KR101399981B1 - Connecting member in handpiece and method for fabricating the same - Google Patents

Abstract

Disclosed are a handpiece connector in which a plastic material and a metallic material are integrated by insert molding and a manufacturing method thereof. The disclosed handpiece connector includes a ring-shaped body unit coupling unit which connects the end of a handpiece body unit, a ring-shaped head unit coupling unit which is spaced from the body unit coupling unit and connects the end of a handpiece head unit, and a plastic connection unit which connects the body unit coupling unit to the head unit coupling unit. The plastic connection unit is formed by injection molding. The body unit coupling unit, the plastic connection unit, and the head unit coupling unit are integrally coupled. A through hole penetrates the body unit coupling unit, the plastic connection unit, and the head unit coupling unit.

Description

The connecting member of the hand piece and the manufacturing method thereof

The present invention relates to a part constituting a handpiece used for elaborate manual work in the field of dental treatment, for example, and a manufacturing method thereof.

In the field of dental treatment, for example, elaborate manual operations are performed using handpieces. Examples of dental treatment handpieces are disclosed in Korean Patent Application No. 10-2006-7012759. FIG. 1 is a side view showing a conventional handpiece for dental treatment. Referring to FIG. 1, the handpiece 1 for dental treatment includes a tool 9 for polishing, cutting, or perforating a tooth by rotating at a high speed, A head unit 7 that rotatably supports the head unit 7 and a body unit 2 that is cylindrical in shape so as to be held by a worker and a head unit 7 and a body unit 2 (4) and a head unit fixing member (6). Specifically, the connecting member 4 is connected to the front end portion of the body unit 2, and the head unit fixing member 6 fixes the head unit 7 to the connecting member 4. [

The handpiece 1 for dental treatment is configured such that the connecting member 4 is bent so that an operator can easily insert the head unit 7 into the mouth of a patient and work, But it is composed of an assembly including three members. In order to maintain the rigidity of the bent portion of the assembly including the conventional connecting member 4, all of the three members are formed of stainless steel, and the female and male screw threads are formed and screwed together with each other. Specifically, it was necessary to form the three member shapes, to machine the female and male screw treads by the precision machining on the corresponding joints, and to perform the turning operation for screw engagement. Therefore, manufacturing costs have increased due to increased material costs, processing costs, and processing time.

The present invention provides a connecting member for a handpiece, in which a plastic material and a metal material are integrated by insert injection, and a method of manufacturing the same.

The present invention also relates to a connecting member for a handpiece, which can be manufactured without a process of precisely machining female and male screw treads on parts and a process in which the female and male screw tread-formed parts are rotated and joined together, and a method of manufacturing the same .

The present invention relates to a member for connecting a body unit and a head unit of a handpiece such that the axes of both members are not coincident with each other, A body unit coupling portion, another annular head unit coupling portion which is located apart from the body unit coupling portion and in which an end portion of the head unit is inserted and connected, and a plastic coupling portion which connects the body unit coupling portion and the head unit coupling portion, Wherein the plastic connection portion is formed by injection molding so that the body unit coupling portion, the plastic coupling portion, and the head unit coupling portion are integrally coupled, and the body unit coupling portion, the plastic coupling portion, and the head unit coupling And a through hole passing through the through hole is formed.

The body unit coupling portion and the head unit coupling portion may be formed of a metal material, and the injection molding material of the plastic coupling portion may be formed by mixing synthetic resin and glass fiber.

The outer circumferential surface of the body unit engaging portion and the outer circumferential surface of the head unit engaging portion may be provided with concavities and convexities such that the area of contact with the plastic connecting portion is enlarged.

The present invention also provides a method of manufacturing a handpiece connecting member for connecting a body unit and a head unit of a handpiece such that the axes of the handpiece and the head unit are not coincident with each other, A mounting step of mounting the coupling parts and other annular head unit engaging parts on the lower mold so as to be spaced apart from each other, the first sliding core passing through the body unit engaging part, the second sliding core passing through the head unit engaging part, A sliding core moving step of moving the first sliding core and the second sliding core toward each other such that the first sliding core and the second sliding core are brought into contact with each other between the engaging part and the head unit engaging part, And fixing the head unit engaging portion between the upper mold and the lower mold; It provides a mold part and a manufacturing method of a hand piece linking member for the injection molding material is injected between the lower mold having an injection material to form a plastic connection portion connecting the body portion and the head unit coupled to the joint unit.

