JP2000097288A - Timing belt, transmission and injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To lengthen longevity of a timing belt after reducing noise. SOLUTION: A timing belt 1 is manufactured by cutting a cylindrical first product on an outer surface of which a positional mark to show a position in the cross direction is attached into round slices in specified width, and it is wound around timing pulleys 2, 3 in order of the cylindrical first product by matching the positional marks ma, mb with each other. As an error of length dimensions of the timing belts 1, 1 becomes the lowest limit, a load is uniformly applied on each of the timing belts 1, and lowering of longevity of the timing belts 1 is prevented. Additionally, it becomes easier for air to escape out from a clearance between the timing belts 1, 1 before it is compressed between the timing belts 1 and the timing pulleys 2, 3, and noise is reduced accordingly.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a timing belt for transmitting rotation of a drive timing pulley to a driven timing pulley, a transmission device using the timing belt, and an injection molding machine using the transmission device.

[0002]

2. Description of the Related Art As an electric injection molding machine, a transmission device in which a timing belt is wound around a plurality of timing pulleys includes, for example, a drive motor, a screw mechanism for moving a pusher plate, a screw mechanism for a mold clamping device, and an injection device. A mechanism provided between a screw mechanism for moving a screw, a screw mechanism of an ejector mechanism, an injection screw, and the like is known.

[0003] Unlike the V-belt and the flat belt, the above-described transmission in which a timing belt is wound around a plurality of timing pulleys has teeth formed on each of the timing belt and the timing pulley and does not slip. Has the advantage of communicating accurately.

However, when the teeth of the timing belt and the teeth of the timing pulley mesh with each other, air is compressed and caught between them, and there is a disadvantage that noise is easily generated when the compressed air is ejected to the atmosphere. By the way, several Kw to several tens K
In the case of the drive motor of w, a timing belt having a width of 100 mm or more is required, and considerably large noise is generated.

Therefore, as a countermeasure, a plurality of narrow timing belts are arranged side by side and wound around a timing pulley. With this configuration, the air escapes from the gap between the plurality of timing belts, so that the amount of air compressed between the teeth is reduced, and the generation of noise is reduced.

[0006]

However, even if the sum of the widths of a plurality of narrow timing belts is the same as the width of one wide timing belt, and the transmission power is the same, the narrow width of the narrow timing belt is small. There is a problem that the life of the timing belt is shorter than that of the wide timing belt. In the case where one narrow belt is damaged, if only the new timing belt is replaced with a new one, the life of the new belt becomes extremely short, so that all the timing belts are usually replaced.

[0007] The present inventors have proposed that the above-mentioned causes may be slightly different in length even if the timing belts are exactly the same, and when a plurality of timing belts having different lengths are used side by side, They found that the shorter the timing belt, the higher the load and the earlier the damage.

By the way, a timing belt is generally
A cylindrical primary product (sleeve) is manufactured from a material such as rubber or cloth, and then the cylindrical primary product is cut to a predetermined width. For this reason, when the number of width cuts of the cylindrical primary product is two or more (the number of timing belts is three) or more, the error of the length dimension between the timing belts at both ends far apart from each other tends to be the largest. is there.

SUMMARY OF THE INVENTION It is an object of the present invention to provide a timing belt which can be easily wound around a plurality of timing pulleys in the order of arrangement of a cylindrical primary product. Another object of the present invention is to provide a transmission device that can reduce the generation of noise and that has a service life substantially the same as that of a conventional transmission device, and an injection molding machine using the transmission device.

[0010]

In order to achieve the above-mentioned object, according to the present invention, a plurality of cylindrical primary products each having a position mark indicating a position in a width direction attached to an outer surface thereof are provided in a plurality of narrow widths. The width was cut and manufactured.

In this means, the position of each timing belt at the time of cutting the width of the cylindrical primary product is known from the position mark attached to the timing belt. Therefore, it is easy to arrange the timing belts adjacent to each other, which has the smallest error in the length dimension, on the timing pulley and wind it around the timing pulley.

