JPH06182829A - Molding of screw and cylindrical cam having unequal pitch - Google Patents

Abstract

PURPOSE:To inexpensively mold a screw and a cylindrical cam both of which have an unequal pitch by eliminating the undercut parts of first-third molds constituting a mold with respect to the grooves of the screw molded at the time of the clamping of the molds. CONSTITUTION:When a fixed mold 17, a movable mold 59 and slide molds 31, 33 are clamped, the shaft 3 temporarily fixed to the movable mold 59 is fixed by the second and third support recessed parts 35, 37 of the slide molds 31, 33 and the first support recessed part 19 of the fixed mold 17. At the same time, the shaft 3 coincides with a screw part 5 by the first molding recessed part 21 of the fixed mold 17, the second and third molding recessed parts 39, 41 of the slide molds 31, 33 and the fourth molding recessed part 63 of the movable mold 59. The molding space having no undercut with respect to the molds 17, 31, 33, 59 and having the shaft 3 arranged therein is formed. By this constitution, a screw and a cylindrical cam having grooves of an unequal pitch provided to the outer peripheries thereof can be produced by one molding work.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of molding a screw and a cylindrical cam made of synthetic resin or metal, in which grooves having unequal pitches are provided on the outer circumference.

[0002]

2. Description of the Related Art For example, in a screw for kneading wheat flour in a noodle making machine or the like, a groove formed around the outer periphery has a wide groove at a portion corresponding to a place where the flour is put. In addition, it is required that the compressed wheat flour be formed at an unequal pitch, which is narrow.

Further, for example, in order to move the driven body engaging with the cam groove in accordance with the rotation of the cylindrical cam at a variable speed, it is necessary to rotate the cam groove at an unequal pitch with respect to the outer peripheral surface of the cylindrical cam. There is.

However, when such a screw and a cylindrical cam are to be injection-molded with synthetic resin or metal, grooves of unequal pitch are undercut to the mold, and therefore a pair of molds are usually used. With the molding method, the mold could not be pulled out from the molded screw and cylindrical cam. For this reason, in the actual molding method, only the screw and the cylindrical cam having the grooves of equal pitch can be molded.

Further, the screw and the cylindrical cam can be manufactured by cutting the outer periphery of a cylindrical material made of synthetic resin or metal to form grooves of unequal pitch. In this manufacturing method, It takes a lot of time for cutting work, which deteriorates the manufacturing efficiency and raises the cost of the product.

The present invention was invented in order to solve the above-mentioned conventional drawbacks, and an object thereof is to provide a screw and a cylinder having grooves of unequal pitch on the outer periphery in one molding operation. It is an object of the present invention to provide a method for forming a screw and a cylindrical cam having an unequal pitch, which can manufacture the cam, improve the manufacturing efficiency, and reduce the cost.

Another object of the present invention is to provide a method for forming a screw and a cylindrical cam having an unequal pitch, which is excellent in mass productivity and can reduce the manufacturing cost.

[0008]

[Means for Solving the Problems]
A method in which a screw having a groove of a predetermined depth around the axis of the outer peripheral surface is laid so as to face in the axial direction at an unequal pitch, is molded by a mold having a molding space that matches the shape of the screw. A mold is composed of at least first to third molds, and when these first to third molds are clamped, it is possible to mold without forming an undercut portion of each mold with respect to a groove of a screw to be molded. Is characterized by.

According to a second aspect of the present invention, there is provided a cylindrical cam in which a cam groove having a predetermined depth is turned around the axis of the outer peripheral surface so as to face the axial direction at an unequal pitch. In the method of molding with a mold, the mold comprises at least first to third molds, and when the first to third molds are clamped, each mold for the cam groove of the cylindrical cam is molded. The feature is that molding is possible without the undercut part of the mold.

[0010]

DESCRIPTION OF THE PREFERRED EMBODIMENTS The method of the present invention will be described below with reference to the drawings.

