Valve device

Abstract

To even out the surface pressure of a rubber seal in the case of fastening a housing end face with a different pipe member, and to improve sealing performance of the rubber seal between a housing and the different pipe member.SOLUTION: A valve device 1 comprises: a housing 6 including a flow passage 5; a valve seat 13 arranged in the flow passage 5; a valve body 14 that can seat on the valve seat 13; a valve shaft 15 provided with the valve body 14; and an actuator 16 for reciprocating the valve shaft 15. The housing 6A has a housing end face 4e to which an EGR pipe 10 is fastened via flanges 10a, 4d . The housing end face 4e has an annular step face 8 which makes an inner diameter of the flow passage 5 smaller than an inner diameter of an opening 7 immediately in front of the opening 7 of the flow passage 5, the flow passage 5 being divided into a large-diameter part 5a closer to the opening 7 and a small-diameter part 5b farther from the opening 7 across the step face 8. With the EGR pipe 10 being fastened to the housing end face 4e, a lip seal 18 contacting the step face 8 and the EGR pipe 10 is arranged in the large-diameter part 5a between the step face 8 and the EGR pipe 10.SELECTED DRAWING: Figure 1

Description

Technical Field

[0001] The technology disclosed in this specification relates to a valve device for regulating the flow rate of a fluid.

Background Art

[0002] Conventionally, as this type of technology, for example, the technology “exhaust gas recirculation control valve device” described in the following Patent Document 1 is known. This device includes 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 provided at one end of the valve body, and a drive unit for reciprocating the valve shaft. An EGR pipe (another pipe member) is fastened to the end face of the housing corresponding to the inlet (opening) of the flow path by a plurality of bolts via a flange. An annular packing is sandwiched and provided between the end face of the housing and one end of the pipe member to ensure airtightness.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, in the device described in Patent Document 1, since a packing is provided between the end face of the housing fastened by bolts and one end of the pipe member, particularly in the vicinity of the bolts, a strong surface pressure is applied to the packing, and warping of the flange is likely to occur. Here, since the closer the distance between the bolt and the packing, the greater the surface pressure applied to the packing, the surface pressure becomes non-uniform in the circumferential direction of the packing, and there is a possibility that the sealing performance of the packing becomes non-uniform.

[0005] This disclosed technology has been made in view 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 pipe member, thereby improving the sealing performance of the rubber seal between the housing and the other pipe member. [Means for solving the problem]

[0006] To achieve the above objective, the technology described in claim 1 includes a housing including a fluid passage, a valve seat provided in the passage, a valve body provided so as to be seatable on the valve seat, a valve stem provided at one end of the valve body, and an actuator for reciprocating the valve stem in the axial direction. 、 In a valve device equipped with a housing, another pipe member is connected to the housing via a flange. By bolt A housing end face is provided to be fastened, and a flow channel opening is located on the housing end face. Immediately before the opening, an annular stepped surface is provided in the flow channel that reduces the inner diameter of the flow channel to less than the inner diameter of the opening, dividing the flow channel into a large-diameter section near the opening and a small-diameter section far from the opening, with the pipe member fastened to the housing end face via a flange, and a rubber seal is provided in the large-diameter section between the stepped surface and the pipe member, contacting both the stepped surface and the pipe member. Furthermore, radially inward from the bolt, the housing end face and the pipe member end face are in contact without the intervening seal member. This is the purpose.

[0007] According to the above technology configuration, another pipe member is fastened to the housing end face via a flange. The flow path immediately before the opening at the housing end face is divided by a stepped surface into a large-diameter section near the opening and a small-diameter section far from the opening. With the pipe member fastened to the housing end face via a flange, a rubber seal is provided in the large-diameter section between the stepped surface and the pipe member, making contact with both the stepped surface and the pipe member. Therefore, since the rubber seal is positioned in the large-diameter section of the flow path and makes contact with the stepped surface and the pipe member, the space between the housing and the pipe member is sealed by the rubber seal. Furthermore, the rubber seal is not compressed between the housing end face and the pipe member, and its entire circumference makes even contact with the stepped surface and the pipe member.

