JPS6012215B2 - Bush manufacturing method and device - Google Patents

Description

[Detailed description of the invention]

The present invention relates to a method and apparatus for manufacturing a bush having protrusions intermittently in the longitudinal direction. 2. Description of the Related Art Conventionally, for example, when passing an electric wire through a hole in a cabinet or panel, a synthetic resin bush 1 as shown in FIGS. 1 to 3 has been used. The bush 1 has a large number of teeth 3 protruding in rows at regular intervals on both widthwise edges of one side of a long band 2, and a longitudinal groove 4 is formed between the rows of teeth 3 on both sides. It is something. This push can be cut and bent depending on the purpose, but
In order to reduce product loss, long products are required. Such a bush 1 has conventionally been manufactured by injection molding, but it has the following problems.

[1}
Molding long objects requires a large mold, which increases manufacturing costs. '21 It takes time and effort to process a mold with uneven parts corresponding to the peaks or teeth of a molded product. [3- In long products, welding occurs and strength decreases becomes a problem. [4- In injection molding, the length of the molded product is limited to, for example, 500 sails, and furthermore, the loss of raw material resin at the runner gate cannot be avoided. The present invention is intended to eliminate the above-mentioned drawbacks of molded products having intermittent protrusions in the longitudinal direction by injection molding, and to produce bushings in large quantities using an extruder, rotating rolls, and slitting device. It is designed to be continuously molded. Note that polyacetal, polypropylene, polyamide, fluororesin, etc. are used as materials for the bushing, etc., but polyamide is often used due to its strength, abrasion resistance, etc. Next, the present invention will be explained with reference to an embodiment shown in the drawings. hopper for supplying resin material; 7 is a screw; 8 is a die connected to the extruder 5; 9 is a resin passage through which the molten resin flows down in the die 8; 1) a wedge provided at the bottom of the die 8; 11' is a rear die provided at the bottom of the die 8, 12 is a pattern roll rotatably provided close to the wedge-shaped die 10', and 13 is a pattern roll for rotating the molten resin with the wedge-shaped die 10. The material is discharged from between the circumferential surfaces of the pattern roll 12 in a state where it is wound around the circumferential surface of the pattern roll 12, solidified on the pattern roll 12, and then sent out from the pattern roll 2 in the longitudinal direction. A series of molded products 14 having intermittent protrusions are used to slit the bushes 1, which are part of the molded product 13 fed out from the pattern roll 12, in the feeding direction to separate them into a plurality of bushes. The slitting device 15 is a guide roll for the molded product 13 and the bushing, and i6 is a belt-driven take-off machine. A wedge-shaped die 10 and a rear die 11 are installed to face each other, as shown in FIG. Thus, a gap d is provided between the lower end 11a of the rear die 11 on the resin passage 9 side and the circumferential surface of the pattern roll 12. It acts as an escape route for the molten resin associated with ~preventing variations in the dimensions and density of the molded part, and greatly helps eliminate the need for molding operations to be conducted under strict extrusion pressure control. In order to obtain a molded product with good dimensional accuracy and uniform density, in FIG.
The angle formed by the straight line connecting [] and the inclined surface 10a is 8, the distance between the upper end IQd of the inclined surface turtle oa and the upper surface of the pattern roll 12 is do, and the lower end 11a of the rear die 11 and the pattern When the distance between the roll turtle 2 and the top surface is d, 9
00mi8SI200 and 1. I made it meet the conditions for 5th Misaki. As mentioned above, the present invention uses a wedge-shaped passageway that is open on the back side of the die and is not pressure-sealed, thereby effectively combining the fluid wedge effect and the effect of the bank, which is a pool of molten resin. . That is, due to the fluid wedge effect caused by the wedge-shaped die 101, the molten resin can be reliably and easily pushed into the patterned portion of the patterned roll 12, and moreover, the lower end of the rear die blade and the circumferential surface of the patterned roll 12 are Since the die is not pressure-sealed by providing an appropriate gap d therebetween, it is less susceptible to pressure fluctuations caused by the extruder 5, and fluctuations in the thickness of the molded product can also be reduced. In addition, since the space between the rear die 11 and the pattern roll 12 is open, the degassing effect due to the rotation of the bank, which is a pool of molten resin, works effectively, and the pattern roll 12 is not required to be vented. However, the lower end of the rear die 1 and the pattern roll 1 can be degassed.