Claim 1 FIG. 1 is a perspective view showing an outline of a molded screw.

FIG. 2 is a front view of the screw.

FIG. 3 is a sectional view taken along the line III-III of FIG.

The screw 1 is used for kneading the dough put in a kneading machine such as a noodle making machine by compressing it with rotation, and a screw portion made of a synthetic resin around the shaft 3. 5 is integrally molded. Further, the screw portion 5 is provided with a groove 6 having an unequal pitch on the right side shown in FIG. 2, which has a wide interval for allowing the supply of the dough and a narrow interval for compressing the supplied dough. When the screw is molded by a normal molding method, the portion A shown in FIG. 3 is undercut with respect to the mold.

FIG. 4 is a schematic perspective view showing a screw molding die.

FIG. 5 is a sectional view taken along the line VV in FIG.

FIG. 6 is a sectional view taken along line VI-VI in FIG.

Fixed side mounting plate 1 of a molding machine (not shown)
A fixed-side mold plate 13 is attached to 1 via a spacer block 15, and a fixed mold 17 is attached to the center of the spacer block 15.

The fixed mold 17 has a triangular prism shape having a top of about 90 degrees, and is attached so as to extend in the horizontal direction. The fixed mold 17 is provided at its top with a first support recess 19 that corresponds to the four-divided portion of the end of the shaft 3 and a first molding recess 21 that corresponds to the four-divided portion of the screw portion 5.

Mounting blocks 23 and 25 are attached to the fixed-side mold plates 13 located on both sides of the fixed mold 17, and the guide rails 2 are attached to the respective mounting blocks 23 and 25.
7.29 is attached so as to extend in the horizontal direction. Slide dies 31 and 33 are supported on the guide rails 27 and 29 so as to be movable in the horizontal direction.

Each of the slide molds 31 and 33 has a substantially triangular prism shape with a right-angled top, and is formed in a shape corresponding to each slope of the fixed mold 17. And each slide mold 31, 33
2nd and 3rd support recesses 35 and 37 which correspond to the four-divided portions of the end of the shaft 3 and second and third molding recesses 39 and 41 which correspond to the four-divided portions of the screw portion 5 are formed on the top of ing.
In addition, the base end portion (outer side portion) of each slide die 31, 33
The cam holes 43 and 45 having a predetermined inner diameter are formed so as to be inclined toward the fixed-side mold plate 13 so that the intervals gradually increase. Further, taper surfaces 47 and 49 are formed on the outer side surfaces of the slide molds 31 and 33 so that the intervals are widened toward the fixed-side mold plate 13. Recesses 51 and 53 are formed in the mounting blocks 23 and 25, respectively.

On the tie bar 52 of the molding machine, a movable side mounting plate 55 faces the fixed side mounting plate 11 and is supported so as to be movable in the axial direction. The movable side mounting plate 55 has a mold provided on the molding machine. A tightening cylinder (not shown) is connected. Further, a movable side template 57 is attached to the movable side mounting plate 55.

On the movable side mold plate 57 facing the fixed mold 17, a movable mold 59 having a shape substantially matching the fixed mold 17 is attached. Further, a fourth support concave portion 61 corresponding to the four-divided portion of the shaft 3 end portion and a fourth molding concave portion 63 corresponding to the four-divided portion of the screw portion 5 are formed on the top of the movable mold 59.

Rods 65 and 67, which can be inserted into the cam holes 43 and 45 and whose front ends are curved, are inserted into the movable side mold plates 57 located on both sides of the movable mold 59, and the rods 65 and 67 are curved toward each other toward the fixed side mold plate 13. Are installed so that the space between the Also,
Abutting blocks 69 and 71 are attached to the movable side mold plate 57 corresponding to both sides of the rods 65 and 67, respectively, and abutting surfaces 73 and 75 are tapered surfaces 47 and 49 on the inner surface of the corresponding contact blocks 69 and 71. Is formed to match.

Next, a method of molding the screw 1 will be described.

