JPS5940969Y2 - Pipe cutter with automatic cutting device - Google Patents

Description

[Detailed description of the invention] This invention is related to the improvement of a pipe cutter, and the extrusion amount corresponding to the wall thickness of the pipe-shaped workpiece to be cut and the pressing force suitable for cutting the workpiece are determined in advance. To provide a pipe cutter with an automatic cutting device that can automatically push out a suitable cutter member under the action of a spring member in a prescribed state.

= As is well known, in a typical pipe cutter, the cutter assembly is fixed or permanently installed in front of the spindle of the pipe cutting machine, and the pipe material is cut while being rotated by the chuck of the cutting machine. There are two types: one is a mechanical type, and the other is a manual type, in which the pipe material is fixed and the entire cutter assembly attached to the outside of the pipe is rotated.

Such pipe cutters are used to process pipe materials of a desired length in factories or other facilities, or to cut existing pipes buried underground during plumbing work. However, with almost no exceptions, the known cutter parts, which are assembled into the cutter assembly, are manually pressed against the pipe material, which causes many problems in practical cutting operations. Contains points.

For example, in connection with the varying hardness of pipe materials,
When manually pushing the cutter member forward, it is relatively difficult to apply a pressure suitable for cutting the pipe material, and by pressing the cutter member excessively against the pipe material, the cutter member may This may cause damage not only to one part but also to the pipe material, or if the button is pressed during the entire cutting process, constant pressure (
Preferably, it is not possible to apply a pressure force that gradually decreases as the end of cutting approaches.
In addition to causing uneven wear of the cutter and a reduction in cutting efficiency, it may distort the cut end of the pipe material at the end of cutting, or it may pierce a part of the pipe material, especially when using a bit-shaped cutter. This inconvenience often occurs.

Therefore, when using a conventional pipe cutter, it is necessary to select the appropriate cutter material and to have some level of skill and caution in regards to the operator handling it, which makes it safe. Efficient performance of cutting operations is hindered.

For this reason, a roll cutter is used as a pipe cutter to cut soft metal pipes made of aluminum or vinyl-coated pipes, etc., and the cutter is pressed against the pipe material by the elastic force of a spring such as a coil spring. A push cutter was proposed (Jikko Kosho 38-7799)
Although this method has the advantage of being able to elastically apply a constant pressing force to the roll regardless of the strength of the operator, it has some practical problems.

First, in the above-mentioned pipe cutting machine, the proximal end of the support arm equipped with the roll cutter is pivoted to the body of the cutter assembly, and the through hole in the support arm is inserted above the cutter. The tip of the screw rod for extruding the roll cutter is in a protruding state, and one washer is engaged with the middle part of such a screw rod, and the other washer is engaged with the through hole at the lower part thereof. Since the spring is attached between the support arm and the support arm, the lowering range of the support arm (the range in which the support arm descends by rotating around the pivot point at the proximal end) is considerably large. Where it can be set,
The spring can be expanded and contracted within the movable range of the two washers, and has a wide range in the past, from a pressurized state with virtually no load on the pipe material to a maximum pressure state where the spring is completely compressed. Advantages include not only being able to apply a pressing force of up to 300 mm, but also being able to keep the roll cutter pressed against the pipe material under the preferable elastic action of the spring within a space that is large enough to push through the pipe material. However, this means that the roll cutter cannot be set uniformly for pipe materials of different hardness or diameter, and the operating stroke of the spring varies over a wide range. As a result, it becomes difficult to set a pressure suitable for cutting the pipe.

Moreover, if we focus on the movement of the spring itself, it is free to move downward along the axis of the threaded rod unless the downward movement of the support arm is prevented, and there are no disadvantages such as those described for general pipe cutters. In other words, at the end of cutting, the roll cutter, which has no restriction on the end of its forward stroke, may distort the cut end of the pipe material or completely cut off the peripheral wall of the pipe material. Despite this, inconveniences such as forcing the roll cutter into the interior of the pipe through a portion of the weakened peripheral wall of the pipe material cannot be avoided.