[0008] To achieve the above objective, the technology described in claim 2 is characterized in that, in the technology described in claim 1, the housing comprises an inner housing fixed to an actuator and an outer housing including an assembly hole into which the inner housing is assembled, a flow path is formed when the inner housing is assembled into the assembly hole of the outer housing, the opening of the housing is provided in the outer housing, the stepped surface is formed by the end face of the inner housing, and the large diameter portion is formed by the inner surface of the outer housing and the stepped surface.

[0009] According to the configuration of the above technology, in addition to the operation 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 is assembled as needed.

[0010] To achieve the above objective, the technology described in claim 3 is intended to be the technology described in claim 2, wherein the rubber seal includes radially outward-facing protrusions on its outer circumference.

[0011] According to the configuration of the above technology, in addition to the operation of the technology described in claim 2, when the inner housing is assembled into the assembly hole of the outer housing, the protrusions of the rubber seal provided on the large diameter portion come into contact with the inner surface of the outer housing, thereby sealing the space between the outer housing and the inner housing. Therefore, it becomes possible to omit another sealing member that seals the space between the outer housing and the inner housing near the opening.

[0012] To achieve the above objective, the technology described in claim 4 is: A valve device comprising a housing containing a fluid passage, a valve seat provided in the passage, a valve body seatable on the valve seat, a valve stem with the valve body at one end, and an actuator for reciprocating the valve stem in the axial direction, wherein the housing is provided with a housing end face to which another pipe member is fastened via a flange, an opening for the passage is located at the housing end face, an annular stepped surface is provided in the passage immediately before the opening, reducing the inner diameter of the passage to less than the inner diameter of the opening, the passage is divided at the stepped surface into a large-diameter section near the opening and a small-diameter section 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 section between the stepped surface and the pipe member, contacting both the stepped surface and the pipe member. The rubber seal includes a first end that abuts against a stepped surface in its axial direction and a second end that abuts against the pipe member. The configuration is such that when the pipe member is removed from the housing end face and the rubber seal is positioned in the large-diameter portion, the second end of the rubber seal is positioned inside the large-diameter portion from 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.

[0013] According to the above technology configuration, 1 In addition to the effects of the described technology, when the rubber seal is positioned in the large-diameter section, the second end of the rubber seal is located inside the large-diameter section from the housing end face. Therefore, before fastening the pipe member to the housing end face, the rubber seal positioned in the large-diameter section is less likely to come into contact with other members.

[0014] To achieve the above objective, the technology described in claim 5 is: A valve device comprising a housing containing a fluid passage, a valve seat provided in the passage, a valve body seatable on the valve seat, a valve stem with the valve body at one end, and an actuator for reciprocating the valve stem in the axial direction, wherein the housing is provided with a housing end face to which another pipe member is fastened via a flange, an opening for the passage is located at the housing end face, an annular stepped surface is provided in the passage immediately before the opening, reducing the inner diameter of the passage to less than the inner diameter of the opening, the passage is divided at the stepped surface into a large-diameter section near the opening and a small-diameter section 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 section between the stepped surface and the pipe member, contacting both the stepped surface and the pipe member. 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 toward each other. The purpose is that, when the lip seal is released, the tips of the first lip portion and the tips of the second lip portion are positioned inward from both ends of the support portion in the axial direction.

[0015] According to the above technology configuration, 1 In addition to the effects of the described technology, since the tips of the first and second lip portions of the lip seal are located inward from both axial ends of the support portion, each lip portion is less likely to come into contact with other components.

[0016] To achieve the above objective, the technology described in claim 6 is intended to be the technology described in claim 5, wherein the outer circumference and both ends of the support portion are covered with a metal ring material.

[0017] According to the configuration of the above technology, in addition to the effects of the technology described in claim 5, the outer circumference and both ends of the support portion are covered with a ring material, so that the support portion is protected from contact with other members. [Effects of the Invention]

[0018] According to the technology described in claim 1, even when the housing end face is fastened to another pipe 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 pipe member can be improved.

