JP3001589U - Head cutter for propulsion - Google Patents

Abstract

(57) [Summary] (Corrected) [Purpose] Preventing damage to the auger screw and damage to the buried pipe by laterally removing stones of a certain size or larger. [Structure] A taper portion 29 is provided at the front end of a cutter shaft 27 attached to the front end of an auger screw shaft 23, and a spiral ridge 31 is formed on the surface of the taper portion. It has a pitch corresponding to the dimensions, and the cutter shaft has a cutter casing 3 behind the spiral ridge.
5 is fixed, and the front edge of the cutter casing is parallel to the rearmost portion 31 'of the spiral ridge and the distance between the front and the rearmost portion is substantially equal to the pitch of the spiral ridge. Head cutter.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a propulsion head cutter in a propulsion device in which a vinyl chloride pipe or other pipe is buried in the ground without cutting the ground surface.

[0002]

[Prior art]

 In the conventional propulsion device, as shown in FIGS. 2 and 3, a head cutter 5 for propulsion is attached to the front end of the shaft 3 of the auger screw 1. That is, the cutter shaft 9 is connected to the front end of the shaft 3 of the auger screw 1 (referred to as the left end in FIG. 2) through the connecting means 7, and the head cutter 5 is attached to the front end of the cutter shaft 9. The head cutter 5 has a large number of chips (blades) 11 at its front end. Reference numeral 12 is a buried pipe such as a vinyl chloride pipe, and reference numeral 13 is a casing of the head cutter 5. The head cutter 5 in such a conventional propulsion device excavates earth and sand, and the earth and sand excavated by the head cutter 5 is carried out to the starting vertical shaft side by the auger screw 1. Therefore, the head cutter 5 has various shapes, but each has a large opening 15 for guiding the earth and sand excavated by the head cutter 5 to the auger screw 1.

[0003]

[Problems to be solved by the device]

 Since the conventional head cutter 5 has the large opening 15 for guiding the excavated earth and sand to the auger screw 1 as described above, the large stone 17 in the soil passes through the opening 15. It is often the case that the auger screw 1 gets caught up. When large stones are taken in in this way, the auger screw 1 may be damaged, and the buried pipe 12 may also be damaged. The present invention has been made in order to solve such a problem.

[0004]

Means for Solving the Problems In order to solve the above problems, the present invention provides a head cutter for propulsion in which the intake of large stones is restricted. That is, the present invention provides a taper portion at the front end of the cutter shaft attached to the front end of the shaft of the auger screw (referred to as the left end in FIG. 1), and forming a spiral ridge on the surface of the taper portion. The ridge has a pitch corresponding to the size of the largest stone that can be taken in, and the cutter shaft is fixed to the rear of the spiral ridge (to the right in Fig. 1) on the cutter shaft. A head cutter for propulsion, characterized in that the front edge of the casing is parallel to the rear end of the spiral ridge and the distance between the front end and the rear end is substantially equal to the pitch of the spiral ridge. is there. (Claim 1)

It is desirable that the pitch of the spiral ridges is 1/3 or less of the inner diameter of the cutter casing. (Claim 2)

[0006]

[Action]

 [Propulsion head cutter according to claim 1] In the propulsion head cutter according to claim 1, the spiral protrusion provided on the cutter shaft and the cutter casing fixed to the cutter shaft rotate together with the auger screw. The spiral ridge of the cutter shaft is cut into the sand and excavated. At this time, stones smaller than the pitch of the spiral ridges are taken into the valley bottom between the spiral ridges along with the soil, sent to the auger screw, and carried out to the starting shaft side by the auger screw. On the other hand, stones larger than the pitch of the spiral ridges are excluded laterally without being trapped between the spiral ridges. Moreover, the front edge of the cutter casing is parallel to the rearmost part of the spiral ridge, and the interval with the rearmost part is almost equal to the pitch of the spiral ridge. It also does not get into the cutter casing through the gap between the last part of the ridge and the front edge of the cutter casing. In this way, stones larger than the pitch of the spiral ridges are prevented from being taken in, so that the auger clew is not damaged or the buried pipe is not damaged.

