Belt mechanism

Abstract

To provide a belt mechanism capable of making assemblability excellent while having versatility in the belt mechanism in which a tension adjustment mechanism is fitted to a movable body itself.SOLUTION: A belt mechanism 1 includes: a driving pulley 2 driven by a driving source; a rotatably supported driven pulley 3; an endless toothed belt 4 wound around between the driving pulley 2 and the driven pulley 3; a movable body 5 reciprocating between the driving pulley 2 and the driven pulley 3 along a circumferential direction of the toothed belt 4; belt pressing means 61 fitted to the movable body 5, and giving tension to the toothed belt 4 by pressing an outer peripheral surface 4A of the toothed belt 4 so as to make tension of the toothed belt 4 during travel constant; and a tension adjustment mechanism 6 having support means 62 for supporting an inner peripheral surface 4B of the toothed belt 4.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a belt mechanism having a moving body that moves back and forth between a driving pulley and a driven pulley along the circumferential direction of a toothed belt wound between the driving pulley and the driven pulley, and a tension adjustment mechanism for maintaining an appropriate tension in the toothed belt. [Background technology]

[0002] Among belt mechanisms having a drive pulley, a driven pulley, and a toothed belt wound between the drive pulley and the driven pulley, there is a belt mechanism in which a moving body such as a printer carriage print head is attached to the toothed belt so that it can move back and forth between a pair of pulleys, as shown in FIG. 7 of Patent Document 3, and this has been widely used in the past.

[0003] In a belt mechanism having such a moving body, it is necessary to maintain good meshing (positioning) of the toothed belt, so Patent Document 3 discloses an embodiment in which a tension adjustment mechanism is added that can impart tension to the toothed belt and automatically adjust the tension to be constant while the belt is running, as shown in Figure 3.

[0004] Generally, a toothed belt is attached between pulleys (wound around and pulled taut with tension) and in order to automatically adjust the tension of the toothed belt to a constant level (including adjusting for the drop in tension that occurs at the beginning of operation), a tension adjustment mechanism (a combination of a tension pulley, tensioner, shaft moving means, and a spring or other biasing means) is usually used, as shown in (A) and (B) below.

[0005] (A) The tension of a toothed belt is adjusted by applying a spring or other force to a relaxed toothed belt suspended between two or more pulleys and pushing or pulling the toothed belt with a tensioner (tension pulley). (B) With the toothed belt suspended between two or more pulleys in a relaxed state, a spring or other force is applied to move the pulley shaft of at least one of the pulleys, thereby expanding the axial distance between the pulleys and thereby adjusting the tension of the toothed belt.

[0006] However, with such a method, even in a belt mechanism equipped with a movable body that can move back and forth in a predetermined direction, extra space is required outside the pulley layout for adjusting the tension of the toothed belt, which results in the belt mechanism itself becoming larger (for example, see FIG. 3 of Patent Document 3).

[0007] In order to avoid an increase in the size of the belt mechanism, it is conceivable to attach a tension adjustment mechanism to the moving body itself.

[0008] In this regard, Patent Documents 1 and 2 disclose a belt mechanism in which a tension adjustment mechanism is attached to the moving body itself, as shown in the comparison table in Table 1 below.

[0009] [Table 1] [Prior art documents] [Patent documents]

[0010] [Patent Document 1] Japanese Patent Application Publication No. 2-127313 [Patent Document 2] Japanese Utility Model Application Publication No. 59-98152 [Patent Document 3] Japanese Patent Application Publication No. 7-125369 Summary of the Invention [Problem to be solved by the invention]

[0011] However, in the belt mechanisms of Patent Documents 1 and 2 (see, for example, Figures 1 and 2 of Patent Document 1), the tension adjustment mechanism is attached to the moving body itself, which allows the belt mechanism to take up less space and avoids increasing in size. However, in addition to attaching the moving body to one end of the toothed belt, it is necessary to attach the moving body to the other end of the toothed belt via the tension adjustment mechanism, which raises concerns that the ease of assembly of the entire belt mechanism (particularly the pair of pulleys, the toothed belt, the moving body, and the tension adjustment mechanism) may be impaired.

[0012] In addition, since a belt mechanism equipped with a moving body is intended for general industrial use, it is desirable to reconsider the mounting structure of the moving body to the toothed belt, as well as the mounting structure of the tension adjustment mechanism to the moving body, so as to have versatility (relatively simple structure) while also improving ease of assembly.

[0013] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a belt mechanism in which a tension adjustment mechanism is attached to a moving body itself, which has versatility and can be easily assembled. [Means for solving the problem]

[0014] The present invention includes a drive pulley driven by a drive source; A rotatably supported driven pulley; an endless toothed belt wound between the drive pulley and the driven pulley; a moving body that reciprocates between the driving pulley and the driven pulley along a circumferential direction of the toothed belt; The belt mechanism includes a belt pressing means attached to the moving body for pressing one side of the toothed belt to apply tension to the toothed belt so that the tension of the toothed belt is constant while the toothed belt is moving, and a tension adjustment mechanism having a support means for supporting the other side of the toothed belt.

[0015] According to the above configuration, the tension adjustment mechanism attached to the moving body itself is fixed to the endless toothed belt in a manner in which the toothed belt is clamped between a belt pressing means that presses one side of the toothed belt to apply tension to the toothed belt and a support means that supports the other side of the toothed belt. In other words, the pressing function of the belt pressing means, which presses one side of the toothed belt to apply tension to the toothed belt and adjusts the applied tension so that it is constant during running, can also serve as a fixing function for fixing the moving body to the toothed belt. In other words, the tension adjustment mechanism itself has the function of attaching the moving body to the toothed belt. Therefore, as in Patent Documents 1 and 2, a tension adjustment mechanism is attached to the moving body itself, ensuring space saving, but compared to a belt mechanism in which a toothed belt is formed with ends, one end of which is directly connected to the moving body and the other end is connected to the moving body via a tension adjustment mechanism, there is no need to connect the toothed belt (one end of the belt) to the moving body via a fixing means separate from the tension adjustment mechanism (such as a fixing device for the end of the belt), and therefore the belt mechanism can be made versatile and easy to assemble. The drive pulley may be driven by a drive source to be able to rotate in both forward and reverse directions.

[0016] Further, the present invention provides the above-mentioned belt mechanism, wherein the belt pressing means is a first engagement portion provided slidably along a thickness direction of the toothed belt and having a belt pressing portion that contacts an outer circumferential surface of the toothed belt; a spring that is tensioned along a thickness direction of the toothed belt and biases the belt pressing portion in a direction to press the belt pressing portion against an outer circumferential surface side of the toothed belt; a holder that accommodates the spring in a state in which the belt pressing portion is slidable; The support means is a pair of second engagement portions fixed to the holder and contacting an inner circumferential surface of the toothed belt at at least two points; The pair of second engagement portions may be disposed spaced apart from each other on both sides of the first engagement portion along a circumferential direction of the toothed belt.

[0017] According to the above configuration, the tension adjustment mechanism to which the movable body is attached is fixed to the toothed belt in a manner such that the toothed belt is tensioned in a V-shape or an inverted V-shape by the first engagement portion having a belt pressing portion that contacts the outer peripheral surface of the toothed belt due to the biasing action of the spring, and a pair of second engagement portions that contact the inner peripheral surface of the toothed belt and are arranged on both sides of the first engagement portion and spaced apart from each other along the circumferential direction of the toothed belt. Therefore, while the moving body is stably fixed to the endless toothed belt, tension can be applied to the toothed belt, and the tension of the toothed belt can be automatically adjusted to be constant while it is running.

[0018] Also, the present invention may be characterized in that the belt mechanism further comprises a reverse return prevention means for preventing the belt pressing portion from sliding in a direction opposite to the biasing direction of the spring.

[0019] According to the above configuration, when the tension of the toothed belt weakens and the belt pressing portion slides toward the outer peripheral surface of the toothed belt due to the force of the spring, the sliding belt pressing portion can be prevented from returning. This makes it possible to stably fix the moving body by the endless toothed belt, while applying tension to the toothed belt and automatically adjusting the tension of the toothed belt so that it remains constant while it is running.

[0020] Further, the present invention provides the above-mentioned belt mechanism, The first engagement portion is a belt holding portion that contacts an inner peripheral surface of the toothed belt and fixes a positional relationship of the moving body with respect to the toothed belt in a direction parallel to a pulley center line that connects a rotation center of the drive pulley and a rotation center of the driven pulley, and a connecting portion that connects the belt pressing portion and the belt holding portion, The belt holding portion may be characterized in that it faces the belt pressing portion across the toothed belt, and both side surfaces are formed so as to be able to come into contact with tooth portions of the toothed belt adjacent to each other in the circumferential direction of the toothed belt.

