JP3224401U - Knife with handle made of synthetic resin - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a knife having a handle made of synthetic resin, which can be manufactured by a simple process even in a small-scale business. A handle 2 made of a synthetic resin is formed in a rod shape having an insertion hole 2a in a state where a foaming agent is mixed with a thermoplastic synthetic resin material, and a core 1a of a knife 1 has a tapered tip. The insertion hole 2a of the handle 2 made of a synthetic resin is formed by an insertion hole having a shape substantially similar to the core 1a of the knife 1, and the connection between the core of the knife and the handle is made by a heated knife. The core 1a is inserted by the molten synthetic resin in the insertion hole and the surface of the core when the core 1a is inserted into the insertion hole 2a of the handle. It was configured to be firmly fixed in the hole 2a. [Selection diagram] Fig. 1

Description

  The present invention relates to a knife having a handle made of synthetic resin, which is very easy to manufacture.

  Conventionally, there is a knife having a handle made of synthetic resin, but the manufacturing method is to insert a blade of the knife and a metal part of a core into a mold and inject a synthetic resin around the core. It has been manufactured by so-called insert molding, in which a metal part of a child and a synthetic resin are integrated.

  Further, as shown in Patent Document 1, a concave portion is formed in a handle portion of a blade of a knife, a screw is connected to the handle portion, and the screw portion is heated together with the screw to form a synthetic resin handle. There has been proposed a technique in which the inside of the hole made of synthetic resin is melted by inserting it into the hole, the melted synthetic resin is caused to flow into the concave portion, and then the temperature is returned to room temperature, thereby joining the knife and the handle.

JP 2000-202176 A

  By the way, the former conventional technology requires a device for insert molding, and is a technology for mass production in a factory, for example. Therefore, the problem is that the device configuration is large and is not suitable for a small-scale factory. is there.

  Further, in the latter conventional technique, as a preliminary preparation, it is necessary to join the handle of the knife and the screw by welding or the like, so there are a plurality of structural processes and component configurations, which are not suitable for small-scale businesses to manufacture. , There is a problem.

  The present invention has been made in view of the above-mentioned conventional problems, and has an object to provide a knife having a synthetic resin handle that can be manufactured by a simple process even in a small-scale business. .

To achieve the above object, the present invention
First, a knife having a synthetic resin handle formed by fitting a core of a knife into an insertion hole of a synthetic resin handle, wherein the synthetic resin handle is made of a thermoplastic synthetic resin material. In the state in which the foaming agent is mixed, the mixture is formed into a rod shape having the insertion hole, the knife and the core are integrally formed, and the core has a linear shape with a tapered tip. The insertion hole of the synthetic resin handle is constituted by an insertion hole having a shape substantially similar to the core of the knife or a cross-sectional area slightly smaller than the core, and The bond between the core and the handle is caused by the close contact between the molten synthetic resin in the insertion hole and the surface of the core by the core of the heated kitchen knife being inserted into the insertion hole of the handle. The core is fixed in the insertion hole by the cured molten synthetic resin. It constituted by knife having what is is made of synthetic resin handle which is.

  With this configuration, a simple operation of heating the core of the knife and inserting it into the insertion hole of the synthetic resin handle can produce a knife having a synthetic resin handle. It is possible to realize a knife having a synthetic resin handle that can be mass-produced without the need for a large-scale device such as the above.

  Secondly, the knife comprises a knife having a synthetic resin handle according to the first aspect, wherein the core is heated at a temperature of 400 ° C to 600 ° C.

  The core of the knife can be easily heated by a burner, etc., and at such a temperature, even if a large-scale device such as an injection molding device does not exist, a small-scale plant or the like is made of synthetic resin. Knives having a handle can be mass-produced.

  Third, the amount of the foaming agent mixed with the synthetic resin is from 0.2% by weight to 0.5% by weight with respect to the entire synthetic resin material. Consists of a knife.

  With this configuration, it is possible to form the synthetic resin pattern without, for example, sink marks by, for example, injection molding.

  Fourth, the raw material of the handle made of the synthetic resin is constituted by the knife having the handle made of the synthetic resin according to any one of the first to third aspects, which is a polypropylene resin.

  By using a polypropylene resin as the thermoplastic resin, a knife having a synthetic resin handle can be manufactured at low cost.

  According to the present invention, it is possible to manufacture a knife having a synthetic resin handle by a simple operation of heating the core of the knife and inserting it into the insertion hole of the synthetic resin handle. It is possible to realize a knife having a synthetic resin handle that can be mass-produced without the need for a large-scale device such as the above.

  The core of the knife can be easily heated by a burner, etc., and even if there is no large-scale equipment such as injection molding equipment, mass production of a knife with a synthetic resin handle in a small or medium-sized factory. Can be.

  The molding of the synthetic resin handle can be performed by, for example, injection molding without causing sink marks or the like.