In addition to this, when applying the above pipe cutter,
Even if a strong spring or coil spring is tried to be installed for cutting hard pipes, it is impossible due to the structure where the worker actually has to lift the support arm by hand, or Regarding this, the pipe material cannot be set smoothly in a short time, and furthermore, the contact point (cutting action point) of the roll cutter with the pipe material must be set linearly along the axis of the threaded rod. However, overall, there are some problems that need to be solved during implementation, such as the inability to use a bite-shaped cutter instead of a roll-shaped cutter. The above-mentioned push cutter is noteworthy in that the cutter member is elastically applied to the pipe material.

A good example of a pipe cutter using a spring as described above can be seen in the manual pipe cutting machine that has appeared in recent years (Japanese Patent Publication No. 47546/1983).
As for this cutting machine itself, the movement of the coil spring is virtually unlimited in the radial direction of the pipe material (with the cutter's forward stroke Since the cutting tool is designed to push out the cutter (without regulating the end of the cutter), as mentioned earlier, the last 1 to 2 rotations are necessary when the cutting is nearing completion. Although there is still a thin outer circumferential portion that should be cut off, there is a risk that the bit-shaped cutter will plunge into this, and if the entire culm is not carefully cut, there is a danger that the cutter will be damaged by the pipe material alone. cannot be resolved.

In addition, in this cutting machine, the extrusion operation of the cutter relies on intermittent movement by a so-called ratchet mechanism and its operation handle, so the coil spring is not activated during each extrusion operation with the handle. However, when looking at the entire cutting process, it is necessary to apply the same pressure force to the pipe material via the spring each time a certain amount of cut is made. Therefore, in terms of the amount of work, the amount of work required is comparable to that of a conventional general pipe cutter.

The amount of work in this case is expressed as the product of the operating force required to sufficiently compress the spring and the number of operations at the end of cutting 4. In the example of the pipe cutting machine mentioned above,
Although it is possible to recognize the new idea of pushing the cutter elastically along the radial direction of the pipe material, overall there are significant advantages in terms of work efficiency and safety compared to the conventional pipe cutter. It is difficult to find out.

In addition, a highly practical pipe cutter (see Japanese Utility Model Publication No. 33-6787) has been proposed as a combination of a bit-shaped cutter and a roller-shaped cutter, but this includes the above-mentioned method. Not only does it have a spring like this, but no special ingenuity has been added to incorporate it.

This invention was made with attention to the above-mentioned points, and in order to solve the various problems of those known pipe machines all at once, the extrusion amount corresponds to the wall thickness of the pipe-shaped workpiece to be cut. A pipe cutter with an automatic cutting device that can automatically push out an appropriate cutter member under the action of a spring member that has a predetermined pressing force suitable for cutting the workpiece. is intended to provide.

Another purpose of this invention is to allow the operator to visually check the appropriate depth of cut that corresponds to the thickness of the pipe material to be cut.
An object of the present invention is to provide an automatic cutting device that can be adjusted.

Another object of this invention is to provide an automatic cutting device that can be assembled with a small number of fine points without making major changes to the structure of a conventional general pipe cutter.

Some of the above-mentioned objects of this invention can be achieved by constructing a pipe cutter having the structure as illustrated below.

To explain a specific example with reference to the drawings, in Figs. 1 to 3, 1 is a saddle part for a pipe cutter installed at a fixed position in front of a spindle (not shown) of a pipe cutting machine, and 2 is a cutting part. These arm portions are integrally connected to a pair of pipe-like workpiece holding arm portions 2a, 2b, which are formed so as to be able to hold the pipe-like workpiece X from both sides. A pipe cutter body consisting of a connecting portion 2c, on which a plurality of guide rollers 3 for supporting the workpiece X are rotatably installed on a support shaft 3a at appropriate locations inside the pipe cutter body. It is.

In the illustrated embodiment, two of these guide rollers are attached to the arm portion 2a on the left side in FIG. , the above-mentioned workpiece It is attached to the arm part 2a, and the other part is attached to the connecting part 2c or the second part, for example.
It can also be attached on the arm member 2b of (see Fig. 7).
.

