WO2023090375A1

WO2023090375A1 - Valve

Info

Publication number: WO2023090375A1
Application number: PCT/JP2022/042620
Authority: WO
Inventors: 弘行岩永; 健太古川; 直己西村; 優出口
Original assignee: イーグル工業株式会社
Priority date: 2021-11-17
Filing date: 2022-11-16
Publication date: 2023-05-25
Also published as: JPWO2023090375A1

Abstract

Provided is a valve capable of adjusting the biasing force of a spring without using a screw.　In a valve 1, a valve body 22 that moves in the axial direction and a spring 29 that applies a biasing force to the valve body 22 are contained in a case 2A. The valve 1 has a spring receiver 20 movable in the axial direction with respect to the case 2A. One of the case 2A and the spring receiver 20 is provided with a plurality of recessed portions 231-233 that are different in bottom position in the axial direction, and the other one of the case 2A and the spring receiver 20 is provided with a protruding portion 20c that can selectively engage with the recessed portions 231-233.

Description

valve

The present invention relates to valves, particularly valves that control working fluid.

Valves used to control working fluid in various industrial fields have a valve seat and a valve element that can be separated from and attached to the valve seat. Pressure and flow rate can be controlled.

Such valves include a spool valve in which a spool, which is a valve body, moves parallel to an opening, which is a valve seat, a butterfly valve, in which a valve body has a pivot shaft, and a valve body, which is a valve seat. A typical valve form is a lift valve that moves perpendicularly to the valve. Among these valves, in the spool valve, the direction of movement of the spool and the direction of flow of the working fluid intersect, and the fluid pressure of the working fluid is less likely to act in the direction of movement of the spool, so the responsiveness of the spool to the driving force is high. It's becoming

As a spool valve, for example, the solenoid valve of Patent Document 1 is known. The solenoid valve of Patent Document 1 includes a cylindrical sleeve, a cylindrical spool housed in the sleeve, a solenoid portion that drives the spool, a spring that urges the spool to return, and a tip of the sleeve that abuts on the spring. and a screw member fixed by screwing into. By changing the threaded position of the screw member, the biasing force applied by the spring to the spool can be adjusted, and the driving force of the solenoid portion and the biasing force of the spring can be adjusted to an appropriate balance.

JP 2021-148253 A (page 6, FIG. 1) JP 2015-28370 A (page 6, FIG. 3)

However, in the solenoid valve as disclosed in Patent Document 1, the threaded member may loosen from the sleeve over time. Therefore, as in the solenoid valve of Patent Document 2, the thin portion provided at the tip of the sleeve is crimped from the outside toward the inside to fix the screw member to the sleeve so that it cannot move relative to the sleeve in the axial direction and the circumferential direction. Although a screw member has been developed that can prevent the loosening of the screw member, since the sleeve and the screw member are screw-fixed, there is a possibility that the screw member may be axially displaced from the sleeve when the thin-walled portion is crimped. was there.

The present invention has been made with a focus on such problems, and an object of the present invention is to provide a valve that can adjust the biasing force of a spring without using screws.

In order to solve the above problems, the valve of the present invention is
A valve in which a valve body that moves in the axial direction and a spring that applies a biasing force to the valve body are accommodated in a case,
having a spring receiver axially movable with respect to the case;
One of the case and the spring receiver is provided with a plurality of recesses having different bottom positions in the axial direction, and the other of the case and the spring receiver is provided with protrusions that can be selectively engaged with the recesses. is provided.
According to this, by selecting the concave portion with which the convex portion engages, the axial position of the spring receiver in the case can be appropriately changed to adjust the biasing force of the spring. Since the engaged state is maintained, the urging force of the spring acting on the valve body can be stably exerted.

The spring receiver may be rotatable, and a plurality of the recesses having different bottom positions in the axial direction may be arranged in the circumferential direction.
According to this, the concave portion to be engaged can be easily selected by rotating the spring receiver.

The spring receiver may be accessible from outside the case.
According to this, the biasing force of the spring can be adjusted by operating the spring receiver from the outside of the case.

A through hole may be formed in the case, and an operating portion exposed to the through hole may be provided in the spring receiver.
According to this, it is possible to appropriately change the position of the spring receiver in the axial direction by operating the operating portion from the outside of the case.