In the above-mentioned timing belt, the position mark may have a reference line crossing a cutting line for cutting the width of the cylindrical primary product, and an inclined line inclined with respect to the reference line. Is preferable (claim 2). In this configuration, unlike when the position mark is, for example, a number such as “1”, “2”, or “3”, even when the number of width cuts of the cylindrical primary product is changed, each timing belt is securely attached. Will be left behind.

According to a third aspect of the present invention, there is provided a transmission in which a timing belt is wound around a plurality of timing pulleys, wherein the plurality of timing belts are manufactured from the same cylindrical primary product. , And wound around the timing pulley in the order of arrangement of the cylindrical primary product.

According to this means, the generation of noise is reduced, and the difference in length between the timing belts is suppressed to the minimum, so that a load is evenly applied to each timing belt.

In the above-mentioned transmission, it is preferable that a plurality of timing belts are wound around the timing pulley so that their position marks coincide with each other. With this configuration, it is possible to easily check whether the timing belts are arranged in the correct sequence after the timing belts are wound around the timing pulleys while the teeth of the timing belts are exactly coincident with each other.

According to a fifth aspect of the present invention, a transmission device in which a timing belt is wound around a plurality of timing pulleys moves a drive motor, a screw mechanism for moving a pusher plate, a screw mechanism for a mold clamping device, and an injection device. In one or more injection molding machines provided between a screw mechanism to be driven, a screw mechanism of an ejector mechanism, an injection screw, and the like, the transmission device is a transmission device according to claim 3 or 4.

According to the above means, noise can be reduced, and the pusher plate, the mold clamping device, and the like can be smoothly operated over a long period by the drive motor.

In the above injection molding machine, the drive motor can be a servomotor. In this case, the pusher plate, the mold clamping device, and the like can be accurately controlled.

[0019]

Embodiments of the present invention will be described with reference to the accompanying drawings. In FIG. 1 to FIG.
Is a timing belt. The timing belt 1 is manufactured by cutting a cylindrical primary product T having a position mark m indicating a position in the width direction on an outer surface thereof into a predetermined width,
It has teeth 1a on its inner surface and position marks m on its outer surface.
a, mb,...

The cylindrical primary product T is manufactured by a material such as rubber or cloth through the same steps as in the prior art. The position marks ma, mb,... Of the timing belts 1 are not the same but different from each other. The position mark m of the cylindrical primary product T is a reference line s orthogonal to the cutting line c of the cylindrical primary product T.
And an inclined line i inclined with respect to the reference line s. Therefore, the position mark m of each timing belt 1
x also consists of a reference line s and a slope line i.

The position mark mx of each timing belt 1
Displays the arrangement order of the timing belt 1 on the cylindrical primary product T by the distance of the inclined line i from the reference line s. Therefore, even when a plurality of timing belts 1 manufactured by cutting the width of one cylindrical primary product T are separated from each other by changing the order, the timing belts 1 can be correctly arranged according to the order of the cylindrical primary product T. it can. The position mark mx may be a number other than the figure, for example, a number such as “1”, “2”, or “3”, or a character or a symbol such as “A”, “B”, or “C”. If the number of width cuts of the primary product T changes, the position in the width direction may not be displayed correctly.

As shown in FIG. 2A, a symbol k or the like indicating the type of the cylindrical primary product T may be inserted into one or both of the reference line s and the inclined line i of the position mark mx. is there. In this way, it is possible to know from the symbol k whether or not a plurality of timing belts 1 are cut from the same cylindrical primary product T.

A plurality (2 in FIG. 1) having the above configuration
The timing belt 1 of the present invention meshes with the timing pulleys 2 and 3 in the order of arrangement of the cylindrical primary product T, the teeth 1a of the timing belt 1 mesh with the teeth 2a and 3a of the timing pulleys 2 and 3, and the position mark ma of each other. , Mb are matched. As described above, the timing belts 1 and 1 and the timing pulleys 2 and 3 constitute a transmission device D, which transmits the rotation of the driving timing pulley 2 rotated by the driving motor 5 to the driven timing pulley 3 to rotate the rotating member 6.

