JP6211305B2 - Injection molding machine - Google Patents

Description

  The present invention relates to an injection molding machine that injects a thermoplastic resin melted by a heating cylinder into a cavity of a closed mold from an injection nozzle, and in particular, the injection nozzle is brought into close contact with or separated from a resin injection port of the mold. The present invention relates to an injection molding machine provided with a nozzle touch mechanism.

  In general injection molding machines that have been used in the past, in order to inject molten resin from the injection nozzle into the mold cavity, the resin that adheres the tip of the injection nozzle to the fixed mold mounted on the fixed die plate An inlet is formed. The injection nozzle is advanced and retracted by a nozzle touch mechanism, and the tip of the injection nozzle is pressed against the resin injection port when the injection molding machine is operated, that is, when a molded body is manufactured.

  The nozzle touch mechanism of the electric injection molding machine includes a nozzle touch motor and a motion conversion mechanism that converts a rotational motion of the motor into a linear motion of the injection unit. A ball screw mechanism is generally used as the motion conversion mechanism. As related to such technology, in Patent Document 1 filed earlier by the applicant of the present application, a pair of ball screw mechanisms are arranged symmetrically with respect to the mechanical center of the injection unit, and one end of the pair of ball screw shafts is fixed. An injection molding machine fixed to a die plate is disclosed. In the injection molding machine disclosed in Patent Document 1, the nut body screwed to the ball screw shaft is held in the injection unit so that it can rotate and cannot be moved forward and backward, and when the nut body is rotationally driven by the nozzle touch motor, The nut body and the injection unit that holds the nut body are guided by the ball screw shaft and are driven forward and backward in the axial direction of the ball screw shaft. The injection nozzle is provided in the injection unit, and is brought into close contact with the resin injection port or separated from the resin injection port by driving the injection unit forward and backward.

JP-A-9-277306

  By the way, since the injection molding machine disclosed in Patent Document 1 has the ball screw shaft of the nozzle touch mechanism fixed to the fixed die plate, there is a problem that it is difficult to perform maintenance work of the injection unit, for example, cleaning of the tip of the injection nozzle. is there. In other words, the injection unit is usually mounted on the machine base so as to be able to turn to facilitate maintenance work, and at the time of maintenance, the tip of the injection nozzle can be turned in a horizontal plane in a direction away from the fixed die plate. It has become. However, in the injection molding machine disclosed in Patent Document 1, since one end of the ball screw shaft is fixed to the fixed die plate, the ball screw shaft and the fixed die plate are rotated each time work is performed in order to turn the injection unit. The bolts and nuts that are connected to each other must be removed and attached, and the maintenance work requires a lot of time and effort. In particular, in the case where a plurality of ball screw shafts are provided as in the injection molding machine disclosed in Patent Document 1, such inconvenience becomes significant.

  In order to eliminate such inconvenience, the applicant of the present application, as shown in FIG. 7, provides a unit base 2 on a machine base 1 of an injection molding machine so as to be able to turn, and an injection unit 3 on the unit base 2. It has been proposed first that the ball screw mechanism of the nozzle touch mechanism is mounted in the unit base 2 so that it can be moved forward and backward. The unit base 2 is formed in a box shape and is fixed to the upper surface of the machine base 1 using bolts 4. Further, the unit base 2 is connected to the machine base 1 through a turning shaft 4a. Therefore, the unit base 2 can be turned to an arbitrary angle around the turning shaft 4 a by removing the bolt 4.

  In FIG. 7, reference numeral 5 denotes a heating cylinder mounting bracket. A base end portion of the heating cylinder 6 is fixed to one surface of the heating cylinder mounting bracket 5, and an injection portion is injected to the distal end portion of the heating cylinder 6. The nozzle 7 is fixed. Further, a screw (not shown) for kneading the resin material is accommodated in the heating cylinder 6 so as to be rotatable and capable of moving forward and backward, and the base end portion of the screw is moved forward and backward on the unit base 2. The movable body 9 is attached to the movable body 9 so as to be rotatable.

  The screw is rotationally driven by a metering motor 10 and performs melting and kneading of the raw material resin supplied into the heating cylinder 6 from a raw material resin supply hopper (not shown) and weighing the heat-melted resin material. Further, the screw and the moving body 9 are driven forward and backward by an injection motor 11 and a required motion conversion mechanism (not shown). Reference numeral 12 in the figure denotes a guide rail provided on the unit base 2, and reference numeral 13 denotes a slider fixed to the moving body 9 and slidably engaged with the guide rail 12.

