JPS6027529Y2 - Tube expansion device for heat exchanger - Google Patents

Description

[Detailed description of the invention] This invention provides an appropriate amount of pressing force and rotational torque to the expander, allowing tube expansion for heat exchangers to be performed without creating dents or scratches on the inner surface of the heat exchanger tube. Open the device.

In shell-type heat exchangers and the like, heat exchanger tubes are expanded and expanded to provide a mechanically strong structure at the joint between the end of the heat exchanger tube and the tube plate.

As shown in FIG. 6, this type of conventional tube expanding device rotates and advances an expander mandrel 15 connected to the expander drive shaft 7 via a coupling 19', thereby fixing the expander at the tip. The most common method is to rotate the tool 16, for example, an expander, at the same time as it is pushed open, so that it does not roll against the inner surface of the heat exchanger tube, thereby pushing and expanding the skeleton.

In this case, the coupling 19' for connecting the drive shaft 7 and the expander mandrel 15 fixes the expander drive shaft 7, which is integral with the rotating shaft 4, with the set port 36, and the expander mandrel 15 is also fixed in the same way. Since the structure is fixed by a set bolt 36 to the
8wn/5ec) is applied directly to the expander mandrel 15 through the supporting substrate 13 and the coupling 19', so an excessive pushing force is applied to the expander roller 16 depending on the speed at which the mandrel 15 is inserted.
The roller 16 becomes indented on the inner surface of the heat transfer tube t, so that the roller 16 stops rotating, and the inner surface may not be expanded uniformly.

Further, when the expander mandrel 15 is pulled out simultaneously with the reverse rotation after the pipe expansion is completed, a phenomenon occurs in which the expander mandrel 15 is pulled out faster by the hydraulic cylinder 14 than when the expander mandrel 15 is pulled back in the reverse rotation, and as a result, the roller 1
There was also the problem that the inner surface of the heat exchanger tube was pulled in 6, causing scratches on the inner surface of the tube.

Focusing on the fact that conventional tube expansion devices have the disadvantage of causing dents and scratches, the present invention has been developed to reliably and easily eliminate these defects by using a coupling with a simple structure. The present invention has come to provide a pipe expansion device that is capable of expanding pipes, and in particular, a drive joint member that is fitted concentrically to and integrated with the expander drive shaft, and a drive joint member that is fitted concentrically and integrated with the expander mandrel, and the joint member that is fitted concentrically and integrated with the expander mandrel. A driven joint member that is slidably engaged with the member within a predetermined axial length to transmit rotational and forward/backward movements, and a driven joint member that is inserted between opposing walls of both joint members, The coupling is characterized by comprising a spring that applies elastic force in a direction of separation to both joint members.

The specific content of the present invention having the above features will be described in detail below with reference to an embodiment of the accompanying drawings.

FIG. 1 is a schematic perspective view of an automatic settle machine using the device of the present invention, in which the workpiece W to be expanded is a shell end tube condenser, and the workpiece W is transferred to a hydraulic cylinder for horizontal movement. The workpiece W is placed on a transfer table T that can be moved two-dimensionally by a hydraulic cylinder S1 and a hydraulic cylinder S2 for vertical movement.A motor M is installed on both sides of the workpiece W facing the tube sheets P and P to move the workpiece W over the main body bed B. The tube expansion head H, which is mounted on a slide pedestal that slides symmetrically, has its machining tip facing the tube sheets P and P, respectively.

This automatic settle machine has a pair of tube expansion heads H or both tube plates P.
, multi-stage and multi-row heat exchanger tubes 1, 1...
The pipe ends are expanded in sequence.

The tube expansion heads H, H are equipped with one or more tube expansion devices according to the present invention, and the basic structure of the tube expansion device will be explained with reference to FIGS. 2 to 5. , To expand the tube The tube body 1 fixed to the head H extends horizontally parallel to the heat transfer tube t, and the slide shaft 2 and the transmission shaft 3, which are hollow round shafts, are housed in the tube back and forth, and the slide shaft 2 is inserted into the tube. The main body 1 is slidable in the axial direction, and the transmission shaft 3 is rotatable at the rear of the cylindrical main body 1 via radial bearings 32,32.