The operating portion may be a groove.
According to this, the axial position of the spring receiver can be appropriately changed by engaging the jig with the groove.

The case may be provided with guide means for guiding axial movement of the spring receiver.
According to this, the concave portion and the convex portion can be engaged with each other with high accuracy.

A plurality of the convex portions may be formed extending in the radial direction.
According to this, since the protrusion and the recess extend in the radial direction, the rotation of the spring receiver is restricted, and the protrusion is less likely to separate from the recess during use.

One of said recesses may be axially through.
According to this, the case can be formed thin.

1 is a side sectional view showing a valve in Example 1 of the present invention; FIG. (a) is a side sectional view of a retainer, (b) is a view on arrow A of (a), and (c) is a view on arrow B of (a). (a) is a sectional view taken along line CC of FIG. 2, (b) is a sectional view taken along line DD, and (c) is a sectional view taken along line EE. (a) is a side sectional view of a plate, and (b) is a view in the direction of arrow F of (a). It is the schematic which shows the state by which the plate was set to the 1st position. It is the schematic which shows the state by which the plate was set to the 2nd position. It is the schematic which shows the state by which the plate was set to the 3rd position. (a) is an axial view of a retainer according to Embodiment 2 of the present invention, (b) is a cross-sectional view along GG in (a), and (c) is a cross-sectional view along HH in (a).

A form for implementing the valve according to the present invention will be described below based on an embodiment. Although the embodiment will be described with an example of a solenoid valve used in a hydraulically controlled device such as an automatic transmission of a vehicle, the present invention can also be applied to other uses.

A solenoid valve according to Embodiment 1 will be described with reference to FIGS. 1 to 7. FIG. Hereinafter, the right side of the paper surface of FIG. 1 is defined as one axial end side of the solenoid valve, and the left side of the paper surface of FIG. 1 is defined as the other axial end side of the solenoid valve.

As shown in FIG. 1, the valve of this embodiment is a spool-type solenoid valve 1, which is used in a hydraulically controlled device such as an automatic transmission of a vehicle. The solenoid valve 1 is used as a so-called oil-immersed solenoid valve that is mounted horizontally in a mounting hole of a valve housing on the device side and immersed in hydraulic oil, which is a liquid in the valve housing.

A solenoid valve 1 is constructed by integrally attaching a valve portion 2 to a solenoid portion 3 for adjusting the flow rate of a control fluid such as hydraulic oil. 1 shows an OFF state of the solenoid valve 1 in which the coil 36 of the solenoid molded body 31 is not energized.

First, the structure of the valve portion 2 will be explained. As shown in FIG. 1, the valve portion 2 mainly comprises a sleeve 21, a spool 22 as a valve body, a spring 29, a retainer 23, and a plate 20 as a spring receiver.

The sleeve 21 is provided with openings for various ports such as an input port 24, an output port 25, a discharge port 26, a drain port 27, a feedback port 28, etc., which are connected to flow paths provided in the mounting holes of the valve housing.

The spool 22 is liquid-tightly accommodated in a through hole 21a formed in the inner diameter side of the sleeve 21 in the axial direction. The spool 22 can be reciprocated in the axial direction, and by reciprocating the spool 22 in the axial direction, the communication state of various ports is changed to control the pressure and flow rate of hydraulic oil. .

The spring 29 biases the spool 22 toward the other axial end. The retainer 23 is attached to one axial end of the sleeve 21 . The plate 20 is arranged inside the bottom wall portion 23 b (see FIG. 2 ) of the retainer 23 and abuts one end of the spring 29 .

The case 2A in the present invention consists of a sleeve 21 and a retainer 23, and accommodates a spool 22, a spring 29 and a plate 20.

The sleeve 21, spool 22, retainer 23, and plate 20 are made of materials such as aluminum, iron, stainless steel, and resin. The structures of the retainer 23 and the plate 20 will be detailed later.

Next, the structure of the solenoid portion 3 will be described. As shown in FIG. 1, the solenoid portion 3 is mainly composed of a solenoid case 30, a stator 32, a side ring 33, a tubular body 7, a bush 9, an end plate 34, and a plunger 35. It is

The solenoid case 30 is a cylindrical body made of a magnetic metal material such as iron, and has one end connected to the other end of the sleeve 21 . The solenoid molded body 31 is formed by molding the coil 36 with resin. The stator 32 is made of a magnetic metal material such as iron, and is arranged inside the solenoid molded body 31 at one end in the axial direction. The side ring 33 is made of a magnetic metal material such as iron, and is arranged inside the solenoid molded body 31 on the other axial end side.

