TW201730462A - Sealing member for machine tools - Google Patents

Abstract

The sealing member for machine tools of the present invention comprises a supporting member and a plate-shaped elastic member which is integrated with the supporting member, wherein, in the plate-shaped elastic member, at least one of two surfaces facing each other in the thickness direction serves as an abutting surface an edge part of which abuts on a counterpart member, the sealing member being characterized in that the elastic member is formed of a composition containing a thermosetting polyurethane and inorganic particles and the inorganic particles are eccentrically located on the abutting surface side in the thickness direction of the elastic member.

Description

Working machine sealing parts

The present invention relates to a sealing member for a working machine.

In a working machine such as a lathe or a machining center, in order to protect the drive mechanism from being affected by chips or coolant (cutting oil), various sealing members for working machines, for example, lip seals, are used. , a slide seal, a telescopic seal, a cover seal, and the like. As the sealing member for a working machine, for example, a sealing material including a core metal and a nitrile rubber (NBR) containing sulfur added to the core metal is known.

In recent years, with the increase in the speed of the work machine, the sliding resistance of the seal member and the target member has become a problem. For example, in the sealing member for a machine tool, the sealing member and the target member are slid at a high speed, whereby a gap is easily formed between the sealing member and the target member, and as a result, the performance of the sealing member for the working machine is lowered (the chip or the coolant is easily exposed). And/or, the sealing material is curled by high-speed sliding, or a chattering sound is generated.

On the other hand, in order to reduce the sliding resistance of the sealing material and the target member, a sealing member for a work machine provided with a woven fabric or a knitted fabric at a sliding portion of the target member has been proposed (for example, Patent Document 1). In addition, a sealing member for a working machine in which an antifriction material such as an organic fiber is blended with a sliding portion of a target member is proposed (for example, Patent Document 2). Prior art literature

Patent Document 1: Japanese Laid-Open Patent Publication No. 2000-354934. Patent Document 2: Japanese Patent Laid-Open Publication No. 2009-202074

[Problems to be Solved by the Invention] However, in the sealing member for machine tools, there is a case where the sliding resistance cannot be sufficiently reduced, or the sealing performance can be lowered early even if the sliding resistance can be lowered.

The present invention has been made to solve such a problem, and an object of the invention is to provide a sealing member for a working machine which can achieve a reduction in sliding resistance of a target member and maintain sealing performance for a long period of time. [Means for solving the problem]

(1) The sealing member for a machine tool according to the present invention includes a support member and a plate-shaped elastic member integrated with the support member, wherein the plate-shaped elastic member is in two faces facing each other in the thickness direction. At least one surface is an abutting surface where the edge portion abuts against the target member, and the elastic member includes a composition containing a thermosetting polyurethane and an inorganic particle, and the inorganic particle is in the elastic member The thickness direction is biased to exist on the abutting surface side.

The elastic member of the sealing member for a work machine includes a composition containing a thermosetting polyurethane and inorganic particles (hereinafter also referred to as a urethane-based composition). Therefore, the sealing member for a working machine can improve the wear resistance by the thermosetting polyurethane, and the sliding resistance with the target member can be reduced by the inorganic particles. At this time, the inorganic particles are biased toward the sliding surface side of the elastic member, so that the sliding resistance can be surely lowered. Further, since the inorganic particles are biased, the elastic member is hardened by the inorganic particles in the sealing member for a machine tool, and as a result, physical properties such as appropriate elastic deformation required for the elastic member can be prevented from being damaged. Therefore, even when it is used under high-speed sliding conditions, the sealing member for a working machine can maintain the sealing performance for a long period of time, and can prevent generation of chattering sound or curling of the elastic member. Since the elastic member contains the urethane-based composition, it is less likely to be swollen by a coolant (cutting fluid) than an elastic member containing NBR or the like, and is excellent in coolant resistance.

(2) In the sealing material for a machine tool according to the above aspect, the plate-shaped elastic member is preferably configured such that the elastic member is divided into three outer sides and a first outer layer in the thickness direction. When the second outer layer and the intermediate layer interposed between the outer layers, the content of the inorganic particles in the first outer layer is larger than the content of the inorganic particles in the intermediate layer, and the first outer side is The outer surface of the layer is set as the abutting surface. In such a sealing material for a machine tool, since most of the inorganic particles are present on the contact surface side, the sliding resistance of the target member in the elastic member can be reduced without deteriorating the characteristics of the elastic member (appropriate elastic deformation or the like). Therefore, the sealing member for machine tools is more suitable for reducing the sliding resistance with the target member and ensuring excellent sealing properties over a long period of time.

(3) The sealing member for a machine tool according to (1) or (2) above preferably contains inorganic oxide particles or inorganic balls as the inorganic particles. The inorganic particles are adapted to be present in the elastic member. Further, the adhesion between the inorganic particles and the thermosetting polyurethane is also good.

(4) The work machine sealing member according to (1) or (2), which preferably contains cerium oxide particles as the inorganic particles and is 100 parts by weight with respect to the thermosetting polyurethane. The content of the cerium oxide particles is from 2 parts by weight to 20 parts by weight. The cerium oxide particles are easily compatible with the thermosetting polyurethane, and are excellent in chemical stability, and are also suitable for the reduction in the sliding resistance. Further, the cerium oxide particles are also preferably suitable for being present on the side of the abutting surface of the elastic member. Therefore, the sealing member for a working machine can effectively reduce the sliding resistance with the target member by containing the niobium particles in the above-mentioned content, and can secure excellent sealing performance for a longer period of time.

(5) The sealing member for a machine tool according to (2), wherein the content of the inorganic particles in the second outer layer is more than that of the inorganic particles in the intermediate layer. The content is such that the outer surface of the second outer layer is the abutting surface. Such a sealing member for a working machine can be suitably used, for example, in a thickness direction of the plate-shaped elastic member, such as a cover seal attached to a door portion of a machine tool. Both of the both surfaces are a sealing member for a working machine which is a contact surface with the target member.

