This application claims the priority benefit of Japan Application No. 2018-158898, filed on Aug. 28, 2018. The entirety of the above-mentioned patent application is hereby incorporated by reference herein and made a part of this specification.
The disclosure relates to a pressure control device.
As an oil pressure control device for controlling oil pressure, for example, an oil pressure control device mounted on a motorcar and used in a clutch is known (for example, see patent literature 1). The oil pressure control device described in patent literature 1 includes a body having a flow path through which hydraulic oil passes, and a cylindrical filter which is arranged in the middle of the flow path and captures foreign matter such as powder mixed in the hydraulic oil.
In addition, generally in the oil pressure control device, when the filter is inserted into the flow path of the body and the members are assembled to manufacture an oil pressure control device, the assembly work is usually performed manually, for example.
However, in the oil pressure control device described in patent literature 1, there is a tendency that the narrower the flow path is, that is, the smaller a width of the flow path is, the more difficult it is to perform the work of inserting the filter into this flow path. Therefore, the filter may be in a state of not being properly inserted into the flow path. In this case, for example, the filter may fall off the body if the body and the filter are turned upside down during assembly or excessive vibration is applied during transportation even after assembly.
[Patent literature 1] Japanese Laid-open No. 2014-234829
An aspect of the pressure control device of the disclosure includes: a body, which has a flow path including a groove and a widening portion that is connected to the groove and has a width larger than the width of the groove to a bottom portion of the groove; and a filter unit, which is accommodated along a depth direction of the widening portion and captures foreign matter mixed in a fluid passing through the flow path. The filter unit has a detachment prevention portion which prevents a detachment from the widening portion.
The embodiments of the disclosure provide a pressure control device capable of reliably preventing a body and a filter unit which are assembled from being disassembled unintentionally.
According to an aspect of the disclosure, the body and the filter unit which are assembled can be prevented from being disassembled unintentionally.
In the following, a pressure control device of the disclosure is described in detail based on suitable embodiments shown in the accompanying diagrams.
A Z-axis direction in each drawing is set as an up-down direction Z. An X-axis direction is set as a left-right direction X within horizontal directions orthogonal to the up-down direction Z. A Y-axis direction is set as an axial direction Y which is orthogonal to the left-right direction X within the horizontal directions orthogonal to the up-down direction Z. A positive side of the up-down direction Z is referred to as an “upper side”, and a negative side of the up-down direction Z is referred to as a “lower side”. A positive side of the axial direction Y is referred to as a “front side”, and a negative side of the axial direction Y is referred to as a “rear side”. The front side corresponds to one side of the axial direction, and the rear side corresponds to the other side of the axial direction. Besides, the upper side, the lower side, the front side, the rear side, the up-down direction, and the left-right direction are simply named for describing relative position relationships of the respective portions, and actual disposition relationships may be other disposition relationships except the disposition relationships shown by these names. In addition, a “plan view” refers to a state when viewing from the upper side to the lower side.
In the following, a first embodiment of the pressure control device of the disclosure is described with reference to
A pressure control device 10 of this embodiment shown in
As shown in
The lower body 21 has a lower body main part 21a and a separate plate 21b which is disposed overlapping with the upper side of the lower body main part 21a. In the embodiment, an upper surface of the lower body 21 corresponds to an upper surface of the separate plate 21b and is orthogonal to the up-down direction Z. The upper body 22 is disposed overlapping with the upper side of the lower body 21. A lower surface of the upper body 22 is orthogonal to the up-down direction Z. The lower surface of the upper body 22 contacts with the upper surface of the lower body 21, that is, the upper surface of the separate plate 21b.
As shown in
The spool hole 23 is open at least on the front side. In the embodiment, a rear end of the spool hole 23 is blocked. That is, the spool hole 23 is a hole which is open on the front side and has a bottom portion. Besides, the spool hole 23 may also be, for example, open on both sides of the axial direction Y. At least a part of the spool hole 23 constitutes a part of the oil passage 10a in the oil passage body 20.
The spool hole 23 has a spool hole main part 23a and an introduction hole portion 23b. Although illustration is omitted, the oil passage 10a which is arranged in the part of the oil passage body 20 other than the spool hole 23 is open on an inner peripheral surface of the spool hole main part 23a. An inner diameter of the introduction hole portion 23b is larger than an inner diameter of the spool hole main part 23a. The introduction hole portion 23b is connected to a front end portion of the spool hole main part 23a. The introduction hole portion 23b is a front end portion of the spool hole 23 and is open on the front side.
