KR102602591B1 - Surface treatment method for regenerating dqmage mold - Google Patents

Abstract

The present invention relates to a surface treatment method for regenerating a damaged mold by surface treating the damaged mold with shot peening and ion nitriding.
The surface treatment method for regenerating a damaged mold according to the present invention includes a pretreatment step of performing pretreatment on the damaged mold; A shot peening step of performing short peening on the pretreated damaged mold; It includes an ion nitriding step of ion nitriding the damaged mold that has been subjected to shot peening.
The surface treatment method for regenerating a damaged mold according to the present invention removes and regenerates damaged cracks, scratches, etc. by pre-treating, shot peening, and ion nitriding the damaged mold surface, increases the surface strength of the mold, and reduces fatigue strength. prevents and improves durability, wear resistance and corrosion resistance.

Description

Surface treatment method for regenerating dqmage mold}

The present invention relates to a surface treatment method for regenerating a damaged mold by surface treating the damaged mold with shot peening and ion nitriding.

Die casting molds, extrusion molds, etc. suffer from damage such as cracks, scratches, and corrosion due to harsh usage environments, shortening their lifespan and causing them to be discarded early.

Shot peening is a surface treatment method that regenerates damaged molds through surface treatment. Shot peening increases surface strength by spraying peening balls at high pressure onto the surface of a metal workpiece and causing them to collide, thereby imparting residual stress. Shot peening has a problem in that small cracks may occur in the grooves that are created when hitting a metal workpiece with a peening ball, and that the fatigue strength of the metal workpiece decreases due to these cracks.

Therefore, it is necessary to remove cracks that may occur at the border of grooves in metal workpieces through shot peening.

For reference, conventional technologies for surface treatment of metal workpieces include Registered Patent No. 10-1781816, “Composite surface treatment method for improving the lifespan of die casting molds and related parts,” and Patent No. 10-0465509, “Impeller type short with cooling device.” Peening equipment” etc. were launched.

The present invention was created in response to this need. The surface of the damaged mold is regenerated by shot peening treatment, residual stress is applied to the mold surface to increase surface strength, and then ion nitriding treatment is performed to create grooves and grooves caused by hitting the pinning ball. The purpose is to provide a surface treatment method for regenerating damaged molds by removing cracks that occur in the border area, increasing fatigue strength, and reinforcing durability, wear resistance, corrosion resistance, etc.

The surface treatment method for regenerating a damaged mold according to the present invention to achieve this purpose is

A pretreatment step of performing pretreatment on the damaged mold;

It includes a shot peening step of performing short peening on the pretreated damaged mold.

And an ion nitriding step of ion nitriding the damaged mold that has been subjected to the shot peening treatment,

The shot peening equipment that performs the shot peening step includes an impeller that sprays peening balls into the damaged mold at high pressure, a housing that houses the impeller, an inlet provided in the housing to supply peening balls to the impeller, and a damaged mold. It includes an outlet for spraying into,

The outlet is detachably fastened to the housing through a bolt member and a nut member having a loosening prevention structure,

A drawing hole, a receiving groove, and a tool groove are formed in the vertical direction of the bolt member,

A core member is inserted into the outlet hole, a lower end of the core member is hinged with locking pieces elastically supported to rotate upward, and a first spring is provided in the receiving groove to elastically support the head of the core member upward. Built-in,

A pressure plate elastically supported by a second spring is built into the fastening hole of the nut member,

When a tool is inserted into the tool groove of the bolt member, the head of the core member is lowered by being pressed by the tool, and the locking pieces are rotated upward so that the end is located inside the pin portion of the bolt,

When the bolt member is fastened to the nut member, the locking pieces are spread by the force to move the core member upward by the first spring and the force to push the pressure plate by the second spring, so that the ends are connected to the nut member. It is characterized by being forcefully coupled to the inner wall of the fastening hole.

And the damaged mold according to the present invention is characterized by surface treatment by the above surface treatment method.

The surface treatment method for regenerating a damaged mold according to the present invention removes and regenerates damaged cracks, scratches, etc. by pre-treating, shot peening, and ion nitriding the damaged mold surface, increases the surface strength of the mold, and reduces fatigue strength. It is a technology that prevents and improves durability, wear resistance, and corrosion resistance, and is a very useful invention for industrial development.

