JPH0723486B2 - Manufacturing method of multi-axis compound cylinder - Google Patents

Description

Description: FIELD OF THE INVENTION The present invention relates to the provision of an improved manufacturing means for obtaining a multi-axial composite cylinder used for the kneading of plastic materials and food materials.

(Prior Art) When kneading a plastic material or a food material, a screw or a rotor is rotatably mounted in a cylinder, a plurality of materials are charged into the cylinder, and the screw or rotor is rotated to The kneading and transferring are performed. In this case, the inner diameter surface shape of the cylinder is generally two holes in which two screws or rotors are arranged side by side so that two holes communicate with each other in the axial direction. It has an open cross-sectional shape, and the same inner diameter surface is corroded by wear caused by friction when the material flows and by substances generated by thermal decomposition of various organic substances added together with the material. For this reason, an alloy powder having corrosion resistance and wear resistance is applied as a surface guard to the inner diameter surface of the cylinder, and in this respect, the following prior art exists. That is,
As disclosed in No. 60-181208, the inner wall surface of a screw hole formed in a cylinder body made of an integral steel material is filled with wear-resistant or corrosion-resistant alloy powder, and a hot isostatic press (HIP press) is used. It is formed and sintered and adhered by a known means), and in the same publication, as a prior art before that, for example, a bimetal liner divided into two is integrally welded to the inner diameter surface. That the same liner and cylinder are split into two and welded together, or that a core is put in the cylinder inner diameter surface and molten alloy is poured and adhered is also disclosed. Is the street.

(Problems to be Solved by the Invention) Means for filling the inner wall surface of the screw hole formed in the cylinder body with wear-resistant and corrosion-resistant alloy powder and integrally sintering and depositing the powder by HIP pressing means , There are problems in the following points. That is, in the same means, hollow cores are inserted concentrically into a pair of screw holes having parallel and communicating portions in the cylinder body, and the target alloy powder is filled in the space between the screw holes and the core. Then, the powder is sintered and adhered to the inner surface of the screw hole by the HIP pressing means, but after the HIP treatment, the hollow core and the wall portion made of the alloy powder which is sintered and integrated between the cores,
It is indispensable to have a means for processing and forming two consecutive screw hole inner diameter surfaces by cutting and removing them so that they have a predetermined shape and dimension. The cross-sectional shape of the surface has the disadvantage of being restricted by the shape category that can be machined called cutting, and the alloy part formed in the wall shape between the core and the cores aligned with each other is
Since all of them are cut and removed, loss of material will occur. In addition, the restriction of the cross-sectional shape of the inner diameter surface to the range of shapes that can be machined, such as cutting, results in that the required shape of the inner diameter surface of the cylinder hole, which is necessary for improving the extrusion and kneading functions, cannot be obtained. It will also be done.

(Means for Solving the Problems) In order to solve the above-mentioned problems in the integral sintering deposition means using such cores and HIP treatment of metal powder, the present invention uses HIP for the metal powder for the inner diameter surface guard. By applying it integrally on the inner diameter surface by processing, accurately controlling the inner diameter surface shape by the core, and making it possible to post-draw or extrude the core, there is no need for cutting removal processing. A cylinder inner diameter surface having a desired cross-sectional shape and dimensions can be easily obtained.

That is, according to the present invention, a lining layer is formed by hot isostatically pressurizing the metal powder for guarding the inner diameter surface on the inner diameter surface of the cylinder formed by at least two or more holes in the cylinder having a communicating portion in the axial direction. In the method for manufacturing a multi-axis composite cylinder, the cylinder is made of a metal material having a cross-sectional shape equivalent to the inner diameter surface of the cylinder and having a thermal expansion coefficient larger than that of the cylinder-constituting metal material, and at the time of hot isostatic pressing. In, insert a core having a property of preventing diffusion bonding with the metal powder, and fill the space formed between the outer peripheral surface of the core and the cylinder inner diameter surface with the metal powder to heat the metal powder. It is characterized in that it is sintered on the inner diameter surface of the cylinder by isostatic pressing and then the cylinder and the core are both allowed to cool and then the core is extracted from the cylinder. .

Specifically, by coating the outer peripheral surface of the core with a release agent, the core is given the property of preventing diffusion bonding with the metal powder.

The release agent is an inorganic release agent and has an inorganic particle size of
It is preferably 150 μm or less.

