CN215431696U

CN215431696U - Novel handle-connected twist drill

Info

Publication number: CN215431696U
Application number: CN202120973874.0U
Authority: CN
Inventors: 吴宏; 栾健
Original assignee: Shanghai Louxing Tools Co ltd
Current assignee: Shanghai Louxing Tools Co ltd
Priority date: 2021-05-08
Filing date: 2021-05-08
Publication date: 2022-01-07
Anticipated expiration: 2031-05-08

Abstract

The utility model relates to a novel handle-connected twist drill, which comprises a drill rod and a drill handle connected with the tail end of the drill rod, wherein the front part of the drill rod is of a cylindrical structure with a spiral groove cutting edge on the surface, and the rear part of the drill rod is a connecting part connected with the drill handle; the innovation points are as follows: the connecting part is a cylinder, and a plurality of embedding grooves are formed in the outer circumferential surface of the connecting part and extend to the end face of the tail end of the connecting part along the axis direction of the drill rod; a blind hole for connection is formed in the center of the end face of the front end of the drill shank through cold heading, the blind hole is a round hole for accommodating the cylindrical body of the connecting part to be embedded, and a convex rib matched with the embedding groove is arranged on the inner wall of the round hole; and the connecting part of the drill rod is embedded into the blind hole and is fixedly connected with the drill handle through glue. The utility model has the advantages that: the coaxiality is high. The embedded groove is simple in machining process and small in cutting amount, the whole cross section of the drill rod is larger than that of the regular polygon drill rod, manufacturing cost is reduced, and bending strength is improved.

Description

Novel handle-connected twist drill

Technical Field

The utility model relates to a twist drill, in particular to a novel handle-connected twist drill.

Background

Twist drills are tools for drilling round holes in workpieces by rotary cutting relative to a fixed axis, and are known as twist drills because the chip flutes are helical. The twist drill mainly comprises a drill rod with a cylindrical spiral groove cutting edge structure, a drill bit arranged at the front end of the drill rod and a connecting handle connected with the drill rod.

The present twist drill drilling rod mainly has two kinds with the connection handle connected mode:

(1) the end of the drill rod is cylindrical, the center of the end face of the connecting handle is provided with a connecting blind hole which can just accommodate the drill rod in a cylindrical shape, a thread locking hole which is vertical to the axis of the connecting blind hole and is communicated with the blind hole is drilled on the side wall of the connecting handle, the end of the drill rod is embedded into the connecting handle and is connected onto the thread locking hole through a locking screw, and the end of the locking screw supports against the surface of the drill rod in the blind hole to realize the relative fixation of the connecting handle and the drill rod. The structure of the mode is complex, a thread locking hole needs to be additionally drilled and a locking screw needs to be connected, the processing, manufacturing and assembling procedures are complex, the cost is high, and the mode of lateral pressure locking is not beneficial to the coaxiality control of the drill rod and the connecting handle; in addition, need bore the screw locking hole perpendicular to the connecting handle axis on the lateral wall of connecting handle, this screw locking hole can damage the tensile strength of connecting handle, and mechanical properties influences to some extent, and product quality is unstable.

(2) For example, patent publication No. CN 209698105U discloses a shank-connected twist drill, wherein a regular polygon blind hole is drilled on the end face of the shank, and the rear end of the drill rod is processed into a regular polygon which is just embedded into the blind hole. The thread locking hole is eliminated, so that the whole processing procedure of the handle-connecting twist drill is simplified, and the influence of lateral locking on the coaxiality control of the drill handle and the drill rod can be avoided. It also has certain drawbacks: the whole section of the drill rod is circular, but the lower end of the drill rod needs to be processed into a regular polygon, so that the processing is still complex.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a novel handle-connected twist drill which is simple in structure and processing technology and high in coaxiality.

In order to solve the technical problems, the technical scheme of the utility model is as follows: a novel handle-connected twist drill comprises a drill rod and a drill handle connected with the tail end of the drill rod, wherein the front part of the drill rod is of a cylindrical structure with a spiral groove cutting edge on the surface, and the rear part of the drill rod is a connecting part connected with the drill handle; the innovation points are as follows: the connecting part is a cylinder, and a plurality of embedding grooves are formed in the outer circumferential surface of the connecting part and extend to the end face of the tail end of the connecting part along the axis direction of the drill rod; a blind hole for connection is formed in the center of the end face of the front end of the drill shank through cold heading, the blind hole is a round hole for accommodating the cylindrical body of the connecting part to be embedded, and a convex rib matched with the embedding groove is arranged on the inner wall of the round hole; and the connecting part of the drill rod is embedded into the blind hole and is fixedly connected with the drill handle through glue.

