JP5653784B2 - Silent injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine, and more particularly to an injection molding machine that reduces noise generated from a contact portion between a pulley and a timing belt and is excellent in quietness.

<Injection molding machine drive>
A drive device for an injection molding machine will be described with reference to FIGS. The injection molding machine includes a plurality of driving devices. FIGS. 1 and 2 illustrate a driving device 1 that drives a toggle head (not shown) attached to the holding plate 2 as one of the plurality of driving devices. The driving force of the motor 3 as a driving source is transmitted to a mechanism such as a ball screw via the driving pulley 12, the driven pulley 4, the timing belt 5, and the like. The motor 3 is fixed to the motor bracket 6.
A driving pulley 12 is fixed to the end of the motor shaft 14 (see FIG. 2) by a pulley nut 9. Pulley flanges 15 are provided on both sides of the drive pulley 12 so that the timing belt 5 does not come off. An inner ring of a bearing (bearing) 10 is fixed to an end 11 of the drive pulley located on the opposite side of the motor 3 with respect to the timing belt 5, an outer ring of the bearing 10 is fixed to the bearing holder 8a, and the drive pulley 12 is The bearing 10 is rotatably supported with respect to the bearing holder 8a. The bearing holder 8a is fixed to the wall member 7a by bolts (not shown).

  As an advantage of using the driving pulley 12, the driven pulley 4 and the timing belt 5 for the driving force transmission unit, the motor 3 as a driving source can be arranged beside the mechanism unit. As a result, the overall length of the machine can be shortened, and the reduction ratio of the driving side and driven side pulleys 12 and 4 can be set arbitrarily, so that the degree of freedom in determining the output conditions of the driving device 1 is high. Etc.

However, when the driving pulley 12, the driven pulley 4 and the timing belt 5 are used for the driving force transmission unit, the driving pulley 12 and the driven pulley 4 are pulled in the tangential direction with the timing belt 5 by the tension of the timing belt 5, The motor shaft 14 to which the pulley 12 is fixed bends to the driven pulley 4 side. When the deflection of the motor shaft 14 is large, an excessive load is applied to a bearing (not shown) that supports the motor shaft 14 in the components of the motor 3, and the bearing may be damaged.
Therefore, in order to prevent the deflection of the motor shaft 14, there is a method in which the end 11 of the drive pulley or the end of the motor shaft 14 is supported by the bearing 10 and the outer ring of the bearing 10 is fixed to the bearing holder 8a. It may be adopted (see FIGS. 1 and 2).
Further, the driving pulley 12, the driven pulley 4 and the timing belt 5 rotate each time the injection molding machine repeats the mold clamping mold opening operation, so that the driving pulley 12, the driven pulley 4 and the timing belt 5 are brought into contact with each other. Noise is generated, and depending on the operating conditions of the machine, there is a problem that it reaches a noise level that is annoying to surrounding workers.

<Injection molding machine noise>
The noise generated from the injection molding machine will be described. In the driving device 1 in which the pulleys 4 and 12 and the timing belt 5 are used for the driving force transmission unit and the driving pulley 12 is fixed to the motor shaft 14, the driving force is the friction between the pulleys 4 and 12 and the timing belt 5, or If it is a toothed belt, it is transmitted by meshing teeth, but noise is generated by impact each time the pulleys 4, 12 and the timing belt 5 come in contact, and air vibration is generated by compression of air at the contact portion. Generates noise.
When the diameter of the drive pulley 12 is smaller than the diameter of the driven pulley 4, that is, when the reduction ratio is increased, the length of meshing between the pulleys 4, 12 and the timing belt 5 is shorter on the drive pulley 12 side. In the case of a pressing force applied per unit length or a toothed belt, the force applied per tooth is large, and the noise on the side of the drive pulley 12 having a smaller diameter increases. Since noises from the pulleys 4 and 12 and the timing belt 5 are mainly generated from their contact portions, as a conventional means for solving the noise problem, the driving pulley 12 and the driven pulley 4 are covered so as not to be exposed to the outside. The method is taken.
Under normal operating conditions of an injection molding machine, these noises have a frequency distribution in the range of several tens to several thousand Hz, and a sound of about 20 to about 3000 Hz, which is a low to mid frequency range that is difficult to be silenced by sheet metal. included.

