JPH0152091B2 - - Google Patents

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a pipe bending device for bending a pipe at a predetermined curvature, and in particular, a motor rotates, for example, a semicircular rotating former, and this rotation bends the outer circumference of the rotating former. This invention relates to a pipe bending device that wraps and bends a pipe.

<Conventional technology and problems to be solved> As this type of pipe bending device,
There is one described in Publication No. 161442. This involves holding the end of the pipe on a rotating arc-shaped disk, pressing the pipe against the rotating arc-shaped disk using two guide rollers, and wrapping the pipe around the outer circumference of the rotating arc-shaped disk by rotating the rotating arc-shaped disk. It is something that bends.

"Akira Hashimoto: Press Bending Process (10th Edition) Published: Nikkan Kogyo Shimbun, March 30, 1970"
Pages 156 to 157 disclose a hole-shaped roll bending device in which three rolls form a hole corresponding to the cross section of the pipe, and the three rolls bend the pipe. A straining roll bending device for winding a pipe using straining rolls is also disclosed.

However, while these devices are suitable for bending relatively thick-walled pipes to large radii, they are not suitable for bending thin-walled pipes, and may cause excessive compression of the inner part of the bend, resulting in wrinkles or There is a problem with the outer portion being overstretched, where the material becomes thinner and may crack or break.

One method for bending thin-walled pipes is to insert a mandrel (core material) inside the pipe, but the bending equipment that uses this mandrel has the drawbacks of being complicated to handle and expensive.

An object of the present invention is to provide an electric pipe bending device that can quickly and efficiently bend a thin-walled pipe without using a core material such as a mandrel.

<Means for Solving the Problem> In order to solve this problem, an apparatus according to the present invention has a rotating former and a bending die, and the overall components are as follows.

(a) Main body: Supports each component.

(b) Motor: Installed in the main body. It serves as the driving source for the rotating former.

(c) Reducer: Reduces the rotation of the motor to provide an appropriate bending speed.

(d) Rotating former: Has an arc-shaped outer peripheral surface that corresponds to the pipe bending curve. The center portion thereof is fixed to the output shaft of the speed reducer. Further, a holding groove corresponding to the pipo cross section is formed along the outer peripheral surface.

(e) Bending die: Installed in a fixed position with the pipe sandwiched between it and the rotating former. It also has a guide groove that substantially opposes the holding groove of the rotary former, and this guide groove guides the pipe while sliding it in the axial direction during the bending process.

(f) Bending die support mechanism: Positions the bending die at a predetermined position corresponding to the pipe diameter. As this support mechanism, for example, there is a mode in which the bending die is supported rotatably around an axis parallel to the rotation axis of the rotary former, or a mode in which the bending die is inserted in a wedge shape between this support mechanism and the pipe, There is also a mode in which it is held in a narrow pressure state.

<Function/Effect> In such a pipe bending device, when the pipe is wound into the rotating former, it is passed through the bending die while sliding, thereby applying an appropriate tensile stress to the pipe within its elastic range. It is then bent and formed. As a result, even if the pipe is thin, the outside of the bend will not be excessively stretched and become thin, the inside will not be excessively compressed and wrinkled, or the pipe cross section will become flat, making it a good product. Bending can be performed quickly and quickly.

<Example> Hereinafter, an example of the present invention will be described based on the drawings.

First Embodiment FIGS. 1 to 7 show a first embodiment of the present invention. In Fig. 1, 211 is a box-shaped main body;
A motor and a speed reducer (not shown) are built inside. The output shaft of the reducer protrudes from the top surface of the main body 211, and the rotary former 21 is attached to the output shaft.
3 is fixed by a bolt 216 (see FIG. 2) and appropriate rotation prevention means (not shown). It is desirable to have a speed reducer with a fairly large reduction ratio in order to obtain the bending torque. For example, if you use a motor of about 450 W, you can obtain a rotation speed of about 25,000 to 26,000 rpm, and by reducing the speed For example, about 5
A rotational speed of ~7r.pm is given.

The rotary former in this embodiment is a pulley-like member slightly larger than a semicircle with an angle of over 180 degrees, and bends and forms the pipe t by rotating counterclockwise in FIG. This rotation former 213
A semicircular holding groove 214 is formed on the outer peripheral surface of the arc. This holding groove 214 corresponds to the diameter of the pipe t to be bent, and when bending a pipe of a different diameter, the bolt 216 is removed and the rotating former is replaced with a rotating former having a holding groove 214 that matches the pipe diameter. Become.

