JP2005114110A - Toothed belt and belt drive mechanism - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a toothed belt and a belt drive mechanism capable of improving the accuracy in stopping and the responsiveness of a work conveying device and the like. <P>SOLUTION: A core wire 3 receiving the tensile force acting in the circumferential direction is buried in a belt main body 1 of a toothed belt. An elastic modulus of a material composing the core wire 3 is determined to be 200(GPa)-300(GPa), and an elastic coefficient per a unit width of the toothed belt is determined to be 2000(kN/inch)-3000(kN/inch). The elastic coefficient per unit width of the toothed belt is remarkably increased in comparison with a conventional one. The expansion and contraction quantity is reduced even when effective tensile force by inertia force of a conveyed matter and the like is large. A tooth groove width of a pulley tooth engaged with a belt tooth 2 is determined to be smaller than a tooth width of a belt tooth 2. A tooth part of the belt tooth 2 is compressed in the tooth width direction. The accuracy in stopping and the responsiveness of the belt transmitting mechanism are improved by the combination of the improvement of the rigidity of the synchronous belt and the reduction of the tooth groove width of the toothed pulley. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a toothed belt and a belt transmission mechanism used in, for example, a semiconductor or liquid crystal plate manufacturing apparatus or a robot driving apparatus.

  Generally, in a semiconductor or liquid crystal plate manufacturing apparatus or a robot driving apparatus, a toothed belt is often used for its transmission mechanism. The workpiece transfer device used for transferring articles in these devices is required to have particularly high stopping accuracy and responsiveness (residual vibration time and swing width). Therefore, the rigidity of the toothed belt is increased and the toothed belt expands and contracts. The position shift and the vibration due to are suppressed.

For example, in Patent Document 1, an elastic coefficient required per belt width is calculated in correspondence with the pulley pitch diameter, and the material and diameter of the filament, the number of filaments of one core wire, the core wire so as to obtain this elastic coefficient The number of theoretical inputs is set. In Patent Document 1, when pulley teeth are 5 mm pitch and 20 teeth (pulley pitch diameter: 31.83 mm), a core wire made of high-strength glass fiber having a filament elastic modulus of 8700 kgf / mm ² is used. The elastic modulus is set to 65000 kgf / inch or more.
JP 2001-349382 A (paragraph numbers 0012 to 0013, 0039 to 0043)

  However, when a heavy article such as a liquid crystal plate is conveyed, since the inertial force of the article is large, the stopping accuracy and responsiveness of the conveyance unit are more likely to be lowered. In order to compensate for this decrease in stopping accuracy and responsiveness, in addition to increasing the elastic coefficient of the toothed belt as described above, it is conceivable to eliminate backlash in the meshing of the toothed belt and the toothed pulley. Even with these methods, the stopping accuracy and responsiveness may not reach the required level. Further, as the inertial force of the article increases, the durability of the belt tends to be insufficient, and the life of the belt tends to be shortened.

  It is an object of the present invention to provide a toothed belt and a belt transmission mechanism that can improve stop accuracy and responsiveness of a workpiece transfer device or the like.

  In view of the above problems, the present invention is a toothed belt wound around a toothed pulley, and acts on the belt body formed with a belt tooth meshing with the pulley tooth of the toothed pulley in the circumferential direction of the toothed belt. Provided is a toothed belt in which the elastic coefficient per unit width is set to 2000 (kN / inch) to 6000 (kN / inch) on the premise of the structure in which the core wire responsible for the tension is embedded.

  According to this configuration, the elastic coefficient per unit width of the toothed belt is significantly larger than the elastic coefficient per unit width of the conventional toothed belt (for example, 65000 kgf / inch = 637 kN / inch). Even when the effective tension due to the inertial force of the conveyed product is large, the amount of expansion and contraction can be reduced to improve the stopping accuracy and responsiveness.

  Here, the elastic modulus per unit width indicates the rigidity against the tension of the toothed belt, and the tension acting on the toothed belt per unit width is divided by the amount of strain (the amount of expansion / contraction per unit length). It is a thing. The elastic modulus per unit width is obtained by multiplying the cross-sectional area of the core wire by a predetermined number of core wires per unit width and multiplying this by the elastic modulus of the material constituting the core wire.