(6) The sealing member for a working machine according to (5), which preferably contains inorganic oxide particles and inorganic beads as the inorganic particles, and the first outer layer contains more inorganic matter than the intermediate layer. The particles are any one of inorganic oxide particles and inorganic balls, and the inorganic particles more contained in the second outer layer than the intermediate layer are any one of inorganic oxide particles and inorganic balls. By including such two kinds of inorganic particles, the sealing member for a machine tool can reliably bias the inorganic particles to the first outer layer side and the second outer layer side existing in the elastic member, and can reliably reduce the respective resistances. Sliding resistance in the joint. Further, in the sealing member for a machine tool, since the content of the inorganic particles in the intermediate layer is small, the sealing performance can be maintained. [Effects of the Invention]

The sealing member for a working machine of the present invention can achieve a reduction in sliding resistance with respect to the target member, and can maintain excellent sealing performance for a long period of time.

(First embodiment) Hereinafter, a sealing material for a machine tool according to the present embodiment will be described. The sealing member for a machine tool according to the embodiment includes a support member and a plate-shaped elastic member integrated with the support member. Fig. 1 (a) is a plan view showing a sealing member for a machine tool according to a first embodiment, and Fig. 1 (b) is a side view of Fig. 1 (a). FIG. 2 is a cross-sectional view schematically showing a main part of an elastic member provided in the sealing member for a machine tool shown in FIGS. 1( a ) and 1 ( b ).

As shown in Fig. 1 (a) and Fig. 1 (b), the work machine sealing member 10 includes a support member 11 and an elastic member 12, and the support member 11 includes a substantially rectangular metal plate bent in the longitudinal direction. The metal plate is processed, and the elastic member 12 is a plate-shaped elastic member 12 that is fixed via the adhesive layer 13 in the longitudinal direction of the support member 11. The elastic member 12 is a plate-shaped member, and has a first surface 14 and a second surface 15 that face each other in the thickness direction (vertical direction in FIG. 2 ), and the edge portion 12 a of the first surface 14 (the elastic member 12 ) The vicinity of the edge portion formed by the first surface 14 and the distal end surface 12c is in contact with the target member. Thereby, the working machine sealing member 10 can seal a predetermined portion of the working machine. In the sealing member 10 for a machine tool, the first surface 14 is an abutting surface.

The elastic member 12 contains a composition containing a thermosetting polyurethane and inorganic particles. The inorganic particles 16 are dispersed in the elastic member 12. At this time, as schematically shown in FIG. 2, the inorganic particles 16 are biased to exist on the abutting surface 14 side. Specifically, the elastic member 12 is equally divided into the first outer layer 17A, the intermediate layer 18, and the second outer layer 17B in the thickness direction from the first surface (contact surface) 14 side toward the second surface 15 side. In the inorganic particles 16 , the inorganic particles 16 are mostly contained in the first outer layer 17A, the inorganic particles 16 in the intermediate layer 18 are contained, and the inorganic particles 16 are not present in the second outer layer 17B. In the first outer layer 17A, the content of the inorganic particles 16 gradually increases from the side of the intermediate layer 18 toward the abutting surface 14 side, and a part of the inorganic particles 16 is exposed on the side of the abutting surface 14 . Further, in the sealing material for machine tools of the present embodiment, only the first outer layer 17A may contain inorganic particles, and the second outer layer 17B and the intermediate layer 18 may be completely free of inorganic particles.

The work machine sealing member 10 having such an elastic member 12 is excellent in wear resistance by thermosetting polyurethane, and the sliding resistance against the target member is lowered by the inorganic particles 16. Therefore, even when used under high-speed sliding conditions, the sealing member 10 for a working machine can ensure excellent sealing performance for a long period of time.

The work machine sealing member 10 can be used, for example, as a telescopic seal. 3 is a cross-sectional view schematically showing a part of a telescopic cover to which a sealing member 10 for a working machine is attached. As shown in FIG. 3, the work machine sealing member 10 is fixed to the support member 11 by screwing (not shown) on the lower surface of the outer end portion of each of the cover members 110 constituting the telescopic cover 100. At this time, the work machine sealing member 10 is attached to a position where the outer surface 110a of the lower cover member 110 and the abutting portion of the elastic member 12 are surely slidably contacted. Further, a through hole (not shown) for a bolt is formed in advance on the support member 11. As described above, the telescopic cover of the work machine sealing member 10 is attached to the outer end portion of each of the cover members 110 to prevent the cutting powder or the like existing on the outer side of the telescopic cover from entering the cover during expansion and contraction of the telescopic cover.

In various working machines such as a lathe or a cutting machine, the sealing member 10 for a working machine can be used as a sealing member for protecting various components such as a driving mechanism in a working machine from cutting powder or coolant. The sealing member 10 for a working machine can be used not only as the telescopic seal but also as a lip seal, a slide seal, a cap seal, and the like.

Next, the constituent members of the sealing member for machine tools of the present embodiment will be described. (Supporting Member) The supporting member 11 is a member for reliably attaching the elastic member to the work machine. From the viewpoint of durability or strength, as the material of the support member 11, a metal material such as steel or aluminum is usually suitable. The material may also be ceramic or rigid plastic. Further, as the support member, a steel sheet having no surface treatment, a steel sheet subjected to surface treatment such as zinc phosphate treatment, chromate treatment or rust-proof resin treatment, an elastic metal plate such as phosphor bronze or spring steel, or the like may be used. In order to improve the compatibility with the adhesive layer, the support member may also be subjected to a surface treatment using a primer or a roughening treatment.

(Elastic Member) The elastic member 12 contains a composition (urethane-based composition) containing a thermosetting polyurethane and inorganic particles. Examples of the inorganic particles include inorganic oxide particles containing an inorganic oxide such as cerium oxide, zirconium oxide, zinc oxide, aluminum oxide, iron oxide or cerium oxide, and metals such as copper, nickel, iron, and aluminum. Metal powder; inorganic ball such as glass balloon or fly ash balloon. These inorganic particles may be used singly or in combination of two or more. In the present invention, the inorganic sphere means a hollow structure among particles containing an inorganic material. In addition, the inorganic oxide particles mean particles containing a metal oxide such as cerium oxide, a semimetal oxide such as cerium oxide, or a composite of these. Further, when the inorganic oxide particles have a hollow structure, they are distinguished from inorganic oxide particles as inorganic balls.

Among these inorganic particles, those which are suitable for being present in the elastic member and which are excellent in adhesion to the thermosetting polyurethane are preferably inorganic oxide particles and inorganic balls. In particular, it is preferably a cerium oxide particle because it is easily compatible with a thermosetting polyurethane, has excellent chemical stability, and is suitable for a reduction in sliding resistance. Since the cerium oxide particles are sufficiently heavy in specific gravity as compared with the thermosetting polyurethane, they are also suitable for being biased toward the abutting surface side of the elastic member.

