JPS6343162B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an apparatus for processing the inner and outer surfaces of a metal tube, which gives a desired shape to the inner and outer surfaces of the metal tube.

For example, heat exchangers use heat exchanger tubes such as finch tubes and corrugated tubes, which are metal tubes with fins, protrusions, grooves, etc. on the inner and outer surfaces of the tubes in order to improve heat transfer properties.

By the way, conventionally, in order to process a simple metal tube into a metal tube with such a shape, the metal tube is first processed to a predetermined pipe diameter and thickness, and then extrusion processing, drawing processing,
A method of further imparting a predetermined shape to the inner and outer surfaces of this metal tube by rolling or the like has been used.

However, in such processing methods,
The process of making the metal tube a predetermined diameter and thickness and the process of imparting a predetermined shape to the inner and outer surfaces of the metal tube are separate processes, and it is desirable to perform these processes in a single process. was. Additionally, there are problems with extrusion, drawing, and rolling, which are used in the process of imparting a predetermined shape to the inner and outer surfaces of a metal tube. For example, in extrusion and drawing, it is difficult to obtain precisely shaped grooves or protrusions that improve heat transfer, and large forces are applied to the metal tube during extrusion and drawing. The disadvantage was that the metal tube was easily damaged due to the action.

In addition, in the case of rolling processing in which deep grooves of fins or corrugates are formed on the inner and outer surfaces of the metal tube, when the roll of the rolling machine rotates, the deep grooves of fins or corrugates formed on the inner and outer surfaces of the metal tube are formed. The grooves fit with the rolls to restrain the metal tube, and this restraining force naturally applies feed to the metal tube without any special operation. When manufacturing metal tubes with very fine uneven patterns, or metal tubes with a smooth outer surface and shallow spiral protrusions on the inner surface, there is a risk that the restraining force of the metal tube by the rolls will weaken and productivity will decrease. Therefore, it is particularly desirable to strengthen the restraining force of the metal tube to apply sufficient feed to the metal tube, and it is also desired that the shapes given to the inner and outer surfaces of the metal tube be accurate.

This invention was made in view of the above circumstances,
The process of processing a metal tube to a predetermined pipe diameter and thickness, and the process of imparting a predetermined shape to the inner and outer surfaces of the metal pipe, can be performed in a single process without special extrusion or drawing of the metal pipe. It can be done in the process of
In addition, the metal tube can be sufficiently and stably fed by using a roll unit that presses the metal tube from the outside against its outer peripheral surface as a roll unit consisting of a rolling roll, a feed roll, and a guide roll that are formed separately from each other. As a result, even if the shape given to the inner and outer surfaces of the metal tube is minute, the shape can be made accurate, and the productivity of metal tubes can be greatly improved. Another object of the present invention is to provide an apparatus for processing the inner and outer surfaces of metal tubes, which can reduce the cost of rolling rolls and the like.

An embodiment of the present invention will be described below with reference to FIGS. 1 to 3. 1 in FIG. 1 indicates a plurality of predetermined locations above the base (not shown), for example, three locations.
This frame body 1 is connected to and supported by a cylinder mechanism 2 attached to a base. In the frame 1, a rolling roll 3, a feed roll 4, and a guide roll 5 located on the left and right sides of the rolling roll 3 in FIG. 1, respectively, are rotatably provided via a shaft 6. The rolling roll 3 and the feed rolls 4 and guide rolls 5 located in front and behind the rolling roll 3 are combined one by one to form a set of roll units, and in this embodiment, this roll unit is a frame. A total of three sets are equipped, one set for each body. Both the feed roll 4 and the guide roll 5 are made of hard urethane rubber, and the outer diameter of the feed roll 4 is approximately the same as or slightly smaller than the outer diameter of the rolling roll 3. Largely formed. A metal tube 7, which is a workpiece, is disposed so as to penetrate through the inner center of each rolling roll 3, each feed roll 4, and each guide roll 5. That is, a plurality of shafts, for example, three shafts 6, are arranged on the circumference centered on the axis 8 of the metal tube 7, spaced apart in the circumferential direction. ,
The guide roll 5 is now attached. By the operation of the cylinder mechanism 2, each rolling roll 3, each feed roll 4, and each guide roll 5 are simultaneously pressed against the outer peripheral surface of the metal tube 7. Further, the rolling roll 3, feed roll 4, and guide roll 5 are arranged at an inclination angle θ with respect to the axis 8 of the metal tube 7, as shown in FIG. Note that the magnitude of this inclination angle θ is adjustable. The outer circumferential surface of the rolling roll 3 is formed into an arcuate shape at both ends in the axial direction, as shown in FIG. In addition, as the rolling roll 3, as shown in FIG. 2a, the outer circumferential surface is a smooth surface 9 without unevenness, and as shown in FIG. 2b, fine spiral grooves 10 are formed on the outer circumferential surface. As shown in FIG. 2c, there are two types of grooves, one in which minute double spiral grooves 11 intersecting with each other are formed on the outer peripheral surface, and one in which fine fins 12 are formed on the outer peripheral surface as shown in FIG. 2d. Provided.

