JPS63186076A - Valve body for valve - Google Patents

Abstract

PURPOSE:To make the application of lubricant unnecessary, by making the sliding surface of a valve body, of a ceramic porous body, and impregnating grease in the opened pores of the valve body. CONSTITUTION:The valve body is made by forming its original material, a ceramic powder, in a desired formation, and a ceramic porous body is made up by combining pores on the formation without blocking them. Then, by impregnating grease in the opened pores of the ceramic porous body, the valve body is manufactured. The ceramic powder as the material is preferable to have the mean particle diameter less than 10mum, and selected from Al2O3, SiO2, ZrO2, SiC, TiC, TaC, and the like, or compounds of them.

Description

Detailed Description of the Invention [Industrial Application Field] The present invention relates to a valve body for communicating or blocking a fluid passage, and in particular, the present invention relates to a valve body that communicates or blocks a fluid passage. This invention relates to a valve body for a valve.

[Prior Art] By operating a control lever, a movable valve body is moved relative to a fixed valve body housed in a valve body while in sliding contact with the fixed valve body, thereby opening or closing a fluid passage. Many valves that control switching, adjustment, mixing, etc. have already been proposed.

By the way, there are various demands for this type of valve, such as the following.

■Even if the fixed valve body and movable valve body are in constant sliding contact, the operation lever must be easy to operate.

■Easy operation using the control lever can be maintained for a long period of time.

■Maintenance of each valve body should be easy and, if possible, completely unnecessary.

■Of course, the adhesion between each valve body does not change, and there is no fluid leakage even after long-term use.

■Each valve body is easy to manufacture.

In various valves for fluids that have been proposed in the past, such as valves for hot and cold water mixing faucets, each valve element is made of metal or aluminum oxide sintered material, taking into consideration the wear resistance between each valve element. Many of them were formed in a dense state using relatively hard materials such as.

In this way, the abrasion resistance of each valve element Q# is improved, but the sliding movement between the valve elements does not become smooth, and the sliding torque applied to the operating lever of the hot water mixing faucet becomes considerably large in the initial stage. Therefore, to ensure smooth sliding, a lubricant is applied to the surface of each valve body. However, the lubricant applied to the surface tends to flow out, making it difficult to maintain the initial operating characteristics after long-term use.

[Problems to be solved by the invention] As described above, although ceramics themselves have high hardness and excellent wear resistance, they generally lack self-lubricating properties. This material has not yet been proposed as a material that can be used as a valve body.

The present invention has been made in view of the above-mentioned circumstances, and its purpose is to always make the fluid communication/cutoff operation by the operating lever easy and easy even when used for a long period of time.
Another object of the present invention is to provide a valve body for a valve that can be operated in a stable state.

[Means for solving problems] The present invention will be explained in detail below.

The valve body of the present invention is a fixed valve body that is fixedly housed in a valve body to form a fluid flow path, or is moved relative to the fixed valve body while in contact with the above-mentioned fixed valve body by an operating lever of the valve body. It is used for at least one of the movable valve bodies that communicate or block the passage of the fixed valve body, and at least one sliding surface portion has open pores with a three-dimensional network structure. This valve body is characterized in that the open pores of a porous ceramic body are impregnated with grease.

However, in the valve body of the present invention, ceramic powder as a starting material is formed into a formed body of a desired shape, and the pores present in the formed body are bonded to each other without clogging, thereby forming a ceramic porous body. It can be manufactured by impregnating grease into the open pores of the ceramic porous body.

Various methods can be used to form the ceramic powder into a desired shaped body and to bond without clogging the pores present in the formed body. For example, the ceramic powder itself may be sintered under pressure. Alternatively, a method of self-sintering by pressure sintering, a method of adding a substance that generates ceramics by reaction to ceramic powder and performing reaction sintering, a method of bonding metals such as Co, Ni, Mo, or glass cement to ceramic powder. A method of blending a ceramic powder with a thermosetting resin or a thermoplastic resin as a binder and bonding by normal pressure sintering or pressure sintering, etc. can be applied.

Advantageously, the ceramic porous body has an open porosity of 5 to 50% by volume. The reason for this is that if the open porosity is lower than 5% by volume, the actual amount of grease impregnated will be small and it will be difficult to fully demonstrate the lubricating properties, whereas if it is higher than 50% by volume, This is because not only the strength of the porous body is low and particles are easily detached, but also the grease is easy to flow out.

It is advantageous that the average pore diameter of the ceramic porous body is 201 Lm or less. The reason for this is that when the average pore diameter is larger than 20 μm, the surface roughness of the porous body surface tends to increase, and while grease impregnation is easy, it is also easy to flow out, making it difficult to obtain stable Vtta torque. This is because the sliding characteristics deteriorate.

