JP2011137495A - Sliding mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a sliding mechanism preventing seizure over a long time. <P>SOLUTION: The sliding mechanism includes a valve element 10, a valve body 3 having a valve element supporting hole 5 slidably supporting the valve element 10, and a multilayered film 20 formed in the multilayer on an outer surface of the valve element 10 of an inner surface of the valve element supporting hole 5 and the outer surface of the valve element 10 and having the hard layer harder than the others as the outermost surface layer 20a. A thickness t of the multilayered film 20 is larger than a maximum outside diameter L2 of maximum foreign matter 30a of foreign matter 30 capable of entering a gap 21 between the multilayered film 20 and the other. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a sliding device in which water is interposed in a sliding portion, for example, a hydraulic device used in a fluid injection device that injects a fluid (for example, water) that lowers a combustion temperature into a cylinder of an internal combustion engine.

  The above-described conventional fluid ejecting apparatus incorporates a sliding mechanism in which the valve body slides with respect to a valve body support hole into which the needle-like valve body is slidably inserted in the axial direction. Generally, seizure of the sliding portion is prevented by supplying lubricating oil to the sliding portion of the moving mechanism.

  As the above-described sliding mechanism, a configuration has been proposed in which a hard layer, for example, a layer made of Stellite (registered trademark) is formed on the surface of the sliding portion by overlaying (for example, see Patent Document 1). When the above-mentioned stellite material was used, although it was effective in suppressing burn-in, it was not a sufficient level. Furthermore, the sliding mechanism requires a means for supplying the lubricating oil, and there is a problem that the cost becomes high.

Japanese Patent Laid-Open No. 2007-117887

  In order to find a sliding mechanism capable of preventing seizure over a long period of time, the applicant of the present application replaces the stellite material with a hard layer that is harder than the stellite material. An experiment was carried out using what was formed on the sliding portion between the inner surface of the valve and the outer surface of the valve body.

  FIG. 7 shows an example of the experimental results. A diamond-like carbon (DLC) film is used as the hard layer, a valve body having a valve body support hole and SUS630 is used for the valve body, and the valve body is about 350,000. This is a case where the endurance test was performed by sliding it once.

  As understood from FIG. 7, the DLC film 100 has a linear scratch (a blackened portion) 101 peeled along the sliding direction B, and the sliding direction B connected to the linear scratch 101. A scratch (blackened portion) 102 peeled off with a width in the orthogonal direction was generated, and it was found that there was a problem in durability.

  The present invention has been made to solve the above-described problems of the prior art, and an object thereof is to provide a sliding mechanism capable of preventing seizure over a long period of time.

  A sliding mechanism according to claim 1 of the present invention includes a valve body, a support member having a valve body support hole that slidably supports the valve body, an inner surface of the valve body support hole, and an outer surface of the valve body. A multi-layer coating having a hard layer harder than the other as the outermost surface layer, and the thickness of the multi-layer coating is a foreign substance that can enter a gap between the multi-layer coating and the other. It is characterized by being larger than the outer diameter of the foreign material having the largest outer diameter.

  A sliding mechanism according to a second aspect of the present invention is the sliding mechanism according to the first aspect, wherein the one on which the multilayer coating is formed is harder than the other.

  The sliding mechanism according to claim 3 of the present invention is the sliding mechanism according to claim 2, wherein the thickness of the multilayer coating is the largest outside of the foreign matter that can enter the gap between the multilayer coating and the other. It is characterized by being larger than 0.5 times the outer diameter of the foreign substance having a diameter.

  A sliding mechanism according to claim 4 of the present invention includes a valve body, a support member having a valve body support hole that slidably supports the valve body, an inner surface of the valve body support hole, and an outer surface of the valve body. A multilayer coating having a hard layer harder than the other as the outermost surface layer, and the thickness of the multilayer coating is larger than the designed gap dimension between the multilayer coating and the other It is characterized by that.

  A sliding mechanism according to a fifth aspect of the present invention is the sliding mechanism according to the fourth aspect, characterized in that the one on which the multilayer coating is formed is harder than the other.