A bending die 218 is provided at a position facing the rotary former 213. This bending die 218 is obtained by polishing a suitable metal member such as hardened steel, and is formed vertically so that its cross section is approximately rectangular. A guide groove 260 having a substantially semicircular cross section is formed along its longitudinal direction, and the pipe is guided while sliding in this guide groove 260.

This bending die 218 is shown enlarged in FIG. In the figure, the P side is the side that guides the pipe. As is clear from this figure, the guide groove 260
is divided into three parts: the pipe inlet end 218';
It is provided with an inlet side guide part 245 formed on the side of the pipe, an outlet side guide part 246 formed on the side of the pipe outlet end 218'', and a relief part 248 connecting these parts.Inlet side guide part 245 is formed of a part of a cylindrical surface having a groove depth y, and the delivery side guide portion 246 is formed so that the groove bottom gradually approaches the pipe side toward the delivery side end 218''. In other words, the groove depth of the sending-side guide section 246 is x at the tip, but has the same depth y as the feeding-side guide section 245 at the inner end. FIG. 5 shows the inlet guide part 245 and the outlet guide part 243 of this bending die 218 facing each other with their directions reversed by 180 degrees, and shows the difference in groove depth of each. be.

Also, the guide groove 260 of the bending die 218
The opposite side (back) is divided into three parts. First, a parallel portion 240 parallel to the guide groove 260 is formed from the pipe inlet end 218'. On the other hand, on the side of the pipe delivery side end 218'', there is a slope 2 that slopes toward the tip and toward the guide groove 260.
42 are formed, and a curved recess 241 connecting the parallel portion 240 and the inclined portion 242 is further formed. In other words, this bending die 218 has a wedge-shaped distal end portion, and as shown in FIG. The cylindrical support member 22
The above-mentioned curved recess 241 is pressed onto the outer circumferential surface of 4.

In FIG. 7, the cylindrical support member 224 is fixed on the slider 219, and the slider 219
A pair of grooves 23 as guide portions formed in 11
It is held so that it can approach and move away from the rotating former 213 while being guided by the rotating former 213 . A cross section of this portion is shown in FIG. A symmetrical protrusion 211' is formed on the upper part 211a of the main body, so that the groove 2
39 (dovetail groove) is formed, while the slider 21
9 has a pair of protrusions 21 extending parallel to each other on both sides.
9' is formed, and an integral part 217 in which the slider 219 and the cylindrical support member 224 are integrated.
is slidably guided by the groove 239.

A pin 234 is provided vertically movably through this integral part 217, and the pin flange 23
5 and the cylindrical support member 224, it is constantly urged downward by a compression spring 236. In addition, several positioning holes 231 are formed at predetermined intervals on the bottom surface of the main body protrusion 211'.
The lower end portion 234' of the pin is adapted to fit into one of these positioning holes 231. Note that a knob 226 is provided at the upper end of the pin 234, and by pinching and pulling up this knob 226, the pin lower end 234' can be pulled out from the positioning hole 231, and the handle 226 in the pulled up state can be moved to a predetermined position. Turn the angle and insert the pin 22 on the lower end surface.
5, the pin 234 can be maintained in a pulled up state.

Returning to FIG. 1, a protrusion 221 protruding in the radial direction is formed at one end in the circumferential direction (bending start part) of the rotating former 213, and a pipe holder 222 is rotated by a vertical pin 223 at the tip of the protrusion 221. installed as possible. A semicircular holding groove 222' is formed in this pipe holder 222, which restrains the tip of the pipe t between it and the rotary former 213, and when the rotary former 213 rotates, the pipe t and the rotary former 213 are held together. plays the role of integrally holding the

In addition, as is clear from FIG. 2, the main body 2
11 has an upper stage part 211a and a lower stage part 211b, and the four side surfaces of the lower end part 211b are widened downward, and the bottom part of the main body 211 constitutes a larger installation surface than the upper part.

Next, the method of use and operation of the pipe bending device configured as described above will be explained.