The cylindrical body 7 is made of a non-magnetic material and arranged between the stator 32 and the side ring 33 spaced apart in the axial direction. The bushing 9 is made of a non-magnetic material, and is arranged axially inside the tubular body 7 and the side ring 33 . The end plate 34 is made of a magnetic metal material such as iron, and functions as a lid member that closes the opening at the other axial end of the solenoid case 30 .

The plunger 35 is formed in a columnar shape from a magnetic metal material such as iron, and moves axially in a space surrounded by the stator 32, the cylindrical body 7, the side ring 33, the bush 9, and the end plate 34. It is a movable iron core arranged in a possible state. The plunger 35 is slidable inside the bush 9 .

When the solenoid valve 1 is in the OFF state, the spool 22 is urged toward the other end in the axial direction by the urging force of the spring 29. Accordingly, the rod 5 slidably inserted through the hole 32c of the plunger 35 and the stator 32 is displaced. It has moved to the other end in the axial direction.

Further, although not shown, when the solenoid valve 1 is in the ON state, a magnetic circuit is formed by the solenoid case 30, the end plate 34, the side ring 33, the plunger 35, and the stator 32 by energizing the coil 36 of the solenoid molded body 31. A magnetic force is generated between the plunger 32 and the plunger 35 to axially move the plunger 35 and the rod 5 toward the stator 32 side.

By moving the spool 22 in the axial direction in this manner, the amount of control fluid flowing from the input port 24 to the output port 25 of the sleeve 21 can be varied.

Next, the structure of the retainer 23 will be explained. As shown in FIG. 2, the retainer 23 includes a cylindrical side wall portion 23a and a bottom wall portion 23b that closes an opening at one end of the side wall portion 23a. It has a tubular shape. The other end of the side wall portion 23a is formed with a flange portion 23c that is bent radially outward. A sleeve 21 is connected (see FIG. 1).

A circular through hole 23d is formed in the center of the bottom wall portion 23b so as to extend therethrough in the axial direction. 231, a plurality of first grooves 232 as recesses, and a plurality of second grooves 233 as recesses (three each in this embodiment) are equally arranged. In FIG. 2(c), the first grooves 232 are shown with dark dots, and the second grooves 233 are shown with light dots for easy understanding.

As shown in FIGS. 2(b), 2(c) and 3(a), the through groove 231 penetrates in the axial direction. In other words, the axial dimension L1 of the through groove 231 is the same dimension as the thickness of the bottom wall portion 23b. The axial dimension L1 of the through groove 231 is larger than the axial dimension L10 (see FIG. 4) of the projection 20c of the plate 20 (L1>L10).

2(c) and 3(b), the first groove 232 has a bottom surface 232a whose axial dimension L2 is equal to the axial dimension L1 of the through groove 231. (L1>L2). The axial dimension L2 of the first groove 232 is smaller than the axial dimension L10 of the projection 20c of the plate 20 (L2<L10).

2(c) and 3(c), the second groove 233 has a bottom surface 233a whose axial dimension L3 is It is smaller than the dimension L2 (L2>L3).

Next, the structure of the plate 20 will be explained. As shown in FIG. 4, the plate 20 is
It has a disk-shaped base portion 20a, a projecting portion 20b projecting in a columnar shape from the center portion of the base portion 20a, and a plurality of (three in the embodiment) projecting portions 20c radially extending from the projecting portion 20b. .

The base portion 20a is provided with a slightly smaller diameter than the inner diameter of the side wall portion 23a. Moreover, the projecting portion 20b is provided with a slightly smaller diameter than the through hole 23d. Further, an operation groove 20d is formed as an operation portion penetrating in the axial direction in the projecting portion 20b. The operation groove 20d has a rectangular shape when viewed in the axial direction.

The convex portions 20c are evenly distributed around the protruding portion 20b, and one convex portion 20c is orthogonal to the extending direction of the operation groove 20d. The convex portion 20c has an axial dimension L10.

Next, the first, second and third axial positions of the plate 20 will be described. A procedure for changing the position in the axial direction will be described later.