A rotary shaft 4 is inserted concentrically through the slide shaft 2 and the transmission shaft 3 via a thrust radial bearing 31, 31 and a key 5, and the rotary shaft 4 is inserted into the slide shaft 2 and the transmission shaft 3 concentrically. It is rotatable and slidable in the direction of the transmission shaft 3 through the interposition of a key 5.

The rotating shaft 4 is formed from a hollow shaft, and has a flange 6 at the tip, and an expander drive shaft 7 that is loosely inserted concentrically into the hollow part. 7 is fixedly integrated with a stopper member 8 that is in contact with the rear end of the rotating shaft 4 by means such as brazing, and the rear end of the drive shaft 7 is fixed to the rotating shaft 4, and the driving The tip of the shaft 7 protrudes from the tip of the rotating shaft 4 in a cantilevered manner.

The transmission shaft 3 is fitted with a boot 9 at its rear end protruding from the cylinder body 1, and the drive pulley 11 of the motor 10 and the transmission belt 12 are connected to the pulley 9 fixed to the cylinder body 1.
They are connected in a power-conducting manner via.

With the above-described structure, when the motor 1° is energized, the transmission shaft 3 rotates within the cylinder body 1, and this rotational force is transmitted to the rotation shaft 4, allowing it to rotate smoothly.

On the other hand, the slide shaft 2 has a substrate 13 fitted onto the outer periphery of the tip portion protruding from the cylinder body 1, and the substrate 13 is orthogonal to the slide shaft 2 and integrated therewith.

The base plate 13 is engaged with a rod of a hydraulic cylinder 14 fixed to the tube expansion head H parallel to the axis of the cylinder body 1, and by moving the rod of the hydraulic cylinder 14 forward and backward, the base plate 13 and the slide shaft are engaged with each other. 2 can be moved forward and backward.

It goes without saying that the rotary shaft 4 is subjected to a complex movement of rotation and forward/backward movements.In this case, the rear end of the expander drive shaft 7 is coaxially attached to the rotary shaft 4, but is placed in a free state, so even if there is a slight misalignment between the workpiece W and the heat transfer tube t, the flexibility of the expander drive shaft 7 ensures smooth alignment. Corrective movement is now being threatened.

The expander drive shaft 7 has a coupling 19 fitted to its tip, and the expander mandrel 15 is coaxially connected to the expander mandrel 15 through the coupling 19. Expander jig 16
In order to concentrically hold the expander jig 16 that engages with the expander mandrel 15, the expander mandrel 15 is engaged with the expander mandrel 15 to expand the heat transfer tube t. By connecting the expander supporting plate 23 loosely fitted to the mandrel 15 and the substrate 13 by a holding rod 24 having a return spring 25, the expander is formed so that it can be moved into and out of parallel to the substrate 13. The jig 16 is flexibly supported on the expander support plate 23 so that the expander handle 15 and the expander jig 16 are engaged concentrically.

The expander jig 16 is a well-known pipe expansion jig consisting of a roller 17 and a roller holder 18, and the truncated conical roller 17, which is long in the direction of the rotational axis, is moved around the rotation center of the expander mandrel 15. It has a structure that has multiple units.

In the pipe expansion device having the structure described above, the coupling 19 for coaxially connecting the expander drive shaft 7 and the expander mandrel 15 is a member that is a feature of the present invention, and the structure is shown in FIGS. 3 and 4. To explain, the coupling 19 includes a driving side joint member 20, a driven side joint member 21, and a spring 26 as main members, and further has an outer cylinder 22.

The drive-side joint member 20 is formed into a stepped tube having a small-diameter tube protruding from its tip, and is connected to the expander drive shaft 7 by fitting the expander drive shaft 7 into a shaft hole provided through the center. are designed to connect concentrically.

Insert the joint member 20 into the outer cylinder 22 and set the set bolt 35.
．． 35, the outer cylinder 22. The joint member 20 and the expander drive shaft 7 are coaxially fixed and integrated without any sliding movement in the axial direction or circumferential direction.

On the other hand, the driven side joint member 21 is formed into a cylindrical body having a flange having the same diameter as the joint member 20 on the rear side facing the drive side joint member 20, and is inserted into the stepped hole of the outer cylinder 22. By doing so, it is possible to slide in the axial direction by a length 1 shown in the third figure.

This driven side joint member 21 is inserted into the outer cylinder 22 in such a way that the key 28 that is engaged in the key hole is inserted into the key groove 27 cut in the inner wall of the outer cylinder 22 parallel to the axis. Although it is possible to slide by a predetermined length 1 in the axial direction as described above, sliding in the axial circumferential direction with respect to the outer cylinder 22 is not affected at all.