[0021] According to the above configuration, in the tension adjustment mechanism, compared to a case where a belt holding portion is not formed (a case where the first engagement portion is formed only by a belt pressing portion), it is possible to more reliably position the moving body relative to the toothed belt in a direction parallel to the pulley center line, and it is possible to specifically realize a configuration in which the tension of the toothed belt can be adjusted in a more stable and reliable manner, even if the pulley layout is arranged so that the moving body moves back and forth in the vertical (gravity) direction, for example. Effect of the Invention

[0022] It is possible to provide a belt mechanism in which a tension adjustment mechanism is attached to a moving body itself, which has versatility and excellent assembly properties. [Brief description of the drawings]

[0023] [Figure 1] FIG. 2 is a front view of the belt mechanism of the embodiment. [Diagram 2] FIG. 2 is a schematic top view of the belt mechanism of the embodiment. [Diagram 3] FIG. 3 is a cross-sectional view taken along line A-A of FIG. 2. [Figure 4] FIG. 3 is a cross-sectional view taken along line B-B of FIG. [Diagram 5] FIG. 2 is a cross-sectional perspective view of the toothed belt according to the embodiment. [Figure 6] 5A to 5C are explanatory diagrams relating to the assembly of the belt mechanism of the embodiment. [Figure 7] 5A to 5C are explanatory diagrams relating to the assembly of the belt mechanism of the embodiment. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] (Embodiment) This embodiment is an example of the application of the present invention to a belt mechanism 1 (e.g., an air conditioner cleaning unit) that is incorporated into devices and equipment that are commonly used in general industrial applications, and that has a moving body 5 that moves back and forth a predetermined distance between a driving pulley 2 and a driven pulley 3 via a toothed belt 4, and in which a tension adjustment mechanism 6 is added to the moving body 5 itself for automatically keeping the tension of the toothed belt 4 constant.

[0025] (Belt mechanism 1) As shown in Figures 1 and 3, the belt mechanism 1 includes a drive pulley 2 that is driven by a drive source (not shown) to rotate in both forward and reverse directions, a driven pulley 3 that is supported to rotate freely, an endless toothed belt 4 that is wound between the drive pulley 2 and the driven pulley 3, a moving body 5 that moves back and forth between the drive pulley 2 and the driven pulley 3 along the circumferential direction of the toothed belt 4, and a tension adjustment mechanism 6 that is attached to the moving body 5 and has a belt pressing means 61 that presses an outer peripheral surface 4A (one side) of the toothed belt 4 to apply tension to the toothed belt 4 so that the tension of the toothed belt 4 is constant while it is running, and a support means 62 that supports the inner peripheral surface 4B (the other side) of the toothed belt 4.

[0026] In the description of the belt mechanism 1, for convenience, in Fig. 1 to Fig. 5, a direction parallel to a pulley center line PCL connecting the central axis 21 of the driving pulley 2 and the central axis 31 of the driven pulley 3 is defined as a left-right direction or horizontal direction, and a direction perpendicular to the pulley center line PCL and parallel to the radial direction of the driving pulley 2 (driven pulley 3) (thickness direction of the toothed belt 4) is defined as a top-bottom direction. In Fig. 1 and Fig. 3, the left side is the other side and the right side is the one side. In Fig. 1 and Fig. 3, the front side of the paper in the belt width direction is defined as the front, the back side of the paper is defined as the rear, and in Fig. 2, the side of a base body 64 described later in the belt width direction is defined as the rear, and the side of a holder 613 is defined as the front.

[0027] (Pulley layout) As shown in FIG. 1, the pulley layout of the belt mechanism 1 of this embodiment is configured with a pair of pulleys (a driving pulley 2 and a driven pulley 3). The present invention may be applied to a pulley layout having three or more pulleys, so long as the movable body 5 is configured to be able to reciprocate in a predetermined direction via the toothed belt 4.

[0028] The driving pulley 2 and the driven pulley 3 are toothed pulleys. Groove portions (not shown) having a shape corresponding to the tooth shape of the tooth portion 44 of the toothed belt 4 (for example, a tooth shape generally called straight teeth) are formed on the outer periphery of the driving pulley 2 and the driven pulley 3. In this embodiment, the groove portions formed on the outer periphery of the driving pulley 2 and the driven pulley 3 have a shape corresponding to the straight teeth of the tooth portion 44 and extend along the axial direction.

[0029] The center distance between the driving pulley 2 and the driven pulley 3 is fixed and unadjustable, and is, for example, about 200 mm to 600 mm (430 mm in this embodiment). The drive pulley 2 is connected to a drive source (eg, a servo motor) via a central shaft 21 (drive shaft), and is driven by the drive source to be able to rotate forward and backward. The driven pulley 3 is rotatably supported by a central shaft 31 (driven shaft). Since the main purpose of the belt mechanism 1 of this embodiment is to move the moving body 5 back and forth via the toothed belt 4, rather than to transmit power via the toothed belt 4 (such as a reduction mechanism), the diameter of the driving pulley 2 and the diameter of the driven pulley 3 may be the same, and the speed ratio between the pulleys (diameter of the driven pulley 3 / diameter of the driving pulley 2) is set to, for example, about 1 (also in this embodiment).

[0030] (Toothed belt 4) As shown in Fig. 1, the toothed belt 4 is an endless meshing power transmission belt, and as shown in the partial cross-sectional perspective view of Fig. 5, the toothed belt 4 includes a back portion 43 in which a core wire 42 extending in the belt longitudinal direction (belt circumferential direction) is embedded, and a plurality of teeth 44 provided at predetermined intervals on the inner peripheral surface of the back portion 43 and extending in the belt width direction, and the belt surface (inner peripheral surface 4B) on the toothed portion 44 side is composed of a tooth cloth 45. The back portion 43 has a back rubber layer disposed on the outer peripheral surface 4A side of the core wire 42 of the toothed belt 4, and this back rubber layer forms the outer peripheral surface 4A of the toothed belt 4. Furthermore, a toothed rubber layer is provided between the tooth cloth 45 and the core wire 42 on the inner peripheral surface side of the belt of the core wire 42. Between adjacent tooth portions 44, flat tooth bottom portions 46 are present, and the tooth portions 44 and the tooth bottom portions 46 are alternately formed along the belt longitudinal direction. That is, the surface of the tooth portions 44 and the inner peripheral surface of the back portion 43 (i.e., the surface of the tooth bottom portions 46) are formed of a single continuous tooth cloth 45. In the embodiment of Fig. 5, the other surface on the side where the tooth portions 44 are not formed (the outer peripheral surface 4A of the toothed belt 4) is not covered with a fabric (woven fabric, knitted fabric, nonwoven fabric, etc.), but may be covered as necessary. In the present application, the tooth cloth 45 constituting the surface of the tooth portion 44 is a constituent element of the tooth portion 44, while the tooth cloth 45 constituting the surface of the tooth bottom portion 46 is a constituent element of the back portion 43. Each tooth cloth constituting the tooth portion 44 is a part of the continuous tooth cloth 45 (a part of the tooth cloth 45 in FIG. 5).

[0031] In this example, the tooth portion 44 has a substantially semicircular cross section in the belt longitudinal direction. The surface of the tooth portion 44 having a substantially semicircular cross section in the belt longitudinal direction is made of a tooth cloth 45, and is formed of a tooth rubber layer formed along the tooth cloth 45. Also in the tooth bottom portion 46, a tooth rubber layer is interposed between the tooth cloth 45 and the core wire 42 (not shown). The thickness of the tooth rubber layer in the tooth bottom portion 46 is extremely thin compared to the thickness of the tooth rubber layer in the tooth portion 44. From the viewpoint of repeatedly ensuring positioning accuracy during operation involving forward and reverse rotation (ensuring synchronous transmission), the average distance between the centers of adjacent tooth portions 44 in the belt longitudinal direction (tooth pitch Pt, see FIG. 5) should be a relatively small value, for example, about 2 mm to 5 mm (3 mm in this embodiment). The value of the tooth pitch Pt also corresponds to the size of the scale of the tooth portions 44 (the length of the tooth portions 44 in the belt longitudinal direction and the tooth height Ht of the tooth portions 44). In other words, the larger the tooth pitch Pt, the larger the scale of the tooth portions 44 becomes.

[0032] The length (circumferential length) of the toothed belt 4 in the belt longitudinal direction (belt circumferential direction) is, for example, about 400 mm to 1400 mm (about 1000 mm in this embodiment). The circumferential length of the toothed belt 4 is determined taking into consideration the manner in which, after the toothed belt 4 is attached between the driving pulley 2 and the driven pulley 3, the tension adjustment mechanism 6 causes the outer peripheral surface 4A of the toothed belt 4 to come into contact with the belt pressing portion 611A of the first engagement portion 611, and the inner peripheral surface 4B of the toothed belt 4 to come into contact with a pair of second engagement portions 621 and 622 on both sides, thereby tensioning the toothed belt 4 in a V-shape when viewed from the front (so that a predetermined belt tension is obtained). The length (width) of the toothed belt 4 in the belt width direction is, for example, about 4 mm to 35 mm (10 mm in this embodiment).