  Generally, there are a method of covering with a sheet metal soundproof cover, a method of covering with a cast member, and a method of covering with a composite soundproof cover using a resin material. Furthermore, a sound absorbing material, a sound insulating material, a vibration damping material, or the like may be attached to the inside of the cover to make a double structure cover to improve the soundproofing performance.

The noise in the high frequency band can be silenced to some extent by covering the source with a sheet metal member, but the noise in the middle and low frequency band is less likely to be silenced because it easily passes through the sheet metal. In order to silence noise in all frequency bands including the mid-low range, it is preferable to use a highly rigid member with a high sound insulation effect and a large mass per unit area. In particular, cast iron material deposits graphite grains inside, and the sound is reflected and attenuated at the interface between the steel and the graphite grains, so that it has not only a sound insulation effect but also a sound absorption effect, and a high noise prevention effect. Alternatively, a high sound insulation effect can be obtained even with highly rigid rolled steel.
There are the following conventional techniques related to the soundproofing technology of injection molding machines.
In Patent Document 1, when the two pulleys of the driving pulley and the driven pulley and the timing belt are covered with a soundproof cover so as not to be exposed to the outside, a mold clamping mechanism portion, an injection mechanism portion, a metering mechanism portion constituting an injection molding machine, A technique is disclosed in which the pulleys and timing belts of at least the former three mechanism parts are simultaneously covered with a soundproof cover with respect to the four mechanism parts of the protrusion mechanism part.
Patent Document 2 discloses a technique for arranging pulleys and timing belts used in a metering mechanism section inside hollow annular structures formed by inner and outer casting members.
In Patent Document 3, in a structure in which a driving pulley and a driven pulley are arranged on the back surface of a casting member, a recess is formed so that the casting member covers the periphery of the two pulleys and the timing belt, and the opening is covered. Thus, a technique for forming a cast soundproof cover has been disclosed.
Patent Document 4 discloses a technique for storing a drive source such as a motor and a drive pulley inside the machine base.
In Patent Document 5, in a soundproof cover having a fixing flange portion at an outer edge portion, the structure is a double structure, the outside is formed of a hard resin, the inside is formed of a soft resin or rubber, A technique for enhancing the sound insulation effect by disposing the gaps therebetween is disclosed.

JP 2006-21338 A JP 2000-190361 A JP 2006-150597 A JP 2000-117772 A JP-A-9-151788

The prior art described in the background art has the following problems.
(Problem 1)
Since noise with a frequency in the low midrange is likely to pass through the sheet metal, the conventional technology using the soundproof cover made of sheet metal has a small effect of noise reduction on the noise with the frequency in the low midrange. Conventionally, when the driving pulley and the driven pulley are respectively covered, two soundproof covers are required, and the number of parts is increased. When the two pulleys on the driving side and the driven side are covered with one soundproof cover, the soundproof cover is large. Become heavier. In addition, heat generated from the motor, which is the drive source, is transferred to the drive pulley through the motor shaft, and if the drive pulley is covered with the soundproof cover, the heat cannot be dissipated and the temperature inside the soundproof cover rises and the timing belt Reduce lifespan.
(Problem 2)
The conventional technique of covering the driving pulley and the driven pulley with the casting has a large sound insulation effect, but increases the weight of the material and increases the cost. Similarly to the problem 1, the life of the timing belt is reduced by the increase of the internal temperature.
(Problem 3)
In the conventional technology in which the drive source and the drive pulley are arranged inside the machine base, the arrangement place of the drive device is limited, so that the design restrictions are large and the maintenance work is difficult.
(Problem 4)
The conventional technology for producing a soundproof cover with a resin composite material is easy to transmit noise with a single resin alone and has a low noise reduction effect. turn into.
As described above, the soundproofing cover made of sheet metal has a small sound insulation effect, the technology of covering with a cast member increases the cost, the technology of storing inside the machine base decreases the degree of design freedom, and the resin composite material Soundproof covers are expensive.

