JP2024057320A - Valve mechanism - Google Patents

Abstract

[Problem] To equalize the surface pressure of a rubber seal even when a housing end face is fastened to another pipe member, and to improve the sealing performance of the rubber seal between the housing and another pipe member. [Solution] A valve device (1) includes a housing (6) including a flow path (5), a valve seat (13) provided in the flow path (5), a valve body (14) capable of seating on the valve seat (13), a valve shaft (15) provided with the valve body (14), and an actuator (16) that reciprocates the valve shaft (15). The housing (6) is provided with a housing end face (4e) to which an EGR pipe (10) is fastened via flanges (10a, 4d). The housing end face (4e) is provided with an annular step (8) immediately before an opening (7) of the flow path (5) that reduces the inner diameter of the flow path (5) below the inner diameter of the opening (7), and the step (8) divides the flow path (5) into a large diameter portion (5a) close to the opening (7) and a small diameter portion (5b) far from the opening (7). With the EGR pipe 10 fastened to the housing end surface 4e, the large diameter portion 5a is provided with a lip seal 18 between the step surface 8 and the EGR pipe 10, which contacts the step surface 8 and the EGR pipe 10. [Selected Figure] FIG.

Description

The technology disclosed in this specification relates to a valve device that adjusts the flow rate of a fluid.

Conventionally, as this type of technology, for example, the "exhaust gas recirculation control valve device" described in Patent Document 1 below is known. This device comprises a housing including a fluid flow path, a valve seat provided in the flow path, a valve body that is capable of seating on the valve seat, a valve shaft with one end of the valve body, and a drive unit for reciprocating the valve shaft. An EGR pipe (another pipe member) is fastened by a flange and multiple bolts to the end face of the housing corresponding to the inlet (opening) of the flow path. An annular packing is sandwiched between the end face of the housing and one end of the pipe member to ensure airtightness.

WO 99/20886

However, in the device described in Patent Document 1, a packing is provided between the end face of the housing fastened by the bolts and one end of the tube member, so that strong surface pressure is applied to the packing, particularly near the bolts, making it easy for the flange to warp. Here, the closer the distance between the bolts and the packing is, the greater the surface pressure applied to the packing, so the surface pressure becomes uneven in the circumferential direction of the packing, which can lead to uneven sealing of the packing.

This disclosed technology was made in consideration of the above circumstances, and its purpose is to provide a valve device that makes it possible to equalize the surface pressure around the entire circumference of the rubber seal even when the housing end face is fastened to another tubular member, thereby improving the sealing performance of the rubber seal between the housing and the other tubular member.

In order to achieve the above object, the technology described in claim 1 is a valve device including a housing including a fluid flow path, a valve seat provided in the flow path, a valve body provided so as to be able to seat on the valve seat, a valve shaft with the valve body provided at one end, and an actuator for reciprocating the valve shaft in the axial direction, in which the housing is provided with a housing end face to which another pipe member is fastened via a flange, the housing end face is provided with an opening of the flow path, an annular step surface is provided in the flow path immediately before the opening, which reduces the inner diameter of the flow path compared to the inner diameter of the opening, the flow path is divided by the step surface into a large diameter portion close to the opening and a small diameter portion far from the opening, and with the pipe member fastened to the housing end face via a flange, a rubber seal is provided in the large diameter portion between the step surface and the pipe member, which contacts the step surface and the pipe member.

According to the configuration of the above technology, another pipe member is fastened to the end face of the housing via a flange. The flow path immediately before the opening in the end face of the housing is divided by the step surface into a large diameter section close to the opening and a small diameter section far from the opening. Then, with the pipe member fastened to the end face of the housing via a flange, a rubber seal is provided in the large diameter section between the step surface and the pipe member, contacting the step surface and the pipe member. Therefore, the rubber seal is disposed in the large diameter section of the flow path and contacts the step surface and the pipe member, so that the rubber seal seals between the housing and the pipe member. In addition, the rubber seal is not compressed between the end face of the housing and the pipe member, and its entire circumference is evenly in contact with the step surface and the pipe member.