In the above, a plurality of timing belts 1 can be wound around the timing pulleys 2 and 3 without matching the position marks mx with each other. 1
Even if there is an error in a, 1a, since the teeth 1a, 1a are linearly coincident, power transmission loss is reduced. Further, after the plurality of timing belts 1 are wound around the timing pulleys 2 and 3, it is possible to know at a glance whether or not the arrangement order of the timing belts 1 is correct.

In the transmission D, the air can easily escape from the gap between the timing belts 1 and 1 before the air is compressed between the timing belt 1 and the timing pulleys 2 and 3, and the noise is reduced accordingly. . Further, since the difference between the lengths of the timing belts 1 is minimized, the load is evenly applied to the timing belts 1 and the life of the timing belts 1 is prevented from being shortened. As the drive motor 5, an electric motor such as a servomotor or a hydraulic motor, or a prime mover such as an internal combustion engine in some cases, is used. The number of timing belts 1 used can be three or more.

FIGS. 4 and 5 show an electric injection molding machine in which the above-mentioned transmission device D is also provided between the drive motor 5 and the screw mechanisms 12 for moving the pusher plate 11. The pusher plate 11 is screwed with ball nuts 15 and 15 on ball screw shafts 14 and 14 of screw mechanisms 12 and 12 for changing the rotary motion into linear motion, respectively. It is movably supported. The timing pulley 3 of the transmission D is mounted on each of ball screw shafts 14 and 14 (corresponding to the rotating member 6 in FIG. 1), and each of the ball screw shafts 14 is integrally connected to each other by a guide rod 16. Plate 17
And the rear plate 18 rotatably supported.

An injection screw 20 is rotatably mounted on the pusher plate 11 and inserted into a heating cylinder 21. The heating cylinder 21 is fixed to the front plate 17.

The structure of the injection device 22 mainly including the heating cylinder 21, the injection screw 20, the pusher plate 11, and the like (excluding the transmission device D) is well known. When each ball screw shaft 14 is rotated in one direction via the transmission D, the pusher plate 11 moves forward to the left in FIGS.
0 to move the molten resin from the heating cylinder 21 to the mold clamping device 2.
4 injects into the molding cavities of the molds 25 and 26 clamped by the mold.

In this injection molding machine, the effect of the transmission device D described above is produced as it is, noise is reduced, and a reduction in the life of the timing belt 1 is suppressed. Therefore, the injection device 22 can be operated smoothly for many months, and maintenance becomes easy.

Referring to another structure of the injection molding machine shown in FIG. 4 (all of which are well known), a drive motor 28 is fixed to the pusher plate 11, and a drive motor is provided between the drive motor 28 and the injection screw 20. A transmission 29 for transmitting the rotation of the motor 28 to the injection screw 20 is provided. The injection device 22 is movably supported by a guide rod 32 of a base 31 and is moved back and forth by a screw mechanism 35 operated by a drive motor (electric motor) 33 via a transmission device 34. ing.

The mold clamping device 24 includes a movable platen 4 having a mold 25 attached to a tie rod 39 integrally connecting a fixed plate 37 to which the mold 26 is attached and an end plate 38.
0 is movably supported, a toggle mechanism 41 is provided between the movable platen 40 and the end plate 38, and the crosshead 42 of the toggle mechanism 41 is
The movable platen 40 is moved by a screw mechanism 46 which is operated via a transmission 45 by means of the movable plate 40 to move the mold clamping and mold opening.

The movable plate 40 has an ejector mechanism 4
8 are provided. The ejector mechanism 48 is configured to move an ejector plate 53 having ejector pins 52 by a screw mechanism 51 that is operated via a transmission 50 by a drive motor 49.