As shown in
As shown in
As shown in
As shown in
As shown in
The spool valve 30 moves in the axial direction Y in the spool hole main part 23a, and opens and closes an opening portion of the oil passage 10a which is open on the inner peripheral surface of the spool hole main part 23a. Although illustration is omitted, an oil pressure of oil or a force toward the front side from a driving device such as a solenoid actuator is applied to the rear end portion of the spool valve 30. The spool valve 30 has a support portion 31a, a plurality of large diameter portions 31b, and a plurality of small diameter portions 31c. Each portion of the spool valve 30 has a columnar shape that extends in the axial direction Y about the central axis J.
The support portion 31a is a front end portion of the spool valve 30. A front end portion of the support portion 31a supports a rear end portion of the magnet holder 80. A rear end portion of the support portion 31a is connected to a front end portion of the large diameter portion 31b.
The plurality of large diameter portions 31b and the plurality of small diameter portions 31c are disposed alternately in succession from the large diameter portion 31b connected to the rear end portion of the support portion 31a toward the rear side. An outer diameter of the large diameter portion 31b is larger than an outer diameter of the small diameter portion 31c. In the embodiment, an outer diameter of the support portion 31a is, for example, the same as the outer diameter of the small diameter portion 31c. The outer diameter of the large diameter portion 31b is substantially the same as an inner diameter of the spool hole main part 23a, and is slightly smaller than the inner diameter of the spool hole main part 23a. The large diameter portion 31b can move in the axial direction Y while sliding with respect to the inner peripheral surface of the spool hole main part 23a. The large diameter portion 31b functions as a valve portion which opens and closes the opening portion of the oil passage 10a being open on the inner peripheral surface of the spool hole main part 23a. In the embodiment, the spool valve 30 is, for example, a single member made of metal.
The magnet holder 80 is disposed on the front side of the spool valve 30. The magnet holder 80 is disposed to be movable in the axial direction Y inside the introduction hole portion 23b. The spool valve 30 and the magnet holder 80 are allowed to rotate relatively around the central axis. As shown in
The holder main part portion 81 is a stepped columnar shape which extends in the axial direction Y about the central axis J. As shown in
An outer diameter of the slide portion 81a is larger than the outer diameter of the large diameter portion 31b. The outer diameter of the slide portion 81a is substantially the same as the inner diameter of the introduction hole portion 23b, and is slightly smaller than the inner diameter of the introduction hole portion 23b. The slide portion 81a can move in the axial direction Y while sliding with respect to the inner peripheral surface of the spool hole 23, that is, the inner peripheral surface of the introduction hole portion 23b in the embodiment. A radial outer edge portion of the rear surface of the slide portion 81a can contact with a stepped surface facing the front side in a step which is generated between the spool hole main part 23a and the introduction hole portion 23b. In this way, the magnet holder 80 can be prevented from moving from a contact position of the magnet holder 80 and the stepped surface to the rear side, and the rearmost position of the magnet holder 80 can be determined. As described later, the spool valve 30 receives a backward force from the elastic member 70 via the magnet holder 80, and thus the rearmost position of the spool valve 30 can be determined by determining the rearmost position of the magnet holder 80.
The supported portion 81b is connected to a rear end portion of the slide portion 81a. An outer diameter of the supported portion 81b is smaller than the outer diameter of the slide portion 81a and the outer diameter of the large diameter portion 31b, and is larger than the outer diameter of the support portion 31a and the outer diameter of the small diameter portion 31c. The supported portion 81b is movable in the spool hole main part 23a. The supported portion 81b moves in the axial direction Y between the introduction hole portion 23b and the spool hole main part 23a along with a movement in the axial direction Y of the spool valve 30.
The supported portion 81b has a supported concave portion 80b which is hollow from the rear end portion of the supported portion 81b toward the front side. The support portion 31a is inserted into the supported concave portion 80b. The front end portion of the support portion 31a contacts with the bottom surface of the supported concave portion 80b. In this way, the magnet holder 80 is supported to the spool valve 30 from the rear side. A dimension in the axial direction Y of the supported portion 81b is, for example, smaller than a dimension in the axial direction Y of the slide portion 81a.
