 reverses the motor gear 53. In order to maintain the valve body 39 at a certain opening, a rotational force is generated by the motor 42, and the rotational force is transmitted to the rotary shaft 40 via the motor gear 53, the intermediate gear 52, and the main gear 51 as a retaining force. This holding force is balanced with the urging force of the return spring 50, so that the valve body 39 is held at a certain opening.

  FIG. 5 is a sectional view showing the relationship among the flow path 36, the valve seat 38, the valve element 39, and the rotating shaft 40 in the fully closed state. As shown in FIG. 5, the small-diameter flow path 36B has an opening 36b on the side opposite to the side on which the valve body 39 is arranged, and the valve seat 38 is formed so that the valve seat 38 can be inserted through the opening 36b. The outer periphery of the valve seat 38 is joined to the inner wall of the small-diameter flow path 36B on the side opposite to the side facing the valve body 39. In FIG. 5, a portion with a black circle P1 indicates a joining portion between the valve seat 38 and the small-diameter flow passage 36B. In FIG. 5, the axis L1 of the rotating shaft 40 is disposed upwardly from the sealing surface 39a of the valve body 39 by a first distance X, and extends in the radial direction of the valve body 39 from the axis L2 of the valve body 39. 2 apart by a distance Y. Here, the pin 40a of the rotating shaft 40 is disposed on the axis L1 of the rotating shaft 40. Therefore, in this embodiment, the pin 40a is disposed on the same axis L1 as the rotary shaft 40, and the axis L1 which is the center of rotation of the valve body 39 is shifted by the first distance X from the seal surface 39a of the valve body 39. It is arranged away (primary eccentricity) away from the axis L2 of the valve element 39 by a second distance Y (secondary eccentricity). The valve body 39 has a first side portion 39A (hatched in FIG. 5) bounded by an imaginary plane V1 extending from the axis L1 of the rotary shaft 40 to the direction in which the axis L2 of the valve body 39 extends. 5) and a second side portion 39B (a portion not shaded in FIG. 5). When the valve body 39 rotates from the fully closed state in the valve opening direction (clockwise direction in FIG. 5) F1 about the axis L1 of the rotating shaft 40, the first side portion 39A is connected to the small-diameter flow path 36B. , And the second side 39B rotates toward the large-diameter flow path 36A. When the valve body 39 is closed from the open state to the fully closed state, the valve body 39 rotates in the valve closing direction (counterclockwise in FIG. 5) opposite to the valve opening direction F1. In this embodiment, the configuration of the seal surface 39a of the valve body 39 and the seat surface 38b of the valve seat 38 and the relationship between the two surfaces 39a and 38b are the same as those described in Japanese Patent No. 5759646.

  Next, a method of manufacturing the double eccentric valve portion of the EGR valve 10 will be described below. FIG. 6 is a flowchart showing the procedure of the manufacturing method. 7 to 9 show cross-sectional views of each step related to the procedure. The flowchart of FIG. 6 shows an assembling procedure of the valve housing 45 including the flow path 36, the valve seat 38, the valve body 39, and the rotating shaft 40.

  First, in the "step of assembling the valve body to the rotary shaft" shown in (1) of FIG. 6, as shown in FIG. 7, the rotary shaft 40 is supported by the valve housing 45, and the valve body 39 is connected to the projection 39b. And is disposed in the flow path 36 by assembling with the pin 40a. At this time, the pin 40a of the rotating shaft 40 is inserted into the pin hole 39c of the projection 39b.

  Next, in the “step of seating the valve body on the valve seat” shown in (2) of FIG. 6, as shown in FIG. 8, the valve seat 38 is opened through the opening 36b opposite to the side where the valve body 39 is arranged. Is inserted into the small-diameter flow path 36B, and the valve body 39 attached to the pin 40a is seated on the valve seat 38.