If the distance d between the upper surface of the die 2 and the upper surface of the die 2 is large, the molten resin will flow back into the rear die 11. As a result of various experiments conducted by the inventors of the present invention, as mentioned above, 1. Only when the SdSdoS5 sail is used, there is no backflow to the rear die 11, and sufficient degassing is achieved by bank rotation, and the molded product is There was no variation in wall thickness, and the degree of transfer of the uneven pattern of the patterned roll 12, that is, the molding condition of the corners of the molded product was also good. The holding portion of the pattern roll 12 had a structure as shown in FIGS. 13 and 14. The roll shafts 23 on both sides of the pattern roll 12 are rotatably attached to the tip of a swinging arm 25 via bearings 24, and the lower end of the swinging arm 25 is attached to a rotating shaft 26.
The rotating shaft 26 was rotatably attached to a frame 28 via bearings 27 at both ends of the rotating shaft 26 . Between the chain wheel 30 of the electric motor 29 that has been lost to the bottom slope of the frame 28 and the chain wheel 31 attached to the rotating shaft 26, and between the chain wheel 31 and the chain wheel 32 attached to the roll shaft 23, Endless chains 33 and 34 are wound around each, and the pattern roll 12 is rotated by the operation of an electric motor 29. The rotation speed of the electric motor 29 can be changed as appropriate by operating a handle 29a. A bracket 35 is provided on a part of the swinging arm 25, a bracket 36 is provided on a part of the frame 28, and a bolt-shaped shaft 38 with a handle 37 is provided on the bracket 36.
is rotatably attached with a screw, the tip of the ball 38 passes through the bracket 35, and the tip of the shaft 38 can be fixed to the bracket 35 by two nuts 39 placed with the placket 35 sandwiched between them. . Then, by turning the handle 37 with the nut 39 loosened, the swinging arm 25 is swung about the rotating shaft 26, and the horizontal position of the pattern roll 12 is appropriately adjusted and fixed at that position. I tried to make it wet. Brackets 40 provided at each corner of the lower end of the frame 28 are received by vertical screw shafts 42 rotatably provided on bearings 41 on the floor, and a chain wheel 43 is fixed to each screw shaft 42. An endless chain 44 is wound around the chain wheel 43, and by rotating the chain 44 and the chain wheel 43, the entire frame 28 is moved up and down.
The vertical position of can be adjusted as appropriate. The chain 44 and the chain wheel 43 may be rotated by the operation of an electric motor (not shown), or the chain wheel 4
You may also turn 3 manually with a spanner or the like. In this way, by appropriately adjusting the vertical and horizontal positions of the pattern roll 12, the pattern roll 12 and the wedge-shaped die 10 can be adjusted.
The interval between the two can now be adjusted as appropriate.
14 is a slitting device in which a large number of knives 14a are arranged at appropriate intervals in the direction of the marlin; 15 is a guide roll;
1'5a is a bearing for the guide roll 15. As shown in FIG. 5, an inclined surface 10a is provided on the inside of the wedge-shaped die 10 facing the pattern roll 12, and as shown in FIG. Several parallel grooves 10b were provided at regular intervals. The lower end 10c of the wedge-shaped die 10 was placed at a position with an extremely small gap t between it and the surface of the pattern roll 12. Reference numeral 17 indicated by a chain line in FIG. 5 is a side plate for the die 8 for regulating the width of the molded product 13. In addition, side plate 1
As shown in FIG. 14, the lower end of the pattern roll 12
It may also be positioned in a groove 12a provided on the circumferential surface of. As shown in FIGS. 7 to 9, the pattern roll 12 is
There are two types of discs: a disc 19 with cutouts 18 for forming the three teeth of the pusher 1 at regular intervals on its circumferential surface, and a disc with different thicknesses that does not have any cutouts 18 on its circumferential surface. 20,
No. 21 were lined up alternately in close contact with each other in the axial direction, and the silk was stood up. In addition, 22 is a roll weaving part located at both ends, and the outer diameters of the disks 20 and 21 without the notch part 18 and the roll weaving part 22 located at both ends were all the same. That is, as shown in FIG. 7, the pattern roll 12 includes a roll portion 22, a disk 19 with a cutout 18, and a thick disk 20 without a cutout 18.
, a disc 19 with a notch 18, a thin disc 21 without a notch 18, a disc 19 with a notch 18, a thick disc 20 without a notch 18, ... without a notch 18 The thick disk 20, the disk 19 with the notch 18, and the roll end 22 were arranged in close contact with each other in this order, and attached to the roll shaft 23 as shown in FIGS. 5 and 15. The pattern roll 12 preferably has a hollow structure, and the roll surface temperature can be controlled by circulating water or oil at a constant temperature. FIG. 15 shows an overall assembly diagram of the pattern roll 12. A disk-shaped roll end portion 22 and disks 19, 20, 2 are provided on the outer periphery of the roll base portion 45 that is integrated with the roll shaft 23 portion.
1 were arranged one after another as described above, and they were fixed in close contact with each other using the side plates 46 or bolts 47 screwed to the side plates 46 from both sides. The side plate 46 was fixed to the side surface of the roll base portion 45 with bolts 48. 49 is disk 1
