JPH03143609A - Mandrel for manufacturing of rubber hose, extruding device for which the same mandrel is used and manufacture of rubber hose with the same device - Google Patents

Abstract

PURPOSE:To enable always extrusion molding in uniform thickness, by a method wherein a mandrel having magnetism on the surface is used, an extruding machine is provided with a moving device moving an outer die, and a thickness measuring device is arranged in front of the extruding machine. CONSTITUTION:A long-sized mandrel 61 having magnetism on the surface is inserted through an insertion hole 29 for the mandrel of an inner die holder 31, the tip part is projected through an extrusion port 41, then extruded from the extrusion port 41 by passing through a material feed port 25 and extrusion passage 39 with a screw 23 and a rubber layer is molded. An extrusion-molded rubber layer is moved forward and passes through the inside of a thickness measuring device 55. In this instance, since the surface of the long-sized mandrel 61 possesses the magnetism, a thickness is measured by a sensor part 60. A measured result is operated by the central treatment device and in the case where the same is different from a predetermined fixed thickness value, a control device of a hydraulic cylinder 45 is controlled by sending out a signal to the hydraulic cylinder 45 so that the thickness becomes uniform.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a mandrel for manufacturing a rubber hose, an extrusion device using the mandrel, and a method for manufacturing a rubber hose using the device.

(Prior art) Conventionally, the manufacturing method for reinforced rubber hoses involves preparing a long mandrel of rubber or resin with a reinforcing core, extruding an inner rubber layer around the outer periphery of this long mandrel, and then forming an inner rubber hose. After applying a reinforcing layer to the outer periphery of the layer, extrusion molding is performed on the outer periphery of the reinforcing layer.This rubber layer is vulcanized together with a long mandrel, and after vulcanization, the mandrel is extracted from a long rubber hose using water pressure and the long rubber hose is extruded. The rubber hose is then cut to a predetermined length and used.

A method of extrusion molding an inner rubber layer using a conventional extruder will be explained based on FIG.

A conventional extruder is constructed as follows.

That is, the extruder main body 1 includes a screw 3 for transporting the rubber.
It has a material supply port 5 for supplying the transferred rubber, and a block 10 is disposed inside, and an inner die holder 9 having a mandrel insertion hole 7 is fixed to this block 10. The block 10 is provided with an extrusion passage 12 consisting of an annular gap, and an inner die 11 is fixed to the tip of the inner die holder 9.

Further, an outer die 1 is provided outside the inner die 11.
3 is screwed and fixed to the outer die holder 15. The outer die holder 15 is supported by thickness unevenness adjustment bolts 17 provided in the vertical and horizontal directions of the main body 1. Therefore, the annular gap between the inner die 11 and the outer die 13 becomes an extrusion passage 14 communicating with the extrusion passage 12,
The outlet becomes the extrusion port 16, and the uneven thickness adjusting bolt 1
By adjusting the protrusion amount of 7, the outer die holder 15, that is, the outer die 13 can be moved up and down, right and left, and diagonally.

Since the conventional extrusion device is configured as described above, in order to extrude the inner rubber layer 19, the prepared long mandrel 18 is inserted into the mandrel insertion hole 7 of the inner die holder 9, and the material is removed by the screw 3. The rubber supplied to the supply port 5 is extruded from the extrusion port 16 to coat the outer periphery of the long mandrel 18. After applying the reinforcing layer, the outer rubber layer may be extruded in the same manner as the inner rubber layer.

(Problem M to be Solved by the Invention) However, the conventional method for manufacturing a reinforced rubber hose has the following problems.

That is, the inner rubber layer and the outer rubber layer are extruded from the extrusion port 16 between the inner die 11 and the outer die 13, and their thicknesses must be uniform. Adjustment of the wall thickness is carried out by adjusting the amount of protrusion of the flesh adjustment bolt 17 and moving the outer die 13 vertically, horizontally, or diagonally during extrusion molding. However, such adjustment of uneven thickness is performed based on the intuition of the operator based on many years of experience, and is an operation that requires skill. Further, since the thickness unevenness adjustment is performed by loosening one thickness unevenness adjustment bolt 17 and tightening the opposite side thickness unevenness adjustment bolt 17, there is a problem of poor workability.

Furthermore, even if the wall thickness is set uniformly, uneven thickness may occur during extrusion molding, so there is a problem in that regular inspections and adjustments must be repeated. Especially when manufacturing rubber hoses using long mandrels,
Inspecting and adjusting uneven thickness was a major obstacle.