  In view of the above-described problems of the prior art, an object of the present invention is to provide an injection molding machine that reduces noise generated from a contact portion between a pulley and a timing belt and is excellent in silence.

According to the first aspect of the present invention, a pulley and a timing belt are used as a driving force transmission unit, a motor as a driving source is fixed to a motor bracket, a driving pulley is fixed to a motor shaft, and the end of the driving pulley is fixed. Or the end of the motor shaft is rotatably supported by a bearing and the outer ring of the bearing is supported by a bearing holder so that the periphery of the driving pulley is covered between the motor bracket and the bearing holder. An injection molding machine characterized in that a wall member is provided or a bearing holder is provided on the motor bracket so as to cover the periphery of the drive pulley.
A second aspect of the present invention is the injection molding machine according to the first aspect, wherein the wall-like member is formed integrally with the motor bracket.
A third aspect of the present invention is the injection molding machine according to the first aspect, wherein the bearing holder is formed integrally with the motor bracket.
According to a fourth aspect of the present invention, the timing belt and the driven pulley exposed to the outside are covered with a soundproof cover, and the soundproof cover is connected to the motor bracket. The injection molding machine described in 1.
The invention according to claim 5 is the injection molding machine according to any one of claims 1 to 4, wherein a through hole smaller than the outer diameter of the bearing is formed in a central portion of the bearing holder. is there.

  According to the present invention, it is possible to provide an injection molding machine that reduces noise generated from a contact portion between a pulley and a timing belt and is excellent in silence.

It is a figure explaining the conventional structure which supported the drive pulley end part using the bearing holder. It is AA sectional drawing of FIG. 1 of the drive pulley support part shown in FIG. It is a figure explaining the 1st Embodiment of this invention which provided the wall-shaped member so that the circumference | surroundings of a drive pulley might be covered between a motor bracket and a bearing holder. It is a figure explaining the 2nd Embodiment of this invention in which the wall-shaped member shown in FIG. 3 was integrally formed in the motor bracket. It is a figure explaining embodiment which covers the drive pulley side with the structure which has the high sound-insulation effect with respect to the noise of all frequencies, and also covers the driven pulley side with a soundproof cover. FIG. 6 is an enlarged view of a drive pulley support portion shown in FIG. 5. FIG. 7 is a cross-sectional view of the drive pulley support portion shown in FIG. It is a right perspective view explaining the 3rd Embodiment of this invention. It is a left perspective view explaining the 3rd Embodiment of this invention. It is an enlarged view of the drive pulley support part of the 4th Embodiment of this invention. It is CC sectional drawing of FIG. 10 of the drive pulley support part of embodiment of this invention. It is an enlarged view of the soundproof cover connection part when covering with the soundproof cover of the embodiment of the present invention. It is an enlarged view of the soundproof cover connection part in the case of abutting the soundproof cover of embodiment of this invention. It is a figure explaining the soundproof cover fixing method in the case of fixing the soundproof cover of embodiment of this invention to a holding plate. It is a figure explaining the fixing method of the soundproof cover back side in the case of using the stay and adjustment cover of embodiment of this invention. It is a figure explaining the soundproof cover connection part back side when not using the stay and adjustment cover of the embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the same or similar components as those in the related art will be described using the same reference numerals.
FIG. 3 is a view for explaining a first embodiment of the present invention in which a wall-like member is provided between the motor bracket and the bearing holder so as to cover the periphery of the drive pulley. A driving pulley 12 (see FIG. 7), a driven pulley 4 and a timing belt 5 are used as a driving force transmission unit, and a motor 3 as a driving source is fixed to a motor bracket 6 and an end of the driving pulley 12 or a motor shaft 14 ( In the driving device 1 in which the end portion of the bearing 10 is rotatably supported by the bearing 10 and the outer ring of the bearing 10 is supported by the bearing holder 8b, the motor bracket 6, the bearing holder 8b, and the wall-like member 7b disposed therebetween. Are required to be strong and rigid enough to support the moment load applied to the motor 3, the bearing 10 and the motor shaft 14, respectively. Combined with a high sound insulation effect. The wall-like member 7b is provided so as to cover the drive pulley 12 (see FIG. 7) while arranging a slit 70 for releasing the timing belt 5 between the motor bracket 6 and the bearing holder 8b. Except for the wall member 7b and the bearing holder 8b, the configuration is the same as that shown in FIGS.

