Patent Publication Number: US-2020282433-A1

Title: Machine tool wiper and method for manufacturing machine tool wiper

Description:
TECHNICAL FIELD 
     The present invention relates to a wiper for a machine tool and a method for manufacturing a wiper for a machine tool. 
     BACKGROUND ART 
     Conventionally, in order to prevent biting a foreign substance such as chips in a sliding surface of a machine tool such as a lathe and a milling machine, a wiper for a machine tool has been used (for example, Patent Literature 1). The wiper for a machine tool is mounted on a body part that reciprocates relative to the sliding surface such as a cover surface and a machine base surface of the machine tool. The wiper for a machine tool according to Patent Literature 1 described above includes a wiper body provided with a mounting member to be mounted on the machine tool, and a lip part formed on a lower end of the wiper body. The mounting member is mainly made of a metal plate. The wiper body and the lip part are each made of an elastic material. The mounting member on which an adhesive is applied is disposed in a die, and the die is filled with the elastic material, so that the wiper for a machine tool is integrally molded. 
     CITATION LIST 
     Patent Literature 
     Patent Literature 1: International Publication No. 2015/099087 
     SUMMARY OF INVENTION 
     Technical Problem 
     In a case of the above Patent Literature 1, there is a problem that the mounting member requires pretreatment work such as cutting of the metal plate, degreasing and strain elimination of the surface, burr polishing, and application of adhesive, and the number of manufacturing processes is increased. 
     An object of the present invention is to provide a wiper for a machine tool and a method for manufacturing a wiper for a machine tool, which can simplify a manufacturing process. 
     Solution to Problem 
     A wiper for a machine tool according to the present invention is a wiper for a machine tool mountable on a machine tool, the wiper for a machine tool including: a wiper body fixable to the machine tool, and made of a first elastic material having hardness of 80 degrees or more; and a sliding part made of a second elastic material containing a particulate reinforcing material and having hardness in a range of 50 degrees or more and 90 degrees or less which is smaller than the hardness of the first elastic material, the sliding part being provided integrally with the wiper body, wherein the wiper body and the sliding part are integrally formed without an adhesive. 
     A method for manufacturing a wiper for a machine tool according to the present invention is a method for manufacturing a wiper for a machine tool to be mounted on a machine tool, the wiper for a machine tool being obtained by integrally forming a wiper body and a sliding part without an adhesive, the wiper body being made of a first elastic material having hardness of 80 degrees or more, the sliding part being made of a second elastic material containing a particulate reinforcing material and having hardness in a range of 50 degrees or more and 90 degrees or less which is smaller than the hardness of the first elastic material, the method including: concurrently extruding the first elastic material and the second elastic material from openings of an extrusion die; and solidifying the first elastic material and the second elastic material extruded from the openings of the extrusion die. 
     Advantageous Effect of Invention 
     According to the present invention, it is possible to manufacture a wiper for a machine tool in which a wiper body made of a first elastic material and a sliding part made of a second elastic material are integrated by extrusion molding, and therefore a metal plate is not used unlike a conventional one, resulting in simplification of a manufacturing process. 
    
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         FIG. 1  is a perspective view illustrating a configuration of a wiper for a machine tool according to this embodiment; 
         FIG. 2  is a perspective view illustrating a configuration of a wiper for a machine tool according to Modification (A); 
         FIG. 3  is a side view illustrating a configuration of a wiper for a machine tool according to Modification (B); 
       Each of  FIGS. 4A and 4B  is a side view illustrating a configuration of a wiper for a machine tool according to Modification (C), in which  FIG. 4A  illustrates Modification C 1 , and  FIG. 4B  illustrates Modification C 2 ; and 
       Each of  FIGS. 5A, 5B, 5C and 5D  is a side view illustrating a configuration of a wiper for a machine tool according to Modification (D), in which  FIG. 5A  illustrates Modification D 1 , and  FIG. 5B  illustrates Modification D 2 ,  FIG. 5C  illustrates Modification D 3 , and  FIG. 5D  illustrates Modification D 4 . 
     
    
    
     DESCRIPTION OF EMBODIMENTS 
     Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. A wiper for a machine tool  10 A illustrated in  FIG. 1  includes a wiper body  12 , and a sliding part  14  provided integrally with the wiper body  12 . In the wiper for a machine tool  10 A, the wiper body  12  is mounted on a machine tool (not illustrated) so as to reciprocate relative to a scraping surface  11  such as a cover surface and a machine base surface of the machine tool (in the arrow direction in the drawing). 
