JPH09234765A - Nozzle touch apparatus of injection molding machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To constitute an injection molding machine beautifully and compactly and to prevent a fixed platen from being slanted by nozzle touch force. SOLUTION: A nozzle touch apparatus 10 is composed of two nozzle driving units 11, 11', which are arranged between an injection unit 1 and a mold unit 30 with the axis of an injection nozzle 8 made to be the center of symmetry. The nozzle driving units 11, 11' are composed of rod-shaped moving screws 13, 13', tubular fixed shafts 12, 12' the base end parts of which are fixed to a fixed platen 31, and fixing nuts combined with the screws 13, 13'. When the screws 13, 13' are rotated to advance, making the injection nozzle 8 touch the fixed platen 31.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention drives an injection nozzle of an injection unit in a direction in which it touches a mold unit and separates it from the mold unit, and abuts the injection nozzle on the mold unit with a predetermined touch force. The present invention relates to a nozzle touch device for an injection molding machine, which is held.

[0002]

2. Description of the Related Art An injection molding machine, which is well known in the art, is schematically composed of an injection unit 50, a mold unit 55, a nozzle touch device 60, etc., as shown in FIG. ing. The injection unit 50 is composed of a cylinder barrel, a screw that is rotationally driven in the cylinder barrel and is also driven in the axial direction, a drive device that drives the screw, and the like. An injection nozzle 51 is provided in front of the cylinder barrel of the injection unit 50. On the other hand, the mold unit 55 includes the fixed mold 5
6 is attached to the fixed platen, the movable platen is attached to the movable platen, the movable platen is clamped to the fixed platen or is driven in the mold opening direction, and the mold is clamped with a predetermined pressure. It is composed of a mold clamping device and the like.

Nozzle touch devices are also well known in the art,
For example, a device proposed by Japanese Examined Patent Publication No. 4-46732 is known. This nozzle touch device 60 is shown in FIG.
As shown in FIG. 3, the feed screw 61 and a movable nut 62 screwed onto the feed screw 61 are included. Both ends of the feed screw 61 are attached to the supporting devices 63, 6
4 is rotatably supported by a feed screw drive mechanism provided inside the support device 64. A bracket 65 is provided below the injection unit 50.
Is fixed, and the movable nut 62 of the nozzle touch device 60 is fixed.
The compression spring 66 on the bracket 65 of the injection unit 50.
Fixed through. Thus, the nozzle touch device 60 including the feed screw 61 and the movable nut 62
Below the injection unit 50,
And are provided separately. The lower end of the movable plate 57 is fixed to the upper end of the support device 64 by a member 59.

Therefore, when the feed screw 61 of the nozzle touch device 60 is rotationally driven, the movable nut 62 moves in the axial direction, and the injection unit 50 fixed to the movable nut 62 is driven toward the mold unit 55. It Then, the injection nozzle 51 is made to touch the spool bush of the mold unit 55, and the screw of the injection unit 50 is driven in the axial direction while the predetermined touch force is maintained, and the measured molten resin is clamped. When injection into the mold 56, an injection molded product is obtained.

[0005]

As described above, the conventional nozzle touch device 60 can also cause the injection nozzle 51 to touch the spool bush of the mold unit 55 and maintain a predetermined touch force. Especially, in the nozzle touch device 60, since the compression spring 66 is interposed between the movable nut 62 and the injection unit 50, the injection nozzle 51 is touched with a predetermined touch force regardless of the position or the depth of the mold 56. The excellent feature that it can be recognized is recognized. However, since the nozzle touch device 60 is arranged below the injection unit 50 in a state of being separated from and exposed to the injection unit 50, there is room for improvement from an aesthetic point of view or from the viewpoint of making the injection molding machine compact. . For example, when the nozzle touch device 60 is arranged at a point C between the injection unit 50 and the mold unit 55, the nozzle touch device 60 can be neatly designed and can be made compact. 62 is a structure that moves in the axial direction, and the feed screw 6
As shown by the dotted line, the rear end portion 61 ′ of the No. 1 is located inside the injection unit 50, and the internal structure of the injection unit 50 is complicated, and such an arrangement has a problem in implementation. In addition, the lower end of the fixed platen 57 is the member 5
Since it is fixed to the upper end of the supporting device 64 by 9,
When the injection nozzle 51 is brought into contact with the spool bush of the mold unit 55, it is expected that the fixed platen 57 will be tilted by a rotational moment acting around the member 59. Particularly in the above-mentioned conventional example, since the nozzle touch device 60 is arranged below the injection unit 50 and the axial distance d between the injection nozzle 51 of the injection unit 50 and the feed screw 61 is large, a large rotational moment acts, The inclination of the fixed platen 57 is also expected to be large. As described above, if the mold 56 is clamped in a state of being greatly inclined, the mold 56 may be damaged.

