JP6729929B2 - Tube expansion device - Google Patents

Description

The present invention relates to a pipe expanding device that expands an opening portion of a metal pipe.

BACKGROUND ART Conventionally, for example, a tube expanding device disclosed in Patent Document 1 includes a clamp type for fixing a metal tube and a punch type capable of press-fitting into a metal tube fixed to the clamp type from one of its openings. A plurality of punch dies having different outer sizes are prepared. Then, the punch dies are press-fitted from one opening of the metal pipe in order from the one having the smallest outer shape, and one side of the metal pipe is gradually expanded outward in the outer peripheral surface of the punch dies, whereby cracks or cracks occur. The metal tube is expanded into a desired shape without causing cracks.

JP, 2010-227988, A

However, since the pipe expanding device of Patent Document 1 expands the metal pipe by using a plurality of punch dies, the punch dies to be used are sequentially moved to the press-fitting start position with respect to the metal pipe, and the central axis of the punch dies to be used. There is a problem that it is necessary to perform the operation of aligning with the cylinder center line of the metal tube, the structure is complicated and the cost increases, and the processing time becomes long.

In order to avoid this, it is possible to reduce the number of punch dies, but if you simply reduce the number of punch dies, the elongation of the base material of the metal pipe cannot follow the amount by which the punch dies stretch the metal pipe. There is a risk that cracks and cracks will occur frequently.

The present invention has been made in view of such points, and an object of the present invention is to provide a pipe expanding device that does not generate cracks or cracks during pipe expanding processing, is low cost, and has a short processing time. To provide.

In order to achieve the above-mentioned object, the present invention is characterized in that a punch type press-fitting operation for expanding a metal tube is devised.

Specifically, a fixing portion that contacts the outer peripheral surface of one end side of the metal pipe to fix the metal pipe, and an outer periphery of the other end of the metal pipe that is provided continuously to the fixing portion and is fixed to the fixing portion. A clamp die having a non-fixed portion that forms a gap in the circumferential direction between the surface and a surface, a punch die provided so as to be press fit into the metal tube fixed to the clamp die from the other end opening, and the punch. The mold is provided with advancing/retreating means for advancing or retracting toward the metal tube fixed to the clamp die, and control means connected to the advancing/retreating means for outputting an operation signal to the advancing/retreating means, the control means being the above-mentioned. By outputting an advance start signal to the advancing/retreating means and press-fitting the punch die into the metal tube through the other end opening, the punch die causes the other end side of the metal tube to extend radially outward along the non-fixed portion. For the tube expanding device configured to be pushed out, the following solution measures were taken.

That is, according to the first aspect of the present invention, further provided is an entrance position detecting means for detecting an entrance position of the punch die, and the control means advances the punch die while the punch die is press-fitted into the metal tube. An operation signal is output to the advancing/retreating means so that the operation is intermittent, and the control means controls the pressure applied to the metal tube by the punch die by the approach position detecting means. It is characterized in that an operation signal is output to the advancing/retreating means so that a predetermined set pressure value corresponding to the approach position is obtained .

According to a second aspect of the present invention, in the first aspect of the present invention, the control means causes the advance/retreat operation to alternately repeat the advancing operation and the retreating operation of the punch die in the process of press-fitting the punch die into the metal tube. It is characterized by outputting an actuation signal to the means.

In a third aspect based on the first or second aspect, a lubricant injection means for injecting a lubricant toward the other end of the metal pipe fixed to the fixing portion is provided laterally of the clamp die. It is characterized by being arranged.

In a fourth aspect based on any one of the first to third aspects, the advancing and retracting means is a fluid pressure cylinder, and the fluid pressure cylinder has a cylinder chamber in which fluid is supplied and recovered. A main body, a partition plate for partitioning the cylinder chamber in the cylinder main body into a first chamber far from the punch die and a second chamber close to the punch die, and a first pressure for detecting the pressure in the first chamber. The control unit includes a detection unit and a second pressure detection unit that detects the pressure in the second chamber, and the control unit detects the pressure applied to the metal tube by the punch mold by the entry position detection unit. Based on the detection values of the first pressure detection means and the second pressure detection means, the first chamber and the second pressure detection means are set to have a predetermined set pressure value corresponding to the punch-type entry position. It is characterized in that the amount of fluid supplied to or collected from the two chambers is adjusted.

