JP3577659B2 - Timing belt, transmission and injection molding machine - Google Patents

Description

[0001]
TECHNICAL FIELD OF THE INVENTION
The present invention relates to a timing belt for transmitting rotation of a drive timing pulley to a driven timing pulley, a transmission using the timing belt, and an injection molding machine using the transmission.
[0002]
[Prior 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 a screw mechanism for moving an injection device. And those provided between a screw mechanism of an ejector mechanism, an injection screw, and the like.
[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.
[0004]
However, when the teeth of the timing belt and the teeth of the timing pulley mesh with each other, air is compressed and meshed between them, and there is a disadvantage that noise is easily generated when the compressed air is ejected to the atmosphere.
By the way, in the case of a driving motor of several Kw to several tens of Kw, a timing belt having a width of 100 mm or more is required, and a considerably large noise is generated.
[0005]
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]
[Problems to be solved by the invention]
However, even if the sum of the widths of the 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 timing belt is wider than the wide timing belt. For some reason, there is a problem that the life is short.
When one narrow belt is damaged, the life of the new belt becomes extremely short if only the new timing belt is replaced with a new one. Therefore, all the timing belts are usually replaced.
[0007]
The present inventors have suggested that the above-mentioned cause is that even if the timing belts are exactly the same, the lengths may be slightly different, and when a plurality of timing belts having different lengths are used side by side, a short timing belt may be used. They found that the higher the load, the faster the damage.
[0008]
Meanwhile, the timing belt is generally manufactured by manufacturing a cylindrical primary product (sleeve) from a material such as rubber or cloth, and then cutting the cylindrical primary product 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 in the length dimension between the timing belts at both ends far apart from each other tends to be the largest. is there.
[0009]
SUMMARY OF THE INVENTION An object of the present invention is 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 power transmission device that can reduce the generation of noise and has a service life substantially the same as that of a conventional power transmission device, and an injection molding machine using the power transmission device.
[0010]
[Means for Solving the Problems]
In order to achieve the above object, an invention according to claim 1 is a timing belt manufactured by cutting a cylindrical primary product having a position mark indicating a position in a width direction on an outer surface into a plurality of narrow widths . The position mark has 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 .
[0011]
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, around the timing pulley and wind it around.
[0012]
Further, according to the above-described means , unlike when the position mark is a number such as “1”, “2”, “3”, etc., even when the width cut number of the cylindrical primary product is changed, It will be surely left on the belt.
[0013]
According to a second aspect of the invention, the gearing is a timing belt wound around a plurality of timing pulleys, a plurality of timing belts of claim 1 Symbol placement is made from the same tubular primary product, the cylindrical It is configured to be wound around the timing pulley in the order of primary products.
[0014]
According to this means, the generation of noise is reduced, and the difference in length between the timing belts is minimized, so that a load is evenly applied to each timing belt.
[0015]
In the above transmission, the timing belt a plurality of, it is preferable that wound around the timing pulley to match the position mark of each other (claim 3).
With this configuration, it is possible to easily confirm whether the arrangement order of the timing belts is correct after the teeth of the timing belts match each other accurately and the timing belts are wound around the timing pulleys.
[0016]
According to a fourth aspect of the present invention, the transmission device in which the timing belt is wound around the plurality of timing pulleys includes a drive motor, a screw mechanism for moving the pusher plate, a screw mechanism for the mold clamping device, and a screw mechanism for moving the injection device. In one or more injection molding machines provided between a screw mechanism of an ejector mechanism, an injection screw, and the like, the transmission device is a transmission device according to claim 2 or 3 .
[0017]
According to the above-described means, noise can be reduced, and the pusher plate, the mold clamping device, and the like can be smoothly operated for a long period by the drive motor.
[0018]
In the injection molding machine, the drive motor may be a servomotor (claim 5).
In this case, it is possible to accurately control the pusher plate, the mold clamping device, and the like.
[0019]
BEST MODE FOR CARRYING OUT THE INVENTION
Embodiments of the present invention will be described with reference to the accompanying drawings.
1 to 3, reference numeral 1 denotes 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 to a predetermined width, and has a tooth 1a on an inner surface and a tooth 1a on an outer surface. Have position marks ma, mb,...
[0020]
The cylindrical primary product T is manufactured by a material such as rubber or cloth through the same process as in the related 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 includes 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 mx of each timing belt 1 also includes the reference line s and the inclined line i.
[0021]
The position mark mx of each timing belt 1 indicates the order in which the timing belt 1 is arranged in the cylindrical primary product T by the distance of the inclined line i from the reference line s. Therefore, even when a plurality of the timing belts 1 manufactured by cutting the width of one cylindrical primary product T are changed in order and separated, 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 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.
[0022]
As shown in FIG. 2A, a symbol k or the like indicating the type of the tubular 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. In this way, it is possible to know from the symbol k whether or not the plurality of timing belts 1 have been cut from the same cylindrical primary product T.
[0023]
The plurality of (two in FIG. 1) timing belts 1 having the above-described configuration are arranged on the timing pulleys 2 and 3 in the order in which the cylindrical primary products T are arranged, and the teeth 1a of the timing belts 1 are provided on the timing pulleys 2 and 3. 2a and 3a are engaged with each other, and are wound so that their position marks ma and mb coincide with each other.