The content of the inorganic particles may be appropriately selected depending on the type of the inorganic particles. For example, when the inorganic particles are cerium oxide particles, the content of the cerium oxide particles is preferably from 2 parts by weight to 20 parts by weight based on 100 parts by weight of the thermosetting polyurethane. When the content of the cerium oxide particles is less than 2 parts by weight, the sliding resistance may not be sufficiently lowered. On the other hand, when the content of the cerium oxide particles exceeds 20 parts by weight, the elastic member may be hardened and the sealing performance may be deteriorated. Further, even if the content of the cerium oxide particles exceeds 20 parts by weight, it is difficult to further reduce the sliding resistance. The content of the cerium oxide particles is more preferably from 3 parts by weight to 15 parts by weight per 100 parts by weight of the thermosetting polyurethane. Further, when the inorganic particles are inorganic balls, the content of the inorganic particles is preferably from 0.1 part by weight to 2.0 parts by weight based on 100 parts by weight of the thermosetting polyurethane. When the content of the inorganic sphere is less than 0.1 parts by weight, the sliding resistance may not be sufficiently lowered. On the other hand, when the content of the inorganic sphere exceeds 2.0 parts by weight, the elastic member may be hardened and the sealing performance may be deteriorated. Further, even if the content of the inorganic sphere exceeds 2.0 parts by weight, it is difficult to further reduce the sliding resistance. The content of the inorganic spheres is more preferably from 0.2 part by weight to 1.0 part by weight based on 100 parts by weight of the thermosetting polyurethane.

The particle diameter of the inorganic particles is preferably from 0.5 μm to 100 μm. When the inorganic particles are inorganic oxide particles, the particle diameter is preferably 0.5 μm to 10 μm, and when the inorganic particles are inorganic balls, the particle diameter is preferably 20 μm to 80 μm. When the particle diameter of the inorganic particles is small, the specific surface area of the inorganic particles is increased, and the flow resistance of the thermosetting polyurethane is increased, so that it may be difficult to be biased in the elastic member. On the other hand, when the particle diameter of the inorganic particles is large, the thermosetting polyurethane is likely to fall off during sliding, and the sliding resistance may not be stably maintained for a long period of time. The particle diameter of the inorganic particles is a value d50 when the cumulative particle size distribution is 50% by volume measurement using a laser diffraction type particle size distribution measuring apparatus (for example, manufactured by Seishin Co., Ltd., LMS-2000e, etc.). (median particle size) obtained. In the elastic member, such inorganic particles are biased in the thickness direction. A method of biasing the inorganic particles in existence will be described below.

In the present invention, the thermosetting polyurethane is a cured product obtained by curing a thermosetting urethane raw material containing a polyol component, an isocyanate component, and a crosslinking agent. The polyol component is not particularly limited, and examples thereof include a polyester polyol, a polyether polyol, and a polycaprolactone polyol. The number average molecular weight of the polyol is preferably from 1,000 to 3,000. The reason is that the sealing member for a working machine is more suitable for preventing entry of cutting powder, coolant, or the like. The number average molecular weight is a measured value in terms of polystyrene measured by a gel permeation chromatograph (GPC).

Examples of the polyester polyol include those obtained by reacting a dicarboxylic acid with a diol according to a conventional method. Examples of the dicarboxylic acid include aliphatic dicarboxylic acids such as terephthalic acid, isophthalic acid, and 2,6-naphthalenedicarboxylic acid; adipic acid, sebacic acid, and sebacic acid; An oxycarboxylic acid such as a carboxylic acid or an oxybenzoic acid, or an ester-forming derivative thereof. Among these, adipic acid is preferred in terms of good abrasion resistance.

Examples of the diol include ethylene glycol, 1,4-butanediol, diethylene glycol, neopentyl glycol, 3-methyl-1,5-pentanediol, and 1,9-fluorene. An aliphatic diol such as a diol or a triethylene glycol, an alicyclic diol such as 1,4-cyclohexanedimethanol, an aromatic diol such as p-xylene glycol, polyethylene glycol, polypropylene glycol or polytetraethylene A polyoxyalkylene glycol such as methylene glycol or the like. The diol is preferably an aliphatic diol, more preferably ethylene glycol or 1,4-butanediol. The polyester polyol which is a reactant of the dicarboxylic acid and the diol has a linear structure, but may be a branched polyester in which a trivalent or higher ester forming component is used.

Examples of the polyether polyol include polyalkylene glycols such as polyethylene glycol, polypropylene glycol, polytetramethylene glycol, and copolymers thereof. Among them, polytetramethylene glycol is preferred in terms of good abrasion resistance. Examples of the polycaprolactone polyol include those obtained by subjecting ε-caprolactone to ring-opening addition in the presence of a catalyst by using a low molecular weight diol as a starter.

These polyol components may be used singly or in combination of two or more. The polyol component is preferably a polyethylene adipate ester polyol (PEA). At this time, the elastic member is particularly excellent in coolant resistance. Therefore, the sealing member for a working machine including the elastic member can maintain performance for a longer period of time.

The polyisocyanate is not particularly limited, and examples thereof include an aliphatic isocyanate, an alicyclic isocyanate, and an aromatic isocyanate. Among these, an aromatic isocyanate is preferred in terms of good abrasion resistance. Examples of the aliphatic isocyanate include 1,6-hexamethylene diisocyanate (HDI), 2,2,4-trimethylhexamethylene diisocyanate, and isocyanuric acid diisocyanate. . Further, an isocyanurate body, a biuret body, a modified form of an adduct, or the like of hexamethylene diisocyanate or isophorone diisocyanate may also be mentioned. Examples of the alicyclic isocyanate include isophorone diisocyanate (IPDI), 4,4'-dicyclohexylmethane diisocyanate, 1,4-cyclohexane diisocyanate, and norbornane. An alicyclic diisocyanate such as norbornane diisocyanate (NBDI). Examples of the aromatic isocyanate include toluene diisocyanate (TDI), benzene diisocyanate, 4,4'-diphenylmethane diisocyanate (MDI), and 1,5-naphthalene diisocyanate. Xylylene Diisocyanate (XDI), carbodiimide-modified MDI, urethane-modified MDI, and the like. The polyisocyanate may be used singly or in combination of two or more.

