US3574917A

US3574917A - Machine for assembling the core of heat exchanger

Info

Publication number: US3574917A
Application number: US749206A
Authority: US
Inventors: Katsuji Miyazaki
Original assignee: Toyo Radiator Co Ltd
Current assignee: Toyo Radiator Co Ltd
Priority date: 1968-07-31
Filing date: 1968-07-31
Publication date: 1971-04-13
Anticipated expiration: 1988-04-13

Abstract

A machine for automatically inserting a plurality of metal tubes one by one into series of openings formed through a plurality of metal plates which are arranged in parallel to each other. The insertion of the metal tubes is effected by a pneumatically operated pushrod. After insertion of one metal tube into a series of openings formed through the metal plates in alignment, the machine is automatically operable to shift the pushrod into register with a second series of openings next to the series of the openings which have been pierced through by the abovementioned metal tube. The retracting movement of the pushrod causes the supply of a new metal tube to the machine. Then the pushrod thrusts a second metal tube into the next series of the openings of the metal plates. Thus a plurality of metal plates are interwoven by a plurality of metal tubes to form the core of a heat exchanger of plate fin type.

Description

2,410,140 10 /1946 Young ite States Patent Inventor Katsuji Miyazaki Tokyo, Japan Appl. No. 749,206

Filed July 31, 1968 Patented Apr. 13, 1971 Assignee The Toyo Radiator Company, Limited Tokyo, Japan MACHINE FOR ASSEMBLING THE CORE OF HEAT EXCHAN GER IIL 2,481,490 9/1949 Bennettetal ABSTRACT: A machine for automatically inserting a plurality of metal tubes one by one into series of openings formed through a plurality of metal plates which are arranged in parallel to each other. The insertion of the metal tubes is effected by a pneumatically operated pushrod. After insertion of one metal tube into a series of openings formed through the metal plates in alignment, the machine is automatically operable to shift the pushrod into register with a second series of openings next to the series of the openings which have been pierced through by the above-mentioned metal tube. The retracting movement of the pushrod causes the supply of a new metal tube to the machine. Then the pushrod thrusts a second metal tube into the next series of the openings of the metal plates. Thus a plurality of metal plates are interwoven by a plurality of metal tubes to form the core of a heat exchanger of plate fin type.

Patented April 13, 1971 3 Sheets-Sheet 1 FIGQI" INVENTOR KA T5041. MIYAZAKI 4M4? ATTORNEY FIG.2

Patented April 13, 1971 3 Sheets-Sheet 5 INVENTOR KATSUJI NHYAZAKI ATTORNEY MACHINE FOR TI-[E CORE OF HEAT EXCHANGER This invention relates to a machine for assembling the core of a heat exchanger. More particularly, this invention relates to a machine for automatically inserting metal tubes sequentially into series of openings formed through a plurality of metal plates in alignment so that the radiator fins of the metal plates are interwoven by the water pipes of the metal tubes to form the core of a heat exchanger.

The present invention has for its object to provide an arrangement for thrusting a metal tube into a series of openings formed through a plurality of metal plates in alignment, charging the machine with a new metal tube while stepping tube-thrusting means into register with a second series of openings. Said arrangement is characterized by a tube guide which is adapted to guide and support the metal 'tube during its insertion into the metal plates, a pneumatically operated pushrod for thrusting the metal tube, a carriage for supporting said tube guide and pushrod, said carriage being displaceable in a direction perpendicular to the axis of said tube guide and pushrod, means for charging said tube guide with a new metal tube synchronously with the movement of said pushrod, and means for stepping said carriage so as to position said tube guide into register with the opening of the metal plate to be pierced through by a second metal tube.

One arrangement of a machine of the invention will now be described by way of example, reference being made to the accompanying drawings, in which:

FIG. 1 is a plan view of the machine;

FIG. 2 is a front elevation of the machine of FIG. 1;

FIG. 3 is a side elevation of the machine of FIG. 1;

FIG. 4 shows an enlarged cross section of a joint guide, which section being in the approximate plane of 4-4 of FIG. 9;

FIG. 5 shows an enlarged cross section of the tube guide in the approximate plane of 5-5 of FIG. 9;

FIG. 6 is a perspective view showing one metal tube in the position inserting into the metal plates;

FIG. 7 is a fragmentary sectional view of the metal plates and the metal tubes showing diagrammatically their relative position during the insertion of one metal tube;

FIG. 8 is an enlarged elevational view of a tube supplying device; and

FIG. 9 is an enlarged fragmentary sectional view of the tube supplying device along the line 99 of FIG. 8.