  By using a polypropylene resin as the thermoplastic resin, a knife having a synthetic resin handle can be manufactured at low cost.

(A) is a partial cross-sectional side view of a knife having a handle made of a synthetic resin according to the present invention, (b) is a side view of only the knife, and (c) is an enlarged cross-sectional view taken along line AA of (b). . It is a perspective view of the handle of the same knife. (A) is a front view of the handle of the same knife, (b) is a side view of the same handle, (c) is a rear view of the same handle, and (d) is a cross-sectional view of the same handle. (A) is a side view of a handle of the same knife, (b) is a side view of the same knife, and (c) is a side view of a knife having a blade of another shape.

  Hereinafter, a knife having a handle made of synthetic resin according to the present invention will be described in detail with reference to the accompanying drawings.

  As shown in FIG. 1, the knife according to the present invention is a knife having a synthetic resin handle constituted by inserting a core 1a of a knife 1 into an insertion hole 2a of a synthetic resin handle 2. is there.

  The handle 2 made of synthetic resin is injection-molded into a rod (see FIG. 2) having the insertion hole 2a in a state where a foaming agent is mixed with a thermoplastic synthetic resin material. The handle 2 is configured such that the cross-sectional area of the rear end portion gradually becomes larger than the cross-sectional area of the front end portion where the insertion hole 2a is opened (so that the cross-sectional area becomes tapered toward the rear end). (See FIG. 2, FIG. 3 (b), (d)), when it is grasped by hand, it is configured not to be easily displaced.

  The thermoplastic synthetic resin raw material is preferably a thermoplastic resin such as a polypropylene resin. Incidentally, an ABS resin can also be used. Further, as the blowing agent, N, N'-dinitrosopentamethylenetetramine, azodicarponamide, etc. can be used in addition to baking soda (sodium hydrogen carbonate). The mixing amount of the blowing agent with respect to the synthetic resin is from 0.2% by weight to 0.5% by weight based on the whole synthetic resin material.

  The tip 1b of the core 1a of the knife 1 has a tapered linear shape. The core 1a of the knife 1 has a linear portion having a certain width narrower than the blade portion 1c of the knife, and the tip 1b is gradually tapered. In the knife 1, the blade portion 1c and the core 1a are integrally formed. The knife 1 can be manufactured by various known manufacturing methods. For example, in the case of handmade, there is a method such as forging and casting from a metal lump, and in the case of machine production, there is a method in which a metal plate is stamped into a knife shape and then the blade 1c is sharpened to produce. The material of the blade portion 1c is a metal such as carbon steel or stainless steel, but may be a material such as ceramic.

  The insertion hole 2a of the handle 2 made of the synthetic resin is constituted by an insertion hole 2a having a shape substantially similar to the core 1a of the knife 1 or a cross-sectional area slightly smaller than the core 1a (FIG. 2).

  Since the cross-sectional shape of the core 1a is a rectangular shape as shown in FIG. 1C, the cross-sectional shape of the insertion hole 2a is also a rectangular shape substantially similar to the rectangular shape of the core 1a. The rectangular area S1 'of the cross section of the insertion hole 2a is slightly smaller than the rectangular area S1 of the cross section of the core 1a (S1 ≧ S1'). For example, the cross-sectional shape of the insertion hole 2a (see FIG. 3A) is about 1 to 2 mm in the horizontal direction and about 1 to 1 mm in the vertical direction compared to the cross-sectional shape of the core (see FIG. 1C). Form 2 mm smaller.

  On the other hand, when viewed in the longitudinal direction of the insertion hole 2a, the inner part of the insertion hole 2a is formed to have a tapered shape in accordance with the tapered shape of the distal end portion 1b of the core 1a, and the depth T1 Is configured to be substantially the same as the substantial length T1 of the core 1a (see FIGS. 1A and 1B).

  As shown in FIGS. 2 and 3, the synthetic resin handle 2 has a substantially long rod shape, but has an octagonal cross section as shown in FIGS. 3 (a) and 3 (c). As described above, the shape gradually becomes thicker toward the rear end, so that it is configured so as not to easily slip when gripped by hand.

  The connection between the core 1a of the knife 1 and the handle 2 is performed by melting the core 1a of the heated knife 1 into the insertion hole 2a of the handle 2 by melting. This is performed by the close contact between the resin and the surface 1a 'of the core 1a. At the time of insertion, the core 1a is inserted into the insertion hole 2a from the tapered distal end portion 1b, so that the core 1a can be inserted smoothly.

  The heating temperature of the core 1a of the knife 1 is 400C to 600C. The heated core 1a is heated until the tip of the core 1a becomes red, and the heated core 1a is inserted into the insertion hole 2a of the handle 2. Then, since the core 1a and the inner wall of the insertion hole 2a come into contact with each other, the synthetic resin in the insertion hole 2a is melted and adheres to the surface 1a '(both sides) of the core 1a.