  A sliding mechanism according to a sixth aspect of the present invention is the sliding mechanism according to the fifth aspect, wherein the thickness of the multilayer coating is more than 0.5 times the designed clearance dimension between the multilayer coating and the other. Is also large.

  In the case of the sliding mechanism according to the present invention, the foreign matter having an outer diameter larger than the size of the gap between the multilayer coating formed on one of the inner surface of the valve body support hole and the outer surface of the valve body and the other enters the gap. I don't get it. On the other hand, even if a foreign matter having the same outer diameter as the gap enters the gap, the thickness of the multilayer coating is larger than the maximum outer diameter of the foreign matter, so the base of the multilayer coating (the inner surface of the valve body support hole or The outer surface of the valve body is not exposed. As a result, the sliding state between the inner surface of the valve body support hole and the outer surface of the valve body can be maintained for a long time, and seizure can be prevented for a long time.

  In the case of the invention according to claim 2, since the foreign matter entering between the multilayer coating and the other penetrates deeply into the other side of the soft, the other side is recessed larger than the one side, and the multilayer coating formed on one side Can reduce the degree of damage.

  In the case of the invention of claim 3, since the foreign matter that has entered between the multilayer coating and the other penetrates deeply into the other side of the soft, the other side is recessed larger than the one side, and the multilayer coating formed on one side Is reduced, and the recess on one side is less than half of the maximum outer diameter of the foreign matter. Therefore, even if the thickness of the multilayer coating is 0.5 times the outer diameter of the foreign matter having the largest outer diameter among the foreign matters that can enter the gap between the multilayer coating and the other, the base can be exposed. Absent. Therefore, since the thickness of the multilayer coating may be larger than 0.5 times the maximum outer diameter, the production cost of the multilayer coating can be reduced.

  In the case of the invention according to claim 4, the foreign matter having an outer diameter larger than the designed gap dimension in the gap between the multilayer coating formed on one of the inner surface of the valve body support hole and the outer surface of the valve body and the other is put in the gap. I can't get in. On the other hand, even if a foreign matter having an outer diameter substantially the same as the designed gap dimension enters the gap, the thickness of the multilayer coating is larger than the designed gap size (outer diameter of the foreign matter). The inner surface of the valve body support hole or the outer surface of the valve body is not exposed. As a result, the sliding state between the inner surface of the valve body support hole and the outer surface of the valve body can be maintained for a long time, and seizure can be prevented for a long time. Here, the above-described design clearance dimension is the fluidity from the clearance between the valve body and the valve body support hole in the state where the axis of the valve body support hole and the axis of the valve body coincide. It is determined in consideration of the presence or absence of leakage and processing accuracy.

  In the case of the invention according to claim 5, since the foreign matter entering between the multilayer coating and the other penetrates deeply into the other side of the soft, the other side is recessed larger than the one side, and the multilayer coating formed on one side Can reduce the degree of damage.

  In the case of the invention according to claim 6, since the foreign matter that has entered between the multilayer coating and the other penetrates deeply into the other side of the soft, the other side is recessed larger than the one side, and the multilayer coating formed on one side Therefore, even if the thickness of the multilayer coating is larger than 0.5 times the designed gap dimension between the multilayer coating and the other, the ground is not exposed. Therefore, since the gap dimension can be doubled, it is not necessary to increase the processing accuracy for gap management, and the manufacturing cost can be reduced.

It is a schematic diagram which shows the hydraulic equipment apparatus incorporating the sliding mechanism which concerns on 1st Embodiment of this invention. It is a figure which shows the state which the foreign material entered into the sliding part of the inner surface of a valve body support hole and the outer surface of a valve body in the sliding mechanism which concerns on 1st Embodiment. It is a figure which shows the state by which the sliding part of the inner surface of a valve body support hole and the outer surface of a valve body was damaged by the foreign material in the sliding mechanism which concerns on 1st Embodiment. It is a figure which shows a mode that the multilayer film was damaged by the foreign material in the sliding mechanism which concerns on 1st Embodiment. It is a figure which shows the state which the foreign material entered into the sliding part of the inner surface of a valve body support hole, and the outer surface of a valve body in the sliding mechanism which concerns on 2nd Embodiment. It is explanatory drawing of an oval spherical foreign material. It is a figure which shows a mode that the DLC film of the prior art example was damaged by the foreign material.

