JP2005254103A - Spin-on filter - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a spin-on filter sufficiently securing a flow path of a fluid to be filtered and having a small pressure loss. <P>SOLUTION: In the spin-on filter 1, an element assembly body 3 includes a compressed coil spring 65 between the bottom face of a case 30 and the lower end face of a filter element 50. When a filter head 2 is clear of the element assembly body 3, the upper end face of the filter element 50 energizes a cover member 34 by the compressed coil spring 65, thus outer peripheral space 71 is so constituted as not to communicate with through-space 36 formed in the cover member 34. Then, when the element assembly body 3 is attached to the filter head 2, the filter element 50 is pushed downward against the case 30 by the filter head 2, and the upper end face of the filter element 50 and the cover member 34 come apart from and together with each other, thus the outer peripheral space 71 is constituted so as to communicate with an inflow hole 8 of the filter head 2 helically inserted into the through-space 36. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a filter used for filtering a fluid such as oil, and more particularly to a single-use type filter called a so-called spin-on filter.

  Spin-on filters have been conventionally used in various ways as engine oil filters and the like. This conventional spin-on filter (element assembly) has a disk-shaped cover in which a filter element is disposed in a cylindrical case having an upper end opened and a lower end closed, and a plurality of holes described later are formed in the case opening. The element assembly to which the members are joined is configured to be detachable and replaceable with a filter head fixed to the vehicle body or the engine (see, for example, Patent Document 1).

JP-A-5-96107

  The cover member constituting the element assembly is provided with an internal communication hole communicating with the inner peripheral space of the filter element, an outer peripheral surface of the filter element, and a case in order to provide a flow path for a fluid (such as hydraulic oil) to be filtered. An external communication hole communicating with the outer peripheral space constituted by the inner peripheral surface is formed. However, since the external communication hole is formed in the peripheral portion of the cover member, the diameter is reduced due to restrictions on the position and the like. Therefore, since the pressure loss of the fluid filtered by the spin-on filter increases, there is a problem that the oil pump for flowing hydraulic oil to the spin-on filter also needs to increase its output.

  The present invention has been made in view of such a problem, and an object of the present invention is to provide a spin-on filter that ensures a sufficient flow path for a fluid to be filtered and has a small pressure loss.

  In order to solve the above problems, a spin-on filter according to the present invention includes a filter head having an inflow hole and an outflow hole, and a filter element in a substantially cylindrical case having an upper end opened and a lower end closed. It is composed of an element assembly that is built in and screwed onto the filter head. A double cylindrical outer cylindrical portion and an inner cylindrical portion projecting downward are provided on the lower surface of the filter head, and are formed in an outer passage and an inner cylindrical portion formed between the outer cylindrical portion and the inner cylindrical portion. Each of the inner passages communicates with one of the inflow hole and the outflow hole. Further, when the element assembly has an elastic member (for example, the compression coil spring 65 in the embodiment) between the bottom surface of the case and the lower end surface of the filter element, and the element assembly is removed from the filter head, The upper end surface of the filter element is urged by the elastic member toward the opening of the case (for example, the cover member 34 in the embodiment), and the outer peripheral space formed between the outer peripheral surface of the filter element and the inner peripheral surface of the case is opened. Configured to be separated from the portion. Then, when the element assembly is attached to the filter head by screwing the male screw part formed on the outer peripheral surface of the outer cylindrical part and the female screw part formed on the opening, the inner cylindrical part is filtered. It is formed on the upper end surface of the element and is fitted with a communication hole that communicates with the inner peripheral space of the filter element so that the inner passage communicates with the inner peripheral space. When pressed down, the upper end surface of the filter element and the opening of the case are separated from each other so that the outer peripheral space and the outer passage screwed into the opening communicate with each other.

  At this time, a seal member (for example, the second seal ring 55 in the embodiment) surrounding the communication hole and having an inner diameter smaller than the communication hole is disposed on the upper end surface of the filter element, and the element assembly is attached to the filter head. It is preferable that the sealing member abuts on the outer peripheral surface of the inner cylindrical portion to separate the inner peripheral space and the outer peripheral space.