     The wiper body  12  is a long plate-like member made of a first elastic material. As the first elastic material, hard resin or hard rubber having hardness of 80 degrees or more and 100 degrees or less can be used. The hardness of the first elastic material is preferably 85 degrees or more, more preferably 90 degrees or more. As the hard resin, for example, a resin material such as rigid polyvinyl chloride, ABS, PET can be used. As the hard rubber, for example, a rubber material such as NBR, urethane rubber, fluororubber, H-NBR, and carboxylated nitrile rubber (X-NBR) can be used. The resin or rubber material preferably has oil resistance, and has suitable elasticity in a range of hardness of 90 degrees or more. The hardness in this specification means Shore A hardness measured by a type A durometer on the basis of JIS K6253. 
     The sliding part  14  is a long plate-like member having the same length as the wiper body  12  made of a second elastic material, and is integrally fixed to one of long sides of the wiper body  12 . The sliding part  14  may be formed so as to be inclined at a predetermined angle (for example, about 100° to 150°) with respect to the short direction of the wiper body  12 . 
     As the second elastic material, soft resin or soft rubber having hardness of 50 degrees or more which is smaller than the hardness of the first elastic material can be used. The hardness of the second elastic material is preferably 55 degrees or more and 90 degrees or less, more preferably 60 degrees or more and 85 degrees or less. As the soft resin, for example, a resin material such as soft vinyl chloride and urethane can be used. As the soft rubber, for example, a rubber material such as NBR, urethane rubber, fluororubber, H-NBR, and carboxylated nitrile rubber (X-NBR) can be used. The rubber material preferably has oil resistance. 
     In the sliding part  14 , a certain ratio of a material for reinforcement, and a solid lubricating resin material are added as the reinforcing material to the aforementioned elastic material. As the material for reinforcement, a particulate polyethylene resin particle material, a particulate silica particle material, a particulate silica-alumina particle material, or the like can be used. As the solid lubricating resin material, a particulate acrylic-modified silicone resin particle material, a particulate polytetrafluoroethylene resin particle material, a particulate nylon resin particle material, or the like can be used. When the addition amount of each of the material for reinforcement and the solid lubricating resin material is too small compared to the constant ratio, mixed distribution to the rubber material becomes uneven, and a seal performance maintaining effect of the wiper for a long period is sometimes reduced. Additionally, when the addition amount of each of the material for reinforcement and the solid lubricating resin material is too much compared to the constant ratio, extrusion molding becomes difficult. 
     The wiper body  12  and the sliding part  14  are integrated such that long sides abut on each other. A joining part  18  where the wiper body  12  and the sliding part  14  are in contact with each other has a joint structure in which joints  20 ,  22  protruding toward each other are formed. The wiper body  12  has the joint  22  that protrudes toward the sliding part  14 , at one of the long sides. In this embodiment, the joint  22  of the wiper body  12  is forked with space at the center in the thickness direction, and a protrusion that protrudes in the thickness direction is formed at a leading end. The joint  20  of the sliding part  14  protrudes from a substantial center in the thickness direction, and is formed in a substantial T-shape. Thus, the joint structure is formed such that the joints  20 ,  22  engage with each other. The respective joints of the wiper body  12  and the sliding part  14  are integrated by vulcanized adhesion. 
     Now, a method for manufacturing the wiper for a machine tool  10 A configured described above will be described. The wiper for a machine tool  10 A is manufactured through respective processes of material preparation, extrusion, solidification, and cutting. First, a resin pellet material, and a material for reinforcement and a solid lubricating resin material, or an unvulcanized rubber material obtained by kneading raw rubber, and a mixed material obtained by adding a material for reinforcement and a solid lubricating resin material to the above rubber material are produced, so that an unvulcanized first elastic material and an unvulcanized second elastic material are prepared. 
     In a next process for extruding the unvulcanized first elastic material and second elastic material, an extrusion device (not illustrated) is used. An extrusion die (not illustrated) of the extrusion device is formed with a first mold cavity having substantially the same design shape as the wiper body  12 , and a second mold cavity having substantially the same design shape as the sliding part  14 , as openings. The extrusion device is configured such that the first elastic material and the second elastic material are individually supplied to the first mold cavity and the second mold cavity, respectively. The unvulcanized first elastic material and second elastic material are concurrently extruded from the extrusion die. 