  Embodiments of the present invention will be specifically described below.

(First embodiment)
FIG. 1 is a schematic view showing a hydraulic device apparatus incorporating a sliding mechanism according to the first embodiment of the present invention.

  The hydraulic device 1 includes a valve body 3 having a valve body support hole 5 and a fluid passage 7 therein, and a valve body 10 provided in the valve body support hole 5, and the valve body support hole in the valve body 3. 5 and the valve body 10 constitute a sliding mechanism 8.

  The valve body 3 is generally formed in a cylindrical shape with a bottom, and is long in the axial direction A. The bottom 3a of the valve body 3 has one side in the axial direction A (the lower side in FIG. 1). ) Is provided with an outlet 7a for sending a fluid, for example water, to another device. Here, one side (lower side) of the hydraulic device 1 shown in FIG. 1 is referred to as a distal end side, and the other side (upper side) opposite to the one side is referred to as a proximal end side.

  The valve body support hole 5 is an internal cavity having a circular cross section perpendicular to the axial direction A, and the valve body support hole 5 is provided with a valve body 10 slidable in the axial direction A. About half of the base end side of the valve element 10 is supported inside the valve element support hole 5, while the remaining part on the distal end side protrudes outward from the valve element support hole 5. The valve body 10 has an opening / closing valve portion 11 on the distal end side, and slides with a position where the opening / closing valve portion 11 contacts an annular valve seat 3b provided in the valve body 3 as a valve closing position.

  The fluid passage 7 includes the outlet 7a, a first passage 7b connected to the outlet 7a, a second passage 7c connected to the first passage 7b, and a fluid supply port 7d connected to the second passage 7c.

  The first passage 7b is an inner cavity that is closer to the distal end than the valve seat 3b and has a circular cross section. The inner diameter of the first passage 7b is smaller than the inner diameter of the valve body support hole 5, and the proximal end of the first passage 7b. The annular valve seat 3b is formed on the inner wall portion of the valve body 3 corresponding to the above.

  The second passage 7c is an internal cavity that is located between the first passage 7b and the valve body support hole 5 and has a circular cross section perpendicular to the axial direction A. The inner diameter of the second passage 7c is The inner diameter of the one passage 7b and the inner diameter of the valve body support hole 5 are larger. Therefore, there is a gap between the outer periphery of the valve body 10 (multilayer coating 20 described later) and the inner wall (the inner surface facing the axis) of the second passage 7c facing the outer periphery, and is not in contact with each other. ing.

  A plurality of, for example, two fluid supply ports 7d are provided through the outer peripheral wall of the valve body 3, and each fluid supply port 7d communicates with the second passage 7c. A fluid is supplied from the outside to each fluid supply port 7d. The number of fluid supply ports 7d is not limited to a plurality and may be a single number.

  In the fluid passage 7 configured as described above, fluid is supplied from the outside to the fluid supply port 7d, and the supplied fluid is sent to the outlet 7a via the second passage 7c and the first passage 7b. When the valve body 10 slides toward the valve closing position and the on-off valve portion 11 contacts the valve seat 3b, the contact between the first passage 7b and the second passage 7c is blocked. Closed. On the other hand, when the valve body 10 moves to the base end side from the valve closing position, that is, when the on-off valve portion 11 is separated from the valve seat 3b, the first passage 7b and the second passage 7c communicate with each other to be in an open state. Become. In the open state, the fluid supplied from the outside to the fluid supply port 7d is supplied from the outlet 7a to other devices via the second passage 7c and the first passage 7b. On the other hand, in the closed state, the supply of fluid from the outlet 7a is stopped.

  A retaining member 6 for preventing the valve body 10 from falling off is attached to the base end side of the valve body support hole 5. The retaining member 6 is formed with a through hole 6a in a penetrating state, and this through hole 6a allows the fluid in and out of the valve body support hole 5 to be allowed to slide the valve body 10 without any trouble. belongs to.

  The valve body 10 has a circular cross section perpendicular to the axial direction A, and is formed with a solid distal end portion 12 and a hollow proximal end portion 13. The on-off valve portion 11 is provided. The on-off valve portion 11 is formed in a truncated cone shape having a smaller diameter toward the tip side.