In order to achieve the above object, the technology described in claim 2 is the technology described in claim 1, in which the housing is composed of an inner housing fixed to the actuator and an outer housing including an assembly hole into which the inner housing is assembled, the flow path is formed when the inner housing is assembled to the assembly hole of the outer housing, the housing opening is provided in the outer housing, the step surface is formed by the end face of the inner housing, and the large diameter portion is formed by the inner surface and the step surface of the outer housing.

According to the configuration of the above technology, in addition to the effect of the technology described in claim 1, the housing is divided into an inner housing fixed to the actuator and an outer housing including an assembly hole into which the inner housing is assembled, and the housing is assembled as required.

To achieve the above object, the technology described in claim 3 is the technology described in claim 2, in which the rubber seal includes a ridge on its outer periphery that faces radially outward.

According to the configuration of the above technology, in addition to the effect of the technology described in claim 2, when the inner housing is assembled into the assembly hole of the outer housing, the protrusion of the rubber seal provided in the large diameter portion comes into contact with the inner surface of the outer housing, thereby sealing between the outer housing and the inner housing. Therefore, it is possible to omit a separate seal member that seals between the outer housing and the inner housing near the opening.

In order to achieve the above object, the technology described in claim 4 is the technology described in any one of claims 1 to 3, in which the rubber seal includes a first end that abuts against the step surface in the axial direction and a second end that abuts against the tube member, and is configured so that when the tube member is removed from the housing end face and the rubber seal is placed in the large diameter portion, the second end of the rubber seal is located inside the large diameter portion relative to the housing end face, and the tube member is provided with a protrusion that fits into the large diameter portion and abuts against the second end of the rubber seal when the tube member is fastened to the housing end face.

According to the configuration of the above technology, in addition to the effect of the technology described in any one of claims 1 to 3, when the rubber seal is placed in the large diameter portion, the second end of the rubber seal is located inside the large diameter portion relative to the housing end face. Therefore, before the tube member is fastened to the housing end face, the rubber seal placed in the large diameter portion is less likely to come into contact with other members.

In order to achieve the above object, the technology described in claim 5 is directed to a valve device according to any one of claims 1 to 3, in which the rubber seal is formed by a lip seal including an annular support portion and a first lip portion and a second lip portion that protrude inward from the support portion and are inclined away from each other, and in the released state of the lip seal, the tip of the first lip portion and the tip of the second lip portion are positioned so as to be located inward from both axial ends of the support portion.

According to the configuration of the above technology, in addition to the effect of the technology described in any one of claims 1 to 3, the tip of the first lip portion and the tip of the second lip portion of the lip seal are located inside the axial ends of the support portion, so that each lip portion is less likely to come into contact with other members.

To achieve the above objective, the technology described in claim 6 aims to cover the outer periphery and both ends of the support part with a metal ring material in the technology described in claim 5.

According to the configuration of the above technology, in addition to the effect of the technology described in claim 5, the outer periphery and both ends of the support part are covered with the ring material, so that the support part is protected from contact with other members.

According to the technology described in claim 1, even when the housing end face is fastened to another tubular member, the surface pressure around the entire circumference of the rubber seal can be made uniform, and the sealing performance of the rubber seal between the housing and the other tubular member can be improved.

According to the technology described in claim 2, in addition to the effect of the technology described in claim 1, for example, the shape of the outer housing can be changed in various ways as needed while the inner housing and the assembly hole are configured in a common shape.

According to the technology described in claim 3, in addition to the effect of the technology described in claim 2, the number of parts of the valve device can be reduced by the amount that a separate seal member can be omitted, which is advantageous for reducing labor and costs. Also, since a separate seal member is not provided between the outer housing and the inner housing, the press-fit resistance when assembling (inserting) the inner housing into the assembly hole 4a can be reduced, making it easier to assemble (insert) the inner housing into the assembly hole.

The technology described in claim 4 has the effect of any of the technologies described in claims 1 to 3, and can also prevent the rubber seal assembled to the housing from being scratched or soiled before another tubular member is fastened to the housing.

According to the technology described in claim 5, in addition to the effect of the technology described in any one of claims 1 to 3, it is possible to prevent scratches and dirt on each lip part of the lip seal before use.

The technology described in claim 6 has the same effect as the technology described in claim 5, and can prevent damage to the support part of the lip seal before use.