Further, the second arm portion 2b has an extrusion operation ring I having the form of a screw shaft that can move forward and backward along the radial direction of the workpiece X, and an extrusion operation ring I for causing the operation ring to move forward and backward. and a cylindrical member screwed onto the threaded portion 7' in a state in which rotation is suppressed, preferably a convex portion 2 provided on the side of the arm portion 2b.
d and the nut member 8 which is supported so as not to rotate together with the extrusion operation ring 7 through a recess 8a provided in the member itself, and an axis t (this axis is The guide portion 2e inside the connecting portion 2c of the pipe cutter main body moves forward and backward along the direction (passing on the radius line of the workpiece) but does not rotate.
A cutter mounting member 6 having a concave groove 6a engaged with the cutter mounting member 6 is installed.

In this example, such a cutter mounting member is suitable for fitting the rotary connector 10 formed by a C-shaped washer, for example, the inner end of the extrusion operation ring 7, into the inner end of the operation ring 7. the insertion hole 6b and the annular groove 7 provided at the inner end thereof.
The nut member 8 is supported so as not to move in the direction of the axis l, and the push-out operation ring 7 is connected to the push-out operation ring 7. When rotated, the threaded portion 7' of this operating ring engages with the threaded hole 8' of the nut member 8,
As the operation ring 7 moves along the axis, the cutter mounting member 6 can be moved forward and backward in the same direction.

Therefore, in the above configuration, as shown in the figure, the cutter member 5 is rotatable by the rotary shaft 5a with respect to the cutter mounting member 6 so as to face the guide roller 3 on the first arm portion 2a. If the push-out operation ring 1 is rotated, the two guide rollers 3 on the first arm portion 2a side and the roller-shaped cutter member 5 on the cutter mounting member 6 side will be moved. By adjusting the distance (spacing) between the two, it is possible to hold the workpieces It is practically known as it can be seen in commercially available products.

In the figure, 1a indicates a retaining support portion protruding from the upper side of the distal end of the saddle portion 1, and 1b indicates an engagement groove provided on the engagement support portion.
2f is an engagement protrusion provided on the lower side of the second arm portion 2b so as to engage with the engagement groove 1b, and 2g is provided on the side surface of the first arm portion 2a. 7b is the operating knob of the extrusion operation ring 7, 11 is a pivot pin passed through the protrusion 2g, and the pipe cutter main body 1 can be moved to the operating position shown in FIG. 1 by the coaxial pivot pin. The engagement protrusion 2f can be rotated in the direction away from the engagement groove 1b when set to 1 or when not in use.

The automatic cutting device according to this invention has the basic structure of a pipe cutter as described above, and has a pipe-shaped workpiece X in the second arm portion 2b. Push-out operation ring insertion hole 20 that opens along the radial direction
A large-diameter nut member insertion part 21 is provided coaxially with the insertion hole 20 and the insertion part 21, and the extrusion operation ring 7 and the nut member 8 are moved along their axis l. At the same time, a part of the second arm portion 2b is provided with a nut member locking surface 22 extending in a direction perpendicular to the axis t. The member 8 is kept in a locked state so as not to advance any further, and the rear end side of the nut member 8 not only allows the backward movement of the nut member but also has a structure suitable for accommodating the spring member 23 to be applied. The nut member 8 is characterized in that a long hole 24 is provided, and the nut member 8 is biased in the forward direction by the compressed spring member 23 inside the long hole.

Examples illustrated in Figures 1 to 3 (first example)
is a relatively simple implementation of the above-mentioned structural features, and one end of the arm portion 2b (in Fig. 1,
By providing an elongated hole 24 with an inner diameter somewhat larger than that of the spring member 23 between the push-out operation ring insertion hole 20 formed at the right end (right end) and the nut member insertion portion 21 formed at the other end, The nut member locking surface 22 is an end surface formed on the inner end (closer to the workpiece) of the elongated hole.

In this example, as the nut member 8, a substantially cylindrical member having a flange portion 8b for regulating the backward movement at one end can be used (see FIG. 3).
When fitting this into the nut member fitting part 21,
Pass the other end of the side without the stopper 8b through the nut member insertion part 21 and make it protrude into the elongated hole 24, and then attach the horseshoe-shaped retaining ring 13 onto the protruding part with the setscrew 12. By doing so, the mounting state as shown in FIG. 1 can be obtained.

