JP2883978B2 - Air nipper for gate processing of molded products - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air nipper for gate processing of a molded article used for cutting a runner of a resin molded article at a product side gate.

[0002]

2. Description of the Related Art An air nipper for gate processing of this kind is configured to firstly rotate a pair of nipper blades which are rotatably opened / closed in advance in a cutting operation for driving the pair of nipper blades in a direction of closing the blade edges. It must be moved to the gated position of the part.

Therefore, conventionally, a cylinder device for moving the nipper blade to a predetermined position has been provided separately from a cylinder device for driving the nipper blade for cutting. However, this air nipper has two cylinder devices that perform different operations, and it is necessary to supply air to each of the cylinder devices according to the operation timing, and the configuration is complicated and the size of the device is increased. There was a point.

[0004] Therefore, as disclosed in Japanese Utility Model Publication No. Hei 7-26090, there has been invented an apparatus in which the above operation is continuously performed by one cylinder device. This is shown in FIG.
As shown in the sectional view of FIG. 7 and the bottom view of FIG. 7, the nipper blade body 21 moves in the axial direction following the piston 22 of the cylinder device 20 which drives the nipper blade body 21 in the direction of closing the cutting edge 21a. Output rod 23 is connected to cylinder 24
A substantially L-shaped operating lever 26 which engages with the output rod 23 is pivotally mounted on a bracket 25 which is provided so as to protrude from a long hole 24a formed on the bottom surface of the cylinder and which movably holds the cylinder device 20 in the axial direction. Further, one side of this operating lever 26 is brought into contact with a contact plate 27 fixed to the cylinder 24, and the piston 22 for driving the nipper blade body 21 is moved, and 24
The cutter itself is pushed through the output rod 23, the operating lever 26, and the abutment plate 27 to move the nipper blade 21 pivotally attached to one side of the cylinder 24 in the lateral direction (the axial direction of the cylinder). Things.

[0005]

The above-mentioned conventional air nipper for gate processing, which has the former two cylinder devices, has a problem that the structure is complicated and the device becomes large as described above. .

In the latter Japanese Utility Model Publication No. Hei 7-26090, the movement and closing operation of the nipper blade can be continuously performed by one cylinder device, so that the device can be downsized and the air can be reduced. Although it is not necessary to measure the supply timing of the cylinder, an elongated hole is provided on the bottom of the cylinder, an output rod is attached to the piston through this elongated hole, and the output rod is attached to the bracket that slidably holds the cylinder. An operating lever that is rotated in contact with it must be pivotally mounted, and a contact plate that this operating lever abuts must be mounted between the bracket and the outside of the cylinder. However, there is a problem that the assembly is difficult.

An object of the present invention is to solve the problems of the conventional gate processing air nipper.

[0008]

In order to solve the above-mentioned problems, the present invention according to claim 1 of the present invention provides a piston having a tapered surface at the tip and a slidable piston. A tightly fitted cylinder, a pair of nipper blades pivotally attached to the tip side of the cylinder and driven in the direction of closing the blade edge by sliding contact with the tapered surface, and holding the cylinder slidably in the axial direction thereof. In an air nipper for gate processing of a molded product having a bracket and a spring for urging the piston in a direction for returning the piston to its original state, a small-diameter sub-cylinder portion is recessed at the rear of the piston, and the cylinder is provided with the cylinder. A sub-piston having a piston rod penetrating through the rear wall is airtightly fitted, and a spring for biasing the sub-piston with the rear wall of the cylinder toward the distal end of the piston is provided. The biasing force of the spring, set smaller than the urging force of the spring for the piston return, which is furnished to the cylinder. Further, the bracket is vertically bent upward at a rear portion of the cylinder, and a rear end of the piston rod is attached to the bent vertical portion.

According to a second aspect of the present invention, in the air nipper for gate processing of a molded product according to the first aspect, the piston rod penetrates a vertical portion of the bracket and is slidably attached to the vertical portion. A spring is provided on the rear end side of the piston rod protruding from the portion to bias the piston rod rearward of the vertical portion.

[0010]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on the illustrated embodiments.

