JPH1037548A - Key manufacturing method and key metal powder injection molding apparatus - Google Patents

Abstract

(57) [Problem] To integrally produce a key including a key mountain shape by metal powder injection molding. SOLUTION: A molding die having a fixed die and a movable die arranged opposite to the fixed die is provided in an injection molding machine, and a mixture of metal powder and resin is melted in a cavity formed in the molding die. The key is manufactured using a metal powder injection molding method that is injected in a state and the molded product is taken out of the cavity after the resin is cured. During manufacture, each of the plurality of sliders is individually moved within the gap of the mold with respect to the cavity of the mold to determine the shape of the cutout of the key to be manufactured, and then the injection of the injection molding machine is performed. A mixture of the metal powder and the resin is injected into the cavity in a molten state of the resin by a machine, and after the resin is cured, the molded product is taken out of the cavity, and then the molded product is heated and sintered.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a key manufacturing technique, and more particularly to a key manufacturing method and a key manufacturing apparatus using a metal powder injection molding method.

[0002]

2. Description of the Related Art Conventionally, keys for locking or unlocking a locking device have been manufactured by various methods. For example, first
A blank key consisting of a head portion and a blade portion is punched out from a metal coil material such as brass by pressing. Next, in order to give a desired cross section to the key, a groove is formed in the blade portion along the length direction by cutting. Subsequently, after performing chrome plating on the surface of the blank key, the blade portion is subjected to mountain cutting to form a notch for giving a key code. Finally, the burr is removed from the blank key to form a metal key. In each process, blank keys and keys are required to have an accuracy of 10 μm.

[0003] Also, Japanese Patent Publication No. 59-8463 discloses that
Extrude a bar-shaped material to form a flat foot, then crush it to form a flat head, then shear the key contour shape, and finally form the flat foot to the outside key shape The key processing method is shown. In the conventional keying method, the notch forming, key ridge forming, and deburring steps are performed by cutting. However, in the keying method described in the above publication, these steps can be performed by pressing, shearing, or omitted. Therefore, the integrated automatic processing from the material to the product becomes possible, and the steps after the head crushing processing can be efficiently processed by the transfer press or the like, so that the productivity is remarkably improved.

On the other hand, Japanese Patent Publication No. 5-61012 discloses that
There has been proposed a key formed by laminating a plurality of thin plates in a predetermined order and integrally fixing them. When manufacturing this key, a reference thin plate and a predetermined number of laminated thin plates are punched from a material, and an engagement concave portion is formed in the reference thin plate, and an engaging concave portion and an engaging convex portion are formed in each laminated thin plate. Form. Next, a fixing step in which a predetermined number of laminated thin plates are fixed to the reference thin plate by successively engaging the respective engaging projections with the respective engaging recesses between the two adjacently stacked thin plates and fixing the same. Do. This makes it easy to manufacture one laminated key, eliminating the need for a conventional cutting step, and improving productivity.

[0005]

By the way, in the conventional key formation, it has been proposed to perform an injection molding method using a resin material or a casting method of a metal material from the viewpoint of improving productivity and saving materials. . For example, Japanese Utility Model Application No. 54-1712
No. 70 (Japanese Utility Model Application Laid-Open No. 56-87255) discloses an example in which a key formed by die casting is used for a key switch of an electronic cash register. However, since this specification does not disclose a technique for giving a key a different key code and does not show how to change the key code to manufacture a key, a large number of keys are manufactured. It cannot be used as a normal key with a key code.

In addition, in the injection molding method and the casting method, it is necessary to form key ridges for giving different key codes individually. However, conventionally, key ridges cannot be formed by the injection molding method or the casting method. Since the key peaks are formed by cutting after casting, the improvement in productivity is insufficient. In addition, when a key is formed by injection molding using a resin material, the mechanical strength of the key is not sufficient, and there is a risk that the key hill may be damaged due to long-term use and become unusable. Also,
If a key is formed by casting using a metal material, a key with sufficient mechanical strength can be manufactured, but the casting equipment becomes large and the mold is severely deteriorated, and the key mountain must be formed by cutting. However, sufficient productivity was not necessarily obtained.

It is an object of the present invention to provide a key manufacturing method and a metal powder injection molding apparatus for a key capable of integrally producing a key including a key mountain shape.

