JP2001349382A - Residual vibration reducing belt - Google Patents

Abstract

PROBLEM TO BE SOLVED: To make responsiveness of a belt excellent and to improve durability. SOLUTION: A strand is formed by building filaments made of high-strength glass fiber, and a thin rope is formed by bundling three strands. A core wire 5 to be buried into the belt is formed by bundling 11-13 of obtained thin ropes to make responsiveness and durability excellent.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a residual vibration reduction belt having excellent responsiveness and durability, which is used in a manufacturing apparatus for printed circuit boards and semiconductors, and a driving apparatus such as a robot.

[0002]

2. Description of the Related Art FIG. 1 is a perspective view of a work transfer device used in a printed circuit board manufacturing apparatus. As shown in the drawing, the work transfer device 1 has a work mounting table 6 fixed on a pair of timing belts 4 and 5 wound around pulleys 2 and 3, and a work board such as a printed circuit board or a semiconductor device is fixed to the mounting table 6. 7 is mounted, and the timing belts 4 and 5 run via the pulleys 2 and 3 by driving of the motor 8 to convey the work 7. When the work 7 is conveyed at a constant speed, predetermined processing is performed. And send it to the next process.

FIG. 2 is a perspective view of a timing belt used in the work transfer device. The timing belts 4 and 5 include a rubber belt main body 11, a toothed portion 12 formed on the inner peripheral surface of the belt main body, and a tooth cloth 13 adhered to the inner peripheral surface of the toothed portion 12. And a core wire 14 embedded in the belt main body 11.

[0004]

In recent years, in the manufacture of the above-mentioned printed circuit boards and semiconductor devices,
In order to improve the productivity, the transport belt is also required to have excellent responsiveness.

FIG. 3 is a diagram showing the response characteristics of the timing belt in the work transfer device 1, wherein the driving speed of the timing belt is shown on the vertical axis and the time is shown on the horizontal axis. In the drawing, after being accelerated by driving the pulley, if it has been accelerated to a predetermined speed, it is operated at a constant speed for a time necessary for processing,
It had been decelerated and stopped.

[0006] However, the timing belt itself is
Because it is made of a rubber-like elastic body, if it is suddenly accelerated or suddenly stopped, the belt expands and contracts, and the expansion and contraction of the belt appears as residual vibration. If the residual vibration remains, it is not possible to immediately enter the next step, and it is necessary to suspend the operation until the residual vibration stops.

In addition, if the swing width in the circumferential direction of the belt increases as well as the time in the residual vibration, the work 7 such as a printed circuit board or a semiconductor device may be displaced with respect to the mounting table 6 due to the inertial force. There is. Therefore, as the characteristics of the timing belt, not only the above-mentioned residual vibration time is short but also the fluctuation width thereof is required to be small.

Further, as a general responsiveness of the timing belt, it is required not to cause a jumping phenomenon in which the engagement with the teeth of the pulley is caused to fly, and high durability is required.

[0009]

Means for Solving the Problems The present inventors have paid attention to the above-mentioned problems and have conducted intensive studies on belts satisfying various characteristics required for a timing belt. As a result, the rubber, core wire, and tooth cloth constituting the belt have been studied. Among them, it has been found that the core wire that regulates the circumference of the belt most contributes to the reduction of the residual vibration.

Based on this knowledge, experiments were conducted on various core wires made of glass fiber, and as a result, the number of pulley teeth on which the belt was stretched was 20 at a pitch of 5 mm (the minimum pulley diameter was 3).
(1.83 mm), when a bundle of 6,600 filaments of 9 μm in diameter made of high-strength glass fiber is used as the core wire, the residual vibration time is short, the swing width is small, and the jumping phenomenon is caused. And high durability was obtained.

The above-mentioned optimum core wire configuration is such that the pulley teeth are 5 m.
It is assumed that there are 20 teeth with a m pitch (the minimum pulley diameter is 31.83 mm). When the number of pulley teeth, that is, the diameter of the pulley increases, the responsiveness (residual vibration time and swing width) and durability (bending characteristics) may be improved even with other core wire configurations.

