JP3290154B2 - Extraction structure and extraction method of tie bar of molding device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a structure and a method for extracting a tie bar of a molding apparatus.

[0002]

2. Description of the Related Art In an injection molding apparatus, for example, a movable platen is usually provided along four tie bars (stays) provided between a fixed plate fixed on a base and a fixing portion on a mold clamping means side. It moves back and forth by the operation of the fastening means. A molding die is mounted on the opposing surfaces of the fixed platen and the movable platen to form a molded product. The molding die needs to be replaced each time according to the type of molded product. .

[0003] Exchange (including attachment) of a molding die is usually carried out by lifting the die from the space above the four stays by a crane or the like outside the apparatus. However,
If the mold is large or the ceiling is too low to provide enough space above the stay, remove the necessary stay (generally, one of the upper stays) from the fixed platen, expand the space, and then remove the mold. An exchange takes place.

[0004] The applicant of the present invention has previously described Japanese Patent Application Laid-Open No. 9-57803.
In Japanese Patent Laid-Open Publication No. H10-210, a mechanism for extracting a tie bar in this seed forming apparatus was proposed. In this mechanism, an extraction holding stay is provided on a fixed plate with an engagement holding member capable of disengaging, and a movable plate is provided with a stay clamp device for gripping the stay. Is released, the stay is pulled out of the fixed platen together with the retraction of the movable platen, and moves to the mold closing device side. However, during the actual extraction operation, the engaging portion of the stay to be extracted is tightly engaged with the engaging portion of the engaging and holding member of the fixed platen. There was a problem that it could not be released.

[0005] In addition, a small gap (0.5 mm or less) is required between the engaging portion of the stay to be extracted and the engagement holding member for releasing the engagement between the engaging and retaining members. However, the gap for releasing the engagement causes a dimensional difference with stays other than the stay to be extracted. This dimensional difference hinders the parallelism between the fixed platen and the mold clamping device, causing stress to concentrate on the stays other than the extracted stay and causing breakage, as well as poor molding accuracy during molding. Invite.

[0006]

SUMMARY OF THE INVENTION Therefore, the present invention
The engaging part of the stay to be removed and the engaging part of the engagement holding member of the fixed plate can be easily disengaged, and the dimensional difference between the stay to be removed and the other stays can be eliminated. The present invention aims to provide a novel tie bar extracting structure of a molding apparatus and a method of extracting the tie bar, which can ensure a high degree of parallelism between the tie bar and a specific stay, eliminate stress concentration on a specific stay, and perform highly accurate molding. It is assumed that.

[0007]

That is, according to the first aspect of the present invention, there is provided a mold clamping means for pressing a movable plate against a fixed plate, and a movable plate mounted on the fixed plate for moving the movable plate relative to the fixed plate. A molding apparatus having a mold opening / closing means and a plurality of stays provided between the fixed board and the mold clamping means for sliding the movable board, wherein each of the stays is a fixed board side mounting portion. A fixed length is formed between the engaging portion to which the engaging and holding member is engaged and the mounting step formed on the mold clamping means side mounting portion, and at least in the stay to be removed among the stays, the fixing is performed. It has an abutment step that abuts a holding step formed inside the through hole of the board, and the abutment step penetrates while maintaining a slight holding gap with the holding step of the through hole. And the engagement holding member of the to-be-extracted stay is provided with the abutting step. A detaching means capable of releasing the engagement with the engaging portion when the retaining plate is brought into contact with the holding step portion of the through hole is provided, and the movable platen includes at least the to-be-extracted stay. The present invention relates to a tie bar extracting structure of a molding apparatus, wherein a stay clamp means that can be gripped so as to be able to move integrally with a movable plate is provided.

According to a second aspect of the present invention, in the first aspect, the tie bar of the forming apparatus is provided in which the stay clamping means is provided on the stay to be extracted and a stay substantially diagonally positioned with respect to the stay to be extracted. According to the structure.