  In the configuration of the first embodiment of the present invention, using the combination of the motor bracket 6, the wall-like member 7a and the bearing holder 8a (see FIGS. 1 and 2) used in the conventional driving device 1, The combination of the motor bracket 6, the wall member 7b, and the bearing holder 8b covers the drive pulley 12 side, which is relatively noisy, so that the number of parts is not increased and the cost is not increased as compared with the prior art. Noise from the drive pulley 12 can be reduced. The structure that covers the drive pulley 12 can enhance the noise prevention effect by using a structure that has a high sound insulation effect against noise of any frequency.

Further, since the vicinity of the drive pulley 12 is covered by the motor bracket 6, the bearing holder 8b, and the wall-like member 7b disposed therebetween, the structure can be made more compact than the conventional soundproof cover. Further, since the deflection of the motor shaft 14 due to the tension of the timing belt 5 is prevented, the inclination of the drive pulley 12 is suppressed, and the friction between the pulley flange 15 (see FIG. 7) and the side of the timing belt 5 hardly occurs. Noise is further reduced.
If the bearing holder 8b is fixed to the end face of the wall-like member 7b with the bearing holder fixing bolt 13 (see FIG. 7), the timing belt 5 can be removed, and the assembly and maintenance can be facilitated. . In this embodiment, it is desirable that the wall-like member 7b is integrated with the motor bracket 6 and made of a casting.

FIG. 4 is a view for explaining a second embodiment in which the wall-like member shown in FIG. 3 is formed integrally with the motor bracket. In the second embodiment, the number of parts can be reduced by using a member in which the motor bracket 6 and the wall member 7b are integrally formed. Alternatively, the three elements of the motor bracket 6, the bearing holder 8b, and the wall member 7b may be formed as an integrally formed member. Thus, the number of parts can be reduced by using a plurality of elements as an integrally formed member.
If the bearing holder 8b is fixed to the end face of the wall-like member 7b with the bearing holder fixing bolt 13, the timing belt 5 can be detached from the drive pulley 12 and the structure is easy to assemble and maintain. In this embodiment, it is desirable that the wall-like member 7b is integrated with the motor bracket 6 and made of a casting.

  FIG. 5 is a view for explaining an embodiment in which the drive pulley 12 side is covered with a structure having a high sound insulation effect against noises of all frequencies, and the driven pulley 4 side is covered with a soundproof cover. FIG. 6 is an enlarged view of the drive pulley support shown in FIG. FIG. 7 is a cross-sectional view of the drive pulley support shown in FIG. As shown in FIG. 7, the end 11 of the drive pulley is supported by a bearing 10, and the outer ring of the bearing 10 is fixed by a bearing holder 8b. If the bearing holder 8b is fixed to the end face of the wall-like member 7b with the bearing holder fixing bolts 13, the timing belt 5 can be removed and the structure is easy to assemble and maintain. In this embodiment, it is desirable that the wall-like member 7b is integrated with the motor bracket 6 and made of a casting. The wall member 7b and the bearing holder 8b may be integrated and fixed to the motor bracket 6, or the motor bracket 6, the bearing holder 8b, and the wall member 7b may be integrated.

