JPH04351522A - Control method of pipe making device - Google Patents

Abstract

PURPOSE:To provide the control method of a pipe making device capable of preventing the generation of defective products and the trouble of the pipe making device. CONSTITUTION:In a pipe making device 1, in which the periphery of a mandrel 12 is surrounded by a plurality of mold blocks 11 connected in a belt shape and a resin material 4 is extruded in a cavity space 3 formed among the molding blocks 11 and the mandrel 12 while the mold blocks 11 are forwarded and circulated successively and a pipe body 2 is molded, the mold calmping force of the mold blocks 11 changing with the fluctuation of the supply pressure of the resin material 4 is detected with the elapsed time. The circulation velocity of the mold blocks 11 is controlled on the basis of the detected pressure, and clearances among the mold blocks 11 changing with the fluctuation of the supply pressure of the resin material 4 are detected with the lapse of time and the circulation velocity of the mold blocks 11 is controlled on the basis of the detected clearances.

Description

[Detailed description of the invention]

0001

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method of controlling a pipe manufacturing apparatus for manufacturing synthetic resin pipes such as ribbed pipes.

0002

[Prior Art] Generally, a mandrel is surrounded by a plurality of mold blocks connected like a belt, and a resin material is extruded into a cavity space formed between the mold blocks and the mandrel, and the mold blocks are sequentially moved. 2. Description of the Related Art There is known a synthetic resin pipe manufacturing apparatus that is configured to feed and circulate a pipe to form a pipe body.

[0003] Conventionally, when forming a pipe body using this pipe-making apparatus, the circulation speed of the mold block is adjusted at the start of production according to the production conditions, and during operation after the start of production,
It was designed to circulate at a constant speed.

0004

[Problems to be Solved by the Invention] However, the amount of resin material supplied varies from about 1 to 5
It fluctuates slightly within a range of about %. Therefore, when the mold blocks are circulated at a constant speed as in the conventional pipe manufacturing apparatus described above, the following problems occur.

[0005] That is, if the mold block circulates at a circulation speed higher than the circulation speed commensurate with the amount of resin material supplied, the resin material filled into the cavity space will be insufficient, resulting in inconveniences such as not being able to obtain the desired shape and causing product defects. This will occur.

[0006] Furthermore, if the mold block circulates at a circulation speed lower than the circulation speed commensurate with the amount of resin material supplied, the resin material cannot be completely filled into the cavity space and the mold block opens.
The load on the driving force for circulating the mold blocks increases rapidly, causing problems such as failure of the drive section of the pipe manufacturing apparatus.

The present invention has been made in view of the above-mentioned circumstances, and an object of the present invention is to provide a method of controlling a pipe-making apparatus that can prevent product defects and failures of the pipe-making apparatus.

[0008]

[Means for Solving the Problems] In order to solve the above problems, a method of controlling a pipe manufacturing apparatus according to the present invention surrounds a mandrel with a plurality of mold blocks connected in a belt shape, and connects the mold blocks and the mandrel. In a synthetic resin pipe manufacturing device that extrudes a resin material into a cavity space formed between
The clamping pressure of the mold block, which changes with changes in the supply pressure of the resin material, is detected over time, and the circulation speed of the mold block is controlled based on the detected pressure.

[0009] Furthermore, in the method for controlling a pipe manufacturing apparatus of the present invention, a mandrel is surrounded by a plurality of mold blocks connected in a belt shape, and a resin is injected into a cavity space formed between the mold block and the mandrel. In synthetic resin pipe manufacturing equipment that extrudes material and sequentially delivers and circulates mold blocks to form pipe bodies, the gap between the mold blocks changes over time as the supply pressure of the resin material changes. The mold block circulation speed is controlled based on the detected gap.

0010

[Operation] A mandrel is surrounded by a plurality of mold blocks connected in a belt shape, and the resin material is extruded into the cavity space formed between the mold blocks and the mandrel, and the mold blocks are sequentially sent out to form a tube. to form. At this time, the clamping pressure of the mold block, which changes with changes in the supply pressure of the resin material, is detected over time, and the circulation speed of the mold block is controlled based on this detected pressure, so that the resin material is constantly The cavity space is filled with a constant supply pressure. Furthermore, since the resin material is always filled into the cavity space at a constant supply pressure, it is possible to prevent a sudden increase in the load on the driving part that circulates the mold blocks.