The present invention has been made in view of the above-mentioned conventional problems. Specifically, the injection molding machine can be constructed aesthetically and compactly, and the fixed platen can be fixed by the nozzle touch force. It is an object of the present invention to provide a nozzle touch device for an injection molding machine that is hard to tilt. In addition to the above object, another object of the present invention is to provide a nozzle touch device of an injection molding machine in which the fixed platen does not tilt even with a large nozzle touch force.

[0007]

In order to achieve the above object, the present invention provides an injection unit including an injection nozzle, a cylinder barrel, a screw, and the like, and a mold unit including a mold, a mold clamping device, and the like. A nozzle touch device that drives the injection nozzle of the injection unit in a direction in which it touches the mold unit and in a direction in which it separates, and holds the injection nozzle in contact with the mold unit with a predetermined touch force. In the injection molding machine described above, the nozzle touch device includes a nozzle drive unit disposed between the injection unit and the mold unit, and the nozzle drive unit includes a rod-shaped moving screw that is rotationally driven, and the moving screw. When the moving screw is driven to rotate, the moving screw moves in the axial direction and the injection nozzle moves in the axial direction. Configured to be dynamic. According to a second aspect of the present invention, in the nozzle drive unit according to the first aspect, a rod-shaped moving screw, a tubular fixed shaft whose base end is fixed to the mold unit, and a fixing screwed to the moving screw. A nut, and one end of the moving screw is rotatably provided in the injection unit in a state where movement in the axial direction is restrained, and the other end is movably inserted into the fixed shaft, The fixing nut is fixed to the mold unit via a compression spring, and the invention according to claim 3 is the method according to claim 2
Alternatively, a plurality of nozzle drive units described in 3 are arranged with the axis of the injection nozzle substantially as a symmetrical center.

[0008]

BEST MODE FOR CARRYING OUT THE INVENTION Embodiments of the present invention will be described below with reference to FIGS. As shown in FIG. 1, the injection molding machine according to the present embodiment includes an injection unit 1, a mold unit 30 disposed on the left front side in the drawing of the injection unit 1, and an injection unit. 1 and a nozzle unit 10 arranged between the mold unit 30.

The injection unit 1 includes a plurality of shafts 2, 2, ...
A rear plate 3, an intermediate plate 4, a front plate 5 and the like connected to each other are provided, and a conventionally known screw drive device 6 and the like are provided between these plates 3 and 4. A cylinder barrel 7 extends forward from the front plate 5, a screw is provided inside the cylinder barrel 7, and an injection nozzle 8 is provided at the tip end thereof in a known manner. Although only a part of the mold unit 30 is shown in FIG. 1, a fixed platen 31, a movable platen which makes a pair with the fixed platen 31, and a fixed platen 31 and a movable platen are connected to each other as is well known in the art. , Four tie bars 32, 32, ..., A fixed mold 33 attached to the fixed platen 31, a mold clamping device, and the like. The fixed mold 33 is provided with a spool bush 34 at a position facing the injection nozzle 8.

In the embodiment shown in FIG. 1, the nozzle touch device 10 comprises two nozzle drive units 11 arranged with the axis of the injection nozzle 8 as the center of symmetry.
11 '. These nozzle drive units 11 and 11 ′ are different from the other nozzle drive unit 11 ′ in that the detection switch 26 is attached to one nozzle drive unit 11, and the other configurations are the same. Therefore, hereinafter, the nozzle drive unit 11 shown mainly above will be described, and when describing the lower nozzle drive unit 11 ', the same reference numerals will be appended with a dash "'".