Examples of the crosslinking agent include ethylene glycol, propylene glycol, butylene glycol, hexanediol, diethylene glycol, trimethylolpropane, glycerin, hydrazine, ethylenediamine, diethylenetriamine, and 4 4'-Diaminodiphenylmethane, 4,4'-diaminodicyclohexylmethane, N,N-bis(2-hydroxypropyl)aniline, water, and the like. Among these, in terms of good oil resistance, butylene glycol and trimethylolpropane are preferred. These crosslinking agents may be used singly or in combination of two or more.

In addition, the thermosetting urethane raw material may contain a reaction aid such as a chain extender, a crosslinking accelerator, a crosslinking retarder, a hydrolysis inhibitor, a colorant, a light stabilizer, a heat stabilizer, and the like. Antioxidants, antifungal agents, flame retardants, extenders, etc.

In the elastic member 12, the inorganic particles 16 are biased toward the abutting surface 14 side. The elastic member 12 having such a configuration can be produced, for example, by the following first method, second method, or the like.

(First Method) The thermosetting urethane raw material is mixed with the inorganic particles to prepare a raw material composition. Then, the obtained raw material composition is put into a centrifugal molding machine, and the thermosetting urethane raw material is thermally cured under predetermined conditions to form a cylindrical urethane-based composition. . Thereafter, the urethane-based composition is developed into a sheet shape and cut into a predetermined size, whereby an elastic member is produced.

In the first method, the inorganic particles may be biased by the difference in specific gravity between the thermosetting urethane raw material and the inorganic particles. In the first method, when the inorganic particles having a specific gravity higher than that of the thermosetting urethane raw material (for example, cerium oxide particles or the like) are blended, the inorganic particles can be made to be biased toward the elastic member which is present on the mold surface side of the molding machine. . On the other hand, when the inorganic particles (for example, inorganic spheres) having a specific gravity lower than that of the thermosetting urethane raw material are blended, the inorganic particles can be formed to be opposite to the side of the mold surface of the molding machine (hereinafter, also An elastic member called the air side).

(Second method) A raw material composition A in which the thermosetting urethane raw material and the inorganic particles are mixed, and a raw material composition B containing only the thermosetting urethane raw material are separately prepared . Next, any raw material composition of the obtained raw material composition A and raw material composition B is put into a centrifugal molding machine, and the thermosetting urethane raw material is semi-hardened under predetermined conditions. Then, another raw material composition that has not been charged is put into a centrifugal molding machine, and is cured under a predetermined condition to form a cylindrical urethane-based composition. Thereafter, the urethane-based composition is developed into a sheet shape and cut into a predetermined size, whereby an elastic member is produced.

In the second method, when the difference in specific gravity between the thermosetting urethane raw material and the inorganic particles is small, the inorganic particles may be biased. In the second method, when the inorganic particles having a specific gravity greater than that of the thermosetting urethane raw material are formulated as the inorganic particles, the raw material composition A containing the inorganic particles is first introduced. On the other hand, when the inorganic particles having a specific gravity lower than that of the thermosetting urethane raw material are formulated as the inorganic particles, the raw material composition B containing no inorganic particles is first introduced. Thereby, it is possible to produce an elastic member in which the inorganic particles are biased on either the mold surface side or the air side.

In the first method and the second method, the state in which the inorganic particles are deflected can be adjusted by preparing the molding temperature (hardening time), the rotational speed of the molding machine, and the like. Further, in the first method and the second method, the thermosetting urethane raw material before being introduced into the molding machine may directly contain an unreacted polyol component and an isocyanate component, or an amine obtained by the reaction of the two. The urethane prepolymer is included in the form. That is, the hardening of the thermosetting urethane raw material can be carried out by a one shot method or by a prepolymer method.

The hardness of the elastic member (Japanese Industrial Standards (JIS) A hardness) is preferably from 55 to 90. When the hardness of the elastic member is less than 55°, deformation may occur when sliding on the sliding surface of the machine tool, and intrusion of cutting powder or the like may not be reliably prevented. On the other hand, when the hardness of the elastic member exceeds 90°, the elastic member is too hard, and thus may be damaged during sliding. The hardness of the elastic member is more preferably 65 to 80. The JIS A hardness is a value measured in accordance with JIS K 7312 using a spring type A hardness tester.

The elastic member preferably has a rebound resilience of 10% to 50%. By setting the resilience of the elastic member to the above range, it is easier to suppress the occurrence of an abnormal sound (shock sound) at the time of sliding. The rebound resilience is preferably from 20% to 40%. The rebound resilience is a value measured in accordance with JIS K 7312.

(Adhesive Layer) The adhesive layer that fixes the elastic member and the support member is not particularly limited, and may be appropriately selected in consideration of the material of each member. Examples of the pressure-sensitive adhesive layer include an ethylene vinyl acetate copolymer (EVA)-based, a polyamide-based or a polyurethane-based hot-melt adhesive, or a hardening adhesive. The person formed by the above may further include a person formed by using a double-sided tape or the like. The thickness of the adhesive layer is not particularly limited, but is preferably 50 μm to 500 μm.

(Second Embodiment) In the sealing member for a machine tool according to the present embodiment, the state of dispersion of the inorganic particles in the plate-shaped elastic member is different from that of the first embodiment. Fig. 4 (a) is a side view showing a sealing member for a machine tool according to a second embodiment, and Fig. 4 (b) is a view schematically showing an elastic member of the sealing member for a working machine shown in Fig. 4 (a). Sectional view of the department.

As shown in FIG. 4( a ), the work machine sealing member 20 includes a plate-shaped support member 21 and a single-sided elastic member 22 that is fixed to the support member 21 via the adhesive layer 23 . The elastic member 22 is a plate-shaped member, and has a first surface 24 and a second surface 25 that face each other in the thickness direction (the horizontal direction in FIG. 4( a )), and the edge portion 22 a of the first surface 24 (elasticity) The edge portion 22b of the second surface 25 (the edge portion formed by the second surface 25 and the front end surface 22c of the elastic member 22) is in contact with the target member, and the first surface 24 of the member 22 is in contact with the target member. It is close to the target member. In the sealing member 20 for a machine tool, the first surface 24 and the second surface 25 are both abutting surfaces with the target member.