(Operation) In the present invention, the core is made of a metal material having a larger thermal expansion coefficient than the metal material of the cylinder, and has the property of preventing diffusion bonding with the metal powder during hot isostatic pressing. If both the cylinder and the core are allowed to cool in the cooling process after applying the isotropic pressure, the core contracts more than the cylinder, and the contraction causes a gap between the core and the lining layer made of metal powder. .

(Example) Hereinafter, the Example of this invention is described in full detail based on drawing.

As illustrated in each of FIGS. 1, 2 and 3, the two screws or rotors in the cylinder 3 shown in FIG. 2 are installed side by side in parallel with each other in the axial direction and the axial direction thereof. In the cylinder inner diameter surface 3a composed of two holes 5a, 5a which are communicated with each other by the communication portion 5b,
A solid single core 2 including columnar portions 2a and 2a corresponding to a and 5a and a wall portion 2b corresponding to the communicating portion 5b is attached to a cylinder inner diameter surface 3a.
Since the space 4 for filling the metal powder for the guard is concentrically inserted between and, the material of the core 2 is made of a metal material having a larger coefficient of thermal expansion than the material of the cylinder 3. Further, as shown in FIG. 1, the release agent 1 made of an inorganic material is integrally coated on the entire outer peripheral surface of the core 2 with a required film thickness. After that, the space 4
A guard metal powder (not shown) with wear resistance, corrosion resistance, etc. is filled inside and sealed in a known hot isotropic pressure pressurizer, and the guard metal powder is integrally attached to the cylinder inner diameter surface 3a. Let them do it. After the HIP process, if the cylinder 3 is taken out of the apparatus and allowed to cool to room temperature, a difference in thermal expansion between the core 2 and the cylinder 3 causes a gap between the inner diameter surface 3a of the cylinder 3 and the core 2, and Coupled with the fact that the outer peripheral surface of the core 2 is coated with the release agent 1, the core 2 can be easily pulled out or extruded by cutting the sealed portions at both axial ends of the cylinder 3. As shown in FIG. 3, the cylinder inner diameter surface 3a is obtained.
Lining layer 6 made of a metallic material for guard over the entire surface of the
It is possible to obtain a cylinder 3 in which the cylinder is integrated, and it is not necessary to use the conventional cutting process, and the cylinder inner surface 3a and the core 2
Cylinders 3 having a desired inner diameter and inner diameter 3a (including the lining layer 6) have the same cross-sectional shape and dimensions as the non-cut body. Accurate and easy to obtain,
As a post-treatment for finishing the inner diameter surface, a slight degree of polishing (polishing) of the lining layer 6 is sufficient, and even with the cylinder inner diameter surface 3a having an unsteady cross-sectional shape, it is possible to provide the cylinder 3 realized with high accuracy. It becomes.

In FIG. 2, the cylinder 3 is made of a steel material such as SCM440, and in the embodiment, a hole 5a into which an adjacent screw or rotor is inserted is formed by a communicating portion 5b which is parallel to the pair in the axial direction and is parallel to the axial direction. 5a is drilled. On the other hand, the single core 2 used in the present invention has a coefficient of thermal expansion of at least that of the cylinder 3 as a material.
By using a metal material having a size of 4 × 10 ⁻⁶ cm / ° C. or more, such as austenitic stainless steel material, the inner diameter surface 3a of the cylinder 3 including the holes 5a, 5a of the cylinder 3 at room temperature (room temperature) and the core 2 are A gap is created at the boundary. The cross-sectional shape of the single core 2 is the cylinder inner diameter surface 3a.
A pair of columnar portions 2a, 2a having the same shape as the cross-sectional shape in which the pair of holes 5a, 5a are connected, and both columnar portions 2a, 2a across the communicating portion 5b.
It is a solid body integrally formed with a wall-shaped portion 2b that connects the two, and is dimensionally provided between the entire peripheral surface of the core 2 and the cylinder inner diameter surface 3a for powder filling in a substantially spectacle shape. A space 4 shall be formed. By using the single core 2 as described above, it is extremely easy to set and insert the multi-axis cylinder, and the shape of the communicating portion 5b can be accurately regulated by the presence of the wall-shaped portion 2b, and the cylinder inner diameter surface It is easy to uniformly define the surface of the guard metal layer along 3a.