  When the solenoid valve (not shown) is energized, the valve element 10 slides in the axial direction A so that the on-off valve portion 11 is separated from the valve seat 3b by the action of the electromagnetic force, so that the fluid passage 7 is opened. Become. On the other hand, when the electromagnetic valve is disconnected, a pressure urging force is received by the spring 15 provided inside the hollow base end portion 13 so as to contact the valve seat 3b, thereby closing the fluid passage 7. The valve is closed. The hollow base end portion 13 may be omitted as long as the spring 15 can be restrained in a predetermined posture.

  The outer periphery of the base end portion of the valve body 10 relative to the opening / closing valve portion 11 is a portion that slides relative to the inner peripheral surface of the valve body support hole 5, and the outer surface of the sliding portion of the valve body 10 A multilayer coating 20 is formed. The multilayer coating 20 suppresses wear and breakage of the valve body 10, and has a plurality of coatings as shown in FIG. 2, and the outermost surface layer 20 a on the side in contact with the inner surface of the valve body support hole 5. Is a hard layer harder than the hardness of the valve body 3. For example, the material of the valve body 3 is made of SUS630, and the material of the outermost surface layer 20a is made of DLC that is harder than that. As the outermost surface layer 20a, a chrome plating layer or a ceramic coating layer can be used.

  The multilayer coating 20 slides with respect to the valve body support hole 5 when the valve body 10 slides in the axial direction A. The multilayer coating 20 includes at least one metal film selected from the group consisting of W, Ta, Mo, Nb, Cr, and Al, for example, as a film below the outermost surface layer 20a.

  The material of the valve body 10 on which the multilayer coating 20 is formed is made of, for example, Silicoloy XVI (registered trademark), and the valve body 10 is harder than the valve body 3.

  As shown in FIG. 2, a gap 21 is formed between the multilayer coating 20 formed on the valve body 10 and the inner surface of the valve body support hole 5. The gap 21 is set to a designed gap dimension. The clearance dimension in the design is based on the slidability of the valve body 10 and the clearance between the valve body 10 and the valve body support hole 5 in a state where the axis of the valve body support hole 5 and the axis of the valve body 10 coincide. It is determined in consideration of the presence or absence of fluid leakage and processing accuracy.

  The size of the gap 21 may change depending on the circumferential position of the valve body 10 when the axis of the valve body 10 is eccentric with respect to the axis of the valve body support hole 5. The maximum value of the gap 21 at this time is L1.

  Moreover, the foreign substance 30 contained in the fluid (water) can enter the gap 21. The foreign matter 30 is mainly generated from fluid (water) and oxides in the piping. As the fluid (water), for example, water cleanliness of grades 5 to 12 (NAS 1638 contamination standard) Things are used.

  Here, as the foreign material 30, for example, a spherical material will be described as an example.

  A value obtained when the valve body 10 is eccentric with respect to the valve body support hole 5 and the gap 21 between the valve body 3 and the valve body 10 is maximized is defined as a maximum value L1. Of the foreign matters that can enter the gap 21 having the maximum value L1, the outer diameter of the largest foreign matter 30a is L2, and this foreign matter 30a is assumed to have entered the gap 21. The thickness t of the multilayer coating 20 is formed to be larger than the maximum outer diameter L2 (see FIG. 2) of the foreign material 30a.

  Next, the content of the seizure prevention in the sliding mechanism 8 of the hydraulic device 1 according to the first embodiment configured as described above will be described.

  The spherical foreign substance 30 described above cannot enter the gap 21 when its outer diameter is larger than the maximum value L1 of the gap 21. On the other hand, the foreign matter 30a having the maximum outer diameter L2 that is substantially the same as the maximum value L1 of the gap 21 or the foreign matter 30 having an outer diameter smaller than the maximum outer diameter L2 can enter the gap 21 having the maximum value L1. In this case, since the thickness t of the multilayer coating 20 is larger than the maximum outer diameter L2 of the foreign matter 30a, the peeled portion of the multilayer coating 20 due to the foreign matter 30a does not reach the valve body 10 that is the base of the multilayer coating 20, The valve body 10 is not exposed. Thereby, the sliding state between the multilayer coating 20 and the inner surface of the valve body support hole 5 can be maintained over a long period of time, and seizure can be prevented over a long period of time.