FIG. 2 is a partially cutaway front view of the valve device according to the first embodiment. 2 is an enlarged cross-sectional view showing a portion of the valve device in FIG. 1 surrounded by a dashed double-dashed line rectangle in the first embodiment; FIG. FIG. 11 is a front view showing a valve device according to a second embodiment, the view being equivalent to FIG. FIG. 6 is an enlarged cross-sectional view equivalent to FIG. 2 showing a part of the valve device according to a second embodiment. FIG. 7 is a front view similar to FIG. 3 showing a state in which the EGR pipe is removed from the housing end surface in the second embodiment. FIG. 7 is an enlarged cross-sectional view equivalent to FIG. 4 showing a state in which the EGR pipe is removed from the housing end surface in the second embodiment. 7 is an enlarged cross-sectional view equivalent to FIG. 4 showing a state in which the EGR pipe is fastened to the housing end surface from the state shown in FIG. 6 in the second embodiment; FIG. FIG. 11 is a front view showing a valve device according to a third embodiment, the view corresponding to FIG. 5 and illustrates a state in which the EGR pipe has been removed from the housing end surface in the state illustrated in FIG. 8 according to a third embodiment. FIG. 13 is a cross-sectional view showing a flange material used for a pipe flange according to a modified example of the third embodiment. FIG. 10 is a front view showing the valve device according to the fourth embodiment, which is equivalent to FIG. 8 . FIG. 13 is a cross-sectional view showing a lip seal cut in the radial direction according to a fourth embodiment. FIG. 11 is a cross-sectional view equivalent to FIG. 2 showing a state in which the lip seal is assembled to the large diameter portion of the housing according to a modified example of the fourth embodiment. FIG. 11 is a front view showing a valve device according to a fifth embodiment, which is equivalent to FIG.

Below, several embodiments in which the valve device is embodied in an EGR device will be described in detail with reference to the drawings.

First Embodiment
First, the first embodiment will be described in detail with reference to FIGS.

[Valve device configuration]
1 shows a partially cutaway front view of a valve device 1 according to this embodiment. The valve device 1 is provided in an EGR passage (not shown) connected to an intake passage in order to return a portion of exhaust gas discharged from an engine into an exhaust passage to the engine as EGR gas. The valve device 1 includes an EGR valve 2 and an EGR pipe 10 connected thereto. The EGR valve 2 is used to adjust the flow rate of EGR gas in the EGR passage. The EGR pipe 10 corresponds to an example of the "another pipe member" of the disclosed technology.

As shown in FIG. 1, the EGR valve 2 has a poppet-type valve structure and is composed of a valve assembly 3 and an outer housing 4 to which the inner housing 11 is attached. The outer housing 4 is made of a resin material. The inner housing 11 and the outer housing 4 form the housing 6 of the EGR valve 2. The valve assembly 3 includes an approximately cylindrical inner housing 11 including a flow passage 12 for EGR gas, an annular valve seat 13 provided in the flow passage 12, an approximately umbrella-shaped valve body 14 that is capable of being seated on the valve seat 13 and for opening and closing the flow passage 12, a valve shaft 15 with the valve body 14 provided at one end thereof, and an actuator 16 for reciprocating the valve shaft 15 together with the valve body 14. The inner housing 11 is fixed to the actuator 16. In this embodiment, the inner housing 11 is made of a resin material. The actuator 16 can be, for example, a DC motor.

As shown in FIG. 1, the flow passage 12 of the inner housing 11 is bent in a generally L-shape and includes an inlet 12a and an outlet 12b. In this embodiment, the inlet 12a opens at the lower end of the inner housing 11 in the axial direction, and the outlet 12b opens at the outer periphery of the inner housing 11. In this embodiment, the valve seat 13 and the valve body 14 are made of metal. The shapes of the valve seat 13 and the valve body 14 are examples. The valve seat 13 is insert molded into the inner housing 11. This EGR valve 2 adjusts the flow rate of EGR gas in the flow passage 12 by moving the valve body 14 relative to the valve seat 13 to change the opening between the valve seat 13. In this embodiment, a detailed description of the actuator 16 is omitted.