The driven side joint member 21 has a square hole at the center of the axis on the front side, and the hole receiver that penetrates this square hole has a through hole 30 in the peripheral wall, and the pole 29 is fitted into the hole 30. There is.

On the other hand, the expander mandrel 15 has a base 33 formed into a square column corresponding to the square hole, and a hole groove 34 for partially receiving the ball 29 is recessed in the square column.

With this structure, by inserting the base 33 of the expander mandrel 15 into the square hole of the driven joint member 21, it is possible to secure the expander mandrel 15 without any sliding in the axial direction. 33, when the driven side joint member 21 is slightly pushed into the outer cylinder 22, the hole 29 moves in the radial direction along the tapered wall surface formed on the outer periphery 22. It can be easily inserted into the hole.

When the insertion is completed in this way, the driven side joint member 21 returns to its original position by the elasticity of the spring 26, which will be described later, so that the pole 29 is in a state straddling between the through hole 30 and the hole groove 34. Therefore, the expander mandrel 15 does not come out and is coaxially engaged with the joint member 21.

A spring 26 is further interposed in the inner space of the outer cylinder 22 into which the above-mentioned joint members 20 and 21 are fitted. 26,
It is inserted between the opposing wall portions of both the joint members 20.21 to apply elastic force in the direction of separating the joint members 200.21.

Therefore, the driven side joint member 21 is placed in the state where it protrudes most forward as shown in FIG. It is important to be firmly integrated with the

In addition, in FIG. 3, the coupling 19 having the above-mentioned structure is obtained by fitting the driven side joint member 21 into the hole of the outer cylinder 22 from the right side, then fitting the spring 26, and then fitting the driving side joint member 20. The assembly is completed by tightening and fixing the set bolts 35 and 35.

The procedure for performing tube expansion using the tube expansion device configured as described above will be described below.

Heat exchanger tube t for tube expansion processing by expander jig 16
After positioning the tube expansion head H so that it faces the tube in a state where it is approximately centered L7, the motor 10 is urged in the normal rotation direction.

The rotational force of the motor 10 at this time is transmitted to the transmission shaft 3 via the drive pulley 11, transmission belt 12, and pulley 9, and then
The rotation is transmitted to the rotating shaft 4 whose rotational relationship is regulated by the key 5.

This rotation of the rotation shaft 4 transmits rotational force to the coupling 19, and the expander drive shaft 7 and the expander mandrel 15 work together to rotate the expander jig 16 at the tip of the rotation waist at a predetermined rotation speed.

Next, when the hydraulic cylinder 14 is actuated to move the rod forward, the slide shaft 2 moves forward, so that the rotary shaft 4, which rotates in a mating relationship with the slide shaft 2, moves forward.

The forward movement of the rotating shaft 4 is transmitted to the expander drive shaft 7 via the stopper member 8, and further transmitted to the expander mandrel 15 via the coupling 19.
The expander jig 16 at the tip of the mandrel 15 gradually approaches the heat transfer tube t, and expander roller 17. t
; and the tapered tip portion of the extract bank mandrel 15 is inserted into the heat transfer tube t.

Here, even if there is a slight deviation between the axis of the expander mandrel 15 and the tube center of the heat transfer tube t, the expander drive shaft 7 has flexibility as described above, so that an unreasonable load will not occur. Smooth insertion is possible without any friction.

When the rod of the hydraulic cylinder 14 further moves forward, the collar 37 hits the tube plate P and the expander support plate 23 stops moving forward, compressing the return spring 25 and
3. The slide shaft 2, the rotation shaft 4, the expand drive shaft 7, and the expander mandrel 15 move forward.

As a result, the tapered portion of the expander mandrel 15 pushes and expands the rollers 17, 17 from the inside, and while the heat transfer tubes are pasted on the inner surfaces of the outer peripheries of the rollers 17, 17, the rotation of the expander mandrel 15 is caused by the rollers 17, 17. Since the tube 17 is rotated, the tube is expanded.

In this case, the end of tube expansion is easily detected when the current value of the motor 10 exceeds a predetermined value.

When the pipe expansion is completed in this way, the hydraulic cylinder 14 is operated in reverse to move the rod backward, and at the same time, the motor 10
and rotate the expander mandrel 15 in the opposite direction.