  The elastic modulus per unit width of the toothed belt can be increased by increasing the cross-sectional area of the core wire, the predetermined number or the elastic modulus of the material, but even if the rigidity of the core wire is increased beyond a certain limit. Since the deformation of the portion of the belt main body that holds the core wire and the tooth portion is relatively large, it is difficult to obtain the effect of reducing the apparent amount of expansion and contraction of the toothed belt. Here, the upper limit of the elastic coefficient per unit width of the toothed belt is set to 6000 (kN / inch) in consideration of the material available for the core and the arrangement space.

If the elastic modulus of the material constituting the core wire is set to 200 (GPa) to 600 (GPa), than the conventional core wire made of high-strength glass fiber (for example, filament elastic modulus: 8700 kg / mm ² = 85 GPa), The elastic modulus per unit width of the toothed belt can be greatly increased without greatly changing the cross-sectional area, and the bending fatigue resistance of the core wire and the toothed belt is not impaired. Examples of the material of the core wire constituting the core wire include steel and carbon. The upper limit of the elastic modulus is set to 600 (GPa) in consideration of the material that can be obtained from the core wire.

  Further, as a more preferable range, the elastic modulus per unit width of the toothed belt is set to 2000 (kN / inch) to 3000 (kN / inch), and the elastic modulus of the material constituting the core is 200 (GPa) to Set to 300 (GPa). Thereby, even when a toothed belt is wound around a relatively small diameter toothed pulley, the bending fatigue property can be improved.

  Further, in the present invention, on the assumption that the toothed belt is wound around the toothed pulleys on the driving side and the driven side, the toothed belt is formed so as to mesh with the pulley teeth of the toothed pulley. This is a structure in which a core wire having a tension acting in the circumferential direction of the toothed belt is embedded in the belt body, and the elastic coefficient per unit width of the toothed belt is 2000 (kN / inch) to 6000 (kN / inch). The belt transmission mechanism set in is provided.

  In this belt transmission mechanism, the tooth gap width at the half of the tooth depth of the pulley teeth is set to be smaller than the tooth width of the belt teeth. That is, the tooth width in the vicinity of the pressure surface of the belt teeth is made larger than the tooth gap width of the pulley teeth in contact therewith. Thereby, the pressure surface of the belt teeth and the surface on the opposite side can be pressed to keep the belt teeth engaged with the pulley teeth in a compressed state, and the vibration of the belt teeth can be forcibly suppressed.

  The range of reducing the tooth gap width of the pulley teeth is in the range of 0.18 (mm) to 0.28 (mm) than the tooth width of the belt teeth at a depth of ½ of the tooth gap depth. It is preferable to set a small value. That is, if it is 0.18 (mm) or less, it is difficult to obtain the effect, and if it is 0.28 (mm) or more, it is easy to cause a meshing failure between the belt teeth and the pulley teeth.

  The tooth gap depth of the pulley teeth is increased, and a gap allowing deformation due to compression of the belt teeth is formed between the bottom of the pulley teeth and the tip of the belt teeth. Then, a part of the compressed portion of the belt teeth can be released into this gap, so that the tooth gap width of the pulley teeth can be obtained without causing poor meshing of the belt teeth and the pulley teeth and without impairing the durability. Can be reduced. Thereby, the amount of belt tooth compression can be increased and the vibration of the belt teeth can be more effectively suppressed.

  In the cross section along the circumferential direction of the toothed pulley, if the cross sectional area of the tooth groove of the pulley tooth is set smaller than the cross sectional area of the tooth portion of the belt tooth, the gap in the meshing state of the belt tooth and the pulley tooth can be eliminated. The vibration of the tooth portion due to the meshing gap can be prevented.

  The rubber constituting the belt body preferably has a hardness of 75 (Duro A) to 93 (Duro A). Here, the hardness of the rubber is indicated by a value in a type A durometer according to a test method for an automobile toothed belt (automobile standard, JASO E110: 2000).