As shown in
The pair of opposite portions 82 are fitted in the pair of groove portions 24. The opposite portions 82 are opposite in the peripheral direction to the inner surfaces 24a of the groove portions 24 and can be brought into contact with the inner surfaces 24a. Besides, in this specification, “certain two parts are opposite in the peripheral direction” includes that both of the two parts are located in a virtual circle along the peripheral direction and are opposite to each other.
As shown in
The magnet holder 80 has a second concave portion 80a which is hollow backward from the front end portion in the magnet holder 80. The second concave portion 80a extends from the slide portion 81a to the supported portion 81b. As shown in
The magnet holder 80 may be made of, for example, resin or metal. When the magnet holder 80 is made of resin, the magnet holder 80 can be easily manufactured. In addition, manufacturing cost of the magnet holder 80 can be reduced. When the magnet holder 80 is made of metal, dimensional accuracy of the magnet holder 80 can be improved.
As shown in
As described above, the slide portion 81a on which the first concave portion 81c is arranged moves while sliding with respect to the inner peripheral surface of the spool hole 23. Therefore, the outer peripheral surface of the slide portion 81a is in contact with the inner peripheral surface of the spool hole 23 or opposite to the inner peripheral surface of the spool hole 23 via a narrow gap. Thus, it is hard for foreign matter such as metal pieces contained in oil to enter the first concave portion 81c. Accordingly, the foreign matter such as metal pieces contained in oil can be prevented from being attached to the magnet 50 accommodated in the first concave portion 81c. When the magnet holder 80 is made of metal, dimensional accuracy of the slide portion 81a can be improved, and thus it is even harder for the foreign matter such as metal pieces contained in oil to enter the first concave portion 81c.
As shown in
In the embodiment, before the upper body 22 and the lower body 21 overlap each other, the fixed member 71 is inserted from the opening portion of the through hole 22b which is open on the lower surface of the upper body 22 to the through hole 22a via the through hole 22b and the introduction hole portion 23b. Then, as shown in
As shown in
The rear end portion of the elastic member 70 contacts with the bottom surface of the second concave portion 80a. The front end portion of the elastic member 70 contacts with the fixed member 71. In this way, the front end portion of the elastic member 70 is supported by the fixed member 71. The fixed member 71 receives a forward elastic force from the elastic member 70, and the extension portion 71a is pressed to the front inner surfaces of the through holes 22a, 22b.
By supporting the front end portion of the elastic member 70 by the fixed member 71, the elastic member 70 applies a backward elastic force to the spool valve 30 via the magnet holder 80. Therefore, for example, at a position in which an oil pressure of oil or a force applied from a driving device such as a solenoid actuator which is applied to the rear end portion of the spool valve 30 counterbalances the elastic force of the elastic member 70, the position in the axial direction Y of the spool valve 30 can be maintained. In this way, by changing the force applied to the rear end portion of the spool valve 30, the position in the axial direction Y of the spool valve 30 can be changed, and opening and closing of the oil passage 10a in the oil passage body 20 can be switched.
In addition, by the oil pressure of oil or the force applied from a driving device such as a solenoid actuator which is applied to the rear end portion of the spool valve 30 and the elastic force of the elastic member 70, the magnet holder 80 and the spool valve 30 can be pressed to each other in the axial direction Y. Therefore, the magnet holder 80 moves in the axial direction Y along with the movement in the axial direction Y of the spool valve 30 while a relative rotation around the central axis with respect to the spool valve 30 is allowed.
The sensor module 40 has a housing 42 and a magnetic sensor 41. The housing 42 accommodates the magnetic sensor 41. As shown in
As shown in
When the position in the axial direction Y of the magnet 50 is changed along with the movement in the axial direction Y of the spool valve 30, the magnetic field of the magnet 50 passing through the magnetic sensor 41 is changed. Therefore, by detecting the change of the magnetic field of the magnet 50 by the magnetic sensor 41, the position in the axial direction Y of the magnet 50, that is, the position in the axial direction Y of the magnet holder 80 can be detected. As described above, the magnet holder 80 moves in the axial direction Y along with the movement in the axial direction Y of the spool valve 30. Therefore, by detecting the position in the axial direction Y of the magnet holder 80, the position in the axial direction Y of the spool valve 30 can be detected.