In the drawings, reference numeral 11 is applied to an elongated support member on which a tube guide 12, a piston guide 13 and an air cylinder 14 are mounted longitudinally therealong. The support member 11 is carried by a carriage 15 which is displaceable along guides 16 in a direction perpendicular to the axis of the tube guide 12, piston guide 13 and cylinder 14. A pair of spaced-apart bearing frames 17 which are coupled to each other by transverse frames 18, serves to support the guide 16. For its traverse along guides 16, the carriage 15 bears a nut, integral therewith, engaging a threaded portion of a drive shaft 19 joumaled in the bearing frames 17. The

frames

17 and 18 are integrally set on a platform 20 by means of four parallel columns 21 fixed to and rising vertically from the platform 20 so that a rigid frame structure is formed therewith.

Mounted on the platform 20 is a motor 22 having a reduction gear for producing an output of l revolution in a predetermined direction when an input signal is supplied thereto. This output of the motor 22 is transmitted to the drive shaft 19 so that the latter will make I complete revolution upon each supply of the input signal to the motor 22. To that end, the output shaft of the reduction gear of the motor 22 is provided with a pair of driving gears 23, each forming a part of trains of gearing, i.e., an outer gear train and an inner gear train. The outer gear train includes

wheels

23, 24 and 25. The inner gear train has

wheels

23, 26, 27 and 28. These gear trains consists of wheels of same gear ratio and are rotatably joumaled to a frame member 29 of the machine, as shown in FIGS. 1 to 3. It should be noted that the outer gear train has one intermediate gear, while the inner gear train has two. Thus the direction of rotation of the last wheel in each gear train is opposite to the other. Thus, when the driving gears 23 rotate in the direction of the arrow in FIG. 2, the last wheel 25 of the outer gear train will rotate in the same direction to the arrow, while the last wheel 28 of the inner gear grain will be counter to the arrow. The driving shaft 19 is splined at 30 on which a toothed wheel 31 is mounted in such a manner that the latter is rotatable with the former but is slidable therealong. The wheel 31 of the driving shaft 19 is selectively engaged with either of the

last wheels

25 or 28 by means of the operation of a lever 32 which engages at an end thereof with the boss of the wheel 31 and is pivotably carried by a bracket 33 secured to the machine frame. The operation of the lever 32 may be effected by a pneumatic device which utilizes the same source of compressed air to be supplied to the cylinder 14. The pneumatic device consists of a cylinder 34 and a piston 35, which cylinder is pivoted at one end to a bracket 36 secured to the machine frame. The outer end of the piston 35 is linked to the other end of the lever 32. Thus, the piston 35 drives the lever 32 to operate the engagement and disengagement of the wheel 31 with and from either of the

wheels

25 and 28.

Thus, when the wheel 31 is disengaged from the wheel 25 and is meshed with the wheel 28, and vice versa, the direction of rotation of the drive shaft 19 will be reversed, resulting in the change of the travelling direction of the carriage 15.

Secured rigidly to and projecting vertically downward from the center of the underside of the platform 20 is a sleeve 37 which is internally threaded at 38 to engage with a threaded portion of an upright shaft 39 rotatably supported on a base 40 by means of a suitable thrust bearing 41. The platform 20 has further four parallel posts 42, which posts may be extensions of the columns 21, respectively. The posts 42 extend vertically downward from the underside of the platform 20 and are received slidably by cylindrical poles 43 which stand on the base 40, respectively.

The upright shaft 39 has at the lower end portion thereof a worm wheel 44 which engages with a worm 45. Provided on the base 40 is an electric motor 46 for driving the worm 45 and worm wheel 44 which cause the platform 20 to move upwardly or downwardly corresponding to the direction of rotation of the motor 46.