     The unvulcanized first elastic material and second elastic material pass through the first mold cavity and the second mold cavity of the extrusion die to be extruded from the extrusion die in a state in which the wiper body  12  portion and the sliding part  14  portion are integrated in the joining part  18 . 
     Then, the extruded unvulcanized first elastic material and second elastic material are continuously guided into a vulcanization device (not illustrated), and solidified in the vulcanization device. Thereafter, cutting into a predetermined length is performed, so that the wiper for a machine tool  10 A is obtained. 
     The wiper for a machine tool  10 A configured as described above is mounted on a body part (not illustrated) of the machine tool in a state in which a leading end  16  is in contact with the scraping surface  11 . When the body part moves in the arrow direction in the drawing (thickness direction of the wiper body), the wiper for a machine tool  10 A removes a foreign substance on the scraping surface  11 . 
     In the aforementioned embodiment, it is possible to manufacture the wiper for a machine tool  10 A in which the wiper body  12  made of the first elastic material, and the sliding part  14  made of the second elastic material are integrated by the extrusion molding, and therefore it is possible to eliminate a metal plate conventionally used, resulting in simplification of the manufacturing process. 
     In the aforementioned manufacturing method, the unvulcanized first elastic material and second elastic material are extruded from the die in a state in which the wiper body  12  portion and the sliding part  14  portion are integrated in the joining part  18 , and thereafter the first elastic material and the second elastic material are solidified by vulcanization, so that the wiper for a machine tool  10 A is obtained. The wiper for a machine tool  10 A is thus manufactured, and therefore it is possible to improve precision of the joining part  18  of the wiper body  12  and the sliding part  14 , and reduce dispersion of pressing force and sliding friction. 
     In the wiper for a machine tool  10 A, it is possible to integrate the wiper body  12  and the sliding part  14  without an adhesive in the joining part  18 , and therefore it is possible to eliminate a process for bonding the wiper body  12  and the sliding part  14 . 
     In the wiper for a machine tool  10 A, the joining part  18  has the joint structure, so that it is possible to improve joining strength of the wiper body  12  and the sliding part  14 . In this embodiment, in the joining part  18 , the respective joints formed in the wiper body  12  and the sliding part  14  engage with each other, so that it is possible to further improve the joining strength. 
     In the wiper for a machine tool  10 A, the material for reinforcement and the solid lubricating resin material are added to the leading end portion, so that a coefficient of friction with the scraping surface  11  is reduced, and it is possible to obtain excellent sliding performance and durability performance also in environment in which cutting fluid is not used. 
     A wiper for a machine tool  10 A having a different standard length can be easily manufactured without manufacturing a new member having a different standard by changing the cutting length in the cutting process of the wiper body  12  and the sliding part  14 . 
     (Modification) 
     The present invention is not limited to the aforementioned embodiment, and can be appropriately changed within the spirit of the present invention. 
     Although the case where the sliding part  14  is formed so as to be inclined at the predetermined angle (for example, about 100° to 150°) with respect to the short direction of the wiper body  12  is described in the aforementioned embodiment, the present invention is not limited to this. That is, the wiper for a machine tool may be formed such that the wiper body and the sliding part are joined on the same plane. 
     Although the case where the sliding part  14  is made of the second elastic material obtained by adding the material for reinforcement and the solid lubricating resin material is described in the aforementioned embodiment, the present invention is not limited to this. Only a leading end portion including a leading end of a long side may be made of a second elastic material in which the material for reinforcement and the solid lubricating resin material are added. In this case, in the second mold cavity, the sliding part is formed by supplying a second elastic material including a soft resin material or a rubber material, a material for reinforcement and a solid lubricating resin material to the leading end portion, and supplying a second elastic material made of only a soft resin material or a rubber material not including any material for reinforcement and solid lubricating resin material to other portion except the leading end portion. 
     Although the case where the wiper body  12  and the sliding part  14  are integrated such that the long sides abut on each other is described in the aforementioned embodiment, the present invention is not limited to this. As described in  FIG. 2 , a sliding part  28  may be provided with respective joining parts  30  at one of long sides of a wiper body  26  and the other long side of the wiper body  26  so as to cover a side surface of the wiper body  26 . As illustrated in this figure, the wiper body  26  and the sliding part  28  have a joint structure in which joints  32 ,  34  protruding toward each other are formed in each of the joining parts  30 . Protrusions protruding in the thickness direction are formed in leading ends, so that the joints  32 ,  34  engage with each other. A wiper for a machine tool  10 B according to this modification can be manufactured by extrusion molding, and further has the joint structure, and therefore it is possible to obtain an effect similar to the effect of the aforementioned embodiment. 