(Means for Solving the Problems) Therefore, it is an object of the present invention to provide a mandrel for manufacturing a rubber hose that solves the above problems, an extrusion device using the mandrel, and a method for manufacturing a rubber hose using the device. This invention has the following configuration.

That is, in the extrusion apparatus of the present invention, there is provided a moving device for moving the outer die of the extruder, and a sensor section disposed in front of the extruder, consisting of a proximity sensor and a displacement sensor, arranged at least on the top, bottom, left and right sides. It consists of a measuring device and a central processing unit (CPU) that calculates the measurement results from the wall thickness measuring device and operates and controls the moving device, and is characterized by using a mandrel having a magnetic surface.

A mandrel having a magnetic surface may be formed by coating the surface of the main body with a magnetic layer, or the main body itself may be magnetic.

In the method for manufacturing a rubber hose using the extrusion device, a mandrel having a magnetic surface is used, an inner rubber layer is extruded around the outer periphery of the mandrel, and a wall thickness measuring device disposed in front is measured to determine the thickness of the inner rubber layer. The measurement result is calculated by the central processing unit (CPU), and if the thickness is uneven, the outer die moving device of the extruder is operated according to a command from the central processing unit (CPU) to make it uniform. This is a manufacturing method that makes the wall thick.

(Function) Since the mandrel surface is magnetic, the distance to the mandrel surface can be measured using a proximity sensor, while the distance to the rubber layer surface can be measured using a displacement sensor, making it possible to measure multiple locations. This makes it possible to measure uneven thickness.

In addition, the outer die moving device is a central processing unit (CPU)
The outer die can be moved according to commands from the controller to uniformly adjust the thickness of the extruded rubber layer.

(Example) The present invention will be described below based on the example shown in FIGS. 1 to 4.

Fig. 1 is a cross-sectional view of the extrusion device, Fig. 2 is a front view of a wall thickness measuring section, Fig. 3 is a front view of the extruder, and Fig. 4 is an explanatory cross-sectional perspective view showing an example of a long mandrel. .

The configuration of the extruder main body 21 is basically the same as that of a conventional extruder. That is, the main body 21 has a screw 23 and a material supply port 25, and an inner die holder 31 having a mandrel insertion hole 29 is fixed to a block 27 disposed inside. An inner die 33 is threaded.

An outer die 35 is screwed and fixed to an outer die holder 37 on the outer surface of the inner die 33, and the annular gap between the inner die 33 and the outer die 35 forms the material supply port 2.
The extrusion passage 39 communicates with the extrusion port 5, and its exit is the extrusion port 4.
It becomes 1.

The outer die holder 37 is provided with a moving device 42 . The moving device 42 is composed of a hydraulic cylinder 45 and a linear encoder 53. A hydraulic cylinder 45, which is a means for moving the outer die holder 37, is connected via a linear bearing 43. This linear bearing 43 is fixed to the outer die holder 37.

The linear encoder 53 is arranged on the opposite side from the hydraulic cylinder 45.

The moving device 42 may be configured by the hydraulic cylinder 45 and the linear encoder 53, or may be configured by a combination of a ball screw and a servo motor.

The hydraulic cylinder 45 and the linear encoder 53 are disposed perpendicularly in the vertical and horizontal directions as shown in FIG. 3, and move the outer die 35 in a direction perpendicular to the axial direction of the extrusion port 41. The hydraulic cylinder 45 and the linear encoder 53 are a central processing unit (CPU) which will be described later.
is connected to.

In front of the extruder main body 21 is the central processing unit (CP).
A wall thickness measuring device 55 connected to U) is provided. The wall thickness measuring device 55 moves a sensor unit 60, which is a pair of a proximity sensor 57 that measures the distance to the mandrel surface and a displacement sensor 59 (for example, a laser displacement sensor) that measures the distance to the extruded rubber layer surface, up and down. It is configured by arranging them in the left, right and diagonal directions.

Next, the elongated mandrel 61 used in the present invention consists of a main body 63 made of rubber or resin, and a flexible magnetic layer 65 provided on the surface of the main body 63. The magnetic layer 65 can be formed, for example, by coating the surface of the main body 63 with rubber mixed with iron powder. Providing a magnetic layer on the surface allows the proximity sensor 57 to measure the wall thickness.

Note that the long mandrel 61 is not limited to the above embodiment as long as it has a magnetic structure on its surface. Therefore,
The mandrel body may be magnetic.

Next, a method for manufacturing a rubber hose using the extrusion device having the above configuration will be described.