The magnetic sensor 41 overlaps the magnet 50 in the up-down direction Z. That is, as least a part of the magnet 50 overlaps the magnetic sensor 41 in a direction parallel to the up-down direction Z within the radial directions. Therefore, the magnetic field of the magnet 50 is easily detected by the magnetic sensor 41. Accordingly, by the sensor module 40, a displacement in the axial direction Y of the magnet holder 80, that is, a displacement in the axial direction Y of the spool valve 30 can be detected more accurately.
Besides, in this specification, “at least a part of the magnet overlaps the magnetic sensor in the radial direction” means that at least a part of the magnet may overlap the magnetic sensor in the radial direction in at least some positions within a range in which the spool valve to which the magnet is directly fixed moves in the axial direction. That is, for example, when the spool valve 30 and the magnet holder 80 displace in the axial direction Y from the position in
The pressure control device 10 further includes a rotation stop portion. The rotation stop portion is a part capable of contacting with the magnet holder 80. In the embodiment, the rotation stop portion is the inner surfaces 24a of the groove portions 24. That is, the opposite portions 82 are opposite in the peripheral direction to the inner surfaces 24a serving as rotation stop portions and can contact with the inner surfaces 24a.
Therefore, according to the embodiment, for example, when the opposite portions 82 are about to rotate around the central axis J, the opposite portions 82 contact with the inner surfaces 24a serving as rotation stop portions. In this way, rotation of the opposite portions 82 is suppressed by the inner surfaces 24a, and the magnet holder 80 is suppressed from rotating around the central axis J. Accordingly, the magnet 50 fixed to the magnet holder 80 can be suppressed from being misaligned in the peripheral direction. Therefore, when the position in the axial direction Y of the spool valve 30 is not changed, position information in the axial direction Y of the magnet 50 detected by the magnetic sensor 41 can be suppressed from being changed even if the spool valve 30 rotates around the central axis J. In this way, position information of the spool valve 30 can be suppressed from being changed, and an accuracy of grasping the position in the axial direction Y of the spool valve 30 can be improved.
In addition, according to the embodiment, the rotation stop portion is the inner surfaces 24a of the groove portions 24. Therefore, it is possible not to prepare another member as a rotation stop portion, and the number of components of the pressure control device 10 can be reduced. In this way, time and labor required for the assembly of the pressure control device 10 and manufacturing cost of the pressure control device 10 can be reduced.
As described above, there is a case that oil passing through the pressure control device 10 contains foreign matter such as metal pieces and the like. Such foreign matter may be captured in a process that oil passes through the pressure control device 10, and may be prevented from further flowing to the downstream side. Thus, the pressure control device 10 is configured to be capable of capturing foreign matter. In the following, this configuration and action are described with reference to
Besides, in the embodiment, the pressure control device 10 is applied in, but not limited to, the oil pressure control device for controlling oil pressure. A device to which the pressure control device 10 is applicable includes, in addition to the oil pressure control device, for example, a water pressure control device for controlling water pressure, an air pressure control device for controlling air pressure and the like. In this case, the substance passing through the pressure control device 10 is a fluid such as oil, water, air and the like, and the following description is given with these fluids being collectively referred to as a “fluid Q”.
As shown in
The body 3 can be at least one of the lower body 21 and the upper body 22 constituting the oil passage body 20. As shown in
The groove 31 has a bottom portion (a first bottom portion) 311, a side wall portion 312 located on the left side of the bottom portion 311, and a side wall portion 313 located on the right side of the bottom portion 311. Besides, a boundary portion 314 between the bottom portion 311 and the side wall portion 312 and a boundary portion 315 between the bottom portion 311 and the side wall portion 313 may be rounded as shown in
The groove 31 has, but not limited to, a linear shape along the axial direction Y in a plan view of the body 3, and may has a part that at least partially bends. A width (a first width) W31 (see
The widening portion 32 is arranged in a longitudinal direction of the groove 31, that is, in the middle of the axial direction Y. The width of the widening portion 32 is larger than the width W31 of the groove 31 from the surface 301 to the bottom portion 311, and the widening portion 32 functions as an accommodation portion in which the cylindrical filter unit 9 is accommodated. The width W32 (see
The widening portion 32 having such a shape can be processed using an end mill for example.
As shown in
As shown in
The filter unit 9 has a cylindrical frame body 92 and a flat-plate-shaped filter member 93 disposed on the inside of the frame body 92.
The filter member 93 is disposed along a central axis O92 of the frame body 92, and a thickness direction of the filter member 93 is parallel to the axial direction Y. In this way, the filter member 93 can face the fluid Q passing through the flow path 33.