1 is a flowchart of a surface treatment method for regenerating a damaged mold according to the present invention.
Figure 2 is a view illustrating a bolt member and a nut member having a loosening prevention means in the shot peening equipment that performs the shot peening step according to the present invention.
Figure 3 is a photograph of heating equipment used in the pretreatment step.
Figure 4 is a photograph of shot peening equipment used in the shot peening step.
Figure 5 is a photograph of plasma equipment used in the ion nitriding step.
Figure 6 is a photograph of a mold processed in the preparation stage, pre-treatment stage, and shot peening stage.

Hereinafter, with reference to the drawings, the surface treatment method for regenerating a damaged mold according to the present invention and the sleeve surface treated accordingly will be described in more detail.

Before explaining in more detail the surface treatment method for regenerating a damaged mold according to the present invention and the sleeve surface treated accordingly,

Since the present invention can be subject to various changes and can have various forms, implementation examples (or embodiments) will be described in detail in the text. However, this is not intended to limit the present invention to a specific disclosed form, and should be understood to include all changes, equivalents, and substitutes included in the spirit and technical scope of the present invention.

In each drawing, the same reference signs, especially the tens and ones digits, or the same tens, one's, and alphabets, indicate members having the same or similar functions, and unless otherwise specified, each of the drawings The member indicated by the reference sign can be understood as a member that complies with these standards.

In addition, in each drawing, the components are expressed exaggeratedly large (or thick), small (or thin), or simplified in size or thickness in consideration of convenience of understanding, etc., but as a result, the scope of protection of the present invention is interpreted as limited. It shouldn't be.

The terms used in this specification are merely used to describe specific implementation examples (sun, aspect, aspect) (or examples), and are not intended to limit the present invention. Singular expressions include plural expressions unless the context clearly dictates otherwise. In this application, terms such as ~include~ or ~consist of~ are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but are not intended to indicate the presence of one or more other features. It should be understood that this does not exclude in advance the possibility of the existence or addition of elements, numbers, steps, operations, components, parts, or combinations thereof.

Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by a person of ordinary skill in the technical field to which the present invention pertains. Terms defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the related technology, and unless explicitly defined in the present application, should not be interpreted in an ideal or excessively formal sense. No.

As shown in the drawing, the surface treatment method for regenerating a damaged mold according to the present invention consists of a damaged mold preparation step (S10), a pretreatment step (S20), a shot peening step (S30), and an ion nitriding step (S40).

In the damaged mold preparation step (S10), the damaged mold to be regenerated is prepared for regeneration by removing foreign substances through cleaning.

In the pretreatment step (S20), the damaged mold is quenched and tempered.

Heating equipment and cooling equipment are used to perform the quenching and tempering in the pretreatment step (S20).

Quenching is the process of rapidly cooling a metal heated to a high temperature to prevent deformation to obtain high strength or other properties. The damaged mold is heated to an appropriate temperature above the transformation point and then rapidly cooled in an appropriate quenching agent.

Tempering increases the hardness of a metal by quenching it, but makes it brittle, so it is reheated to an appropriate temperature and cooled in air to soften and stabilize the structure, thereby reducing internal stress and imparting toughness. After quenching the damaged mold, some or all of the changes that will occur as the temperature decreases can be prevented by rapid cooling, and the prevented changes can be allowed to proceed to an arbitrary state by heating again at a relatively low temperature for an appropriate period of time.

The short peening step (S30) removes cracks, scratches, etc. damaged in the mold by striking the pre-treated damaged mold surface with peening balls at high speed, and applies residual stress to the mold surface to improve surface strength and Increases fatigue strength.

The shot peening is performed by spraying small particles called pinning balls onto the surface of the damaged mold at a speed of 20 to 80 m/sec using an impeller and performing cold working to provide compressive residual stress and fill the damaged area where cracks or scratches have occurred. Compress to remove cracks or scratches.

In the shot peening, a type of pinning ball with appropriate strength, size, and material is selected depending on the material of the damaged mold and usage conditions (material of molten metal, temperature, supply cycle, etc.).