The ceramic powder that is the starting material has an average particle size of I
It is advantageous that the OILm is less than or equal to OILm. The reason for this is that when ceramic powder with an average particle size larger than 10 μm is used, there are fewer bonding points between the particles, which not only makes it difficult to produce a high-strength porous body, but also makes it difficult to produce a high-strength porous body. This is because the roughness deteriorates and the sliding torque increases.

The ceramics include Al t O3,5iO
z, ZrO□, SiC, TiC, TaC, B, C, W
C, Cri C2, Si: + N4, BN.

TiN, AmiN, TiB2. It is preferable that the ceramic porous body mainly contains one or more selected from CrBz, ZrB*, Sialon, or compounds thereof. The reason is that these ceramics have high hardness, excellent wear resistance, and high strength.
, S i C1Si3N4. ZrO, TiC, AI
Ceramics made of N and sialon are more suitable.

The valve body of the present invention is obtained by impregnating the open pores of the ceramic porous body produced as described above with grease. The reason for this is that by incorporating at least one of the greases mentioned below with excellent retention and lubrication properties into the ceramic base material, which has excellent wear resistance, the sliding properties can be significantly improved. be.

The greases include silicone grease, diester grease, phosphate ester grease, hindered ester grease, chlorofluorocarbon grease, silicate ester grease, fluoroether grease, polyphenyl ether grease, and hydrocarbon grease. It is advantageous to use one or a mixture of two or more selected from greases. Among these, silicone-based grease, chlorofluorocarbon-based grease, and fluoroether-based grease have excellent corrosion resistance and temperature stability, and are more suitable for obtaining stable sliding torque.

Methods for impregnating grease into the open pores of the porous ceramic body include methods of immersing the porous ceramic body in a lubricant whose viscosity has been reduced by heating and impregnating it under vacuum or pressure, and dispersing it in a soluble solvent. General methods such as impregnating a sample can be applied.

In this case, it is advantageous that the grease is impregnated into the porous body from the sliding surface to a depth of at least 5 μm. The reason for this is that if the depth of the grease impregnation is less than 5 gm, the grease may leak out relatively quickly and the torque may increase when the valve is used for a long period of time.

The hardness of the grease is preferably 700 or less in terms of consistency, because if the consistency is greater than 700, the grease becomes soft and leaks easily from the impregnated pores. A grease having a hardness of 500 or less is more suitable because leakage from the ceramic pores is extremely reduced, allowing the valve to be used for a long period of time.

Further, it is preferable that the pores of the porous body other than the pores impregnated with the grease are impregnated with oil having a viscosity of 1 to 100 lopoise. The reason is that the valve body is impregnated with oil.

This is because not only can leakage of fluid be suppressed, but also the oil expands due to temperature changes, and the grease can be supplied to the sliding surfaces, making it possible to provide more stable torque. Preferably, it is impregnated with 500 poise oil.

It goes without saying that the grease may contain a solid lubricant such as a fluororesin, graphite, molybdenum disulfide, graphite fluoride, and the like.

The hardness of the grease is preferably 700 or less in terms of consistency. The reason is that when the consistency is greater than 700, the grease becomes softer and more easily exposed than impregnated pores. A grease having a hardness of 500 or less is more suitable because the amount of exposure from the ceramic pores is extremely reduced, allowing the valve to be used for a long period of time.

Further, it is preferable that the pores of the porous body other than the pores impregnated with the grease are impregnated with oil having a viscosity of 1 to 1000 voids. The reason for this is that impregnated with oil not only prevents fluid from leaking from the valve body, but also expands the oil due to temperature changes and supplies the grease to the sliding surfaces, making it more stable. This is because it can give a high torque, and in particular, it is impregnated with oil with 2 to 500 voids.
preferable.

It goes without saying that the grease may contain a solid lubricant such as a fluororesin, graphite, molybdenum disulfide, graphite fluoride, and the like.

[Action of the Invention] The valve body of the present invention has the following effects by being configured as described above.

First, by forming the sliding surface of at least one of the fixed valve body and the movable valve body with a ceramic porous body, the ceramic porous body itself has high hardness and excellent wear resistance. Therefore, the wear resistance of both the fixed valve body and the movable valve body is improved.

Furthermore, the sliding surface of at least one of the fixed valve body and the movable valve body is formed of a ceramic porous body having open pores having a three-dimensional network structure, and the open pores are impregnated with grease. The lubricity of this grease ensures smooth sliding contact between the fixed valve body and the movable valve body for a long period of time.