[0008]

According to a method of manufacturing a key according to the present invention, a molding die having a fixed die and a movable die disposed opposite to the fixed die is provided in an injection molding machine and formed in the molding die. Cavity In a metal powder injection molding method, a mixture of metal powder and resin is injected into the cavity in a molten state of the resin, and the molded product is removed from the cavity after the resin is cured.
A step of individually moving each of the plurality of sliders within the gap of the molding die with respect to the molding die to determine the shape of the cutout portion of the key to be manufactured; And a step of injecting the mixture into the cavity in a molten state of the resin, a step of removing the molded product from the cavity after the resin is cured, and a step of heating and sintering the key removed from the cavity.

In the embodiment of the present invention, the step of removing unnecessary portions of the molded product taken out of the cavity, the step of removing resin that imparts fluidity at the time of molding from the key taken out of the cavity, or moving each slider horizontally. The slider moves and arranges one of a plurality of tips provided at an end of the slider in a gap formed between the fixed mold and the movable mold, and the gap of the mold with respect to the cavity formed in the mold. Within each of the plurality of sliders to determine the shape of the cutout of the key to be manufactured.

In the present invention, if the molded product taken out of the cavity has sufficient mechanical strength, the molded product may be taken out of the cavity and used as a key after curing of the resin without heating and sintering.

According to the metal powder injection molding apparatus for a key according to the present invention, a molding die having a fixed die and a movable die disposed opposite to the fixed die is provided in the injection molding machine, and the metal powder is injected into the cavity of the molding die. In a metal powder injection molding apparatus, in which a mixture with a resin is injected in a molten state of a resin and a molded product is taken out from a cavity after the resin is cured, a notch portion of a key is formed in a gap of the mold with respect to a cavity formed in the mold. A plurality of sliders arranged at positions corresponding to, and a vertical moving device for individually moving and fixing the sliders within the gap of the mold with respect to the cavity formed in a shape complementary to the shape of the key, After each slider is moved to a predetermined position by the vertical moving device, a mixture of metal powder and resin is injected into the cavity to perform injection molding. The vertical moving device includes a cam that presses each slider and changes the amount of protrusion of the slider with respect to the cavity, a spring that presses each slider against the cam, and a motor that rotates each cam. A plurality of sliders are provided on both sides of the cavity.

In the present invention, each of the plurality of sliders is individually moved within the gap of the mold with respect to the cavity formed in the mold to determine the shape of the cutout of the key to be manufactured. Keys having notches of different shapes corresponding to a plurality of key codes can be formed easily and quickly by injection molding, and the obtained keys have sufficient mechanical strength. Further, according to the present invention, keys can be integrally produced with high precision in a short time by metal powder injection molding.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of a key manufacturing method and a key metal powder injection molding apparatus according to the present invention is shown in FIG.
8 will be described.

As shown in FIG. 1, a key manufacturing apparatus 1 according to the present invention includes a fixed mold 3 having a runner 8a and a gate 8 connected to the runner 8a, and a movable mold 4 arranged to face the fixed mold 3. And a molding die 2 which constitutes a die having the following. FIG. 3 shows a front view of the fixed mold 3, and FIG. 4 shows a plan view of the mold 2. As shown in FIG. 1, a slider 6 is disposed in a gap 2a formed between the fixed die 3 and the movable die 4, and each slider 6 has a substantially L-shape including a linear portion 6a and a bent portion 6b. Formed. As shown in FIG. 2, a pair of sliders 6 are arranged substantially symmetrically with respect to a cavity 5 formed by the fixed mold 3 and the movable mold 4. As shown in FIG. 1, the bent portion 6 b of the slider 6 is pressed against the cam 9 by the spring 7. Four projecting portions 9a to 9d are formed on the smooth circumferential surface of the cam 9 in order to give four steps to the cutout portion of the key. The cam 9 has a through hole 10.
And the groove 1 connected to the through hole 10 and at an angular interval of 90 degrees.
1 is formed. A hollow shaft 12 is disposed in the through hole 10, and the projection 1 fixed to the hollow shaft 12 and protruding in the radial direction is provided.
3 is engaged with the groove 11 of the cam 9.