The inventors of the present invention have examined the results of various experiments as to whether or not there is a rule. As a factor affecting the responsiveness and durability, the elastic modulus required per belt width is used. Based on this finding, if the material, diameter, and number of filaments constituting the core wire are set so as to satisfy the following expression (1), the responsiveness and durability will be good. Was found. That is, the elastic modulus required per belt width ≦ the cross-sectional area per core wire × the number of theoretical driving wires × the elastic modulus of the filament (1)

Further, the relationship between the diameter of the pulley on which the belt is stretched and the diameter of the pulley on which the belt is stretched was examined. The elastic coefficient required per belt width satisfies the following expression (2) in accordance with the diameter of the pulley on which the belt is stretched. It has been found that the responsiveness and the durability are improved when the setting is made. Elastic coefficient required per belt width = -0.0544 x (pulley pitch diameter) ² (mm) +397.45 x (pulley pitch diameter) +61362 (2) If a core wire with such a high elastic coefficient is used, the belt Since the elongation of the belt is reduced, the stopping accuracy of the belt can be improved accordingly.

[0014]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The details of the present invention as a result of various experiments will be described below with reference to the drawings. The basic configuration of the residual vibration belt is the same as that of the belt shown in FIG. 2, and the field of application of the belt is applied to the transport belt of a workpiece transport device such as a printed circuit board or a semiconductor device shown in FIG. Therefore, please refer to these drawings as appropriate.

As shown in FIGS. 1 and 2, the residual vibration reduction belts 4 and 5 are endless belts used as the transport timing belt shown in FIG. A toothed portion 12 formed on a peripheral surface, a tooth cloth 13 adhered to an inner peripheral surface of the toothed portion 12,
And a core wire 14 embedded in the belt main body 11.

The toothed portion 12 is a convex portion formed along the belt width direction. The toothed portion 12 is formed evenly in the belt circumferential direction so that it can be engaged with the tooth portions of the pulleys 2 and 3 to be stretched. Have been.

The tooth cloth 13 has elongation in the circumferential direction so that a convex portion or the like can be formed at the time of vulcanization molding of rubber, and in order to secure flexibility of the belt. ,
A nylon tooth cloth having a thickness of about 3 mm is formed by endless processing into a cylindrical shape by sewing, welding (for example, ultrasonic welding), or the like.

The rubber constituting the belt body 11 is CR
Various rubber materials such as (chloroprene rubber) and NR (natural rubber) can be adopted according to the required characteristics of the belt.

The core wire 14 is formed by impregnating a filament made of glass fiber having a diameter of 7 to 9 μm with resorcinol-formalin resin latex (RFL), and then bundling 200 of them to form a strand. The lower rope is twisted to form a small rope, and 8 to 18 small ropes thus formed are bundled and configured.

The core wire 14 is provided on the tooth cloth 1 on the toothed portion 12.
3, 16 to 22 are buried per inch (25.4 mm) in the belt width direction.

In manufacturing the belt, a cylindrical mold cloth 7 having a groove corresponding to the toothed portion 4 on its surface is covered with a cylindrical tooth cloth 7 extending in the circumferential direction. The core wire 5 is evenly wound by a winding device, an unvulcanized rubber sheet is wound thereon, and by pressure vulcanization, a belt molded body having a belt main body 11 and a toothed portion 12 is manufactured. After the surface treatment, the sheet is cut to a desired belt width by a cutter device to obtain a residual vibration reduction belt.

Table 1 shows the types of glass fibers constituting the core wire,
The thickness, the number of strands, the number of small ropes, the diameter of the core wire, the number of core wires, the number of core wires driven (spi), the width occupied by the core wire and the rubber are variously changed, and the residual vibration time and circumferential swing width, and traveling It is a summary of the results of a durability bending test at a time of 2000 hrs.

[0023]

[Table 1]

The glass fibers used were E glass and U glass. U glass fiber (Nippon Glass Fiber Co., Ltd.)
Is a high-strength glass fiber, other than this U glass fiber,
T glass fiber (Nitto Boseki Co., Ltd.), R glass fiber (Vetr
otex Saint Gobain), S glass fiber (Owens Corn)
ing Fiberglass). The compositions and physical properties are shown in Tables 2 and 3.

[0025]

[Table 2]

[0026]

[Table 3]

The high-strength glass fiber filament has a SiO ₂ component, Al ₂ O ₃
Component, while the content of MgO component is increasing,
The content ratios of the CaO component and the B ₂ O ₃ component are decreasing. The high-strength glass fiber has a higher elastic modulus than the E glass fiber.

In Table 1, the number of cores is the number of cores per belt width (20 mm), and the number of spi means the number of cores per inch (25.4 mm) of belt width. The core wire occupancy width is the core wire occupancy width in the belt width (20 mm), and the rest means the total width of the rubber interposed between the core wires. The rubber used for the main belt and the toothed portion is made of CR,
Numeral 3 is made of nylon, the warp is a filament yarn, and the weft is a bulky processed yarn. In FIG. 2, the stretchable weft 17 is arranged in the circumferential direction, and the non-stretchable warp 18 is arranged in the belt width direction.