The valve shaft 15 extends downward from the actuator 16 and passes through the inner housing 11. A rubber seal member 17 is provided between the inner housing 11 and the valve shaft 15. The valve shaft 15 is arranged parallel to the axis of the valve seat 13. The valve body 14 is seated (contacted) and separated from the valve seat 13 by the valve shaft 15 reciprocating. In addition, a lip seal 18 is provided between the outer housing 4, the inner housing 11, and the EGR pipe 10 to seal between them 4, 10, and 11. In this embodiment, the valve body 14 is movably arranged below (upstream of) the valve seat 13. The lip seal 18 corresponds to an example of a "rubber seal" in this disclosed technology.

As shown in FIG. 1, in this embodiment, the outer housing 4 has a substantially cylindrical shape and includes an assembly hole 4a into which the inner housing 11 is assembled, and an inlet flow passage 4b and an outlet flow passage 4c. This EGR valve 2 is constructed by assembling the inner housing 11 of the valve assembly 3 into the assembly hole 4a of the outer housing 4. Here, when the inner housing 11 is assembled into the assembly hole 4a, the inlet flow passage 4b communicates with the inlet 12a of the inner housing 11, and the outlet flow passage 4c communicates with the outlet 12b of the inner housing 11. That is, in this embodiment, when the inner housing 11 is assembled into the assembly hole 4a of the outer housing 4, the flow passage 5 of this disclosed technology is constituted by the flow passage portion 12, the inlet flow passage 4b, and the outlet flow passage 4c.

As shown in FIG. 1, in this embodiment, a total of three rubber seal members 18, 19, 20 are provided between the inner housing 11 and the outer housing 4 near the inlet 12a and near the outlet 12b of the inner housing 11. That is, in FIG. 1, the first O-ring 19 is provided on the outer periphery of the inner housing 11 above the outlet 12b, and the second O-ring 20 is provided on the outer periphery of the inner housing 11 near the inlet 12a. Furthermore, in FIG. 1, the aforementioned lip seal 18 is provided at the lower end of the inner housing 11, between the periphery of the inlet 12a and the inner circumferential surface of the outer housing 4.

In FIG. 1, a pipe flange 10a is provided at one end of the EGR pipe 10. A valve flange 4d is provided at the lower end of the outer housing 4. The flanges 4d and 10a of the EGR valve 2 and the EGR pipe 10 are fastened by bolts 21. A housing end surface 4e is provided at the lower end of the outer housing 4, which is fastened by the bolts 21 via the pipe flange 10a.

[About lip seals]
2 is an enlarged cross-sectional view of the valve device 1 in FIG. 1, which is surrounded by a two-dot chain line rectangle S1. As shown in FIG. 1 and FIG. 2, in this embodiment, the opening 7 of the flow passage 5 is arranged on the housing end surface 4e. The inlet flow passage 4b immediately before the opening 7 is provided with an annular step surface 8 that reduces the inner diameter of the inlet flow passage 4b to be smaller than the inner diameter of the opening 7. The step surface 8 divides the flow passage 5 into a large diameter portion 5a close to the opening 7 and a small diameter portion 5b far from the opening 7. When the inner housing 11 is assembled in the assembly hole 4a of the outer housing 4 and the EGR pipe 10 is fastened to the housing end surface 4e by the bolts 21 via the pipe flange 10a, the large diameter portion 5a is provided with a lip seal 18 that contacts the step surface 8 and the end surface 10b of the EGR pipe 10 between the step surface 8 and the end surface 10b of the EGR pipe 10. In this embodiment, the opening 7 of the housing 6 is provided in the outer housing 4 , the step surface 8 is formed by the end face of the inner housing 11 , and the large diameter portion 5 a is formed by the inner peripheral surface of the outer housing 4 and the step surface 8 .

2, the lip seal 18 of this embodiment has a generally V-shaped radial cross section, and includes a support portion 18a that contacts the step surface 8 and supports the lip seal 18 on the housing 6 (inner housing 11), and a lip portion 18b that contacts the end face 10b of the EGR pipe 10 and seals between the housing 6 (inner housing 11) and the EGR pipe 10. Here, the support portion 18a corresponds to an example of the "first end" of this disclosed technology, and the lip portion 18b corresponds to an example of the "second end" of this disclosed technology.