In addition, a gear 1 is provided on the left side of the frame 1 in FIG.
3 is provided. A through hole 14 is formed in the center of the gear 13, and the metal tube 7 is inserted through the through hole 14 so as to be relatively rotatable. Further, a belt groove is formed in the boss 15 of the gear 13, and the belt 16 is wound around the belt groove.
The rotational force of the drive source 18 is transmitted to the gear 13 via the transmission 17 and the like. Gear 13
A gear 19 is meshed with and rotatably disposed in the . The shaft 6 is connected to the shaft 20 of the gear 19 via universal joints 21 and 22 and an intermediate shaft 23.

On the other hand, inside the metal tube 7, a processed portion 25 provided at one end of the mandrel 24 inserted into the metal tube 7 is disposed in a floating manner at a position corresponding to the rolling roll 3. The other end (not shown) of the mandrel 24 is rotatably supported by a holder (not shown) provided on the base. A fine predetermined shape (for example, a spiral groove) is formed on the outer peripheral surface of the processed portion 25 .

Next, the operation of the apparatus for machining the inner and outer surfaces of a metal tube having the above structure will be explained. When processing the workpiece, that is, the metal tube 7, first move the piston rod into and out of the cylinder of the cylinder mechanism 2 to expand the inner space of each feed roll 4, each rolling roll 3, and each guide roll 5, and then process the metal tube. 24 mandrels in 7
and fit the metal tube 7 to the mandrel 24, and the through hole 14 of the gear 13, each feed roll 4, the inner center of each rolling roll 3, that is, the three feed rolls 4, and the three rolling rolls. Insert it into the center of the inside of 3.

Next, when the drive source 18 is driven, the transmission 17,
The gear 13 rotates via the belt 16, which causes the gear 19, shaft 20, and universal joint 2 to rotate.
1, 22, a shaft 6 rotates via an intermediate shaft 23, and together with this shaft 6, the feed roll 4, the rolling roll 3,
The guide roll 5 rotates.

Next, when the cylinder mechanism 2 is operated, the piston rod in the cylinder mechanism 2 protrudes and presses each feed roll 4 and each rolling roll 3 against the outer circumferential surface of the metal tube 7.
The rolling roll 3 presses the metal tube 7 against the processed portion 25 of the mandrel 24 while being in pressure contact with the mandrel 24, thereby reducing the diameter of the metal tube 7. Therefore, the processed portion 25 imparts a fine predetermined shape (for example, a fine spiral groove) to the inner circumferential surface of the metal tube 7. At this time, the metal tube 7 is rotated by the feed roll 4 and the rolling roll 3. Further, at this time, each feed roll 4 and each rolling roll 3 are arranged at an angle θ inclined with respect to the axis 8 of the metal tube 7, so that each feed roll 4, each rolling roll 3, and the metal tube 7
A frictional force is generated between the two, and a component of this frictional force in the direction of the axis 8 becomes a driving force that moves the metal tube 7 in the direction of the axis 8. Then, due to this driving force, the metal tube 7
is moved in the direction of arrow A in FIG.
Note that by changing the magnitude of the inclination angle θ with respect to the axis 8, the propulsive force of the metal tube in the direction of the axis 8 by the feed roll 4, rolling roll 3, and guide roll 5 changes. At this time, if the rolling roll 3 is as shown in FIG. 2a, the outer peripheral surface of the metal tube 7 will be a smooth surface with no unevenness, and the rolling roll 3 will be as shown in FIG. 2b. If the rolling roll 3 is of the type shown in FIG. 2c, minute spiral protrusions are formed on the outer peripheral surface of the metal tube 7, Fine double helical protrusions that intersect with each other are formed,
When the rolling roll 3 is as shown in FIG. 2d, minute fins are formed on the outer peripheral surface of the metal tube 7.