  When the rubber hardness is 75 (duro A) or less, the belt teeth are greatly deformed by meshing with the toothed pulley, so the belt teeth are vibrated, the damping time is increased, and the positional accuracy and responsiveness are increased. Both are inferior. On the other hand, when the hardness of the rubber is 93 (duro A) or more, the pulley teeth and the belt teeth are difficult to mesh with each other, the flexibility of the toothed belt is lowered, and the bending fatigue property of the toothed belt tends to be inferior. .

  The magnitude of the attachment tension (T0) is set so that the attachment tension (T0) of the toothed belt and the effective tension (Te, load tension) satisfy the relationship of Te / 4 <T0 <Te. Then, the belt teeth can be pushed into the tooth space of the pulley teeth by a suitable mounting tension (T0), and the pressure surface of the belt teeth and the opposite surface can be pressed. The durability of the attached belt can be increased. When T0 <Te / 4, the tooth portion of the belt tooth cannot be sufficiently compressed, and when T0> Te, the amount of belt tooth compression becomes excessive.

  By mounting the belt transmission mechanism of the present invention on a work transfer device having a placement portion for placing an article and a swingable arm connected to the placement portion, the arm can be swung. If the mounting portion is moved, a preferred aspect of the present invention can be provided.

  According to the present invention, since the elastic coefficient per unit width of the toothed belt is significantly larger than that of the conventional one, the expansion and contraction of the toothed belt due to the effective tension is suppressed without increasing the belt width, and the durability thereof is increased. Can be improved. As a result, it is possible to improve the stopping accuracy and responsiveness of a workpiece transfer device that transfers heavy objects, and to extend the life of the toothed belt.

  Hereinafter, the best mode for carrying out a belt transmission mechanism according to the present invention will be described with reference to the drawings. FIG. 1 is a perspective view of a main part of a toothed belt according to the present invention.

  This toothed belt is wound around a toothed pulley and forms a part of a belt transmission mechanism. An annular belt body 1, a belt tooth 2 meshing with a pulley tooth of a toothed pulley, and a belt body 1 And a high-rigidity core wire 3 embedded in the toothed belt and acting on the circumferential direction of the toothed belt, and a tooth cloth 4 attached so as to cover the belt teeth 2 from the inner peripheral side.

  The belt body 1 is made of rubber such as H-NBR (hydrogenated acrylonitrile butadiene rubber), CR (chloroprene rubber), NR (natural rubber), and various rubber materials can be adopted according to the required characteristics. The The hardness of the rubber constituting the belt body 1 is 75 (Duro A) to 93 (Duro A).

  The belt teeth 2 are formed by forming a large number of convex teeth 5 along the belt width direction on the inner peripheral surface of the belt body 1 evenly in the belt circumferential length direction. The tooth gap width of the pulley teeth meshing with the belt teeth 2 is 0.18 (mm) to 0.28 (mm) than the tooth width of the belt teeth 2 at a depth that is ½ of the tooth gap depth. It is made small in the range, and the pressure surface of the tooth portion 5 and the opposite surface are pressed by pushing the tooth portion 5 of the belt tooth 2 into the tooth space of the pulley tooth.

  The core 3 is formed by bundling a large number (for example, 12,000) of filaments such as carbon and steel, and twisting the bundle of filaments as necessary. It arrange | positions so that it may contact | adhere. The filament constituting the core wire 3 has a diameter of, for example, about 4 to 7 μm and an elastic modulus of 200 (GPa) to 300 (GPa), and a predetermined number (for example, about 16 to 22 per 1 inch belt width). By embedding the core 3, the elastic coefficient per unit width of the toothed belt is set to 2000 (kN / inch) to 3000 (kN / inch).

  The tooth cloth 4 is made of nylon, for example, and is endlessly processed and formed into a cylindrical shape by sewing or welding (for example, ultrasonic welding). The tooth cloth 4 is configured by arranging stretchable weft yarns 6 made of bulky processed yarns in the circumferential direction and non-stretchable warp yarns 7 made of filament yarns in the belt width direction. As a result, the tooth cloth 4 has an extension in the circumferential direction, and the tooth portion 5 and the like can be formed at the time of rubber vulcanization molding, and the flexibility of the toothed belt is ensured.