5 shows the first position of the plate 20. FIG. At this time, the protrusions 20b of the plate 20 are inserted into the through holes 23d of the retainer 23, the protrusions 20c of the plate 20 are engaged with the through grooves 231 of the retainer 23, and the base 20a of the plate 20 is inserted into the retainer 23. is in contact with the bottom wall portion 23b.

At the first position of the plate 20, the supporting surface 20e of the spring 29 on the plate 20 and the supporting surface 22a of the spring 29 on the spool 22 are separated in the axial direction by a distance D1.

The relative rotation between the plate 20 and the retainer 23 is restricted by engaging the protrusions 20c with the through grooves 231. Further, each convex portion 20c of the plate 20 is kept engaged with each through groove 231 of the retainer 23 by pressing the base portion 20a against the bottom wall portion 23b by the biasing force of the spring 29. As shown in FIG.

6 shows the second position of the plate 20. FIG. At this time, the protrusions 20b of the plate 20 are inserted into the through holes 23d of the retainer 23, the protrusions 20c of the plate 20 are engaged with the first grooves 232 of the retainer 23, and the base 20a of the plate 20 is inserted into the retainer 23. is slightly spaced from the bottom wall portion 23b of the other side.

At the second position of the plate 20, the supporting surface 20e of the spring 29 on the plate 20 and the supporting surface 22a of the spring 29 on the spool 22 are axially separated by a distance D2 shorter than the distance D1 (D1 >D2).

Each projection 20c of the plate 20 is pressed against the bottom surface 232a of each first groove 232 of the retainer 23 by the biasing force of the spring 29 so that the state of engagement with each first groove 232 is maintained. It's becoming

7 shows the third position of the plate 20. FIG. At this time, the protrusions 20b of the plate 20 are inserted into the through holes 23d of the retainer 23, the protrusions 20c of the plate 20 are engaged with the second grooves 233 of the retainer 23, and the base 20a of the plate 20 is as shown in FIG. It is further separated from the bottom wall portion 23b of the retainer 23 to the other side than in the state of .

At the third position of the plate 20, the supporting surface 20e of the spring 29 on the plate 20 and the supporting surface 22a of the spring 29 on the spool 22 are axially separated by a distance D3 shorter than the distance D2 (D2 >D3).

Each projection 20c of the plate 20 is pressed against the bottom surface 233a of each second groove 233 of the retainer 23 by the biasing force of the spring 29 so that the state of engagement with each second groove 233 is maintained. It's becoming

As described above, the separation distance between the support surface 20e of the spring 29 and the support surface 22a of the spring 29 on the spool 22 is D1>D2>D3. The urging force of the spring 29 is small, the urging force of the spring 29 is larger at the second position of the plate 20 than at the first position, and the largest at the third position of the plate 20. can be set to

Next, a procedure for changing the axial position of the plate 20 will be described. A jig (not shown) is engaged with the operating groove 20d through the through hole 23d of the retainer 23 from the outside, and is moved in the axial direction and then rotated around the axis, thereby moving each convex portion 20c into the through groove 231 and the first concave portion. Either the groove 232 or the second concave groove 233 is selectively engaged. In this manner, the axial position of the plate 20 can be changed.

For example, when changing the plate 20 from the first position to the second position, the plate 20 is moved to the other side in the axial direction against the biasing force of the spring 29 from the outside, and is rotated around the axis (clockwise in this embodiment). 40 degrees), and then the plate 20 is returned to one side in the axial direction by the biasing force of the spring 29, so that the positions where the protrusions 20c of the plate 20 are engaged are shifted from the through grooves 231 of the retainer 23. Each first concave groove 232 is changed.

In addition, the outer peripheral surface of the projecting portion 20b of the plate 20 always slides along the inner peripheral surface of the through hole 23d when the plate 20 moves from the first position to the third position. The outer peripheral surface of the base portion 20a of the plate 20 always slides along the inner peripheral surface of the side wall portion 23a of the retainer 23 when the plate 20 moves from the first position to the third position. That is, the inner peripheral surface of the through hole 23d and the inner peripheral surface of the side wall portion 23a of the retainer 23 function as guide means G for guiding the movement of the plate 20 in the axial direction.