The filter member 93 has multiple small pores 931 which penetrate in the thickness direction of the filter member 93. These small pores 931 are spaced and disposed along both the left-right direction X and the up-down direction Z. In addition, the size of each small pore 931 is substantially a size to a degree of preventing the passing of the foreign matter and not obstructing the flow of the fluid Q. The specific size of each small pore 931 may be 0.1-0.5 mm, or 0.3-0.4 mm, in diameter. In addition, the total area of the small pores 931 may be 10-20 mm2, or 12-13 mm2. By such small pores 931, the capability of the filter unit 9 to capture foreign matter is improved.
In addition, the filter member 93 is supported on the inside of the frame body 92. In this way, when the fluid Q passes through the filter member 93, the filter member 93 is prevented from deforming due to the flow of the fluid Q, and thus foreign matter can be reliably captured by the filter member 93. As a result, the capability of the filter unit 9 to capture foreign matter is further improved.
As shown in
As shown in
Then, the filter member 93 covers the through hole portion 921 to be disposed along the central axis of the frame body 92. In this way, the filter member 93 and the frame body 92 are unitized and configured as one component, that is, the filter unit 9.
When the body 3 and the filter unit 9 are assembled, the assembly can be performed by simple work of inserting the filter unit 9 into the widening portion 32. In addition, as described above, the widening portion 32 is wider than the groove 31. In this way, the insertion of the filter unit 9 into the widening portion 32 can be performed easily regardless of the width W31 of the groove 31, and thus workability during the assembly of the body 3 and the filter unit 9 is improved.
As shown in
As shown in
In addition, the cylindrical frame body 92 has a blocking wall portion 923 which blocks the upper side in the central axis O92, and a blocking wall portion 924 which blocks the lower side. In a state that the filter unit 9 is accommodated in the widening portion 32, a lower portion (a part) of the filter unit 9, that is, the blocking wall portion 924 within the blocking wall portion 923 and the blocking wall portion 924 can enter the reception portion 34.
For such a configuration, for example, when the reception portion 34 is omitted from the widening portion 32, the bottom portion of the widening portion 32 and the bottom portion 311 of the groove 31 have the same height and are in succession. Then, it is likely that a small gap is generated between the bottom portion of the widening portion 32 and an end surface 924a of the blocking wall portion 924 when the filter unit 9 is accommodated in the widening portion 32. A flow passing through the gap may be generated in the fluid Q; in this case, the foreign matter flows to the downstream side across the filter unit 9 instead of being captured by the filter unit 9.
As described above, the pressure control device 10 is configured in a manner that the blocking wall portion 924 of the filter unit 9 enters the reception portion 34 of the widening portion 32. In other words, in the pressure control device 10, a step 331 is generated in a space (a boundary) between the bottom portion 311 of the groove 31 and the bottom surface 341 of the reception portion 34, and the blocking wall portion 924 is disposed to eliminate the step 331. In this way, it is substantially difficult to generate a flow of the fluid Q flowing around the space between the blocking wall portion 924 and the reception portion 34, and thus the foreign matter can be prevented from flowing to the downstream side across the filter unit 9. In addition, even if a gap is generated between the blocking wall portion 924 and the reception portion 34, the size of this gap can be suppressed to 0.4 mm or less.
A thickness T924 of the blocking wall portion 924 is the same as the depth D34 of the reception portion 34. For example, a step is generated between the bottom portion 311 of the groove 31 and the blocking wall portion 924 when the thickness T924 and the depth D34 are different, and it is likely that the smooth passing of the fluid Q through the filter unit 9 is obstructed due to the size of this step. In the pressure control device 10, the thickness T924 and the depth D34 are the same and thereby the step can be eliminated, and thus the fluid Q can smoothly pass through the filter unit 9. In addition, because the fluid Q can pass smoothly, it is more difficult to generate a flow of the fluid Q flowing around the space between the blocking wall portion 924 and the reception portion 34. In this way, the foreign matter can be more reliably prevented from flowing to the downstream side across the filter unit 9.
As shown in
As shown in
Besides, the defining portion 95 may not have a pair of projection portions 951; for example, one projection portion 951 may be omitted.
In addition, a width W951 of each projection portion 951 may be a little smaller than the width W31 of the groove 31.