The shot peening operation can be performed once or more than twice. And when performing shot peening work multiple times, the type of pinning ball used for each work can be changed.

The shot peening equipment that performs the shot peening includes a sorter that selects and supplies pinning balls of a certain size, an impeller that projects the pinning balls to the damage mold at high speed, a feeder that supplies the pinning balls selected in the sorter to the impeller, and a damage part that supplies the pinning balls to the impeller. It includes a table on which the mold is mounted and rotated or transported so that the pinning ball projected from the impeller hits the damaged mold, and a controller that controls the selector, feeder, impeller, and table.

The supply amount of pinning balls from the feeder, the rotation speed and projection angle of the impeller, the transfer or rotation speed of the table, and the exposure time to the projected pinning balls are monitored and controlled by the controller.

The impeller is built into a housing, and the housing is provided with an inlet for receiving pinning balls from the feeder and an outlet for spraying pinning balls onto the table on which the damaged mold is mounted.

In the ion nitriding step (S40), a high voltage is applied to the metal workpiece in a vacuum nitrogen gas environment to form a nitride layer on the surface.

When a high voltage is applied to a metal workpiece in a nitrogen gas environment in a vacuum, the ionized nitrogen gas collides with the metal workpiece and changes kinetic energy into heat energy. In this process, the workpiece is heated and a strong nitride layer is formed on the surface.

As a nitride layer is formed on the surface of the workpiece (i.e., damaged mold), microcracks generated on the surface of the workpiece during the shot peening step are removed, and the nitride layer improves the wear resistance, corrosion resistance, and fatigue strength of the workpiece.

The ion nitriding step (S40) uses plasma equipment. The plasma equipment has a vacuum chamber, and the vacuum chamber is equipped with an injector to create a vacuum environment by injecting nitrogen, and a discharge electrode to discharge high pressure. Among the discharge electrodes, the cathode is connected to the damaged mold.

In the shot peening equipment that performs the shot peening step (S30), the outlet of the housing built into the impeller is deformed by colliding with a pinning ball projected at high speed, and when deformation occurs, it affects the projection angle to the damage mold, causing damage. It causes unevenness in the surface treatment of the mold.

Therefore, the outlet is detachably coupled to the housing in which the impeller is built for maintenance and replacement. Bolts and nuts are generally used to attach and detach the housing and the outlet. However, general bolts and nuts are gradually loosened by the impact of the pinning ball colliding with the outlet, and when the bolt and nut are loosened, the projection angle of the pinning ball through the outlet is affected.

Accordingly, the present invention uses a bolt member (B) and a nut member (N) in which loosening prevention means are introduced as bolts and nuts that fasten the housing 10 and the outlet 20.

Hereinafter, the bolt member (B) and the nut member (N) having loosening prevention means will be described with reference to Figure 2.

The bolt member (B) is composed of a head (B11) and a pin portion (B12), and a drawing hole (B13), a receiving groove (B14), and a tool groove (B15) are formed in the vertical direction from the bottom.

The core member (B2) is inserted through the outlet hole (B13) so that it can be drawn in and out of the lower part of the bolt member (B).

The head (B22) of the core member (B2) is elastically supported by the first spring (B23) embedded in the receiving groove (B14) of the bolt member (B), so that the core member (B2) has a force to move in the upward direction. receive The head B22 of the core member B2 can move up and down in the receiving groove B14 and the tool groove B15 of the bolt member B.

At the lower end of the core member (B2), locking pieces (B21) are provided that are pivotably hinged and elastically supported to rotate upward. A torsion spring can be used to elastically support the locking piece (B21) so that it rotates upward.

The locking piece B21 has a length that protrudes outward from the pin portion 12 of the bolt member B when unfolded in the horizontal direction, and its end may be sharp.

The nut member (N) has a fastening hole (N1) formed therein into which the pin portion (B12) of the bolt member (B) is inserted and fastened, and the lower part of the fastening hole (N1) is blocked.

A screw tab is formed on the inner wall of the fastening hole (N1) so as to be screwed together with a screw thread formed in the pin portion (B12) of the bolt member (B).