Prior to pipe bending, the cylindrical support member 22, which forms the main body of the bending die support mechanism in FIG.
4 is fixed in one of the plurality of positioning holes 231 of the main body 211 with a pin 234. and,
Hold the tip of the pipe t to be bent in the pipe holder 22
2 and the rotary former 213 and engaged with the holding groove 214 of the rotary former 213. Furthermore, the pipe t and the cylindrical support member 224
A bending die 218 is inserted in a wedge shape between the two and fixed in the state shown in FIG.

In addition, when inserting the bending die 218 between the cylindrical support member 224 and the pipe t, a lever-shaped jig is provided that has a protrusion on the bending die 218 and can be operated using a part of the cylindrical support member 224 as a fulcrum. If the bending die 218 is pushed in by engaging the jig with the projection, the insertion operation becomes easy.

Then, when the motor is started and the rotary former 213 is rotated by a preset angle, the pipe t is restrained by the pipe holder 222 at its tip, so as the rotary former 213 rotates, the pipe t is rotated by the bending die 218. The pipe is fed while sliding against the pipe, and is gradually wound around the holding groove 214 of the rotary former 213, thereby bending the pipe.

In the above-mentioned bending process, the pipe t is passed through the bending die 218, at which time it receives a favorable pressure effect for bending. In particular, tensile stress is temporarily generated in the pipe t almost within the elastic range by the delivery side guide part 246,
It is thought that the bending process progresses gradually in such a state, and as a result, a good bent portion without wrinkles or the like is formed.

This will be further explained with reference to FIG.
The pipe cross section a before bending is
It is thought that in the process of passing through 18, it is temporarily deformed into an oval cross section b. However, this deformation is almost elastic, and in the process of passing through the bending die 218 and being wound around the rotating former 213, the pipe t easily and quickly returns to its original circular cross section a, It is rarely shaped (oblate).

FIG. 6 shows a state in which the pipe t is sandwiched between the rotary former 213 and the bending die 218. According to this, the pipe t temporarily becomes oval-shaped when passing through the delivery side guide section 246. can be estimated.

When the pipe bending device of this embodiment is used to bend a pipe up to 180 degrees, it is possible to bend pipes with a wide range of diameters, for example, from 4 mm to about 35 mm, and in addition, the pipe has a very thin wall thickness. Even in cases where the pipe is bent, it can be bent without a core material, the bent pipe suffers almost no distortion due to tension, and a bent pipe with a smooth surface can be obtained.

When the bending operation is completed, the bending die 218 can be easily removed by rotating the rotary former 213 in the opposite direction, and the bent pipe can therefore be removed from the rotary former 213.

In addition, if the pipe diameter changes, the rotation former 213
The bending die 218 and pipe holder 222 are replaced with ones with a groove diameter that corresponds to the pipe diameter, but even if the bending die 218 and pipe holder 222 do not have a groove diameter that matches the pipe diameter, they can be replaced with ones that have a groove larger than the pipe diameter. If so, it is possible to use it for general purposes to some extent (even if the pipe diameter changes, the bending die 218 and the pipe holder 222 do not change).

Second Embodiment Next, regarding the second embodiment, Figs.
This will be explained based on the diagram. The major difference between the second embodiment and the first embodiment is that, as is clear from FIG.
4, and the shape of the guide groove 50 of the bending die 118 is different.

The bending die 118 of this embodiment includes a ring-shaped base end 118' that is rotatably supported.
At this proximal end 118', a cylindrical support member 124
The device is rotatable. That is, as shown in FIG. 11, a ring-shaped base end 118' is attached to the upper end of the cylindrical support member 124, and the main body hangs downward from there and connects the pipe t between it and the rotary former 113. It looks like it's going to be pinched.

Further, the cylindrical support member 124 is fixed to the slider 119 as shown in FIG.
A pair of parallel guides 115 functioning as guide portions are fixed on the slider 11, and a slider 119 is slidably mounted on the parallel guides 115 in a pair of grooves 139 formed on both sides thereof. Similarly to the first embodiment, this cylindrical support member 124 also has a pin 134 connected to a flange 135 and a shoulder surface 124''.
It is provided in a state where it is always urged downward by a compression spring 136 provided between. Further, a plurality of positioning holes 131 are provided on the upper surface of the main body 111 at predetermined intervals.