[0019] According to the technique described in claim 2, in addition to the effects of the technique described in claim 1, for example, after configuring the assembly hole of the inner housing and the outer housing in a common form, the form of the outer housing can be variously changed as required.

[0020] According to the technique described in claim 3, in addition to the effects of the technique described in claim 2, the number of components of the valve device can be reduced by the amount that another sealing member can be omitted, which is advantageous for reducing man-hours and costs. Further, since no other sealing member is provided between the outer housing and the inner housing, the press-fitting resistance when the inner housing is assembled (inserted) into the assembly hole 4a can be reduced, and it becomes easier to assemble (insert) the inner housing into the assembly hole.

[0021] 請求項4に記載の技術によれば、請求項 1 According to the technique described in claim 4, in addition to the effects of the technique described in claim

[0022] 請求項5に記載の技術によれば、請求項 1 it is possible to prevent damage and contamination of the rubber seal assembled to the housing before another pipe member is fastened to the housing.

[0023] According to the technique described in claim 6, in addition to the effects of the technique described in claim 5, it is possible to prevent damage to the support portion of the lip seal before use.

Brief Description of the Drawings

[0024] [Figure 1] Front view showing a partially cut-away valve device according to the first embodiment. [Figure 2] Enlarged cross-sectional view showing the portion surrounded by the two-dot chain line rectangle of the valve device in FIG. 1 according to the first embodiment. [Figure 3] Front view corresponding to FIG. 1 showing a valve device according to the second embodiment. [Figure 4] Enlarged cross-sectional view corresponding to FIG. 2 showing a part of the valve device according to the second embodiment. [Figure 5] A front view relating to the second embodiment, similar to Figure 3, showing the EGR pipe removed from the housing end face. [Figure 6] An enlarged cross-sectional view relating to the second embodiment, showing the EGR pipe removed from the housing end face, similar to Figure 4. [Figure 7] This is an enlarged cross-sectional view, similar to Figure 4, relating to the second embodiment, showing the state in which the EGR pipe is fastened to the housing end face from the state shown in Figure 6. [Figure 8] A front view relating to the third embodiment, showing a valve device, similar to Figure 1. [Figure 9] This is a front view relating to the third embodiment, similar to Figure 5, showing the state in which the EGR pipe has been removed from the housing end face from the state in Figure 8. [Figure 10] A cross-sectional view showing a flange material used in a pipe flange, relating to a modified example of the third embodiment. [Figure 11] A front view relating to the fourth embodiment, showing a valve device, similar to Figure 8. [Figure 12] A cross-sectional view showing the lip seal cut radially, relating to the fourth embodiment. [Figure 13] A cross-sectional view relating to Figure 2, showing a modified version of the fourth embodiment, in which the lip seal is assembled to the large-diameter portion of the housing. [Figure 14] A front view relating to the fifth embodiment, showing a valve device, similar to Figure 1. [Modes for carrying out the invention]

[0025] Below, several embodiments of the valve device implemented in the EGR system will be described in detail with reference to the drawings.

[0026] <First Embodiment> First, the first embodiment will be described in detail with reference to Figures 1 and 2.

[0027] [Regarding the configuration of the valve device] Figure 1 shows a partially cutaway front view of the valve device 1 of this embodiment. This valve device 1 is installed in an EGR passage (not shown) connected to the intake passage in order to return a portion of the exhaust gas discharged from the engine to the exhaust passage as EGR gas back to the engine. The valve device 1 comprises an EGR valve 2 and an EGR pipe 10 connected thereto. The EGR valve 2 is used to regulate the flow rate of EGR gas in the EGR passage. The EGR pipe 10 corresponds to an example of "another tubular member" in this disclosed technology.

[0028] As shown in Figure 1, the EGR valve 2 has a poppet-type valve structure and consists of a valve assembly 3 and an outer housing 4 into which the inner housing 11 is assembled. The outer housing 4 is made of resin. The inner housing 11 and the outer housing 4 constitute the housing 6 of the EGR valve 2. The valve assembly 3 includes a substantially cylindrical inner housing 11 containing an EGR gas flow path 12, an annular valve seat 13 provided in the flow path 12, a substantially umbrella-shaped valve body 14 seatable on the valve seat 13 for opening and closing the flow path 12, a valve stem 15 with the valve body 14 at one end, and an actuator 16 for reciprocating the valve stem 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 resin. The actuator 16 can be made of, for example, a DC motor.