9, 20, 21, etc. are positioning bars that pass through the disks 19, 20, 21, the roll end 22, and the side plate 46 so that the positions do not shift in the circumferential direction. The interior of the pattern roll 12 is hollow, and the roll base portion 45
A temperature control room 50 is provided along the circumferential inner surface of the temperature control room 50, and cooling water, hot soot, etc. are fed into the control room 50 from one end of the roll shaft 23, and are discharged from the pool end of the roll shaft 23, as described above. The roll surface temperature can be appropriately controlled. Note that a rotary joint and a flexible hose (not shown) were attached to both ends of the roll shaft 23 and connected to a water supply source, a drainage tank, etc., respectively. The several grooves 10b of the wedge-shaped die 10 and the pattern roll 12 were positioned in the axial direction as shown in FIG. The gap t between the inclined surface 10a of the wedge-shaped die 10 and the surface of the pattern roll 12 is made as small as possible to facilitate slitting of the molded product 13. When manufacturing the bush 1, resin molding material is supplied from a hopper 6 at the rear end of the extruder 5 shown in FIG. At this time, the resin material is in a molten state and flows down from the resin passage 9 of the die 8, passes through the gap between the wedge-shaped die 10 and the rear die 11, and is extruded onto the circumferential surface of the pattern roll 12. The resin extruded from the resin passage 9 of the die 8 is guided between the inner inclined surface 10a of the wedge-shaped die 10 shown in FIG. Due to the extrusion force generated by the rotation, it is pressed against the inclined surface 10a and the groove 10b of the wedge-shaped die 10, and is also pushed into the notch 18 formed in the circumferential surface of the pattern roll 12 shown in FIG. The molded products 1 are then cooled and solidified and taken out as a series of molded products 13 having cross-sectional shapes as shown in FIG.
3 is taken up by the take-up machine 16 shown in FIG. Continuously manufacture the bush 1. Furthermore,
As a resin material, for example, nylon 6 (number average molecular weight =
22,000, melting point 215qo), die 8
The temperature of the resin on the part was set at 260 pm, and the surface temperature of the pattern roll 12 was set at 140 q0. Considering the gap t between the wedge-shaped die 10 and the pattern roll 12, the dimensions of the groove 10b of the wedge-shaped die 10 and each disc 19 to of the pattern roll 12 are determined.
It is necessary to determine the dimensions of 21 and the notch 18. According to the present invention, it is possible to mold the bush 1 using materials such as polyacetal, polyethylene, polypropylene, and fluororesin in addition to polyamide. In the above embodiment, as shown in FIG. 10, a groove 10b is provided in the inclined surface 10a of the wedge-shaped die 10, and the two types of discs 20 and 21 without the notch 18 have the same outer diameter. However, as shown for example in FIG.
The two types of disks 20 and 21 without a hole may have different outer diameters. Note that although the intervals between the pros and cons 18 of the disc 19 are often set at a constant pitch, it is also possible to vary the intervals as appropriate on one disc 19. As described above, in the present invention, since the structure as described in the claims is adopted, it is possible to reliably and easily continuously press the largest object having intermittent protrusions in the longitudinal direction. In addition, the patterned roll was made by stacking a disc without a notch and a disc with a notch that matched the shape of the teeth, making it extremely easy to manufacture the patterned roll. Bushes with many tall teeth can also be easily manufactured. Even if the inner width, outer width, tooth height, shape, etc. of a molded product such as a bush that has a protrusion on one side are different, a disc with a notch or a disc without a notch can be used as appropriate. Molded products of various sizes and shapes can be reliably and easily obtained simply by reassembling them into different sizes and shapes, and even molded products of different widths etc. can be molded at once depending on the combination of discs. can do. Further, in the present invention, a wedge-shaped die and a rear die are provided at the lower part of the die, and an appropriate distance is provided between the lower end of the rear die and the circumferential surface of the pattern roll. Since it is molded, the fluid wedge effect allows the molten resin to be pushed into the pattern roll well, is less affected by fluctuations in extrusion pressure, there is no variation in the wall thickness of the molded product, and the molten resin is well degassed. The molding condition of the corners of the molded product is also good, and the product is of good quality. can be easily obtained. Furthermore, in the present invention, a patterned roll is used which is formed by alternately arranging several discs with cutouts on the circumferential surface at desired intervals and discs with no cutouts on the circumferential surface in the axial direction. Several bushes are obtained by molding products with the same cross-sectional shape from a patterned roll so that they are fed out sideways, and by slitting the horizontal joints of the molded products in the feeding direction. Therefore, bushes can be easily manufactured in large quantities.