The metal tube 7 is rolled by the rolling rolls 3 and fed by the rolling rolls 3 and feed rolls 4 in the direction of arrow A in FIG. Here, since the outer diameter of the guide roll 5 is larger than the outer diameter of the rolling roll 3, the guide roll 5 comes into pressure contact with the metal tube 7, and the guide roll 5 is inclined at a predetermined angle θ with respect to the axis 8 of the metal tube 7. As a result, a frictional force is generated between the guide roll 5 and the metal tube 7, and a component of this frictional force in the direction of the axis 8 moves the metal tube 7 in the direction of arrow A in FIG. In this way, when processing the metal tube 7, the forces of the feed roll 4, rolling roll 3, and guide roll 5 to move the metal tube 7 in the direction of arrow A overlap, so that
Sufficient feed is applied to the metal tube 7. Therefore, the special extrusion process and drawing process of the metal tube 7 are omitted, and the process of processing the metal tube 7 into a predetermined pipe diameter and thickness, and the process of giving a predetermined shape to the inner and outer surfaces of the metal pipe 7 are performed. It can be done in a single step. The guide rolls 5 also serve to guide the metal tube 7 to prevent it from wobbling when it moves in the direction of the arrow A, and also protect the outer peripheral surface of the metal tube 7 to prevent it from being scratched. It also prevents By the way, the rolling roll 3, the feed roll 4, and the guide roll 5 each have the function of diagonally contacting the outer periphery of the metal tube 7 and propelling it in the direction of arrow A. Each has its own unique effect. That is, the rolling roll 3 is
Mainly, the metal tube 7 is processed by the processing section 2 of the mandrel 24.
5 to reduce the diameter of the metal tube 7, and to give the outer peripheral surface of the metal tube 7 a predetermined shape. The feed roll 4 primarily presses against the circumferential surface of the relatively large-diameter metal tube 7 before diameter reduction with a large contact surface, and functions to forcefully propel the metal tube 7 in the direction of arrow A. Guide roll 5
Mainly, the diameter reduction of the metal tube 7 is made uniform in the circumferential direction by guiding the movement of the metal tube 7 immediately after the diameter reduction and giving a predetermined shape to the inner and outer surfaces and preventing the deflection. It functions to guide the position of the metal tube 7 immediately after passing through the rolling rolls 3 to a certain position so that the shape given to the inner and outer surfaces of the metal tube 7 is accurate.

Furthermore, by forming the rolling roll 3, feed roll 4, and guide roll 5 separately, roll costs can be reduced.

In other words, when the external shape of the metal tube to be processed changes, or when changing the inclination angle of the rolling roll 3, when using the rolling roll 3 with the same diameter before and after the change, the feed roll 4
Also, it is necessary to change the diameter of the guide roll 5. In such a case, each roll 3, 4,
If 5 is formed integrally, all of them must be changed at the same time, which increases the roll cost. In this respect, according to the processing apparatus of the present invention in which the rolls 3, 4, and 5 are formed separately, only the feed roll 4 and the guide roll 5 need to be changed, and therefore the cost of the rolls can be reduced. can. Further, the rolling roll 3 has a processed portion 25 provided with a predetermined shape such as a spiral groove, and performs most of the processing of the metal tube. Therefore, it tends to wear out earlier than the other rolls 4 and 5. Even in such a case, if the rolls 3, 4, 5 are formed integrally, all the rolls 3, 4, 5 must be changed at the same time, but in the processing apparatus of the present invention, each roll 3, 4, , 5 are formed separately, it is only necessary to change the rolling roll 3. In any case, according to the processing apparatus of the present invention, it is only necessary to change the rolls that need to be changed, so the roll cost can be reduced. Furthermore, the rolling roll 3, which is prone to wear, can be made of a material that has better wear resistance than the materials that make up the other rolls 4 and 5, and in this way, the life of the unit roll can be improved. , the frequency of unit roll replacement can be reduced, thereby greatly reducing the effort required to replace the unit roll.