[0033] (Back portion 43 and teeth portion 44) The back rubber layer in the back portion 43 of the toothed belt 4 and the tooth rubber layer in the tooth portion 44 of the toothed belt 4 are composed of a crosslinked rubber composition containing a rubber component. Examples of the rubber component of this crosslinked rubber composition include diene rubber [natural rubber (NR), isoprene rubber (IR), butadiene rubber (BR), chloroprene rubber (CR), butyl rubber (IIR), styrene-butadiene rubber (SBR), vinylpyridine-styrene-butadiene rubber, acrylonitrile-butadiene rubber (nitrile rubber: NBR), acrylonitrile-chloroprene rubber, hydrogenated nitrile rubber (HNBR), etc.], ethylene-α-olefin elastomer (ethylene-propylene copolymer (EPM), ethylene-propylene-diene terpolymer (EPDM), etc.), chlorosulfonated polyethylene rubber (CSM), alkylated chlorosulfonated polyethylene rubber (ACSM), epichlorohydrin rubber, acrylic rubber, silicone rubber, urethane rubber, and fluororubber. These rubber components can be used alone or in combination of two or more. The rubber component of the crosslinked rubber composition constituting the back portion 43 and the teeth portion 44 is preferably chloroprene rubber, particularly from the viewpoint of low cost (chloroprene rubber is also used in this embodiment). The crosslinked rubber compositions constituting the teeth portion 44 and the back portion 43 may be the same crosslinked rubber composition or different crosslinked rubber compositions. The crosslinked rubber composition constituting the back portion 43 and the teeth portion 44 may contain various conventional additives (or compounding agents) as necessary. From the viewpoint of ensuring the power transmission performance (particularly tooth skipping resistance) of the toothed belt 4, the rubber hardness Hs of the crosslinked rubber composition (tooth rubber layer) constituting the teeth portion 44 is preferably about 73 to 83 degrees in type A hardness. In the present application, the type A hardness can be measured using a type A durometer in accordance with the spring type durometer hardness test specified in JIS K6253 (2012).

[0034] (Tooth shape of tooth portion 44) The tooth shape of the toothed portion 44 of the toothed belt 4 may be a tooth shape generally called straight teeth or a tooth shape called helical teeth (teeth with an oblique contact angle on the tooth surface) as long as synchronous transmission (meshing transmission) is possible. The toothed belt 4 used in the belt mechanism 1 of this embodiment has straight teeth.

[0035] The tooth shape belonging to the straight teeth can be selected from the known tooth shapes listed below, as well as modified or special shapes thereof, as appropriate, so as to suit the application of the belt mechanism 1. For example, there is an H-tooth shape having a substantially semicircular cross section, a T-tooth shape having a trapezoidal cross section, and an S-tooth shape (STPD type) having two outwardly bulging convex curved surfaces (arcuate surfaces) connected by a flat surface. From the viewpoint of ensuring the power transmission performance (particularly the transmission capacity and tooth skipping resistance) of the toothed belt 4, it is better to increase the rigidity of the tooth portion 44, and therefore an H-tooth shape (a substantially semicircular cross section) is preferable (the present embodiment also has an H-tooth shape).

[0036] (Core wire 42) In the back portion 43, a core wire 42 extending along the belt longitudinal direction is embedded on the inner peripheral side of the crosslinked rubber composition (back rubber layer) constituting the back portion 43. This core wire 42 acts as a tension member and can improve the running stability and strength of the toothed belt 4. Furthermore, in the back portion 43, the core wire 42, which is a twisted cord extending along the belt longitudinal direction, is usually embedded at a predetermined interval in the belt width direction, and although a plurality of core wires 42 parallel to the belt longitudinal direction may be arranged, from the viewpoint of productivity, it is usually embedded in a spiral shape. When arranged in a spiral shape, the angle of the core wire 42 with respect to the belt longitudinal direction may be, for example, 5° or less, and from the viewpoint of belt running properties, the closer to 0° the more preferable. More specifically, the core wires 42 may be embedded at a predetermined interval (or pitch) (or at equal intervals) from one end to the other end in the belt width direction of the back portion 43, as shown in Fig. 5. The interval (spinning pitch), which is the distance between the centers of adjacent core wires 42, may be larger than the core wire diameter.

[0037] The core wire 42 may be formed of a twisted cord made by twisting together a plurality of strands or multifilament yarns. Of these, a twisted cord of strands is preferred, and one strand may be formed by bundling filaments (long fibers). There are no particular limitations on the thickness of the filaments forming the twisted cord, the number of filaments bundled together, the number of strands, and the twisting configuration. The fibers forming the core wire 42 are not particularly limited, and examples thereof include synthetic fibers such as polyester fibers (polyalkylene arylate fibers, polyparaphenylene naphthalate fibers), polybenzoxazole fibers, acrylic fibers, and polyamide fibers (aliphatic polyamide fibers, aramid fibers, etc.), and inorganic fibers such as glass fibers, carbon fibers, and metal fibers (steel fibers). These fibers can be used alone or in combination of two or more. As the fibers forming the core wire 42, synthetic fibers such as polyester fibers and polyamide fibers, and inorganic fibers such as glass fibers (alkali-free glass fibers, high-strength glass fibers), and carbon fibers are commonly used in terms of low elongation and high strength. From the viewpoint of low cost, alkali-free glass fiber (E glass fiber) is more preferable. The diameter of the core wire 42 is preferably small from the viewpoint of improving the flexibility of the toothed belt 4 (the flexibility of the toothed belt 4 when the toothed belt 4 is wound around the driving pulley 2 and the driven pulley 3), that is, from the viewpoint of suppressing the speed unevenness of the toothed belt 4 due to the up and down movement of the belt pitch line and ensuring high positioning accuracy. The diameter of the core wire 42 is, for example, about 0.15 mm to 0.60 mm (in this embodiment, the type of the core wire is E glass fiber and the diameter of the core wire is 0.35 mm).

[0038] High-strength glass fibers include those with a tensile strength of 300 kg / cm 2 Among the above, glass fibers having the composition shown in Table 1, which have a higher Si content than alkali-free glass fibers (E glass fibers), can be preferably used. For comparison, the composition of E glass fiber is also shown in Table 2. Examples of such high-strength glass fibers include K glass fiber, U glass fiber (both manufactured by Nippon Glass Fiber Co., Ltd.), T glass fiber (manufactured by Nitto Boseki Co., Ltd.), R glass fiber (manufactured by Vetrotex), S glass fiber, S-2 glass fiber, and ZENTRON glass fiber (all manufactured by Owens Corning Fiberglass Co., Ltd.).

[0039] [Table 2]

[0040] In particular, in applications where a high load is applied, multifilament carbon fiber yarn is preferably used. For example, the carbon fiber manufactured by Toray Industries, Inc. under the trade name "TORAYCA" is used.

[0041] The twisted cord used as the core wire 42 may be subjected to an adhesive treatment in order to enhance adhesion with a crosslinked rubber composition forming a back rubber layer (forming the outer peripheral surface 4A of the toothed belt 4 on the outer peripheral surface side of the back portion 43). The adhesive treatment may be, for example, a method of immersing the twisted cord in a resorcin-formalin-latex treatment liquid (RFL treatment liquid) and then heating and drying to form a uniform adhesive layer on the surface of the twisted cord. The RFL treatment liquid is a mixture of a precondensate of resorcin and formalin mixed with latex, and the latex may be, for example, chloroprene, styrene-butadiene-vinylpyridine terpolymer (VP latex), nitrile rubber, hydrogenated nitrile rubber, or the like. Furthermore, the adhesive treatment may be a method of treating the twisted cord with the RFL treatment liquid after performing a pretreatment with an epoxy compound or an isocyanate compound.