First, the elongated mandrel 61 having a magnetic surface is inserted into the mandrel insertion hole 29 of the inner die holder 31 to make the tip protrude from the extrusion port 41, and then, as in the conventional case, the screw 23 is used to insert the elongated mandrel 61 into the material supply port 25 and the extrusion aisle 3
9 and extruded from the extrusion port 41 to form a rubber layer 67. The extruded rubber layer 67 advances forward and passes through the thickness measuring device 55 . At this time, since the surface of the long mandrel 61 has magnetism, the sensor section 60 measures the wall thickness. That is, the proximity sensor 57 measures the distance to the mandrel surface, while the displacement sensor 5 measures the distance to the mandrel surface.
Since the distance to the rubber layer 67 is measured by 9, the measurement results from both sensors are calculated by a central processing unit (CPU). If the result of the calculation is that one side is thinner and the other side is thicker than the predetermined wall thickness value,
A signal is sent from the central processing unit (CPU) to a control device (not shown) for the hydraulic cylinder 45 to operate the hydraulic cylinder 45 and control the wall thickness to be uniform.

The wall thickness in the vertical and horizontal directions can be adjusted by operating one of the hydraulic cylinders 45, but the wall thickness in the diagonal direction can be adjusted by simultaneously operating both hydraulic cylinders 45 and combining movements in the two directions. It can be carried out.

After the inner rubber layer is extruded, a reinforcing layer such as fiber is applied to the outer periphery of the inner rubber layer, and an outer rubber layer is extruded around the outer periphery of the reinforcing layer. Vulcanize using the following method.

After vulcanization, the mandrel is removed and cut into short rubber hoses of a predetermined length.

In the above embodiments, extrusion molding of the inner rubber layer was explained, but the present invention can also be applied to extrusion molding of the outer rubber layer. In this case, rubber glue is usually applied to the surface of the reinforcing layer in order to strengthen the adhesion between the reinforcing layer and the outer rubber layer, so it is sufficient to mix a magnetic substance into this rubber glue to make it magnetic. . If the surface of the reinforcing layer has magnetism, the sensor part 6
The wall thickness of the outer rubber layer can be measured by measuring the distance to the reinforcing layer surface and the distance to the outer rubber layer surface using f.
The hydraulic cylinder 45 may be operated according to a command from the CPU (CPU) to control the wall thickness to be uniform.

(Effect of the invention) In this invention, a mandrel having magnetic properties on the surface is used,
The extruder is equipped with a moving device that moves the outer die,
A wall thickness measuring device is installed at the front of the extruder, which allows extrusion molding with a uniform wall thickness at all times, and because it is automatically controlled, there is no need for manpower, improving productivity. Can be done.

Moreover, unlike the conventional method, there is no need to cut and measure the wall thickness during extrusion molding, and it is excellent in manufacturing long rubber hoses using a long mandrel.

[Brief explanation of the drawing]

FIG. 1 is a sectional view of the extrusion device, FIG. 2 is a front view of the wall thickness measuring section, FIG. 3 is a front view of the extruder, and FIG. 4 is an explanatory cross-sectional perspective view showing an example of a long mandrel. FIG. 5 is a sectional view of a conventional extruder. 21 is the extruder main body, 23 is a screw, 25 is a material supply port, 27 is a block, 29 is a mandrel insertion hole, 31 is an inner die holder, 33 is an inner die, 35 is an outer die, 37 is an outer die holder 39 is an extruder passage, 41 is an extrusion port, 43 is a linear bearing, 45 is a hydraulic cylinder, 47 is a fixed plate, 49 is a notch, 51 is an adjustment bearing, 53 is a linear encoder, 55 is a wall thickness measuring device, 57 is a proximity sensor, 59 is displacement sensor,
60 is a sensor section, 61 is a long mandrel, 63 is a main body,
65 is a magnetic layer.

Claims (3)

[Claims] (1) A mandrel for manufacturing rubber hoses characterized by having magnetism on the surface. (2) a moving device that moves the outer die of the extruder;
A wall thickness measuring device disposed in front of the extruder and having sensor units including proximity sensors and displacement sensors arranged at least on the top, bottom, left and right sides, and calculating the measurement results from the wall thickness measuring device to operate and control the moving device. An extrusion device comprising a central processing unit (CPU) and using a mandrel having a magnetic surface. (3) Using a mandrel with magnetic surface, extrude an inner rubber layer around the outer periphery of the mandrel, measure the thickness of the inner rubber layer with a thickness measuring device installed in front, and send the measurement results to a central processing unit. If the thickness is uneven, the outer die moving device of the extruder is operated according to a command from the central processing unit (CPU), making it possible to extrude with a uniform thickness. The method for manufacturing a rubber hose according to claim 2, characterized in that: