JPH039803B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a device for detecting the extrusion length of an extruded material extruded by an extruder.

[Conventional technology]

As shown in FIG. 3, the extruder includes a container 2 equipped with a die 1, a ram 3, a traveling cutting machine 4,
A billet 6 is placed inside the container 2.
Insert the billet 6 through dummy 7 with ram 3.
The extruded material 8 is sequentially extruded from the die 1 by pressing , and the extruded material 8 is gripped and pulled by the puller 5, and the extruded material 8 is cut at a predetermined position with the cutting blade 4a of the traveling cutter 4. There is.

In such an extruder, a billet 6 with a length of 40 to 80 cm and a diameter of about 15 to 20 cm is inserted into a container 2, and by the pressing force of the ram 3, one billet is produced in one operation. A long extruded material 8 of 70 m to 80 m is extruded.

After the first extrusion is completed, a new billet 6 is
is inserted into container 2 and the second extrusion is performed, but normally when the second extrusion is performed, the fourth
As shown in the figure, there is a part 6' of the billet remaining from the first extrusion and a new billet 6 inserted for the second time.
If air or the like is present at the seam 9, and extrusion is performed in this state, surface defects such as rough skin and white spots may occur when the seam 9 portion is extruded as the extruded material 8.

When these surface defects occur, the extruded material loses its value as a product and must be disposed of as a defective product, resulting in poor product yield.

Therefore, the long extruded material 8 is usually cut near the surface defect portion to improve the product yield.

In this way, in order to cut the long extruded material 8 at the surface defect portion, the extruded length of the extruded material is detected, the operation of the traveling cutter 4 is controlled based on the extruded length, and the cutting blade 4a is used to cut the long extruded material 8. I try to do that.

Then, to detect the extrusion length of the extrusion material 8,
For example, as shown in Japanese Utility Model Publication No. 59-17446, it is conceivable to detect the amount of ram movement and to detect the extrusion length based on the amount of ram movement.

[Problem that the invention seeks to solve]

However, the ram does not contribute to extrusion at all until the dummy comes into contact with the billet, and there is a gap between the container 2 and the billet 6 as shown in FIG. Even if it comes into contact with the ram, extrusion will not start until the gap is closed, so it simply detects the amount of ram movement.
Even if the extrusion length is detected based on the amount of movement of the ram, the extrusion length cannot be detected accurately.

Therefore, an object of the present invention is to provide an extrusion length detection device for an extruder that can accurately detect the extrusion length of an extruded material based on the amount of ram movement.

[Means and actions for solving problems]

A ram movement amount detector, an extruded material length calculation section that calculates the extruded material length by multiplying the ram movement amount and the extrusion ratio, and an extruded material length calculation section that calculates the extruded material length when the fluid pressure in the ram is higher than the set pressure. and a calculation start command transmitter that outputs a calculation start command to start calculating the length of the extruded material when the fluid pressure in the ram reaches a pressure corresponding to the extrusion start pressure.

〔Example〕

As shown in FIG. 1, the extruder includes a container 21 equipped with a die 20, a ram 23 equipped with a dummy 22, a traveling cutter 24, and a puller 25. When pressure fluid is supplied to the contraction chamber 28, the stem 27 expands and the dummy 22 is pushed into the container 21, and when pressure fluid is supplied to the contraction chamber 28, the stem 27 contracts and the dummy 22 is pushed into the container 21.
2 comes out of the container 21 and stops at the ram origin X, and a ram pressure sensor 29 is provided to measure the fluid pressure in the extension chamber 26. Note that the dummy 22 may be separated from the stem 27 and discharged and reused after one extrusion is completed.

The traveling cutting machine 24 includes a belt conveyor 30 and a cutting blade that moves in synchronization with the belt conveyor 30, for example, a rotating saw blade 31. The saw blade 31 rotates and moves back and forth toward the extruded material 32. do.

The puller 25 is reciprocated by a moving mechanism (not shown), for example, a linear motor, and is equipped with a photoelectric switch 33, and in the moving path of the photoelectric switch 33, a large number of reflecting portions 34 are arranged at regular intervals in the longitudinal direction. A reflector plate 35 is disposed so that the light emitted from the light emitter 33a of the photoelectric switch 33 is reflected by the reflector 34, received by the light receiver 33b, and a pulse signal corresponding to the amount of movement of the puller 25 is output. The amount of movement of the puller 25 can be detected by counting the pulse signals.