FIG. 7 is a schematic lateral and vertical sectional view showing the mold open state.

FIG. 8 is a horizontal and vertical sectional view of the body showing the molding state.

As shown in FIG. 7, in the mold open state of the movable side mold plate 57 with respect to the fixed side mold plate 13, the slide molds 31 and 33 are located outside of the slopes of the fixed mold 17 outside. . At this time, the rod 65 of the movable-side template 57
67 is the cam hole 43/45 of each slide mold 31/33
The screw 1 is pulled out from the slide mold, and its tip is separated from the slide molds 31 and 33 so that the screw 1 can be taken out.

In the above state, each end of the shaft 3 is locked in the fourth supporting recess 61 of the movable mold 59 or the fourth supporting recess 61 is formed.
After being set by magnetically attracting it by, for example, an attached permanent magnet (not shown), when the movable side mold plate 57 is moved toward the fixed side mold plate 13 as shown in FIG. For each rod 65/67, the movable mold 59 is the fixed mold 17.
Slide molds 31 and 33 as they approach each other
These slide molds 3 are brought into sliding contact with the inside of the cam holes 43 and 45 of
1.33 is brought close to each hypotenuse of the fixed mold 17. The movement of the slide molds 31 and 33 is reinforced by the sliding contact of the contact surfaces 73 and 75 of the contact blocks 69 and 71 with respect to the tapered surfaces 47 and 49.

When the fixed mold 17, the movable mold 59, and the slide molds 31 and 33 are clamped, the movable mold 5 is moved.
The shaft 3 temporarily fixed to 9 is the second one of the slide molds 31 and 33.
And the third support recesses 35 and 37 and the first support recess 19 of the fixed mold 17, and the first molding recess 21 of the fixed mold 17 and the second and third molding recesses of the slide molds 31 and 33. The parts 39 and 41 and the fourth molding recess 63 of the movable mold 59 coincide with the screw portion 5, and each mold 17, 31
There is no undercut for 33 and 59, and a molding space in which the shaft 3 is arranged is formed. In the clamped state, the movement of the slide molds 31 and 33 is restricted by the contact of the contact blocks 69 and 71.

Next, in the above state, when the molten resin is injected from the injection device (not shown) into the molding space, the molds 17, 31, 33, and 33, around the shaft 3, respectively.
The threaded portion 5 having a shape without undercut is integrally molded with the respective molds 17, 31, 33, 59, which coincide with the first to fourth molding recesses 21, 35, 37, 63 of 59.

When the movable side mold plate 57 is separated from the fixed side mold plate 13 after a predetermined curing and cooling time, the movable mold 59 is separated from the fixed mold 17 and the movable side mold plate 13 is separated. With the separating operation of 57, the cam holes 43 and 45
Slide mold 31 with rods 65 and 67 sliding inside
-33 is moved to the outside away from the slope of the fixed mold 17. In addition, since the contact surfaces 73 and 75 of the contact blocks 69 and 71 with respect to the tapered surfaces 47 and 49 of the slide molds 31 and 33 are gradually released as the movable mold plate 57 moves back, The movement of the slide molds 31 and 33 relative to the outside is allowed.

As described above, according to the method of this embodiment, even if the groove 6 of the threaded portion 5 is undercut in the ordinary molding, the groove 6 to be undercut is formed into a plurality of molds 17, 3.
By molding with 1.33, 59, it is possible to mold without the undercut portion. As a result, the screw 1 having the unequal pitch groove 6 which cannot be drawn out by the usual molding method can be molded by one molding operation, which is excellent in mass productivity and reduces the manufacturing cost. You can

The above description has explained the method of molding the screw of the noodle making machine for kneading dough such as wheat flour, but the screw molded by the molding method is not limited to the above-mentioned application, and for example, a screw conveyor. Any screw forming method may be used as in the case of a feed screw, etc., in which grooves are provided around the outer periphery at an unequal pitch in the axial direction.