[About the action and effect of the valve device]
According to the configuration of the valve device 1 of this embodiment described above, the EGR pipe 10 is fastened to the housing end face 4e via the pipe flange 10a. The flow path 5 immediately before the opening 7 in the housing end face 4e is divided into a large diameter portion 5a close to the opening 7 and a small diameter portion 5b far from the opening 7, with the step surface 8 as a boundary. Then, in a state in which the EGR pipe 10 is fastened to the housing end face 4e via the pipe flange 10a and the valve flange 4d with the bolts 21, a lip seal 18 is provided in the large diameter portion 5a between the step surface 8 and the EGR 10, contacting the step surface 8 and the end surface 10b of the EGR pipe 10. Therefore, the lip seal 18 is disposed in the large diameter portion 5a of the flow path 5 and contacts the step surface 8 and the end surface 10b, so that the gap between the housing 6 (outer housing 4) and the EGR pipe 10 is sealed by the lip seal 18. Furthermore, the lip seal 18 is not compressed between the housing end face 4e and the end face 10b of the EGR pipe 10, and its entire circumference is evenly in contact with the step surface 8 and the EGR pipe 10. Therefore, even if the housing end face 4e of the EGR valve 2 and the EGR pipe 10 (another tubular member) are fastened with the bolts 21, the surface pressure of the entire circumference of the lip seal 18 can be made uniform, and the sealing performance of the lip seal 18 between the housing 6 (outer housing 4) and the EGR pipe 10 can be improved.

In this embodiment, no seal member is sandwiched between the housing end face 4e and the end face 10b of the EGR pipe 10, and the lip seal 18 is disposed between the step surface 8 in the flow passage 5 and the end face 10b of the EGR pipe 10. For this reason, the valve flange 4d may warp when the bolts 21 are fastened, but even if the valve flange 4d warps, the housing end face 4e does not warp. In other words, the housing 6 (outer housing 4) can obtain a uniform surface pressure without being affected by the fastening of the bolts 21. For this reason, the valve flange 4d can be made thinner, which is advantageous for weight reduction and cost reduction.

According to the configuration of this embodiment, the housing 6 is divided into an inner housing 11 fixed to the actuator 16 and an outer housing 4 including an assembly hole 4a into which the inner housing 11 is assembled, and these are assembled as needed. Therefore, for example, the inner housing 11 and the assembly hole 4a can be configured to have a common shape, and the shape of the outer housing 4 can be changed in various ways as needed.

According to the configuration of this embodiment, the lip seal 18 is housed in the large diameter portion 5a of the flow passage 5 of the housing 6, so there is no need to sandwich a sealing member such as a gasket between the housing end face 4e and the end face 10b of the EGR pipe 10, and the sealing member can be omitted.

Second Embodiment
Next, the second embodiment will be described in detail with reference to Figures 3 to 7. In the following description, the same components as those in the first embodiment are denoted by the same reference numerals and the description will be omitted, and the following description will focus on the differences.

[About sealing materials]
This embodiment differs from the first embodiment in the configuration of the lip seal 18. Fig. 3 shows the valve device 1 of this embodiment in a front view equivalent to Fig. 1. Fig. 4 shows a part of the valve device 1 of this embodiment in an enlarged cross-sectional view equivalent to Fig. 2. As shown in Figs. 3 and 4, the lip seal 18 of this embodiment includes a convex streak 18c facing radially outward on its outer periphery in addition to the same configuration as in the first embodiment. This convex streak 18c is continuously formed along the outer periphery of the lip seal 18, and has a function of contacting the inner circumferential surface of the outer housing 4 with elastic force and sealing between the outer housing 4 and the inner housing 11. For this reason, the second O-ring 20 is omitted in this embodiment.

Figure 5 shows a front view similar to Figure 3 of this embodiment with the EGR pipe 10 removed from the housing end surface 4e. Figure 6 shows an enlarged cross-sectional view similar to Figure 4 of this embodiment with the EGR pipe 10 removed from the housing end surface 4e. In this embodiment, when the EGR pipe 10 is removed from the EGR valve 2, the tip of the lip portion 18b of the lip seal 18 attached to the large diameter portion 5a pops out from the opening 7 of the housing 6 (outer housing 4) due to recovery from compression deformation. This recovery characteristic is the same as in the first embodiment.

