JPH07256570A - Nail gun and magnet body therefor - Google Patents

Abstract

PURPOSE:To provide a magnet body for a nail gun which is advantageous for suppressing the trouble of the crack, chipping, etc., of a permanent magnet part in the nail striking, etc. CONSTITUTION:On the body 2 of a nail gun 1, a nail receiving part 25, holding hole 24, and a striking body 30 are installed, and a magnet body 4 is fitted with the holding hole 24. The magnet body 4 is constituted of a sintered magnet part 40 and a pramag part 42 which is formed by covering the whole of the sintered magnet part 40. In the state where the sintered magnet part 40 is arranged in the cavity of a shaping mold, the mixed material containing the Nd-Fe-B group rareeath group magnetic powder and the polyamide resin is solidified through the injection molding into the cavity, and the magnet body 4 is constituted.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a magnet for a nail gun and a nail gun used for driving nails such as nails and tacks.

[0002]

2. Description of the Related Art Nail guns for hitting nails such as nails and tacks to hit nails have been used. This nail gun includes a body having a nail receiving portion for receiving nails, a magnet body held by the body, and a striking body that is shocked by pneumatic pressure. When using the nail, magnetically attract the nail supplied from the nail receiving part with a magnet body, and in that state pneumatically actuate the impacting body, thereby striking the nail with the impacting body. I have to.

By the way, the rare earth-based permanent magnet can obtain strong magnetism. Therefore, a rare earth sintered magnet type (Sm-Co type) permanent magnet is generally used as a magnet body for a nail gun. That is, as shown in FIG. 12, the magnet body includes a rare earth sintered magnet system (Sm—Co system) permanent magnet part 100 and a brass ring 1 in which the permanent magnet part 100 is fitted.
02 and. Then, the brass ring 102 is fitted into the holding hole 106 of the body 104 of the nail gun, and the magnet body is held via the adhesive layer 108.

[0004]

However, the permanent magnet portion 100 of the above magnet body is subject to a shock when nailing, so that problems such as cracking or chipping of the permanent magnet portion 100 may occur. In particular, when the permanent magnet part 100 is formed of a sintered magnet whose impact resistance is not always sufficient, problems such as cracking and chipping easily occur.

The present invention has been made in view of the above situation, and an object thereof is to provide a magnet for a nail gun and a nail gun which are advantageous in avoiding problems such as cracking and chipping of the permanent magnet portion during nail driving. And

[0006]

A magnet body for a nail gun according to claim 1 is provided with a permanent magnet portion having a magnetic pole and at least one magnetic pole of the permanent magnet portion, and a nail attracting surface at a position facing the magnetic pole. , And a coating part containing an organic polymer material as a main component.

The magnet body for a nail gun according to a second aspect is characterized in that, in addition to the magnet body for a nail gun according to the first aspect, the coating portion is made of a mixed material or resin containing rare earth magnet powder and resin. It is what The nail gun according to claim 3 includes a body having a nail receiving portion for receiving a nail and a holding hole, a magnet body fitted in the holding hole of the body for magnetically attracting a nail supplied from the nail receiving portion, and a magnet body. It consists of a striking body that strikes the magnetically attracted nail and strikes it into the driven portion. The magnet body covers the permanent magnet portion having a magnetic pole and at least the magnetic pole of the permanent magnet portion, and opposes the magnetic pole. It is characterized in that it is provided with a nail adsorbing surface at a position and is composed of a coating portion containing an organic polymer material as a main component.

The present invention will be further described. A rare earth magnet system, a ferrite magnet system, or a Fe-Cr-Co magnet system can be adopted as the permanent magnet portion forming the magnet body for the nail gun. Rare earth magnet system is generally Nd-Fe-B system, Sm
-Co type can be adopted. The coating portion forming the magnet body for a nail gun covers at least one magnetic pole serving as a magnetic attraction source for nails in the permanent magnet portion. Therefore,
The covering portion may cover the entire surface of the permanent magnet portion, may cover only one magnetic pole of the permanent magnet portion, or may cover both magnetic poles.