This actual lubrication property is achieved by making the fixed valve body an alumina sintered body and the movable valve body a silicon carbide porous body impregnated with perfluoropolyether grease. At the same time, when considering the experimental results in the case of a ball valve in which these were assembled inside, the results were as shown in Fig. 1. In this experiment, in order to check the lubricity on the sliding surface between the fixed valve body and the movable valve body,
This was done by measuring sliding torque fluctuations on the operating lever of the ball valve. According to this experiment, even if the operating lever was moved 500,000 times, the sliding torque (A in Figure 1) applied to the operating lever was always less than 3 kgf-cm. The sliding torque fluctuation range is approximately 1 kgf.
-CrrI2 or less. In other words, compared to the sliding torque change* (portion in Figure 1) of the operating lever in conventional ball valves, when the valve body according to the present invention is used, the sliding torque on the operating lever is Not only is the torque low, but there is almost no sliding torque fluctuation even after long-term use.

Of course, the above also applies to liquids such as oil, various cleaning liquids, and various solutions, or various gases as the fluid.

Further, in place of the silicon carbide porous body described above, another ceramic porous body, ie, Al 20x .

Sio□, Zr0t, TiC, TaC, B4C1W
C, Cr3C2, S lz N4, BN, TiN, A
9. Even in the case of using a ceramic porous body mainly containing one or more selected from N, TiB2, CrB2, Sialon, or these compounds, almost the same effect as described above can be obtained. It is something.

In addition, in this valve, each fixed valve element or movable valve element itself contains lubricant, so there is no need for maintenance such as periodically applying lubricant to each valve element as in the past. It is.

(Example) Next, Examples and Comparative Examples will be described in which fixed valve bodies and movable valve bodies mainly made of ceramics are manufactured using silicon carbide.

Example 1 The silicon carbide powder used as a starting material consisted of 96% by weight of β-type crystals, 0.29% by weight of free carbon, and 0.29% by weight of free carbon.
It mainly contained 17% by weight oxygen, 0.03% by weight iron, 0.03% by weight aluminum, and had an average particle size of 0.28 μm.

5 parts by weight of polyvinyl alcohol and 300 parts by weight of water were blended with 100 parts by weight of silicon carbide powder, mixed in a ball mill for 5 hours, and then dried.

After taking an appropriate amount of this dry mixture and granulating it.

It was molded using a metal mold at a pressure of 3QOO kg/cm'. The dimensions of this generated form are 50mm x
50mm x 30mm, density 2.0g/cm''
(62% by volume).

The formed body was placed in a graphite crucible and fired in a Tammann type firing furnace in an atmosphere of mainly argon gas at 1 atm. The heating process was 450℃/hour for 200℃.
Raise the temperature to 0℃ and raise the maximum temperature to 10℃
It was maintained for a minute.

The density of the obtained porous body is 2.80 g/crn
', the open porosity was 13% by volume, and the average pore diameter was 4JLm, and its crystal structure, when observed with a scanning electron microscope, had a three-dimensional network structure in which silicon carbide crystals were intricately entangled in multiple directions. The average bending strength of the porous body is 58
．． It showed an extremely high value of 5 kg f/mm''.

This porous body was processed into a ring shape with an outer diameter of 30 mm, an inner diameter of 15 mm, and a thickness of 5 mm, and the consistency was 23 mm.
0 perfluoropolyether under vacuum. The perfluoropolyether impregnated into this porous body was impregnated to a depth of 5601 Lm from the sliding surface.

Using this perfluoropolyether-impregnated porous body as the movable side, an underwater sliding test was performed on the fixed side of an alumina ceramic valve body with a purity of 96% and a density of 3.75 g/cm' to 0.0.
When sliding was performed at a sliding speed of 05 cm/sec and an end face load of 10 kgf/cm', the sliding torque was 1.5 to 2.5 k as shown in Figure 1.
gf-cm, and after 500,000 times of sliding, the movable side ceramic had a wear seam of 0.8 μm, and it was recognized that it had extremely excellent sliding characteristics.

The porous body was the same as in Example 1, but when a sliding test was conducted without impregnating it with the grease, the sliding torque was 8 to 15 kgf/cm, and the sliding torque was 20,000 kgf/cm. During rotation and sliding, 3 meters of wear was already observed on the movable side.

Stream side 2 to 5, Comparative Examples 2 and 3 Same as Example 1, but as the material of the porous ceramics, 99% purity A text, 03,5iO2 (20 parts by weight) + BN (80 parts by weight), part It was made into stabilized ZrO2 and produced by firing at 1400-1800°C in a brewing atmosphere. This porous body was similarly impregnated with grease and subjected to a sliding test. Table 1 shows the results.