A similar mounting state can be realized even when the nut member 8 and the retaining ring 13, or the end plate 14 which can be applied to the side end of the ring as necessary, are integrally constructed. However, in order to prevent the retaining ring 13 and the end plate 14 from interfering with the installation of the nut member 8, the area surrounded by the dashed line in FIG. It is necessary to take measures such as using a ring type.

After the nut member 8 is installed as described above, the spring member 23 is removed using a suitable known clamping tool.
When the roller-shaped cutter member 5 is used to cut a relatively hard pipe material as in this example, the above t1 is compressed with a pressure of 9 to 500 to 1000. The extrusion operation ring 7 is inserted between the end plate 14 and the outer end surface 24a of the elongated hole 24.
are inserted into their centers from the right side in the figure. Under such circumstances, the inner end surface of the long groove 24 is secured to the nut member 8 by the nut member locking surface 22 described above.
At the same time, it is directly locked through the retaining ring 13 so that it does not advance any further due to the elasticity of the spring member 23, and at the same time, the nut member is connected to the flange portion 8b at the inner end (front end) of the nut member and facing this. The inner surface 2b of the arm portion 2b
' It becomes possible to form a state in which a predetermined gap C is provided between the two.

Therefore, if the assembled push-out operation ring 7 is rotated under such circumstances, it initially supports the nut member 8 unrotatably, and the elasticity of the spring member 23 prevents the nut member from engaging. Since it is pressed onto the stop surface 22, only the operating ring 7 is aligned with their common axis due to the mutual meshing action of the threaded hole 8' of the nut member and the threaded portion 7' on the outer periphery of the operating ring. However, from the time when the cutter member 5 comes into contact with the outer periphery of the workpiece X, the operation ring 7 cannot be moved forward, and instead, the nut member 8 itself At its rear end, the spring member 23 is pushed back while applying an extra pressure (for example, about 50 kg) in addition to the initial pressure (for example, 500 KI) (straight line in the graph in Fig. 9: m reference).

In this case, the retraction width of the nut member 8 naturally corresponds to the width of the above-mentioned gap C, which is the width of the gap C between the flange portion 8b for restricting the retraction movement and the inner end surface 2b' of the arm portion. 1, by adjusting the thickness of the retaining ring 13 and the mounting position of the ring with respect to the outer peripheral surface of the nut member 8, it can be made substantially equal to the wall thickness of the pipe-shaped workpiece X to be cut. This is so that it can be adjusted in advance to a somewhat larger value.

After completing the setting operation for the desired depth of cut, next when rotating the spindle of the cutting machine mentioned above to rotate the workpiece X, the straight line in the graph shown in Fig. The cutting edge portion 5' of the cutter member 5 bites into the outer periphery of the rotating workpiece X due to the elastic force of the spring member 23 acting in the section 'C' on M. As a result, the extrusion operation ring γ can be advanced integrally with the nut member 8, and finally the nut member 8 reaches the size specified by the previous extrusion operation 47 in one setting operation. Move forward by the retreat width (depth of cut),
The intended cutting operation is completed when the nut member stops upon hitting the locking surface 22 of the nut member.

At this point, as is clear from the above description, the pressure applied to the spring 23 is at an initial value (for example, 500
Kg), and at the position where the entire thickness of the workpiece X has been cut, the nut member 8 and the nut member locking surface 22 are engaged to prevent the cutter member 5 from moving further Therefore, as shown in FIG. 10, the cutter member 5 can be prevented from protruding beyond the inner circumferential wall of the workpiece X from the position indicated by the solid line in the figure more than necessary. In addition, during the next cutting operation, the extrusion operation ring 7 is removed via the nut member 8 held in place.
It becomes possible to relatively retreat.

According to the above-described embodiment, the desired cutting operation can be performed by one reciprocating movement of the nut member 8 with the spring member 23 interposed, but the maximum movement range of the nut member and the spring member are limited at this time. The strength or force is constant.