  Next, in the “step of joining the valve seat and the inner wall of the flow path while pressing the valve body and the valve seat” shown in (3) of FIG. 6, the valve body 39 is moved to the valve seat 38 as shown in FIG. The outer periphery of the valve seat 38 and the inner wall of the small-diameter flow path 36B are joined while pressing the valve seat 38 toward the valve body 39 with another jig 72 while pressing the valve seat 38 toward the valve body 39. At this time, a force FB pressing the valve body 39 toward the valve seat 38 by the jig 71 is larger than a force FA pressing the valve seat 38 toward the valve body 39 by another jig 72. Set. As an example of the joining method, laser welding using a laser welding device 73 can be adopted. A joining point (welding point) is shown by a black circle P1 in FIG. By such a series of steps, an assembled state as shown in FIG. 5 can be obtained.

  According to the method of manufacturing the double eccentric valve (EGR valve 10) in this embodiment described above, in the first step, the rotating shaft 40 is supported by the valve housing 45, and the valve body 39 is held by the projection 39b. It is assembled to the pin 40a of the rotating shaft 40 and arranged in the large-diameter flow path 36A. As a result, the valve body 39 supported by the rotary shaft 40 in the valve housing 45 is disposed in the large-diameter flow path 36A. In the next step, the valve seat 38 is inserted into the small-diameter flow path 36B, and the valve body 39 attached to the pin 40a is seated on the valve seat 38. Thereby, the valve seat 38 and the valve element are positioned in the fully closed state. In the next step, the outer periphery of the valve seat 38 and the inner wall of the small-diameter passage 36B are joined while pressing the valve body 39 toward the valve seat 38 and pressing the valve seat 38 toward the valve body 39. At this time, the valve body 39 is pressed toward the valve seat 38 and the valve seat 38 is pressed toward the valve body 39, so that the sealing surface 39a of the valve body 39 and the seat surface 38b of the valve seat 38 are relative to each other. The displacement is eliminated, and the sealing surface 39a and the sheet surface 38b are in close contact with each other. Further, by the joining of the valve seat 38 to the small-diameter flow path 36B, the close contact between the seal surface 39a and the seat surface 38b is maintained. For this reason, even if there is a positional deviation between the valve seat 38 and the valve body 39 due to assembly variation, the positional deviation can be eliminated, and the position of the valve seat 38 and the valve body 39 in the fully closed state can be reduced. The sealing property between them can be ensured, and the sealing property can be improved. As a result, EGR gas leakage between the valve seat 38 and the valve body 39 in the fully closed state can be prevented.

  Further, according to the manufacturing method of this embodiment, the force FB for pressing the valve body 39 toward the valve seat 38 is greater than the force FA for pressing the valve seat 38 toward the valve body 39. The valve seat 38 is positioned with respect to the valve body 39 while the position 39 is positioned on the rotation shaft 40. For this reason, after the positioning of the valve seat 38 with respect to the valve body 39, the displacement of the valve body 39 due to the assembly variation between the valve body 39 and the rotating shaft 40 can be prevented.

  In addition, according to the configuration of the double eccentric valve (EGR valve 10) of this embodiment, the small-diameter flow path 36B has the opening 36b on the side opposite to the side where the valve element 39 is arranged, and the opening 36b The valve seat 38 is formed so that it can be inserted. The outer periphery of the valve seat 38 is joined to the inner wall of the small-diameter flow passage 36B on the side opposite to the side facing the valve body 39. Accordingly, in a state in which the rotary shaft 40 is supported by the valve housing 45 and the valve body 39 is assembled to the pin 40a of the rotary shaft 40 at the projection 39b, the valve passes from the opening 36b of the small-diameter flow passage 36B to the small-diameter flow passage 36B. By inserting the seat 38, the valve body 39 can be seated on the valve seat 38. In this seated state, the valve body 39 is pressed toward the valve seat 38 and the valve seat 38 is pressed toward the valve body 39, so that the sealing surface 39a of the valve body 39 is seated on the seat surface 38b of the valve seat 38. It is possible to make it adhere to. Further, in this close contact state, the outer periphery of the valve seat 38 can be joined to the inner wall of the small-diameter flow passage 36B through the opening 36b. Such assembling (manufacturing method) is allowed. For this reason, even if there is a positional deviation between the valve seat 38 and the valve body 39 due to assembly variations, the positional deviation can be eliminated by adjustment at the time of assembly, and the valve seat 38 can be completely closed. And the valve body 39 can secure the sealing performance.