The elastic member 22 contains a composition containing a thermosetting polyurethane and inorganic particles, and the inorganic particles are dispersed in the elastic member 22 . At this time, the inorganic particles include two types of inorganic particles 26A and 26B. As shown in Fig. 4 (b), in the elastic member 22, the inorganic particles 26A are biased toward the abutting surface (first surface) 24 side, and the inorganic particles 26B are biased toward the abutting surface (second surface) 25 side. Specifically, the elastic member 22 is equally divided into the first outer layer 27A and the intermediate layer 28 in the thickness direction from the first surface (contact surface) 24 side toward the second surface (contact surface) 25 side. In the second outer layer 27B, the inorganic particles 26A and the inorganic particles 26B contain most of the inorganic particles 26A in the first outer layer 27A, and most of the inorganic particles 26B in the second outer layer 27B, and the intermediate layer 28 contains only a small amount. The way inorganic particles are biased exists. In the first outer layer 27A, the content of the inorganic particles 26A gradually increases from the intermediate layer 28 side toward the contact surface 24 side, and a part of the inorganic particles 26A is exposed on the contact surface 24 side. Further, in the second outer layer 27B, the content of the inorganic particles 26B gradually increases from the intermediate layer 28 side toward the abutting surface 25 side, and a part of the inorganic particles 26B is exposed on the contact surface 25 side. Further, in the sealing member for machine tools of the present embodiment, the intermediate layer 28 may be completely free of inorganic particles.

The sealing member 20 for a machine tool having the elastic member 22 is excellent in wear resistance by the thermosetting polyurethane, and the sliding resistance of the target member is changed by the inorganic particles 26A and the inorganic particles 26B. low. Therefore, the sealing member 20 for working machines can ensure excellent sealing performance for a long period of time. In addition, in the sealing member 20 for working machines, the first surface 24 and the second surface 25 are surfaces that are suitable for sliding against the target member. Therefore, the work machine sealing member 20 can be suitably used as, for example, a lid seal attached to a door of a work machine or the like.

The constituent member of the working machine sealing member of the present embodiment is substantially the same as the working machine sealing member of the first embodiment. However, in the elastic member 22, the first surface 24 side and the second surface 25 side are both biased. The aspect of the inorganic particles is different. In order to have such a configuration, the elastic member 22 contains two inorganic particles 26A and inorganic particles 26B as inorganic particles. Specifically, the elastic member 22 contains inorganic particles (for example, cerium oxide particles) having a specific gravity higher than that of the thermosetting urethane, and inorganic particles having a specific gravity lower than that of the thermosetting urethane (for example, oxidized spheres, etc.) ). Further, the inorganic particles having a large specific gravity are biased on either the first surface 24 side or the second surface 25 side, and the light-weight inorganic particles are biased to exist on the other side.

The elastic member 22 can be produced by the same method as the first method in the first embodiment. In other words, after the raw material composition is prepared by mixing the thermosetting urethane raw material and the two inorganic particles, the obtained raw material composition can be molded in the same manner as in the first method to produce an elastic member. . At this time, the inorganic particles having a large specific gravity can be produced to be present on the mold surface side of the molding machine, and the light-weight particles are biased toward the elastic member existing on the air side.

The elastic member 22 can also be produced, for example, by the following third method. (Third Method) A raw material composition A in which the thermosetting urethane raw material is mixed with inorganic particles having a specific gravity higher than that of the thermosetting urethane raw material, and the heat hardening are separately prepared The raw material of the urethane raw material is mixed with the inorganic particles having a specific gravity lower than that of the thermosetting urethane raw material. Next, the obtained raw material composition A is put into a centrifugal molding machine, and the thermosetting urethane raw material is semi-hardened under predetermined conditions. Then, the raw material composition B is placed in a centrifugal molding machine and cured under predetermined conditions to form a cylindrical urethane-based composition. Thereafter, the urethane-based composition is developed into a sheet shape and cut into a predetermined size, whereby an elastic member is produced. In the third method, the inorganic particles having a large specific gravity may be formed to be present on the mold surface side of the molding machine, and the light-weight particles may be biased toward the elastic member existing on the air side.

The working machine sealing member 20 can be used not only as a lid seal but also as a lip seal, a sliding seal, a telescopic seal, and the like in a work machine.

(Other Embodiments) The embodiments of the present invention are not limited to the embodiments, and may be appropriately modified within the scope of the invention described in the claims. When the elastic member provided in the sealing member for a working machine according to the embodiment of the present invention is halved in the thickness direction, the content of the inorganic particles is higher than the content of the other inorganic particles. Just fine.

In the sealing material for the working machine according to the embodiment of the present invention, the inorganic particles are not required to be present on the contact surface side of the plate-shaped elastic member as in the sealing member for the working machine of the first embodiment and the second embodiment. The sealing member for a working machine has inorganic particles only in a region in the vicinity of the abutting portion of the plate-shaped elastic member (for example, a region of 5 mm to 10 mm from the front end surface of the elastic member), and may be in the thickness direction of the region. The inorganic particles are biased to exist. At this time, the reduction in the sliding resistance of the target member and the maintenance of the long-term sealing property can be achieved. When the elastic member having such a configuration is produced, for example, a mold and two casting machines are prepared, and the raw material composition obtained by first mixing the thermosetting urethane raw material and the inorganic particles is cast to the abutting portion of the elastic member. And a portion located in the vicinity thereof, and secondly, a raw material composition containing only the thermosetting urethane raw material is cast to the remaining portion, and then hardened.

In the sealing member for a machine tool according to the first and second embodiments, the elastic member is integrally formed by centrifugal molding. However, the elastic member may have a content ratio of a plurality of inorganic particles (content per unit thickness). Sheets of different thermosetting polyurethanes and inorganic particles are bonded together by an adhesive. However, when a plurality of sheets are attached, it is difficult to ensure proper elastic deformation or strength, and there is also a possibility that the elastic members are warped. Therefore, the elastic member is preferably one containing a plate-like body (cured material) containing inorganic particles. [Examples]

Hereinafter, embodiments of the present invention will be specifically described by way of examples, but the present invention is not limited to the following examples. Here, an elastic member was produced and the characteristics were evaluated, and the friction coefficient was measured by manufacturing the sealing material for the working machine using the produced elastic member.