  As a manufacturing procedure of the toothed belt, first, a cylindrical mold having a groove corresponding to the belt tooth 2 on the surface is covered with a cylindrical tooth cloth 4, and the core wire 3 is placed thereon by a winding device. Wrap evenly. An unvulcanized rubber sheet is wound on the belt, and a belt molded body having belt teeth 2 is manufactured by pressure vulcanization. The molded body is subjected to surface treatment, and then cut to a desired belt width by a cutter device. do it.

  Next, differences in the stopping accuracy, responsiveness, and durability of the belt transmission mechanism due to differences in the elastic coefficient per unit width of the toothed belt, the tooth shape, and the mounting tension will be described. In order to verify these differences, three types of test belts having different elastic coefficients per belt unit width shown in Tables 1 and 2 and three types of toothed pulleys shown in FIGS. 2 to 3 are combined. Then, a positional accuracy test, a responsiveness test, and a durability test were performed.

  First, each test belt will be described. Table 1 shows the configuration of three types of core wires (conventional standard belt, high rigidity belt 1) and 2)) used for the test belt, and Table 2 shows the predetermined number of core wires per unit width of the test belt. The number and elastic modulus are shown.

  As shown in Table 1, the core wire 3 of the conventional standard belt is formed by impregnating a 9 μm diameter filament made of E glass into resorcin / formalin latex (RFL) and bundling 200 of these to form a strand, Three strands are bundled and twisted to form a small rope, and 11 small ropes thus formed are bundled. The core 3 of the high-rigidity belts 1) and 2) is formed by bundling 12,000 filaments made of carbon having a diameter of 7 μm and adding some twist.

As shown in Tables 1 and 2, the conventional standard belt has 18 cores 3 per inch with a cross-sectional area of about 0.42 mm ² and an elastic modulus of 73 GPa. The coefficient is 548 kN / inch. The high-rigidity belt 1) (2)) has 22 (20) core wires 3 per inch, each having a cross-sectional area of about 0.46 mm ² and an elastic modulus (tensile elastic modulus) of 235 GPa. The hit elastic modulus is 2390 (2172) kN / inch.

  Fig. 2 shows the shape of the tooth groove of a conventional standard toothed pulley, Fig. 3 shows the shape of the tooth groove of a pulley with a tooth width reduced according to the present invention (lower limit), and Fig. 4 shows the tooth width reduced and tooth groove depth of the present invention. It is a tooth space part shape of an increase toothed pulley (upper limit). The pulley teeth 8 in FIG. 2 have a tooth gap width substantially equal to the tooth width of the belt teeth 2, and a backlash 9 is formed near the tip of the pulley teeth 8.

  The pulley teeth 8 in FIG. 3 have a tooth gap width at a depth that is ½ of the tooth groove depth smaller than the tooth width of the belt teeth 2 by 0.18 mm (one side 0.09 mm). When the pulley teeth 8 and the belt teeth 2 mesh with each other, the compression portion 10 of the tooth portion 5 is compressed in the tooth width direction.

  The pulley teeth 8 in FIG. 4 have a tooth gap width at a half of the tooth groove depth and a tooth groove width at a half of the tooth height of the belt tooth 2. It is smaller than the tooth width by 0.28 mm (0.14 mm on one side). When the pulley teeth 8 and the belt teeth 2 mesh with each other, the compression portion 10 of the tooth portion 5 is compressed in the tooth width direction.

  In the pulley tooth 8 of FIG. 4, a gap 11 is formed between the tooth bottom and the tooth tip of the belt tooth 2 to allow deformation by compressing the tooth portion 5 of the belt tooth 2. A part of the compression deformation of the tooth portion 5 is allowed to escape. In the cross-section along the circumferential direction of the toothed pulley, the cross-sectional area of the tooth groove of the pulley tooth 8 is set smaller than the cross-sectional area of the tooth portion 5 of the belt tooth 2, and the cross-sectional area of the gap 11 is that of the compression portions 10 on both sides. It is smaller than the total cross-sectional area.

  Each test belt has a tooth pitch of 8 mm, a circumference of 1000 mm, a belt width of 20 mm, and a tooth cloth made of nylon. As for the rubber type of the belt body 1, the conventional standard belt is CR and its hardness is 70 (duro A), and the high rigidity belts 1) and 2) of the present invention are H-NBR and its hardness is 88 ( Duro A).