FIG. 1 is a front view showing an embodiment of an air nipper for gate processing of a molded product according to the present invention, and FIG.
FIG. 4 is a cross-sectional view taken along a line A. As shown, the air nipper for gate processing mainly includes a piston 1 and a piston 1
Slidably fitted in a cylinder 2, a substantially L-shaped bracket 3 in side view holding the cylinder 2 slidably in its axial direction (left-right direction in FIG. 2), and a pivot It is constituted by a pair of nipper blade bodies 4 and 4 attached.

As shown in the plan view of FIG. 5, the piston 1 has a distal end (lower side in FIG. 5) recessed in an inverted V or U-shape, and the inner surfaces thereof are tapered surfaces 1a inclined toward each other. , A sub-cylinder portion 1b is recessed at the rear (upper side in FIG. 5).
A sub-piston 5 having a piston rod 5a is hermetically inserted into b. A predetermined position near the rear end of the piston rod 5a is provided with a C-shaped washer fitting groove 5 to be described later.
b, 5c are provided. Note that in FIG.
Denotes a through-hole for venting air provided in front of the sub-cylinder portion 1b, and 16 denotes a seal member for keeping airtightness between the cylinder 2 and the cylinder 2 tightly fitted.

The cylinder 2 has a tip (left side in FIG. 2)
A pair of nipper blades 4 and 4 are mounted above the opening 2a so that the lower half faces the opening 2a, and the rear end is a rear wall. It is airtightly closed at 9. The rear wall 9 is provided with a through hole 9a through which the piston rod 5a slidably and slidably passes, and an air supply passage 9 communicating with an air chamber 10 in the cylinder 2.
An air supply pipe 9b having a c is provided to protrude rearward. The air supply pipe 9 b is for connecting the external air supply means (not shown) to feed compressed air into the air chamber 10. A spring 6 is provided inside the cylinder 2 to press the piston 1 against the rear side (the right side in FIG. 2) of the cylinder 2 and to return the piston 1 to its original state. Note that in FIG.
Is a seal member for keeping the piston rod 5a and the through hole 9a airtight.

The nipper blade 4 has a cutting blade 4a on one side.
And a driving part 4b is provided on the other side, and a pair of symmetrically formed left and right parts are connected in an X-shape so as to be able to rotate relative to each other as shown in FIG. Thereby, the respective cutting edges 4c, 4c can be driven in the directions of approaching and separating from each other. The left and right operating parts 4b,
4b, a spring 11 is elastically mounted, and the other edge 4
c, 4c are urged in a direction to expand.

The bracket 3 is formed by bending a metal plate into a substantially L-shape as viewed from the side. The cylinder 2 is mounted on the horizontal portion 3a, and a longitudinal slot provided in the horizontal portion 3a is provided. The cylinder 2 is slidably held in the axial direction (the left-right direction in FIG. 2) by attaching the screw 13 to the lower surface of the cylinder 2 through the through hole 3c. The vertical portion 3b located behind the cylinder 2 is provided with a through hole 3e through which the piston rod 5a passes and a through hole 3d through which the air supply pipe 9b passes.

The air nipper for gate processing of a molded product according to the present invention comprising the above members is provided with a pair of nipper blades 4 and 4 mounted on a front upper side of a cylinder 2 so as to be rotatable about a shaft 12. 2 with a spring 6 interposed in the piston 1
Is inserted, a sub-piston 5 and a spring 7 are inserted into a sub-cylinder 1b formed at the rear of the piston 1, and a rear wall 9 is airtightly attached to the rear of the cylinder 2 to assemble the cylinder. Can be Here, the biasing force of the spring 7 is smaller than the biasing force of the spring 6 for returning the piston 1.

Next, the cylinder 2 assembled in this manner is placed on the horizontal portion 3a of the bracket 3, and the elongated hole 3c
The screw 13 is attached to the lower surface of the cylinder 2 from the outside so as to penetrate the cylinder 2. At this time, the piston rod 5a and the air supply pipe 9b projecting to the rear of the cylinder 2 pass through the through holes 3e and 3d provided in the vertical portion 3b of the bracket 3, respectively. Side is through hole 3
e and 3d are guided by a piston rod 5a and an air supply pipe 9b, and the front side is guided by a screw 13 that penetrates a long hole 3c, and is slidably attached to the bracket 3. In addition, the piston rod 5a protruding from the through hole 3e has an inner portion (the left side in FIG. 2) of the vertical portion 3b.
The C-shaped washer 14 is fitted into the groove 5b, and the spring 8 is inserted into the piston rod 5a outside the vertical portion 3b (rightward in FIG. 2), and the C-shaped washer 15 is similarly fitted into the groove 5c. By doing so, the piston rod 5a is attached to the vertical portion 3b so as not to deviate and slide in a predetermined range.