[Brief explanation of the drawing]

Figures 1 to 3 show one example of a bush manufactured according to the present invention, with Figure 1 being a perspective view, Figure 2 being a side view, and Figure 3 being a side view.
The figure is a front view. Figures 4 to 10 show one of the apparatuses used to carry out the method of the invention.
4 is a schematic configuration diagram explaining the whole, FIG. 5 is a cross-sectional view of the die portion, and FIG.
Figure 7 is an enlarged cross-sectional view along the skin line in Figure 5, Figure 8 is a cross-sectional view along the line of the field in Figure 7, and Figure 9 is a cross-sectional view taken along the line K-X in Figure 7. Figure 10 is an enlarged sectional view taken along the line X-X of Figure 5, Figure 11 is a front view showing one example of a molded product, and Figure 12 shows another example of the part shown in Figure 10. 13 and 14 are a side view and a front view, respectively, showing details of the holding part of the pattern roll used in carrying out the method of the present invention, and FIG. 15 is a front view (top view) of the pattern roll. This is a diagram showing a half) and a longitudinal section (lower half).1...Bush
3...Teeth, 5...Extruder, 8...Die, 10...Wedge-shaped die, 10b...Groove, 11...Rear die, 1
2... Pattern roll, 13... Molded product, 14
...Slitting device, 16... Taking machine, 1
8... Notch, 19-21... Disk,
22... Roll end, 23... Roll shaft,
25... Swinging arm, 28... Frame, 29
......Electric motor, 45...Roll base portion, 46
...Side board, 50...Steel greenhouse. Figure 1 Figure 2 Figure 3 *Mu Figure 5 Figure 6 Scales 7 Figure 8 Figure 9 Figure 10 *Mai Carp Figure Ushio 2 Box Number '1 Kō-'4 Gu *15 Kō

Claims (1)

[Claims] 1. A wedge-shaped die and a rear die are provided facing each other at the bottom of a die body through which molten resin supplied from an extruder flows down, and notches are provided at desired intervals on the circumferential surface. A pattern roll formed by alternately arranging several discs having a cutout and a disc having no notch on the circumferential surface in the axial direction is rotatably provided adjacent to the wedge-shaped die, and is connected to the lower end of the rear die. Using a device with a gap of 1 to 50 mm between the circumferential surface of the patterned roll, the resin supplied from the extruder is rotated from between the wedge-shaped die and the circumferential surface of the patterned roll. A method for producing bushes, in which several bushes are obtained by discharging a molded product wound around a patterned roll and slitting a part of the molded product fed from the patterned roll in the feeding direction. 2. A wedge-shaped die and a rear die are provided facing each other at the lower part of the die body through which the molten resin supplied from the extruder flows down, and a pattern roll is provided that rotates in close proximity to the wedge-shaped die. is formed by arranging several disks with cutouts at desired intervals on the circumferential surface and disks without cutouts on the circumferential surface alternately in the axial direction. A bush manufacturing device that has a gap of 1 to 50 mm between the pattern roll and the circumferential surface, and is equipped with a slitting device and a take-up machine after the pattern roll.