The coating portion may be composed only of an organic polymer material, or may be a form in which the organic polymer material contains other powder (for example, magnet powder), a reinforcing agent, a filler or the like. As the organic polymer material, resin or rubber can be adopted, but resin is preferable in consideration of ensuring abrasion resistance. Of these, a resin having hard and relatively hard wear resistance is preferable. As the resin, a thermosetting resin or a thermoplastic resin can be appropriately used. For example, nylon (polyamide), polycarbonate, polyimide, polysulfone, phenol resin, epoxy resin or the like can be used. Furthermore, engineering plastics such as polyacetal (P0M), polyphenylene oxide (PPO), and polybutylene phthalate (PBT), which are advantageous in terms of abrasion resistance, impact resistance, strength, etc., can also be used.

The covering portion can be generally formed by injection molding, compression molding or the like. The thickness of the coating portion is appropriately selected according to the type of nail gun magnet body, and is, for example, 0.2 to 1.0.
It can be about 0.2 to 0.5 mm, especially about mm. A metal coating may be laminated on the nail gun magnet body. When a metal coating is formed on the nail adsorption surface of the coating portion, it is advantageous to ensure the wear resistance of the coating portion. As the metal coating, an electroless plating film, an ion plating film, or the like can be adopted, and as the material of the metal coating, steel-based or nickel-based having a high magnetic susceptibility can be adopted.

[0011]

According to the first and second aspects of the invention, the nail attracting surface of the covering portion attracts the nail by the magnetism of the permanent magnet portion. Since the coating part containing an organic polymer material as a main component is interposed between the nail and the permanent magnet part, the impact transmitted to the permanent magnet part at the time of nail driving is larger than that in the case without the coating part. , Is alleviated by the covering part.

In the second aspect of the present invention, the magnet body for nail gun is made of a mixed material containing rare earth magnet powder and resin, so that the magnetic attraction force is improved. In the third aspect, the nail received by the nail receiving portion of the body is magnetically attracted to the nail attracting surface of the magnet body. In this state, the nail is hit by the hitting body and is hit into the hit part.

[0013]

EXAMPLES Examples of the present invention will be described below. FIG. 1 conceptually shows a main part of the nail gun 1, and FIG. 2 conceptually shows a state in which the collar portion W1 of the nail W is magnetically attracted to the magnet body 4. 3 and 4 show the magnet body 4 in different directions.
The cross section of is shown.

The cast iron body 2 of the nail gun 1 is provided with a hollow portion 20 and a tubular portion 22 having a nail driving opening 21, and a nail receiving portion 25 for receiving a large number of nails W in an aligned state. Is provided. Nail receiving part 25
A large number of nails W such as steel nails and tacks can be received in the. Each nail W received by the nail receiving portion 25 is fed along the guide 28 in the arrow X1 direction by the feeding wire 27 or the like. Further, the hollow portion 20 of the body 2 is equipped with a striking body 30 which is shocked to move in the direction of the arrow Y1 by air pressure. The body 2 is equipped with an air pressure source serving as a hitting source.

On the wall forming the cavity 20 of the body 2,
A circular holding hole 24 is formed so as to open in the hollow portion 20. The magnet body 4 having a cylindrical shape is fitted and held in the holding hole 24. As shown in FIG. 3, an adhesive layer 24c is interposed in the boundary region between the magnet body 4 and the inner peripheral surface 24a of the holding hole 24. The magnet body 4 is composed of a rare earth-based sintered magnet portion 40 as a permanent magnet portion having a quadrangular shape having magnetic poles, and a plastic magnet portion 42 as a coating portion that covers the entire sintered magnet portion 40. There is. The plastic magnet portion 42 engages and adheres to the minute irregularities on the surface of the sintered magnet portion 40. Pla-mag part 4
2 is a first covering the end surface of the sintered magnet portion 40 on one magnetic pole side.
The plastic magnet portion 42a, a second plastic magnet portion 42b that covers the other magnetic pole side end surface of the sintered magnet portion 40, and a third plastic magnet portion 42c that covers the outer peripheral portion of the sintered magnet portion 40 in a ring shape are provided. The thickness of the first plastic magnet part 42a can be selected as appropriate, but is, for example, 0.2 to 1.0 mm, but 0.2 to 1.0 mm.
It can be about 0.5 mm.