As shown in FIG. 4, on one side of the hollow shaft 12, a motor 20 for rotating the hollow shaft 12 is provided.
0 and the rotation of the motor 31 are controlled by the controller 21. The cam 9, the motor 20, the motor 31, and the controller 21 individually constitute a vertical moving device 22 that moves and fixes each slider 6 within the gap 2a. The hollow shaft 12 is rotatably mounted as an output shaft of the motor 20, and is rotatably mounted on a pair of guides 33.
A rack 30 is attached to the housing (3), and the pinion 32 of the fixed motor 31 meshes with the rack 30.
Therefore, when the motor 20 is driven, the hollow shaft 12 is rotated, and when the motor 31 is rotated, the pinion 32 is rotated. Therefore, the rack 30 and the motor 20 are moved together with the hollow shaft 12 to the cam 9 along the guide 33. It is moved so as to approach or separate from it. Thus, after the motor 20 is rotated to rotate the first cam to a predetermined angular position, the motor 31
Can be driven to move the hollow shaft 12 in the axial direction. Therefore,
After separating the hollow shaft 12 from the first cam 9 and engaging the second cam 9, the motor 20 is rotated to rotate the hollow shaft 1.
The second cam 9 meshing with the second cam 9 can be rotated to a predetermined angular position. By repeating this operation, all eight cams 9 can be rotated to predetermined angular positions. When each cam 9 is rotated to a predetermined position, the slider 6 is fixed at a predetermined position by the cam 9 and the spring 7.

As shown in FIG. 2, a cavity 5 having a shape complementary to the shape of the key is formed in the mold 2, and when manufacturing a key having eight tumblers, eight sliders 6 and cams 9 are provided.
Are placed adjacent to each other. The plurality of sliders 6 are arranged adjacent to each other and at positions corresponding to the notches of the key for providing the key code. A set of the slider 6 and the cam 9 is provided on both sides of the cavity 5, and the slider 6 is moved within the gap 2 a by the four protrusions 9 a to 9 d of the cam 9 to four different steps as shown by dotted lines 14. Is done. The pitch of the steps is, for example, 0.5 mm.
As shown in FIG. 3, in this embodiment, a molding die 2 is formed for taking two keys, and a molding material is supplied from a gate 8 to each cavity 5 to a pair of cavities 5 formed opposite to each other. Is done.

In the above configuration, with the mold 2 opened, the motors 20 and 31 of the vertical moving device 22 are alternately rotated to move the cams 9 to predetermined angular positions while moving the hollow shaft 12. By rotating, the slider 6 within the gap 2a is moved to a predetermined position. Next, the movable mold 4 is clamped to the fixed mold 3 to form the cavity 5. In this state, a molding material is supplied from the injection device 40 into the cavity 5. The molding material is Metal Injection Molding Pr
a mixture of powder metal having an average particle size of about 10 μm and 40 to 50% by volume of a resin used as a binder. Powdered metal is, for example, powdered zinc, aluminum, stainless steel (SUS316L,
SUS416L), pure iron or silicon-containing iron, an iron-nickel (Fe-Ni) alloy, an iron-cobalt (Fe-Co) alloy, or a combination thereof. In the present embodiment, zinc having a large cutting stress and excellent durability is used, or aluminum which is lightweight and can be easily polished and which can be plated. The resin material used as the binder is thermoplastic resin such as powdered polyethylene, polypropylene, atactic polypropylene, ethylene-vinyl acetate copolymer, polystyrene, vinyl acetate, vinyl chloride, polyacrylate, polymethacrylate, etc. Is done.
In practice, wax, plasticizer and lubricant are mixed with the metal powder and the resin powder. The powder metal and the powder resin are mixed, sufficiently kneaded, and then formed into a pellet. The pellet-shaped molding material (compound) is supplied from the hopper into the injection device, and the molding material in the injection device is sent to the tip portion by the screw and heated to be in a molten state. The metal powder injection molding apparatus including the injection apparatus and the molding die described in the present embodiment has a structure similar to that of a known resin injection molding apparatus except for the shape of the cavity 5.

As shown in FIG. 1, a cavity 5 is formed from a tip 41 of an injection device 40 through a runner 8a and a gate 8.
The molten molding material is press-fitted therein. After the resin in the cavity 5 is cured, the mold 2 is opened, and the molded product is taken out of the cavity 5. The key obtained as a molded product is composed of a mixture of metal and resin. If there are unnecessary portions such as burrs, unnecessary portions such as burrs are removed or trimmed by a polishing step or tumbling.