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 drive timing pulley 2 rotated by the drive motor 5 to the driven timing pulley 3 to rotate the rotary member 6.
[0024]
In the above description, a plurality of timing belts 1 can be wound around the timing pulleys 2 and 3 without matching the position marks mx to each other. However, when the position marks mx are matched, the teeth 1a and 1a of the timing belts 1 and 1 are set. However, even if there is an error, since the teeth 1a, 1a are linearly coincident with each other, power transmission loss is reduced.
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.
[0025]
In the transmission D, the air is easily released 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 servo motor 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.
[0026]
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. It is rotatably supported by the plate 17 and the rear plate 18, respectively.
[0027]
An injection screw 20 is rotatably attached to the pusher plate 11 and inserted into the heating cylinder 21. The heating cylinder 21 is fixed to the front plate 17.
[0028]
The structure of the injection device 22 mainly including the heating cylinder 21, the injection screw 20, the pusher plate 11, etc. (however, the transmission device D is excluded) is well-known, and the transmission device D is operated by operating the drive motor 5. When each ball screw shaft 14 is rotated in one direction through the pusher plate 11, the pusher plate 11 advances to the left in FIGS. 4 and 5 to push and move the injection screw 20, and the molten resin is heated from the heating cylinder 21 by the mold clamping device 24. The mold is injected into the molding cavities of the molds 25 and 26 which have been clamped.
[0029]
In this injection molding machine, the effect of the above-described transmission device D is generated as it is, noise is reduced, and a reduction in the life of the timing belt 1 is suppressed. Accordingly, the injection device 22 can be smoothly operated for many months, and maintenance can be facilitated.
[0030]
Explaining another structure of the injection molding machine shown in FIG. 4 (all are well known), a drive motor 28 is fixed to the pusher plate 11, and the drive motor 28 is provided between the drive motor 28 and the injection screw 20. A transmission 29 for transmitting rotation 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.
[0031]
The mold clamping device 24 movably supports a movable plate 40 to which the mold 25 is attached on a tie rod 39 integrally connecting a fixed plate 37 to which the mold 26 is attached and an end plate 38. A toggle mechanism 41 is provided between the board 40 and the end plate 38, and a crosshead 42 of the toggle mechanism 41 is moved by a screw mechanism 46 operated by a drive motor 44 via a transmission 45 to move the movable board 40. Is moved to close and open the mold.
[0032]
Further, the movable plate 40 is provided with an ejector mechanism 48. The ejector mechanism 48 is configured to move an ejector plate 53 having ejector pins 52 by a screw mechanism 51 which is operated via a transmission 50 by a drive motor 49.
[0033]
In such an electric injection molding machine, one or more of the transmissions 29, 34, 45, and 50 can be the transmission D shown in FIG. 1, and in such a case, the transmission for moving the pusher plate 11 is used. Device D can be a conventional transmission. The screw mechanisms 35, 46, and 51 convert the rotary motion into a linear motion, and, like the screw mechanism 12, include a ball screw shaft and a ball nut, and the ball nut moves by the rotation of the ball screw shaft. However, a structure in which the ball screw shaft moves by the rotation of the ball nut may be adopted. This point is the same in the screw mechanism 12. Each of the drive motors 5, 28, 33, 44, and 49 is an electric motor, and usually uses a servomotor.
[0034]
【The invention's effect】
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 from the position mark attached to the timing belt. It is easy to wind a plurality of timing belts around the timing pulley in the order in which the products are arranged.
Further, even if the number of width cuts of the cylindrical primary product is changed, the position mark is reliably attached to each timing belt.
[0035]
According to the second aspect of the present invention, the generation of noise is reduced, the driving noise becomes quiet, and the difference in length between the timing belts is minimized, so that the load is evenly applied to each timing belt. As a result, early damage to only one timing belt can be prevented, and there is an effect that the whole life is prolonged.
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. Further, after the timing belts are wound around, it is possible to easily confirm whether the arrangement order is correct.
[0036]
According to the fourth aspect of the present invention, it is possible to provide an injection molding machine that 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 servomotor, 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]
Reference Signs List 1 timing belt 2, 3 timing pulley 5, 28, 33, 44, 49 drive motor 11 pusher plate 24 mold clamping device 35, 46, 51 screw mechanism T cylindrical primary product c cutting line D, 29, 34, 45, 50 , Transmission i slope line m, ma, mb, mx position mark s reference line

Claims (5)

In a timing belt manufactured by cutting a cylindrical primary product having a position mark indicating a position in the width direction on the outer surface into a plurality of narrow widths ,
The timing belt according to claim 1, wherein the position mark includes 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 . In a transmission in which a timing belt is wound around a plurality of timing pulleys,
2. The transmission according to claim 1, wherein the plurality of timing belts manufactured from the same cylindrical primary product are wound around a timing pulley in the order of arrangement of the cylindrical primary product . 3. The transmission according to claim 2, wherein the plurality of timing belts are wound around the timing pulley such that their position marks match each other . A transmission in which a timing belt is wound around a plurality of timing pulleys is a drive motor, a screw mechanism for moving the pusher plate, a screw mechanism for the mold clamping device, a screw mechanism for moving the injection device, a screw mechanism for the ejector mechanism, and injection. In one or more injection molding machines provided between screws and the like,
An injection molding machine , wherein the transmission is the transmission according to claim 2 . The injection molding machine according to claim 4, wherein the drive motor is a servomotor .

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