Figure 7 shows an enlarged cross-sectional view equivalent to Figure 4 of this embodiment in which the EGR pipe 10 is fastened to the housing end face 4e from the state shown in Figure 6. In the process of fastening the EGR pipe 10 to the housing end face 4e, the tip of the lip portion 18b of the lip seal 18 is pressed against the end face 10b of the EGR pipe 10, and is deformed from the state shown by the two-dot chain line to the state shown by the solid line. At this time, a pressing force acts on the lip portion 18b as shown by the arrow, and this force presses the ridge 18c against the inner peripheral surface of the outer housing 4. Therefore, in this embodiment, although the second O-ring 20 is omitted, the function of the second O-ring 20 can be ensured and its sealing function can be improved.

[About the action and effect of the valve device]
According to the configuration of the valve device 1 of this embodiment described above, when the inner housing 11 is assembled into the assembly hole 4a of the outer housing 4, the protruding strip 18c of the lip seal 18 provided on the large diameter portion 5a comes into contact with the inner surface of the outer housing 4, thereby sealing between the outer housing 4 and the inner housing 11. Therefore, it is possible to omit a separate seal member (e.g., the second O-ring 20 of the first embodiment) that seals between the outer housing 4 and the inner housing 11 near the opening 7. Therefore, the number of parts of the valve device 1 can be reduced by the amount that the separate seal member can be omitted, which is advantageous for reducing the number of steps and the cost. In addition, since a separate seal member is not provided between the outer housing 4 and the inner housing 11, the press-fit resistance during assembly (insertion) of the inner housing 11 into the assembly hole 4a can be reduced, making it easier to assemble (insert) the inner housing 11 into the assembly hole 4a.

In this embodiment, when the lip seal 18 is attached to the EGR valve 2, the lip portion 18b acts in the closing direction even if exhaust pressure acts on the flow passage 5. This improves the sealing function against gas leakage to the atmosphere due to exhaust pressure.

Third Embodiment
Next, a fourth embodiment will be described in detail with reference to FIGS.

[About lip seals]
This embodiment differs from the second embodiment in terms of the arrangement of the lip seal 18, etc. FIG. 8 shows a front view of the valve device 1 of this embodiment, which is equivalent to FIG. 1. FIG. 9 shows a front view of this embodiment, which is equivalent to FIG. 5, of the EGR pipe 10 removed from the housing end surface 4e from the state shown in FIG. 8. In the second embodiment, as shown in FIG. 5 and FIG. 6, when the EGR pipe 10 is removed from the housing end surface 4e, the tip of the lip portion 18b of the lip seal 18 protrudes outward from the opening 7 of the housing 6 (outer housing 4). If the EGR valve 2 is transported or stored in this state, there is a concern that the lip seal 18 may be damaged or dust may adhere to it. Therefore, in this embodiment, the following measures are taken.

That is, in this embodiment, as shown in FIG. 8, the depth T1 of the large diameter portion 5a provided near the opening 7 of the inlet 12a of the EGR valve 2 is set to be greater than the depth in each of the above embodiments. As a result, when the EGR pipe 10 is removed from the housing end face 4e and the lip seal 18 is placed in the large diameter portion 5a, the lip portion 18b is configured to be located inside the large diameter portion 5a rather than the housing end face 4e. Also, in order to bring the end face 10b of the EGR pipe 10 into contact with the lip portion 18b, the EGR pipe 10 is provided with a protrusion 10c that is fitted into the large diameter portion 5a and abuts against the lip portion 18b when the EGR pipe 10 is fastened to the housing end face 4e.

[About the action and effect of the valve device]
According to the configuration of the valve device 1 of this embodiment described above, with the lip seal 18 disposed in the large diameter portion 5a, the lip portion 18b (second end portion) of the lip seal 18 is located inside the large diameter portion 5a with respect to the housing end surface 4e. Therefore, before the EGR pipe 10 (another pipe member) is fastened to the housing end surface 4e, the lip seal 18 disposed in the large diameter portion 5a is less likely to come into contact with other members. This makes it possible to prevent the lip seal 18 assembled to the housing 6 from being scratched or soiled before the EGR pipe 10 is fastened to the housing 6.