Further, the invention of claim 3 relates to a method invention, and mold clamping means for pressing a movable plate against a fixed plate,
A mold opening / closing means installed on a fixed plate for moving the movable plate with respect to the fixed plate; and a plurality of stays provided between the fixed plate and the mold clamping unit for sliding the movable plate. In the method of removing the stay in the molding device having, each of the stays, an engaging portion to which the engagement holding member of the fixed platen side mounting portion is engaged, and a mounting step formed on the mold clamping means side mounting portion, Is configured to have a fixed length, and at least the stay to be removed among the stays has an abutment step that abuts a holding step formed inside a through hole of the fixed plate, The abutting step is held through with a slight holding gap between the abutting step and the holding step of the through hole, and the abutting step of the through hole is attached to the engagement holding member of the to-be-extracted stay. Releases engagement with the engaging portion when it is brought into contact with the holding step portion The movable platen is provided with a stay clamp means that can be gripped so that at least the stay to be extracted can be integrally moved with the movable platen. The stay clamp means grips at least the stay to be removed, and the mold opening / closing means temporarily moves the movable platen together with the mold clamping means in the mold closing direction, thereby allowing the stay to pass through the abutting step portion of the stay and the fixed platen. The stay is shifted in the mold closing direction by the holding gap between the holding step portion of the hole, thereby creating a disengagement gap between the engagement portion of the stay and the engagement holding member, The engaging device of the molding device is characterized in that, after the engagement of the engaging holding member of the stay to be removed is released by the removing means and removed, the stay to be removed is removed from the fixed platen. According to the extraction method of Iba.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 is a schematic side view of an injection molding apparatus showing one embodiment of the present invention, FIG. 2 is a cross-sectional view showing a state in which a fixing plate side mounting portion and a mold clamping unit side mounting portion of a stay are partially omitted, and FIG. FIG. 4 is an enlarged cross-sectional view of the fixed platen side mounting portion of the to-be-extracted stay in the normal molding state, FIG. 4 is also an enlarged cross-sectional view of the fixed platen-side mounting portion of the to-be-extracted stay at the time of extraction, and FIG. FIG. 6 is a cross-sectional view showing an example of a means for removing an engagement holding member, and FIG. 7 is an example of a stay clamp means. FIG.

As shown in FIG. 1, this injection molding apparatus 1
Reference numeral 0 designates a fixing plate 30 fixed on the base 11 and
A mold clamping device 20 serving as a mold clamping unit is provided through the second unit 2. A movable platen 40 is attached to the ram 21 of the mold clamping device 20. The movable platen 40 is slidably held by four stays (tie bars) 50, 50, 50, 50 which are provided between the cylinder plate 22 of the mold clamping device 20 and the fixed platen 30. The mold opening / closing cylinders 60, 60, which are two upper and lower mold opening / closing means provided on the 30, are configured to be able to freely move forward and backward (close and open the mold) with respect to the fixed platen 30. The movable platen 40 is closed or opened by the mold opening / closing cylinder 60, and when the mold is closed, the pressure is increased by the mold clamping device 20 and pressed against the fixed platen 30. In the figure, reference numeral 50A denotes a to-be-extracted stay to be extracted, and in this example, one of the upper stays is the to-be-extracted stay 50A. 1 is an injection device, M is a molding die, M1 is its fixed die, M2
Is a movable type.

Each of the stays 50 (extracting stays 50)
A), as shown in an enlarged view in FIG. 2, an engagement portion 54 is provided in the fixed platen-side attachment portion 51, and is fixed by the engagement of the engagement holding member 70, and is attached to the mold clamping unit side. In the portion 55, a mounting step 56 is provided, and a mounting nut 59 is screwed and fixed to a small-diameter screw portion 57 formed through the step 56. In the present invention, the engaging portion 54 to which the engagement holding member 70 is engaged with the fixing plate side attaching portion 51 and the mold clamping means side attaching portion 55
Is formed as a stay main body portion 58 having a constant length L.