The nozzle drive unit 11 is roughly composed of a tubular fixed shaft 12 and a rod-shaped moving ball screw 13 which is provided in the tubular fixed shaft 12 so as to be freely inserted and removed. The front end portion of the tubular fixed shaft 12 is fixed to the rear surface of the fixed platen 31, the rear end portion extends toward the injection unit 1, and the end portion is free and the nut case 14 is attached as described later. There is. The rear end portion of the moving ball screw 13 is attached to the front plate 5 in a state where it can rotate but is prevented from moving in the axial direction, and the front end portion extends over the inside of the nut case 14 and reaches the tubular fixed shaft 12. ing. Thus, as shown in FIG. 1, the nozzle drive unit 11 is provided between the injection unit 1 and the mold unit 30.

FIG. 2 is an enlarged sectional view of the portion A in FIG. 1. As shown in FIG. 2, a tubular fixed shaft 1 is provided.
A flange 15 is formed integrally with the rear end of the flange 2 and extends radially outward. The front end of the nut case 14 is detachably fixed to the flange 15 by means such as bolts and nuts. The nut case 14 has a predetermined length in the axial direction, and a spring receiving flange 16 that extends radially inward is formed at the rear end portion.

In the nut case 14, there are provided a fixed ball nut 20, a sleeve 23, and a compression spring 27 which are screwed into the moving ball screw 13. Fixed ball nut 2
0 has a mounting flange 21 at the rear end. A spring receiving flange 24 is formed at the front end of the sleeve 23 and receives one of the compression springs 27 and is fixed to the mounting flange 21 of the fixed ball nut 20. Sleeve 2
The rear end of the nut 3 extends out of the nut case 14, and a male screw 28 with which an adjusting nut 29 is screwed is formed on the outer peripheral portion of the rear end. The nut case 14 has a proximity switch 26
When the adjusting nut 29 approaches a predetermined distance, it is detected that the injection nozzle 8 touches the spool bush 34 with a predetermined touch force.

The nozzle drive unit 11 can be assembled as follows. That is, the mounting flange 21 of the fixed ball nut 20 and the spring receiving flange 24 of the sleeve 23 are integrated with a bolt / nut or the like. Further, the compression spring 27 is loosely inserted in the outer peripheral portion of the sleeve 23. The nut case 14 is attached to the flange 1 of the tubular fixed shaft 12.
5, the sleeve 23 is inserted into the moving ball screw 13, and the fixed ball nut 20 is rotated to a predetermined position. Next, the nut case 14 is attached to the flange 15 of the tubular fixed shaft 12. Then, the adjusting nut 29 is screwed into the spring receiving flange 2 of the sleeve 23.
4 and the spring receiving flange 16 of the nut case 14 so that the compression spring 27 is slightly compressed. As a result, the spring receiving flange 16 of the nut case 14 and the adjusting nut 29 are in frictional contact with each other. Therefore, the fixed ball nut 20 is fixed to the fixed platen 31 via the sleeve 23, the adjustment nut 29, the nut case 14, and the tubular fixed shaft 12.

The rear end portion of the moving ball screw 13 'is shown in FIG.
As shown in FIG. 3, the diameter is reduced to have a stepped portion to form a small shaft portion. The sleeve 4 is attached to the small shaft.
The inner ring 41 'of the ball bearing 40' is press-fitted via 9 '. Also, the outer ring 4 of the ball bearing 40 '
2'is fixed to the front plate 5 by a pressing flange 43 '. Male screw 4 on the outer periphery of the right end of the small shaft
4'is formed, and the position of the moving ball screw 13 'is determined by a tightening nut 45' screwed to the male screw 44 '. With this configuration, the moving ball screw 13 ′ can rotate with respect to the front plate 5, but when moving in the axial direction, the front plate 5 also moves together. A driven pulley 46 'is attached to the end of the moving ball screw 13' with a key 47 'and a push plate 48'.

At the upper end of the front plate 5, an electric motor 37 is attached by a mounting bracket 36, as shown in FIG.
Is attached. The drive pulley 38 fixed to the output shaft of the electric motor 37, the moving ball screws 13, 1
A timing belt 39 is wound around the driven pulleys 46, 46 'of 3'.

Next, the operation will be described. The electric motor 37 is activated in the nozzle touch direction. Then, the driven pulleys 46 and 46 'are rotationally driven in synchronization by the timing belt 39. Therefore, the moving ball screws 13, 1
3'is also rotationally driven in synchronization. Moving ball screw 13,
Fixed ball nuts 20 and 20 'screwed to 13'
Is fixed to the fixed platen 31 via the sleeves 23 and 23 ', the adjusting nuts 29 and 29', the nut cases 14 and 14 ', and the tubular fixed shafts 12 and 12' as described above, so that it cannot rotate. Not possible, moving ball screw 1
Relative rotation occurs between 3, 13 'and the fixed ball nuts 20, 20', and the fixed ball nuts 20, 20 'are
1 and 2, trying to move to the right rear,
The nut cases 14 and 1 through the compression springs 27 and 27 '.
The movement is temporarily blocked by the spring receiving flanges 16 and 16 'of 4'. Therefore, the moving ball screws 13 and 13 'having a small resistance move forward in the tubular fixed shafts 12 and 12' to the left. That is, the front plate 5 advances in the nozzle touch direction.

When the injection nozzle 8 mounted on the front plate 5 touches the spool bush 34, the moving ball screws 13 and 13 'cannot move forward anymore, so this time the fixed ball nut having a relatively small resistance. 20, 2
0's move backward while compressing the compression springs 27, 27 '. When the compression springs 27, 27 'are compressed by a predetermined amount, the adjusting nut 29 approaches the proximity switch 26 in the embodiment shown in the drawing, and the injection nozzle 8 touches the spool bush 34 with a predetermined touch force. Detect that there is. This completes the nozzle touch. Less than,
As is well known, the molten resin is injected into the mold 33 of the mold unit 30 that has been clamped. Wait for cooling and solidification, open the mold and take out the molded product. If necessary, the electric motor 37 is reversely rotated to separate the injection nozzle 8 from the spool bush 34.

The present invention can be implemented in various forms without being limited to the illustrated embodiment. For example, in the above-described embodiment, two nozzle drive units 11 and 11 ′ are provided with the axis of the injection nozzle 8 as the center of symmetry, so that when the injection nozzle 8 touches the spool bush 34, the touch force is increased. However, the fixed platen 31 does not tilt as in the conventional case, but the nozzle drive unit 11 '
Even if there is only one, the nozzle drive unit 11 ′ is provided between the injection unit 1 and the mold unit 30, and the inter-axis distance D between the injection nozzle 8 and the tubular fixed shaft 12 ′ is the same as the conventional shaft. Since the distance is smaller than the distance d, the rotational moment is small and the fixed platen 31 is hard to tilt. Therefore, one nozzle drive unit 11 or 11 'can also be used. Further, in the above-described embodiment, the moving ball screws 13 and 13 ′ are attached to the front plate 5, but when the electric motor 37 is attached to the fixed platen 31, the moving ball screws 13 and 13 ′ are attached to the fixed platen 31 side. , And tubular fixed shafts 12, 12 ′ can also be provided on the front plate 5. Furthermore, the proximity switch 26 also
It is obvious that the present invention is not limited to the illustrated embodiment, and can be implemented in the same manner even if it is provided in another place.

[0020]

As described above, according to the present invention, the nozzle drive unit that constitutes the nozzle touch device is composed of the rod-shaped moving screw that is rotationally driven and the fixed nut that is screwed into the moving screw. When the moving screw is driven to rotate, the moving screw moves in the axial direction to drive the injection nozzle in the axial direction. Can be placed at. Therefore, according to the present invention, the effect peculiar to the present invention that the injection molding machine can be configured aesthetically and compactly is obtained. Further, according to the present invention, since the nozzle drive unit is arranged between the injection unit and the mold unit, the axial distance between the injection nozzle and the nozzle drive unit is shortened, and the mold is operated with a small nozzle touch force. There is also an effect that the unit, that is, the fixed platen does not tilt as in the conventional case. Further, according to another aspect of the invention, since the plurality of nozzle driving units are provided substantially with the axis of the injection nozzle as a center of symmetry, the nozzle touch force is balanced, and the fixed platen falls down even with a large nozzle touch force. There is no such thing.

[Brief description of drawings]

FIG. 1 is a front view showing an embodiment of the present invention.

FIG. 2 is an enlarged sectional view of a portion indicated by A in FIG.

FIG. 3 is an enlarged sectional view of a portion indicated by B in FIG.