  Thereafter, when the temperature is returned to room temperature, the synthetic resin is a thermoplastic resin, and thus, when the temperature is returned to room temperature, the synthetic resin is cured in a state in which it is in close contact with the core 1a. That is, the core 1a is firmly fixed in the insertion hole 2a by the cured molten resin.

(Example)
(Handle of knife)
A knife handle 2 shown in FIG. 2 was formed by injection molding using a thermoplastic synthetic resin in which a blowing agent (baking soda) was mixed in a weight of 0.3% by weight based on the total weight of the polypropylene resin. Since the synthetic resin material contained a foaming agent, molding could be performed without causing sink marks.

(Knife)
As shown in FIG. 1B, the knife was made of a metal blade 1c and a core 1a.

(Combination of knife and handle)
Thereafter, the core 1a of the knife 1 was heated by a burner. At this time, since the tip 1b of the core 1a is heated until the tip 1b becomes slightly red, it is considered that the temperature of the tip 1b is heated to about 600 ° C.

  Thereafter, the handle 2 is fixed with a vice or the like, and the heated core 1a of the knife 1 is inserted into the insertion hole 2a of the handle 2. Insertion is performed until the tip 1b of the core 1a reaches the depth of the insertion hole 2a (see FIG. 1A).

  Then, the synthetic resin having a certain thickness in the thickness direction of the inner wall of the insertion hole 2a of the handle 2 is melted by heat and adheres to the surface 1a '(both sides) of the inserted core 1a. Wait until it returns to room temperature.

  When the synthetic resin of the handle 2 returns to room temperature, the thermoplastic synthetic resin on the surface 1a '(both sides) of the core 1a is cured by returning to room temperature and adheres to the surface 1a' (both sides) of the core 1a. It will be in the state of having done.

  Thus, the knife can be easily manufactured simply by heating the core 1a of the knife 1 and inserting it into the insertion hole 2a of the handle 2 made of synthetic resin. Therefore, even a small company in which a large-scale device such as an injection molding device does not exist can be mass-produced relatively easily.

  As described above, according to the present invention, a knife having a synthetic resin handle is manufactured by a simple operation of heating the core 1a of the knife 1 and inserting the core 1a into the insertion hole 2a of the synthetic resin handle 2. Therefore, a knife having a synthetic resin handle that can be mass-produced can be realized without a large-scale device such as an injection molding device.

  The core 1a of the knife 1 can be easily heated by a burner or the like, and even if a large-scale device such as an injection molding device does not exist, a knife having a synthetic resin handle is manufactured in a small factory or the like. can do.

  By containing the foaming agent, the molding of the synthetic resin handle 2 can be performed by, for example, injection molding without causing sink marks or the like.

  By using a polypropylene resin as the thermoplastic resin, a knife having a synthetic resin handle can be manufactured at low cost.

  Note that a concave portion may be provided above or below the core 1a of the knife 1. In this case, when the heated core 1a is inserted into the insertion hole 2a of the handle 2, the molten synthetic resin in the insertion hole 2a is inserted into the concave portion and then hardened, so that the core is more firmly inserted. 1a and handle 2 can be connected and fixed.

  The knife having a synthetic resin handle according to the present invention can be easily manufactured without an injection molding apparatus, and is an excellent knife suitable for mass production.

1 Knife 1a Core 1a 'Surface 1b Tip 2 Handle 2a Insertion hole

Thirdly, the mixing amount with respect to the synthetic resin of the foaming agent, the synthesis for the whole of the resin material, the synthetic resin handle of the first or 2, wherein 0.5 wt% to 0.2 wt% It is constituted by a knife having.

Claims (4)

A knife having a synthetic resin handle constituted by fitting a core of the knife into an insertion hole of a synthetic resin handle,
The synthetic resin handle is formed in a rod shape having the insertion hole in a state where a blowing agent is mixed with a thermoplastic synthetic resin raw material,
The knife and the core are integrally molded, and the core has a tapered straight end.
The insertion hole of the synthetic resin handle is constituted by an insertion hole having a shape substantially similar to the core of the knife or a slightly smaller cross-sectional area than the core,
The connection between the core of the knife and the handle is performed by melting the synthetic resin in the insertion hole and the surface of the core by inserting the core of the heated knife into the insertion hole of the handle. A knife having a handle made of synthetic resin, wherein the core is fixed in the insertion hole by the molten synthetic resin that has been cured by the close contact.   The knife having a handle made of synthetic resin according to claim 1, wherein a heating temperature of the core of the knife is 400C to 600C.   The knife having a handle made of synthetic resin according to claim 1 or 2, wherein a mixing amount of the foaming agent with respect to the synthetic resin is from 0.2% by weight to 0.5% by weight based on the whole synthetic resin material.   The knife having a synthetic resin handle according to any one of claims 1 to 3, wherein a raw material of the synthetic resin handle is a polypropylene resin.

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