In each of the stays 50, an engagement holding member 70 is engaged with the engaging portion 54 of the fixed platen side mounting portion 51, and a mounting nut 59 is attached to the mounting step 56 of the mold clamping means side mounting portion 55. The fixed length L of the stay body 58 between the fixed platen 30 and the mold clamping means 20 is made by screwing and stopping.
Can be reliably ensured. The mounting step 56
Although not shown, it may be formed by attaching a collar or the like to the stay main body 58.

As shown in FIG. 3, at least the stay 50A to be pulled out of the stay 50 is fixed to the fixed platen 3 as shown in FIG.
0 has an abutting step 52 that abuts a holding step 32 formed inside the through hole 31, and the abutting step 52 slightly holds the holding step 32 of the through hole 31. It is penetrated and held while maintaining the gap S. Numeral 33 in the figure is a small diameter portion of the through hole,
53 represents a stay small diameter portion. The small holding gap S is an insertion gap for engaging or disengaging the engaging portion 54 of the stay 50A (or 50) with the engagement holding member 70 described below, and is about 0.5 mm here. Is set to In this embodiment, for the sake of manufacturing, all the stays 50 including the to-be-extracted stays 50A are provided with the abutment step portions 52, and the through-holes are held while keeping the holding gap S. May be held through a normal through hole and a nut without providing the abutment step 52 and the holding gap S.

As described above, each of the stays 50A has the engagement holding member 70 engaged and attached to the engagement portion 54 outside the through hole 31 of the fixed board 30. Stay 50
Is, for example, a plurality of saw blade grooves 54 as shown in the figure.
The engagement protrusion 73 of the engagement holding member 70 meshes and is engaged. Note that half nuts 71 and 72 are usually used as the engagement holding member 70.

The stay 50 is attached by the engagement holding member 70 and attached to the fixed platen 30. The stay 50A to be extracted is shown in FIGS.
As shown in the figure, when the abutting step 52 is abutted against the holding step 32 of the through hole 31, there is provided a detaching means 80 capable of releasing the engagement with the engaging portion 54. . As shown in FIG. 6, the detaching means 80 of the engaging and holding member 70 of the embodiment comprises a cylinder device 81, the cylinder arm 82 of which is fixed to the inner half nut 71, and the inner half nut 71 of the cylinder device main body 81A. Connecting arm 8 which penetrates nut 71 and is connected and fixed to outer half nut 72
The inner half nut 71 is provided by the expansion and contraction of the cylinder arm 82 accompanying the operation of the cylinder device 81.
The outer half nut 72 approaches (when the arm is extended) and separates (when the arm is shortened) along the sliding groove 76 of the nut mounting member 75. Incidentally, the detaching means 80 may be a clamp structure by tightening and loosening the most common bolts. Further, the stay 50 other than the to-be-extracted stay 50A may have the same structure.

Next, a description will be given of the movable plate 40. At least a portion of the movable plate 40 through which the to-be-extracted stay 50A is inserted is such that the stay 50A and the movable plate 40 can be integrally moved as shown in FIG. Is provided with stay clamp means 90 capable of holding the stay freely. As the stay clamp means 90 of this embodiment, a so-called split nut type clamp device as shown in FIG. 7 is used. One of the two split nut portions 91 and 92 is supported by a shaft 93, and the other split groove portion 94 is tightened and loosened by a tightening bolt 95. Reference numeral 96 in FIG. 7 denotes a braking member (brake shoe) made of a packing material or the like for ensuring grip of the to-be-extracted stay 50A, and 97 denotes a connection bolt to the movable plate 40.

The stay clamp means 90 is for grasping the to-be-extracted stay 50A and moving integrally with the movable platen 40. In particular, as set forth in the second aspect of the present invention, the stay clamp means 90 is provided. It is preferable that 90 be provided on the stay 50A to be extracted and on the stay 50 substantially diagonally opposite to the stay 50A (with respect to the center of the mold clamping device).

Next, a method of extracting a tie bar in the molding apparatus according to the present invention will be described. In this extracting method, the above-described structure is used as it is. That is,
Mold clamping means (mold clamping device) 20 for pressing the movable platen 40 against the fixed platen 30; and mold opening / closing means (mold opening / closing cylinder) installed on the fixed platen 30 to move the movable platen 40 relative to the fixed platen 30 ) 60, and a plurality of stays 50, 50, 50, 50 provided between the fixed platen 30 and the mold clamping means 20 for sliding the movable platen 40. Each of the stays 50 has a fixed length L between an engagement portion 54 to which the engagement holding member 70 of the fixed platen attachment portion 51 is engaged and an attachment step 56 formed on the mold clamping means attachment portion 55. At least the stay 50A to be pulled out of the stays has an abutment step 52 that abuts a holding step 32 formed inside the through hole 31 of the fixing plate 30; The abutting step 52 is formed by the holding step 3 of the through hole 31. And are slightly through keeping the holding gap S maintained, the the engagement holding member 70 of the extraction stay 50A, the said abutment step portion 52 through hole 31
A detaching means 80 capable of releasing the engagement with the engaging portion 54 when the retaining plate 32 is brought into contact with the holding step portion 32 is provided. A stay clamp means 90 that can be gripped so as to be able to move integrally with the movable plate 40 is provided.

In the method of the present invention, at the time of extraction, first, at least the stay 50A to be extracted is gripped by the stay clamp means 90 and the mold opening / closing means 6 is opened.
0, the movable platen 40 is once moved in the mold closing direction together with the mold clamping means 20 to hold the movable platen 40 between the abutting step 52 of the stay 50A and the holding step 32 of the through hole 31 of the fixed platen 30. The stay 50A is shifted in the mold closing direction by the gap S. As shown in FIG. 4, the disengagement gap T is created between the engaging portion 54 of the stay 50A and the engagement holding member 70 by the shift movement of the extracted stay 50A. Next, after the engagement of the engagement holding member 70 of the to-be-extracted stay 50A is released by the detaching means 80 and detached, the to-be-extracted stay 50A is removed from the fixed platen 30.

As described above, when the stay 50A moves in the mold closing direction, the holding gap S moves to the front end of the stay 50A, and the gap between the engaging portion 54 and the engagement holding member 70 is moved. In this case, the engagement release gap T is formed, whereby the engagement between the engaging portion 54 of the stay 50A to be extracted and the engagement holding member 70 can be easily released.

After the extraction has been completed and the mold changing operation has been completed, when the to-be-extracted stay 50A is to be mounted on the fixed platen 30 again, the fixing plate-side mounting portion 51 of the to-be-extracted stay 50A must be inserted through the fixed platen 30. Insert into hole 31,
The engagement holding member 70 is engaged with the engagement portion 54 on the outside thereof. When the mold is closed and the mold clamping device 20 is advanced to perform mold clamping, the stays 50 provided between the mold clamping device 20 and the fixed platen 30 are connected to each other as described above. Since the distance between the attaching portion 54 and the mounting step 56 is a constant length L, the mold clamping device 20 slightly moved to the fixed platen 30 side at the time of extraction in order to maintain the constant length L is used. Return to the position. This eliminates the dimensional difference between the stay 50A and the other stays 50 which may occur when the stay 50A is pulled out, and completely parallels the fixed platen 30 and the mold clamping device 20 during molding. You can keep the degree.

[0023]

As shown and described above, according to the present invention, the engagement between the engaging portion of the stay to be extracted and the engaging portion of the engaging and holding member of the fixed plate can be easily released. In addition, eliminating the dimensional difference between the stay to be extracted and the other stays that may occur at the time of extraction, ensuring the secure parallelism between the fixed platen and the mold clamping device, eliminating stress concentration on a specific stay, High-precision molding can be performed.

[Brief description of the drawings]

FIG. 1 is a schematic side view of an injection molding apparatus showing one embodiment of the present invention.