The ram 23 is provided with a ram movement amount detector 36, and this ram movement amount detector 36 is connected to an encoder 40 on a bracket 38 fixed to the ram tube 37.
A pinion 39 fixed to the rotating shaft is engaged with a rack rod 39a fixed to the stem 27, and the encoder 40 is rotated by the expansion and contraction of the stem 27.The output pulse of the encoder 40 changes the amount of ram movement, In other words, the amount of expansion and contraction of the stem 27 can be detected.

Fluid pressure from a fluid pressure source 41 is supplied to the extension chamber 26 and contraction chamber 28 of the ram 23 by an electromagnetic switching type three-position switching valve 42, and the belt conveyor 30 is driven by a running motor 43. The saw blade 31 is rotated by a rotation motor 44 and moved back and forth by a cylinder (not shown) or the like.

FIG. 2 is a control circuit diagram, and the calculation section 50 includes a ram speed calculation section 51, an extrusion ratio calculation section 52, an extrusion ratio data switching section 53, an extrusion material speed calculation section 54, and a D/A
Converter 55, extruded material length calculation unit 56, first, second
It includes comparison circuits 57, 58 and an output circuit 59, and outputs a drive signal to the drive device 60, and also controls the rotation of the travel motor 43 and rotation motor 44.

The ram speed calculating section 51 uses a counter 51a that counts pulses (0.1 mm/pulse) from the rotary encoder 40, and a reference pulse (0.1 sec/pulse) from the reference time generating section 61 and this count value to calculate the ram speed. The extrusion ratio calculation unit 52 includes a ram speed calculation circuit 51b that calculates the speed, a first counter 52a that counts the pulses, a second counter 52b that counts the pulses (10 mm/pulse) from the photoelectric switch 33, 1st, 2nd
An extrusion ratio calculation circuit 52c is provided for calculating the extrusion ratio from the count values of counters 52a and 52b.

In other words, the extrusion ratio is puller movement amount/ram movement amount, the ram movement amount is detected by the first counter 52a, the puller movement amount is detected by the second counter 52b, and the second The extrusion ratio is calculated by dividing the count value of the counter 52b.

The extrusion ratio data switching unit 53 selects and outputs either the extrusion ratio manually input from the extrusion ratio setting unit 62 such as a numeric keypad or the extrusion ratio calculated.

The extruded material speed calculation section 54 is a ram speed calculation section 5.
The extrusion speed of the extruded material is calculated by multiplying the ram speed from 1 by the extrusion ratio. In other words, the extrusion speed of the extruded material is determined by ram speed x extrusion ratio.

The extruded material length calculation section 56 includes a counter 56a that counts pulses from the rotary encoder 40, and an extruded material length calculation circuit 56b that calculates the extruded material length by multiplying the count value and the extrusion ratio.
(that is, the length of the extruded material is the amount of ram movement ×
(obtained from the extrusion ratio), and the calculation is started in response to a calculation start command from the extrusion material length calculation start command sending unit 63.

The extrusion material length calculation start command transmitter 63 outputs a calculation start signal when the ram pressure detected by the ram pressure sensor 29 exceeds the set pressure of the extrusion start pressure setting device 64.

The first comparison circuit 57 includes an extruded material length calculation section 56
The length of the extruded material is compared with the length of the extruded material set in the constant setting section 65, and a saw blade rotation command, travel start command, puller start command, etc. are outputted to the drive device 60 via the output circuit 59.

The second comparison circuit 58 inputs the rotation of the traveling motor 43 from the tachometer generator 66, and inputs the speed of the extruded material as an analog signal from the D/A converter 55, and compares the two to determine whether the extruded material is extruded at the commanded speed. It is determined whether the vehicle is present, and feedback is provided to the drive device 60.

Next, the operation will be explained.

The first billet B ₁ is inserted into the container 21 with the stem 27 of the ram 23 at the origin position, and the extrusion ratio setting section 62 sets the extrusion ratio determined from the diameter of the die 20 and the billet or the inner diameter of the container 21 using the extrusion ratio data switching section. 53, the start button is pressed, the three-position switching valve 42 is set to the extended position, and pressure fluid is supplied to the extension chamber 26 to extend the stem 27.