According to the first aspect of the invention, since the punch die does not continuously perform the advancing operation in the process of press-fitting the punch die into the metal tube, when the punch die begins to re-advance in the metal tube, the punch die is pressed against the metal tube. Impact load will be applied in the advancing direction. Therefore, the amount of compressive deformation of the metal tube along the cylinder center line becomes larger than that in the case where the punch die is continuously advanced to the metal tube, and even if the punch die pushes the metal tube outward in the radial direction. The plate thickness of the metal tube does not become too thin, and it is possible to make it difficult for cracks or cracks to occur in the metal tube. Further, since it is not necessary to use a plurality of punch dies when expanding the metal tube, the punch dies to be used can be sequentially moved to the press-fitting start position with respect to the metal tube, or the central axis of the punch dies to be used can be set to the metal tube. The operation of aligning with the center line of the cylinder is not required, the structure of the device is simpler than that of the device of Patent Document 1, the cost can be suppressed low, and the processing time can be shortened.

In the second aspect of the invention, in the process of press-fitting the punch die into the metal tube, the punch die moves backward during the advance operation, so when the punch die retreats and comes into contact with the metal tube again, The impact load applied to the pipe in the punch-type advancing direction is further increased. Therefore, the amount of compressive deformation along the cylinder center line of the metal pipe during the pipe expanding process is further increased, and the plate thickness of the metal pipe is rapidly thinned when the outer peripheral surface of the punch die pushes the metal pipe radially outward. The number of locations can be reduced, and pipe expanding can be performed without causing cracks or cracks in the pipe expanding portion.

In the third invention, when the punch die stops or retracts in the process of press-fitting the punch die into the metal tube, the lubricant injected by the lubricant injecting means causes the lubricant to be applied to the inner peripheral surface of the metal tube and the outer peripheral surface of the punch die. Will come in between. Therefore, when the punch die retreats in the process of press-fitting the punch die into the metal tube and spreads the metal tube on the outer peripheral surface of the punch die, the gap between the inner peripheral surface of the metal tube and the outer peripheral surface of the punch die is increased. Since the frictional resistance is reduced and the metal pipe is stably stretched, it is possible to reliably prevent the metal pipe from cracking.

It is a cross-sectional schematic diagram of the tube expansion apparatus which concerns on embodiment of this invention. It is a figure which shows the state which, after the state of FIG. 1, press-fits the punch die|dye into the metal pipe fixed to the fixed die|dye, and started expanding the metal pipe. It is a figure which shows the state which the punch type|mold retracted a little after the state of FIG. It is a figure which shows the state which the punch type|mold advanced again after the state of FIG. 3, and expanded the metal tube. It is a graph which shows the relationship between the detection value of the advance position detection sensor and the detection value of the 1st pressure sensor at the time of pipe expansion processing.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. It should be noted that the following description of the preferred embodiments is merely exemplary in nature.

FIG. 1 is a schematic sectional view of a tube expanding device 1 according to an embodiment of the present invention. The pipe expanding device 1 is installed in a production line of a fuel oil supply pipe (not shown) incorporated in a vehicle, and is for expanding the end portion of the metal pipe 10. The clamp mold 2 for fixing the metal pipe 10 is provided. Equipped with.

The clamp die 2 is divided into an upper die 3 and a lower die 4 each having a substantially rectangular parallelepiped shape at a substantially central position in the vertical direction.

A first concave surface 31 having a semicircular cross section corresponding to the upper half portion of the metal tube 10 in which the cylinder centerline C1 is oriented in the horizontal direction is provided in a portion of the lower surface of the upper mold 3 extending from one end in the horizontal direction to the midway portion. Are formed.