[0011] Furthermore, by detecting the gap between the mold blocks that changes over time as the supply pressure of the resin material changes, and controlling the circulation speed of the mold blocks based on the detected gap, the resin material is The cavity space is always filled with a constant supply pressure. Furthermore, since the resin material is always filled into the cavity space at a constant supply pressure, it is possible to prevent a sudden increase in the load on the driving part that circulates the mold blocks.

0012

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

[0013]

Embodiment 1 An embodiment of the invention as claimed in claim 1 is shown in FIGS. 1 to 3. 1 and 2 show the main parts of a tube manufacturing device 1 for manufacturing a ribbed tube 2, and FIG. 3 shows a manufacturing line using the same tube manufacturing device 1. As shown in FIG.

That is, the pipe manufacturing apparatus 1 for making the ribbed pipe 2 includes a mandrel 12 surrounded by a plurality of mold blocks 11 connected like a belt, and a pipe formed between the mold blocks 11 and the mandrel 12. The ribbed tube 2 is molded by extruding the resin material 4 into the cavity space 3, and by sequentially feeding out and circulating the mold blocks 11. The pressure sensor 5 detects the clamping pressure of the mold block 11 over time, which changes with the change in the supply pressure of the resin material 4, and controls the circulation speed of the mold block 11 based on the detected pressure. It is.

The mold block 11 includes a tube body molding section 131 for molding a portion corresponding to the tube body 21 of the ribbed tube 2, and a rib for molding a portion corresponding to the rib 22 of the ribbed tube 2. A molded portion 132 is formed.

[0016] The mold block 11 thus constructed is as follows:
A plurality of molds are connected in a belt shape, and two split mold groups 14, 1
A pipe manufacturing apparatus 1 is configured to include a pipe manufacturing apparatus 5. That is, the split mold groups 14 and 15 include a plurality of mold blocks 11 with their respective mold surfaces 13 facing outward, and a first slide substrate 16 and a second slide substrate 17.
Attached to the outer circumferential surface of the Then, a part of the straight line area 14a
A first split mold group 14 connected in an annular manner and a second split mold group 15 having the same configuration as the first split mold group 14 are constructed.

These first and second split mold groups 14, 15
In this case, the respective mold blocks 11 and 11 are disposed directly facing each other in the linear regions 14a and 15a, and the second split mold group 1 is arranged opposite to the first split mold group 14.
5 is biased in the mold clamping direction.

That is, the first slide substrate 16 of the first split mold group 14 is attached to the support member 1 erected from the apparatus main body 10.
80, it is fixed in a predetermined position in advance. This first slide board 16 has a tightening bolt 19.
An insertion hole 161 is provided. In addition, the support member 18
0, a guide bar 18 is provided upright.

On the other hand, the second sliding base plate 17 of the second split mold group 15 is provided with a guide hole 171 through which the guide bar 18 can be inserted, and a tightening bolt 19 is screwed therein.

The guide hole 171 of the second slide board 17 is inserted into the guide bar 18, and the second slide board 17 is movable along the guide bar 18 in the mold clamping direction or in the mold clamping direction. There is. Further, the tightening bolt 19 screwed onto the second slide board 17 is inserted into the insertion hole 161 of the first slide board 16, and a nut 192 is screwed onto the insertion end side of the bolt 19 via a disc spring washer 191. . That is, by adjusting the degree of threading between this nut 191 and the second slide board 17, the degree of clamping of the second split mold group 15 with respect to the first split mold group 14 is determined. The degree of threading is adjusted by rotating the tightening bolt 19 using a motor (not shown) or the like.

However, when the second slide substrate 17 is urged against the first slide substrate 16 in this manner, the mold block 11 bears all of the urging force, resulting in deformation of the mold block 11 and an increase in driving load. This may cause other inconveniences. Therefore, a spacer 181 is provided on the guide bar 18 to reduce the urging force applied to the mold block 11.