  Next, the procedure and result of the positional accuracy test of the belt transmission mechanism will be described. This positional accuracy test measures the relationship between the magnitude of the shaft torque (N · m) when the shaft torque is applied to the driven pulley 13 and the angle deviation (°) of the driven pulley 13. .

  FIG. 5 is a schematic view of a stop accuracy measuring machine used for the position accuracy test, where (a) is a plan view and (b) is a side view. This stop accuracy measuring machine includes a driving pulley 12 and a driven pulley 13 that wrap around a test belt, a stepping motor 14 that rotationally drives a pulley shaft of the driving pulley 12, and an arm 15 that is fixed to the pulley shaft of the driven pulley 13. , An inertial load 16 fixed to the tip of the arm 15, and encoders 17, 18 disposed on the pulleys 12, 13.

  The driving pulley 12 is rotated forward and backward by a predetermined angle (for example, 90 °) by the stepping motor 14, and the angle deviation when the inertial load 16 is stopped is measured by the driven encoder 18.

  Fig. 6 differs from the two types of toothed pulleys (tooth width reduction, tooth depth increase toothed pulley (upper limit), tooth width reduced toothed pulley (lower limit)) and the elastic modulus per unit width is different. The result of the positional accuracy test performed by combining two types of test belts (standard belt, high-rigidity belt 1) is shown.

  As shown in FIG. 6, the amount of angular deviation of the driven pulley 13 increases so as to be substantially proportional to the axial torque. The amount of misalignment corresponding to the same amount of shaft torque is high rigidity belt 1 in both cases of toothed pulley with reduced tooth width and increased tooth depth (upper limit) and toothed pulley with lower tooth width (lower limit). ) Is significantly less than that of the standard belt. Thereby, it turns out that the stop precision of a belt transmission mechanism can be improved by using a highly rigid belt. Note that the amount of misalignment in the case of toothed pulley with reduced tooth gap width and increased tooth depth (upper limit) is less than the amount of misalignment of toothed pulley with lower tooth groove width (lower limit). The effect of width reduction can be recognized.

  Next, the procedure and result of the response test of the belt transmission mechanism will be described. This responsiveness test is to measure the deflection width of the angular deviation (°) in the driven pulley 13 when an inertia force (2.65 N · m) having a constant magnitude is applied to the driven pulley 13.

  FIG. 7 is a schematic view of a stop accuracy measuring machine used for the responsiveness test, where (a) is a plan view and (b) is a side view. This stop accuracy measuring machine is the same as that used in the position accuracy test, but includes a laser displacement meter that detects the swing width of the inertial load 16. The laser displacement meter is arranged opposite to the inertial load 16 at the stop position of the inertial load 16, and detects the fluctuation width of the inertial load 16 near the stop position.

  Here, the stop position of the inertial load 16 is set above the pulley shaft of the driven pulley 13 to eliminate the influence of gravity. In addition, by confirming the stop position of the inertial load 16 based on the rotational displacement difference between the driving side encoder 17 and the driven side encoder 18, the deviation due to the change of the test belt with time is confirmed, and the origin position of the vibration displacement is determined. ing.

  The driving pulley 12 is rotated forward and backward by a predetermined angle (for example, 90 °) by the stepping motor 14, and the swing width when the inertial load 16 is stopped is measured by a laser displacement meter.

  Fig. 8 shows three types of toothed pulleys (standard toothed pulley, toothed groove width reduced / toothed tooth depth increased toothed pulley (upper limit), toothed groove width reduced toothed pulley (lower limit)), and per unit width. Is a graph showing the results of a responsiveness test performed by combining three types of test belts (standard belt, high-rigidity belt 1), 2)) with different elastic moduli, and when an inertial force is applied to each test belt This shows the first deflection width (maximum deflection width) of the angle deviation amount (°) in the driven pulley 13.