A second concave surface 32 having a semicircular cross section is formed on the other side of the lower surface of the upper die 3 in the horizontal direction.

The second concave surface 32 has one end in the horizontal direction that is continuous with the first concave surface 31 and has an inclined extending surface 32a that gradually increases in diameter toward the other end in the horizontal direction. A horizontal extension surface 32b that is continuous with the other end of the output surface 32a in the horizontal direction and extends in the horizontal direction is provided.

Since the lower mold 4 has the same structure as the upper mold 3 and is only arranged so as to be vertically symmetrical in a side view, the same reference numeral as that of the upper mold 3 is used. The detailed description is omitted.

Then, the first concave surface 31 of the upper mold 3 and the first concave surface 31 of the lower mold 4 constitute the fixing portion 11 of the present invention, and the clamp center of the clamp mold 2 is opened in the cylinder center. When the metal pipe 10 with the line C1 oriented in the horizontal direction is inserted between the upper mold 3 and the lower mold 4 and the clamp mold 2 is closed, the fixing portion 11 is fixed to the one end side of the metal pipe 10. The metal pipe 10 is fixed by coming into contact with the outer peripheral surface of the middle part.

Further, the second concave surface 32 of the upper mold 3 and the second concave surface 32 of the lower mold 4 constitute the non-fixed portion 12 of the present invention, and the non-fixed portion 12 includes the metal pipe 10 described above. In the state of being fixed to the fixed portion 11, it has a hole shape that is continuous with the fixed portion 11 and that the opposite side of the fixed portion 11 is open. The non-fixed portion 12 does not contact the outer peripheral surface of the other end of the metal tube 10 and forms a gap S1 between the outer peripheral surface and the outer peripheral surface in the circumferential direction.

A press-fitting machine 5 is arranged laterally on the non-fixing portion 12 side of the clamp die 2.

The press-fitting machine 5 has a substantially cylindrical punch die 6 whose center axis C2 is aligned with the cylinder center line C1 of the metal tube 10 fixed to the clamp die 2, and the punch die 6 fixed to the clamp die 2. Also, a fluid pressure cylinder 7 that advances or retracts toward the metal tube 10 and a cylinder drive device 8 that drives the fluid pressure cylinder 7 are provided.

When the punch die 6 advances toward the metal tube 10 fixed to the clamp die 2 by the fluid pressure cylinder 7, the punch die 6 is press-fitted into the metal tube 10 from the other end opening.

In the punch die 6, a small diameter portion 6a, a molding surface portion 6b and a large diameter portion 6c are sequentially formed from the tip side of the punch die 6.

The outer peripheral surface of the small diameter portion 6a corresponds to the inner peripheral surface of the metal tube 10, and when the punch die 6 is press-fitted into the metal tube 10, the punch die 6 is smoothly inserted into the metal tube 10. It is supposed to guide you.

The molding surface portion 6b is provided at a position near the tip of the punch die 6, and the outer peripheral surface thereof gradually increases in diameter toward the side opposite to the press-fitting direction.

The large-diameter portion 6c is provided from the position near the tip of the punch die 6 to the base end, and the outer peripheral surface thereof extends straight in the horizontal direction.

The fluid pressure cylinder 7 includes a cylindrical cylinder body 71 whose center axis coincides with the center axis C2 of the punch die 6, and a cylinder chamber 70 is formed inside the cylinder body 71.

A communication hole 71a communicating with the cylinder chamber 70 is formed in the center of one end of the cylinder body 71, and a slender rod-shaped piston rod 72 is slidably fitted in the communication hole 71a.

One end of the piston rod 72 is fixed to the center of the base end of the punch die 6, and the piston rod 72 slides so that the punch die 6 faces the metal tube 10 fixed to the clamp die 2. To advance or retreat.

On the other hand, a partition plate 72a extending in a direction orthogonal to the piston rod 72 is fixed to the other end of the piston rod 72.