  Alternatively, the inner cylindrical portion is composed of a distal end portion inserted into the communication hole of the filter element and a base end portion having a diameter larger than the distal end portion, and the upper end surface of the filter element protrudes upward and surrounds the communication hole. When the seal member (for example, the second seal ring 55 'in the embodiment) is disposed and the element assembly is attached to the filter head, the seal member is attached to the lower surface of the base end (for example, the filter engagement in the embodiment). Preferably, the inner space and the outer space are separated from each other in contact with the portion 6c).

  In addition, the filter element has a bottomed valve case in which the inner space communicates with the communication hole and protrudes into the inner peripheral space, and a valve side opening is provided on the side surface, and the valve element is slidably arranged vertically in the valve case. And a valve body that is urged to the communication hole by the second elastic member (for example, the valve spring 59 in the embodiment) and closes the communication hole when the element assembly is removed from the filter head. When the element assembly is attached to the filter head on the side surface of the tip of the inner cylindrical portion, a head side opening that is aligned with the valve side opening is provided, and the element assembly is attached to the filter head In addition, the valve body is pushed downward by the inner cylindrical portion so that the valve side opening and the head side opening communicate with each other and the inner passage and the inner circumferential space communicate with each other. Door is preferable.

  Furthermore, it is preferable to provide an inflow valve and an outflow valve that are opened when a predetermined pressure is applied to the outer passage and the inner passage.

  In such a spin-on filter, the case is composed of a substantially cylindrical case main body having an upper end opened and a lower end closed, and a cover member attached to the case main body so as to cover the upper end opening. It is preferable that when the solid body is removed from the filter head, the upper end portion of the filter element is urged to the lower end portion of the cover member so that the outer peripheral space and the opening portion are separated.

  When the spin-on filter according to the present invention is configured as described above, when the element assembly is attached to the filter head, the filter element is pushed downward by the inner cylindrical portion and separated from the opening (cover member) of the case. A sufficient space connecting the outer peripheral space in the case and the outer passage of the filter head is formed and can function as a filter. Moreover, this space can reduce the pressure loss of the fluid flowing into the spin-on filter. Further, when the element assembly is removed from the filter head, the filter element comes into contact with the opening (cover member) of the case, and the opening and the outer peripheral space are separated, so that the removed element assembly is moved to the outer peripheral space. The remaining fluid can be prevented from flowing out directly from the outer peripheral space through the opening.

  Further, by providing a valve in the communication hole of the filter element, the communication hole is blocked when the element assembly is removed from the filter head, and the fluid remaining in the inner circumferential space is prevented from flowing out to the outside. be able to. At this time, by providing an inflow valve and an outflow valve also in the outer passage and the inner passage of the filter head, it is possible to prevent fluid from flowing out from the outer passage and the inner passage when the element assembly is removed from the filter head. Can do.

  Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings. As shown in FIG. 1, the spin-on filter (hereinafter referred to as “filter 1”) includes a filter head 2 and an element assembly 3 that is detachably screw-attached to the filter head 2. The For example, the filter head 2 is fixed to a hydraulic device or the like, and the element assembly 3 is removed from the filter head 2 and replaced with a new element assembly 3 as necessary. A specific configuration will be described below.

  First, the filter 1 according to the first embodiment will be described with reference to FIGS. The filter 1 includes a filter head 2 and an element assembly 3 that is detachably attached to the filter head 2. The lower surface of the filter head 2 has an outer cylindrical portion 5 and an inner cylindrical portion 6 that protrude downward and are formed in a double cylindrical shape. For this reason, a ring-shaped outer passage 7 extending in the vertical direction is formed between the inner peripheral surface of the outer cylindrical portion 5 and the outer peripheral surface of the inner cylindrical portion 6, and the upper portion of the outer passage 7 is formed outside the filter 1. It communicates with the inflow hole 8 that communicates, and the lower part is open. Further, a cylindrical inner passage 9 is formed which is surrounded by the inner peripheral surface of the inner cylindrical portion 6 and extends vertically, and communicates with an outflow hole 10 communicating with the outside of the filter 1 in the upper portion, and the lower portion is opened. Yes.