FIG. 2 is a cross-sectional view in which a part of a state of a fixing plate side mounting portion and a mold clamping unit side mounting portion of a stay is omitted.

FIG. 3 is an enlarged cross-sectional view of a fixing plate-side mounting portion of a removal stay in a normal molding state.

FIG. 4 is an enlarged cross-sectional view of a fixing plate side mounting portion of a stay to be extracted at the time of extraction.

FIG. 5 is a cross-sectional view of a main part in which the displacement of the stay to be extracted at the fixed platen side mounting portion is compared in a vertically different state.

FIG. 6 is a cross-sectional view illustrating an example of a unit for removing an engagement holding member.

FIG. 7 is a cross-sectional view illustrating an example of a stay clamp unit.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Injection molding apparatus 20 Mold clamping means (clamping apparatus) 30 Fixed plate 31 Through hole 32 Holding step portion 40 Movable plate 50 Stay 50A Extracting stay 51 Fixed plate side mounting portion 52 Abutment step portion 54 Engagement portion 55 Mold clamping Device side mounting portion 56 Mounting step portion 58 Stay body portion 60 Mold opening / closing means 70 Engagement holding member 80 Removal means 90 Stay clamp means S Holding gap T Disengagement gap L A fixed length of the stay body

Claims (3)

(57) [Claims] 1. A mold clamping means for pressing a movable plate against a fixed plate, a mold opening / closing device installed on the fixed plate to move the movable plate with respect to the fixed plate, and the fixed plate and the mold clamping device. And a plurality of stays for the movable platen to slide between the stays, wherein each of the stays includes an engagement portion to which an engagement holding member of the fixed platen-side attachment portion is engaged. A gap between the mounting step formed on the mold clamping means side mounting section is configured to have a fixed length, and at least in the stay to be removed, of the stays, a holding step formed inside the through hole of the fixed platen. Abutment step which abuts with the holding step of the through-hole with a slight holding gap kept therebetween. When the abutment step is brought into contact with the holding step of the through hole, the member A detaching means capable of releasing the engagement with the engaging portion is provided, and the movable platen is provided with a stake that can be gripped so that at least the extracted stay can be integrally moved with the movable platen. A tie bar extraction structure for a molding apparatus, wherein a ramp means is provided. 2. A tie bar extracting structure according to claim 1, wherein said stay clamping means is provided on a stay to be extracted and a stay substantially diagonally positioned with respect to said stay to be extracted. 3. A mold clamping means for pressing the movable plate against the fixed plate, a mold opening / closing device installed on the fixed plate to move the movable plate toward and away from the fixed plate, the fixed plate and the mold clamp means. And a plurality of stays that are erected between the movable platen and the movable platen, and wherein the stays are extracted by a molding device having a plurality of stays for sliding the movable platen. A fixed length is formed between the engaging portion to be attached and the mounting step formed on the mold clamping means side mounting portion, and at least in the stay to be removed among the stays, the inside of the through hole of the fixing plate is provided. An abutting step that abuts the formed holding step, and the abutting step is held through the holding step of the through-hole with a slight holding gap therebetween, and The abutment step is provided on the engagement holding member of the extraction stay through the through hole. Removing means capable of releasing the engagement between the engaging portion is provided when brought into abutment to the holding stepped portion of the bore,
The movable platen is provided with a stay clamp means that can be gripped at least so that the to-be-extracted stay can be moved integrally with the movable platen.At the time of extraction, at least the to-be-extracted stay is removed by the stay clamp means. The movable gap is once moved in the mold closing direction together with the mold clamping means by gripping and the mold opening / closing means, and the holding gap between the abutting step of the stay and the holding step of the through hole of the fixed board is held. The stay is displaced in the mold closing direction by an amount, thereby creating a disengagement gap between the engagement portion of the stay and its engagement holding member,
A method for removing a tie bar of a molding apparatus, comprising: releasing the engagement of the engaging holding member of the removal stay by the removal means and removing the stay; and removing the removal stay from the fixed platen.