The partition plate 72a divides the cylinder chamber 70 into a first chamber 70a farther from the punch die 6 and a second chamber 70b closer to the punch die 6.

The first chamber 70a is provided with a first pressure sensor 73a for detecting the pressure of the first chamber 70a, while the second chamber 70b is provided with a second pressure for detecting the pressure of the second chamber 70b. The sensor 73b is arranged.

Further, at a position corresponding to the piston rod 72 in the second chamber 70b, an advance position detection sensor 74 for detecting the advance position of the punch die 6 by detecting the slide amount of the piston rod 72 is arranged. ing.

The cylinder drive device 8 is connected to a drive device body 81 capable of supplying or recovering a fluid, one end of which is connected to the first chamber 70a of the cylinder chamber 70, and the other end of which is connected to the drive device body 81. One pipe 82 and a second pipe 83 having one end connected to the second chamber 70b of the cylinder chamber 70 and the other end connected to the drive device main body 81 are provided.

The fluid pressure cylinder 7 and the cylinder drive device 8 constitute the advancing/retreating means 13 of the present invention, and the piston rod 72 is provided with the first rod 82 from the drive device main body 81 through the first pipe 82. When the fluid is supplied to the chamber 70a and the fluid is recovered from the second chamber 70b to the drive device main body 81 through the second pipe 83, the punch die 6 is slid to one side to advance and the drive is performed. When the fluid is supplied from the device main body 81 to the second chamber 70b via the second pipe 83 and the fluid is recovered from the first chamber 70a to the drive device main body 81 via the first pipe 82, the other side is obtained. The punch die 6 is slid back to retreat.

The drive device main body 81 has a switching portion 81a that changes the sliding direction of the piston rod 72 by switching the supply and recovery of the fluid to and from the first chamber 70a and the second chamber 70b.

A lubricant injection device 9 (a lubricant injection means) that injects a lubricant toward the other end of the metal tube 10 fixed to the fixed portion 11 is provided on the side of the clamp die 2 on the punch die 6 side. It is arranged.

A control panel 14 (control means) is connected to the first pressure sensor 73a, the second pressure sensor 73b, the advance position detection sensor 74, the cylinder drive device 8 and the lubricant injection device 9, and the control panel is connected to the control panel 14. 14 outputs an operation signal to the cylinder drive device 8 and the lubricant injection device 9.

The control board 14 outputs an advance start signal to the advancing/retreating means 13 to press the punch die 6 into the metal tube 10 from the other end opening, so that the punch die 6 is at the other end side of the metal tube 10. Is pushed outward in the radial direction until it extends along the non-fixed portion 12.

Further, the control board 14 can detect the advance position of the punch die 6 based on the value detected by the advance position detection sensor 74.

Further, the control panel 14 sets the first pressure sensor 73a and the second pressure so that the preset pressure value at the time of press-fitting corresponding to the advance position of the punch die 6 detected by the advance-position detecting sensor 74 becomes a predetermined pressure value. The pressure applied by the punch die 6 to the metal tube 10 is changed while adjusting the amount of fluid supplied to or collected from the first chamber 70a and the second chamber 70b based on the detection value of the sensor 73b. Has become.

In addition, the control board 14 sends an operation signal to the lubricant injection device 9 so that the lubricant is injected from the lubricant injection device 9 while the punch die 6 is being press-fitted into the metal tube 10. Is to be output.

As shown in FIGS. 2, 3 and 5, the control board 14 causes the punch die 6 to move out intermittently while the punch die 6 is being press-fitted into the metal tube 10. As described above, an operation signal is output to the advancing/retreating means 13.

Specifically, the control board 14 moves the punching die 6 into the metal tube 10 under pressure, and the advancing/retreating means 13 so that the advancing and retracting operations of the punching die 6 are alternately repeated. The operation signal is output to.

Next, the pipe expanding process of the metal pipe 10 using the pipe expanding device 1 will be described in detail.