The residual vibration time and the swing width were measured using a residual vibration tester shown in FIGS. FIG. 4 is a schematic plan view of the residual vibration tester, and FIG. 5 is a front view thereof. As shown, the residual vibration tester 20 is a two-axis tester,
Pulleys 21 and 22 on which a test belt is stretched, a stepping motor 24 for rotating and driving a pulley shaft 23 of one of the pulleys 21, an arm 26 fixed to a pulley shaft 25 of a driven pulley 22, and a tip of this arm An inertial load 27 fixed to the pulley, a laser displacement meter 28 disposed at a rotational origin position of the inertial load 27 so as to face the inertial load, and detecting a swing width of the inertial load near the origin position O; Encoders 29, 30 arranged on shafts 23, 25
The stepping motor 24 rotates the driving pulley 21 forward and backward (rotational speed: 33 rpm) by a predetermined angle (for example, 45 °), and stops the inertial load 27 at the origin position. 28.

At this time, by confirming the stop origin position of the inertial load 27 based on the rotational displacement difference between the driving side encoder 29 and the driven side encoder 30, a deviation due to a temporal change of the test belt is confirmed, and the origin of the vibration displacement is confirmed. I try to determine the position.

In the residual vibration test, the pulleys 21 and 22 having 40 pulley teeth on the driving side and the driven side have two belt teeth.
A test belt having 78 teeth and a tooth width of 20 mm was subjected to an initial tension of 28.
At 0N, the operation time is 0.4 seconds (acceleration / deceleration time is 0.2
Second) and a stop time of 2.0 seconds.

In the bending resistance test, a test belt having 150 belt teeth and a belt tooth width of 20 mm was initially set on a pulley having 22 pulley teeth on the driving and driven sides using a biaxial testing machine. It is stretched with a tension of 280N and the rotation speed is 5500rpm.
, The breaking tension of the belt before the test, 2000 hours
The belt breaking tension after the belt running time of s and their residual strengths are shown in percentage (%).

[Comparison] The residual vibration time is 250.0 ms or less, the swing width is 0.008 ° or less, and the durability is 60 or less.
% Or more is an allowable range, and if it exceeds these, it is considered that the required responsiveness and durability are not satisfied. Sample N satisfying these responsiveness and durability at the same time
o4. That is, it is configured by bundling 6,600 filaments of 9 μm in diameter made of high-strength glass fiber.

FIG. 6 is a graph of the residual vibration time for each sample, in which the symbols (a) to (d) correspond to the samples No. 1 to No. 5, respectively.

In the bending resistance test, belt evaluation was performed using a pulley having 22 pulley teeth. However, since the minimum number of pulley teeth used for the conveyor belt shown in FIG. FIG. 7 shows the results of a bending durability test when a belt is stretched over such a pulley having the minimum number of teeth.

In FIG. 7, the vertical axis represents the residual strength of the belt,
The horizontal axis shows the number of times of repeated bending. The number of times of repeated bending is
It is represented by the number of belt teeth that passed a specific pulley tooth. This test is to confirm the degree of drop in residual strength due to the number of pulley teeth, and it is expected that the same result will be obtained even if the belt type is changed. The belt of sample No. 4, which was the best, was used as a test belt. In the figure, is 5 mm
5mm when stretched on a 20-pitch pulley with a pitch
5mm when stretched on a pulley with 22 teeth of pitch
The cases where the pulleys are stretched on pulleys having a pitch of 24 teeth are shown.

As shown in FIG. 7, the number of pulley teeth is 20 to 2
4, the remaining strength increases. this is,
This indicates that the bending fatigue decreases as the pulley diameter increases. Conversely, it shows that a belt configuration having a small degree of bending fatigue must be employed when using the pulley with a small number of pulley teeth, that is, a small pulley diameter.

However, the sample No. The belt of No. 4 does not drastically decrease according to the number of teeth. For example, the initial tension is about 20 k.
The residual strength from N is 2.0E + 07 (almost 2,000 hours).
rs. However, E is an index).
１３13 kN (60-65%), indicating that it can be used satisfactorily even with a pulley having a minimum diameter of 20 teeth. Therefore, the sample No. By using the belt of No. 4, sufficient durability can be ensured even when the size of the transport device is reduced.