As shown in Table 1, it can be seen that the valve body of the present invention has excellent sliding characteristics.

Examples 6 to 1O Same as Example 1, but as materials for porous ceramics, TiC (90 parts by weight) + B4C (5 parts by weight), Z
rBz (80ifi parts') +C (5 parts by weight) +B
(155 parts by weight), TiB (95 parts by weight)
Ot (5 parts by weight) in an argon atmosphere at 1800
~2100°C, Si3N4 (90 parts by weight) + Z r
02 (4 parts by weight) + Y20:l (1 part by weight)
Produced by firing +Ai, O, (3 parts by weight) +BaO (2 parts by weight), A-N (95 parts by weight) + Y20:I (5 parts by weight) at 1700°C and 1500°C, respectively, in a nitrogen atmosphere. . Table 1 shows the results of a test conducted in the same manner as in C, using this porous body as the moving side and 5US-304 as the stationary side.

Examples 11 to 15, Comparative Example 4 The same as Example 1, or a case where the consistency of the grease was changed to 80 to 900, and a case where the consistency of the grease was changed to 80 to 900, and a case where dimethylpolysiloxane grease (m degree 250
), when impregnated with ethylene glycol (50 parts), 10 ethylhexyl sebacate (51 Li 1 part) (84 degrees 400), and when mineral oil with a viscosity of 1O voids is impregnated into the grease-unimpregnated parts of the pores of porous ceramics. The sliding results are also summarized in Table 1.

[Effects of the Invention] As detailed above, according to the present invention, the sliding surface portion of at least one of the fixed valve body and the movable valve body is made of a ceramic porous body having open pores with a three-dimensional network structure. The feature lies in the fact that the open pores are impregnated with grease, which makes it possible to perform communication/blocking operations using the operating lever even when the fixed valve body and the movable valve body are in constant sliding contact. It is possible to provide a valve body that is always light and can be operated in a stable state.

In a valve using the valve body formed in this way, not only can the operating lever be easily operated over a long period of time, but also the fixed valve body and the movable valve body can be slid in close contact with each other. is maintained for a long period of time 11r1, and there is no possibility of fluid leakage.

Of course, the above also applies to all types of valves that connect or shut off passages for fluids other than water or hot water, such as liquids such as oil, or gases such as propane gas. . Further, in applying the present invention, Alz Oy, Si
02,Z rot,S iC,T iC,TaC,B
4 C, WC, Cr3C2, 5t3N4. BN, TiN
, Amon, TiB2, CrB2, Sialon, or any one or more of these compounds.

In addition to forming the entirety of each fixed valve body or movable valve body as described above, at least only the surface portions of each fixed valve body or movable valve body that are in sliding contact with each other may be formed as described above. A similar effect can also be obtained if

[Brief explanation of the drawing]

Figure 1 shows the results of a long-term sliding test of a fixed valve body and a movable valve body.

Claims (1)

[Claims] 1) At least one sliding surface portion is a ceramic porous body having open pores with a three-dimensional network structure, and the open pores are impregnated with grease. Valve body for valves with special features. 2), the ceramic porous body is Al_2O_3, S
iO_2, ZrO_2, SiC, TiC, TaC, B_
4C, WC, Cr_3C_2, Si_3N_4, BN,
TiN, AllL, TiB_2, CrB_2, ZrB_2
2. The valve body according to claim 1, which mainly contains one or more selected from , Sialon, and their compounds. 3) The valve body for a valve according to claim 1 or 2, wherein the porous ceramic body has a porosity of 5 to 50% by volume. 4) The average pore diameter of the ceramic porous body is 20μ
The valve body according to any one of claims 1 to 3, which has a diameter of less than m. 5) The grease is silicone based grease, diester based grease, phosphate ester based grease, hindered ester based grease, chlorofluorocarbon based grease, silicate ester based grease, fluoroether based grease, polyphenyl ether based grease, carbonized The valve body according to any one of claims 1 to 4, which is at least one selected from hydrogen-based grease. 6) The valve body according to any one of claims 1 to 5, wherein the hardness of the grease is 700 or less in terms of consistency. 7) The grease is applied at least 5 times inward from the sliding surface.
Claims 1 to 3 are impregnated to a depth of μm.
The valve body for a valve according to any one of Item 6. 8) The valve body for a valve according to claim 7, wherein pores other than the pores impregnated with grease of the ceramic porous body are impregnated with oil having a viscosity of 1 to 1000 poise.