Further, the core 2 has a property of preventing diffusion bonding with the metal powder during hot isostatic pressing. Specifically, this property is provided on the outer peripheral surface of the core 2 by a release agent. Are applied by coating. This is because both the cylinder 3 and the core 2 are metallic materials, and metal powder is used for the guard, so that diffusion bonding can be avoided by the subsequent HIP treatment and the core 2 can be easily separated. Therefore, the material of this mold release agent 1 is 10
An aqueous one-component paste made of 0% inorganic material is used. This is to prevent adverse effects on heat, for example, using a paste containing a mixture of zirconia + pure water + inorganic binder, spray-coating the entire outer peripheral surface of the core 2 to a thickness of about 0.3 t, and hardening at room temperature (15 ° C). After checking that the pencil hardness is 4H or more, the single core 2 is concentrically mounted inside the cylinder inner diameter surface 3a. The HIP process is the same as the conventional method, in which both ends of the cylinder 3 in the axial direction are sealed and the whole is sealed in a HIP device, for example, 1150.
By applying isotropic pressure at a heating temperature of ℃ and a pressure condition of 1000 kg / cm ² × 4 Hr, for example, Co-based wear-resistant and corrosion-resistant alloy powder filled in the section 4 is integrated on the cylinder inner diameter surface 3a side. Then, the lining layer 6 is formed. HIP
After the treatment, the sealed both ends of the cylinder 3 which has been taken out and allowed to cool can be cut, and the single core 2 can be extruded and easily released from the mold.

The dimension of the inner diameter surface 3a is the diameter of the core 2 before HIP treatment (HIP
The diameter before and after the treatment remained unchanged), and a result of 50 to 100 μ / φ65 could be obtained. At this time, the surface roughness of the inner diameter surface 3a is in the range of Rmax6 to 8 with the release agent 1 still attached,
By simple surface polishing, it is possible to obtain a surface roughness specification value of the normally used cylinder inner diameter surface of about 2 to 3 seconds. In the release agent 1, when using an aqueous one-component paste made of an inorganic substance, the particle size of the inorganic substance is 15 in order to maintain the boundary surface roughness after the HIP treatment.
It is desirable that the thickness be 0 μ or less. The above-mentioned example is limited to one example, and the coating film thickness of the release agent 1 is appropriately set in the range of 0.05 to 0.4 mm, but other than the above-mentioned conditions, appropriate changes can be made.

(Effect of the Invention) According to the method of the present invention, when both the cylinder and the core are allowed to cool after hot isostatic pressing, the core contracts more than the cylinder, and the contraction results in the core and the metal powder. Since a gap is created between the lining layer and the core, the core can be pulled out from the cylinder without any cutting.Therefore, when manufacturing a multi-axis composite cylinder having a lining layer on the inner surface, the manufacturing cost and manufacturing time are reduced. It can be significantly reduced.

[Brief description of drawings]

FIG. 1 is a perspective view of an embodiment of a core used in the method of the present invention, FIG. 2 is a front view in the axial direction showing a set state of a cylinder and a core in the method of the present invention, and FIG. FIG. 1 ... Release agent, 2 ... Single core, 3 ... Cylinder, 3a ...
… Cylinder inner diameter surface, 4 …… Space for filling metal powder, 5a ……
Hole, 5b ... communication part, 6 ... lining layer.

Claims (3)

[Claims] 1. A lining layer is formed by hot isostatic pressing of a metal powder for guarding an inner diameter surface on the inner diameter surface of a cylinder formed of at least two or more holes in the cylinder having a communicating portion in the axial direction. In the method for producing a multi-axis composite cylinder, a metal material having the same cross-sectional shape as the inner diameter surface of the cylinder and a coefficient of thermal expansion larger than that of the cylinder-constituting metal material and at the time of hot isostatic pressing Insert a core having the property of preventing diffusion bonding with the metal powder, fill the space formed between the outer peripheral surface of the core and the cylinder inner diameter surface with the metal powder, and heat the metal powder A multi-axis compound which is characterized in that it is sintered on the inner diameter surface of the cylinder by isotropic pressure pressurization, and then the cylinder and the core are both allowed to cool and then the core is extracted from the cylinder. Process for the preparation of the cylinder. 2. The core according to claim 1, wherein the outer peripheral surface of the core is coated with a release material so that the core has a property of preventing diffusion bonding with metal powder. Manufacturing method of multi-axis compound cylinder. 3. The release agent is an inorganic release agent, and the inorganic particle size is
Claim 2 characterized in that it is 150μ or less
A method for manufacturing a multi-axis composite cylinder according to the item.