From the above test results, the number of pulley teeth was 20 (5
Assuming a pulley of (mm pitch), it is necessary to use a high-strength glass fiber as a core wire material satisfying responsiveness and durability. The reason is as follows. That is, it is considered that the necessary elastic coefficient per belt width to improve the response is 65,000 kg / inch or more.
E glass fiber 9μ-3 / 8 (filament diameter 9μ, number of strands 3, number of small ropes) is 7400kg / m.
m ² (see Table 3). On the other hand, the configuration of the core wire for the required elastic modulus per inch of the belt width must satisfy the following expression (1).

Elastic coefficient required per belt width ≦ cross-sectional area per core wire × the number of theoretical driving lines × elastic coefficient of filament ····· (1) Here, elastic coefficient required per belt width: 65000
kg / inch, E glass fiber elastic modulus: 7400 kg / mm ² , cross-sectional area per core wire: 0.305528 mm ² [π (9
μ / 2) ² × 4800 lines] Theoretical driving number: 25.4 mm (1 inch) / (0.
93 mm + α) where 0.93 mm is a reference value obtained from a polynomial of the core wire diameter (y) and the number of filaments (x) shown in FIG.

FIG. 8 is a graph obtained by actually measuring the relationship between the 7 μm, 9 μm, and 11 μm core wires and the number of filaments, and calculating a polynomial from the measured values. The denominator α of the theoretical driving number is a gap required for the rubber flow, and specifically, 0.15 mm is substituted. The reason why the number of filaments of the cross-sectional area per core wire is 4,800 is that three filament bundles of 200 filaments per strand are twisted into a small rope and eight filaments are twisted.

The elastic modulus per inch of the belt width of the core wire made of E glass fiber is calculated from these values. The elastic modulus of the core wire per inch of the belt width = cross-sectional area per core wire × theoretical driving number × filament elasticity Coefficient = 0.30528 mm ² × [25.4 / (0.93 + 0.15)] × 7400 = 53130 That is, the elastic modulus per inch of the belt width of the core wire made of E glass fiber is 53130 kg / inch, which is the required elasticity. The coefficient cannot exceed 65,000 kg.

On the other hand, in the case of a high-strength glass fiber, the filament elastic modulus is 8700 kg kg / mm ^2.
3/11, 9μ-3 / 13, 7μ-3 / 15, 7μ-3
Of the / 18, the required elastic modulus is 65000 kg / inch or more except for 7 μ−3 / 15. Therefore, to obtain the desired response and durability, instead of E glass fiber,
It is preferred to use high strength glass fibers.

Table 4 shows the number of filaments, the elastic modulus of the material, the number of wires per inch, and the number of core wires 1 for each core wire configuration.
It shows the elastic modulus per book, the elastic modulus per inch, the minimum number of pulley teeth that can be used, and the pulley diameter. The elastic modulus per inch is obtained by the same formula as that for the E glass fiber.

[0045]

[Table 4]

[Relationship Between Pulley Pitch Diameter and Elastic Coefficient] Next, the relationship between the pulley pitch diameter and the elastic coefficient will be considered. The responsiveness increases as the elastic modulus of the core wire increases, but the core wire becomes thicker, so that the winding radius of the pulley becomes a problem. When a polynomial was created based on the actually measured values for the relationship between the pulley pitch diameter and the elastic coefficient in order not to reduce the responsiveness and durability, the graph in FIG. 9 was obtained.

That is, if the elastic coefficient required per belt width is set so as to satisfy the following equation (2) in accordance with the pulley diameter on which the belt is stretched, the elastic modulus can be used for the pulley pitch diameter to be used. The maximum standard elastic modulus can be obtained. Elastic coefficient required per belt width = -0.0544 x (pulley pitch diameter: mm) ² +39 7.45 x (pulley pitch diameter: mm) +61362 ... (2)

Since the maximum guide elastic modulus that can be used is merely a guide, it is necessary to manufacture a core wire configuration that meets the above elastic coefficient. Of course, because there is a possibility of production,
The tolerance of the elastic modulus obtained from the above formula is within ± 15%. In addition, when converting the pulley pitch diameter to the number of pulley teeth, the tolerance of the number of pulley teeth is set to ± 3 teeth, and an optimum combination is selected based on a combination within the above-mentioned tolerance.

Core cross-sectional area per required belt = inch required elastic modulus / 8700 (8700: elastic coefficient of U glass core material) Core cross-sectional area per theoretical belt per inch = filament per core (Diameter x filament cross-section x maximum number of shots) ・ Maximum number of shots (MAX SPI) = 25.4 /
(Core wire diameter + 0.15) The core wire configuration is determined by the above calculation formula, and the following formula (3) is satisfied. · Core elastic modulus per required inch of elastic belt ≤ elastic modulus per theoretical inch · · · · · · · · · (3) In this case, the filament diameter is determined by changing to 7μ, 9μ, and 11μ.