  As shown in FIG. 8, if attention is paid to the elastic coefficient per unit width of the test belt for each toothed pulley, the runout width in the high-rigidity belts 1) and 2) is smaller than the runout width in the standard belt. Thereby, it turns out that the responsiveness of a belt transmission mechanism can be improved by using a highly rigid belt. If attention is paid to the tooth groove shape of the toothed pulley for each elastic coefficient per unit width, the toothed pulley (upper limit) and the toothed groove with the tooth width reduced and the tooth depth increased compared to the runout width of the standard toothed pulley. The runout width in the pulley with a width reduction tooth (lower limit) is small. Thereby, it turns out that the responsiveness of the belt transmission mechanism can be improved by reducing the tooth gap width of the pulley teeth.

  9 to 11 are diagrams showing the relationship between the passage of time after the inertial force is applied and the fluctuation width of the angle deviation amount (°). As shown in these figures, when an inertial force is applied to each test belt, the driven pulley 13 swings in the forward and reverse directions, and its swing width decreases as time passes. FIG. 8 shows a result obtained by extracting the first deflection width.

  FIG. 9 shows the test results of a combination of a standard belt and a standard toothed pulley, and a combination of a standard belt and a tooth width reduced toothed pulley (lower limit). FIG. 10 shows a combination of a high-rigidity belt 1) with a toothed pulley (upper limit) with a reduced tooth gap width and an increased tooth gap depth, and a combination of a high-rigidity belt 2) with a toothed pulley with a reduced tooth gap width (lower limit). It is a test result. FIG. 11 shows a combination of a high-rigidity belt 1) and a toothed pulley with a reduced tooth gap width (lower limit), and a combination of a high-rigidity belt 1) with a toothed pulley with a reduced tooth gap width and increased tooth gap depth (upper limit). It is a test result. The figure which shows the test result by another combination is abbreviate | omitted.

  Next, the procedure and results of the durability test will be described. This durability test is to examine the difference in the durability of the test belt due to the difference in the mounting tension (T0). The time until the test belt is damaged and cannot run is measured.

  The number of pulley teeth of the driving pulley and the driven pulley is 22 teeth, the number of rotations is 2300 rpm, and the load torque is 29.4 N · m (effective tension 1050 N). The attachment tension (T0) is a tension in a state where no load torque is applied. The effective tension (Te) is a load tension due to a load torque, and is equal to the difference between the tension side tension (Ts) and the loose side tension (Tt).

  FIG. 12 is a result of the durability test, and is a diagram showing belt running time (durability) for each attachment tension. As shown in FIG. 12, when the mounting tension is 500 N, it can be seen that the traveling time has reached 1000 (hr). Further, when the mounting tension is 265 N, the durability of the high-rigidity belt of the present invention is slightly higher than the durability of the conventional standard belt, and if the mounting tension is 265 N or less, the durability cannot be improved. Understand.

  If this is shown by the relationship between the mounting tension (T0) and the effective tension (Te), sufficient durability is exhibited when T0 = Te / 2, and it can be said that the durability cannot be improved when T0 <Te / 4. . Moreover, since it is thought that durability will be reduced conversely if attachment tension (T0) is made unlimited, it is good to set it as T0 <Te. It is preferable to set the magnitude of the mounting tension (T0) so that these results are put together and the relationship of Te / 4 <T0 <Te is satisfied.

  Next, the workpiece conveyance apparatus provided with the belt transmission mechanism of this invention is demonstrated. FIG. 13 is a side view of the workpiece transfer device. This work transport device moves a fork 19 by placing a fork 19 (placement unit) on which an article (work) is placed, three swingable arms 20 that support the fork 19, and swinging the arm 20. Belt transmission mechanism.

  Both ends of the arm 20 are rotatably connected to a pulley shaft 21, and the arms 20 are connected to the arm shaft 20 through the pulley shaft 21 so as to be swingable in order. Further, the base end of the base end side arm 20a is rotatably connected to the support shaft 21a, and the fork 19 is connected to the tip end of the front end side arm 20c via the pulley shaft 21.

  The belt transmission mechanism includes a toothed pulley 22 provided at both ends of each arm 20 and a toothed belt 23 wound around the toothed pulley 22. The pulley shaft 21 that connects the distal end of the proximal end arm 20a and the proximal end of the intermediate arm 20b is connected to a motor 24 that rotationally drives the pulley shaft 21, and the other pulley shaft 21 is connected to a speed reducer 25. Has been. By swinging each arm 20 by the motor 24, the fork 19 moves in a predetermined direction.