<Second embodiment>
Next, a second embodiment in which the double eccentric valve of the present invention is embodied as an exhaust gas recirculation valve (EGR valve) will be described in detail with reference to the drawings.

  This embodiment differs from the first embodiment in the method of manufacturing the double eccentric valve portion in the EGR valve 10. Hereinafter, the different points will be mainly described. FIG. 10 is a flowchart showing the procedure of the manufacturing method. FIG. 11 is a cross-sectional view showing one step in the procedure of the manufacturing method.

  In this embodiment, in the procedure of assembling the valve housing 45 including the flow path 36, the valve seat 38, the valve body 39, and the rotating shaft 40, the contents of the step shown in FIG. (3) is different from the contents of the step. Further, the configuration is different from that of the first embodiment in that a step (4) is added after the step (3) in FIG.

  That is, in the “step of joining the valve seat and the inner wall of the flow passage while pressing the valve body and the rotating shaft and the valve seat” shown in (3) of FIG. 10, the valve body 39 is moved to the valve seat as shown in FIG. The outer periphery of the valve seat 38 and the inner wall of the small-diameter flow path 36B are joined while pressing the valve seat 38 toward the valve body 39 with another jig 72 while pressing the valve seat 38 toward the valve body 39 with the jig 71. At this time, the tip of the rotating shaft 40 arranged in the large-diameter flow path 36A is pressed by another jig 74. Also, the force FB pressed by the jig 71 and another jig 74 is set to be larger than the force FA pressed by another jig 72. As an example of the joining method, laser welding using a laser welding device 73 can be adopted. A joining point (welding point) is shown by a black circle P1 in FIG.

  In the “step of joining the projection of the valve body and the pin while pressing the valve body and the valve seat” shown in (4) of FIG. 10, the valve body 39 is turned to the valve seat 38 as shown in FIG. 11. The projection 39b of the valve body 39 and the pin 40a of the rotary shaft 40 are joined while pressing the valve seat 38 toward the valve body 39 with another jig 72 while pressing the same with the jig 71. As an example of this joining method, laser welding using a laser welding device can be adopted. The joining point (welding point) is shown by a black circle P2 in FIG.

  Here, the bonding conditions in the step shown in FIG. 10 (4) are as follows. That is, in a state where the pin 40a is inserted into the pin hole 39c, the valve body 39 is pressed with a force FB larger than the force FA for pressing the valve seat 38 toward the valve body 39, similarly to the step shown in FIG. Is pressed toward the valve seat 38, and the inner peripheral surface of the pin hole 39c and the outer peripheral surface of the pin 40a are joined along the direction of the axis L1 of the pin 40a.

  According to the manufacturing method of this embodiment described above, in the step shown in FIG. 10C, the valve body 39 is pressed toward the valve seat 38 and the rotary shaft 40 is pressed toward the valve seat 38. The valve seat 38 and the valve body 39 come into close contact with each other in a state where the mounting play of the rotating shaft 40 is pressed. For this reason, even if there is an attachment play on the rotating shaft 40, it is possible to prevent a relative displacement between the valve seat 38 and the valve body 39 due to the attachment play.

  According to the manufacturing method of this embodiment, in the step shown in FIG. 10D, the valve body 39 is pressed toward the valve seat 38 and the valve seat 38 is pressed toward the valve body 39 while projecting. The part 39b and the pin 40a are joined. At this time, since the valve body 39 is pressed toward the valve seat 38 and the valve seat 38 is pressed toward the valve body 39, the relative position between the projection 39b of the valve body 39 and the pin 40a of the rotary shaft 40 is set. The displacement is eliminated, and the protrusion 39b and the pin 40a come into contact with each other and are positioned. In addition, the positioning of the projection 39b and the pin 40a is maintained by joining the projection 39b to the pin 40a. For this reason, the valve body 39 and the rotating shaft 40 can be assembled in a state where the positional deviation due to the assembly variation between the valve seat 38 and the valve body 39 is eliminated. Further, even if there is a positional deviation between the valve body 39 and the rotary shaft 40 due to assembly variations, the positional deviation can be eliminated, and the position between the valve seat 38 and the valve body 39 in the fully closed state can be eliminated. Sealing property can be ensured.