In such an electric injection molding machine, one or more of the transmissions 29, 34, 45, 50 can be the transmission D shown in FIG. 1, and in such a case, the pusher plate 11 can be used. Can be a conventional transmission. In addition, screw mechanism 35,4
Numerals 6 and 51 convert the rotary motion into a linear motion, and are composed of a ball screw shaft and a ball nut as in the screw mechanism 12, and the ball nut is moved by the rotation of the ball screw shaft. A structure in which the ball screw shaft is moved by the rotation of. This point is screw mechanism 1
The same applies to 2. Drive motors 5, 28, 33,
Reference numerals 44 and 49 denote electric motors, and usually use a servomotor.

[0034]

As described above, according to the first aspect of the invention, the position of each timing belt when the width of the cylindrical primary product is cut can be known by the position mark attached to the timing belt. Therefore, it is easy to wind a plurality of timing belts around the timing pulley in the order of arrangement of the cylindrical primary product. In this timing belt, when the position mark is constituted by a reference line intersecting a cutting line of the width cutting of the cylindrical primary product and an inclined line inclined with respect to the reference line, the width cutting of the cylindrical primary product is achieved. Even if the number is changed, a position mark is reliably attached to each timing belt.

According to the third aspect of the present invention, the generation of noise is reduced and the driving sound becomes quiet, and the difference in length between the timing belts is suppressed to the minimum, so that the timing belts are evenly distributed. Load is increased,
Premature damage to only the timing belt is prevented, and the overall life is extended. In this transmission, when a plurality of timing belts are wound around timing pulleys with their position marks coincident with each other, the teeth of each timing belt coincide exactly with each other, so that the transmission loss is reduced and the timing belt is further reduced. Long life. After the timing belts are wound around, it is possible to easily confirm whether the arrangement order is correct.

According to the fifth aspect of the present invention, it is possible to provide an injection molding machine which is quiet in operation noise, has a long life of the transmission device, and is easy to maintain. In this injection molding machine, when the drive motor is a servo motor,
It is possible to accurately control an injection device, a mold clamping device, and the like using the transmission of the present invention.

[Brief description of the drawings]

FIG. 1 is a diagram showing an embodiment of a transmission according to the present invention.

FIG. 2 is an external view showing an example of a cylindrical primary product.

FIG. 3 is a diagram illustrating a state in which a timing belt is wound around a timing pulley.

FIG. 4 is a view showing an embodiment of an electric injection molding machine according to the present invention.

FIG. 5 is a sectional view of a main part of the injection molding machine of FIG.

[Explanation of symbols]

1 Timing belt 2, 3
Timing pulley 5, 28, 33, 44, 49 Drive motor 11 Pusher plate 24 Mold clamping device 35, 4
6,51 Screw mechanism T Cylindrical primary product c Cutting line D, 29, 34, 45, 50, transmission i Inclination line m, ma, mb, mx Position mark s Reference line

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI Theme coat ゛ (Reference) F16H 7/02 F16H 7/02 A

Claims (6)

[Claims] 1. A timing belt which is manufactured by cutting a plurality of narrow primary width products of a cylindrical primary product having a position mark indicating a position in a width direction on an outer surface. 2. The position mark according to claim 1, further comprising: a reference line intersecting a cutting line for cutting the width of the cylindrical primary product, and an inclined line inclined with respect to the reference line. The described timing belt. 3. A transmission device in which a timing belt is wound around a plurality of timing pulleys, wherein the plurality of timing belts according to claim 1 or 2 manufactured from the same cylindrical primary product are used as the cylindrical primary product. A transmission that is wound around the timing pulley in the order in which the transmission is arranged. 4. The transmission according to claim 3, wherein the plurality of timing belts are wound around the timing pulley such that their position marks match each other. 5. A transmission device in which a timing belt is wound around a plurality of timing pulleys, a drive motor, a screw mechanism for moving a pusher plate, a screw mechanism for a mold clamping device, a screw mechanism for moving an injection device, and an ejector mechanism. 5. An injection molding machine provided in one or more of a screw mechanism, an injection screw, and the like, wherein the transmission device is the transmission device according to claim 3 or 4. 6. The injection molding machine according to claim 5, wherein the drive motor is a servo motor.