FIG. 4 is a front view showing a conventional example.

[Explanation of symbols]

1 injection unit 5 front plate 8 injection nozzle 10 nozzle touch device 11, 11 'nozzle drive unit 12, 12' tubular fixed shaft 13, 13 'moving ball screw 20, 20' fixed ball nut 27, 27 'compression spring 30 mold Unit 31 Fixed platen 34 Spool bush

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[Procedure amendment]

[Submission date] April 12, 1996

[Procedure amendment 1]

[Document name to be amended] Statement

[Name of item to be corrected] 0002

[Correction method] Change

[Correction contents]

[0002]

2. Description of the Related Art An injection molding machine, which is well known in the art, is schematically composed of an injection unit 50, a mold unit 55, a nozzle touch device 60, etc., as shown in FIG. ing. The injection unit 50 is composed of a cylinder barrel, a screw that is rotationally driven in the cylinder barrel and is also driven in the axial direction, a drive device that drives the screw, and the like. An injection nozzle 51 is provided in front of the cylinder barrel of the injection unit 50. On the other hand, the mold unit 55 includes the fixed mold 5
6 is attached to the fixed platen, the movable platen is attached to the movable platen , and the movable platen is clamped to the fixed platen or driven in the mold opening direction, and the mold is clamped with a predetermined pressure. It is composed of a mold clamping device and the like.

[Procedure amendment 2]

[Document name to be amended] Statement

[Name of item to be corrected] 0003

[Correction method] Change

[Correction contents]

Nozzle touch devices are also well known in the art,
For example, a device proposed by Japanese Patent Publication No. 4-46732 is known. This nozzle touch device 60 is shown in FIG.
As shown in FIG. 3, the feed screw 61 and a movable nut 62 screwed onto the feed screw 61 are included. Both ends of the feed screw 61 are attached to the supporting devices 63, 6
4 is rotatably supported by a feed screw drive mechanism provided inside the support device 64. A bracket 65 is provided below the injection unit 50.
Is fixed, and the movable nut 62 of the nozzle touch device 60 is fixed.
The compression spring 66 on the bracket 65 of the injection unit 50.
Fixed through. Thus, the nozzle touch device 60 including the feed screw 61 and the movable nut 62
Below the injection unit 50,
And are provided separately. The lower end of the fixed platen 57 is fixed to the upper end of the support device 64 by a member 59.

Claims (3)

[Claims] 1. An injection unit (1) comprising an injection nozzle (8), a cylinder barrel (7), a screw and the like,
Mold unit (3) including a mold (33) and a mold clamping device
0) and the injection nozzle (8) of the injection unit (1) are driven in a direction in which they touch the mold unit (30, 34) and a direction in which they are separated from each other, and the injection nozzle (8) is set to a predetermined position. With the touch force of the mold unit (30,
34) An injection molding machine including a nozzle touch device (10) that is held in contact with the nozzle touch device (34), the nozzle touch device (10) being disposed between the injection unit (1) and the mold unit (30). The nozzle drive unit (11, 11 '), the nozzle drive unit (11, 11') is a rod-shaped moving screw (13, 13 ') that is rotationally driven, and the moving screw (13, 1').
3 ') and a fixed nut (20, 20') screwed together. When the moving screw (13, 13 ') is driven to rotate, the moving screw (13, 13') moves in the axial direction. Then, the injection nozzle (8) is axially driven, and a nozzle touch device of an injection molding machine. 2. A nozzle drive unit (1) according to claim 1.
1, 11 ') are rod-shaped moving screws (13, 13'),
A tubular fixed shaft (12, 12 ′) whose base end is fixed to the mold unit (30, 31), and the moving screw (1
(3, 13 ') and a fixed nut (20, 20') screwed together, and one end of the moving screw (13, 13 ') can be moved in the axial direction by the injection unit (1, 5). It is rotatably provided in a restrained state, and the other end is fixed shaft (1
Injection molding in which the fixing nut (20, 20 ') is movably inserted into the mold unit (30, 31) via a compression spring (27, 27'). Machine nozzle touch device. 3. A nozzle drive unit (11, 11 ') according to claim 2 or 3, wherein a plurality of nozzle drive units (11, 11') are arranged substantially with the axis of the injection nozzle (8) as the center of symmetry. Nozzle touch device.