  The inner cylindrical portion 6 includes a proximal end portion 6a and a distal end portion 6b extending downward and having a diameter smaller than that of the proximal end portion 6a. Further, the inner cylindrical portion 6 is formed so that the amount of protrusion below the outer cylindrical portion 5 is larger. A filter engaging portion 6c that abuts a filter element 50 (to be described later) and restricts upward movement is provided on the lower surface of the base end portion 6a of the inner cylindrical portion 6 (stepped portion between the base end portion 6a and the tip end portion 6b). Is formed. Further, a male screw portion 5 a is formed on the outer peripheral surface of the outer cylindrical portion 5. A first seal surface 11 with which a first seal ring 38 to be described later comes into contact with the lower surface of the filter head 2 located on the outer peripheral side of the outer cylindrical portion 5 when the element assembly 3 is attached to the filter head 2. Is formed.

  On the other hand, the element assembly 3 includes a case 30 and a filter element 50 inserted and held in the case 30. The case 30 has a cylindrical case body 31 with an upper end 32 opened and a lower end 33 closed, a cover member 34 attached to cover the upper end opening of the case body 31, and the cover member 34. And a ring-shaped cover fixing member 35 that fixes the cover member 34 to the case main body 31. The cover member 34 and the cover fixing member 35 are coupled by, for example, spot welding. Further, as shown in FIG. 1, the cover fixing member 35 and the case main body 31 are joined by bending their distal ends integrally in the outer peripheral direction. The cover fixing member 35 is formed with a ring-shaped first seal mounting groove 37 so as to surround the opening of the case 30, and a ring-shaped first seal ring 38 is formed in the first seal mounting groove 37. The upper end of the case body 31 protrudes upward and is held.

  The cover member 34 includes a ring-shaped disk part 34a and a cylindrical coupling part 34b extending downward from the inner periphery of the disk part 34a, and is surrounded by the inner peripheral surface of the coupling part 34b. A through space 36 penetrating vertically is formed. A female screw portion 34c that is screwed with the male screw portion 5a of the filter head 2 is formed on the inner peripheral surface of the coupling portion 34b. For this reason, the element assembly 3 can be attached to the filter head 2 (spin-on) while rotating the element assembly 3 such that the female screw portion 34 c is screwed with the male screw portion 5 a of the outer cylindrical portion 5.

  The filter element 50 includes a filter medium 54 having a cross-sectional shape of chrysanthemum and an outer shape that is substantially cylindrical by joining ends of the filter medium folded in a bellows shape. The inner peripheral portion is supported by a cylindrical center tube 53. The center tube 53 is made of a punch sheet or the like having a large number of small holes 53a, and the working oil filtered through the filter medium 54 passes through the small holes 53a and is an inner peripheral space that is an internal space thereof. 72 is configured to flow into 72.

  A compression coil spring 65 is disposed at the bottom of the case 30, and the filter element 50 is pushed upward by the compression coil spring 65. For this reason, the upper end surface of the filter element 50 (the upper surface 51a of the upper end plate 51) is urged toward the lower end portion of the cover member 34 (the lower end portion of the coupling portion 34b). Retained. When the filter element 50 is held in this way, the upper end plate 51 allows the outer space 71 surrounded by the inner peripheral surface of the case body 31 and the outer peripheral surface of the filter element 50 and the through space formed in the cover member 34. 36 is separated.