Next, the core configuration of the usable belt is determined from the pulley diameter. If the number of pulley teeth is 20 at a pitch of 5 mm, the core configuration of 9 μ−3 / 11 is obtained from the above equation (2). K = -0.0544 × 31.83 ² + 397.45 × 31.83 + 61362 = 74068 kg / inch

When 20 pieces of 9 μ-3 / 11 core wires are driven into a 1-inch wide belt, the elastic coefficient K1 is 73058.
kg / inch (= 20 pieces × 0.0000636 × 660
0 × 8700).

When the above elastic modulus is compared with K ≧ K1, a belt in which 20 cores of 9 μ−3 / 11 are driven into a 1-inch wide belt has a high responsiveness when used with a pulley having a pitch of 5 mm and 20 teeth. And the durability can be satisfied.

However, since ± 15% of the required maximum elastic modulus K per inch is within the range of use, it is actually 63000 to
An appropriate configuration may be selected between 85,000 kg / inch. Table 4 also shows the relationship between the elastic modulus, the minimum number of pulley teeth, and the minimum pitch diameter for samples Nos. 1 to 5.

From the above examination results, if the belt is a belt in which the core wire is embedded in the main body, and the material, diameter, and number of filaments constituting the core wire are set so as to satisfy the following equation (1), A belt having excellent responsiveness and durability can be obtained. Also, if the elastic coefficient required per belt width is set so as to satisfy the following expression (2) in accordance with the diameter of the pulley on which the belt is stretched, a belt having excellent responsiveness and durability can be obtained. Can be.

The elastic modulus required per belt width ≦ the cross-sectional area per core wire × the number of theoretical shots × the elastic modulus of the filament... (1) ・ The elastic modulus required per belt width = −0.0544 × (Pulley diameter) ² (mm) +397.45 x (Pulley diameter) +61362 (2)

It should be noted that the present invention is not limited to the above-described embodiment, and it goes without saying that many modifications and changes can be made within the scope of the present invention. For example, although the U-glass fiber filament is used in the above embodiment, it is a matter of course that other high-strength glass fibers may be used. Further, the residual vibration reduction belt is preferably applied to a timing belt having a toothed portion, but is applicable regardless of the presence or absence of the toothed portion. Further, by adhering the tooth cloth to the surface of the toothed portion, wear of the toothed portion due to contact with the pulley, generation of rubber powder, and the like can be prevented.

[0057]

As is apparent from the above description, according to the present invention, a core wire having a desired elastic modulus is buried by using a high-strength glass fiber filament, so that there is little residual vibration, and particularly high precision and high speed. Can be used in an apparatus that requires the above processing.

[Brief description of the drawings]

FIG. 1 is a perspective view of a general timing belt.

FIG. 2 is a perspective view of the same transport device.

FIG. 3 is an explanatory diagram showing belt responsiveness during conveyance.

FIG. 4 is a schematic plan view of a residual vibration measurement tester.

FIG. 5 is a schematic front view of the same.

FIG. 6 is a diagram showing a residual vibration measurement result.

FIG. 7 is a view showing bending resistance performance;

FIG. 8 is a graph for calculating a theoretical core diameter from the number of filaments.

FIG. 9 is a graph showing a relationship between an elastic coefficient and a pitch diameter.

[Explanation of symbols]

 2, 3 pulley 4, 5 belt 6 mounting table 7 work 11 main belt 12 toothed section 13 tooth cloth 14 core wire 17 weft 18 warp 20 residual vibration tester

Claims (3)

[Claims] 1. A residual vibration reducing belt in which a core wire is buried in a main body of a belt, wherein a material, a diameter, and a number of filaments constituting the core wire are set so as to satisfy the following expression (1). Elastic modulus required per belt width ≤ cross-sectional area per core wire x number of theoretical shots x elastic modulus of filament ... (1) 2. The residual vibration reduction belt according to claim 1, wherein an elastic coefficient required per belt width is set so as to satisfy the following expression (2) according to a diameter of a pulley on which the belt is stretched. Elastic coefficient required per belt width = -0.0544 x (pulley pitch diameter) ² (mm) +397.45 x (pulley pitch diameter) +61362 ... (2) 3. When the number of pulley teeth on which the belt is stretched is 20 and the minimum pulley diameter is 31.83 mm, 6600 filaments made of high-strength glass fiber and having a diameter of 9 μ are bundled as the core wire. The residual reduction belt according to claim 1, wherein the belt is used.