A pressure plate (N2) is built into the lower side of the fastening hole (N1), and the pressure plate (N2) is elastically supported by a second spring (N3) and receives a force to move upward. A screw tab may not be formed on the lower side of the inner wall of the permanent fastening hole (N1) to enable smooth raising and lowering of the pressure plate (N2) and to limit the lifting range.

Referring to [B] in Figure 2, when a tool (1) such as a driver is inserted into the tool groove (B15) of the bolt member (B), the head (B22) of the core member (B2) is inserted into the tool (1). When pressed, the core member (B2) is lowered, and the lower end of the core member (B) is pulled out from the pin portion (B12) of the bolt member (B), and accordingly, a locking piece coupled with a hinge and elastic support to the lower end of the ten member (B) (B21) rotates upward so that the end of the stopper piece (B21) is located inside the pin portion (B12) of the bolt member (B), so that the bolt member (B) connects to the fastening hole (N1) of the nut member (N). The part (B21) that is inserted into the screw connection box does not interfere.

Referring to [C] in Figure 2, after fastening the bolt member (B) to the nut member (N) using the tool (1) and then removing the tool (1), the first spring (B23) is attached to the core member ( A force is applied to move B2) upward, and the pressure plate N2 exerts a force to push the lower end of the core member B2 and the locking pieces B21 upward by the second spring N3.

In this way, due to the force of the core member (B2) to rise and the force that pushes the pressure plate (N2) upward, the pressure pieces (B21) are spread horizontally and the ends are pressed into the inner wall of the fastening hole (N1) of the nut member (N). do.

As the ends of the pressure pieces (B21) are embedded in the inner wall of the fastening hole (N1), the rotation of the nut member (N) of the bolt member (B) is restricted, so that even if an impact is applied, the bolt member (B) is N) becomes unsolvable. Therefore, the wire or cable pressed between the bolt member (B) and the nut member (N) does not come loose.

On the other hand, when the tool (1) is inserted into the tool groove (B15), the core member (B2) is lowered and the pressure pieces (B21) are separated from the inner wall of the fastening hole (N1) and are inside the pin portion (B12) of the bolt member (B). By moving, the bolt member (B) can be easily separated from the nut member (N).

In the above description of the present invention, with reference to the accompanying drawings, a specific procedure and a surface treatment method for regenerating a damaged mold having a specific shape and structure and a sleeve thereof surface-treated accordingly have been described. However, the present invention has been described by those skilled in the art. Various modifications and changes are possible, and such modifications and changes should be construed as falling within the scope of protection of the present invention.

S10: Preparation step S20: Preprocessing step
S30: Shot peening step S40: Ion nitriding step

Claims (4)

A pretreatment step of performing pretreatment on the damaged mold;
In the surface treatment method for regenerating a damaged mold comprising a short peening step of performing short peening on the pre-treated damaged mold,

The shot peening equipment that performs the shot peening step includes an impeller that sprays peening balls into the damaged mold at high pressure, a housing that houses the impeller, an inlet provided in the housing to supply peening balls to the impeller, and a damaged mold. It includes an outlet for spraying into,
The outlet is detachably fastened to the housing through a bolt member and a nut member having a loosening prevention structure,

A drawing hole, a receiving groove, and a tool groove are formed in the vertical direction of the bolt member,
A core member is inserted into the outlet hole, a lower end of the core member is hinged with locking pieces elastically supported to rotate upward, and a first spring is provided in the receiving groove to elastically support the head of the core member upward. Built-in,
A pressure plate elastically supported by a second spring is built into the fastening hole of the nut member,
When a tool is inserted into the tool groove of the bolt member, the head of the core member is lowered by being pressed by the tool, and the locking pieces are rotated upward so that the end is located inside the pin portion of the bolt,
When the bolt member is fastened to the nut member, the locking pieces are spread by the force to move the core member upward by the first spring and the force to push the pressure plate by the second spring, so that the ends are connected to the nut member. A surface treatment method for regenerating a damaged mold, characterized in that it is driven into the inner wall of the fastening hole. According to claim 1,
A surface treatment method for regenerating a damaged mold further comprising an ion-nitriding step of ion-nitriding the damaged mold that has been subjected to shot peening. delete delete

Images