First, the metal tube 10 with the cylinder center line C1 extending horizontally is inserted between the upper mold 3 and the lower mold 4 of the clamp mold 2.

Next, as shown in FIG. 1, the clamp mold 2 is closed. Then, the fixing portion 11 of the clamp die 2 comes into contact with the outer peripheral surface of the middle portion from the one end side of the metal pipe 10 to fix the metal pipe 10.

At this time, a gap S1 is formed between the outer peripheral surface of the metal tube 10 on the other end side and the inner peripheral surface of the non-fixed portion 12.

Next, the lubricant is injected from the lubricant injection device 9 toward the other end of the metal tube 10 fixed to the clamp die 2.

After that, the punch die 6 is advanced toward the clamp die 2. Then, first, the small diameter portion 6 a of the punch die 6 is inserted into the other end opening of the metal tube 10.

When the punch die 6 is further advanced, the other end of the metal tube 10 is pushed outward by the forming surface portion 6b in the radial direction. At this time, as shown in FIG. 5, the cylinder drive device 8 is controlled so that the pressure when the punch die 6 is press-fitted into the metal tube 10 becomes a predetermined set pressure P0.

Here, as shown in FIG. 3, when the punch die 6 advances to a predetermined position, the punch die 6 is slightly retracted, and then is advanced again to be controlled by the cylinder drive device 8 to restart the press-fitting operation to the metal tube 10. .. Then, as shown in FIG. 4, while the punch die 6 is being advanced and retracted 5 times at high speed, the other end side of the metal tube 10 is gradually expanded by the molding surface portion 6b so that the non-fixed portion 12 of the clamp die 2 is released. Shape along the inner surface. The relationship between the detection value of the advance position detection sensor 74 and the detection value of the first pressure sensor 73a during this press-fitting work is as shown in FIG.

As described above, according to the embodiment of the present invention, since the punch die 6 does not continuously perform the advancing operation in the process of press-fitting the punch die 6 into the metal tube 10, the punch die 6 re-expands in the metal tube 10. When starting, an impact load is applied to the metal tube 10 in the advancing direction of the punch die 6. Therefore, the amount of compressive deformation of the metal tube 10 along the cylinder centerline C1 is increased as compared with the case where the punch die 6 is continuously advanced to the metal tube 10, and the punch die 6 radially moves the metal tube 10. Even if it is pushed outward, the plate thickness of the metal tube 10 does not become too thin, and the metal tube 10 is less likely to crack or crack.

Further, since it is not necessary to use a plurality of punch dies 6 when expanding the metal tube 10, the punch dies 6 to be used are sequentially moved to the press-fitting start position with respect to the metal tubing 10, or the punch dies 6 to be used are not used. The operation of aligning the central axis C2 with the cylinder center line C1 of the metal tube 10 is not necessary, the structure of the tube expanding device 1 is simpler than that of the device of Patent Document 1, and the cost can be kept low, and machining is possible. The time can be shortened.

Further, in the process of press-fitting the punch die 6 into the metal tube 10, the punch die 6 retreats in the middle of its advancing operation, so when the punch die 6 retreats and comes into contact with the metal tube 10, The impact load applied to the metal tube 10 in the advancing direction of the punch die 6 is further increased. Therefore, the amount of compressive deformation along the cylinder center line C1 of the metal pipe 10 during the pipe expanding process is further increased, and the plate thickness of the metal pipe 10 rapidly increases when the forming surface portion 6b pushes the metal pipe 10 outward in the radial direction. By reducing the number of thinned portions, it is possible to perform pipe expanding processing without causing cracks or cracks in the pipe expanding portion.