[0029] As shown in Figure 1, the flow path portion 12 of the inner housing 11 is formed by bending in a substantially L-shape and includes an inlet 12a and an outlet 12b. In this embodiment, the inlet 12a opens at the axial lower end of the inner housing 11, and the outlet 12b opens on the outer circumference of the inner housing 11. In this embodiment, the valve seat 13 and valve body 14 are made of metal. The shapes of the valve seat 13 and 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 path portion 12 by moving the valve body 14 relative to the valve seat 13 and changing the opening between the valve seat 13 and the valve body 14. In this embodiment, a detailed description of the actuator 16 is omitted.

[0030] The valve stem 15 extends downward from the actuator 16 and passes through the inner housing 11. A rubber sealing member 17 is provided between the inner housing 11 and the valve stem 15. The valve stem 15 is positioned parallel to the axis of the valve seat 13. The valve body 14 is designed to seat (contact) and separate from the valve seat 13 as the valve stem 15 is reciprocated. A lip seal 18 is also provided between the outer housing 4, the inner housing 11, and the EGR pipe 10 to seal the space between them. In this embodiment, the valve body 14 is movably positioned below (upstream of) the valve seat 13. The lip seal 18 is an example of a "rubber seal" in this disclosed technology.

[0031] As shown in Figure 1, in this embodiment, the outer housing 4 has a substantially cylindrical shape and includes an assembly hole 4a for assembling the inner housing 11, an inlet passage 4b, and an outlet 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, with the inner housing 11 assembled into the assembly hole 4a, the inlet passage 4b ​​communicates with the inlet 12a of the inner housing 11, and the outlet passage 4c communicates with the outlet 12b of the inner housing 11. That is, in this embodiment, with the inner housing 11 assembled into the assembly hole 4a of the outer housing 4, the passage section 12, the inlet passage 4b, and the outlet passage 4c constitute the passage 5 of this disclosed technology.

[0032] As shown in Figure 1, in this embodiment, a total of three rubber sealing members 18, 19, and 20 are provided between the inner housing 11 and the outer housing 4 near the inlet 12a and outlet 12b of the inner housing 11. Specifically, in Figure 1, the first O-ring 19 is provided on the outer circumference of the inner housing 11 above the outlet 12b, and the second O-ring 20 is provided on the outer circumference of the inner housing 11 near the inlet 12a. Furthermore, in Figure 1, the aforementioned lip seal 18 is provided at the lower end of the inner housing 11, between the area around the inlet 12a and the inner surface of the outer housing 4.

[0033] In Figure 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 EGR valve 2 and the EGR pipe 10 are fastened together by bolts 21 at these flanges 4d and 10a. A housing end face 4e is provided at the lower end of the outer housing 4, which is fastened by bolts 21 via the pipe flange 10a.

[0034] [About lip seals] Figure 2 shows an enlarged cross-sectional view of the portion of the valve device 1 in Figure 1 enclosed by the dashed rectangle S1. As shown in Figures 1 and 2, in this embodiment, an opening 7 of the flow path 5 is located on the housing end face 4e. An annular stepped surface 8 is provided in the inlet flow path 4b immediately before the opening 7, reducing the inner diameter of the inlet flow path 4b to that of the opening 7. The flow path 5 is then divided at the stepped surface 8 into a large-diameter portion 5a close to the opening 7 and a small-diameter portion 5b far from the opening 7. The inner housing 11 is assembled into the assembly hole 4a of the outer housing 4, and the EGR pipe 10 is fastened to the housing end face 4e via the pipe flange 10a using bolts 21. In the large-diameter portion 5a, a lip seal 18 is provided between the stepped surface 8 and the end face 10b of the EGR pipe 10, contacting both the stepped surface 8 and the end face 10b. In this embodiment, the opening 7 of the housing 6 is provided in the outer housing 4, the stepped surface 8 is formed by the end face of the inner housing 11, and the large diameter portion 5a is formed from the inner circumferential surface of the outer housing 4 and the stepped surface 8.