  According to the above configuration, the high elastic modulus core wire is embedded in the toothed belt, the elastic coefficient per unit width of the toothed belt is greatly increased, and the extension of the toothed belt due to the effective tension is suppressed. . In addition, by reducing the tooth gap width of the pulley teeth and keeping the tooth portions of the belt teeth pushed into the tooth spaces of the pulley teeth in a compressed state in the tooth width direction, the inertia force of the workpiece can be increased without increasing the belt width. Can suppress the swinging of the fork and improve its stopping accuracy and responsiveness.

  In addition, since the durability of the toothed belt can be improved by setting the magnitude of the mounting tension within a suitable range, the life of the toothed belt used in the work conveying device for conveying heavy objects can be extended. Can be planned.

The principal part perspective view of the toothed belt which concerns on this invention Tooth groove shape of conventional standard toothed pulley Tooth gap shape of the tooth width reduced tooth pulley (lower limit) of the present invention Tooth groove shape of toothed pulley (upper limit) with tooth width reduced and tooth depth increased according to the present invention Schematic of stop accuracy measuring machine used for position accuracy test Position accuracy test results Schematic of stop accuracy measuring machine used for responsiveness test Response test results Diagram showing the relationship between the passage of time and the amplitude Figure showing the relationship between the passage of time and the amplitude Figure showing the relationship between the passage of time and the amplitude Durability test results Side view of workpiece transfer device

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Belt main body 2 Belt tooth 3 Core wire 5 Tooth part 8 Pulley tooth 10 Compression part 11 Crevice

Claims (11)

A toothed belt wound around a toothed pulley, wherein a core wire having a tension acting in a circumferential direction of the toothed belt is formed on a belt body formed with a belt tooth meshing with a pulley tooth of the toothed pulley. Buried,
A toothed belt, wherein an elastic coefficient per unit width of the toothed belt is set to 2000 (kN / inch) to 6000 (kN / inch).   The toothed belt according to claim 1, wherein an elastic modulus of a material constituting the core wire is set to 200 (GPa) to 600 (GPa).   The toothed belt according to claim 1, wherein an elastic coefficient per unit width of the toothed belt is set to 2000 (kN / inch) to 3000 (kN / inch).   The toothed belt according to claim 3, wherein an elastic modulus of a material constituting the core wire is set to 200 (GPa) to 300 (GPa). A belt transmission mechanism in which a toothed belt is wound around a driving-side and driven-side toothed pulley,
The toothed belt includes a belt body in which a belt tooth that meshes with a pulley tooth of the toothed pulley is formed, and a core wire that bears a tension acting in a circumferential direction of the toothed belt is embedded. The elastic modulus per unit width is set to 2000 (kN / inch) to 6000 (kN / inch),
A belt transmission mechanism in which the pulley teeth have a tooth gap width at a depth that is ½ of the tooth gap depth smaller than the tooth width of the belt teeth.   In the pulley teeth, a tooth gap width at a half of the tooth gap depth is set to be smaller in a range of 0.18 (mm) to 0.28 (mm) than a tooth width of the belt teeth. The belt transmission mechanism according to claim 5.   6. The pulley tooth according to claim 5, wherein the pulley teeth are set to a tooth gap depth in which a gap allowing deformation due to compression of the belt teeth is formed between the bottom of the teeth and the tip of the belt teeth. 6. A belt transmission mechanism according to 6.   The belt transmission according to claim 7, wherein a cross-sectional area of a tooth groove of the pulley tooth is set smaller than a cross-sectional area of a tooth portion of the belt tooth in a cross section along a circumferential direction of the toothed pulley. mechanism.   The belt transmission mechanism according to any one of claims 5 to 8, wherein the belt main body is made of rubber having a hardness of 75 (Duro A) to 93 (Duro A).   The size of the mounting tension (T0) is set so that the mounting tension (T0) and the effective tension (Te) of the toothed belt satisfy the relationship of Te / 4 <T0 <Te. The belt transmission mechanism according to any one of claims 5 to 9.   Equipped in a work transfer device having a placement part for placing an article and a swingable arm communicated with the placement part, and the placement part is moved by swinging the arm. The belt transmission mechanism according to any one of claims 5 to 10.

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