Further, when the punch die 6 retracts in the process of press-fitting the punch die 6 into the metal tube 10, the lubricant injected by the lubricant injection device 9 causes the inner peripheral surface of the metal tube 10 and the outer peripheral surface of the punch die 6 to come together. Will come in between. Therefore, when the punch die 6 advances again in the process of press-fitting the punch die 6 into the metal tube 10 and pushes the metal tube 10 on the outer peripheral surface of the punch die 6, the inner peripheral surface of the metal tube 10 and the outer periphery of the punch die 6 are Since the frictional resistance between the metal pipe 10 and the surface is reduced and the metal pipe 10 is stably stretched, it is possible to reliably prevent the metal pipe 10 from cracking.

In the embodiment of the present invention, when the punch die 6 advances to a predetermined position in the process of press-fitting the punch die 6 into the metal tube 10, the punch die 6 slightly retracts and then re-extends. However, not limited to this, when the punch die 6 advances to a predetermined position, the punch die 6 may stop a little and then advance again.

Further, in the embodiment of the present invention, the punch die 6 is advanced and retracted 5 times during the process of press-fitting the punch die 6 into the metal tube 10. However, the invention is not limited to this, and the punch die 6 is advanced. The backward movement may be performed 1 to 4 times, or 6 times or more.

INDUSTRIAL APPLICATION This invention is suitable for the pipe expansion apparatus which expands the opening part of a metal pipe.

1 Tube Expansion Device 2 Clamp Type 6 Punch Type 9 Lubricant Injection Device (Lubricant Injection Means)
10 metal tube 11 fixed part 12 non-fixed part 13 advance/retreat means 14 control panel (control means)
S1 gap

Claims (4)

Between the outer peripheral surface of the metal pipe which is fixed to the fixed portion and the fixed portion which is fixed to the fixed portion by contacting the outer peripheral surface of the metal pipe on one end side, and which is fixed to the fixed portion. A clamp type having a non-fixed portion that forms a gap over the circumferential direction,
A punch die provided so as to be press-fitted from the other end opening to the metal tube fixed to the clamp die,
Advancing and retracting means for advancing or retracting the punch die toward the metal tube fixed to the clamp die,
A control means connected to the advancing/retreating means and outputting an operation signal to the advancing/retreating means,
The control means outputs an advancing start signal to the advancing/retreating means and press-fits the punch die into the metal tube from the other end opening, whereby the punch die follows the other end side of the metal tube along the non-fixed portion. A tube expanding device configured to push outward in the radial direction to
Further comprising an entry position detection means for detecting the entry position of the punch die,
The control means outputs an actuation signal to the advancing/retreating means so that the advancing operation of the punch die is intermittent in the process of press-fitting the punch die into the metal tube ,
Further, the control means, so that the pressure applied to the metal tube by the punch mold becomes a predetermined set pressure value corresponding to the entrance position of the punch mold detected by the entrance position detection means, A pipe expanding device which outputs an operation signal to the advancing/retreating means . The tube expanding device according to claim 1,
The control means outputs an actuation signal to the advancing/retreating means so that, in the process of press-fitting the punch die into the metal tube, the advancing and retracting operations of the punch die are alternately repeated. Tube expansion device. The tube expanding device according to claim 1 or 2,
A pipe expanding device characterized in that a lubricant injecting means for injecting a lubricant toward the other end of the metal pipe fixed to the fixing portion is arranged laterally of the clamp type. In the tube expanding device according to any one of claims 1 to 3,
The advancing and retracting means is a fluid pressure cylinder,
The fluid pressure cylinder is
A cylinder body having a cylinder chamber for supplying and collecting fluid,
A partition plate for partitioning the cylinder chamber in the cylinder body into a first chamber far from the punch die and a second chamber near the punch die;
First pressure detecting means for detecting the pressure in the first chamber,
Second pressure detecting means for detecting the pressure in the second chamber,
Have
The control means sets the pressure applied by the punch die to the metal tube to a predetermined set pressure value corresponding to the entry position of the punch die detected by the entry position detection means. A pipe expanding device, wherein the amount of fluid supplied to or recovered from the first chamber and the second chamber is adjusted based on the detection values of the first pressure detecting device and the second pressure detecting device.

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