[0035] As shown in Figure 2, the lip seal 18 of this embodiment has a substantially V-shaped radial cross-section, and includes a support portion 18a that contacts the stepped surface 8 and supports the lip seal 18 in the housing 6 (inner housing 11), and a lip portion 18b that contacts the end face 10b of the EGR pipe 10 and seals the space 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.

[0036] [Regarding the operation and effects of valve devices] 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 at the housing end face 4e is divided by the stepped surface 8 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 face 4e via the pipe flange 10a and the valve flange 4d by bolts 21, a lip seal 18 is provided in the large-diameter portion 5a between the stepped surface 8 and the EGR 10, in contact with the stepped surface 8 and the end face 10b of the EGR pipe 10. Therefore, since the lip seal 18 is positioned in the large-diameter portion 5a of the flow path 5 and in contact with the stepped surface 8 and the end face 10b, the space 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 in even contact with the stepped 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 pipe member) are fastened together with bolts 21, the surface pressure around the entire circumference of the lip seal 18 can be made uniform, and the sealing performance by the lip seal 18 between the housing 6 (outer housing 4) and the EGR pipe 10 can be improved.

[0037] In this embodiment, no sealing 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 positioned between the stepped surface 8 in the flow path 5 and the end face 10b of the EGR pipe 10. Therefore, although the valve flange 4d may bend when the bolts 21 are fastened, the housing end face 4e will not bend even if the valve flange 4d bends. 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. Therefore, the valve flange 4d can be made thinner, which is advantageous for weight reduction and cost reduction.

[0038] 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 is assembled as needed. For this reason, for example, the inner housing 11 and the assembly hole 4a can be configured in a common form, and the form of the outer housing 4 can be changed in various ways as needed.

[0039] According to the configuration of this embodiment, since the lip seal 18 is housed in the large-diameter portion 5a of the flow path 5 of the housing 6, there is no need to insert 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.

[0040] <Second Embodiment> Next, the second embodiment will be described in detail with reference to Figures 3 to 7. In the following description, components equivalent to those in the first embodiment will be denoted by the same reference numerals and their descriptions will be omitted. The following description will focus on the differences.

[0041] [Regarding sealing materials] This embodiment differs from the first embodiment in terms of the configuration of the lip seal 18. Figure 3 shows the valve device 1 of this embodiment in a front view corresponding to Figure 1. Figure 4 shows a part of the valve device 1 of this embodiment in an enlarged cross-sectional view corresponding to Figure 2. As shown in Figures 3 and 4, the lip seal 18 of this embodiment has the same configuration as the first embodiment, in addition to including a radially outward-facing protrusion 18c on its outer circumference. This protrusion 18c is formed continuously along the outer circumference of the lip seal 18 and elastically contacts the inner circumferential surface of the outer housing 4, having the function of sealing the space between the outer housing 4 and the inner housing 11. For this reason, the second O-ring 20 is omitted in this embodiment.

[0042] Figure 5 shows a front view, similar to Figure 3, of this embodiment, in which the EGR pipe 10 has been removed from the housing end face 4e. Figure 6 shows an enlarged cross-sectional view, similar to Figure 4, of this embodiment, in which the EGR pipe 10 has been removed from the housing end face 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 assembled 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.

[0043] Figure 7 shows an enlarged cross-sectional view, similar to that in Figure 4, of this embodiment, showing the state in which the EGR pipe 10 is fastened to the housing end face 4e from the state shown in Figure 6. During 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 deforms from the state shown by the dashed 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 protrusion 18c against the inner circumferential surface of the outer housing 4. For this reason, although the second O-ring 20 is omitted in this embodiment, the function of the second O-ring 20 can be ensured, and moreover, its sealing function can be improved.