According to the present invention, the head unit engaging portion of the metal material and the body unit engaging portion of the metal material are integrally joined to the intermediate connecting portion of the plastic material by insert injection, thereby forming the connecting member. Therefore, it is possible to manufacture the parts without any process of precisely machining the female and male screw treads and the parts with the female and male screw treads, so that the quality of the worker and the quality of the machining apparatus Can be minimized, costs can be reduced, and productivity is improved.

1 is a side view showing an example of a conventional handpiece for dental treatment.
2 is a cross-sectional view illustrating a portion of a handpiece including a connecting member according to an embodiment of the present invention.
3 and 4 are a cross-sectional view and a perspective view showing the connecting member of Fig.
5 is a plan view showing a lower mold of an insert injection mold for manufacturing a connection member according to an embodiment of the present invention.
6 to 8 are sectional views sequentially illustrating a method of manufacturing a connecting member according to an embodiment of the present invention.

Hereinafter, a connecting member for a handpiece according to an embodiment of the present invention and a method of manufacturing the same will be described in detail with reference to the accompanying drawings. The terminology used herein is a term used to properly express the preferred embodiment of the present invention, which may vary depending on the intention of the user or operator or the custom of the field to which the present invention belongs. Therefore, the definitions of these terms should be based on the contents throughout this specification.

FIG. 2 is a cross-sectional view illustrating a portion of a handpiece including a connecting member according to an embodiment of the present invention, and FIGS. 3 and 4 are a cross-sectional view and a perspective view showing the connecting member of FIG. 2 to 4, a connecting member 30 of a handpiece according to an embodiment of the present invention includes a body unit 11 serving as a body of a dental treatment handpiece 10, 9) (see Fig. 1) to the head unit 20 for supporting the head unit 20 at a high speed. The connecting member 30 has a body unit engaging portion 31, a head unit engaging portion 40, and a plastic connecting portion 47.

The body unit coupling portion 31 is inserted into and connected to the bearing 15 of the front end portion of the body unit 11 in a ring shape. The bearing 15 is constrained to the inner peripheral surface of the body unit engaging portion 31 so that the body unit 11 is fixedly coupled to the connecting member 30. [ The head unit engaging portion 40 is inserted into and connected to the rear end of the head unit 20 in a ring shape different from that of the body unit engaging portion 31. [ The shaft 23 of the head unit 20 is inserted into the head unit engaging portion 40 and the head unit connecting member 25 put on the outside of the head unit engaging portion 40 is operated to move the head unit 20 And is fixedly coupled to the connecting member (30). The head unit engaging portion 40 is spaced apart from the body unit engaging portion 31. [ The head unit engaging portion 40 and the body unit engaging portion 31 are formed of a metal material such as stainless steel for maintaining stiffness.

The plastic connecting portion 47 connects the body unit engaging portion 31 and the head unit engaging portion 40 which are spaced apart from each other. The plastic connecting portion 47 is formed by injection molding in which the molten material is injected into the mold. Specifically, the body unit engaging portion 31 and the head unit engaging portion 40, which are previously prepared in the mold, Called " insert injection " in which the material is injected into the mold. A more specific production method will be described later. The injection molding material of the plastic connection portion 47 may be formed by mixing synthetic resin and glass fiber so as to have a rigidity comparable to that of a metal material. For example, a polyamide resin mixed with 30% (by weight) glass fibers may be used.

The concave and convex portions 42 are formed on the outer circumferential surface of the head unit engaging portion 40 so as to increase the bonding area between the plastic connecting portion 47 and the head unit engaging portion 40 and increase the engaging force. The concave and convex portions 33 are also formed on the outer circumferential surface of the body unit engaging portion 31 so that the joining area between the plastic connecting portion 47 and the body unit engaging portion 31 is enlarged and the engaging force is increased.