As described above, the assembly of the air nipper for gate processing of the molded article of the present invention is completed.

The air nipper for gate processing of the molded article of the present invention assembled in this manner is attached to a molded article automatic take-out device (not shown) or the like, and a gate existing between the molded article 30 and the sprue 32 is provided. 31 is cut at the base end side (molded product side), and is used for gate processing of the molded product 30.

Next, the function of the air nipper for gate processing of the molded article of the present invention having the above-mentioned structure will be described.
When the compressed air is sent into the cylinder 0, a force that pushes the piston 1 to the left from the state shown in FIG. . At this time, the cylinder 2 and the piston 1 are urged in opposite directions by a spring 6 so as to resist this movement, but the cylinder 2 has a spring 7 whose rear wall 9 is interposed between the cylinder and the sub-piston 5. When the spring 6 is compressed by air pressure, the cylinder 2 itself first moves rightward. The sub-piston 5 is always held by a spring 8 provided between the sub-piston 5 and the vertical portion 3b of the bracket 3.
Pulled to the right and held.

By the above operation, the nipper member 4 attached to the cylinder 2 is guided toward the gate processing position of the molded product.

When the cylinder 2 is moved in this manner, the rear wall 8 comes into contact with the vertical portion 3b of the bracket 3 and cannot move any more. At this time, the nipper blade 4
Are located at locations where gate processing of the molded product 30 is performed, as shown in FIG. In the above operation,
If the nipper blade body 4 comes into contact with the end surface of the molded product 30 before the rear wall 8 comes into contact with the vertical portion 3b, the spring 8 contracts as the piston 1 is pushed into the cylinder 2 and the sub-piston 5 is moved. By moving into the sub-cylinder 1b of the piston 1, the shock at that time is softened, and the cylinder 2 cannot be moved further.

When compressed air is further fed into the air chamber 10 from this state, the piston 1 moves toward the distal end of the cylinder 2 against the urging force of the spring 6, and the taper protrudes from the opening 2a. The surface 1a comes into contact with the operating portion 4b of the nipper blade body 4. When the piston 1 further moves from this state as shown by a broken line in FIG. 3, the left and right operating portions 4b, 4b of the nipper blade body 4 slide in contact with the tapered surfaces 1a, 1a, respectively, and move in a direction approaching each other. And the other edge 4
c and 4c are closed together. Therefore, the gate 31 of the molded product 30 is sandwiched between the blade portions 4a, 4a of the nipper blade bodies 4, 4, and
You will be cut off.

As described above, the gate 31 of the molded product is
It is cut and processed at its proximal end.

When the cutting of the gate 31 of the molded product is completed in this way, a valve (not shown) is operated to stop the supply of compressed air and open the intake passage 9c to the outside.
Therefore, the piston 1 urged by the spring 6 pushes out the air in the air chamber 10 and moves rightward in the cylinder 2, and the tapered surface 1 a at the tip is separated from the operating portion 4 b of the nipper blade body 4. As a result, the nipper blades 4 and 4
The blades 4c, 4c are returned to the initial state where the blades 4c and 4c are expanded by the urging force.

On the other hand, the tip of the sub-piston 5 comes into contact with the inner part of the sub-cylinder part 1b provided at the rear of the piston 1. This sub-piston 5 has a C-shaped washer 14 attached to a piston rod 5a,
In this state, the movement of the piston 1 is also stopped in such a state that the piston 1 cannot move to the right. Therefore, the biasing force of the spring 6 acts to push the cylinder 2 leftward. At this time, the cylinder 2 is
, The urging force of the spring 7 is
As described above, since the urging force of the piston return spring 6 is smaller than that of the piston 6, the cylinder 2 moves to the left by overcoming the urging force of the spring 7, and returns to the original state shown in FIG. This is to prepare for gate processing.