[Modification of the third embodiment]
As a modification of this embodiment, as shown in Fig. 10, a flange material 26 having a protrusion 26a formed by pressing a metal plate material can be joined to one end of the EGR pipe 10 by welding or the like to form a pipe flange 10a. In this case, the pipe flange 10a can be made thinner. Fig. 10 shows a cross-sectional view of the flange material 26 used for the pipe flange 10a according to this modification.

Fourth Embodiment
Next, a fourth embodiment will be described in detail with reference to FIGS.

[About lip seals]
This embodiment differs from the second and third embodiments in the configuration of the lip seal 28. Fig. 11 shows a front view of the valve device 1 of this embodiment, similar to Fig. 8. Fig. 12 shows a radial cross-sectional view of the lip seal 28 of this embodiment. As shown in Fig. 11, in this embodiment, a circumferential groove 30 that continues in the inner circumferential direction is formed on the inner wall of the large diameter portion 5a of the inlet flow passage 4b of the outer housing 4, and the lip seal 28 is assembled into this circumferential groove 30.

11 and 12, the lip seal 28 includes an annular support portion 28a, and a first lip portion 28b and a second lip portion 28c that protrude inward from the support portion 28a and are inclined away from each other. These portions 28a to 28c are integrally formed from a rubber material. The outer periphery and both ends of the support portion 28a are covered by a metal ring member 28d. When the lip seal 28 is in a released state, that is, when the lip seal 28 is in a released state without contacting other members, the tip of the first lip portion 28b and the tip of the second lip portion 28c are positioned so as to be located inside both axial ends of the ring member 28d. Here, since the ring member 28d covers the support portion 28a, both axial ends of the ring member 28d also mean both axial ends of the support portion 28a. As shown in FIG. 11, when the lip seal 28 is assembled into the circumferential groove 30, the tip of the first lip portion 28b abuts against the step surface 8, and the second lip portion 28c abuts against the protrusion 10c.

[About the action and effect of the valve device]
According to the valve device of this embodiment described above, the tip of the first lip portion 28b and the tip of the second lip portion 28c of the lip seal 28 are located inside the axial ends of the support portion 28a, so that the lip portions 28b, 28c are less likely to come into contact with other members. This makes it possible to prevent the lip portions 28b, 28c of the lip seal 28 from being scratched or soiled before use.

Here, the tip of each lip portion 28b, 28c is located inside both axial ends of the ring member 28d, so damage to each lip portion 28b, 28c can be suppressed even when the lip seal 28 is a single component.

According to the configuration of this embodiment, the outer circumference and both ends of the support portion 28a of the lip seal 28 are covered by the ring material 28d, so that the support portion 28a is protected from contact with other members. This makes it possible to prevent the support portion 28a of the lip seal 28 from being damaged before use.

[Modification of the fourth embodiment]
As a modification of this embodiment, as shown in Fig. 13, the metal ring 28d may be omitted from the lip seal 28. Fig. 13 shows a state in which the lip seal 28 is assembled to the large diameter portion 5a of the housing 6 in a cross-sectional view equivalent to Fig. 2. In this assembled state, the first lip portion 28b and the second lip portion 28c come into contact with the step surface 8 and the protruding portion 10c of the EGR pipe 10, respectively, so that the lip portions 28b, 28c are deformed from the state shown by the two-dot chain line to the state shown by the solid line. At this time, a pressing force acts on the lip portions 28b, 28c as shown by the arrows, and the support portion 28a is pressed against the inner peripheral surface of the inlet passage 4b by the force. This improves the adhesion of the lip seal 28 to the outer housing 4, and improves the sealing property of the lip seal 28.

Fifth Embodiment
Next, the fifth embodiment will be described in detail with reference to FIG.

[About housing]
This embodiment differs from the first embodiment in the configuration of the housing 6. Figure 14 shows the valve device 1 of this embodiment in a front view similar to Figure 1. As shown in Figure 14, in the valve device 1 of this embodiment, the housing 6 is not a two-piece component consisting of the inner housing 11 and the outer housing 4, but is composed of a single integrated component. In this respect, the configuration differs from each of the above embodiments. Here, the configuration other than the housing 6 is basically the same as that of the first embodiment. The housing 6 has a valve flange 6a that is fastened to the pipe flange 10a by bolts 21.