  Further, in the first embodiment, the multilayer coating 20 is formed on the valve body 10 side, and the valve body 10 on which the multilayer coating 20 is formed is made of a material (valve of the inner surface portion of the valve body support hole 5. Since the material 30 is harder than the material 3 of the main body 3, the foreign matter 30 that has entered between the multilayer coating 20 and the valve body support hole 5 is deeper into the inner surface side of the soft valve body support hole 5 as shown in FIG. Get in. That is, the depth D2 at which the foreign matter 30 enters the inner surface of the valve body support hole 5 is greater than the depth D1 at which the foreign matter 30 enters the multilayer coating 20. For this reason, the inner surface side of the valve body support hole 5 is recessed larger than the multilayer coating 20 side, and the degree to which the multilayer coating 20 is damaged can be reduced.

  That is, when the base of the valve body 10 and the valve body 3 is formed of the same material, the valve body is approximately evenly divided when the valve body 10 and the valve body 3 are pressed without considering the multilayer coating. 10 and the valve body 3 enter the ground. On the other hand, since the base of the valve body 10 is formed of a material harder than the material of the valve body 3, the depth at which the foreign matter 30a enters the valve body 10 is deeper than half of the maximum value L1 of the gap 21. It reduces that.

  For this reason, even if the thickness t of the multilayer coating 20 is 0.5 times the maximum outer diameter L2 of the foreign matter 30a, the possibility of exposing the base is reduced, and the production cost of the multilayer coating 20 can be reduced. That is, if the multilayer coating 20 is thickened, cracks may occur due to the distortion of the multilayer coating 20 itself, and thickening the multilayer coating 20 requires advanced production technology and cost, but the thickness t of the multilayer coating 20 is halved. By obtaining, the production cost of the multilayer coating 20 can be reduced as described above. Further, from the opposite viewpoint, if the thickness t of the multilayer coating 20 is left as it is, it is possible to deal with the foreign matter 30a whose maximum outer diameter is twice, that is, the gap 21 can be doubled. Thereby, the processing precision for the dimension management of the clearance gap 21 can be lowered | hung, and the manufacturing cost of the valve body 10 and the valve main body 3 can be reduced.

  FIG. 4 is a diagram illustrating a state in which the valve body 10 is slid 1 million times in the first embodiment, and the multilayer coating 20 is damaged by the foreign material 30.

  As understood from FIG. 4, in the case of the first embodiment, the multilayer coating 20 is difficult to peel off, and the scratches (blackened portions) 22 formed by peeling off the multilayer coating 20 are reduced. Therefore, the sliding state between the multilayer coating 20 and the inner surface of the valve body support hole 5 can be maintained for a long time, and seizure can be prevented for a long time.

(Second Embodiment)
In the first embodiment described above, the thickness t of the multilayer coating 20 is based on the maximum outer diameter L2 of the foreign matter 30a having the maximum outer diameter L2 among the foreign matters that can enter the gap 21 having the maximum value L1, and from the reference However, in the second embodiment, as shown in FIG. 5, the gap 21 is set to a designed gap dimension L4 and the thickness t of the multilayer coating 20 is designed. It is formed larger than the upper gap dimension L4. As described above, the designed clearance dimension L4 is such that the slidability of the valve body 10 and the valve body 10 and the valve body support hole 5 are in a state where the axis of the valve body support hole 5 and the axis of the valve body 10 coincide. It is determined in consideration of the presence or absence of fluid leakage from the gap and machining accuracy. The other parts are configured in the same manner as in the first embodiment.