  The upper end plate 51 of the filter element 50 has a diameter smaller than the inner diameter of the coupling portion 34 b constituting the cover member 34 at the center thereof, and substantially the same as the outer diameter of the tip portion 6 b constituting the inner cylindrical portion 6. A cylindrical communication hole 51b that penetrates vertically with a large inner diameter is formed. In the state where the filter element 50 is held in the case 30 as described above, the communication hole 51b is a connecting portion of the cover member 34. It opposes 34b (penetration space 36). Therefore, in a state before the element assembly 3 is attached to the filter head 2 (single unit state), the inner peripheral space 72 in the center tube 53 communicates with the through space 36 through the communication hole 51b. A second seal ring 55 is sandwiched between the upper end plate 51 and the seal holding member 56 attached to the upper surface 51 a of the upper end plate 51 so as to surround the communication hole 51 b on the upper surface 51 a of the upper end plate 51. ing. The seal holding member 56 is provided with an opening having a diameter substantially the same as the inner diameter of the communication hole 51b, and is aligned with the communication hole 51b in plan view. Further, the inner diameter of the second seal ring 55 is formed slightly smaller than the inner diameter of the communication hole 51b, and the second seal ring 55 protrudes inward from the communication hole 51b and is held in plan view.

  In order to attach the element assembly 3 configured in this way to the filter head 2, if it is disposed below the filter head 2, the lower end of the male screw portion 5a and the upper end of the female screw portion 34c are as shown in FIG. Further, the tip 6b of the inner cylindrical portion 6 is inserted and fitted into the communication hole 51b of the upper end plate 51, and the upper end of the seal holding member 56 and the filter engaging portion 6c of the inner cylindrical portion 6 abut. . Also at this time, as is apparent from FIG. 2, the through space 36 and the outer peripheral space 71 are separated by the cover member 34 and the upper end plate 51 contacting each other.

  When the element assembly 3 is attached to the filter head 2 while rotating the male screw portion 5a and the female screw portion 34c, as shown in FIG. 5 and the inner cylindrical portion 6) are screwed into the through space 36 of the cover member 34, and the case 30 moves upward with respect to the filter head 2, but the filter element 50 is moved upward by the filter engaging portion 6c. Therefore, the compression coil spring 65 is compressed and moved downward with respect to the case 30. Therefore, since the lower end of the cover member 34 and the upper end plate 51 are separated, an inflow space 73 is formed therebetween. The outer passage 7 of the outer cylindrical portion 5 screwed into the through space 36 communicates with the outer peripheral space 71 through the inflow space 73. On the other hand, the inner passage 9 of the inner cylindrical portion 6 inserted into the communication hole 51 b communicates with the inner peripheral space 72. At this time, since the second seal ring 55 contacts the outer peripheral surface of the inner cylindrical portion 6 (tip portion 6b), the inflow space 73 (the outer peripheral space 71) and the inner peripheral space 72 are sealed. Further, since the upper surface of the first seal ring 38 contacts the first seal surface 11, the inflow space 73 (outer peripheral space 71) is sealed with respect to the outside of the filter 1.

  The filtration of hydraulic oil by the filter 1 configured as described above will be briefly described with reference to FIG. The hydraulic oil to be filtered discharged from an oil pump or the like is fed into the outer passage 7 from the inflow hole 8 and flows into the outer peripheral space 71 through the inflow space 73 as indicated by an arrow IN. The hydraulic oil that has flowed into the outer peripheral space 71 passes through the filter medium 54 of the filter element 50, and solids and the like contained in the hydraulic oil are captured and filtered, and the inner peripheral space 72 passes through the small hole 53 a of the center tube 53. Flow into. The hydraulic fluid that has flowed into the inner peripheral space 72 is in a clean state, and flows out from the outflow hole 10 to the outside through the inner passage 9 as indicated by an arrow OUT. Thus, when the element assembly 3 is attached to the filter head 2, the inflow space 73 is formed, so that a sufficient space is formed between the outer passage 7 and the outer peripheral space 71, so that it can function as a filter. it can. Further, the inflow space 71 can reduce the pressure loss applied to the fluid flowing into the filter 1.