<Preparation of elastic member> (Preparation of urethane prepolymer) To polyethylene adipate diol (manufactured by Sanyo Chemical Industry Co., Ltd., San Ester 2620, hydroxyl value 56.1 30.5 parts by weight of pure MDI (manufactured by Tosoh Corporation, Millionate MT) was added to 100 parts by weight of mgKOH/g), and after degassing under reduced pressure at 70 ° C, the reaction was carried out while stirring. 8 hours, and prepolymer A was obtained.

(Preparation of the elastic member A) 1,4-BD (manufactured by Mitsui Chemicals, Inc., 1,4-butanediol), 6.37 parts by weight and TMP at 70 ° C were added to 100 parts by weight of the prepolymer A heated to 105 ° C. 0.197 parts by weight (manufactured by Mitsubishi Gas Chemical Co., Ltd.) and cerium oxide particles heated to 70 ° C (manufactured by Sun Miner Co., Cerico CH-601, particle size 2 μm) 5.32 by weight The mixture was stirred and mixed for 120 seconds to prepare a raw material composition A1. On the other hand, the raw material composition A2 was prepared in the same manner as the preparation of the raw material composition A1 except that the cerium oxide particles were not prepared. The raw material composition A1 was cast into a mold of a centrifugal molding machine heated to 155 ° C, and heated for 15 minutes to semi-harden the raw material composition A1. Then, the raw material composition A2 was placed in a centrifugal molding machine, and heated for 60 minutes to obtain a cylindrical cured product. Thereafter, one of the cylindrical cured products was cut into a plate shape, and post-crosslinked in a blowing oven at 110 ° C for 12 hours. Finally, the elastic member A is produced by cutting to a predetermined size. In the elastic member A, the thickness of the cured product obtained from the raw material composition A1 was 0.8 mm, and the thickness of the cured product obtained from the raw material composition A2 was 0.7 mm.

(Preparation of elastic member B) Cerico CH-BS302 (manufactured by Sun Miner Co., Ltd., particle size: 3 μm) was used as cerium oxide particles instead of Cerico CH-601, and The raw material composition B1 was prepared in the same manner as in the preparation of the raw material composition A1. Then, the elastic material B was produced in the same manner as the production of the elastic member A except that the raw material composition B1 was used instead of the raw material composition A1.

(Preparation of the elastic member C) The raw material composition C1 was prepared in the same manner as in the preparation of the raw material composition A1 except that the amount of the cerium oxide particles was changed to 15.99 parts by weight. Then, the elastic component C was produced in the same manner as the production of the elastic member A except that the raw material composition C1 was used instead of the raw material composition A1.

(Preparation of the elastic member D) 1,4-BD (manufactured by Mitsui Chemicals, Inc.) 6.37 parts by weight and TMP (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 0.197 at 70 ° C were added to 100 parts by weight of the prepolymer A heated to 105 ° C. The raw material composition D was prepared by weight-dispersing and 3.20 parts by weight of cerium oxide particles (manufactured by Sun Miner Co., Ltd., Cerico CH-BS302) heated at 70 ° C, and stirred for 120 seconds. Thereafter, the raw material composition D was cast into a mold of a centrifugal molding machine heated to 155 ° C, and heated for 60 minutes to obtain a cylindrical cured product. Thereafter, one of the cylindrical cured products was cut into a plate shape, and post-crosslinked in a blowing oven at 110 ° C for 12 hours. Finally, the elastic member D is produced by cutting to a predetermined size. Furthermore, the thickness of the elastic member D was set to 1.5 mm.

(Preparation of the elastic member E) 1,4-BD (manufactured by Mitsui Chemicals, Inc.) 6.37 parts by weight and TMP (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 0.197 at 70 ° C were added to 100 parts by weight of the prepolymer A heated to 105 ° C. 0.266 parts by weight of a glass beads balloon (manufactured by Ba Industrial Co., Ltd., borosilicate glass Q-cel 5020, particle size 60 μm), and a mixture of the mixture was stirred for 120 seconds to prepare a raw material composition. E. Thereafter, the raw material composition E was cast into a mold of a centrifugal molding machine heated to 155 ° C, and heated for 60 minutes to obtain a cylindrical cured product. Thereafter, one of the cylindrical cured products was cut into a plate shape, and post-crosslinked in a blowing oven at 110 ° C for 12 hours. Finally, the elastic member E is produced by cutting to a predetermined size. Furthermore, the thickness of the elastic member E was set to 1.5 mm.

(Preparation of the elastic member F) The raw material composition F was prepared in the same manner as in the preparation of the raw material composition E except that the amount of the glass beads was changed to 0.139 parts by weight. Then, the elastic material F was produced in the same manner as the production of the elastic member E except that the raw material composition F was used instead of the raw material composition E.

(Production of the elastic member G) In addition to the glass bead ball, a fly ash balloon (manufactured by Ba Industrial Co., Ltd., Centolite FS150 (20), particle size: 60 μm) was added in an amount of 1.07 parts by weight. The raw material composition G was prepared in the same manner as the preparation of the raw material composition E. Then, the elastic material G is produced in the same manner as the production of the elastic member E except that the raw material composition G is used instead of the raw material composition E.

(Preparation of elastic member H) In place of Cenolite FS150 (20), Centolite QK75 (manufactured by Babel Industrial Co., Ltd., particle size: 30 μm) was used as a floating bead, and in addition, it was composed of raw materials. Preparation of the material G The raw material composition H was prepared in the same manner. Then, the elastic material H was produced in the same manner as the production of the elastic member G except that the raw material composition H was used instead of the raw material composition G.

(Preparation of the elastic member I) 1,4-BD (manufactured by Mitsui Chemicals, Inc.) 6.37 parts by weight and TMP (manufactured by Mitsubishi Gas Chemical Co., Ltd.) 0.197 at 70 ° C were added to 100 parts by weight of the prepolymer A heated to 105 ° C. Parts by weight, and 0.266 parts by weight of glass beads (Q-cel5020) heated to 70 ° C and 3.20 parts by weight of cerium oxide particles (Cerico CH-BS302) were stirred and mixed for 120 seconds to prepare a raw material composition I. . Thereafter, the raw material composition I was cast into a mold of a centrifugal molding machine heated to 155 ° C, and heated for 60 minutes to obtain a cylindrical cured product. Thereafter, one of the cylindrical cured products was cut into a plate shape, and post-crosslinked in a blowing oven at 110 ° C for 12 hours. Finally, the elastic member I is produced by cutting to a predetermined size. Furthermore, the thickness of the elastic member I was set to 1.5 mm.