[0042] (Toothcloth 45) The tooth cloth 45 constituting the inner peripheral surface 4B (surfaces of the tooth portion 44 and the tooth bottom portion 46) of the toothed belt 4 may be formed of a fabric such as a woven fabric, a knitted fabric, or a nonwoven fabric. Conventionally, it is often a woven fabric (canvas), and is composed of a fabric woven with warp threads extending in the belt width direction and weft threads extending in the belt longitudinal direction. The weave structure of the woven fabric is not particularly limited as long as the warp threads and weft threads are regularly crossed in the vertical and horizontal directions, and may be any of plain weave, twill weave (or twill weave), satin weave (satin weave), etc., or a combination of these weaves. Preferred woven fabrics have twill and satin weave structures. As the fibers forming the weft and warp of the tooth cloth 45, organic fibers are generally used, and examples thereof include cellulose-based fibers such as cotton and rayon, polyester-based fibers (PET fibers, etc.), polyamide-based fibers (aliphatic polyamide fibers such as polyamide 66 fibers, aramid fibers, etc.), PBO fibers, and fluororesin fibers (polytetrafluoroethylene (PTFE) fibers, etc.). These fibers can be used alone or in combination of two or more. Also preferred are composite yarns of these fibers and elastic yarns having elasticity (for example, polyurethane-based elastic yarns having elasticity such as spandex formed from polyurethane, and processed yarns that have been stretched (for example, woolly processing, shrink processing, etc.)). The form of the warp and weft yarns is not particularly limited, and may be a monofilament yarn, which is a single long fiber, a multifilament yarn, which is made by arranging or twisting filaments (long fibers), or a spun yarn, which is made by twisting short fibers. The multifilament yarn or spun yarn may be a mixed twisted yarn or a mixed spun yarn using multiple types of fibers. The weft yarn preferably contains an elastic yarn having elasticity, and in terms of weaving properties, the warp yarn usually does not contain an elastic yarn in many cases. In order to ensure the elasticity of the tooth cloth 45 in the belt longitudinal direction, the weft yarn containing the elastic yarn extends in the belt longitudinal direction, and the warp yarn extends in the belt width direction. In order to improve the adhesion with the tooth rubber layer, the fabric forming the tooth cloth 45 may be subjected to an adhesive treatment. Examples of the adhesive treatment include a method of immersing the fabric in an RFL treatment liquid and then heating and drying; a method of treating with an epoxy compound or an isocyanate compound; a method of dissolving a rubber composition in an organic solvent to make a rubber paste, immersing the fabric in the rubber paste and then heating and drying; and a method combining these treatment methods. These methods can be performed alone or in combination, and the order of treatment and the number of treatments are not limited. For example, the fabric may be pretreated with an epoxy compound or an isocyanate compound, further immersed in an RFL treatment liquid, and then heated and dried. The fabric subjected to the above adhesive treatment is referred to as a tooth cloth precursor.

[0043] (Manufacturing method of toothed belt 4) The toothed belt 4 according to the present embodiment may be produced by a normal method, for example, the following method (press-in method). First, a tooth cloth precursor for forming the tooth cloth 45, and uncrosslinked rubber sheets for forming the tooth rubber layer and the back rubber layer are produced. In this method (press-in method), the same rubber composition is used for the rubber composition constituting the tooth rubber layer and the back rubber layer.

[0044] Next, a tooth cloth precursor for forming the tooth cloth 45 is wound around the outer circumferential surface of a cylindrical mold having a plurality of grooves (recesses) corresponding to the teeth 44 of the toothed belt 4. Then, a twisted cord constituting the core wire 42 is wound helically at a predetermined pitch (so as to have a predetermined pitch in the axial direction of the cylindrical mold) around the outer circumferential surface of the wound tooth cloth precursor. Furthermore, an uncrosslinked rubber sheet for forming the tooth rubber layer and the back rubber layer is wound around the outer circumferential side to form an uncrosslinked belt molding (uncrosslinked laminate).

[0045] Next, the uncrosslinked belt molded body is placed on the outer periphery of the cylindrical mold, and a rubber jacket, which is a steam barrier material, is placed on the outside of the uncrosslinked belt molded body. Next, the jacketed belt molded body and the cylindrical mold are placed inside a crosslinking molding device such as a vulcanizing can. When the belt molded body is heated and pressurized inside the crosslinking molding device, the rubber composition of the uncrosslinked rubber sheet and the tooth cloth precursor are pressed into the grooves (concave strips) of the cylindrical mold to form a tooth portion of a desired shape, and the rubber composition of the uncrosslinked rubber sheet is crosslinked, and each component is bonded and hardened integrally by the crosslinking reaction of the uncrosslinked rubber component contained in the belt molded body, forming a sleeve-shaped crosslinked molded body (crosslinked belt sleeve). At this time, the tooth cloth precursor is stretched to a shape that follows the contour shape of the tooth portion 44, and becomes the tooth cloth 45 placed on the surface of the tooth portion 44 and the surface of the back portion 43 on the tooth portion 44 side (surface of the tooth bottom portion 46).

[0046] Finally, the cross-linked belt sleeve is removed from the cylindrical mold and cut to a predetermined width, thereby obtaining a plurality of toothed belts 4.

[0047] (Mobile unit 5) As shown in FIG. 1, the movable body 5 is attached to the toothed belt 4 via a tension adjustment mechanism 6 described later so that it can move back and forth between a pair of pulleys (between a driving pulley 2 and a driven pulley 3) via the toothed belt 4 in a predetermined direction (a direction parallel to the pulley center line PCL).

[0048] The moving body 5 is formed to have a predetermined shape and size according to the application (purpose of reciprocating movement) of the belt mechanism 1 and the user's request (design of the device equipped with the belt mechanism 1). Since the shape and the like are arbitrary, in this embodiment, as shown in Figs. 1 to 5, the moving body 5 is illustrated to have a substantially rectangular parallelepiped shape.

[0049] (Tension adjustment mechanism 6) The tension adjustment mechanism 6 is attached to the moving body 5 as shown in FIG. The tension adjusting mechanism 6 is formed so as to also serve as a means for fixing the moving body 5 to the toothed belt 4. Therefore, the belt pressing means 61 (first engagement portion 611, spring 612, holder 613), support means 62 (arm portion 623 having a pair of second engagement portions 621, 622), and reverse prevention means 63 (ratchet mechanism portion), described below, are formed as a single unit (one assembly).

[0050] (Belt pressing means 61) As shown in FIG. 3, the belt pressing means 61 has a first engagement portion 611, a spring 612, and a holder 613.

[0051] (First engagement portion 611) The first engagement portion 611 is provided slidably within the holder 613 along the belt thickness direction of the toothed belt 4. As shown in FIG. 4, the tip portion (lower side) of the first engagement portion 611 is formed into a U-shaped cross section by a belt pressing portion 611A and a belt holding portion 611B that engage with the toothed belt 4, and a connecting portion 611C that connects the belt pressing portion 611A and the belt holding portion 611B (behind the toothed belt 4). A spring 612 comes into contact with an upper surface 611D (upper side) of the first engagement portion 611 opposite to the tip portion. The belt pressing portion 611A comes into contact with the outer circumferential surface 4A of the toothed belt 4 by the biasing force of the spring 612, as shown in FIGS. The belt holding portion 611B is positioned opposite the belt pressing portion 611A across the toothed belt 4 so as to fix the positional relationship of the moving body 5 with respect to the toothed belt 4 in a direction parallel to the pulley center line PCL (horizontal direction), and both side surfaces of the belt holding portion 611B are formed so as to be able to come into contact with two adjacent tooth portions 44 in the belt longitudinal direction on the inner surface 4B of the toothed belt 4 (see Figure 3).

[0052] (Spring 612) The spring 612 is a compression spring that is stretched in the belt thickness direction of the toothed belt 4 within the holder 613 and biases the first engagement portion 611 (belt pressing portion 611A) in a direction pressing the first engagement portion 611 against the outer circumferential surface 4A of the toothed belt 4. The spring 612 is attached in a compressed state in a direction shorter than its natural length (a state in which the self-elastic recovery force acts in the stretching direction), and is stretched between the inner bottom surface 613A of the holder 613 and the upper surface 611D of the first engagement portion 611 along the belt thickness direction (up and down direction) so that the first engagement portion 611 (belt pressing portion 611A) is used in a state in which it contacts the outer circumferential surface 4A (back surface) of the toothed belt 4.

[0053] The spring 612 is preferably a coil spring so that predetermined spring characteristics can be repeatedly obtained corresponding to a predetermined belt tension for each belt mechanism 1 (particularly for each level of belt tension), and a coil spring is also used in this embodiment. In addition, when the toothed belt 4 equipped with the moving body 5 is used for general industrial purposes, the belt tension when stationary (the belt tension when the drive pulley 2 is stopped) may be at a level that does not cause the toothed belt 4 to slacken, for example, about 1 N / 1 mm belt width (this embodiment is also 1 N / 1 mm belt width).

[0054] The spring wire of the spring 612 is preferably an oil-tempered wire for springs having a circular cross-section, etc., conforming to JIS G3560:1994, and this embodiment employs an oil-tempered wire for springs having a circular cross-section conforming to the above standard. The diameter of the spring wire, as well as the winding diameter and winding length (natural length) of the spring 612 are also designed and determined so that predetermined spring characteristics are repeatedly obtained for each belt mechanism 1 (particularly for each level of belt tension).

[0055] (Holder 613) The holder 613 is a storage case having an opening at the bottom, which stores the first engagement portion 611 and the spring 612. The rear surface of the holder 613 is fixed to the base body 64.

[0056] (Anti-reverse means 63) In this embodiment, as shown in Fig. 4, a known ratchet mechanism is used as the reverse-back prevention means 63 that prevents the first engagement portion 611 (belt pressing portion 611A) from sliding (reverse) in the direction opposite to the biasing direction of the spring 612 (upward in Fig. 4). However, the present invention is not limited to this, and the reverse-back prevention means 63 may be, for example, a known one-way clutch mechanism.