In order to remove (degrease) the resin (binder) imparted with fluidity during molding from the molded article, the molded article is heated in an inert gas to evaporate the resin, or the molded article is dissolved in a solution. The resin is dissolved by immersion to dissolve the resin.

To further increase the strength of the key, the key taken out of the cavity 5 is heated and sintered at a temperature of 1200 to 1400 ° C. in an inert gas atmosphere in a sintering furnace such as a vacuum furnace. Take it out of the furnace and trim the key. This sintering causes the key to undergo a large shrinkage of 13 to 20% in linear shrinkage. However, since the metal powder is uniformly filled in the mold, almost isotropic shrinkage is obtained, and the dimensional accuracy is ±
A high accuracy of 0.3% is possible, and at the same time a high sintering density is obtained due to the sintering of the fine particles.

Further, when decoration is required for the key, plating such as chrome plating is performed.

6 to 8 show another embodiment of the present invention. 6 to 8, the same parts as those shown in FIGS. 1 to 7 are denoted by the same reference numerals, and description thereof will be omitted.

As shown in FIGS. 6 and 7, the slider 6 is formed substantially in a T-shape, and two forked ends 6c and 6d of different shapes are provided at the bifurcated ends of the linear portion 6a. It is formed. One end 6c is formed into a substantially trapezoidal cross section by two chamfers 6e, and the other end 6d is formed with a chamfer 6e and a projection 6f. One end of the bent end 6b of the slider 6 is connected via a pin 52 to a plunger 51 of a push-pull solenoid 50 as a lateral movement device of the slider 6. The cam 9 has four projecting portions 9a to 9d corresponding to the four steps 14, and a flat portion 9e.
Are provided. When the flat portion 9e is brought into contact with the bent portion 6b, the slider 6 is moved by the pair of springs 7 into the forming die 2.
Move outward from. In this state, the push-pull solenoid 50 can be operated to selectively dispose the tip portions 6c and 6d in the gap 2a. Thus, as shown in FIG. 8, a smooth cutout of the key can be formed, and cutting or polishing of an unnecessary portion of the cutout of the key can be omitted.

The above embodiment of the present invention can be modified. The vertical moving device may use a stepping motor instead of the cam. The mold may be a single key or three or more keys. 6 and 7 show an example in which two tip portions 6c and 6d are formed on the linear portion 6a of the slider 6, but three or more tip portions having different cross sections are provided, and a motor instead of the solenoid 50 is used as appropriate. You may select the front-end | tip part of the linear part 6a.

This embodiment has the following features. (1) The production process can be shortened by omitting the cutting process, the polishing process, and the post-treatment. (2) Keys can be manufactured with high precision and at low cost. (3) High density and high strength keys can be obtained by sintering. (4) Since metal powder is used, keys of various metal compositions including titanium can be manufactured. (5) Since a key having a complicated shape including a three-dimensional structure can be manufactured in one process, it is possible to cope with a key design according to needs. (6) Due to isotropic shrinkage during sintering, the transferability of the mold surface is excellent. (7) Automation of key production becomes easy.

[0026]

As described above, according to the present invention, it is possible to integrally and mass-produce a key including a key mountain shape by a precision casting method.

[Brief description of the drawings]

FIG. 1 is a sectional view of a key manufacturing apparatus according to the present invention.

FIG. 2 is a partial sectional view showing a different section of the key manufacturing apparatus shown in FIG. 1;

FIG. 3 is a front view of a fixed type.

FIG. 4 is a plan view of a molding die.

FIG. 5 is an enlarged sectional view of the key manufacturing apparatus shown in FIG. 1;

FIG. 6 is a sectional view showing another embodiment of the key manufacturing apparatus according to the present invention.

7 is a partial perspective view of a slider used in the key manufacturing apparatus shown in FIG.