Therefore, in order to be able to use the same type or size of pipe cutter even if the hardness or diameter of the workpiece X varies widely, the second arm part is designed as shown in FIG. The elongated hole 24 formed in the slot 2b and the nut member insertion part 21 are sandwiched between each other, and the extrusion operation ring insertion hole 20 is opened at one inner end of the elongated hole 24 and the nut member fitting part 21, and the extrusion ring insertion hole 20 is coaxially connected to the other outer end with a screw 30. The sleeve 31 for adjusting the spring force and the sleeve 32 for adjusting the retraction width of the nut member that are connected together are screwed together 33, and the latter sleeve 3, which is located on the inside of these sleeves, is shown in the drawing.
2, the extrusion operation frame 7 is inserted with the screw 34 so that it can move forward and backward, and the nut member 8 on the operation ring γ in the nut member insertion part 21 and the former spring force adjustment sleeve 31 are used to generate a spring. A structure in which the member 23 is supported and the inner end 32b of the sleeve 32 for adjusting the retraction width of the nut member protrudes at a predetermined distance from the rear end side of the nut member 8 is also practically effective.

In such a configuration, by screwing in the spring force adjustment sleeve 31, the elastic force of the spring member 23 can be adjusted as represented by the straight line N or O toward the graph in FIG. If you screw in the nut member retraction width adjustment sleeve 32 in the same way,
This should achieve that purpose, since it will be possible to adjust the spacing between the nut member 8 and the inner end 32b of the sleeve.

In addition, in the case of the improved example shown in FIG. 4, the nut member insertion part 2
1 and the elongated hole 24 are provided in a continuous manner, so that the inner end surface of the nut member insertion portion 21 and the nut member locking surface 22 actually coincide with each other.

Also, if we pay attention to the movement of the nut member 8 as described above, especially the movement in the backward direction, a scale 9 is placed at an appropriate position on the second arm portion 2b close to the nut member, for example, on the inner edge 2h. By doing this, it is possible to read the amount of retraction of the nut member 8 (as mentioned above, this corresponds to the amount of cut made by the cutter member) on the scale 9, and when scraping, the amount of cut can be read. The operator can visually measure the size of the pipe when setting it up, so when cutting a vinyl clad pipe, for example, there is no need to cut only the vinyl layer and damage the outer periphery of the pipe body more than necessary. It is useful for setting accurate depth of cut.

The poop cutter illustrated in FIGS. 5 and 6 has basically the same structure as the first embodiment described above, but some of the structures have been changed regarding the method of attaching the nut member 8 and the spring member 23. This shows an example (second example).

In the second embodiment, only the nut member fitting part 21 is formed in the second arm part 2b, and the engaging part piece 15 is integrally formed at the rear end of the nut member. Further, while the cylindrical portion 15a of this engaging piece is held in the guide hole 25, the flange portion 15b at the outer end of the engaging piece is projected onto the outer surface 2b of the arm portion 2b. On the other hand, when mounting the spring member 23, a casing 16 having an inner space as the elongated hole 24 is used, the spring 23 is accommodated in the casing, and the engaging piece 1 is attached to the casing 16.
Since the spring member 23 is compressed between the flange portion 15b of 5 and the inner bottom portion of the casing 16 or the ring-shaped spacer 17 applied to the portion,
When the assembled structure as shown in the figure is completed, the nut member 8 is locked by using the end face located on the front side of the nut member 8, that is, the inner end face of the nut member insertion portion 21 as the above-mentioned nut member locking surface 22. The spring 23 inside the casing 16 presses this in the forward direction so that it can be peeled off.

In FIGS. 5 and 6, reference numeral 17 indicates a fixing bolt for fixing the casing 16 to the outer surface 2b'' of the arm portion. It uses thrust bearings.

Therefore, according to the second embodiment described above, the extrusion operation 14
By rotating 7, the cutter member 5 initially advances itself, and from the time the cutter member 5 comes into contact with the workpiece X, the nut member 8 is moved in the backward direction instead of the operation frame 7. In addition, it becomes possible to press the spring member 23 directly through the engagement piece 15, and it is possible to complete the setting operation of the depth of cut similar to that described in the first embodiment. It becomes possible.