As described above, by selecting the through groove 231, the first groove 232, and the second groove 233 with which the projection 20c engages, the axial position of the plate 20 in the sleeve 21 can be appropriately changed, and the spring 29 can be adjusted. In addition, the convex portion 20c is kept engaged with any one of the through groove 231, the first concave groove 232, and the second concave groove 233 by the biasing force of the spring 29. The urging force of the acting spring 29 can be stably exerted.

Further, the plate 20 is rotatable around the axis, and the plurality of through grooves 231, the first grooves 232, and the second grooves 233 are arranged in the circumferential direction of the base 20a of the plate 20, so that the plate 20 can be rotated around the axis. 231, the first recessed groove 232, and the second recessed groove 233 to be engaged with the convex portion 20c can be easily selected.

Also, the plate 20 can be accessed from the outside of the sleeve 21 and the retainer 23, and the biasing force of the spring 29 can be adjusted by operating the plate 20 from the outside.

Specifically, the retainer 23 is formed with a through hole 23d, and the plate 20 is provided with an operation groove 20d exposed to the through hole 23d. The position of the direction can be changed as appropriate. Further, since a jig can be engaged with the operation groove 20d, the work of changing the position of the plate 20 in the axial direction from the outside can be easily performed.

Furthermore, the operation groove 20d penetrates in the axial direction. According to this, the operation groove 20d can be used as a breathing hole that communicates the space defined by the spool 22, the sleeve 21, the retainer 23, and the plate 20 and housing the spring 29 with the external space. It is possible to avoid pressure build-up in the space where

Further, since one convex portion 20c of the plate 20 is perpendicular to the extending direction of the operation groove 20d, the position of the one convex portion 20c can be grasped from the outside with reference to the operation groove 20d. , the work of engaging the convex portion 20c with any one of the through groove 231, the first concave groove 232, and the second concave groove 233 is simple.

The retainer 23 has an inner peripheral surface of a through hole 23d on which the outer peripheral surface of the projecting portion 20b of the plate 20 slides, and an inner peripheral surface of the side wall portion 23a on which the outer peripheral surface of the base portion 20a of the plate 20 slides. is provided. According to this, the movement of the plate 20 in the axial direction is guided by the inner peripheral surface of the through hole 23d and the inner peripheral surface of the side wall portion 23a. 2 concave groove 233 can be engaged precisely.

In this embodiment, the configuration in which two guide means G are provided was exemplified, but as long as at least one is provided, the other structure may be omitted. When used as guide means, the outer diameter of the base portion 20a of the plate 20 may be smaller than the inner circumference of the side wall portion 23a of the retainer 23 .

Further, since a plurality of projections 20c are formed extending in the radial direction, the rotation of the plate 20 with respect to the retainer 23 is regulated. The protrusion 20 c is difficult to separate from the first groove 232 and the second groove 233 .

In addition, since the convex portions 20c are evenly distributed in the circumferential direction, the engaging portions can be arranged in a well-balanced manner in the circumferential direction of the plate 20, and the plate 20 can be prevented from tilting.

In addition, since one of the concave portions is the through groove 231 penetrating in the axial direction, the thickness of the bottom wall portion 23b of the retainer 23 can be made thin. Also, the position of the projection 20c of the plate 20 can be confirmed from the outside through the through groove 231. FIG.

Also, since the plate 20 is thin in the axial direction, the axial dimension of the solenoid valve 1 can be reduced. The shape of the spring receiver is not limited to a plate shape, and may be freely changed to, for example, a cylindrical shape elongated in the axial direction.

Further, since the axial dimension of the protruding portion 20b is larger than the axial dimension L10 of the protruding portion 20c, when changing the axial position of the plate 20, by inserting the protruding portion 20b into the through hole 23d, It is possible to align the protrusion 20c in the radial direction.

In addition, at the first position (see FIG. 5) of the plate 20, the end surface of the projecting portion 20b and the end surface of the bottom wall portion 23b are flush with each other outward (one end in the axial direction). According to this, the end surface of the projecting portion 20b and the end surface of the bottom wall portion 23b are flush with each other, so that it is possible to recognize from the outside that the plate 20 is arranged at the first position.

Next, the valve according to Example 2 will be described with reference to FIG. It should be noted that the description of the configuration that is the same as that of the above-described embodiment and overlaps will be omitted.