(Preparation of the elastic member J) The raw material composition J was prepared in the same manner as in the preparation of the raw material composition I except that 1.07 parts by weight of a floating bead (Cenolite QK75) was blended instead of the glass bead. Then, the elastic material J was produced in the same manner as the production of the elastic member I except that the raw material composition J was used instead of the raw material composition I.

(Production of Elastic Member K) Only the raw material composition A2 containing no inorganic particles was used, and an elastic member K having a thickness of 1.5 mm was produced. At this time, the raw material composition A2 was molded under the same conditions as those of the production of the elastic member D using the raw material composition D, and the elastic member K was produced.

<Evaluation of elastic member> (1) Evaluation of warpage Each elastic member (thickness: 1.5 mm) cut to 100 mm × 100 mm was placed on a platen in a direction in which the end surface was floated due to warpage. The maximum value of the end surface floating in this state was measured using a thickness gauge, and the amount of warpage was set. The results are shown in Table 1. In addition, when the amount of warpage in the evaluation is 0.4 mm or less, it can be suitably used as a sealing member for a working machine.

(2) Evaluation of resistance to coolant The weight of each elastic member (thickness: 1.5 mm) cut to about 10 mm × 20 mm was accurately weighed, and then immersed in a coolant at 50 ° C (trade name "Kelikot ( Clear Cut) RH-10P" (10-fold dilution of Nios). After the elapse of 200 hours, the elastic member was taken out, and the adhered coolant was wiped off, and the weight was accurately weighed again to calculate the weight increase rate (%) due to the immersion. The results are shown in Table 1. In addition, in this evaluation, when the weight increase rate is less than 10%, it can be judged that the coolant resistance is good.

(3) Confirmation of the state of inclusion of inorganic particles Each of the elastic members was sliced in three equal parts in the thickness direction using a microtome (Splitting machine NAF 470G) manufactured by Fortuna Co., Ltd., and cut into mold faces. Side layer (first outer layer), intermediate layer, and air side layer (second outer layer). Next, each layer was cut into about 10 mm × 10 mm to prepare a measurement sample. First, the weight (weight A) of each sample was accurately weighed. Thereafter, the sample was placed in a well-measured crucible, and heated in a high-temperature oven at 600 ° C / 1 hour. Thereby, the thermosetting polyurethane is burned. After cooling, the weight (weight B) of the combustion residue was accurately weighed and set to the weight of the inorganic particles. Based on the weight A and the weight B, the content of the inorganic particles in each layer with respect to 100 parts by weight of the thermosetting polyurethane was calculated by the following formula (1). The calculated value is accurate to one decimal place. The results are shown in Table 1. Content of inorganic particles (PHR) = [B / (A - B)] × 100 (1)

<Evaluation of Manufacturing and Dynamic Friction Coefficient of Working Machine Sealing Member> (Examples 1 to 10 and Comparative Example 1) Here, the working machine sealing member 20 having the structure shown in Fig. 4 was produced. First, a steel plate having a thickness of 0.8 mm (manufactured by Kobe Steel Co., Ltd., Green Coat GX-K2) was cut into 20 mm × 60 mm to obtain a plate-shaped support member 21.

Next, the elastic member 22 (any one of the elastic member A to the elastic member K) of 30 mm × 60 mm × 1.5 mm is fixed to the support via the adhesive layer (double-sided tape: manufactured by Nitto Denko Corporation, No. 500) 23 The member 21 is used to manufacture the sealing member 20 for the working machine. At this time, the elastic member 22 is fixed to the support member 21 so that the surface on the mold side at the time of production becomes the first surface 24 of the elastic member 22 in each of the elastic member A to the elastic member K. Further, the types of the elastic members used in the respective examples/comparative examples are shown in Table 1.

(Comparative Example 2) A commercially available sealing material for working machine (manufactured by Nitta Co., Ltd., LP-22ST) was used as an evaluation target.

(Comparative Example 3) A commercially available sealing material for working machine (manufactured by Nitta Co., Ltd., GW-LPV1) was used as an evaluation target.

With respect to the sealing members for working machines of Examples 1 to 10 and Comparative Examples 1 to 3, the dynamic friction coefficient was measured by the following method. The dynamic friction coefficient was measured using a Heidon type surface tester (HEIDON-14DR type, manufactured by Shinto Chemical Co., Ltd.). Fig. 5 (a) is a schematic view showing a method of measuring the dynamic friction coefficient of the sealing member for working machines of Examples 1 to 10 and Comparative Example 1, and Fig. 5 (b) is a view showing the operation of Measurement Comparative Example 2 and Comparative Example 3. Schematic diagram of a method of dynamic friction coefficient of a mechanical seal member.

The dynamic friction coefficient of the sealing member for working machine of Example 1 to Example 10 and Comparative Example 1 (1) The dynamic friction coefficient of the mold surface side is as shown in Fig. 5 (a), and the first surface 24 and surface of the elastic member 22 are processed. The angle formed by the surface 60a of the steel sheet 60 is 25°, and the contact portion 22a (edge portion) of the sealing member 20 for the work machine is brought into contact with the surface-treated steel sheet 60, and the upper side of the support member 21 faces downward in the vertical direction. The work machine sealing member 20 applies a vertical load of 100 g/20 mm width, and the abutting portion 22a is pressed against the surface-treated steel sheet 60. Thereafter, the surface-treated steel sheet 60 was horizontally moved at a moving speed of 25 mm/sec (the movement direction was from left to right in Fig. 5(a)), and the dynamic friction coefficient was calculated based on the following calculation formula. Dynamic friction coefficient = horizontal load average value / vertical load after 0.3 seconds after the start of sliding The results are shown in Table 1.

(2) Dynamic friction coefficient on the air side The dynamic friction coefficient on the air side was measured in the same manner as the measurement of the dynamic friction coefficient on the mold surface side, except that the vertical direction of the sealing member 20 for the working machine was reversed. In other words, the contact portion 22b (edge portion) on the second surface 25 side of the sealing member 20 for the machine tool is formed so that the angle formed by the second surface 25 of the elastic member 22 and the surface 60a of the surface-treated steel sheet 60 is 25°. The measurement was performed by contacting the surface-treated steel sheet 60.