Next, to explain the embodiment (third embodiment) shown in Figs. 1 and 8, the pipe cutter in the figures is 1
It has a structure in which a pair of pipe-shaped workpiece holding arm portions 2at2b can be opened and closed by a connecting pin 40 in the middle.

On the inside of the main body 2 of the pipe cutter having such a structure, one guide roller 3 is installed for one arm portion 2a (on the left side in the figure), and two guide rollers are installed for the other arm portion 2b.
A pair of jaws 2i, 2j protrude across each other so that workpieces X of various diameters can be held by the left and right rollers of the guide rollers 3. A spacing adjustment knob 41 is provided for moving the parts toward or away from each other, but the structure of each part is generally well known, so a detailed explanation will be omitted.

In the figure, reference numeral 50 denotes a cutter mounting member insertion hole 51 provided in the arm portion 2b in order to slidably fit the cutter mounting member 6, which has a substantially cylindrical shape, along the axis t.
52 is a guide pin that is engaged with a concave groove 6a provided on the cutter mounting member 6 from the side of the arm portion 2b, and 52 is a guide pin that is attached to the cutter mounting member 6. A mounting screw 53 and a window hole provided for viewing the movement of the nut member 8 in the arm portion 2b are shown, respectively.

This type of pipe cutter is used in a different manner from the above-mentioned two-sided pipe cutter, in that the entire pipe cutter main body 2 is manually rotated around the workpiece X.

Therefore, in order to be able to perform the desired cutting work without applying a large cutting force like those on the two sides, it is possible to use a bit-shaped cutter member 5 instead of a roller-shaped one. , a relatively weak spring member 23 suitable for compressing this (straight line in the graph in FIG. 9: O
), but its functions and usage effects are exactly the same.

That is, when the extrusion operation ring 1 is rotated by its handle or knob 7b, the cutter attachment member 6 is first advanced together with the operation ring I via the fixed nut member 8, and the pipe-shaped workpiece X is rotated. The cutter member 5 is applied to the outer periphery of the cutter member 5, and then the entire operation 197 is moved in the backward direction together with the nut member 8, and the spring member 23 is compressed by the backward movement of the nut member 8 in the same way as on the second side described above. After setting the desired depth of cut, the workpiece By operating the pipe cutter body 2 so as to rotate around the pipe cutter body 2, the cutter member 5 is gradually advanced by the elastic force of the spring member 23 while cutting the workpiece X,
When the entire thickness is cut, the nut member locking surface 22
This prevents the extrusion operation ring 7 from moving forward together with the nut member 8, thereby preventing the cutter member 5 from penetrating beyond the inner circumferential wall of the workpiece X as shown in FIG.

As described above, this invention provides the spring member with a predetermined extrusion amount corresponding to the wall thickness of the pipe-shaped workpiece to be cut and a pressing force suitable for cutting the workpiece. Since the cutter member can be pushed out through the nut member by the action, the following benefits can be obtained when put into practical use.

(1) A desired depth of cut can be easily set by a single operation of rotating the extrusion operation ring in one direction, which is effective in improving operability and reducing labor.

(2) During the above setting operation, the operator can visually measure the width of movement of the nut member moving in the backward direction to set an accurate depth of cut corresponding to the thickness of the workpiece. can.

(3) Since the forward movement of the nut member is stopped by the nut member locking surface when the cutting operation is completed, the cutter member is not allowed to protrude excessively into the workpiece. , the cut edge will not be distorted or the cutter itself will be damaged.

(4) The spring to which a predetermined pressing force is initially applied is further compressed through the nut member during the above setting operation, and the elastic force when the spring member expands causes the cutter to tighten. Since the member is pushed out, if the external force (compressive force) to be applied to the spring member is initially selected according to the hardness of the workpiece, the appropriate pressing force can be applied without too much or too little. By applying this function, the entire thickness of the workpiece can be cut smoothly and reliably.

(5) It can be incorporated into various known pipe cutters with a relatively small number of parts without making major changes to the structure thereof, and can be implemented at low cost.