At the same time, a pulse is output from the encoder 40, so the extruded material speed is calculated by the extruded material speed calculation section 54 based on the set extrusion ratio and the ram speed calculated by the ram speed calculation section 51. Since the fluid pressure in the chamber 26 is low and the measured value of the ram pressure sensor 29 is below the set pressure, a calculation start command is not output, so the extruded material length calculation section 56 does not perform calculation.

Then, the stem 27 is extended and the dummy 22 comes into contact with the billet _B1 , and when the billet _B1 is pressed and brought into close contact with the inside of the container 21, extrusion is then started.

As a result, the fluid pressure in the elongation chamber 26 increases and the measured value of the ram pressure sensor 29 becomes equal to or higher than the set pressure, and a calculation start command is output. The length of the extruded material is calculated and output to the first comparison circuit 57.

Since this is the case, the length of the extruded material must be calculated after extrusion is started.

Thereafter, the extruded material is sequentially extruded and reaches the puller 25, where the extruded material is gripped and pulled to complete the first extrusion.

Completion of the first extrusion is sensed when the stem 27 of the ram 23 reaches the extension stroke end position Y, and the three-position switching valve 42 is thereby
is switched to the retracted position, the stem 27 is retracted, and the dummy 22 is taken out from the container 21 and set at the origin position X.

As the puller 25 is pulled, the photoelectric switch 33 also moves and outputs a pulse, so the extrusion ratio calculation section 52 in FIG. 2 calculates the extrusion ratio and sends it to the extrusion ratio data switching section 53.

Then, the second billet B ₂ is placed in container 2.
1 and extends the stem 27 in the same manner as described above to start extrusion.The extruded material length calculation section 56 in FIG. is calculated.

When the length of this extruded material becomes the first set length l ₁ preset by the constant setting section 65, that is, the extruded length at which the part where the joint of the billet becomes the extruded material reaches the traveling cutting machine 24, The comparison circuit 57 outputs a saw blade rotation command and a belt conveyor running start command, and the driving device 60 drives the running motor 43 and the rotation motor 44, and the speed of the belt conveyor 30 is the same as the extruded material speed. It is controlled so that

As a result, the saw blade 31 rotates and moves together with the belt conveyor 30 in synchronization with the extruded material.
After moving to a certain extent, the saw blade 31 moves forward, cuts the extruded material at the billet joint, and retreats.

When the length of the extruded material is further extruded and reaches the second set length l ₂ preset by the constant setting section 65, that is, the length of the extruded material that reaches the puller 25, the first
A puller jack signal and a movement signal are outputted from the comparator circuit 57, and the puller 25 grasps the end of the extruded material and performs a pulling operation.

At this time, the extrusion ratio is calculated by the extrusion ratio calculation section 52 in FIG. 2 using the pulse output from the photoelectric switch 33, and is used as the extrusion ratio for the next extrusion.

In this way, the extrusion ratio calculated based on the actual value of the previous extrusion is used for the next extrusion, so
Even if the shape of the extruded material changes slightly due to thermal deformation of the die 20 and the theoretical extrusion length differs from the actual extrusion length, the extruded material speed and extruded material length can be calculated and determined more accurately. This enables precise cutting of extruded materials at billet seams.

Note that a preset extrusion ratio may be used instead of calculating and determining the extrusion ratio.

〔Effect of the invention〕

Since the length of the extruded material is calculated and detected based on the amount of ram movement and the extrusion ratio from the time the ram 23 starts extruding the billet, the length of the extruded material can be accurately detected based on the amount of ram movement.

[Brief explanation of the drawing]

1 and 2 show embodiments of the present invention;
The figure is an explanatory diagram of the extruder, the second figure is a control circuit diagram, and the third figure is an explanatory diagram of the extruder.
The figure is an explanatory diagram of a conventional extruder, and FIGS. 4 and 5 are diagrams illustrating its malfunctions. 20 is a die, 21 is a container, 23 is a ram, 56 is an extruded material length calculation section, and 63 is a calculation start command transmission section.

Claims (1)

[Claims] 1. In an extruder configured to extrude a billet inserted into a container 21 equipped with a die 20 using a ram 23, a ram movement amount detector 36 detects the amount of movement of the ram 23, and a fluid pressure inside the ram 23 is provided. A calculation start command transmitter 63 that outputs a calculation start command when the pressure exceeds a set pressure, and an extruded material length that calculates the length of the extruded material by multiplying the ram movement amount and the extrusion ratio according to the calculation start command. An extruded material length detecting device for an extruder, characterized by comprising a calculating section 56.