Comparative Example 2 Comparative Example 3 with the machine tool kinetic friction coefficient of the sealing member in FIG. 5 (b), the angle of the lip 72 to the back surface of the surface 60a of a steel plate 60 formed in a manner to become a working machine 25 ° The edge portion 74 of the sealing member 70 is in contact with the surface-treated steel sheet 60, and a vertical load of 100 g/20 mm width is applied to the working machine sealing member 70 from the upper side of the core 71 in the vertical direction downward, and the edge portion 74 is applied. The surface-treated steel sheet 60 is crimped. Thereafter, the surface-treated steel sheet 60 was horizontally moved at a moving speed of 25 mm/sec (the movement direction was from left to right in Fig. 5(b)), and the dynamic friction coefficient was calculated based on the above calculation formula. The results are shown in Table 1.

The dynamic friction coefficient was measured in an environment of a temperature of 20 ° C to 25 ° C and a relative humidity of 40% to 55%. In addition, each measurement was carried out under dry conditions and under humid conditions. The measurement under dry conditions was carried out under dry conditions in which the surface 60a of the surface-treated steel sheet 60 was clean. On the other hand, the measurement under wet conditions is performed in a state where the surface 60a of the surface-treated steel sheet 60 is wetted by the coolant. Specifically, a portion of the surface-treated steel sheet that is in contact with the contact portion of the sealing member for the working machine is dropped with about 5 ml of a 10-fold diluted product of "Clear Cut RH-10P". . The measurement results of the dynamic friction coefficient were judged to be ○: 0.50 or less, Δ: more than 0.50 to 0.80 or less, and ×: more than 0.80, which are shown in Table 1.

[Table 1]

As shown in Table 1, it is understood that the elastic member containing the thermosetting polyurethane and the inorganic particles and having the inorganic particles deviated is hardly warped, and is excellent in coolant resistance. In the sealing member for a working machine including the elastic member, at least one of the two faces facing each other in the thickness direction has a low dynamic friction coefficient. Therefore, the sealing member for a machine tool according to the embodiment of the present invention can reduce the sliding resistance with the target member, and can secure the sealing performance for a long period of time.

10, 20, 70‧‧‧Working machine sealing parts
11, 21‧‧‧ Supporting materials
12, 22‧‧‧Flexible parts
12a, 22a, 22b‧‧‧ edge (abutment)
12c, 22c‧‧‧ front end
13, 23‧‧‧ adhesive layer
14, 24‧‧‧ first side (abutment)
15, 25‧‧‧ second side
16, 26A, 26B‧‧‧ inorganic particles
17A, 27A‧‧‧1st outer layer
17B, 27B‧‧‧2nd outer layer
18, 28‧‧‧ middle layer
60‧‧‧Surface processed steel plate
60a‧‧‧ surface
71‧‧‧core bone
72‧‧‧Lip
74‧‧‧Edge
100‧‧‧Retractable cover
110‧‧‧Cover parts
110a‧‧‧Outer surface

Fig. 1 (a) is a plan view showing a sealing member for a machine tool according to a first embodiment, and Fig. 1 (b) is a side view of Fig. 1 (a). FIG. 2 is a cross-sectional view schematically showing a main part of an elastic member provided in the sealing member for a machine tool shown in FIGS. 1( a ) and 1 ( b ). 3 is a cross-sectional view schematically showing a part of a telescopic cover to which the sealing member for a machine tool shown in FIGS. 1( a ) and 1 ( b ) is attached. Fig. 4 (a) is a side view showing a sealing member for a machine tool according to a second embodiment, and Fig. 4 (b) is a view schematically showing an elastic member of the sealing member for a working machine shown in Fig. 4 (a). Sectional view of the department. Fig. 5 (a) is a schematic view for explaining a method of measuring the dynamic friction coefficients of the sealing members for working machines of Examples 1 to 10 and Comparative Example 1, and Fig. 5 (b) is a view for explaining Comparative Example 2 A schematic view of a method of dynamic friction coefficient of a sealing member for a working machine of Example 3.

12‧‧‧Flexible parts

12a‧‧‧Fang Department (Abutment Department)

12c‧‧‧ front face

14‧‧‧1st face (abutment face)

15‧‧‧2nd

16‧‧‧Inorganic particles

17A‧‧‧1st outer layer

17B‧‧‧2nd outer layer

18‧‧‧Intermediate

Claims (6)

A sealing member for a working machine, comprising: a supporting member; and a plate-shaped elastic member integrated with the supporting member, wherein the plate-shaped elastic member is provided on at least one of two faces opposed in the thickness direction The sealing member for a working machine is characterized in that the elastic member includes a composition containing a thermosetting polyurethane and inorganic particles, and the inorganic particles are abutting surfaces that abut against the target member. It is biased toward the abutting surface side in the thickness direction of the elastic member. The sealing member for a machine tool according to the first aspect of the invention, wherein the plate-shaped elastic member is configured to divide the elastic member into a first outer layer and a second outer side in the thickness direction. When the outer layer and the intermediate layer are interposed between the outer layers, the content of the inorganic particles in the first outer layer is greater than the content of the inorganic particles in the intermediate layer, and the The outer surface of the outer layer 1 is set as the abutting surface. The sealing member for a machine tool according to the first or second aspect of the invention, comprising inorganic oxide particles or inorganic particles as the inorganic particles. The sealing member for a machine tool according to the above aspect of the invention, comprising cerium oxide particles as the inorganic particles, and 100 parts by weight relative to the thermosetting polyurethane The content of the cerium oxide particles is from 2 parts by weight to 20 parts by weight. The sealing member for a machine tool according to claim 2, wherein a content of the inorganic particles in the second outer layer is larger than a content of the inorganic particles in the intermediate layer, and The outer surface of the second outer layer is referred to as the abutting surface. The sealing member for a machine tool according to claim 5, comprising inorganic oxide particles and inorganic beads as the inorganic particles, and the first outer layer contains more inorganic particles than the intermediate layer. In any one of the inorganic oxide particles and the inorganic ball, the inorganic particles further contained in the second outer layer than the intermediate layer are any of the inorganic oxide particles and the inorganic particles. One.