The plastic connecting portion 47 is formed by injection molding so that the body unit engaging portion 31, the plastic connecting portion 47, and the head unit engaging portion 40 are integrally joined. The connecting member 30 has a through hole 50 passing through the body unit engaging portion 31, the plastic connecting portion 47, and the head unit engaging portion 40. The head unit engaging portion 40 is slantly connected to the body unit engaging portion 31 by the plastic connecting portion 47. The body unit 11 and the head unit 20 are connected so that the axis L1 of the body unit 11 and the axis L2 of the head unit 20 do not coincide with each other.

The front end portion of the body unit shaft 17 extending along the axial line L1 in the body unit 11 is inserted into the through hole 50 in the body unit 11 And then passes through the body unit coupling portion 31. When the head unit 20 is fixedly coupled to the head unit engaging portion 40, the rear end portion of the head unit shaft 23 extending along the axis L2 in the head unit 20 moves along the through hole 50 And penetrates through the head unit engaging portion 40. The front end portion of the body unit shaft 17 and the rear end portion of the head unit shaft 23 are connected to each other at the intersection of the two axial lines L1 and L2 so that when the body unit shaft 17 rotates, (23).

FIG. 5 is a plan view showing a lower mold of an insert injection mold for manufacturing a connection member according to an embodiment of the present invention, and FIGS. 6 to 8 are sectional views sequentially showing a method of manufacturing a connection member according to an embodiment of the present invention . 6 to 8 are cross-sectional views cut along the line S-S of FIG. 5 to 8, the insert injection mold 60 used for manufacturing the connecting member 30 (see FIG. 3) includes a lower mold 72, a lower mold 72, a lower mold 72, And an upper mold 61 rising up to be spaced apart from the upper mold 72. The lower mold 72 includes a lower plate 73 and a lower core 74 inserted and fixed on the upper surface of the lower plate 73. The upper mold 61 includes an upper plate 62, And an upper core 63 inserted and fixed to the lower surface of the upper plate 62.

The upper surface of the lower core 74 and the lower surface of the upper core 63 respectively have body unit engaging portion fixing grooves 66 and 77 corresponding to the outer peripheral surface shape of the body unit engaging portion 31, The head unit engaging portion fixing grooves 68 and 79 corresponding to the outer circumferential surface shape of the plastic connecting portion 40 and the cavity grooves 70 and 81 corresponding to the outer circumferential surface shape of the plastic connecting portion 47 are engraved. The body unit engaging portion 31 and the head unit engaging portion 40 are mounted on the body unit engaging portion fixing groove 77 and the head unit engaging portion fixing groove 79 of the lower core 74 respectively and the upper mold 61 Is lowered toward the lower mold 72 so that the lower surface of the upper core 63 is brought into close contact with the upper surface of the lower core 74 so that the cavity grooves 70 and 81 of the upper mold 61 and the lower mold 72 A cavity is formed in which the space is limited. The cavity is a place where the molten material is injected and cooled and cured. Reference numeral 84 in FIG. 5 is a gate for guiding the molten material injected into the mold 60 from the outside of the mold 60 to the cavity by an injection device (not shown).

The first and second sliding cores 93 and 99 are provided on the lower mold 72 so that the through hole 50 can be formed in the connecting member 30. [ The first and second sliding cores 93 and 99 are in the shape of a stick extending in the horizontal direction. The first sliding core 93 includes a first diameter portion 94 having the same diameter as the inner diameter ID1 of the first inner circumferential surface 35 of the body unit engaging portion 31 And a second diameter portion 95 having the same diameter as the inner diameter ID2 (see Fig. 3) of the second inner circumferential surface 36 of the second connecting portion 31 are connected in series. The inner diameter (ID1) of the first inner circumferential surface (35) is larger than the inner diameter (ID2) of the second inner circumferential surface (36).

The first sliding core (93) is fixedly supported by the first sliding block (90). A first inclined pin inserting hole 91 is formed on the upper side of the first sliding block 90 and a second inclined pin inserting hole 91 is formed in the upper mold 61. The first inclined pin inserting hole 91 1 Lean pins (not shown) are projecting downward at an angle. The first inclined fin is inserted into the first inclined fin insert hole 91 more deeply as the upper mold 61 descends and approaches the lower mold 72 and the first sliding block 90 is inserted into the body unit engaging portion fixing groove And moves toward the body unit engaging portion 31 which is seated on the body portion 77. 7, the first sliding core 93 is inserted into the body unit engaging portion 31 so that the first diameter portion 94 is engaged with the lower core 74, The second diameter portion 95 is in face-to-face contact with the second inner circumferential surface 36 and the distal end of the second diameter portion 95 penetrates the body unit engaging portion 31 to be engaged with the head unit engaging portion 40 . When the upper mold 61 is lifted away from the lower mold 72, the first sliding block 90 and the first sliding core 93 supported thereon are moved horizontally in the direction away from the body unit engaging portion 31, Move.