  Further, in the step indicated by (4) in FIG. 10, in a state where the pin 40 a is inserted into the pin hole 39 c, the valve body 39 is pressed with a force FB larger than the force FA for pressing the valve seat 38 toward the valve body 39. While pressing toward the seat 38, the inner peripheral surface of the pin hole 39c and the outer peripheral surface of the pin 40a are joined along the direction of the axis L1 of the pin 40a. Therefore, the pin 40a and the pin hole 39c are joined along the direction of the axis L1 of the pin 40a while the inner peripheral surface of the pin hole 39c is pressed against the outer peripheral surface of the pin 40a. As a result, the projection 39b of the valve body 39 and the pin 40a of the rotating shaft 40 can be firmly joined. In this embodiment, the same operation and effect as those of the first embodiment can be obtained.

  Note that the present invention is not limited to the above embodiments, and a part of the configuration can be appropriately changed and implemented without departing from the spirit of the invention.

  (1) In the above embodiments, in the steps shown in (3) of FIG. 6 and (3) of FIG. 10, the valve body 39 is pressed toward the valve seat 38 and the valve seat 38 is directed toward the valve body 39. It was configured to be pressed. On the other hand, the valve seat 38 may be configured to be pressed toward the valve body 39 without pressing the valve body 39 toward the valve seat 38. In this case, when the valve seat 38 is pressed toward the valve body 39, the sealing surface 39a of the valve body 39 and the seat surface 38b of the valve seat 38 come into close contact with each other. For this reason, the sealing property between the valve seat 38 and the valve body 39 in the fully closed state can be ensured.

  (2) In the second embodiment, in the step shown in (4) of FIG. 10, the valve body 39 is pressed toward the valve seat 38 while the pin 40a is inserted into the pin hole 39c, and the valve seat 38 is pressed. The projection 39b and the pin 40a were joined while pressing toward the valve body 39. On the other hand, as shown in FIG. 12, in a state where the pin 40a is fitted into the concave portion 39d formed in the projection 39b, the valve seat 38 is The projection 39b and the pin 40a may be joined together while being pressed against the body 39. In this case, since the valve seat 38 is pressed toward the valve body 39, the projection 39b and the pin 40a come into contact with each other and are positioned. In addition, the positioning of the projection 39b and the pin 40a is maintained by joining the projection 39b to the pin 40a. For this reason, the valve body 39 and the rotating shaft 40 can be assembled in a state where the positional deviation due to the assembly variation between the valve seat 38 and the valve body 39 is eliminated.

  (3) In the second embodiment, after the “step of joining the valve seat and the inner wall of the flow passage while pressing the valve body and the rotating shaft and the valve seat” shown in (3) of FIG. Although the "step of joining the projection of the valve body and the pin while pressing the valve body and the valve seat" shown in 4) is provided, these two steps can be provided simultaneously.

  (4) In each of the above embodiments, laser welding is adopted as a method for joining members, but electric welding or other joining techniques can be adopted.

  (5) The shapes of the flow path 36, the valve seat 38, the valve body 39, the rotating shaft 40, and the like in the above embodiments are merely examples, and can be changed as appropriate.

  INDUSTRIAL APPLICABILITY The present invention can be used for a flow rate control valve for controlling a fluid flow rate, such as an EGR valve and an electronic throttle device.