  In the above embodiment, in order to seal the inner peripheral space 72 and the inflow space 73, the second seal ring 55 is provided on the outer peripheral surface of the inner cylindrical portion 6 inserted into the inner peripheral space 72 of the filter element 50. Although the case where it is configured to abut is described, sealing at another position is also possible. For example, as shown in FIG. 4, a second seal groove 51c is formed in the upper end plate 51 so as to surround the communication hole 51b, and the second seal groove 51c protrudes above the upper surface 51a of the upper end plate 51. In this manner, the second seal ring 55 ′ can be arranged. When the second seal ring 55 ′ is arranged in this manner, as shown in FIG. 5, the second seal ring 55 ′ comes into contact with the filter engaging portion 6 c of the inner cylindrical portion 6, and the inner peripheral space 72 and The inflow space 73 can be sealed.

  In addition, as shown in FIG. 6, the case body 31 and the cover member 34 are joined to each other by forming a protruding portion 34 d that protrudes in a disk shape on the outer periphery of the cover member 34, and a ring on the upper portion thereof. After the cover member 34 is inserted into the upper end opening of the case main body 31, the upper end portion 32 of the case main body 31 is press-formed inward and enters the ring-shaped groove 39. By doing so, the cover member 34 can be firmly coupled to the upper end portion of the case main body 31. At this time, a third seal groove 34e is formed on the outer periphery of the projecting portion 34d so that the internal hydraulic fluid does not flow out between the case main body 31 and the cover member 34 so as to project outward from the projecting portion 34d. A third seal ring ring 40 is provided. The first seal ring 38 disposed so that hydraulic fluid does not flow out from between the filter head 2 and the element assembly 3 when the element assembly 3 is attached to the filter head 2 is shown in FIG. As shown in FIG. 3, a first seal groove 34f is formed on the inner peripheral surface of the upper end side of the cover member 34 (corresponding to the portion forming the through space 36 in the above description), and the inside of the through space 36 is formed in the first seal groove 34f. It is also possible to arrange a first seal ring 38 'so as to protrude to the outer peripheral surface of the outer cylindrical portion 5 and to seal it by contacting the outer peripheral surface of the outer cylindrical portion 5 (upper portion of the male screw portion 5a) as shown in FIG. .

  According to the above configuration, when the element assembly 3 is replaced, when the element assembly 3 is removed from the filter head 2, the filter element 50 is pushed upward by the biasing force of the coil spring 36, and the upper end plate 51. And the cover member 34 are in contact with each other, and the hydraulic oil in the outer peripheral space 71 does not flow out through the through space 36 and can be replaced without contaminating the surroundings with the hydraulic oil.

  However, in the filter 1 according to the first embodiment described above, since the element assembly 3 may be filled with the working oil in the inner circumferential space 72 as well, it passes from the through space 36 through the communication hole 51b. There is a possibility that hydraulic fluid will flow out. A second embodiment that solves such problems will be described below.

  The filter 100 according to the second embodiment will be described with reference to FIGS. In this figure, parts having the same functions as those in the first embodiment are denoted by the same reference numerals, and description thereof is omitted. As described in the first embodiment, the hydraulic oil in the outer circumferential space 71 is configured so that the cover member 34 and the upper end plate 51 come into contact with each other and do not flow outside. Therefore, in this second embodiment, the filter element 50 The communication hole 51b is provided with a valve 57 so that the hydraulic oil in the inner circumferential space 72 does not flow out of the communication hole 51b. As shown in FIG. 8, the valve 57 has a bottomed cylindrical bowl-shaped valve case 57a attached to the lower surface of the upper end plate 51 so as to cover the communication hole 51b, and substantially the same inner diameter as the valve case 57a. A valve body 58 that is slidably arranged in the valve case 57a in a shape and a valve spring 59 that is disposed between the valve body 58 and the bottom surface of the valve case 57a and pushes up the valve body 58 upward. Composed. By this valve spring 59, the valve body 58 is urged toward the lower end portion of the communication hole 51b located in the valve case 57a, the upward movement is restricted, and the communication hole 51b is blocked. A plurality of valve side openings 57b are formed on the lower side surface of this valve case 57a (below the valve body 58 biased to the lower end of the communication hole 51b) as shown in FIG. When 58 is pushed down, the inner circumferential space 72 and the communication hole 51b are communicated.

