RU220658U1 - Age drill cutting head - Google Patents

Abstract

The utility model relates to the field of forestry, in particular to hand tools used in forest taxation, forest management and the study of standing wood, assessing the impact of negative factors on diameter growth, for example, damage to stem pests, rots, and eating by ungulates. The cutting head of an aged drill is made with an initial protruding cutting part in the form of a hollow truncated cone, the large diameter of which is equal to the average diameter of the beginning of the conical part of the thread, and the small diameter is equal to the internal diameter of the cylindrical hole of the cutting head, along which the cutting edge is made, and the latter is formed by conjugating the internal cylindrical and outer conical surfaces of a truncated cone. This design of the cutting head makes it possible to reduce the effort required to insert it into the tree, especially at the initial moment, improve the quality of the core and stabilize the cutting process.

Description

The utility model relates to the field of forestry, in particular to hand tools used in forest taxation, forest management and the study of standing wood, assessing the impact of negative factors on diameter growth, for example, damage to stem pests, rots, and eating by ungulates.

A Pressler drill is known, containing a body in the form of a cylindrical tube, at one end of which there is a cutting head in the form of a multi-start conical thread, and at the other - a handle and a probe. When taking a core of wood, the drill must be pressed against the tree and the handle must be rotated. Pressing is required until the cutting head passes the bark and penetrates into the wood, sufficient to ensure the force of tightening the drill into the wood, due to the screw thread on its cutting head [1].

The disadvantage of this device is that at the initial moment of drilling, a lot of force is required both to press the drill to the tree and to rotate the drill. At this moment, as a rule, the core is destroyed, associated with vibrations of the cutting head due to the uneven application of pressing forces.

A drill cutting head is known, in the design of which, on the front conical surface, grooves inclined to the drill axis are made, directed against the rotation of the drill [2].

The disadvantages of the device include: the difficulty of introducing the cutting head into the wood, especially at the initial moment; The recommended peripheral speed of rotation of the cutting part of the drill of up to 5 m/s can be achieved using an additional tool, which ultimately complicates the work process, especially in the field.

A known cutting head for an aged drill includes a cylindrical tube, at the working end of which there is a multi-start conical thread with an initial cylindrical part, pointed at the end and protruding relative to the beginning of the conical thread by an amount equal to the thread pitch, and its outer diameter is equal to the inner diameter of the beginning of the conical part of the thread [3] - prototype.

Making a cutting head with a protruding cylindrical part with its selected parameters allows you to reduce the load at the initial moment of deepening the thread into the tree trunk, stabilize the cutting process and improve the quality of the core.

However, when taking a core from trees with soft resinous wood (spruce, pine), jamming of the drill head is observed due to wood pulp adhering to the cutting cylindrical part of the head, and the structure of the core is disrupted.

The technical result of the proposed device is to reduce the effort when introducing the cutting head into wood and improve the quality of the resulting core. This is achieved by the fact that the initial protruding cutting part is made in the form of a hollow truncated cone, the large diameter of which is equal to the average diameter of the beginning of the conical part of the thread, and the small diameter is equal to the internal diameter of the cylindrical hole of the cutting head, along which the cutting edge is made. The cutting edge is formed by connecting the inner cylindrical and outer conical surfaces of a truncated cone.

Figure 1 schematically shows the cutting head of an age drill in section A-A. The cutting head includes a cylindrical tube 1, at one end of which there is a multi-start screw conical thread 2, and in front of it a protruding cutting part 3, made in the form of a hollow truncated cone and protruding relative to the beginning of the conical thread 2 by an amount L equal to the thread pitch S, i.e. e. L=S, like the prototype. The large diameter Db.k of a truncated cone is equal to the average diameter of the beginning of the conical part of the thread Dsr.r, i.e. Db.k=Dsr.r, and the small diameter Dm.k is equal to the internal diameter of the cylindrical hole of the cutting head Dvn.ts, along which the cutting edge 4 is made.

The mating of the inner cylindrical surface with the outer conical surface of the truncated cone forms the cutting edge 4.

The working process of the cutting head is as follows.

A tree for core sampling is selected, a coring point is marked on it, to which the cutting head of the drill is attached. By sharply pressing or hitting the opposite end of the cylindrical tube 1, the cutting part 3, made in the form of a hollow truncated cone, is easily inserted by the cutting edge 4 into the bark part of the tree until it touches the beginning of the conical thread. Next, under the action of pressing force and simultaneous rotation of the cylindrical tube 1, the conical thread is screwed into the trunk of the tree under study.

Making the cutting head of an aged drill with the proposed protruding cutting part in the form of a hollow truncated cone with its selected parameters allows us to eliminate the disadvantages of the prototype, namely, to eliminate sticking of the wood pulp when taking a core from trees with soft resinous wood of the cutting part, and therefore jamming; the penetration force is reduced and the quality of the core is improved.

The set of features of the proposed technical solution is novel and has a positive effect. No materials denying novelty were found.

As evidence, an aged auger with the proposed cutting head was manufactured and tested. The research results showed its performance, reliability and quality of the obtained cores.

Information sources

1. Anuchin N.P. Forest taxation: Textbook for universities. - 5th edition, add. - M.: Timber Industry, 1982.

2. Patent for invention RU No. 2158676 “Cutting part of a drill for extracting wood core”, application No. 98120383/13, publ. 11/10/2000.

3. Utility model patent RU No. 214107 “Cutting head of an aged drill”, application No. 2022107646, publ. 10/12/2022. Bull. No. 29 - prototype.

Claims (2)

1. The cutting head of an aged drill, including a cylindrical tube, at the working end of which there is a multi-start conical thread with an initial cylindrical part, pointed at the end and protruding relative to the beginning of the conical thread by an amount equal to the thread pitch, and its outer diameter is equal to the internal diameter of the beginning of the conical part thread, characterized in that the initial protruding cutting part is made in the form of a hollow truncated cone, the large diameter of which is equal to the average diameter of the beginning of the conical part of the thread, and the small diameter is equal to the internal diameter of the cylindrical hole of the cutting head, along which the cutting edge is made. 2. The cutting head of an age drill according to claim 1, characterized in that the cutting edge is formed by connecting the inner cylindrical and outer conical surfaces of a truncated cone.

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