As shown in FIG. 8, the bottom wall portion 300a of the retainer 300 of the second embodiment has a first concave groove 301 as a concave portion, a second concave groove 302 as a concave portion, and a third concave groove as a concave portion. 303 and a through hole 304 are formed. The first groove 301, the second groove 302, and the third groove 303 are formed to extend radially outward from a through hole 304 provided in the center of the bottom wall portion 300a.

The bottom surface 301a of the first groove 301 is positioned closer to one end than the bottom surface 302a of the second groove 302. Also, the bottom surface 302a of the second groove 302 is located closer to one end than the bottom surface 303a of the third groove 303. As shown in FIG.

That is, the axial dimension L1′ of the first groove 301 is greater than the axial dimension L2′ of the second groove 302, and the axial dimension L2′ of the second groove 302 is greater than that of the third groove 303. greater than the axial dimension L3' (L1'>L2'>L3'). In this way, the recess may be composed only of a recess that does not penetrate in the axial direction.

The end surface of each projection 20c of the plate 20 (see FIG. 4) is aligned with the bottom surface 301a of each first groove 301 at the first position of the plate 20, and the bottom surface 302a of each second groove 302 at the second position of the plate 20. , contact the bottom surface 303a of each third groove 303 at the third position of the plate 20, respectively. That is, at any position on the plate 20, the end face of each projection 20c of the plate 20 similarly abuts on one of the bottom faces, so that the state in which the plate 20 is arranged is stable.

Although the embodiments of the present invention have been described above with reference to the drawings, the specific configuration is not limited to these embodiments, and any changes or additions within the scope of the present invention are included in the present invention. be

For example, in the above embodiment, the convex portion is provided on the spring receiving side and the concave portion is provided on the case side, but the concave portion may be provided on the spring receiving side and the convex portion on the case side.

Further, in the above-described embodiment, the concave portion and the convex portion are provided between the bottom wall portion of the case and the opposing surface of the spring receiver that faces the bottom wall portion. A concave portion and a convex portion may be provided between the side portion of the spring receiver.

Also, in the above-described embodiment, the case is composed of a sleeve and a retainer, but the case may be composed of a single member.

Further, in the above embodiment, the spring receiver is rotated around the axis to selectively change the concave portion with which the convex portion engages. may be adapted to selectively change the concave portion with which the convex portion engages by moving the in the radial direction.

Also, in the above embodiment, the recesses and protrusions extend radially, but the recesses and protrusions do not have to extend radially. For example, they may have a square shape when viewed in the axial direction, and may be scattered in the circumferential direction of the spring receiver and the case.

Also, in the above-described embodiment, the form in which a plurality of protrusions are evenly distributed in the circumferential direction with respect to the spring receiver was exemplified, but at least one protrusion may be provided.

Also, in the above embodiments, the spool type solenoid valve using a spool as the valve body has been described, but the present invention is not limited to this, and may be a solenoid valve using a globe valve, a gate valve, or the like.

1 Solenoid valve (valve)
2A case 20 plate (spring receiver)
20c convex portion 20d operating groove (operating portion)
21 sleeve (case)
22 spool (valve)
23 retainer (case)
23a side wall (guide means)
23d through hole (guide means)
29 spring 35 plunger 231 through groove (recess)
232 first groove (recess)
233 Second groove (recess)
300 retainer (case)
301 first groove (recess)
302 second groove (recess)
303 Third groove (recess)
G guide means

Claims

A valve in which a valve body that moves in the axial direction and a spring that applies a biasing force to the valve body are accommodated in a case,
having a spring receiver axially movable with respect to the case;
One of the case and the spring receiver is provided with a plurality of recesses having different bottom positions in the axial direction, and the other of the case and the spring receiver is provided with protrusions that can be selectively engaged with the recesses. A valve, characterized in that it is provided with:
The valve according to claim 1, wherein the spring receiver is rotatable, and a plurality of the recesses having different bottom positions in the axial direction are arranged in the circumferential direction.
The valve according to claim 1 or 2, wherein the spring receiver is accessible from the outside of the case.
The valve according to claim 3, wherein a through hole is formed in the case, and an operating portion exposed to the through hole is provided in the spring receiver.
The valve according to claim 4, wherein the operating portion is a groove.
The valve according to claim 1, wherein the case is provided with guide means for guiding axial movement of the spring receiver.
The valve according to claim 1, wherein a plurality of said protrusions are formed extending in a radial direction.
The valve according to claim 1, wherein one of said recesses is axially through.