     Like a wiper for a machine tool  10 C illustrated in  FIG. 3 , a joining part  36  may have a configuration inversed to the aforementioned embodiment. That is, a joint  40  of a wiper body  33  protrudes from the center in the thickness direction, and is formed in a reversed T-shape. A joint  38  of a sliding part  35  is forked with space at the center in the thickness direction, and a protrusion that protrudes in the thickness direction is formed at a leading end. Thus, the joining part  36  is formed such that the joint  38  and the joint  40  engage with each other. The wiper for a machine tool  10 C according to this modification can be manufactured by extrusion molding, and the joining part  36  further has a joint structure, and therefore it is possible to obtain an effect similar to the effect of the aforementioned embodiment. 
     Furthermore, modifications of the joint structure will be described with reference to  FIGS. 4A, 4B  and  FIGS. 5A to 5D . In a wiper for a machine tool  10 D illustrated in  FIG. 4A , a joint  46  of a wiper body  37  protrudes and inclines from one end to the other end in the thickness direction. A joint  44  of a sliding part  39  inclines from one end toward the other end in the thickness direction in the opposite direction to the joint  46  of the wiper body  37 . Thus, a joining part  42 A is formed such that respective inclined surfaces of the joints  44 ,  46  abut on each other. In a wiper for a machine tool  10 E illustrated in  FIG. 4B , an inclined surface of a joining part  42 B is formed in the opposite direction to the wiper for a machine tool  10 D of  FIG. 4A . 
     In each of the wipers for a machine tool illustrated in  FIG. 5A  to  FIG. 5D , a joint of a wiper body has a protrusion protruding from the center in the thickness direction, a joint of a sliding part has two protrusions, and is formed with a groove recessed at the center in the thickness direction, and the protrusion and the groove are combined to form a joining part. 
     In a wiper for a machine tool  10 F illustrated in  FIG. 5A , a joining part  52  of a wiper body  45  and a sliding part  47  has a substantially V-shape. That is, a joint  56  of the wiper body  45  has a V-shaped protrusion. A joint  54  of the sliding part  47  has two protrusions, and has a V-shaped groove. 
     In a wiper for a machine tool  10 G illustrated in  FIG. 5B , a joining part  58  of a wiper body  49  and a sliding part  51  has a substantially U-shape. That is, a joint  62  of the wiper body  49  has a U-shaped protrusion. A joint  60  of the sliding part  51  has two protrusions, and has a U-shaped groove. 
     In a wiper for a machine tool  10 H illustrated in  FIG. 5C , a joining part  64  of a wiper body  53  and a sliding part  55  has a substantially V-shape with a bottom part. That is, a joint  68  of the wiper body  53  has a protrusion formed in the substantially V-shape with the bottom part. A joint  66  of the sliding part  55  has two protrusions, and has a groove in the substantially V-shape with the bottom part. 
     In a wiper for a machine tool  10 J illustrated in  FIG. 5D , a joining part  70  of a wiper body  57  and a sliding part  59  has a channel shape. That is, a joint  74  of the wiper body  57  has a channel-shaped protrusion. A joint  72  of the sliding part  59  has two protrusions, and has a channel-shaped groove. 
     The wipers for a machine tool  10 D to  10 H,  10 J illustrated in  FIGS. 4A, 4B  and  FIGS. 5A to 5D  can be manufactured by extrusion molding, and furthermore, the joining parts  52 ,  58 ,  64 ,  70  have the respective joint structures, and therefore it is possible to obtain effects similar to the effect of the aforementioned embodiment. 
     REFERENCE SIGNS LIST 
     
         
           10 A to  10 H,  10 J wiper for a machine tool 
           12 ,  26 ,  33 ,  37 ,  41 ,  45 ,  49 ,  53 ,  57  wiper body 
           14 ,  28 ,  35 ,  39 ,  43 ,  47 ,  51 ,  55 ,  59  sliding part 
           18 ,  30 ,  36 ,  42 A,  42 B,  52 ,  58 ,  64 ,  70  joining part 
           20 ,  22 ,  32 ,  34 ,  38 ,  40 ,  44 ,  46 ,  48 ,  50 ,  54 ,  56 ,  60 ,  62 , 
           66 ,  68 ,  72 ,  74  joint