[About the action and effect of the valve device]
The configuration of the valve device 1 of this embodiment described above can provide essentially the same functions and effects as those of the first embodiment. However, in this embodiment, since the housing 6 is configured as a single integrated part, the number of parts can be reduced compared to the valve device 1 of the first embodiment.

<Another embodiment>
The disclosed technology is not limited to the above-described embodiments, and may be implemented by modifying part of the configuration as appropriate without departing from the spirit of the disclosed technology.

(1) In each of the above embodiments, the lip portions 18b, 28b, and 28c of the lip seals 18 and 28 are provided facing inward of the lip seals 18 and 28, but the lip portions can also be provided facing outward of the lip seals.

(2) In each of the above embodiments, the valve device 1 is embodied to adjust the flow rate of EGR gas in an EGR device provided in an engine system, but the valve device can also be embodied in a device other than an EGR device, such as an intake device that adjusts the flow rate of intake air or a blow-by gas device that adjusts the flow rate of blow-by gas.

(3) In the first to third and fifth embodiments, the "rubber seal" is a lip seal 18, but the "rubber seal" can also be an O-ring.

This disclosed technology can be applied, for example, to EGR devices and intake devices in engine systems.

Reference Signs List 1 Valve device 4 Outer housing 4a Mounting hole 4d Valve flange 4e Housing end surface 5 Flow passage 5a Large diameter portion 5b Small diameter portion 6 Housing 6a Valve flange 7 Opening 8 Step surface 10 EGR pipe (another pipe member)
10a: Pipe flange 10b: End face 10c: Convex portion 11: Inner housing 13: Valve seat 14: Valve body 15: Valve shaft 16: Actuator 18: Lip seal (rubber seal)
18a Support portion (first end portion)
18b Lip portion (second end portion)
18c Convex strip 26a Convex portion 28 Lip seal (rubber seal)
28a Support portion 28b First lip portion (first end portion)
28c Second lip portion (second end portion)
28d Ring material

Claims (6)

a housing including a fluid flow path;
A valve seat provided in the flow path;
a valve body provided so as to be able to be seated on the valve seat;
a valve shaft having the valve body provided at one end thereof;
and an actuator for axially reciprocating the valve shaft,
The housing has a housing end surface to which another pipe member is fastened via a flange,
an opening of the flow passage is disposed on the end surface of the housing, and an annular stepped surface is provided in the flow passage immediately before the opening, which makes the inner diameter of the flow passage smaller than the inner diameter of the opening, and the flow passage is divided by the stepped surface into a large diameter portion close to the opening and a small diameter portion far from the opening,
a rubber seal is provided in the large diameter portion between the step surface and the pipe member and in contact with the step surface and the pipe member when the pipe member is fastened to the housing end face via the flange. 2. The valve device according to claim 1,
the housing is composed of an inner housing fixed to the actuator and an outer housing including an assembly hole into which the inner housing is assembled, the flow path being formed in a state in which the inner housing is assembled to the assembly hole of the outer housing,
A valve device characterized in that the opening of the housing is provided in the outer housing, the step surface is formed by an end face of the inner housing, and the large diameter portion is formed by the inner surface of the outer housing and the step surface. The valve device according to claim 2,
The valve device according to claim 1, wherein the rubber seal includes a protrusion on an outer periphery thereof facing radially outward. The valve device according to any one of claims 1 to 3,
the rubber seal includes a first end portion in an axial direction thereof that abuts against the step surface and a second end portion that abuts against the pipe member,
When the pipe member is removed from the housing end face and the rubber seal is disposed on the large diameter portion, the second end of the rubber seal is configured to be located inside the large diameter portion with respect to the housing end face,
the pipe member is provided with a protrusion that fits into the large diameter portion and abuts against the second end of the rubber seal when the pipe member is fastened to the housing end face. The valve device according to any one of claims 1 to 3,
The rubber seal is formed by a lip seal including an annular support portion, and a first lip portion and a second lip portion that protrude inward from the support portion and are inclined in directions away from each other,
A valve device characterized in that, when the lip seal is in a released state, a tip of the first lip portion and a tip of the second lip portion are positioned inwardly of both axial ends of the support portion. 6. The valve device according to claim 5,
A valve device characterized in that the outer periphery and both ends of the support portion are covered with a metal ring material.

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