[0044] [Regarding the operation and effects of valve devices] As described above, with the valve device 1 of this embodiment configured, when the inner housing 11 is assembled into the assembly hole 4a of the outer housing 4, the protrusion 18c of the lip seal 18 provided on the large diameter portion 5a contacts the inner surface of the outer housing 4, thereby sealing the space between the outer housing 4 and the inner housing 11. Therefore, it becomes possible to omit another sealing member (for example, the second O-ring 20 in the first embodiment) that seals the space between the outer housing 4 and the inner housing 11 near the opening 7. As a result, the number of parts in the valve device 1 can be reduced by the amount by which another sealing member can be omitted, which is advantageous in reducing man-hours and costs. In addition, since no other sealing member is provided between the outer housing 4 and the inner housing 11, the press-fitting resistance when assembling (inserting) 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.

[0045] In this embodiment, even when exhaust pressure acts on the flow path 5 with the lip seal 18 assembled in the EGR valve 2, the lip portion 18b acts in the closing direction. Therefore, the sealing function can be improved even against gas leakage to the atmosphere due to exhaust pressure.

[0046] <Third Embodiment> Next, the fourth embodiment will be described in detail with reference to Figures 8 and 9.

[0047] [About lip seals] In this embodiment, the configuration differs from the second embodiment in terms of the arrangement of the lip seal 18, etc. Figure 8 shows the valve device 1 of this embodiment in a front view corresponding to Figure 1. Figure 9 shows the state in this embodiment in which the EGR pipe 10 has been removed from the housing end face 4e from the state in Figure 8, in a front view corresponding to Figure 5. In the second embodiment, as shown in Figures 5 and 6, when the EGR pipe 10 is pulled away from the housing end face 4e, the tip of the lip portion 18b of the lip seal 18 protrudes out of the opening 7 of the housing 6 (outer housing 4). Therefore, 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 contaminated with dirt. In this embodiment, the following countermeasures were taken.

[0048] In other words, in this embodiment, as shown in Figure 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 on the large-diameter portion 5a, the lip portion 18b is positioned inside the large-diameter portion 5a from the housing end face 4e. Furthermore, 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.

[0049] [Regarding the operation and effects of valve devices] According to the configuration of the valve device 1 of this embodiment described above, with the lip seal 18 positioned on the large-diameter portion 5a, the lip portion 18b (second end) of the lip seal 18 is located inside the large-diameter portion 5a from the housing end face 4e. Therefore, the lip seal 18 positioned on the large-diameter portion 5a is less likely to come into contact with other members before the EGR pipe 10 (another pipe member) is fastened to the housing end face 4e. As a result, damage or contamination of the lip seal 18 assembled to the housing 6 can be prevented before the EGR pipe 10 is fastened to the housing 6.

[0050] [Modified version of the third embodiment] As a modification of this embodiment, as shown in Figure 10, a flange material 26 having a protrusion 26a formed by press-forming a metal plate 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. Figure 10 shows a cross-sectional view of the flange material 26 used for this modification in the pipe flange 10a.

[0051] <Fourth Embodiment> Next, the fourth embodiment will be described in detail with reference to Figures 11 and 12.

[0052] [About lip seals] This embodiment differs from the second and third embodiments in terms of the configuration of the lip seal 28. Figure 11 shows the valve device 1 of this embodiment in a front view corresponding to Figure 8. Figure 12 shows the lip seal 28 of this embodiment in a radially cut cross-sectional view. As shown in Figure 11, in this embodiment, a circumferential groove 30 continuous in the inner circumferential direction is formed on the inner wall of the large diameter portion 5a of the inlet passage 4b ​​of the outer housing 4, and the lip seal 28 is assembled into this circumferential groove 30.

[0053] As shown in Figures 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 toward each other. These portions 28a to 28c are integrally formed from rubber material. The outer circumference and both ends of the support portion 28a are covered by a metal ring member 28d. When the lip seal 28 is released, that is, when the lip seal 28 is released without contacting other members, the tips of the first lip portion 28b and the tips of the second lip portion 28c are positioned inward from the axial ends of the ring member 28d. Here, since the ring member 28d covers the support portion 28a, the axial ends of the ring member 28d also refer to the axial ends of the support portion 28a. As shown in Figure 11, when the lip seal 28 is assembled in the circumferential groove 30, the tip of the first lip portion 28b abuts against the stepped surface 8, and the second lip portion 28c abuts against the convex portion 10c.