  Covering the drive pulley 12 side with a structure having a high sound insulation effect against noises of all frequencies, and further covering the driven pulley 4 side with a soundproof cover 16, a higher soundproofing effect than with a conventional sheet metal soundproof cover alone. Can be obtained. In this way, the embodiment of the present invention is less expensive than the conventional method of covering the entire periphery of the drive pulley 12 and the timing belt 5 with a cast member or the method of covering the soundproof cover 16 having a complicated shape made of resin. Can be suppressed.

  In the embodiment of the present invention, a combination of the motor bracket 6 and the bearing holder 8a used in the conventional driving device 1 and the wall member 7a disposed therebetween is used in the embodiment of the present invention. Since the vicinity of the drive pulley 12 is covered by the combined configuration of the holder 8b and the wall-like member 7b disposed between the holder 8b, the structure of the conventional soundproof cover can be made more compact, and the portion of the conventional soundproof cover on the side of the drive pulley 12 can be formed. The soundproof cover 16 used in the embodiment of the present invention can be used.

  The heat transmitted from the motor 3 to the motor shaft 14 and the frictional heat between the drive pulley 12 and the timing belt 5 increase the ambient temperature inside the soundproof cover 16 and cause the life of the timing belt 5 to decrease. However, in the embodiment of the present invention, heat is transferred from the end of the drive pulley 12 or the end of the motor shaft 14 to the bearing holder 8b via the bearing 10 and is radiated to the outside. An increase in the atmospheric temperature in the soundproof cover 16 can be suppressed, and a decrease in the life of the timing belt can be suppressed. Further, since the deflection of the motor shaft 14 due to the tension of the timing belt 5 is prevented, the inclination of the drive pulley 12 is suppressed, and the pulley flange 15 (see FIG. 7) and the side surface of the timing belt 5 are less likely to be worn, resulting in noise. Reduce more.

FIG. 8 is a right perspective view for explaining the third embodiment of the present invention. FIG. 9 is a left perspective view for explaining a third embodiment of the present invention.
FIG. 10 is an enlarged view of the drive pulley support portion of the fourth embodiment of the present invention. FIG. 11 is a cross-sectional view of the drive pulley support portion of the fourth embodiment of the present invention.

When the pulley nut 9 (see FIGS. 10 and 11) is long and protrudes from the end 11 of the drive pulley, the pulley nut 9 can be released by providing the through hole 72 at the center of the bearing holder 8c. Thereby, the bearing holder 8c only needs to secure a thickness that can fix the outer ring of the bearing 10, and the bearing holder 8c can be made thin.
Further, since the end 11 of the drive pulley is exposed from the through hole 72, it is easy to radiate the heat generated from the motor 3, and the ambient temperature around the drive pulley 12 and the ambient temperature inside the soundproof cover 16 are further increased. Can be suppressed. Further, since the end 11 of the drive pulley and the pulley nut 9 are exposed, it is easy to check the operation visually and excellent maintainability.

  Since the through hole 72 provided in the bearing holder 8 c is closed by the end portion 11 of the drive pulley and the bearing 10, noise does not leak from the through hole 72. The shape of the through-hole 72 provided in the bearing holder 8c may be a circle, an ellipse, or a rectangle, and the diameter of the circle, the major axis of the ellipse, and the diagonal length of the rectangle are made smaller than the outer shape of the bearing 10 so that noise does not leak.

  When the soundproof cover 16 for covering the timing belt 5 exposed from the wall member 7b and the driven pulley 4 is assembled, the soundproof cover 16 and the motor bracket 6 are connected so that there is as little gap as possible so that noise does not leak ( (See FIGS. 12 and 13). As shown in FIG. 12, there is a method in which the connecting portion covers the wall member 7b and the bearing holder 8c with the soundproof cover 16, and the gap is filled with packing or screwed so that no gap is generated. Further, as shown in FIG. 13, the soundproof cover 16 is abutted against the wall member 7b and the bearing holder 8c, and is screwed if necessary. If there is a gap in the abutting portion, it may be filled with packing or the like. The tension of the timing belt 5 can be adjusted by the tension bolt 24.