FIG. 8 is a partial sectional view of the key manufacturing apparatus shown in FIG. 6;

[Explanation of symbols]

1. Key manufacturing equipment, 2. Mold, 3. Fixed mold, 4. Movable mold, 5. Cavity, 6. Slider, 6a Linear part, 6b Bend part, 7.
・ Spring, 8 ・ ・ Gate, 9 ・ Cam, 9a
... 9d ... projecting part, 9e ... flat part, 10 ... through hole, 11 ... groove part, 20 ... motor, 30 ... rack, 31 ... pinion, 31 ... motor,

Claims (12)

[Claims] An injection molding machine is provided with a molding die having a fixed die and a movable die disposed opposite to the fixed die, and a mixture of the metal powder and the resin is filled in a cavity formed in the molding die. In a metal powder injection molding method in which a molded product is injected in a molten state and a molded product is removed from a cavity after curing of a resin, each of a plurality of sliders is individually moved within a gap of the molding die with respect to a cavity of the molding die. Determining the shape of the notch of the power key, injecting a mixture of metal powder and resin into the cavity in a molten state of the resin by an injection machine of the injection molding machine, and removing the molded product from the cavity after the resin is cured. A method for manufacturing a key, comprising: a step of taking out the key; and a step of heating and sintering the key taken out of the cavity. 2. The method according to claim 1, further comprising the step of removing an unnecessary portion of the molded product taken out of the cavity. 3. The method of manufacturing a key according to claim 1, further comprising a step of removing a resin that imparts fluidity during molding from the key taken out of the cavity. 4. Each of the sliders is moved in a lateral direction, and one of a plurality of tip portions provided at an end portion of the slider is disposed in a gap formed between a fixed die and a movable die, and is placed in a molding die. 4. The method according to claim 1, further comprising the step of individually moving each of the plurality of sliders within the gap of the mold with respect to the cavity formed in the step (a), and determining the shape of the cutout of the key to be manufactured. 2. The method for manufacturing a key according to claim 1. 5. An injection molding machine is provided with a molding die having a fixed die and a movable die disposed opposite to the fixed die, and a mixture of the metal powder and the resin is melted in a cavity of the molding die. In a metal powder injection molding method of injecting and removing a molded product from a cavity after curing of a resin, each of a plurality of sliders is individually moved within a gap of the molding die with respect to a cavity formed in the molding die to manufacture. Determining the shape of the notch of the power key, injecting a mixture of metal powder and resin into the cavity in a molten state of the resin by an injection machine of the injection molding machine, and removing the molded product from the cavity after the resin is cured. Removing the key. 6. The method according to claim 5, further comprising the step of removing an unnecessary portion of the molded product taken out of the cavity. 7. The method of manufacturing a key according to claim 5, further comprising a step of removing a resin that imparts fluidity during molding from the key taken out of the cavity. 8. Each of the sliders is moved in a lateral direction, and one of a plurality of tips provided at an end of the slider is disposed in a gap formed between a fixed die and a movable die, and is placed in a molding die. 8. The method according to claim 5, further comprising the step of individually moving each of the plurality of sliders within the gap of the mold with respect to the cavity formed in the step (a), and determining the shape of the cutout of the key to be manufactured. 2. The method for manufacturing a key according to claim 1. 9. An injection molding machine is provided with a molding die having a fixed die and a movable die disposed opposite to the fixed die, and a mixture of the metal powder and the resin is melted in the cavity of the molding die. In a metal powder injection molding apparatus for injecting and removing a molded product from a cavity after curing of a resin, a plurality of molds are arranged at positions corresponding to cutouts of a key within a gap of the mold with respect to a cavity formed in the mold. A slider, and a vertical moving device for individually moving and fixing the slider within a gap of the molding die with respect to a cavity formed in a shape complementary to the shape of the key, and moving each slider to a predetermined position by the vertical moving device. A key metal powder injection molding apparatus characterized in that a mixture of metal powder and resin is injected into a cavity after the movement, and injection molding is performed. 10. A vertical movement device, comprising: a cam for pressing each slider and changing a protrusion amount of the slider with respect to the cavity; a spring for pressing each slider against the cam;
The metal powder injection molding apparatus for a key according to claim 9, further comprising a motor for rotating each cam. 11. The metal powder injection molding apparatus for a key according to claim 9, wherein the plurality of sliders are provided on both sides of the cavity. 12. A slider disposed in a gap of a molding die has a plurality of tips having different cross-sectional shapes, and the slider is laterally moved by a lateral moving device, and one of the plurality of tips of the slider is moved. The metal powder injection molding apparatus for a key according to any one of claims 9 to 11, wherein one of the keys is arranged in a gap formed between the fixed mold and the movable mold.