The second sliding core 99 is a cylindrical stick having the same diameter as the inner diameter ID3 (see Fig. 3) of the third inner circumferential surface 44 of the head unit engaging portion 40. The inner diameter of the third inner circumferential surface 44 (ID3) is smaller than the inner diameter (ID1) of the first inner circumferential surface (35) and the inner diameter (ID2) of the second inner circumferential surface (36). The second sliding core 99 is fixedly supported by the second sliding block 97. A second inclined pin inserting hole 98 is formed on the upper side of the second sliding block 99 as in the case of the first sliding block 90 and the second inclined pin inserting hole 98 is formed in the upper mold 61, (Not shown) that can be inserted into the tapered pin insertion hole 98 are projected downwardly in an inclined manner. As the upper mold 61 descends and approaches the lower mold 72, the second inclined fin is inserted into the second inclined fin insertion hole 98 more deeply and the second sliding block 97 is inserted into the head unit engaging portion fixing groove And moves toward the head unit engaging portion 40 that is seated in the engaging portion 79. 7, the second sliding core 99 is inserted into the head unit engaging portion 40 so that the upper end of the head unit engaging portion 40 And the distal end thereof is brought into contact with the distal end of the first sliding core 93 which is in contact with the head unit engaging portion 40 through the body unit engaging portion 31 . When the upper mold 61 is lifted away from the lower mold 72, the second sliding block 97 and the second sliding core 99 supported thereon are moved horizontally Move. When the molten material is injected into the cavity defined by the cavity grooves 70 and 81 while the distal end of the first sliding core 93 and the distal end of the second sliding core 99 are in contact with each other, A through hole 50 corresponding to the first sliding core 93 and the second sliding core 99 is formed.

Hereinafter, a method of manufacturing the connecting member 30 (see Fig. 3) according to the embodiment of the present invention will be described in detail with reference to Figs. 5 to 8. Fig. The method of manufacturing the connecting member 30 includes a mounting step, a sliding core moving step, a fixing step, a material injecting step, and a taking-out step. 5 and 6, the mounting step is a step of mounting the body unit engaging part 31 and the head unit engaging part 40 in the lower mold 72 so as to be spaced apart from each other. Specifically, when the upper mold 61 and the lower mold 72 are separated from each other and the first and second sliding cores 93 and 99 are spaced apart from the cavity groove 81 of the lower mold 72, The body unit engaging portion 31 and the head unit engaging portion 40 are seated in the body unit engaging portion fixing groove 77 and the head unit engaging portion fixing groove 79 of the main body unit 72, respectively.

5 and 7, in the sliding core moving step, the first sliding core 93 passes through the body unit engaging portion 31 and the second sliding core 99 passes through the head unit engaging portion 40 So that the second sliding core 93 and the second sliding core 99 are brought close to each other so as to be in contact with each other between the body unit engaging portion 31 and the head unit engaging portion 40. [ The fixing step is a step of bringing the upper mold 61 into close contact with the lower mold 72 to cause the body unit engaging portion 31 and the head unit engaging portion 40 to move between the upper mold 61 and the lower mold 72, Respectively.

The sliding core moving step and the fixing step are substantially simultaneously performed by lowering the upper mold 61 so that the upper core 63 and the lower core 74 are in close contact with each other. That is, when the upper mold 61 is lowered, the body unit engaging portion fixing groove 66 and the head unit engaging portion fixing groove 68 of the upper core 63 are engaged with the body unit engaging portion 31 and the head unit engaging portion 40 And the cavity grooves 70 of the upper core 63 are sandwiched between the protrusions 31 and 40 so that the body unit engaging portion 31 and the head unit engaging portion 40 are not moved. And a cavity defined by the cavity groove 81 of the lower core.