  In the second embodiment, a spherical foreign material 30 having an outer diameter larger than the designed gap dimension L4 cannot enter the gap 21. On the other hand, the foreign matter 30 having an outer diameter substantially the same as the designed gap dimension L4 or smaller than the designed gap dimension L4 can enter the gap 21, but the thickness t of the multilayer coating 20 is the designed gap dimension. Since it is larger than L4 (the outer diameter of the foreign matter 30), the peeled portion of the multilayer coating 20 due to the foreign matter 30 does not reach the valve body 10 which is the base of the multilayer coating 20, and the outer surface of the valve body 10 is not exposed. Thereby, the sliding state between the multilayer coating 20 and the inner surface of the valve body support hole 5 can be maintained over a long period of time, and seizure can be prevented over a long period of time.

  In addition, although the 1st, 2nd embodiment mentioned above has demonstrated the relationship between the spherical foreign material 30, the multilayer membrane | film | coat 20, and the clearance gap 21, this invention is not restricted to this, and an elliptic spherical (egg-shaped) foreign material and The relationship between the multilayer coating and the gap can also be dealt with by thinking as follows.

  FIG. 6 is an explanatory diagram of an oval (egg-shaped) foreign material 30A. In this figure, the minimum outer diameter of the foreign matter 30A is L5, and the maximum outer diameter is L6. For the first embodiment, L1 shown in FIG. 2 is determined to correspond to L5, and t is set to a value larger than L6. On the other hand, the second embodiment can be dealt with by setting t shown in FIG. 5 to a value larger than L6.

  In the first and second embodiments described above, the multilayer coating 20 is formed on the valve body 10 side. However, in the present invention, on the contrary, the multilayer body 20 is formed on the valve body 3 side (the inner surface of the valve body support hole 5). The film 20 may be formed. In this case, it is preferable to use a material harder than the valve body 10 for the valve body 3.

  Furthermore, in the first and second embodiments described above, the valve body 10 is slid by an electromagnetic valve, but the present invention is not limited to this. For example, a configuration in which different pressures are applied to the proximal end side and the distal end side of the valve body 10 and the valve body 10 is slid by these pressure differences, or a pilot pressure is introduced from the hole 6a. Good.

  Furthermore, in the first and second embodiments described above, the sliding mechanism 8 of the hydraulic device 1 provided in the fluid injection device that injects water for lowering the combustion temperature into the cylinder of the marine engine is prevented from being seized. The present invention is not limited to this, and can be similarly applied to prevent seizure of other sliding mechanism portions such as a cylinder and a spool valve.

DESCRIPTION OF SYMBOLS 1 Hydraulic apparatus apparatus 3 Valve body 5 Valve body support hole 8 Sliding mechanism 10 Valve body 20 Multilayer coating 20a Outermost surface layer 21 Crevice 30 Spherical foreign matter 30A Oval spherical foreign matter t Thickness of multilayer coating L1 Gap size L2 Maximum outer diameter L4 Design clearance dimension L5 Minimum outer diameter of elliptical foreign material L6 Maximum outer diameter of elliptical foreign material

Claims (6)

The disc,
A support member having a valve body support hole for slidably supporting the valve body;
A multi-layered film formed in multiple layers on one of the inner surface of the valve body support hole and the outer surface of the valve body, and having a hard layer harder than the other as the outermost surface layer,
A sliding mechanism characterized in that the thickness of the multilayer coating is larger than the outer diameter of a foreign matter having the largest outer diameter among foreign matters that can enter a gap between the multilayer coating and the other.   The sliding mechanism according to claim 1, wherein the one side on which the multilayer coating is formed is harder than the other side.   3. The sliding mechanism according to claim 2, wherein the thickness of the multilayer coating is 0.5 times the outer diameter of the foreign material having the largest outer diameter among the foreign materials that can enter the gap between the multilayer coating and the other. A sliding mechanism characterized by being larger than. The disc,
A support member having a valve body support hole for slidably supporting the valve body;
A multi-layered film formed in multiple layers on one of the inner surface of the valve body support hole and the outer surface of the valve body, and having a hard layer harder than the other as the outermost surface layer,
A sliding mechanism characterized in that a thickness of the multilayer coating is larger than a designed gap dimension between the multilayer coating and the other.   5. The sliding mechanism according to claim 4, wherein the one side on which the multilayer film is formed is harder than the other side.   6. The sliding mechanism according to claim 5, wherein a thickness of the multilayer coating is larger than 0.5 times a designed gap dimension between the multilayer coating and the other.

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