  On the other hand, a head-side opening 6d is also formed on the side surface of the distal end portion 6b of the inner cylindrical portion 6 of the filter head 2, and the element assembly 3 is attached to the filter head 2 as shown in FIGS. 9 and 10B. When attached, the valve body 58 is pushed downward by the inner cylindrical portion 6 (tip portion 6b) inserted into the communication hole 51b, and the head side opening 6d and the valve side opening 57b are aligned to form an inner circumferential space. 72 and the inner passage 9 are communicated with each other. For example, a guide groove (not shown) is provided on the side surface of the inner cylindrical portion 6 so that the head side opening 6d and the valve side opening 57b are aligned when the element assembly 3 is attached to the filter head 2. When the element assembly 3 is attached, the filter element 50 is rotated by the guide groove so that the head side opening 6d and the valve side opening 57b are aligned.

  As described above, when the element assembly 3 is detached from the filter head 2, the communication hole 51 b is closed by the valve body 58 of the valve 57, so that the hydraulic oil in the inner circumferential space 72 flows out to the outside. The element assembly 3 can be exchanged without contaminating the periphery of the filter 100 with hydraulic oil.

  With the above configuration, the hydraulic oil can be prevented from flowing out from the element assembly 3, but the hydraulic oil remaining in the outer passage 7 and the inner passage 9 of the filter head 2 flows downward and is surrounded by There is a risk of fouling. Therefore, as shown in FIG. 8, by providing an inflow valve 12 and an outflow valve 13 having elasticity that opens only when a predetermined oil pressure is applied, the outer passage 7 and the inner passage 9 of the filter head 2 are provided. The outflow of hydraulic oil from the head 2 can also be prevented.

  As described above, according to the filters 1 and 100 according to the first and second embodiments, when the element assembly 3 is attached to the filter head 2, the inflow space 73 is formed. A sufficient space (inflow space 73) is formed between the outer peripheral space 71 and the pressure loss applied to the fluid flowing into the filters 1 and 100 can be reduced. Furthermore, when the element assembly 3 is removed from the filter head 2, it is possible to prevent the hydraulic oil remaining inside from flowing out to the outside with a simple configuration. In addition, the surroundings are not soiled by the spilled hydraulic oil. In the above embodiment, a case has been described in which the hydraulic oil is filtered by passing from the outer side (outer peripheral space 71) to the inner side (inner peripheral space 72) of the filter element 50. It can also be configured to flow in the direction and filter.

In the spin-on filter which concerns on 1st Example, it is a figure which shows the state which removed the element assembly from the filter head. In the spin-on filter which concerns on 1st Example, it is a figure which shows the state in the middle of attaching an element assembly to a filter head. In the spin-on filter which concerns on 1st Example, it is a figure which shows the state which attached the element assembly to the filter head. It is a figure which shows another form of a 2nd seal ring, and is a figure which shows the state which removed the element assembly from the filter head. It is a figure which shows another form of a 2nd seal ring, and is a figure which shows the state which attached the element assembly to the filter head. It is a figure which shows another form of a cover member, and is a figure which shows the state which removed the element assembly from the filter head. It is a figure which shows another form of a cover member, and is a figure which shows the state which attached the element assembly to the filter head. In the spin-on filter which concerns on 2nd Example, it is a figure which shows the state which removed the element assembly from the filter head. In the spin-on filter which concerns on 2nd Example, it is a figure which shows the state which attached the element assembly to the filter head. It is a figure which shows the valve | bulb provided in a filter element, (A) is a side view, (B) is sectional drawing at the time of an element assembly being attached to the filter head.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1,100 Spin-on filter 2 Filter head 3 Element assembly 5 Outer cylindrical part 5a Male thread part 6 Inner cylindrical part 7 Outer passage 8 Inflow hole 9 Inner passage 10 Outflow hole 30 Case 34 Cover member 34c Female thread part 36 Through space 50 Filter Element 65 Compression coil spring 71 Outer peripheral space 72 Inner peripheral space