As the upper mold 61 is lowered, the first and second tilting pins (not shown) are inserted into the first and second tilting pin insertion holes 91 and 98 and the first and second sliding blocks 90 and 97 to move the first sliding core 93 and the second sliding core 99 close to each other. When the upper core 63 is in close contact with the lower core 74, the first sliding core 93 and the second sliding core 99 penetrate the body unit engaging portion 31 and the head unit engaging portion 40, respectively, The distal end of the first sliding core 93 and the distal end of the second sliding core 99 in the cavity are contacted and connected to each other.

The material injecting step injects the molten injection molding material into the cavity between the upper mold 61 and the lower mold 72 to inject the plastic connecting portion 47). The molten injection molding material flows into the mold 60 from the outside of the insert injection mold 60 through a sprue (not shown) and is discharged to the gate 84 through a runner (not shown) , And flows into the pair of cavities (see FIG. 5) through the gate 84. When the injection molding material is cooled and cured in the mold 60, the connecting member 30 (see Fig. 3) in which the plastic connecting portion 47, the body unit engaging portion 31 and the head unit engaging portion 40 are integrated .

5 and 8, the taking-out step raises the upper mold 61 to separate the upper mold 61 and the lower mold 72, separates the connecting member 30 from the lower mold 72, . As the upper mold 61 moves upward, the first and second sliding cores 93 and 99 return to their original positions and are spaced apart from each other. The connection member 30 exposed on the lower core 74 can be taken out of the mold 60 by the human operator's power or by an industrial robot and stored in a specific place. Although not shown, a process of easily separating the connecting member 30, which is stuck to the lower core 74, from the lower core 74 by using a milky pin (not shown) may be added.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it will be understood by those skilled in the art that various changes and modifications may be made without departing from the scope of the present invention. Therefore, the true scope of protection of the present invention should be defined only by the appended claims.

30: connecting member 31: body unit coupling portion
40: head unit engaging portion 47: plastic connecting portion
60: insert injection mold 63: upper core
74: lower core 93, 99: sliding core

Claims (5)

As a member for connecting the body unit and the head unit of the handpiece so that the axes of the handpieces do not coincide with each other,
An annular body unit engaging portion to which an end of the body unit is inserted and connected;
An annular head unit engaging portion located apart from the body unit engaging portion and having an end portion of the head unit inserted and connected; And
And a plastic connection portion connecting the body unit coupling portion and the head unit coupling portion,
Wherein the plastic connecting portion is formed by injection molding so that the body unit connecting portion, the plastic connecting portion, and the head unit connecting portion are integrally joined,
Wherein the body unit coupling portion, the plastic coupling portion, and the through hole penetrating the head unit coupling portion are formed. The method according to claim 1,
Wherein the body unit coupling portion and the head unit coupling portion are made of a metal material,
Wherein the injection molding material of the plastic connection part is formed by mixing synthetic resin and glass fiber. The method according to claim 1,
Wherein an outer circumferential surface of the body unit engaging portion and an outer circumferential surface of the head unit engaging portion are formed with concavities and convexities such that the joining area with the plastic connecting portion is enlarged. A method of manufacturing a handpiece connecting member for connecting a body unit and a head unit of a handpiece such that the axes of the handpiece and the head unit are not coincident with each other,
A mounting step of mounting the annular body unit engaging part and the annular head unit engaging part in the lower mold so as to be spaced apart from each other;
The first sliding core is passed through the body unit engaging portion and the second sliding core penetrates through the head unit engaging portion so that the first sliding core and the second sliding core come into contact with each other between the body unit engaging portion and the head unit engaging portion, A sliding core moving step of moving the sliding cores toward each other;
Fixing the upper body mold to the lower mold to fix the body unit engaging portion and the head unit engaging portion between the upper mold and the lower mold; And
And injecting an injection molding material between the upper mold and the lower mold to form a plastic connection portion connecting the body unit coupling portion and the head unit coupling portion. Way. 5. The method of claim 4,
Wherein the body unit coupling portion and the head unit coupling portion are made of a metal material,
Wherein the injection molding material of the plastic connection part is formed by mixing synthetic resin and glass fiber.

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