As the expander mandrel 15 retreats, its tapered end is pulled out from the roller 17, and as the mandrel 15 retreats further, the expander support plate 2
3 also starts to retreat, and the jig 16 set therein is pulled out from the heat transfer tube t, thus completing one cycle of the tube expansion process.

In performing the above pipe expansion process, the device of the present invention inserts a spring 26 into the coupling 19 to provide a cushioning function between the expander drive shaft 7 and the expander mandrel 15, so that 120 kg / clr
A large push-in force is not directly applied to the expander mandrel 15 due to the contraction of the spring 26, and only the set elasticity of the spring 26, for example, about 20 kp/cJ, is applied to the mandrel 15.

On the other hand, when the expander mandrel 15 is pulled out after the pipe expansion is completed, no tensile force is applied to the expander mandrel 15 until the contracted spring 26 returns to its original state.
7 and 17 are separated from the inner surface of the tube, and the expander mandrel 15 is in a state where it can be easily removed.

Therefore, in either case of pushing in or pulling out the expander mandrel 15, if the hydraulic pressure is excessively applied by the rollers 17. This eliminates the occurrence of dents, etc., and enables uniform pipe expansion.

As is clear from the detailed description above, the tube expanding device of the present invention engages the front end with the expander jig 16 and expands the expander.
An expander mandrel 15 for rotating and expanding the expander mandrel 6 and an expander drive shaft 7 whose rotation and forward/backward movements are provided by a drive source are coaxially connected by a coupling 19. A drive-side joint member 20 that is concentrically fitted and integrated with the expander drive shaft 7; and a drive-side joint member 20 that is concentrically fitted and integrated with the expander mandrel 15.
a driven side joint member 21 that is slidably engaged within a predetermined axial length range to transmit rotation and forward/backward movement;
Since the spring 26 is inserted between the opposing walls of the circumferential joint members 20 and 21 and applies elastic force in the direction of separation to the circumferential joint members 20 and 21, the expander drive shaft 7 and the expander The cushioning function of the spring 26 against the axial pushing and pulling force acts on the connecting portion with the mandrel 15, eliminating the problem of excessive force being applied directly to the expander jig 16. Therefore, the inconvenience of scratches and dents on the inner surface of the heat exchanger tube is eliminated, and an excellent effect of ensuring uniform tube expansion is achieved.

Furthermore, since the spring 26 absorbs the difference between the mechanical feed by hydraulic pressure or the like and the feed by the expander jig 16, it does not apply excessive force to the settle machine and eliminates unnecessary play. It also has the advantage that it can be disposed of and that the tube expansion device can operate stably and has a long life.

[Brief explanation of the drawing]

1 to 5 respectively show aspects of examples of the device of the present invention, FIG. 1 is a schematic perspective view of an automatic settle machine according to the implementation of the device of the present invention, and FIG. 2 is a sectional view of the main part of the device of the present invention. 3 is an enlarged sectional view of the coupling in FIG. 2, FIG. 4 is a sectional view taken along line A-A in FIG. 3, and FIG. 5 is a base of the expander mandrel in FIG. 2. FIG. 6 is a perspective view of the main part of a conventional tube expansion device. 7... Expansion drive shaft, 15...
Expander mandrel, 16... Expansion jig, 19... Coupling, 20...
... Drive side joint member, 21 ... Driven side joint member, 26 ... Splash.

Claims (1)

[Scope of utility model registration request] The front end portion is engaged with the expander jig 16 and the jig 16 is
Expander mandrel 1 for rotating and expanding
5 and an expander drive shaft 7 whose rotation and forward/backward circular motion is given by a drive source are coaxially connected by a coupling 19, and the coupling 19 is fitted concentrically to the expander drive shaft 7. The drive-side joint member 20 is integrally fitted with the expander mandrel 15, and the expander mandrel 15 is fitted concentrically with the expander mandrel 15 to be integrated with the drive-side joint member 20, and is slidably engaged with the drive-side joint member 20 within a predetermined axial length. inserted between the opposing wall portions of the driven side joint member 21 to which rotational and forward/backward movements are transmitted and the circumferential joint member 20.21,
A tube expansion device for a heat exchanger, characterized in that it is formed from a spring 26 that applies an elastic force in a direction of separation to the circumferential joint members 20 and 21.