As shown in FIG. 3, the first part of the plastic magnet part 42 is
The plastic magnet portion 42a includes a nail attraction surface 42f that faces the magnetic pole (N pole) of the sintered magnet portion 40. Here, a mixed material containing Nd—Fe—B rare earth magnet powder (average particle size: about 50 to 300 μm) and a polyamide resin is used in a state where the sintered magnet portion 40 is arranged in the cavity of the molding die. The plastic magnet part 42 covers the sintered magnet part 40 by injection-molding the mixed material into the cavity of the molding die and solidifying it. The composition ratio of this mixed material is basically 50% by volume of rare earth magnet powder and 50% of polyamide resin, but it is not limited to these values and can be appropriately selected as necessary. As a design value, the magnetic force of the sintered magnet portion 40 is 42 MG0e, and the magnetic force of the plastic magnet portion 42 is 6 MGOe.

In order to hold the magnet body 4 on the body 2 of the nail gun 1, the following method can be adopted. For example, the holding hole 2
The step of applying an adhesive to at least one of the inner peripheral surface 24a of the magnet 4 and the magnet body 4 and the step of fitting the magnet body 4 into the holding hole 24 can be carried out in order. In addition, the holding hole 24 of the body 2
A step of disposing the sintered magnet portion 40 in the holding hole 24 in a state where the adhesive is applied to the inner peripheral surface 24 a of the holding hole 24.
The step of injecting a mixed material containing rare earth magnet powder and resin by injection molding or the like into the space between the inner peripheral surface 24a and the sintered magnet portion 40 to solidify the mixture material can be sequentially performed. In this case, the mold symmetry between the inner peripheral surface 24a and the outer peripheral surface of the plastic magnet portion 42 is improved, which is advantageous in preventing the magnet body 4 from coming off.

In use, the collar portion W1 and the shaft portion W2
A steel nail W composed of and is used. A large number of nails W are held by the nail receiving portion 25 and are sequentially supplied toward the magnet body 4 along the guide 28 along the direction of the arrow X1 by the feeding wire 27 and the like. As shown in FIGS. 2 and 3, the collar portion W1 of the nail N supplied is magnetically attracted to the nail attracting surface 42f of the magnet body 4, and the nail W is suspended in the cavity 20. As described above, in the state where the collar portion W1 of the nail W is magnetically attracted to the nail attracting surface 42f of the magnet body 4, the air pressure supplied from the air pressure source acts on the impacting body 30, and the impacting body 30 shocks the nail W. The collar portion W1 of the nail W is struck in the direction of the arrow Y1, whereby the tip W3 of the shaft portion W2 of the nail W projects from the nail driving opening 21 and is driven into the driven portion A.

As can be understood from FIG. 3 at the time of such driving, the magnetic pole of the sintered magnet portion 40 serving as a magnetic attraction source for magnetically attracting the collar portion W1 of the nail W and the collar portion W1 of the nail W. The 1st plastic magnet part 42a which has resin as a main component interposes between them. Therefore, the impact transmitted to the sintered magnet portion 40 when the nail W is driven is alleviated by the plastic magnet portion 42, particularly the first plastic magnet portion 42a. Therefore, the sintered magnet part 4
It is advantageous for reducing or avoiding the problem of cracking and chipping of 0.

Further, as can be understood from FIG. 3, the holding hole 24
A third plastic magnet portion 42c containing a resin as a main component is interposed between the inner peripheral surface 24a of the above and the sintered magnet portion 40. Also in this sense, it is advantageous for reducing or avoiding the problem of cracking or chipping of the sintered magnet portion 40 when the nail W is driven. Further, since the second plastic magnet portion 42b is also interposed between the body 2 and the sintered magnet portion 40, it is more advantageous for reducing or avoiding the problem of cracking or chipping of the sintered magnet portion 40.