10 EGR valve 36 Flow path 36A Upstream flow path 36B Downstream flow path 36b Opening 38 Valve seat 38a Valve hole 38b Seat surface 39 Valve element 39a Seal surface 39b Projection 39c Pin hole 39A First side portion 39B Second side Part 40 Rotating shaft 40a Pin (valve support part)
45 Valve housing 71 Jig 72 Separate jig 73 Laser welding device

Claims (6)

A valve seat including a valve hole and an annular seat surface formed in the valve hole,
A valve body having a disc shape and an annular sealing surface corresponding to the seat surface formed on the outer periphery;
A housing including a flow path through which the fluid flows,
The valve seat and the valve element are arranged in the flow path;
A rotation shaft rotatably provided in the housing to rotate the valve body,
The axis of the rotating shaft is arranged away from the sealing surface of the valve body, and is arranged away from the axis of the valve body;
The rotation shaft includes a valve body support portion on which the valve body is supported,
The valve element projects in a direction of the axis of the valve element on a side opposite to a side facing the valve seat,
Including a projection attached to the valve body support portion, by rotating the valve body about the axis of the rotation shaft, the fully closed position where the sealing surface contacts the seat surface and In a double eccentric valve configured to be movable between a fully open position farthest from a seat surface,
The flow path is in a state in which the valve body is disposed in the fully closed position, wherein said portion of the sealing surface is oriented with enclosing said sealing surface of said valve body, an opening with a portion thereof extends with a constant inner diameter has been formed to be inserted the valve seat from the opening Rutotomoni, formed the valve seat so as to be pressed toward the valve body,
The double eccentric valve, wherein the valve seat has an outer periphery joined to an inner wall of the flow passage on a side opposite to a side facing the valve body. A valve seat including a valve hole and an annular seat surface formed in the valve hole,
A valve body having a disc shape and an annular sealing surface corresponding to the seat surface formed on the outer periphery;
A housing including a flow path through which the fluid flows,
The valve seat and the valve element are arranged in the flow path;
A rotation shaft rotatably provided in the housing to rotate the valve body,
The axis of the rotating shaft is arranged away from the sealing surface of the valve body, and is arranged away from the axis of the valve body;
The rotation shaft includes a valve body support portion on which the valve body is supported,
The valve element projects in a direction of the axis of the valve element on a side opposite to a side facing the valve seat,
Including a projection attached to the valve body support portion, by rotating the valve body about the axis of the rotating shaft, the fully closed position where the seal surface contacts the seat surface and In a method of manufacturing a double eccentric valve configured to be movable between a fully open position farthest from a seat surface,
A step of supporting the rotating shaft in the housing, assembling the valve body with the valve body support at the projection, and arranging the valve body in the flow path;
Inserting the valve seat into the flow path from the opening on the side opposite to the side where the valve element is arranged,
Seating the valve body assembled to the valve body support portion on the valve seat;
Joining the outer periphery of the valve seat and the inner wall of the flow passage while pressing the valve seat toward the valve body.   In the step of joining the outer periphery of the valve seat and the inner wall of the flow path while pressing the valve seat toward the valve body, the valve body is further pressed toward the valve seat. Item 3. A method for manufacturing a double eccentric valve according to Item 2.   In the step of joining the outer periphery of the valve seat and the inner wall of the flow passage while pressing the valve seat toward the valve body, the rotating shaft is further pressed toward the valve seat. Item 4. The method for producing a double eccentric valve according to item 2 or 3.   At the same time as the step of joining the outer periphery of the valve seat and the inner wall of the flow path while pressing the valve seat toward the valve body, the protrusion and the protrusion while pressing the valve seat toward the valve body The method for manufacturing a double eccentric valve according to any one of claims 2 to 4, further comprising a step of joining the valve body support portion. In the step of joining the projection and the valve body support while pressing the valve body toward the valve seat and pressing the valve seat toward the valve body,
The valve body support portion is a pin formed at the tip of the rotating shaft, the protrusion has a pin hole for inserting the pin,
While the pin is inserted into the pin hole, the inner periphery of the pin hole is pressed while pressing the valve body toward the valve seat with a force larger than the force pressing the valve seat toward the valve body. The manufacturing method of the double eccentric valve according to claim 3, wherein a surface and an outer peripheral surface of the pin are joined along an axial direction of the pin.

Images