Then, each projection portion 951 is disposed in the groove 31 in a state that the filter unit 9 is accommodated in the widening portion 32. In addition, at this time, each projection portion 951 may also be in contact with at least one of the side wall portion 312 and the side wall portion 313 of the groove 31. By such projection portions 951, the disposition direction with respect to the groove 31 is properly defined in a state that the filter unit 9 is accommodated in the widening portion 32, and thus the rotation around the central axis O92 is prevented. In this way, regardless of the flow of the fluid Q, the filter member 93 can be opposite to the flow direction of the fluid Q, and thus the foreign matter can be captured stably.
In addition, the defining portion 95 can be configured by the projection portion 951 having a simple shape and thus contributes to high efficiency during the manufacturing of the filter unit 9.
In addition, by arranging the defining portion 95 in the blocking wall portion 923 of the frame body 92, the defining portion 95 can be disposed toward the corner of the flow path 33 as much as possible, and thus the defining portion 95 can be prevented or suppressed from obstructing the flow of the fluid Q.
As shown in
In the filter unit 9 with the above configuration, for example, the frame body 92 may be made of resin, and the filter member 93 may be made of metal. In this way, the filter unit 9 can be used as an insert molded article of the frame body 92 and the filter member 93. In this way, high efficiency during the manufacturing of the filter unit 9 can be achieved. Particularly, the frame body 92 has a cylindrical shape and thereby the filter unit 9 is formed easily.
In the following, a second embodiment of the pressure control device of the disclosure is described with reference to
This embodiment is similar to the first embodiment except that the configuration of the detachment prevention portion is different.
As shown in
Each elastic sheet 941 is disposed parallel to the up-down direction Z and is supported at both ends. In addition, each elastic sheet 941 arches in a natural state that no external force is applied, that is, in a state that the filter unit 9 is not yet accommodated in the widening portion 32. In this way, each elastic sheet 941 deforms easily when an external force is applied. In addition, each elastic sheet 941 closely adheres to the widening portion 32 after deforming and can prevent the filter unit 9 from being detached from the flow path 33.
In addition, each elastic sheet 941 is disposed parallel to the up-down direction Z in the outer periphery portion 922 of the frame body 92 and arches, and thereby when an operation of inserting the filter unit 9 toward the lower side of the up-down direction Z into the widening portion 32 is performed, this elastic sheet 941 can be prevented from obstructing the operation.
As shown in
In the following, a third embodiment of the pressure control device of the disclosure is described with reference to
This embodiment is similar to the first embodiment except that the configuration of the defining portion is different.
As shown in
By such a non-circular portion 952, the filter unit 9 is prevented from rotating around the central axis O92 in a state of being accommodated in the widening portion 32, and thus the foreign matter can be stably and reliably captured by the filter member 93.
In addition, the defining portion 95 can be configured by the projection portion 952 having a simple shape and thus contributes to high efficiency during the manufacturing of the filter unit 9.
In the following, a fourth embodiment of the pressure control device of the disclosure is described with reference to
This embodiment is similar to the first embodiment except that the shape of the defining portion is different.
As shown in
By such a non-circular portion 953, the filter unit 9 is prevented from rotating around the central axis O92 in a state of being accommodated in the widening portion 32, and thus the foreign matter can be stably and reliably captured by the filter member 93.
In addition, the defining portion 95 can be configured by the projection portion 953 having a simple shape and thus contributes to high efficiency during the manufacturing of the filter unit 9.
In addition, since the non-circular portion 953 has a rounded shape in a plan view, compared with the non-circular portion 952 having a square shape for example, when the work of inserting the filter unit 9 into the widening portion 32 is performed, the non-circular portion 953 contributes to easy and quick completion of this work.
The illustrated embodiments of the pressure control device of the disclosure are described above, but the disclosure is not limited hereto, and each portion constituting the pressure control device can be replaced with a portion having any configuration that can perform similar functions. In addition, any composition may be added.
In addition, the pressure control device of the disclosure may combine optional two or more configurations (features) in the above-described embodiments.
In addition, the filter member is disposed along the central axis of the frame body in the above-described embodiments, but the disclosure is not limited hereto. For example, the filter member may be disposed to be curved into an arch shape, or be disposed to bend into a doglegged shape. In addition, the flat-plate-shaped filter member may be disposed at an angle to the central axis of the frame body.
Number | Date | Country | Kind |
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2018-158898 | Aug 2018 | JP | national |