In general, Nd-Fe-B rare earth magnets have the same size and can obtain a larger magnetic attraction force than Sm-Co rare earth magnets and are advantageous in terms of price. It has the disadvantage of easily forming rust. In this respect, in this embodiment, the entire sintered magnet portion 40 is covered with the plastic magnet portion 42 and is liquid-tightly sealed, so that the rust prevention property is secured. Therefore,
Nd, which is advantageous in terms of magnetic attraction but has rust resistance
An advantage that a —Fe—B-based rare earth magnet can be used as the sintered magnet section 40 is obtained. Therefore, the magnetic attraction force per unit cross-sectional area of the magnet body 4 can be increased.

Further, even if the sintered magnet portion 40 is cracked due to an unexpected impact, in the present embodiment, the entire sintered magnet portion 40 is covered with the plastic magnet portion 42. Therefore, the problem that the broken small pieces are separated from the holding hole 24 is avoided, which is advantageous for maintaining the magnetic force of the magnet body 4. Further, the resin, which is the main component of the plastic magnet part 42, has a coefficient of thermal expansion larger than that of the cast iron forming the body 2. Therefore, even when the nail gun 1 is used in a place having a high temperature atmosphere such as the outdoors where direct sunlight is incident in the summer, the occurrence of clearance due to the difference in thermal expansion between the plastic magnet part 42 and the body 2 is avoided. Is advantageous. Therefore, even if the adhesive force of the adhesive layer 24c deteriorates, the effect of suppressing the detachment of the magnet body 4 from the body 2 can be expected.

(Other Examples) FIGS. 5 and 6 show a second embodiment. Similar to the above, the magnet body 4 is composed of a quadrangular sintered magnet portion 40 having magnetic poles, and a plastic magnet portion 42 covering the sintered magnet portion 40. And plastic mug section 4
Reference numeral 2 denotes a first plastic magnet portion 42a which covers one magnetic pole of the sintered magnet portion 40 and has an attracting surface 42f, and the sintered magnet portion 4
The metal coating 42d for covering the other magnetic pole of 0 and the sintered magnet portion 4
And a third plastic magnet portion 42c that covers the outer peripheral portion of 0.

FIG. 7 shows the third embodiment. The plastic magnet portion 42 of the magnet body 4 covers only one end surface of the sintered magnet portion 40 on the magnetic pole side. In this case, the sintered magnet portion 40 having a strong magnetic force occupies a large proportion of the entire volume of the magnet body 4 for nail gun, so that the magnet body 4 for nail gun can be made compact while maintaining a large magnetic attraction force. It is advantageous to achieve

FIG. 8 shows a fourth embodiment. In this magnet body 4, a metal coating 43 is laminated on the end surface of the plastic magnet part 42. The metal coating 43 is formed of, for example, a nickel electroless plating film or an amorphous foil having excellent magnetic properties and high strength. In this example, since the metal coating 43 contacts the outer peripheral portion of the collar W1 of the nail W, it is advantageous for reducing the wear of the plastic magnet portion 42 containing resin as a main component.

FIG. 9 shows a fifth embodiment. The suction surface 42f of the plastic magnet 42 of the magnet body 4 is formed by an arc surface with a curvature that can correspond to an arc of the outer peripheral surface W1 _a of the flange W1 of the nail W. In this example, the positioning of the collar W1 of the nail W in the direction of arrow A is improved by the arc surface. FIG. 10 shows Example 6. Plastic magnet part 42 of this magnet body 4
Has a ring-shaped thin soft layer 42r on the outer periphery thereof. The thin soft layer 42r is advantageous in impact relaxation. The soft layer 42r can be formed of foam, soft resin, rubber or the like.

FIG. 11 shows a seventh embodiment. In this example, with the sintered magnet portion 40 arranged in the holding hole 24 of the nail gun 1, rare earth magnet powder and resin are placed in the space between the inner peripheral surface 24 a of the holding hole 24 and the sintered magnet portion 40. The mixed material containing is injected and solidified by injection molding or the like to form the plastic magnet portion 42. In this example, if the concave or convex engaging portion 24x is formed on the inner peripheral surface 24a of the holding hole 24, the engaged portion 42x is integrally molded with the plastic magnet portion 42, so that the engaging portion 2
The holding hole 24 is formed by the engaging action of the 4x and the engaged portion 42x.
This is advantageous for preventing the magnet body 4 from coming off. Engagement part 24x
For example, a key groove shape, a key protrusion shape, a spline shape, a bottomed hole shape, etc. can be adopted.

