Double-end cutting spiral fluted tap

Abstract

The utility model discloses a double-end cutting spiral fluted tap which is characterized in that a first tool bit and a second tool bit which are of an intermittent arrangement structure are arranged at the front end of a tool handle, and the second tool bit carries out secondary cutting in a blind hole along with the first tool bit so as to increase the degree of finish of threads in the blind hole. On one hand, a pair of tool bits with the same structure and opposite blade grooves is arranged at the front end of the tool handle, secondary cutting is carried out on tapping threads, and therefore the smoothness of the threads is improved, and on the other hand, after the front-end tool bit is abraded and fails, the front-end tool bit can be cut off, and the rear-end tool bit can be independently used for tapping machining.

Description

TECHNICAL FIELD

[0001] The utility model relates to the field of spiral flute tap, especially in kind of double -end cutting spiral flute tap. BACKGROUND

[0002] The conventional spiral flute tap usually only has one cutting tool bit, and only one cutting is implemented during tapping, and the surface finish of the processed thread is poor. SUMMARY

[0003] In order to overcome the above-mentioned defects of prior art, the utility model discloses a double -end cutting spiral flute tap, to reach the purpose that improves the surface finish of thread.

[0004] In order to realize the above-mentioned purpose, the utility model adopts the technical scheme of:

[0005] A double -end cutting spiral flute tap, first tool bit and second tool bit of intermittent arrangement structure are arranged at the front end of the tool handle, the second tool bit follows the first tool bit and implements secondary cutting in the blind hole to increase the thread finish in the blind hole.

[0006] In one preferred embodiment of the utility model, the second tool bit is head-to-tail adjacent with the first tool bit, and a gap is arranged between the first tool bit and the second tool bit, the gap separates the first tool bit and the second tool bit to constitute the intermittent arrangement structure.

[0007] In one preferred embodiment of the utility model, the cutting structure of the first tool bit and the second tool bit is same.

[0008] In one preferred embodiment of the utility model, the front end of the first tool bit is provided with the first guide cone, the axial length range of the first guide cone is 1 to 1.4mm, and the lead angle is 22 °.

[0009] In one preferred embodiment of the utility model, it further includes a plurality of first row cutting grooves and first cutting edges alternately arranged, the first row cutting grooves and the first cutting edges spiral extension around the shaft.

[0010] In one preferred embodiment of the utility model, the second tool bit is provided with the second row cutting groove and the second cutting edge, the second row cutting groove is butt jointed with the first row cutting groove, and the second cutting edge is butt jointed with the first cutting edge.

[0011] The utility model has the advantages of:

[0012] The utility model provides a kind of double-end cutting helical groove tap, first aspect is set to a pair of structure same blade groove opposite tool bit in shank front end, realize to thread tapping screw thread implements secondary cutting, to improve the finish of thread, second aspect is before end tool bit wear failure, it can also be cut off and used separately rear end tool bit for tapping machining. BRIEF DESCRIPTION OF DRAWINGS

[0013] In order to more clearly illustrate the technical scheme in the embodiments of the present utility model or prior art, the following will briefly introduce the drawings needed to be used in the embodiment or prior art description.

[0014] Figure 1 It is the side view schematic diagram of the utility model.

[0015] Figure 2 It is the radial section schematic diagram of first tool bit. DETAILED DESCRIPTION

[0016] In the description of the present utility model, it needs to be explained that the orientation or position relationship indicated by terms "upper", "lower", "left", "right", "inner", "outer" and the like is based on the orientation or position relationship shown in the drawings, and the above description is simplified for the convenience of describing the present utility model, and is not indicative or suggestive of the device or element indicated must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present utility model.

[0017] The singular forms "a", "said", and "the" used in the specification are intended to include plural forms unless the context clearly indicates otherwise. The terms "comprise", "include" and "contain" used in the specification mean the presence of the stated feature, but do not exclude the presence of one or more other features. The term "and / or" used in the specification includes any and all combinations of one or more of the related listed items.