  The heating cylinder mounting bracket 5 is slidably connected to a guide rail 12 provided on the unit base 2 via a slider 14. The heating cylinder mounting bracket 5 is integrally formed with a nut body holding portion 5a, and a nut body 16 of a ball screw mechanism 15 constituting a nozzle touch mechanism is fixed to the nut body holding portion 5a. The nut body holding portion 5 a is disposed inside the unit base 2 through a through groove 18 formed in the top plate 17 of the unit base 2. In the unit base 2, a ball screw shaft 19 of the ball screw mechanism 15 is rotatably supported by bearings 20 and 21. The ball screw shaft 19 is rotationally driven by a nozzle touch motor via a required power transmission mechanism such as a timing belt. The nozzle touch motor is disposed on the back side of the unit base 2 in FIG. When the ball screw shaft 19 is rotationally driven using the nozzle touch motor, the nut body 16 screwed into the ball screw shaft 19 is driven forward and backward along the guide rail 12 together with the heating cylinder mounting bracket 5. Thereby, the injection nozzle 7 can be brought into close contact with the resin injection port, or the injection nozzle 7 can be separated from the resin injection port.

  In the injection molding machine previously proposed by the applicant of the present application, a unit base 2 is turnably provided on a machine base 1, and an injection unit 3 is attached to the unit base 2 so as to be able to advance and retreat. Is disposed in the unit base 2, when the injection unit 3 is turned on the machine base 1, it is not necessary to attach / remove the ball screw shaft 19, and the maintenance work of the injection unit can be facilitated.

  However, according to the said structure, the through-groove 18 of the nut body holding | maintenance part 5a must be opened in the top plate 17 of the unit base 2 over the movement range of the nut body holding | maintenance part 5a. For this reason, it has been pointed out that there is a problem that the raw material resin enters the unit base 2 through the through groove 18 and easily adheres to the ball screw shaft 19 and the bearings 20 and 21. It is also conceivable that when the operator of the injection molding machine climbs up and works on the machine base 1 during maintenance, the tool is accidentally removed and the ball screw shaft 19 or the like is damaged.

The present invention has been made to solve such problems, and prevents foreign matter from entering through grooves formed in the top plate of the unit base, is easy to maintain, and has excellent durability. An object of the present invention is to provide an injection molding machine.

To solve such problems, the present invention is provided with a unit base pivotably on the machine base, mounted for advancing and retracting the heating cylinder mounting bracket of the injection unit on the unit base, the heating cylinder mounting bracket The nut body of the fixed ball screw mechanism is screwed into the ball screw shaft of the ball screw mechanism that is rotatably arranged in the unit base through the through groove provided in the top plate of the unit base, and the ball screw shaft is connected to the nozzle. In the injection molding machine that is rotationally driven by a touch motor, the through groove formed in the top plate of the unit base is covered with a cover sheet that expands and contracts as the heating cylinder mounting bracket advances and retreats.

  Thus, when the upper surface of the unit base is covered with the cover sheet that expands and contracts as the heating cylinder mounting bracket advances and retreats, the through groove of the nut body holding portion provided in the top plate of the unit base can be covered with the cover sheet. Therefore, it is possible to prevent foreign substances such as raw material resin from entering the unit base.

  In the injection molding machine having the above-described configuration, the cover sheet may be a cover sheet that is rotatably supported in a casing and wound around a rotating shaft that is constantly urged in one direction by an elastic member. It is characterized by.

  Since the cover sheet having such a configuration is compact and inexpensive, the design of the injection molding machine with the cover sheet can be easily designed and can be implemented at low cost.

  According to the present invention, in the injection molding machine configured as described above, the casing is fixed to the heating cylinder mounting bracket, and the end portion on the drawer side of the cover sheet is fixed to the end portion of the unit base.

  According to such a configuration, the upper surface of the unit base can be covered with the cover sheet without arranging a large-sized casing at the end of the unit base, so that maintenance around the injection unit can be facilitated.

  According to the present invention, the upper surface of the unit base is covered with the cover sheet that expands and contracts as the heating cylinder mounting bracket advances and retreats. It is possible to prevent foreign substances such as molten resin from entering the unit base. Therefore, the maintenance of the ball screw shaft and the bearing can be facilitated, and the failure of the injection molding machine due to the damage of these members can be eliminated. Further, since the cover sheet that expands and contracts as the heating cylinder mounting bracket moves forward and backward is used, the heating cylinder mounting bracket can be stably moved forward and backward without hindering the advancement and retraction of the heating cylinder mounting bracket by the cover sheet.

It is a principal part perspective view which shows the state at the time of the nozzle touch of the injection molding machine which concerns on embodiment. It is a principal part perspective view which shows the state at the time of nozzle backward movement of the injection molding machine which concerns on embodiment. It is a perspective view of the cover member concerning an embodiment. It is a top view which shows the state which removed the injection unit of the injection molding machine which concerns on embodiment. It is a principal part perspective view which shows the state which removed the cover member of the injection molding machine which concerns on embodiment. It is a principal part perspective view which shows the state which removed the top plate of the unit base of the injection molding machine which concerns on embodiment. It is principal part sectional drawing of the injection molding machine which the applicant of this application proposed previously.