[0054] [Regarding the operation and effects of valve devices] As described above, with the valve device configuration of this embodiment, the tips of the first lip portion 28b and the second lip portion 28c of the lip seal 28 are located inward from both axial ends of the support portion 28a, so that the lip portions 28b and 28c are less likely to come into contact with other members. Therefore, it is possible to prevent damage or contamination of the lip portions 28b and 28c of the lip seal 28 before use.

[0055] Here, since the tips of each lip portion 28b, 28c are located inward from both axial ends of the ring material 28d, damage to each lip portion 28b, 28c can be suppressed even when the lip seal 28 is considered as a standalone component.

[0056] 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. Therefore, it is possible to prevent damage to the support portion 28a of the lip seal 28 before use.

[0057] [Modified version of the fourth embodiment] As a variation of this embodiment, the metal ring member 28d can be omitted from the lip seal 28, as shown in Figure 13. Figure 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 similar to that of Figure 2. In this assembled state, the first lip portion 28b and the second lip portion 28c come into contact with the stepped surface 8 and the protrusion 10c of the EGR pipe 10, respectively, causing each lip portion 28b, 28c to deform from the state shown by the dashed line to the state shown by the solid line. At this time, a pressing force acts on each lip portion 28b, 28c as shown by the arrows, and this force presses the support portion 28a against the inner circumferential surface of the inlet passage 4b. As a result, the adhesion of the lip seal 28 to the outer housing 4 can be improved, and the sealing performance of the lip seal 28 can be improved.

[0058] <Fifth Embodiment> Next, a fifth embodiment will be described in detail with reference to Figure 14.

[0059] [About Housing] This embodiment differs from the first embodiment in terms of the configuration of the housing 6. Figure 14 shows the valve device 1 of this embodiment in a front view corresponding to Figure 1. As shown in Figure 14, the valve device 1 of this embodiment has a housing 6 that is not composed of two parts, an inner housing 11 and an outer housing 4, but is composed of a single integrated part. In this respect, the configuration differs from the embodiments described above. 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 with a pipe flange 10a and bolts 21.

[0060] [Regarding the operation and effects of valve devices] With the configuration of the valve device 1 of this embodiment described above, it is possible to obtain basically the same operation and effects as the first embodiment. However, in this embodiment, since the housing 6 is made up of a single integrated part, the number of parts can be reduced compared to the valve device 1 of the first embodiment.

[0061] <Another embodiment> Furthermore, this disclosed technology is not limited to the embodiments described above, and it may be implemented by appropriately modifying some parts of the configuration without departing from the spirit of the disclosed technology.

[0062] (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, but the lip portions may also be provided facing outward.

[0063] (2) In each of the above embodiments, the valve device 1 is embodied in an EGR device provided in an engine system for adjusting the flow rate of EGR gas. However, it can also be embodied in a valve device for a device other than an EGR device, such as an intake device for adjusting the flow rate of intake air or a blow-by gas device for adjusting the flow rate of blow-by gas.

[0064] (3) In the first to third and fifth embodiments described above, the "rubber seal" is a lip seal 18, but the "rubber seal" can also be an O-ring. [Industrial applicability]

[0065] This disclosed technology can be applied, for example, to EGR devices and intake systems in engine systems. [Explanation of Symbols]

[0066] 1 Valve device 4. Exterior Housing 4a Assembly hole 4d valve flange 4e Housing end face 5 channels 5a Large diameter section 5b Kokarube 6 Housing 6a Valve flange 7 aperture 8 steps 10 EGR pipe (another pipe component) 10a Pipe flange 10b End face 10c convex part 11 Inner Housing 13 valve seats 14 Valve body 15 Valve stem 16 Actuators 18 Lip seals (rubber seals) 18a Support part (first end) 18b Lip section (second end) 18c Convex stripe 26a Convex part 28 Lip seals (rubber seals) 28a Support part 28b First lip section (first end) 28c Second lip section (second end) 28d ring material