[0018] In the specification, when one element is said to be "on", "fixed" to another element, "connected" to another element, "joined" to another element, etc., the element can be directly on, fixed to, connected to, joined to, or in contact with another element, or there can be intervening elements. In the specification, when one feature is arranged "adjacent" to another feature, it can mean that one feature has a portion overlapping with the adjacent feature or a portion above or below the adjacent feature.

[0019] It can be understood that although the terms "first", "second" and the like can be used herein to describe different elements, these elements should not be limited by these terms. These terms are only used to distinguish one element from another. Therefore, the first element can be called the second element without departing from the teachings of the present application.

[0020] The exemplary embodiments of the present application will be described below with reference to the accompanying drawings. It should be understood, however, that the present application can be presented in many different forms and is not limited to the embodiments described below. It should also be understood that the embodiments disclosed herein can be combined in various ways to provide many additional embodiments. In all the drawings, the same reference numerals indicate the same or functionally similar elements.

[0021] Figure 1 And Figure 2 A double-head cutting spiral flute tap is shown, the front end of the tap shank 30 is coaxially provided with a first tap head 10 and a second tap head 20 around the tap axis 1. The first tap head 10 and the second tap head 20 are arranged in a discontinuous arrangement, i.e. the first tap head 10 and the second tap head 20 are arranged end-to-end with a gap 2 therebetween to separate the two tap heads. This allows the tap to achieve two cuts in one tapping when tapping a blind hole.

[0022] The cutting edges and the relief grooves of the first tap head 10 and the second tap head 20 are the same. The front end of the first tap head 10 is provided with a first pilot cone 11 for guiding the tap into the blind hole, the first pilot cone 11 is preferably provided with an axial length of 1 to 1.4 mm and a pilot angle of 22°. The first tap head 10 is also provided with a first helically extending cutting edge 12 and a first relief groove 13, the number of the first cutting edge 12 and the first relief groove 13 is four and they are arranged alternately. The second tap head 20 also has a second pilot cone 21, a second cutting edge 22 and a second relief groove 23, the second cutting edge 22 and the second relief groove 23 correspond to the first cutting edge 12 and the first relief groove 13 and are connected thereto in sequence. This structure allows the second tap head 20 to perform a second cutting along the thread path cut by the first tap head 10 when the first tap head 10 is inserted into the blind hole, thereby improving the smoothness of the thread. At the same time, the discontinuous arrangement of the double tap head structure also allows the first tap head 10 to be cut off from the gap 2 when it is worn out, and the second tap head 20 can be used directly for tapping.

Claims

1. A double-ended spiral groove tap, characterized in that: A first cutter head and a second cutter head in an intermittent arrangement structure are provided at the front end of the tool handle. The second cutter head follows the first cutter head to perform secondary cutting in the blind hole to increase the thread finish in the blind hole.

2. A double-ended spiral groove tap according to claim 1, characterized in that: The second cutter head is adjacent to the first cutter head at the end, and a gap is provided between the first cutter head and the second cutter head. The gap separates the first cutter head from the second cutter head to form the intermittent arrangement structure.

3. A double-ended spiral groove tap according to claim 2, characterized in that: The first cutting head and the second cutting head have the same cutting structure.

4. A double-ended spiral groove tap according to claim 3, characterized in that: A first guide cone is provided at the front end of the first tool head. The axial length of the first guide cone ranges from 1 to 1.4 mm, and the lead-in angle is 22°.

5. A double-ended spiral groove tap as claimed in claim 3, characterized in that: It also includes a plurality of first rows of cutting grooves and first cutting edges that are alternately arranged, wherein the first rows of cutting grooves and the first cutting edges extend spirally around the axis.

6. A double-ended spiral groove tap according to claim 5, characterized in that: The second cutter head is provided with a second row of cutting grooves and a second cutting edge. The second row of cutting grooves is connected to the first row of cutting grooves, and the second cutting edge is connected to the first cutting edge.

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