  Hereinafter, an embodiment of an injection molding machine according to the present invention will be described with reference to the drawings. It should be noted that the gist of the present invention is not limited to the following embodiments, and can be easily applied to injection molding machines having other configurations without departing from the spirit of the invention. is there.

  The injection molding machine according to the embodiment is also the same as the injection molding machine (see FIG. 7) previously proposed by the applicant of the present application regarding the basic configuration. Therefore, the same code | symbol is attached | subjected to the part corresponding to FIG. 7 in FIGS. 1 to 6, 1 is a machine base of an injection molding machine, 2 is a unit base, 3 is an injection unit, 4 is a bolt, 4a is a pivot, 5 is a heating cylinder mounting bracket, 6 is a heating cylinder, 9 Is a moving body, 12 is a guide rail, 15 is a ball screw mechanism, 16 is a nut body, 17 is a top plate of the unit base 2, 18 is a through groove formed in the top plate 17, 19 is a ball screw shaft, and 20 and 21 are bearings. Is shown. In these figures, reference numeral 22 is a power transmission mechanism such as a timing belt, reference numeral 23 is a hopper for supplying a raw material resin, reference numeral 24 is a cover case covering the outer periphery of the injection unit 3, and reference numeral 25 is for turning the unit base 2. The roller, 26 is a fixing member of the unit base 2, and 30 is a cover member that covers the upper surface of the unit base 2.

  As shown in FIGS. 1, 2, 4, 5, and 6, the unit base 2 includes a bottom plate 27 and two side plates 28 erected in parallel from two opposite sides of the bottom plate 27. The guide rails are fixed to the upper surface of the side plate 27, respectively. The unit base 2 is connected to the machine base 1 through a turning shaft 4a so as to be turnable. In a normal state other than during maintenance, the unit base 2 is fixed to a fixed position on the machine base 1 using bolts 4.

  The fixing member 26 is formed in a wedge shape, and is inserted between the upper surface of the machine base 1 and the lower surface of the unit base 2. The fixing member 26 is connected to the end of the unit base 2 using a bolt 26a. Therefore, the fixing member 26 changes the height of the injection nozzle provided in the unit base 2 and the injection unit 3 with respect to the upper surface of the machine base 1 and the height of the turning roller 25 by changing the tightening amount of the bolt 26a. The position can be adjusted. That is, in a normal state other than during maintenance (turning), the height of the injection nozzle is adjusted to the mold resin injection port by adjusting the amount of the fixing member 26 entering the unit base using the bolt 26a. The unit base 2 is fixed on the machine base 1 using bolts 4. At this time, the turning roller 25 has a height that does not contact the machine base 1. During maintenance (when turning), after the bolt 4 is removed, the tightening amount of the bolt 26a is adjusted to a height at which the turning roller 25 is in contact with the machine base 1, and then the turning shaft 4a is the center. The unit base 2 is turned in a required direction.

As shown in FIG. 4, the top plate 17 of the unit base 2 is formed in a size that covers about half of the unit base 2 on the nozzle touch side, and is formed in the heating cylinder mounting bracket 5 at the center thereof. A through groove 18 for penetrating the nut body holding portion 5a is formed. As shown in FIG. 4, the through groove 18 is formed so as not to interfere with the nut body holding portion 5 a over at least the movement range of the nut body holding portion 5 a. Thus, since the through-hole 18 is formed in the top plate 17, when the cover member 30 is not provided on the upper surface of the top plate 17, the ball screw shaft 15 of the ball screw mechanism is exposed as shown in FIG. In addition, foreign materials such as a raw material resin adhere to the ball screw shaft 15 or are likely to collide.

  As shown in FIG. 3, the cover member 30 is rotatably supported in the housing 31, is rotatably supported in the housing 31, and is always urged in one direction by the elastic force of an elastic member (not shown), and the rotation The cover sheet 33 is wound around a shaft 32 and has a leading end pulled out from a drawer port 31 a formed on the front surface of the housing 31. The cover sheet 33 is made of, for example, a rubberized cloth. Prior to the setting to the injection molding machine, the cover sheet 33 is wound around the rotary shaft 32 that is always urged in one direction by the elastic force of an elastic member (not shown) as shown by a solid line in FIG. Only the outside is exposed. From this state, when the front end portion of the cover sheet 33 is gripped and pulled, the cover sheet 33 is pulled out from the housing 31 against the elastic force of an elastic member (not shown) as shown by a broken line in FIG. Further, when the force applied to the cover sheet 33 is removed from this state, the cover sheet 33 is drawn into the housing 31 by the elastic force of an elastic member (not shown). Since the cover member 30 having such a configuration is compact and inexpensive, the use of the cover member 30 makes it easy to design an injection molding machine with a cover sheet, and allows the injection molding machine with a cover to be implemented at a low cost.