[0057] The ratchet mechanism serving as the reverse return prevention means 63 is configured so that a ratchet pawl 631 formed behind the first engagement portion 611 can engage with ratchet teeth 632 provided at a position facing the ratchet pawl 631. The ratchet pawl 631 and the ratchet teeth 632 face each other in the front-rear direction.

[0058] As shown in FIG. 4, the ratchet pawl 631 is formed integrally with the first engagement portion 611 and is a pawl that partially protrudes rearward and diagonally upward from the rear surface of the first engagement portion 611 (at an angle of approximately 30° from the rear surface) in a slightly tapered shape, and extends to a position where it engages with ratchet teeth 632 formed on the rear base body 64. As the first engagement portion 611 is pushed down by the biasing action of the spring 612 to the extent that the toothed belt 4 is loosened, the ratchet pawl 631 is formed so that when it climbs over a number of ratchet teeth 632 described below, the tip portion elastically deforms into a bow shape in the direction approaching the main body of the first engagement portion 611, and immediately after climbing over the plurality of ratchet teeth 632, the tip portion elastically recovers in the direction away from the main body of the first engagement portion 611, so that it can engage with the ratchet teeth 632 without being able to return to its original position.

[0059] A plurality of ratchet teeth 632 (five in this embodiment) are formed at a predetermined pitch along the vertical direction on the front portion of the base body 64. The ratchet teeth 632 are formed in a positional relationship that allows them to engage with the ratchet pawl 631 within the actual movable range of the first engagement portion 611 (the vertical sliding range from when the toothed belt 4 is attached to when the toothed belt 4 becomes loose during running). The pitch of the ratchet teeth 632 depends on the strength (rigidity) of the ratchet teeth 632 and the engagement force with the ratchet pawl 631, but it is preferable to set it as small as possible so that the tension can be adjusted in more steps.

[0060] At the lower ends of the multiple ratchet teeth 632, a step portion 633 (a protruding portion extending further forward than the tips of the multiple ratchet teeth 632) is formed which acts as a stopper to prevent the first engagement portion 611 from falling off the holder 613.

[0061] (Support means 62) 3 and 4, the support means 62 is composed of a pair of second engagement portions 621 and 622, and an arm portion 623 connecting the second engagement portions 621 and 622, and is formed integrally with the base body 64 at a lower portion of the base body 64. Therefore, the support means 62 is fixed to the holder 613 via the base body 64. The pair of second engagement portions 621 and 622 are arranged apart from each other on either side of the first engagement portion 611 in the horizontal direction along the belt longitudinal direction of the toothed belt 4, and contact the inner surface 4B of the toothed belt 4 at two points. In other words, the support means 62 is configured to support the toothed belt 4 on both sides of the first engagement portion 611 from the inner circumferential surface 4B side.

[0062] The support means 62 may be formed separately (separately from the base body 64) and connected (fastened) integrally to the base body 64 when the tension adjustment mechanism 6 is assembled. Specifically, the support means 62 comprises a portion extending horizontally on both sides (one side and the other side) at the bottom of the base body 64, a portion extending downward from each of the left and right ends, and a portion extending forward from each of the lower ends (leading edge portions), and these pair of leading edge portions are configured to form a pair of second engagement portions 621, 622 that contact the inner surface 4B of the toothed belt 4.

[0063] The distance (interval) between the first engagement portion 611 and the pair of second engagement portions 621-622 along the direction parallel to the pulley center line PCL may be equal or different on the left and right, but from the viewpoint of preventing distortion of the posture of the movable body 5 with respect to the pulley layout, it is preferable to set the distance equal on the left and right. In this embodiment, the distance is equal on the left and right. This distance is arbitrary as long as the toothed belt 4 is stretched in a V-shape when viewed from the front between a pair of second engagement portions 621 and 622 on either side of the first engagement portion 611, the tension adjustment mechanism 6 also serves as a means for fixing the moving body 5 to the toothed belt 4, and a predetermined tension can be applied to the toothed belt 4, but is set taking into consideration the level of belt tension, the rigidity (flexibility) of the toothed belt 4, the state of the assembly of the moving body 5 and the tension adjustment mechanism 6, etc.

[0064] (Manufacture of tension adjustment mechanism 6) When the ratchet pawl 631 is molded integrally with the main body of the first engagement portion 611 as in this embodiment, it is preferable to form the first engagement portion 611 into a predetermined shape by injection molding using a synthetic resin material (e.g., a thermoplastic resin such as polypropylene resin or polyacetal resin) that combines the properties of both an elastic material and a sliding material. In addition, when the ratchet pawl 631 is a separate part from the main body of the first engagement portion 611, for example, the first engagement portion 611 may be formed from a metal material (such as an aluminum alloy casting) and the ratchet pawl 631 may be formed as a single part from the above-mentioned synthetic resin material, and the first engagement portion 611 may be formed in such a manner that the ratchet pawl 631 is connected (inserted) into the main body of the first engagement portion 611.

[0065] The holder 613 and the base body 64 may be formed by injection molding using a synthetic resin material having the properties of a sliding material (low friction material). Alternatively, the sliding material (low friction material) may be a base material made of a metal material such as steel, brass, bronze, etc., finished into a predetermined shape by a cutting method or the like, and the sliding surface may be formed of a synthetic resin material having surface properties with a lower friction coefficient than the base material. The synthetic resin material preferably has self-lubricating properties. Specifically, the synthetic resin as the main component is preferably a thermoplastic resin such as polyamide, polyacetal, polytetrafluoroethylene, polyphenylene sulfide, ultra-high molecular weight polyethylene, or a thermosetting resin such as phenol. These synthetic resins as the main component may or may not contain a solid lubricant such as molybdenum disulfide, tungsten disulfide, graphite, or boron nitride. These synthetic resins as the main component may or may not contain a reinforcing fiber. In addition, when the substrate is made of a metal material, the sliding surface may be coated with the solid lubricant as long as it has a surface characteristic with a lower friction coefficient than the substrate, or the sliding surface may be plated with a lubricating agent.

[0066] (Assembly of tension adjustment mechanism 6) To assemble the belt pressing means 61, first, the spring 612 and the first engagement part 611 are inserted all the way into the holder 613. At this time, in order to improve the ease of assembly of the belt mechanism 1 (particularly the ease of work when tensioning the toothed belt 4 after it is attached between the pulleys), it is preferable to temporarily fix the first engagement part 611 in a state where it is inserted all the way into the holder 613 (a state where the spring 612 is compressed more than in actual use). As a method of this temporary fixing, for example, it is preferable to form a hole penetrating horizontally in the first engagement part 611 and the holder 613 in advance with the first engagement part 611 inserted all the way into the holder 613, and in this state, to penetrate (skewer) the holder 613 including the first engagement part 611 from one side in the horizontal direction to the other side. Details will be described in the section "Assembling the belt mechanism 1" below.

[0067] Next, to assemble the anti-reverse means 63 (ratchet mechanism), as shown in Figures 2 and 3, the holder 613 and base body 64 are fixed together via rivets 613D and 613E in such a manner that a pair of through holes extending in the front-rear direction provided in the left and right rear flanges 613B and 613C of the holder 613 coincide with a pair of through holes extending in the front-rear direction provided in the base body 64. In the case where the support means 62 is formed as a part of the base body 64 as in this embodiment, the tension adjustment mechanism 6 is completed by the above assembly.

[0068] (Attachment structure of tension adjustment mechanism 6 to moving body 5) The mounting structure of the tension adjustment mechanism 6 to the movable body 5 is determined as a normal design matter, depending on the positional relationship between the movable body 5 and the tension adjustment mechanism 6, as well as the shape and size of the movable body 5, etc. In this embodiment, as shown in Figures 1 and 4, the holder 613 (the tension adjustment mechanism 6 including the holder 613) is mounted to the rear surface of the movable body 5 via bolts 51 and 52 in such a manner that a pair of female screw holes in the front part of the holder 613 and a pair of through holes in the movable body 5 match. This completes the mounting of the tension adjustment mechanism 6 to the movable body 5.

[0069] (Assembly of belt mechanism 1) First, the endless toothed belt 4 is fitted between the drive pulley 2 and the driven pulley 3 (between the pulleys). Although the axial distance between the pulleys is fixed, the belt mechanism 1 is configured such that, after the toothed belt 4 is fitted, tension is applied to the toothed belt 4 by the tension adjustment mechanism 6 in such a manner that the toothed belt 4 is stretched in a V-shape when viewed from the front. This makes it easier to fit the toothed belt 4 between the pulleys (for example, it can be fitted by hand (without a jig)) compared to a case where the tension adjustment mechanism 6 is not provided.