In the example shown in FIG. 1, the nail W is magnetically attracted by one magnet body 4, but the invention is not limited to this.
The two magnet bodies 4 may be provided so as to face each other via the hollow portion 20, and the two magnet bodies 4 may be magnetically attracted from both sides of the collar portion W1 of the nail W. In the example shown in FIG. 1, the impact source in the nail gun 1 is a form that uses air pressure, but is not limited to this and may be a form that applies hydraulic pressure such as hydraulic pressure, or by using a hammer, a weight, or the like. A form in which the impacting body is mechanically impacted may be used.

Besides, the present invention is not limited to the embodiments described above and shown in the drawings, but may be appropriately modified and implemented within the scope not departing from the gist.

[0030]

According to the magnet body for a nail gun of claim 1, since the permanent magnet portion is coated with the coating portion containing the organic polymer material as a main component, the impact at the time of nail driving is alleviated, Cracking, chipping, etc. in the permanent magnet portion are reduced or avoided. Therefore, it is suitable for a rare earth-based sintered magnet in which the magnetic force is large but the permanent magnet portion is likely to crack.

According to the magnet body for a nail gun of claim 2,
Since the coating portion is made of the mixed material containing the rare earth magnet powder and the resin, or the resin, the coating portion itself has the magnetic attraction force, which is advantageous for securing the magnetic attraction force of the nail. According to the nail gun of the third aspect, since the permanent magnet portion is covered with the coating portion containing the organic polymer material as a main component, cracking, chipping, etc. during nailing can be reduced or avoided.

[Brief description of drawings]

FIG. 1 is a configuration diagram showing a concept of a main part of a nail gun.

FIG. 2 is a perspective view showing a state in which a collar portion of a nail is attracted by a magnet body.

FIG. 3 is a cross-sectional view showing a state where a collar body of a nail is attracted by a magnet body.

FIG. 4 is a sectional view of the magnet body taken along a direction perpendicular to its axis.

FIG. 5 is a cross-sectional view of a magnet body according to a second embodiment in the axial direction.

FIG. 6 is a sectional view of a magnet body according to a second embodiment taken along a direction perpendicular to an axis thereof.

FIG. 7 is a sectional view of a magnet body according to a third embodiment, taken along the axial direction.

FIG. 8 is a cross-sectional view of a magnet body according to a fourth embodiment, taken along the axial direction.

FIG. 9 is a cross-sectional view showing a state in which the collar portion of the nail is in contact with the plastic magnet portion of the magnet body according to the fifth embodiment.

FIG. 10 is a cross-sectional view of a state where a magnet body according to a sixth embodiment is held by a body.

FIG. 11 is a cross-sectional view of a state in which the magnet body according to the seventh embodiment is held by the body.

FIG. 12 is a cross-sectional view of a state in which a magnet body according to a conventional example is held by a body.

[Explanation of symbols]

In the figure, 1 is a nail gun, 2 is a body, 25 is a nail receiving portion, 30 is a hitting body, 4 is a magnet body for nail gun, 40 is a sintered magnet portion (permanent magnet portion), 42 is a plastic magnet portion (covering portion), 42f is a nail suction surface, W is a nail, and W1 is a collar.

Claims (3)

[Claims] 1. A permanent magnet portion having a magnetic pole, and a coating portion which covers at least one magnetic pole of the permanent magnet portion and has a nail attracting surface at a position facing the magnetic pole, and which has an organic polymer material as a main component. A magnet body for a nail gun, which is composed of and. 2. The magnet body for a nail gun according to claim 1, wherein the coating portion is made of a mixed material or resin containing rare earth magnet powder and resin. 3. A body having a nail receiving portion for receiving a nail and a holding hole, a magnet body fitted in the holding hole of the body for magnetically attracting a nail supplied from the nail receiving portion, and the magnet body. And a striking body for striking the nail magnetically attracted to the striking target portion. The magnet body covers a permanent magnet portion having a magnetic pole and at least one magnetic pole of the permanent magnet portion. A nail gun comprising a nail adsorption surface at a position facing the magnetic pole, and a coating portion containing an organic polymer material as a main component.