Claims (6)

A filter head having an inflow hole and an outflow hole, and an element set that is built in a substantially cylindrical case having an upper end opened and a lower end closed, and is screwed onto the filter head. A spin-on filter consisting of a solid,
A double cylindrical outer cylindrical portion and an inner cylindrical portion projecting downward are provided on the lower surface of the filter head, and an outer passage formed between the outer cylindrical portion and the inner cylindrical portion, and the inner cylindrical portion. The formed inner passages communicate with one of the inflow hole and the outflow hole, respectively.
The element assembly has an elastic member between a bottom surface of the case and a lower end surface of the filter element;
When the element assembly is detached from the filter head, the upper end surface of the filter element is urged by the elastic member toward the opening of the case, and the outer peripheral surface of the filter element and the inner peripheral surface of the case And the outer peripheral space formed between is configured to be separated from the opening,
When the element assembly is attached to the filter head by screwing a male screw portion formed on the outer peripheral surface of the outer cylindrical portion and a female screw portion formed in the opening, the inner cylinder A portion formed on an upper end surface of the filter element and fitted into a communication hole communicating with the inner circumferential space of the filter element so that the inner passage communicates with the inner circumferential space, and the filter element includes the inner cylindrical portion The upper end surface of the filter element and the opening of the case are separated from each other by being pushed downward with respect to the case so that the outer peripheral space and the outer passage screwed into the opening communicate with each other. A spin-on filter characterized by that. A seal member surrounding the communication hole and having a smaller inner diameter than the communication hole is disposed on the upper end surface of the filter element,
When the element assembly is attached to the filter head, the seal member abuts on the outer peripheral surface of the inner cylindrical portion to separate the inner peripheral space and the outer peripheral space. The spin-on filter according to claim 1. The inner cylindrical portion is composed of a distal end portion inserted into the communication hole of the filter element, and a proximal end portion having a larger diameter than the distal end portion,
A seal member is disposed so as to protrude upward from the upper end surface of the filter element and surround the communication hole.
When the element assembly is attached to the filter head, the seal member is in contact with the lower surface of the base end portion to separate the inner peripheral space and the outer peripheral space. The spin-on filter according to claim 1. The filter element is
A bottomed valve case in which an internal space communicates with the communication hole and protrudes into the inner peripheral space, and a valve side opening is provided on a side surface;
A valve disposed in the valve case so as to be slidable up and down, and is urged by the second elastic member to the communication hole when the element assembly is detached from the filter head, thereby closing the communication hole. Having a valve consisting of a body,
When the element assembly is attached to the filter head on the side surface of the distal end portion of the inner cylindrical portion, a head side opening that is aligned with the valve side opening is provided,
When the element assembly is attached to the filter head, the valve body is pushed downward by the inner cylindrical portion, and the valve-side opening and the head-side opening communicate with each other to connect the inner passage and the inner passage. The spin-on filter according to claim 1, wherein the spin-on filter is configured to communicate with a peripheral space.   The spin-on filter according to any one of claims 1 to 4, wherein an inflow valve and an outflow valve that are opened when a predetermined pressure is applied are provided in the outer passage and the inner passage. The case is composed of a substantially cylindrical case main body having an upper end opened and a lower end closed, and a cover member attached to the case main body so as to cover the upper end opening,
The cover member is formed with a through-hole penetrating vertically, and the female screw portion is formed in the through-hole,
When the element assembly is removed from the filter head, the upper end portion of the filter element is biased to the lower end portion of the cover member to separate the outer peripheral space and the opening portion. The spin-on filter according to any one of claims 1 to 5.

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