[Propulsion Head Cutter of Claim 2] In the propulsion head cutter of claim 2, the pitch of the spiral projections is 1/3 or less of the inner diameter of the cutter casing. Therefore, the size of the stone taken in by the head cutter is less than 1/3 of the inner diameter of the cutter casing. If the size of the stone taken in is less than 1/3 of the inner diameter of the cutter casing, damage to the auger screw or damage to the buried pipe due to the stone taken in can be more completely prevented.

[0008]

【Example】

 Next, an embodiment of the present invention will be described with reference to the accompanying drawings. Reference numeral 21 is an auger screw of the propulsion device in the present invention, and 23 is a shaft of the August screw 21. A cutter shaft 27 is connected to the front end of the shaft 23 of the auger screw 21 via a connecting means 25. A taper portion 29 is provided at the front end of the cutter shaft 27, and a spiral ridge 31 is formed on the surface of the taper portion 29. The spiral ridges 31 have a pitch a corresponding to the size of the largest stone that can be incorporated. Further, a cutter casing 35 is fixed to the cutter shaft 27 at the rear of the spiral projection 31 via a support member 33. The front edge 37 of the cutter casing 35 is parallel to the rearmost portion 31 'of the spiral ridge 31 and the distance a'from the rearmost portion 31' is substantially equal to the pitch a of the spiral ridge 31. Further, chips (blades) 39 are attached to the spiral ridge 31 and the front edge 37 of the cutter casing 35, respectively. Reference numeral 41 is a buried pipe, and reference numeral 42 is a large stone that is excluded laterally. In the present invention, a two-step system may be adopted in which the lead tube 43 is previously propelled, the lead tube 43 is connected to the tip of the cutter shaft 27, and this is used as a guide tube. It is also possible to adopt a one-step method that does not use a simple lead tube 43. The propulsion head cutter according to the present invention is particularly effective for the gravel layer, the soft rock layer, the cobblestone layer, and the like.

The pitch a of the spiral ridges 31 is preferably 1/3 or less of the inner diameter b of the cutter casing 35. That is, a ≦ b / 3.

[0010]

[Effect of device]

 As explained above, the head cutter for propulsion according to claim 1 eliminates stones of a certain size or more laterally and prevents such stones from being caught in the auger screw. Will not be damaged or the buried pipe will not be damaged.

Particularly, in the head cutter for propulsion according to the second aspect, since the size of the taken-in stone is 1/3 or less of the inner diameter of the cutter casing, the taken-in stone damages the auger screw or the buried pipe. Damage to the is more completely prevented.

[Brief description of drawings]

FIG. 1 is a sectional view showing an example of a propulsion head cutter according to the present invention.

FIG. 2 is a cross-sectional view showing an example of a conventional propulsion head cutter.

FIG. 3 is a front view of a conventional propulsion head cutter.

[Explanation of symbols]

 1 Auger Screw 3 Shaft 5 Head Cutter 7 Connecting Means 9 Cutter Shaft 11 Tip 12 Buried Pipe 13 Casing 15 Opening 17 Large Stone 21 Auger Screw 23 Shaft 25 Connecting Means 27 Cutter Shaft 29 Taper Part 31 Spiral Ridge 31 'Last Part 33 Support member 35 Cutter casing 37 Front edge 39 Tip 41 Buried pipe 42 Large stone 43 Reed pipe

Claims (2)

[Scope of utility model registration request] 1. A taper portion is provided at a front end of a cutter shaft attached to a front end of an auger screw shaft, and a spiral ridge is formed on a surface of the taper portion. It has a pitch corresponding to the dimensions, and the cutter casing is fixed to the rear of the spiral ridge on the cutter shaft,
A propulsion head cutter, wherein a front edge of the cutter casing is parallel to a rear end of the spiral ridge and a distance between the front end and the rear end is substantially equal to a pitch of the spiral ridge. 2. A cutter shaft attached to a front end of an auger screw shaft is provided with a taper portion at a front end thereof, and a spiral projection is formed on a surface of the taper portion, and the cutter shaft is provided with a cutter behind the spiral projection. The casing is fixed, the spiral ridge has a pitch of 1/3 or less of the inner diameter of the cutter casing, the front edge of the cutter casing is parallel to the rear end of the spiral ridge, and the space between the rear end and the spiral ridge is spiral protrusion. A head cutter for propulsion, which is characterized in that the pitch is substantially equal to the pitch.