In the pipe-making apparatus 1 constructed as described above, the first split mold group 14 and the second split mold group 15 move in opposite directions at a predetermined speed, that is, in FIG. 1, the first split mold group 14 The second split mold group 15 circulates in the clockwise direction, and the second mold group 15 circulates in the counterclockwise direction, whereby each mold block 11, 11 of each group 14, 15 creates a cavity space 3 between it and the mandrel 12. It is configured to move horizontally in the same direction (rightward in the figure) in the formed state.

The pressure sensor 5 is provided at a portion that receives the biasing force between the second slide substrate 17 and the first slide substrate 16. If the difference α obtained by subtracting the mold clamping pressure during idle operation from the mold clamping pressure during molding deviates from a predetermined value, the circulation speed of the mold block 11 is controlled. The specific mounting position of this pressure sensor 5 is as follows:
between the disc spring washer 191 and the nut 192, between the disc spring washer 191 and the first slide board 16, etc.
It is installed at a position where the measured value of the pressure sensor 5 increases when the supply pressure of the resin material 4 increases, that is, at a position where the mold clamping pressure can be directly measured. Further, the pressure sensor 5 may be built into the spacer 181 provided on the guide bar 18. In this case, when the supply pressure of the resin material 4 increases, the measured value of the pressure sensor 5 will decrease, so it is possible to indirectly measure the mold clamping pressure from this measured value. Furthermore, it is also possible to provide a tensile force sensor (not shown) on the tightening bolt 19 and measure the mold clamping pressure from this tensile force.

Note that the number of pressure sensors 5 to be provided is as follows:
If each slide bar 18 and tightening bolt 19 are provided at the above-mentioned locations, pressure changes can be measured with the highest accuracy.
There is no particular limitation as long as the change in the biasing force between 7 and the first slide substrate 16 can be measured.

Next, the ribbed tube 2 is made by this tube manufacturing device 1.
A method of controlling the circulation speed of the mold block 11 when manufacturing the mold block 11 will be explained.

First, the first and second split mold groups 14 and 15
is circulated at a constant speed as described above, and the molten resin material 4 extruded from the extruder 7 through the extrusion mold 6 is fed into the cavity space 3 formed between the mold block 11 and the mandrel 12.

At this time, for example, the pressure sensor 5
Assuming that the mold clamping force applied to is 2000 kgf, during molding, an urging force acts in the opposite mold clamping direction due to resin pressure, etc., so the mold clamping force applied to the pressure sensor 5 is normally 2100 kgf, and the difference α is 100 kgf.

Therefore, if this difference α exceeds 150 kgf, the circulation speed of the mold block 11 is increased by 1%. If the weight exceeds 200kgf, mold block 1
Increases the circulation speed of 1 by 2%. And with this,
A sudden increase in the supply pressure of the resin material 4 to the cavity space 3 is prevented, and at the same time, an increase in load on the driving portion is also prevented.

Furthermore, if the difference α is less than 50 kgf, the circulation speed of the mold block 11 is reduced by 0.5%. In the case of 0 kgf, the circulation speed of the mold block 11 is reduced by 1%. This prevents insufficient filling of the resin material 4 into the cavity space 3.

[0030] Even if this difference α changes slightly (±20 kgf) from the predetermined value of 100 kgf, the circulation speed is slightly controlled by about 0.1 to 0.2% depending on the amount of change. It is preferable. However, once the circulation speed is changed, the mold block 11 is 0.6 to 1
The next speed control is not performed until the robot has moved m.

Thereafter, the ribbed tube 2 manufactured by this pipe manufacturing apparatus 1 is passed through a cooler 8 located downstream of the pipe manufacturing apparatus 1.
cooled by

After cooling, the ribbed tube 2 is cut into a suitable length at approximately the center of the tube body 21 by a cutting device (not shown).

[0033]

[Embodiment 2] An embodiment of the invention as claimed in claim 2 is shown in FIGS. 4 and 5. This example differs only in that a displacement gauge 9 is used instead of the pressure sensor 5 of the first embodiment, so only the difference will be explained here, and other explanations will be omitted. Note that the same components as in the first embodiment are given the same reference numerals.