Next, a method for fixing the soundproof cover will be described.
As a method for fixing the soundproof cover 16, there are the following methods shown in FIGS. When the rear surface of the holding plate 2 is immediately behind the driven pulley 4 (see FIG. 3), a flange is provided on the outer edge of the soundproof cover 16 and the flange portion 25 is screwed to the holding plate 2 as shown in FIG. To do.
When there is a distance between the rear side of the driven pulley 4 and the back surface of the holding plate 2, the soundproof cover 16 is divided into a front side and a back side, the front side is a normal soundproof cover 16, and the back side is an upper supported by a stay 17 as shown in FIG. The cover 18 and the under cover 19 are used to cover the rear side of the timing belt 5 and the driven pulley 4 so that noise does not leak.

The soundproof cover 16 on the front side is fixed to the upper cover 18 and the under cover 19 by screwing. Since the position of the motor bracket 6, that is, the distance between the driving pulley 12 and the driven pulley 4 is slightly different depending on the machine by adjusting the timing belt 5, an adjustment cover 20 is provided between the motor bracket 6, the upper cover 18 and the under cover 19. You can fill in the gaps by arranging and adjusting.
At this time, the adjustment cover 20 may be screwed so that there is no gap in the motor bracket 6 or the gap may be filled with packing. If the fixing cover's fixing hole is made a long hole so that it can slide by the length of the long hole, it is possible to change the distance between the shafts by changing the reduction ratio of the driving pulley 12 and the driven pulley 4. it can. Note that the upper cover 18 and the under cover 19 may be integrated.

As shown in FIG. 16, instead of the stay 17 that supports the upper cover 18 and the under cover 19, a member extended from the holding plate 2 is used to fix the upper cover 18 and the under cover 19. The motor bracket 6 may be screwed. In the example of FIG. 16, one end of the upper cover 18 and the under cover 19 is screwed to the convex portion that supports the driven pulley 4 extending from the holding plate 2, and the other end is screwed to the motor bracket 6.
In the case of an injection molding machine having a plurality of drive devices using pulleys and timing belts in the transmission part, the above-described noise reduction structure of the present invention can be applied to a plurality of drive devices.

DESCRIPTION OF SYMBOLS 1 Drive apparatus 2 Holding plate 3 Motor 4 Driven pulley 5 Timing belt 6 Motor bracket 7a Conventional wall-shaped member 7b Wall-shaped member in this invention 8a Conventional bearing holder 8b Bearing holder in this invention 8c Bearing with a through-hole in this invention Holder 9 Pulley nut 10 Bearing 11 Drive pulley end 12 Drive pulley 13 Bearing holder fixing bolt 14 Motor shaft 15 Pulley flange 16 Soundproof cover 17 Stay 18 Upper cover 19 Undercover 20 Adjust cover 21 Adjust cover packing 22 Soundproof cover packing 23 Soundproof cover packing 24 Tension bolt 25 Soundproof cover flange part 70 Slit 72 Through hole

Claims (5)

A pulley and timing belt are used for the transmission part of the driving force, the motor as a driving source is fixed to the motor bracket, the driving pulley is fixed to the motor shaft, and the end of the driving pulley or the end of the motor shaft is supported by a bearing. In the drive device that is rotatably supported and the outer ring of the bearing is supported by the bearing holder,
A wall-like member is provided between the motor bracket and the bearing holder so as to cover the periphery of the drive pulley, or a bearing holder is provided on the motor bracket so as to cover the periphery of the drive pulley. Injection molding machine.   The injection molding machine according to claim 1, wherein the wall-shaped member is formed integrally with the motor bracket.   The injection molding machine according to claim 1, wherein the bearing holder is formed integrally with the motor bracket.   The injection molding machine according to any one of claims 1 to 3, wherein a timing belt and a driven pulley exposed to the outside are covered with a soundproof cover, and the soundproof cover is connected to the motor bracket.   The injection molding machine according to any one of claims 1 to 4, wherein a through hole smaller than an outer diameter of the bearing is formed in a central portion of the bearing holder.