Claim 2 FIG. 9 is an overall perspective view showing a cylindrical cam.

The cylindrical cam 91 is composed of a support shaft 93 which penetrates the central portion in a state of being prevented from rotating, and a cylindrical cam body 95 integrally formed on the outer peripheral surface of the support shaft 93. Cam grooves 97 having a predetermined depth are formed on the outer peripheral surface of the shaft at unequal pitches in the axial direction.

Similar to the screw 1, the cylindrical cam 91 described above is divided into four parts in a cross section orthogonal to the axis line in which the cam groove 97 of the cylindrical cam 91 does not undercut the mold 4 It is molded using individual molds. Since the detailed description thereof is the same as the method of molding the screw 1 described above, the detailed description thereof will be omitted.

In the above description, the four molds are used so that the groove 6 of the screw 1 and the cam groove 97 of the cylindrical cam 91 can be molded so as not to undercut the respective molds. In the molding method, if the width around the axis that does not cause undercut is large, use three dies that are equally or non-equally divided according to the above width. Conversely, the width around the axis that does not cause undercut is small. in case of,
For example, as shown in FIG.
1. A structure in which two slide dies 107 connected to the fixed die 103 and the cylinder 105 are provided in 1 and two slide dies 115 connected to the movable die 111 and the cylinder 113 are provided on the movable side die plate 109. May be

In the above description, the threaded portion 5 of the screw 1 and the cam body 95 of the cylindrical cam 91 are made of synthetic resin. However, these threaded portion and cam body are die-cast formed using a metal material such as aluminum. Can also be applied to.

[0040]

Therefore, according to the present invention, it is possible to manufacture a screw and a cylindrical cam having grooves of unequal pitch on the outer periphery in a single molding operation, which improves manufacturing efficiency and reduces cost. It is possible to provide a possible method of forming unequal pitch screws and cylindrical cams.

Further, the present invention can provide a method for forming a screw and a cylindrical cam of unequal pitch, which is excellent in mass productivity and can reduce the manufacturing cost.

[Brief description of drawings]

FIG. 1 is a perspective view showing an outline of a molded screw.

FIG. 2 is a front view of a screw.

FIG. 3 is a sectional view taken along the line III-III in FIG.

FIG. 4 is a schematic perspective view showing a screw molding die.

5 is a sectional view taken along line VV in FIG.

FIG. 6 is a sectional view taken along line VI-VI of FIG.

FIG. 7 is a schematic lateral and vertical sectional view showing a mold open state.

FIG. 8 is a schematic lateral and vertical sectional view showing a molded state.

FIG. 9 is an overall perspective view showing a cylindrical cam.

FIG. 10 is a schematic perspective view showing another mold structure for carrying out the present invention.

[Explanation of symbols]

 1 Screw 5 Screw Part 6 Groove 17 Fixed Mold 31 Slide Mold 33 Slide Mold 59 Movable Mold 91 Cylindrical Cam 97 Cam Groove

Claims (2)

[Claims] 1. A molding space in which a screw made of a synthetic resin or a metal, in which grooves of a predetermined depth are turned around the axis of an outer peripheral surface so as to go toward the axial direction at an unequal pitch, matches the shape of the screw. In the method of molding with a mold having
When the above-mentioned mold is composed of at least first to third molds, and when these first to third molds are clamped, it is possible to mold without removing the undercut portion of each mold with respect to the groove of the screw to be molded. A method for forming a screw having an unequal pitch, characterized in that 2. A cylindrical cam made of synthetic resin or metal, in which a cam groove having a predetermined depth is rotated around the axis of the outer peripheral surface so as to face the axial direction at an unequal pitch, and the cylindrical cam coincides with the cylindrical cam. In a method of molding with a mold having a molding space, the mold is composed of at least first to third molds, and
A method for forming a cylindrical cam having an unequal pitch, characterized in that when the third mold is clamped, the undercut portion of each mold with respect to the cam groove of the cylindrical cam to be formed can be eliminated to enable molding.