[Brief explanation of drawings]

Fig. 1 is a partially sectional side view showing the first embodiment of this invention, Fig. 2 is a sectional view taken along the line 1 in Fig. 1, and Fig. 3 shows the overall structure of the nut member used in the first embodiment. FIG. 4 is a partial sectional view showing a modification of the main part of this invention, FIG. 5 is a partial sectional side view showing a second embodiment of this invention, and FIG. 6 is a partial plan view thereof. FIG. 7 is a partially sectional side view showing the third embodiment of this invention, FIG. 8 is a sectional view along the line ■-■ in FIG. 1, and FIG. 9 is an explanatory diagram showing the principle of the operation mode of this invention. FIG. 10 is a schematic plan view showing the cutting state when a roller-shaped member is used as the cutter member, and FIG. 11 is a schematic plan view showing the cutting state when the cutter member is a bit-shaped member. FIG. 2...Pipe cutter main body, 2a>2b...Arm portion for holding pipe-shaped workpiece, 3...Guide roller 5...Cutter member, 6...Cutter mounting member, 7
... Extrusion operation ring, 8... Nut member, 10...
Rotating connector, 20... Push-out operation ring insertion hole, 21...
・Nut member insertion part, 22... Nut member locking surface, 2
3... Spring member, 24... Long hole, X... Pipe-shaped workpiece, l... Axis line.

Claims (2)

[Scope of utility model registration request] (1) A pair of arm parts 2a+2b for holding pipe-shaped workpieces
A pipe cutter main body 2 is formed, and an appropriate number of guide rollers 3 are disposed inside the pipe cutter main body, and at least one of the guide rollers is connected to one of the first A push-out operating ring 7 consisting of a threaded shaft is attached to the arm portion 2a and attached to the other second arm portion 2b. The cutter mounting member 6 is screwed onto the member 8 and moves forward and backward along the radial direction of the pipe-shaped workpiece X to the inner position of the operation ring 7, but does not rotate.
This cutter mounting member is connected to the inner end of the extrusion operation ring 7 by a suitable rotary connector 10, and the cutter mounting member 6 faces the guide roller 3 on the first arm portion 2a. In the pipe cutter configured to have a cutter member 5 attached thereto, an extrusion operation ring insertion hole 20 that opens in the second arm portion 2b along the radial direction of the pipe-shaped workpiece X;
A large-diameter nut member fitting part 21 is provided coaxially with this insertion hole, and the operating ring 7 and the nut member 8 can be advanced and retreated along their axis l through the insertion hole 20 and the fitting part 21. The axis t is supported by a part of the second arm portion 2b.
A nut member locking surface 22 is set extending in a direction perpendicular to the nut member 8, and the nut member 8 is locked at the locking surface so as not to advance any further. An elongated hole 24 is provided with a length suitable for not only allowing the backward movement of the nut member but also for accepting the spring member 23 to be applied. A pipe cutter with an automatic cutting device characterized in that a nut member 8 is urged in the forward direction. (2) The second arm portion 2 corresponding to the nut member 8
A pipe cutter according to claim 1, characterized in that a scale 9 for visually measuring the movement range of the nut member is provided at a position close to the pipe cutter b. 13) The elongated hole 24 formed in the second arm portion 2b
and a spring force in which the extrusion operation ring insertion hole 20 is opened at one inner end of the nut member insertion portion 21 and coaxially connected to the other outer end with a screw 30. The adjustment sleeve 31 and the nut member retraction width adjustment sleeve 32 are screwed together 33,
The screw 3 is inserted through the center of the sleeve 32 for adjusting the retraction width of the nut member located inside of these sleeves.
4, inserting the extrusion operation ring I so as to be able to move forward and backward, and supporting the spring member 23 by the nut member 8 on the operation frame γ in the nut member insertion portion 21 and the spring force adjustment sleeve 31; Further, the inner end portion 32b of the sleeve 32 for adjusting the retraction width of the nut member 8 is provided at a predetermined interval on the retraction side of the nut member 8 and protrudes. pipe cutter.