Preferably, the embedding groove is sequentially divided into an embedding main groove and an embedding transition groove from the rear end to the front end of the connecting part of the drill rod, the embedding main groove can just accommodate the convex rib to be embedded, and the cross section of the embedding transition groove is gradually reduced from the rear end to the front end of the connecting part.

Preferably, the cross section of the fitting groove is semicircular, and the cross section of the rib is also semicircular.

The utility model has the advantages that: in the utility model, the tail end of the drill rod is directly embedded with the round hole with the convex rib in the drill handle through the embedding groove for positioning, and the coaxiality is high. The embedded groove is simple in machining process and small in cutting amount, the whole cross section of the drill rod is larger than that of the regular polygon drill rod, manufacturing cost is reduced, and bending strength is improved.

The embedded groove structure with the embedded transition groove is adopted, the processing is convenient, the internal stress distribution can be optimized when the torque is borne, and the service life is prolonged.

Drawings

Fig. 1 is a schematic structural view of the novel handle-connected twist drill in the utility model.

Fig. 2 is a schematic view of the structure of the drill rod in the present invention.

Fig. 3 is a schematic view of the structure of the drill shank of the present invention.

Fig. 4 is a sectional view of the structure of the drill shank of the present invention.

Figure 5 is a side view of a drill shank of the present invention.

Detailed Description

As shown in figure 1, the novel handle-connected twist drill comprises a drill rod 1 and a drill handle 2 connected with the tail end of the drill rod 1, wherein the front part of the drill rod 1 is of a cylindrical structure with a spiral groove blade on the surface, and the rear part of the drill rod 1 is a connecting part connected with the drill handle 2.

In the present invention, as shown in fig. 2, the connection portion of the drill rod 1 is a cylindrical body, and a plurality of fitting grooves are formed on the outer circumferential surface of the connection portion, the fitting grooves extending to the end surface of the connection portion in the axial direction of the drill rod.

As shown in fig. 3 to 5, a blind hole for connection is cold-upset in the center of the front end face of the drill shank 2, the blind hole is a circular hole 21 for accommodating the cylindrical body of the connection part, and a convex rib 22 matched with the embedding groove is arranged on the inner wall of the bottom of the circular hole 21; the connecting part of the drill rod 1 is embedded into the blind hole and is fixedly connected with the drill handle 2 through glue. Further, the height of the rib 22 is lower than the depth of the circular hole 21.

In this embodiment, the engaging groove is sequentially divided into an engaging main groove 11 and an engaging transition groove 12 from the rear end to the front end of the drill rod connecting portion, the engaging main groove 11 can just accommodate the rib 22 to be inserted, and the cross section of the engaging transition groove 12 is gradually reduced from the rear end to the front end of the connecting portion. As the preferred scheme, the number of the embedded grooves and the number of the convex ribs are 3, the embedded grooves and the convex ribs are distributed in a shape like a Chinese character 'ji', the cross sections of the embedded grooves are semicircular, and the cross sections of the convex ribs are also semicircular, so that the stress is better when the torque is borne.

Claims

1. A novel handle-connected twist drill comprises a drill rod and a drill handle connected with the tail end of the drill rod, wherein the front part of the drill rod is of a cylindrical structure with a spiral groove cutting edge on the surface, and the rear part of the drill rod is a connecting part connected with the drill handle; the drill rod connecting structure is characterized in that the connecting portion is a cylinder, a plurality of embedding grooves are formed in the outer circumferential surface of the connecting portion, the embedding grooves extend to the end face of the tail end of the connecting portion along the axis direction of a drill rod, a blind hole for connection is formed in the center of the end face of the front end of the drill handle in a cold heading mode, the blind hole is a circular hole capable of containing the connecting portion cylinder to be embedded in, convex ribs matched with the embedding grooves are arranged on the inner wall of the circular hole, and the connecting portion of the drill rod is embedded into the blind hole and connected and fixed with the drill handle through glue.

2. A novel shank-receiving twist drill according to claim 1, characterized in that: the embedded groove is sequentially divided into an embedded main groove and an embedded transition groove from the rear end to the front end of the connecting part of the drill rod, the embedded main groove can just allow the convex rib to be embedded, and the cross section of the embedded transition groove is gradually reduced from the rear end to the front end of the connecting part.

3. A novel shank-receiving twist drill according to claim 1, characterized in that: the cross section of the embedding groove is semicircular, and the cross section of the convex rib is also semicircular.