As is clear from FIGS. 8 and 9, behind the integral part 117 in which the cylindrical support member 124 and the slider 119 are integrated, this integral part 117
A mechanism for pressing the bending die 118 against the pipe t is provided. That is, the base block 12 is connected to the pair of parallel guides 115.
9 is slidably provided, and this base block 1
The base block 129 is selectively fixed at a plurality of locations by fitting pins 129' (FIG. 9) provided in the base block 29 into the aforementioned positioning holes 131. This base block 12
A screw shaft 132 is screwed into the cylindrical support member 124, and its tip abuts against a notch 132' (see FIGS. 10 and 11) formed in the cylindrical support member 124.
Therefore, when the knob 133 of the screw shaft 132 is turned, the bending die 118 is pressed against the pipe t via the cylindrical support member 124 due to the screw action.

Note that the pin 134 provided on the cylindrical support member 124 in FIG. 10 is normally maintained in a raised state by the vertical pin 125;
This allows the cylindrical support member 124 to be used as a jig for the bending die 218 of the first embodiment.

As shown in FIG. 8, bending die 118
The guide groove 50 has an arcuate shape in the longitudinal direction of the groove. And the delivery side guide part 11
8a is a short straight line section from a to b in the figure, and its semicircular groove bottom gradually approaches the pipe t toward the a end. Further, an arcuate relief portion 118b that does not contact the pipe t is formed continuously on the upstream side from the delivery side guide portion 118a, and the delivery side end of this relief portion 118b is used as a delivery side guide portion c. The radius of the arcuate relief portion 118b of the bending die 118b is larger than the bending radius of the rotary former 113, and is between b and c in FIG. In the entire section a-c, the delivery side guide portion 118a has a slight downward slope, so when the pipe t is installed between the rotating former 113 and the bending die 118, the bending die 118 and the pipe t Contact occurs only at points a and c at both ends.
In other words, there is no contact with the pipe t at the intermediate point b. In this part, a clearance is generated on the order of, for example, 1/10 of 1 mm.

The pipe holder 122 is attached to the protrusion plate 121 by a pin 123, and the protrusion plate 1
21 is pin 139, bolt 137 and nut 13
It is removably fixed to the rotary former 113 at two points, 8 and 8.

Next, the action will be explained.

At the initial stage when the rotary former 113 starts rotating, the pipe holder 122 is not yet in a clamped state with the pipe t, and in this state, the rotary former 113 indicates the actual bending start point of the pipe.
The zero point on the upper scale does not match the zero point on the scale of the bending die 118.

When the rotary former 113 further rotates, the pipe t is clamped by the pipe holder 122, and the bending die 118
The contact between the pipe p and the bending die 118 continues at point c, while the contact between the pipe t and the point a of the bending die 118 gradually progresses along the delivery side guide portion 118a. Therefore, when the bending of the pipe t is started, the 0 point of the bending die 118 is aligned with the 0 point of the rotary former 113, and the actual bending process is then started, and the pipe t is moved toward the delivery side guide. It advances while being subjected to a certain amount of lateral pressure by the portion 118a. Therefore, as shown in Fig. 12, the pipe cross section d before bending is thought to temporarily deform into an oval cross section e under the bending action.
The action of this delivery-side guide portion 118a occurs gradually, and since the stress generated in the pipe t is approximately within the elastic limit, the bending die 118 moves the pipe t
When released, it returns to its original circular cross section d. The pipes bent in this way do not show any damage, wrinkles, or flattening, even if the diameter of the pipe being bent is larger than that, the wall thickness is thin, or the material of the pipe is under tensile stress. On the other hand, it is possible to obtain pipe bends with smooth surfaces even if the pipe is susceptible to this.

In addition, for the cylindrical support member 124 or 224 of the first embodiment or the second embodiment, a pulley-shaped bending guide roller that can be replaced with the bending die 118 or 218 described above is prepared. It is also possible to selectively use the bending guide roller and the bending guide roller depending on the type of pipe. In that case, use bending dies 118 and 218 for thin-walled pipes,
Bending guide rollers can be used for thick-walled pipes.

The embodiments described above are literally illustrative;
It goes without saying that the present invention can be implemented with various modifications and improvements based on the common knowledge of those skilled in the art.