[0070] An assembly of the moving body 5 and the tension adjustment mechanism 6, which are integrated together, is attached to the toothed belt 4. In this embodiment, the assembly is attached to the toothed belt 4 by applying it from the rear to the front in the width direction of the toothed belt 4. Note that the assembly may also be attached to the toothed belt 4 by applying it from the front to the rear in the width direction of the toothed belt 4.

[0071] in particular, 6 and 7, a first engagement part through hole 611E and holder through holes 613F-613G that penetrate horizontally are formed in the first engagement part 611 and holder 613 of the tension adjustment mechanism 6, respectively. Then, in a state in which the spring 612 is compressed more than in actual use and the first engagement part 611 is pressed toward the inner bottom surface 613A of the holder 613, the split pin 70 is inserted through the first engagement part through hole 611E and the holder through holes 613F-613G, whereby the first engagement part 611 is temporarily fixed to the holder 613.

[0072] ii) Next, while sandwiching the tooth bottom portion 46 of the toothed belt 4 between the belt pressing portion 611A and the belt holding portion 611B of the first engagement portion 611, the assembly of the moving body 5 and the tension adjustment mechanism 6 is inserted from rear to front in the width direction of the toothed belt 4 so that the toothed belt 4 is positioned (overlapped) on the pair of second engagement portions 621 and 622 when viewed from above (see Figs. 6 and 7). At this time, both side surfaces of the belt holding portion 611B located on the inner circumferential surface 4B side of the toothed belt 4 are in contact with two tooth portions 44 adjacent to each other in the belt longitudinal direction (see Fig. 7).

[0073] iii) Next, the split pin 70, which was temporarily fastened while the first engagement portion 611 was pressed against the inner bottom surface 613A of the holder 613, is removed. As a result, the spring 612 presses down the first engagement portion 611, and the inner peripheral surface 4B of the toothed belt 4 comes into contact (slides) with the upper surfaces of the pair of second engagement portions 621 and 622, and the reverse-reversal prevention means 63 operates, and the ratchet pawl 631 and the ratchet teeth 632 are engaged with each other so as not to be able to reverse (see FIG. 4), and the toothed belt 4 is stretched in a V-shape in front view between the pair of second engagement portions 621 and 622 (see FIGS. 1 and 3), and the moving body 5 is fixed to the endless toothed belt 4 using the tension adjustment mechanism 6 as a fixing means, and a predetermined tension is applied to the toothed belt 4. With the above, the assembly of the belt mechanism 1 is completed. According to this configuration, the movable body 5 can be easily attached to the toothed belt 4 (without the need for a jig or fixture), thereby improving the ease of assembly of the belt mechanism 1 (while maintaining versatility).

[0074] (Belt mechanism 1 operation) According to the belt mechanism 1, the belt tension of the toothed belt 4 running between the pulleys is automatically adjusted to be constant. Specifically, if the toothed belt 4 stretches due to some reason, such as a decrease in the belt tension of the toothed belt 4 while it is running between the pulleys, the spring 612 presses the first engagement portion 611 down onto the outer circumferential surface 4A of the toothed belt 4 by the amount of slack. At this time, the first engagement portion 611 is pressed down by the biasing action of the spring 612 by the amount of slack in the toothed belt 4 (at the same time, the toothed belt 4 slides on the pair of second engagement portions 621 and 622 by the amount of slack, and is pulled from the pair of second engagement portions 621 and 622 toward the first engagement portion 611), and the ratchet pawl 631 of the reverse-reversal prevention means 63 climbs over the lower ratchet tooth 632, and the ratchet pawl 631 and the ratchet tooth 632 engage with each other in a manner that prevents reverse movement, thereby reliably eliminating the slack in the toothed belt 4 and automatically adjusting the belt tension of the toothed belt 4 to be constant while it is running.

[0075] According to the above configuration, the tension adjustment mechanism 6 to which the movable body 5 is attached is fixed to the endless toothed belt 4 in a manner in which the toothed belt 4 is clamped between a belt pressing means 61 that presses the outer peripheral surface 4A of the toothed belt 4 to apply tension to the toothed belt 4 and a support means 62 that supports the inner peripheral surface 4B of the toothed belt 4. In other words, the pressing function of the belt pressing means 61, which presses the outer surface 4A of the toothed belt 4 so as to keep the tension of the toothed belt 4 constant while it is running between the driving pulley 2 and the driven pulley 3, and adjusts the tension of the toothed belt 4 so as to keep the tension of the toothed belt 4 constant, can also serve as a fixing function for fixing the moving body 5 to the toothed belt 4 (i.e., the tension adjustment mechanism 6 itself has the function of attaching the moving body 5 to the toothed belt 4). Therefore, as in Patent Documents 1 and 2, a tension adjustment mechanism is attached to the moving body itself, ensuring space saving, but compared to a belt mechanism in which the toothed belt is formed with ends, one end of which is directly connected to the moving body and the other end of which is connected to the moving body via a tension adjustment mechanism, there is no need to connect the toothed belt (one end of the toothed belt) to the moving body via a fixing means separate from the tension adjustment mechanism (such as a fixing device for the terminal of the toothed belt), making it possible to improve the ease of assembly of the belt mechanism 1 (while maintaining versatility).

[0076] In addition, according to the above configuration, the tension adjustment mechanism 6 to which the moving body 5 is attached is fixed to the toothed belt 4 in a manner such that the toothed belt 4 is tensioned in a V-shape by the first engagement portion 611 having a belt pressing portion 611A that contacts the outer peripheral surface 4A of the toothed belt 4 by the biasing action of the spring 612, and a pair of second engagement portions 621, 622 that contact the inner peripheral surface 4B of the toothed belt 4 and are arranged on both sides of the first engagement portion 611 and spaced apart from each other along the circumferential direction of the toothed belt 4. Therefore, while the moving body 5 is stably fixed to the endless toothed belt 4, tension can be applied to the toothed belt 4, and the tension of the toothed belt 4 can be automatically adjusted to be constant while it is running.

[0077] In addition, since the belt mechanism 1 having the above-mentioned configuration further includes a reverse-back prevention means 63, when the tension of the toothed belt 4 weakens and the first engagement portion 611 (belt pressing portion 611A) slides toward the outer circumferential surface 4A of the toothed belt 4 due to the force of the spring 612, the sliding first engagement portion 611 (belt pressing portion 611A) can be prevented from returning. This makes it possible to more stably fix the moving body 5 to the endless toothed belt 4 while applying tension to the toothed belt 4, thereby automatically adjusting the tension of the toothed belt 4 to be constant while it is running.

[0078] Furthermore, in the belt mechanism 1 of the above configuration, since the first engagement portion 611 is provided with the belt holding portion 611B, the positioning of the movable body 5 relative to the toothed belt 4 in a direction parallel to the pulley center line PCL can be more reliably performed in the tension adjustment mechanism 6 compared to a case in which the belt holding portion 611B is not formed (the first engagement portion 611 is formed only by the belt pressing portion 611A), and even if the pulley layout is arranged so that the movable body 5 moves back and forth in the vertical (gravity) direction, for example, it is possible to specifically realize an embodiment in which the tension adjustment of the toothed belt 4 can be performed in a more stable and reliable manner.

[0079] (Other embodiments) In the belt mechanism 1 of the above embodiment, a tension adjustment mechanism 6 to which a movable body 5 is attached is fixed to the toothed belt 4 in such a manner that the toothed belt 4 is tensioned in a V-shape by a first engagement portion 611 having a belt pressing portion 611A that contacts the outer peripheral surface 4A of the toothed belt 4 by the biasing action of a spring 612, and a pair of second engagement portions 621 and 622 that contact the inner peripheral surface 4B of the toothed belt 4 and are arranged on both sides of the first engagement portion 611 and spaced apart from each other along the circumferential direction of the toothed belt 4. However, in addition to this configuration, the tension adjustment mechanism 6 to which the movable body 5 is attached may be fixed to the toothed belt 4 in a manner in which the toothed belt 4 is tensioned in an inverted V shape by a first engagement portion 611 having a belt pressing portion 611A that contacts the inner surface 4B of the toothed belt 4 by the biasing action of a spring 612, and a pair of second engagement portions 621 and 622 that contact the outer surface 4A of the toothed belt 4 and are arranged on both sides of the first engagement portion 611 and spaced apart from each other along the circumferential direction of the toothed belt 4. In this case, the spring 612 may be a tension spring that biases the first engagement portion 611 (belt pressing portion 611A) in a direction in which the first engagement portion 611 (belt pressing portion 611A) comes into contact with the inner circumferential surface 4B of the toothed belt 4 and pulls it toward the outer circumferential surface 4A. EXAMPLES

[0080] In the present invention, in a belt mechanism in which a moving body has a function of adjusting the tension of a toothed belt, it is necessary to provide versatility and good ease of assembly. In this embodiment, therefore, belt mechanisms according to an embodiment, a comparative example, and a reference example (hereinafter, each test specimen) were produced, and disassembly inspections and assembly tests were carried out to carry out comparative verification. The present invention will be described in more detail below with reference to examples, but the present invention is not limited to these examples.