Furthermore, since the feed roll 4 and the guide roll 5 are made of hard urethane rubber as described above, their hardness is lower than that of the metal tube 7, and the feed can be fed without damaging the outer peripheral surface of the metal tube 7. can be applied. In particular, the second
When forming grooves with the rolling rolls 3 as shown in Figures b, c, and d, if the guide rolls 5 are made of hard urethane rubber, feed can be applied without crushing or deforming the grooves. Therefore, it is necessary to finish the outer peripheral surface of the copper metal tube 7 used in the heat exchanger to an order of 10 μm to several tens of μm, and in such cases, it is necessary to form the desired groove shape required in the design. It is extremely effective because it can be used to

In addition, if a drawing device is added after the device of the above embodiment, the outer diameter of the metal tube 7 can be corrected after giving a predetermined shape to the inner and outer surfaces of the metal tube 7, and the outer diameter can be made uniform. Of course, a metal tube can be obtained.

As explained above, according to the apparatus for processing the inner and outer surfaces of a metal tube according to the present invention, a rolling roll having an inclination angle with respect to the axis of the metal tube presses against the outer circumference of the metal tube while rotating to process a mandrel inside the metal tube. The metal tube is pressed against the metal tube, and feed rolls and guide rolls are provided on the front and rear sides of the rolling roll in the axial direction. The process of processing the metal tube into a diameter and the process of imparting a predetermined shape to the inner and outer surfaces of the metal tube can be performed simultaneously.

In addition, since the metal tube is strongly propelled by the rotational force of the feed roll located in front of the rolling roll, the reliable propulsion force creates a fine shape on the inner and outer surfaces of the metal tube. In addition, it is possible to feed the metal tube with sufficient accuracy, and its productivity can be greatly improved, and there is no need for particularly complicated pushing means or pulling means for propelling the metal tube. In addition, since the guide roll located behind the rolling roll guides the metal tube to a fixed position immediately after passing through the rolling roll, it prevents the metal tube from swinging out and reduces the diameter of the metal tube. A predetermined shape can be more accurately imparted to the inner and outer surfaces.
Furthermore, since the mill roll, feed roll, and guide roll are formed separately, if it is necessary to change any of the rolls, only that roll needs to be changed, thus reducing roll costs. It can be made inexpensive.

In particular, since the feed roll and guide roll are made of synthetic resin, they do not damage the outer circumferential surface of the metal tube, and when providing a predetermined shape such as a groove to the outer circumferential surface of the metal tube, the predetermined shape can be easily It has the advantage of being able to feed with a highly accurate shape without crushing or deforming it. Furthermore, the apparatus of the present invention can be widely used for manufacturing thin-walled tubes made of difficult-to-process materials such as titanium and Hastelloy.

[Brief explanation of drawings]

Fig. 1 is a schematic sectional view of the main parts showing an embodiment of the present invention, Fig. 2 is a schematic view showing the state of the outer circumferential surface of the rolling roll, and Fig. 3 shows the metal tube, feed roll, rolling roll, and guide. It is a schematic diagram showing a positional relationship with a roll. 2... Cylinder mechanism, 3... Roll roll, 4...
...Feed roll, 5...Guide roll, 6,2
0...Axis, 7...Metal tube, 8...Axis line, 13,1
9... Gear, 18... Drive source, 21, 22... Universal joint, 23... Intermediate shaft, 24...
...Mandrel, 25...Processing section.

Claims (1)

[Claims] 1. A rolling roll that is arranged on the outside of a metal tube at an angle of inclination with respect to the axis of the metal tube and that imparts a predetermined shape to the outer surface of the metal tube, and a rolling roll that is formed separately from the rolling roll. One set is constituted by a feed roll located on the front side in the axial direction of the roll, and a guide roll formed separately from the rolling roll and located on the rear side in the axial direction of the rolling roll. A plurality of sets of roll units are arranged, a drive mechanism that coaxially rotates the roll roll, feed roll, and guide roll in each set of roll units, and a drive mechanism that rotates the roll roll, feed roll, and guide roll in each set of roll units with the metal. a pressing mechanism for press-contacting the outer surface of the tube; and a processed portion having an outer circumferential surface formed into a predetermined shape, the processed portion being positioned inside the metal tube at a position corresponding to the rolling roll of each roll unit. An apparatus for processing the inner and outer surfaces of a metal tube, comprising a mandrel for imparting a predetermined shape to the inner surface of the metal tube, and wherein the feed roll and the guide roll are both made of synthetic resin.