JPH0624809U - Jig for preparing screw hole - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a jig for easily opening prepared holes of a plurality of screws for holding a shaft on a boss of a gear or a pulley at an expected angle. A table having at least a lower surface and an upper surface parallel to each other, a shaft provided in a central portion of the table upper surface, having a height equal to or less 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,
Preparation of a pilot hole for a screw, characterized by comprising a member provided on the upper surface of the base around the shaft and having a plurality of drill guide holes forming a constant angle with respect to the center of the shaft. jig.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a jig for making a prepared hole for a screw that holds a shaft on a boss of a gear or a pulley.

[0002]

[Prior art]

 Conventionally, in order to make a screw pilot hole in parts such as gears and pulleys, the surface of the boss was marked, marked with a punch, fixed with a parallel vise, and then drilled with a tapping drilling machine or the like. .

[0003]

[Problems to be solved by the device]

 Normally, two or more screw holes are formed at a constant angle with respect to the center, but it was difficult to position the mark by the conventional method of marking a surface and marking with a punch. In addition, even if positioning was possible, it required skill to open all the holes toward the center.

The present application aims to provide a jig that assists in forming a pilot hole of a screw so that the screw is attached to a gear or the like toward the center of the shaft and at an angle that is expected. Target

[0005]

[Means for Solving the Problems]

 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 the center of the table upper surface, having a height equal to or less than the thickness of gears and having a diameter such as gears. A shaft having the same diameter as the shaft, and a member having a plurality of drill guide holes provided around the shaft on the upper surface of the base and forming a constant angle with respect to the center of the shaft. It has a structure that

The shape of the base may be any size as 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, depending on the angle you expect, you can make the most compact jig by making the shape of the platform a regular polygonal prism.

The base, the shaft, and the member are fixed and integrated so as not to separate or distort. The material is preferably a hard metal such as SKS, but it may be hardened by molding after molding with a soft metal such as S35C or S45C. Since the guide hole requires the hardness of the material, the bush may be driven by expanding the hole.

The length of the shaft is not more than the thickness of the gear or the like. If the shaft pops out from the inner hole of the gear, it will be difficult to scissor in the parallel vise, causing a problem.

Since the shaft is for mounting a gear or the like on the base, it does not necessarily have to be cylindrical, but it is easy to mount a cylindrical column having the same diameter as the shaft. Also, the gear and the like are not fixed just by mounting them, but they are fixed by a parallel vise, and after the first hole is made, the jig and the gear etc. are lightly fixed by the burr that has occurred. This fixing does not cause the expected angle deviation between the holes, but if you want a firm fixation, you can fix it by providing a protrusion at the gear position.

A member having a plurality of drill guide holes may have a plurality of guide holes in one rectangular member, but it is better to provide a plurality of members having one guide hole. It is desirable to have less.

The member has a height not more than the thickness of the boss of the gear or the like and is positioned outside the outer diameter of the boss so that the gear or the like is not completely attached to the upper surface of the base of the shaft.

The guide hole of the drill is parallel to the upper surface of the base and faces the center of the shaft, and the line connecting the center of the hole and the center of the shaft has an expected angle. In this case, the height of the guide hole is constant, but in order to handle various types of gears with different boss thickness with a single jig, it is possible to use guide holes with different heights. is there.

[0013]

[Action]

 In the jig for preparing a prepared hole for the screw configured as described above, first attach a gear or the like to be drilled to the jig, fix the jig with a parallel vise, and then use the drill's guide hole to tap. Make a hole with a ping drilling machine. The hole penetrates the gear and reaches the shaft. Burrs that occur when a hole is made in a gear or the like are entangled in the shaft hole and the member guide hole, and the gear or the like is lightly fixed to the jig.

The gear and the like and the jig are removed from the parallel vise, fixed again on the parallel vise so that the next guide hole is on the top, and the next hole is opened by a tapping drilling machine. When making three or more holes, repeat the above operation.

By removing the gear and the like from the jig and removing the burr, a plurality of prepared holes of the screw having an expected angle are completed.

Further, the screw hole is completed by making a tap with a small radial drilling machine or the like.

[0017]

【Example】

 Hereinafter, the present invention will be described in detail with reference to embodiments shown in the drawings. FIG. 1 is an explanatory view of the present invention. 1 is a base, 2 is a shaft, 3 is a drill guide hole, 4 is a member including a guide hole, and the above is a 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 back surface of the gear tooth 8 contacts the upper surface of the member 4, and the bottom surface of the boss 6 completely contacts the upper surface of the base 1. To do.

The guide hole 3 is located in the middle of the height of the member 4 from the upper surface of the base 1. Therefore, if a hole is drilled through the guide hole 3, a pilot hole can be drilled just 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 does not need to be provided from the beginning.

[0022]

[Effect of device]

 As is clear 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 less than a thickness of the gear or the like, and having a diameter equal to that of the shaft on which the gear or the like is mounted It is made up of a member that is provided around the shaft and has a plurality of drill guide holes that form a constant angle with respect to the center of the shaft. 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 the expected angle toward the center of the shaft, the pilot hole of the screw can be drilled at a constant angle in the gear etc. 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)

[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 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. And a member provided around the shaft on the top surface of the base and having a plurality of drill guide holes that form a constant angle with respect to the center of the shaft. Hole making jig.