JP2502108Y2 - Jig for preparing screw hole - Google Patents

Description

[Detailed description of the device]

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a jig for making a pilot hole for a screw that holds a shaft on a boss of a gear or a pulley.

[0002]

2. Description of the Related Art Conventionally, in order to make a prepared hole for a screw in parts such as gears and pulleys, after marking the surface of a boss with a punch and fixing it with a parallel vise, a tapping drilling machine or the like is used. I had a hole in it.

[0003]

Normally, two or more screw holes are provided at a constant angle with respect to the center. However, in the conventional method of marking a surface and marking with a punch, the positioning of the marking is performed. was difficult. Further, even if the positioning could be performed, it took skill to open all the holes toward the center.

An object of the present invention is to provide a jig that assists in forming a pilot hole of a screw so as to be directed to the center of a shaft and be at an expected angle by simply mounting it on a gear or the like. And

[0005]

In order to achieve the above object, the present invention provides a table having at least a lower surface and an upper surface parallel to each other, and a table provided at a central portion of the table upper surface and having a height equal to or smaller than a thickness of a gear or the like. And a shaft having the same diameter as the shaft on which a gear or the like is mounted, and a plurality of drill guide holes that are provided around the shaft on the top surface of the base and form a constant angle with respect to the center of the shaft. It has a structure characterized by comprising a member having.

The shape of the base may be any size so long as it fits in a parallel vise, but if a prepared hole is formed in a gear or the like at an angle of 90 degrees, a rectangular parallelepiped of isosceles is desirable. A regular hexagonal prism is desirable if a pilot hole is to be made in a gear or the like at an angle of 60 degrees. Similarly, the most compact jig can be made by making the shape of the base into a regular polygonal prism depending on the angle to be expected.

The base, the shaft, and the member are fixed and integrated so as not to separate from each other or cause distortion. Material is SKS
It is desirable to use a hard metal such as S35C or S45C, but it may be hardened by baking after molding with a soft metal such as S35C or S45C. Since the guide hole requires hardness of the material, the hole may be widened and the bush may be driven.

The length of the shaft is not more than the thickness of the gear or the like. If the shaft jumps out of the inner hole of the gear, it will be difficult for the parallel vice to be scissors and a problem will occur.

The shaft is for mounting a gear or the like on the base and has the same diameter as the shaft.

A member having guide holes for a plurality of drills is
One rectangular member may have a plurality of guide holes, but it is preferable to provide a plurality of members having one guide hole because the amount of material is small.

The member is positioned outside the outer diameter of the boss and has a height equal to or smaller than the thickness of the boss of the gear or the like so as not to prevent the gear or the like from being completely mounted on the upper surface of the base of the shaft.

The guide hole of the drill is parallel to the upper surface of the base,
The line that connects the center of the hole and the center of the shaft toward the center of the axis has the expected angle. In this case, the height of the position of the guide hole is constant, but it is possible to use guide holes with different heights in order to handle multiple types of gears with different boss thicknesses with a single jig. is there.

[0013]

With the jig for preparing the prepared hole of the screw configured as described above, first, the gear or the like to be drilled is mounted on the jig,
After fixing with a parallel vise, use a drilling hole to make a hole with a tapping drilling machine. The hole penetrates the gear and reaches the shaft. The burr generated when a hole is formed in the gear or the like is entangled in the hole of the shaft and the guide hole of the member, and the gear or the like is lightly fixed to the jig.

The gear etc. and the jig are removed from the parallel vise, fixed again to the parallel vise so that the next guide hole is on the upper side, and the next hole is made with a tapping drilling machine. When making three or more holes, repeat the above operation.

By removing gears and the like from the jig and removing burrs, a plurality of prepared holes for the screw at desired angles are completed.

Further, the screw holes are completed by tapping with a small radial drilling machine or the like.

[0017]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS The present invention will be described in detail below with reference to embodiments shown in the drawings. FIG. 1 is an explanatory view of the present invention. 1 is a stand,
2 is a shaft, 3 is a drill guide hole, 4 is a member including a guide hole,
The above is the perspective view of the present invention.

Reference numeral 5 is a gear, 6 is a boss of the gear, 7 is an inner hole of the gear, and 8 is a tooth of the gear. The gear 5 is attached to the jig, and the shaft 2 is passed through the inner hole 7. Since the height of the shaft 2 is lower than the length of the inner hole 7, it does not protrude from the inner hole 7. Since the height of the member 4 from the upper surface of the base 1 is equal to the length of the boss 6, the gear teeth 8
The back surface of the boss 6 contacts the top surface of the member 4, and the bottom surface of the boss 6 completely contacts the top surface of the base 1.

The guide hole 3 is located at the center of the height of the member 4 from the upper surface of the base 1. For this reason, if a hole is drilled through the guide hole 3, a pilot hole can be drilled exactly in the center of the boss 6.

There are two guide holes 3, both of which are parallel to the upper surface of the base 1 and toward the center of the shaft 2, and the directions of the two holes are 90 degrees. Therefore,
A 90-degree prepared hole can be easily formed in the boss 6 simply by passing a drill needle through the two guide holes.

Reference numeral 9 is a scratch hole formed when the drill needle penetrates the boss 6, and it is not necessary to provide the scratch hole from the beginning.

[0022]

As is apparent from the above description, the present invention has the following effects. 1. A table having at least a lower surface and an upper surface parallel to each other, a table provided at a central portion of the table upper surface, having a height equal to or smaller than a thickness of a gear or the like, and having a diameter equal to that of a shaft on which the gear or the like is mounted; Since it is composed of a member provided around the shaft and having a plurality of drill guide holes that form a constant angle with respect to the center of the shaft, the gear etc. mounted on the jig are parallel. It can be fixed to the vise, and the pilot hole of the screw can be drilled toward the center of the shaft.

2. Since the guide hole is provided at an expected angle toward the center of the shaft, the pilot hole of the screw can be drilled at a constant angle in the gear or the like by passing the drill of the tapping drilling machine according to the guide hole.

[Brief description of drawings]

FIG. 1 is an explanatory view of the present invention.

[Explanation of symbols]

 1 unit 2 Axis 3 Guide hole 4 Member including guide hole 5 Gear 6 Boss 7 Inner hole 8 Teeth 9 Scratch hole

Claims (1)

(57) [Scope of utility model registration request] 1. A table having at least a lower surface and an upper surface parallel to each other, and a shaft provided at a central portion of the upper surface of the table, having a height equal to or less than a thickness of a gear or the like and having a diameter the same as that of a shaft on which the gear or the like is mounted. And a member provided around the shaft on the table top surface and having a plurality of drill guide holes whose height is equal to or less than the thickness of a gear or the like and has a constant angle with respect to the center of the shaft. A jig for preparing a pilot hole for a screw.