Claims

1. A housing including a fluid passage, A valve seat provided in the aforementioned flow path, A valve body provided so as to be seatable on the valve seat, The valve body is provided at one end of the valve stem, An actuator for reciprocating the valve shaft in the axial direction, In a valve device equipped with, The housing is provided with a housing end face to which another pipe member is fastened by bolts via a flange, An opening for the flow path is provided on the end face of the housing, and an annular stepped surface is provided in the flow path immediately before the opening, reducing the inner diameter of the flow path to a smaller diameter than the inner diameter of the opening, with the step dividing the flow path into a large-diameter portion close to the opening and a small-diameter portion far from the opening. With the pipe member fastened to the housing end face via the flange, the large diameter portion is provided with a rubber seal that contacts the stepped surface and the pipe member between the stepped surface and the pipe member. Further inward from the bolt, the housing end face and the pipe member end face are in contact without the presence of a sealing member. A valve device characterized by the following features.

2. In the valve device according to claim 1, The housing consists of an inner housing fixed to the actuator and an outer housing including an assembly hole into which the inner housing is assembled, and the flow path is configured when the inner housing is assembled into the assembly hole of the outer housing. The opening of the housing is provided in the outer housing, the stepped surface is formed by the end face of the inner housing, and the large diameter portion is formed from the inner surface of the outer housing and the stepped surface. A valve device characterized by the following features.

3. In the valve device according to claim 2, The rubber seal includes a convex ridge on its outer circumference that is oriented radially outward. A valve device characterized by the following features.

4. A housing including a fluid passage, A valve seat provided in the aforementioned flow path, A valve body provided so as to be seatable on the valve seat, The valve body is provided at one end of the valve shaft, An actuator for reciprocating the valve shaft in the axial direction, In a valve device equipped with, The housing is provided with a housing end face to which another pipe member is fastened via a flange, An opening for the flow path is provided on the end face of the housing, and an annular stepped surface is provided in the flow path immediately before the opening, reducing the inner diameter of the flow path to a smaller diameter than the inner diameter of the opening, with the step dividing the flow path into a large-diameter portion close to the opening and a small-diameter portion far from the opening. With the pipe member fastened to the housing end face via the flange, the large diameter portion is provided with a rubber seal that contacts the stepped surface and the pipe member between the stepped surface and the pipe member. The rubber seal includes a first end that abuts the stepped surface in its axial direction and a second end that abuts the pipe member. With the pipe member removed from the housing end face and the rubber seal positioned in the large-diameter portion, the second end of the rubber seal is configured to be located inside the large-diameter portion from the housing end face. The pipe member is provided with a protrusion that, when the pipe member is fastened to the housing end face, fits into the large-diameter portion and abuts against the second end of the rubber seal. A valve device characterized by the following features.

5. A housing including a fluid channel, A valve seat provided in the aforementioned flow path, A valve body provided so as to be seatable on the valve seat, The valve body is provided at one end of the valve shaft, An actuator for reciprocating the valve shaft in the axial direction, In a valve device equipped with, The housing is provided with a housing end face to which another pipe member is fastened via a flange, An opening for the flow path is provided on the end face of the housing, and an annular stepped surface is provided in the flow path immediately before the opening, reducing the inner diameter of the flow path to a smaller diameter than the inner diameter of the opening, with the step dividing the flow path into a large-diameter portion close to the opening and a small-diameter portion far from the opening. With the pipe member fastened to the housing end face via the flange, the large diameter portion is provided with a rubber seal that contacts the stepped surface and the pipe member between the stepped surface and the pipe member. 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 a direction away from each other. In the open state of the lip seal, the tip of the first lip portion and the tip of the second lip portion are positioned inward from both axial ends of the support portion. A valve device characterized by the following features.

6. In the valve device according to claim 5, The outer circumference and both ends of the support portion are covered with a metal ring. A valve device characterized by the following features.

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