[Brief explanation of drawings]

1 to 7 show a first embodiment of the present invention.
Fig. 1 is a plan view of a pipe bending device as an embodiment, Fig. 2 is a side view thereof, Fig. 3 is a sectional view of the bending die support mechanism, Fig. 4 is a sectional view of the bending die, and Fig. 5 is a sectional view of the bending die. The figure is an explanatory diagram comparing the depth of the groove of the bending die at the inlet end and the outlet end, Figure 6 is a sectional view taken from 16-16 in Figure 1, and Figure 7 is a pipe bending diagram. It is an explanatory diagram of operation during processing. 8 to 12 show a second embodiment. 8th
The figure is a plan view of a pipe bending device that is a second embodiment, FIG. 9 is a side view thereof, FIG. 10 is a front view of the bending die support mechanism, and FIG. 11 is a cross section showing the form of support for the bending die. Figure 12 is the second
FIG. 3 is an explanatory diagram of the operation during pipe bending in the embodiment. 110,210...pipe bending device, 111,2
11...Main body, 113, 213...Rotation former, 5
0,260...Guide groove, 122,222...Pipe holder, 114,214...Holding groove, 118,21
8...Bending die, 119,219...Slider.

Claims (1)

[Scope of Claims] 1. An electric pipe bending device for bending a pipe, which comprises a main body 111, 211, a motor provided in the main body, a speed reducer that reduces the rotation of the motor, and a bending curve. A rotary former having a corresponding bent outer peripheral surface, fixed to the output shaft 112 of the speed reducer at its center, and having holding grooves 114, 214 formed along the bent outer peripheral surface corresponding to the bent cross section of the pipe. 113, 213, and a guide groove 50, 260 that is installed at a fixed position so as to sandwich the pipe between the rotary former and guides the pipe while sliding it in the axial direction almost opposite to the holding groove of the rotary former. a bending die support mechanism 124, 224 for positioning the bending die at a predetermined position corresponding to the pipe diameter with respect to the rotary former; An electric pipe bending device characterized by comprising pipe holders 122, 222 that hold the vicinity of the bending start part of the pipe and keep the pipe integral with the rotating former when the rotating former rotates. 2 The rotating former 113, 213, the bending die 118, 218, and the pipe holder 12
2. The device according to claim 1, wherein the pipes 2 and 224 are each replaceable depending on the pipe diameter. 3. The apparatus of claim 1, wherein the bending die 118, 218 and the pipe holder 122, 222 have grooves of universal size to accommodate different outside diameters of pipes. 4. The guide grooves 50, 260 of the bending dies 118, 218 extend along the pipe feeding direction, and the guide grooves are formed at the end of the pipe feeding side. ,245
, a delivery side guide part 118a, 246 formed at the end of the pipe delivery side, and a relief part 118b, 248 that faces the pipe with a certain clearance without contacting the pipe in the middle thereof. 4. The device according to any one of claims 1 to 3, wherein the groove bottom of the delivery-side guide portion is formed so as to gradually approach the pipe toward the delivery-side end. 5 Bending die support mechanism 124, 224 that supports the bending die 118, 218
However, the bending die is rotated by the rotating former 1.
5. The device according to claim 1, wherein the device is adapted to be supported rotatably around an axis parallel to the rotation axis of the device. 6. Claims in which the bending die 118, 218 is inserted in a wedge shape between the bending die support mechanism 124, 224 and the pipe, and is held in a compressed state by feeding the pipe to guide the pipe. The device according to any one of paragraphs 1 to 5. 7 The bending die support mechanism 124, 22
4 includes sliders 119, 219, which sliders are guided by guide portions 115, 239 formed in the main bodies 111, 211 to move the rotary former 11.
3,213 so that it can be approached and separated,
Claims 1 to 6 further include fixing means 131, 134: 231, 234 for positioning and fixing the slider at a position corresponding to the pipe diameter between the slider and the main body.
Apparatus according to any of paragraphs. 8 The bending die support mechanism 124, 22
4 can selectively support the bending dies 118, 218 and the rotatable bending guide roller, and the bending die can be used to mainly bend thin-walled pipes, and the bending guide roller can be used to bend thin-walled pipes. 8. The apparatus according to claim 1, wherein the apparatus is mainly used for bending thick-walled pipes.