That is, in this embodiment, the displacement meter 9 detects the gap between the mold blocks 11 which changes with the change in the supply pressure of the resin material 4 over time, and the gap between the mold blocks 11 is detected based on the detected pressure. It controls the circulation speed of

The displacement meter 9 is provided between the first slide substrate 16 or the device main body 10 and the second slide substrate 17 or a portion that moves together with the second slide substrate 17. The circulation speed of the mold block 11 is controlled when the mold block 11 moves beyond a predetermined range from the mold clamping position during molding. As this displacement meter 9, an electric dial gauge, a differential transformer, or the like is used. Further, the specific mounting position of this displacement meter 9 is between the device main body 10 and the nut 192 at the lower end of the tightening bolt 19, as shown in FIG. 4, or between the tightening bolt 19, as shown in FIG. When the supply pressure of the resin material 4 increases, such as between the screwed nut 193 and the first slide board 16, the molds of the first split mold group 14 and the second split mold group 15 It can be mounted in a position where the degree of opening can be measured.

It should be noted that the number of displacement meters 9 to be provided is such that changes in the degree of opening of the mold can be measured most accurately if they are installed at the above-mentioned locations near each slide bar 18 and tightening bolt 19; There is no particular limitation as long as the degree of opening of the first split mold group 14 and the second split mold group 15 can be measured.

Normally, when the distance between the first slide substrate 16 and the second slide substrate 17 is measured using the displacement meter 9, it is approximately 0.01 to 0.05 mm. Therefore, when this interval exceeds 0.05 mm, the circulation speed of the mold block 11 is increased. This prevents a sudden increase in the supply pressure of the resin material 4 to the cavity space 3, and at the same time prevents an increase in the load on the driving portion. Moreover, when this interval is less than 0.01 mm, the circulation speed of the mold block 11 is reduced. This prevents insufficient filling of the resin material 4 into the cavity space 3.

[0038]

[Effects of the Invention] As described above, according to the present invention, the resin material is always filled into the cavity space at a constant supply pressure, so that the shape of the product changes due to insufficient filling, or burrs occur due to overfilling. It is possible to prevent the occurrence of defective products due to such reasons. Further, since the load on the drive portion that circulates the mold blocks is prevented from increasing rapidly, the drive force is stabilized and failures of the pipe manufacturing apparatus are prevented.

[Brief explanation of drawings]

FIG. 1 is a partially cutaway side view schematically showing the main parts of a pipe manufacturing apparatus according to a first embodiment.

FIG. 2 is a sectional view taken along the line AA in FIG. 1;

FIG. 3 is a schematic diagram showing a manufacturing line using a pipe manufacturing device.

FIG. 4 is a partially cutaway side view showing the main parts of the pipe manufacturing apparatus according to the second embodiment.

FIG. 5 is a partially cutaway side view showing another embodiment of the main part of the pipe manufacturing apparatus according to the second embodiment.

[Explanation of symbols]

1 Pipe manufacturing equipment 11 Mold block 12 Mandrel 2 Ribbed tube (pipe body) 3 Cavity space 4 Resin material

Claims (2)

[Claims] Claim 1: A mandrel is surrounded by a plurality of mold blocks connected in a belt shape, and a resin material is extruded into a cavity space formed between the mold blocks and the mandrel, and the mold blocks are sequentially delivered and circulated. In a pipe manufacturing device for synthetic resin pipes, which is designed to mold pipe bodies by applying pressure to the mold block, the clamping pressure of the mold block, which changes with changes in the supply pressure of the resin material, is detected over time, and the pressure is adjusted to the detected pressure. 1. A method for controlling a pipe manufacturing device, comprising controlling the circulation speed of a mold block based on the following. 2. A mandrel is surrounded by a plurality of mold blocks connected in a belt shape, and the resin material is extruded into a cavity space formed between the mold blocks and the mandrel, and the mold blocks are sequentially fed out and circulated. In a synthetic resin pipe manufacturing device that molds a pipe body by molding the resin material, the gap between the mold blocks that changes with changes in the supply pressure of the resin material is detected over time, and based on this detected gap, the 1. A method of controlling a pipe manufacturing device, comprising: controlling the circulation speed of a mold block.