  In the present embodiment, as shown in FIGS. 1 and 2, the housing 31 is fixed to the front surface of the heating cylinder mounting bracket 5, and the end of the cover sheet 33 on the drawer side is fixed to the end of the unit base 2. The cover sheet 33 covers the top surface of the top plate 17. In this way, since the large-sized casing 31 is not disposed at the end of the unit base 2, maintenance around the injection unit can be facilitated. Further, since the cover sheet 33 is disposed on the top surface of the top plate 17, even when the cover sheet 33 having a somewhat low rigidity is used, the deformation of the cover sheet 33 due to gravity can be prevented or suppressed, and the through groove 18 is formed. Can be shielded reliably.

  When the nozzle is touched, the heating cylinder mounting bracket 5 moves to the front side of the unit base 2 as shown in FIG. At this time, the cover sheet 33 is wound around the rotating shaft 32 by the elastic force of an elastic member (not shown) and drawn into the housing 31. Further, when the nozzle is retracted, the heating cylinder mounting bracket 5 moves to the rear side of the unit base 2 as shown in FIG. At this time, the cover sheet 33 is pulled out from the housing 31 against the elastic force of an elastic member (not shown).

  Therefore, regardless of the movement of the unit base 2, the through groove 18 is always covered with the cover sheet 33, and foreign matter can be prevented from entering the unit base 2 from the through groove 18. Therefore, the maintenance of the ball screw shaft 19 and the bearings 20 and 21 can be facilitated, and the failure of the injection molding machine due to the damage of these members can be eliminated. Further, since the cover sheet that expands and contracts as the heating cylinder mounting bracket 5 advances and retracts is used, the heating cylinder mounting bracket can be moved forward and backward stably without hindering the advancement and retraction of the heating cylinder mounting bracket by the cover sheet.

  The gist of the present invention is not limited to the above embodiment, and various modifications can be made within the scope of the gist of the present invention. For example, in the above-described embodiment, the cover sheet 33 is made of rubberized cloth, but instead of such a configuration, a shutter type cover sheet in which a plurality of metal pieces are slidably combined may be used. . Moreover, in the said embodiment, although the housing 31 was fixed to the heating cylinder attachment bracket 5, when it does not interfere with a maintenance operation | work, the housing 31 can also be fixed to the unit base 2. FIG. Further, in the embodiment, the top plate 17 is disposed on the upper surface of the unit base 2 and the cover sheet 33 of the cover member 30 is disposed on the upper surface of the top plate 17. However, the cover sheet 33 has sufficient rigidity on the ocean. When it has, the top plate 17 can also be abbreviate | omitted.

DESCRIPTION OF SYMBOLS 1 Machine base 2 Unit base 3 Injection unit 4 Bolt 4a Rotating shaft 5 Heating cylinder mounting bracket 5a Nut body holding part 6 Heating cylinder 7 Injection nozzle 9 Moving body 10 Measuring motor 11 Injection motor 12 Guide rail 13, 14 Slider 15 Ball screw Mechanism 16 Nut body 17 Top plate 18 Through groove 19 Ball screw shaft 20, 21 Bearing 22 Power transmission mechanism 23 Hopper 24 Cover case 25 Turning roller 26 Fixing member 26a Bolt 27 Bottom plate 28 Side plate 30 Cover member 31 Housing 32 Rotating shaft 33 Cover sheet

Claims (3)

On the machine frame provided with a unit base pivotably, mounted for advancing and retracting the heating cylinder mounting bracket of the injection unit on the unit base, the nut of the ball screw mechanism is fixed to the heating cylinder mounting bracket, the unit base In an injection molding machine that is threadedly engaged with a ball screw shaft of a ball screw mechanism that is rotatably arranged in the unit base through a through groove formed in the top plate, and the ball screw shaft is rotationally driven by a nozzle touch motor.
An injection molding machine, wherein the through groove formed in the top plate of the unit base is covered with a cover sheet that expands and contracts as the heating cylinder mounting bracket advances and retreats.   2. The cover sheet according to claim 1, wherein the cover sheet is rotatably supported in a casing and wound around a rotating shaft that is always urged in one direction by an elastic force of an elastic member. Injection molding machine.   The injection molding machine according to claim 2, wherein the casing is fixed to the heating cylinder mounting bracket, and an end portion on the drawer side of the cover sheet is fixed to an end portion of the unit base.