In the illustrated embodiment, the bracket 3 is mounted on the cylinder 2 with the screw 13 penetrating the long hole 3c. However, the cylinder 2 is slidably mounted on the horizontal portion 3a of the bracket 3. For example, the left and right sides of the horizontal portion 3a of the bracket 3 may be movably sandwiched between flanged rollers or the like.

In the above description, an example is shown in which the piston rod 5a is pulled backward by the spring 8 in consideration of the case where the nipper blade body 4 comes into contact with the end surface of the molded product 30 within a predetermined moving distance. However, in the air nipper for gate processing of a molded product of the present invention, the rear end of the piston rod 5a may be directly fixed to the vertical portion 3b of the bracket 3, and in this case, the nipper blade body 4 is moved to a predetermined position. After that, there is no problem in the operation required for the gate processing of closing the cutting edge.

[0029]

As described above, according to the first aspect of the present invention, the movement of the nipper blade body to the predetermined position and the cutting operation can be continuously performed by one cylinder device. In addition, the size of the device is reduced, and the control of the air supply device is also simplified. Therefore, it is easy to mount the molded article to an automatic unloading device or the like, and it is also possible to perform a gate processing of a fine molded article, which was difficult with a conventional large-sized apparatus using two cylinder devices. Further, since a member such as an operating lever serving as a cam is not required and the structure is simple, the assembling process can be easily performed, and the operation can be performed smoothly and reliably. Therefore, the cost is reduced and the reliability of the device is improved.

According to the second aspect of the invention, the nipper blade body is stopped at the base end side of the gate by elastically holding the cylinder with a spring via a sub-piston. In addition to the effects described above, there is an effect that the gate processing of a resin molded product having an error or variation in dimensions can be performed more reliably.

[Brief description of the drawings]

FIG. 1 is a front view showing an embodiment of an air nipper for gate processing of a molded product according to the present invention.

FIG. 2 is a sectional view taken along line AA of FIG.

FIG. 3 is a cross-sectional view showing a state when the nipper blade body is operated.

FIG. 4 is a front view of the nipper blade body.

FIG. 5 is a plan view of a piston.

FIG. 6 is a sectional view of a conventional example.

FIG. 7 is a bottom view of FIG. 6;

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Piston 1a Tapered surface 1b Subcylinder part 1c Through hole 2 Cylinder 2a Opening part 3 Bracket 3a Horizontal part 3b Vertical part 3c Long hole 3d, 3e Through hole 4 Nipper blade body 4a Blade part 4b Working part 4c Blade tip 5 Sub piston 5a Piston Rods 5b, 5c Grooves 6, 7, 8, 11 Spring 9 Rear wall 9a Through hole 9b Air supply pipe 9c Air supply path 10 Air chamber 12 Axis 13 Screw 14, 15 C-shaped washer 16, 17 Seal member

Continuation of front page (58) Field surveyed (Int. Cl. ⁶ , DB name) B29C 45/26-45/44 B26B 15/00-17/00

Claims (2)

(57) [Claims] 1. A piston provided with a tapered surface at a tip thereof, a cylinder tightly slidably fitted with the piston, and a direction in which a cutting edge is closed by being pivotally connected to the tip side of the cylinder and slidingly contacting the tapered surface. An air nipper for gate processing of a molded product, comprising: a pair of nipper blades driven in the same direction; a bracket holding the cylinder slidably in the axial direction thereof; and a spring for urging the piston in a direction to return to its original state. The piston has a small-diameter sub-cylinder recessed at the rear, and a sub-piston having a piston rod penetrating the rear wall of the cylinder is airtightly fitted into the sub-cylinder, and the sub-piston is fitted with the sub-piston. A spring for biasing the distal end of the piston between the rear wall of the cylinder and the piston is provided, and the biasing force of this spring is the biasing force of the spring for returning the piston contained in the cylinder. Ri small, the bracket is bent vertically upwards at the rear of the cylinder, the gate processing Eanippa of the molded article, characterized in that the rear end of the piston rod is attached to a vertical portion that is the bent. 2. A piston rod penetrates a vertical portion of a bracket and is slidably attached to the vertical portion, and the piston rod is attached to a rear end side of the piston rod penetrating the vertical portion behind the vertical portion. 2. The air nipper for gate processing of a molded product according to claim 1, wherein a biasing spring is provided.