[0081] [Belt mechanism] The belt mechanism of the embodiment uses an endless toothed belt, and has a tension adjustment mechanism attached to the moving body itself (see FIG. 1). The belt mechanism of the comparative example is configured such that a toothed belt is formed with ends and a tension adjustment mechanism is attached to the moving body itself. In detail, the belt mechanism is configured in accordance with the embodiment (where one end of the toothed belt is connected to the moving body and the other end of the toothed belt is connected to the moving body via a tension adjustment mechanism) disclosed in Patent Document 1 (JP Patent Publication 02-127313A) (see Figures 1 and 2 of Patent Document 1). The belt mechanism of the reference example is a toothed belt having two ends, one end of which is directly connected to the moving body, but does not have a tension adjustment mechanism. In other words, except for not having a tension adjustment mechanism, the belt mechanism of the reference example is configured the same as the comparative example (not shown).

[0082] (Common to each test specimen) (Toothed belt: Fig. 5) Shape of teeth: The teeth shape was an H-tooth shape belonging to straight teeth (cross section is approximately semicircular). Number of teeth: 333 -Tooth pitch(Pt):3mm Tooth height (Ht): 1.3mm Belt width: 10mm

[0083] [Materials used] (Core) Configuration: A twisted cord having the configuration shown in Table 3 was prepared as the core wire used in each toothed belt of each test specimen.

[0084] [Table 3]

[0085] The core wire (twisted cord) was produced in the following procedure. Filaments (9 micron diameter) of glass fiber (E glass fiber) designated ECG-150 as described in JIS R 3413 (2012) were aligned and prepared into three strands. The three strands were immersed in the RFL liquid (18-23°C) shown in Table 3 by passing them for three seconds, and then heated and dried at 200-280°C for three minutes to form a uniform adhesive layer on the surface. After this adhesion treatment, the three strands were first twisted with 12 twists / 10 cm, and no top twist was given, to produce a twisted cord with a diameter of approximately 0.35 mm and a single twist.

[0086] (Tooth cloth) For the tooth cloth of each specimen, a twill weave fabric was used, and the warp threads of the woven fabric were arranged to extend in the belt width direction and the weft threads were arranged to extend in the belt length direction. Elastic 66 nylon yarn (woolly processed yarn) was used for the weft thread of the woven fabric, and 66 nylon yarn was used for the warp thread. The yarn fineness of the weft thread was 44 dtex, and the warp thread was 44 dtex. The woven fabric having the above configuration was subjected to RFL treatment with the RFL treatment solution shown in Table 4. Thereafter, the fabric was subjected to adhesion treatment with a rubber paste in which a rubber composition having the same composition as that of the uncrosslinked rubber sheet shown in Table 5 was dissolved in toluene, and further, an uncrosslinked rubber sheet having the composition shown in Table 5 was laminated and coated to prepare a tooth cloth precursor.

[0087] [Table 4]

[0088] (Rubber composition) The rubber composition having the composition shown in Table 5 [rubber component: chloroprene rubber (CR)] was kneaded using a Banbury mixer, and the resulting kneaded rubber was rolled to a specified thickness using a calendar roll to produce uncrosslinked rubber sheets for forming the back part (back rubber layer) and tooth part (tooth rubber layer) that constitute each toothed belt of each test specimen. The uncrosslinked rubber sheet was press-heated at 165°C for 30 minutes to produce a crosslinked rubber sheet (100mm x 100mm x 2mm thick). A laminate of three crosslinked rubber sheets was used as a sample, and the hardness (type A) of the crosslinked rubber sheet was measured using a type A durometer in accordance with the spring-type durometer hardness test specified in JIS K6253 (2012), and was approximately 81. The ingredients marked with * in Table 5 are as follows.

[0089] [Table 5] *1 "PM-40" manufactured by Denka Co., Ltd. *2 "Nocrac MB" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. *3 "N-cyclohexyl-2-benzothiazole sulfenamide" manufactured by Ouchi Shinko Chemical Industry Co., Ltd. *4 "SeaSto 3" manufactured by Tokai Carbon Co., Ltd. *5 "Zinc oxide type 3" manufactured by Seido Chemical Industry Co., Ltd.

[0090] [Manufacturing of toothed belts] (Common to each test specimen) Each toothed belt of each test specimen was produced by the normal pressing method described in the above embodiment using the twisted cord (adhesive-treated product) constituting the core wire, the tooth cloth precursor (adhesive-treated product), and the uncrosslinked rubber sheets forming the back rubber layer and the tooth rubber layer, as described in the above-mentioned materials used. The crosslinking molding was carried out for 25 minutes using a vulcanizer under the conditions of a heating temperature of 161°C and a steam pressure of 0.63MPa. In order to configure the back part to a predetermined thickness, the back side of the crosslinked molded body (crosslinked belt sleeve) obtained by crosslinking molding was ground to a certain thickness and then cut to a certain width. The belt length of the obtained endless toothed belt was 999 mm. Since the toothed belt was produced by a normal press-fitting method, the back part (back rubber layer) and the tooth part (tooth rubber layer) are made of the same rubber composition, so that the hardness of the rubber composition constituting the back part and the rubber composition constituting the tooth part are approximately the same in each toothed belt.

[0091] (Different for each test specimen) (Example) In the examples, the endless toothed belt having a length of 999 mm obtained by the above method was used as it was. (Comparative Example) In the comparative example, a belt with ends was used, which was obtained by cutting the endless toothed belt having a length of 999 mm obtained by the above method at one position in the belt longitudinal direction. (Reference example) In the reference example, an endless toothed belt having a length of 999 mm obtained by the above method was cut at two points in the belt longitudinal direction so as to shorten it by a predetermined amount, to obtain a belt having ends.

[0092] (Pulley layout) In both the examples and comparative examples, the belt mechanisms were configured so that the drive pulley and driven pulley were straight tooth pulleys, and had a two-axis layout with fixed inter-axis spacing, and were equipped with an axle load detector (load cell) that could be connected to one of the rotating shafts (the drive pulley). The belt mechanism of the reference example had a two-shaft layout in which the drive pulley and driven pulley were straight-tooth pulleys and the distance between the shafts was adjustable (at least one pulley shaft was movable). Number of teeth on drive pulley / pulley diameter (assuming core line): 46 teeth / 43.927mm Number of teeth on driven pulley / pulley diameter (assuming core line): 46 teeth / 43.927 mm ·Speed ​​ratio: 1 Belt installation tension: The required level of belt installation tension is approximately 1N / mm width (1N per 1mm width of belt). In this specification, the belt tension measured in a stationary state immediately before actual driving is regarded as the "belt installation tension." The belt installation tension was calculated from the shaft load detected by the shaft load detector (load cell) connected to the rotating shaft of one side (the driving pulley). The center distance is set at 430mm (standard value).

[0093] (Tension adjustment mechanism) (Example) The tension adjustment mechanism of the embodiment is shown in Figures 1 to 4 (particularly Figures 3 and 4), and is composed of a belt pressing means (first engagement portion, spring, holder), a reverse return prevention means (ratchet mechanism portion), and a support means (arm portion having a pair of second engagement portions), which are formed to be integrated (one assembly). The ratchet pawl of the ratchet mechanism portion is molded integrally with the main body of the first engagement portion, and the support means (arm portion) is molded to be a part of the base body. The distance (spacing) between the first engagement portion and the pair of second engagement portions in the direction parallel to the center line of the pulley is the same on the left and right (approximately 55 mm each). The first engagement portion, the holder, and the base body were each produced by injection molding a polyacetal resin (product name "Vestal G" (manufactured by Mitsuboshi Belting Co., Ltd.)). The spring was a coil spring, and the spring wire was an oil-tempered wire for springs with a circular cross section (compliant with JIS G3560:1994).

[0094] (Comparative Example) The tension adjusting mechanism of the comparative example is shown in Figs. 1 and 2 of Patent Document 1, and is formed by a belt tensioning means (spring) and a reverse return prevention means (one-way clutch mechanism). The spring was a coil spring, and the spring wire was an oil-tempered wire for springs with a circular cross section (compliant with JIS G3560:1994). The reverse return prevention means (one-way clutch mechanism) 10 is composed of a bearing member 6, a shaft 7, a one-way clutch 8, and a pulley (toothed pulley) 9. The pulley (toothed pulley) is fixed to the shaft via the one-way clutch, and is configured so that it can rotate only in one direction (the direction in which the toothed belt is pulled) by the one-way clutch. A tension spring is connected between a guide attached to the underside of the moving body and the belt stopper, and the elastic force of the tension spring acts to apply a predetermined tension to the toothed belt.

[0095] (Installation of tension adjustment mechanism on moving body) (Example) According to the method described in the above embodiment, a tension adjustment mechanism (holder member) was bolted to the rear surface of the moving body. (Comparative Example) A tension adjustment mechanism (bearing member 6, guide member 13) was bolted to the underside of the moving body (see Figure 1 in Cited Document 1).

[0096] (Belt mechanism installation) (Example) Using the procedure described in the above embodiment, the mover / tension adjustment mechanism assembly was attached manually (without a jig) to the toothed belt that had already been installed between the pulleys in the manner shown in FIGS. First, an endless toothed belt was wound between the pulleys by hand (without a jig). Next, with the spring compressed more than in actual use and the first engagement portion pressed against the inner bottom surface of the holder, the first engagement portion was temporarily fastened with a split pin, the bottom of the teeth of the toothed belt was sandwiched between the belt pressing portion and the belt holding portion of the first engagement portion, and the belt holding portion was meshed with adjacent teeth of the toothed belt, and the movable body / tension adjustment mechanism assembly was inserted from the rear to the front in the width direction of the toothed belt so that the toothed belt was positioned (overlapping) on ​​the pair of second engagement portions when viewed from above (see Figures 6 and 7). Then, by pulling out the split pin that temporarily fastened the first engagement part, the first engagement part was lowered by the elastic force of the spring, and the movable body was stably fixed to the endless toothed belt while a predetermined tension was applied to the toothed belt. This completed the assembly of the belt mechanism.

[0097] (Comparative Example) First, one end of the toothed belt was connected to a fixture attached to the lower surface of the moving member using a jig (crimping jig). Next, the other end of the toothed belt was passed through a guide. Furthermore, the other end of the toothed belt that had been passed through the guide was passed between the one-way clutch mechanism (pulley) attached to the underside of the movable body and the movable body, and then a belt stopper was attached to the other end of the toothed belt using a jig (crimping jig). Next, the main body of the toothed belt was wrapped around the pulleys. Finally, the other end of the toothed belt was wound around a pulley, and the belt stopper facing one side while being turned around was connected to the guide with a spring. Then, the pulley of the one-way clutch mechanism rotated due to the elastic force of the spring, and the toothed belt was given a predetermined tension while fixing (connecting) the moving body between the ends of the toothed belt with ends. This completed the assembly of the belt mechanism.

[0098] (Reference example) First, one end of the toothed belt was connected to a fixture attached to the lower surface (other side) of the moving member using a jig (crimping jig). Next, using a jig (crimping jig), the other end of the toothed belt was connected to a fixture attached to the lower surface (one side) of the moving member. Furthermore, the main body of the toothed belt was wound around the pulleys (the center distance was previously set shorter than the reference value). Then, the driven pulley was moved to widen the center distance between the pulleys, so that the toothed belt was finally given a predetermined tension. This completed the assembly of the belt mechanism.

[0099] [Evaluation of belt mechanisms: items, methods, and standards] For each test specimen (Example, Comparative Example, Reference Example), versatility (whether the structure is simple) and ease of assembly (whether the belt mechanism can be assembled in a short time) were examined to determine whether a belt mechanism capable of solving the problem of the present application had been obtained.

[0100] [Disassembly inspection] (Test Method) In order to determine versatility (whether the structure is simple or not), the belt mechanism (test specimen) was disassembled and the number of fixing means for the moving body relative to the toothed belt was confirmed.

[0101] (Judgment criteria) When the number of fixing means for the movable body to the toothed belt is one, it is evaluated that the versatility of the belt mechanism (relatively simple structure) is ensured, and it is rated as A. When the number of fixing means for the movable body to the toothed belt is two or more, it is evaluated that the versatility of the belt mechanism (relatively simple structure) cannot be ensured, and it is rated as b. From the viewpoint of suitability for practical use in this application (versatility of the belt mechanism), a belt mechanism rated "A" was determined to be at the pass level.

[0102] [Assembly test] (Test Method) To assess the ease of installation (whether the belt mechanism can be installed in a short time), the time required to install the belt mechanism (installing the toothed belt, the moving body, and the tension adjustment mechanism between the pulleys) was measured. The evaluation results (assembly time) were expressed as an index, with the assembly time of the reference example set at 100.

[0103] (Judgment criteria) When the assembly time (index) was less than 100, it was determined that attaching a tension adjustment mechanism to a moving body did not lead to a deterioration in the ease of assembly of the belt mechanism, and the assembly was rated as A. When the assembly time (index) was 100 or more, it was evaluated that attaching a tension adjustment mechanism to a moving body would lead to a deterioration in the assembly of the belt mechanism, and a rating of b was given. From the viewpoint of suitability for practical use in this application (assembly of the belt mechanism), a belt mechanism rated "A" was determined to be at the pass level.

[0104] (Overall Judgment) The overall criteria for judging (ranking) a belt mechanism as capable of solving this problem were determined as follows, based on the results of the two test items mentioned above (versatility and ease of assembly). Rank A: If all of the above test items were rated as A, it was deemed to be completely problem-free for practical use and was given the highest rank. Rank B: If even one of the above test items was given a rating of b, the solution to this issue was deemed insufficient (failed).

[0105] (Verification results and considerations) The verification results are shown in Table 6.

[0106] [Table 6]

[0107] (Examples and Comparative Examples) In the case where the toothed belt is formed endless and there is only one means for fixing the toothed belt to the movable body (tension adjustment mechanism), in other words, the tension adjustment mechanism is formed so that it can serve as both fixing means (Example), the tension adjustment mechanism is not recognized as having a special design that leads to an increase in the number of fixing devices, and the versatility was rated as A. Furthermore, attaching the tension adjustment mechanism to the movable body does not lead to a deterioration in the assembling ability of the belt mechanism, the toothed belt can be assembled in a relatively short time, and the assembling ability was also rated as A (rank A in the overall evaluation).

[0108] In the case where the toothed belt is formed with ends and two fixing means for the movable body to the toothed belt are formed (two at one end and the other end of the toothed belt) (comparative example), the tension adjustment mechanism was recognized as having a special design that leads to an increase in the number of fixing devices, and the versatility was rated b. In addition, attaching the tension adjustment mechanism to the movable body led to a deterioration in the assembling ability of the belt mechanism, and the toothed belt could not be assembled in a relatively short time, and the assembling ability was also rated b (rank B in the overall evaluation).

[0109] (Effects obtained) From the above verification results, it was confirmed that the belt mechanism of the embodiment addresses the issues by forming the toothed belt endless and allowing the moving body to be attached (fixed) to the toothed belt simply by passing it through a tension adjustment mechanism, thereby providing versatility and good ease of assembly. [Explanation of symbols]

[0110] 1 Belt mechanism 2 Drive pulley 3 Driven pulley 4 Toothed belt 4A Outer surface 4B Inner surface 5. Mobile 6 Tension adjustment mechanism 61 Belt pressing means 611 First engagement part 612 Spring 613 Holder 62 Support means 621·622 Second engagement part 63 Reverse prevention measures PCL Pulley Centerline

Claims

1. A drive pulley driven by a drive source; A rotatably supported driven pulley; an endless toothed belt wound between the drive pulley and the driven pulley; a moving body that reciprocates between the driving pulley and the driven pulley along a circumferential direction of the toothed belt; A belt mechanism comprising: a belt pressing means attached to the moving body for applying tension to the toothed belt by pressing one side of the toothed belt so that the tension of the toothed belt is constant while the toothed belt is moving; and a tension adjustment mechanism having a support means for supporting the other side of the toothed belt.

2. The belt pressing means is a first engagement portion provided slidably along a thickness direction of the toothed belt and having a belt pressing portion that contacts an outer circumferential surface of the toothed belt; a spring that is tensioned along a thickness direction of the toothed belt and biases the belt pressing portion in a direction to press the belt pressing portion against an outer circumferential surface side of the toothed belt; a holder that accommodates the spring in a state in which the belt pressing portion is slidable; The support means is a pair of second engagement portions fixed to the holder and contacting an inner circumferential surface of the toothed belt at at least two points; The belt mechanism according to claim 1 , wherein the pair of second engagement portions are disposed on both sides of the first engagement portion along a circumferential direction of the toothed belt and spaced apart from each other.

3. 3. The belt mechanism according to claim 2, further comprising a back-return prevention means for preventing said belt pressing portion from sliding in a direction opposite to a biasing direction of said spring.

4. The first engagement portion is a belt holding portion that contacts an inner peripheral surface of the toothed belt and fixes a positional relationship of the moving body with respect to the toothed belt in a direction parallel to a pulley center line that connects a rotation center of the drive pulley and a rotation center of the driven pulley, and a connecting portion that connects the belt pressing portion and the belt holding portion, 4. The belt mechanism according to claim 2, wherein the belt holding portion faces the belt pressing portion across the toothed belt, and both side surfaces are formed so as to be able to come into contact with teeth of the toothed belt adjacent to each other in the circumferential direction of the toothed belt.

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