The cylinder 14 on the support 11 is supplied with compressed air and drives a piston 47 reciprocally. The admission and exhaust of compressed air, for each end of the cylinder 14, may be controlled by an electromagnetic valve 48 which has an airhose 49 for communication with a source of compressed air (not shown) and is adapted to discharge its exhaust through a pipe 50.

The forward end of the piston 47 is coupled with an end of a pushrod 51 by means of a joint 52. There is formed a passage 53 for the joint 52 in the piston guide 13. The configuration of the passage 53 is especially shown in FIG. 4. The passage 53 is in alignment with a passage 54 which is formed throughout the length of the tube guide 12. Thus, the forward stroke of the piston 47 works to advance the joint 52 along the passage 53 and in turn drives the pushrod 51 forwards through the passage 54. Thus, when an metal tube 55 is charged in the tube guide 12, the tube 55 will be forced out from the forward end of the guide 12. The tube guide 12 acts to hold the tube 55 in alignment with a series of the openings 56 formed through a plurality of metal plates 57 during the insertion of the tube, see FIG. 6.

When the machine is operated to insert the metal tube 55 into the openings 56 of the metal plates 57, the plates must be firmly supported to keep the openings aligned in order to provide a straightway for receiving the tube. The support of such metal plates has not, however, been described nor shown since any conventional mechanism may be applied thereto.

The openings 56 may be formed by punching the plates 57 in accordance with the configuration of the metal tube 55 to be inserted. When a blank of metal plate is punched, it is preferably left a rim 58 in each of the openings 56, reducing the diameter of the respective opening. Thus, the diameter of the opening 56 is slightly smaller than that of the tube 55, see FIG. 7. When the tube 55 is thrusted into the opening 56, the former will act on the latter to yield and expand the diameter of the opening. Thus an intimate contact will be obtained between the tube 55 and the plate 57. After insertion of the metal tubes 55 through the aligned openings 56 of the metal plates 57, the plates will be interwoven to form the core of a heat exchanger. The metal tubes 55 are preferably coated with suitable soldering material; andafter the interweaving of the plates with the tubes, the produced core is subjected to an elevated temperature so that the plates and the tubes will be soldered to each other to improve their heat conductivity.

The machine of the invention may be operated automatically. A supply of metal tubes is held in a magazine 59 in which the tubesare arranged in a row. The magazine 59 includes a follower 60, wires 61, guide pulleys 62 and a weight 63. The follower 60 acts to bias the tubes 55 toward the tube guide 12, by the gravity of weight 63, see FIGS. 1 and 8. Thus the metal tubes 55 will be dropped one by one by gravity into the passageway 54 of the tube guide 12. The weight 63 serves also a balancer.

In order to avoid the failure of supply of the tube to the tube guide 12 or to avoid the imperfect loading of the tube in the passageway 54, the charging of the respective tube is synchronized with the reciprocal movement of the joint 47. As will be shown especially in FIGS. 8 and 9, a plate 64 is provided above the tube guide 12 by means of a fixture 65. The vertical portion of the fixture 65 has pins 66 which are adapted to engage with slots 67 formed in the plate 64, respectively. The slots 67 are inclined downwardly and rearwardly, to toward the direction of retracting movement of the piston 47. The rear end, or the end near to the piston guide 13 of the plate 64 is linked with an end of a rod 68. The rod 68 extends rearwardly and reaches its rear end to a position near the end of the backward stroke of the joint 52. Provided at the rear end of the rod 68 is a block 69 which is adapted to engage with the backside of the joint 52 a little before the joint reaches the end of its backward move. Thus, the last backward move of the joint 52 will cause to pull the plate 64 rearwardly, resulting in lowering the latter along the slots 67. FIG. 9 shows, in solid lines, the joint 52 has reached the end of its backward move, where the plate 64 is lowered. The joint 52 has at the upper front side thereof a cam surface 70. When the joint 52 has approached the end of its forward stroke, the cam surface 70 of the joint 52 engages with an inclined surface 71 of the plate 64. Thus, the last forward move of the joint 52 causes to lift the plate 64 along the slots 67 of the latter to the position shown in chain and dotted lines in FIGS. 8 and 9, where the plate places out of the outlet of the magazine 59. When the plate 64 is raised, the tube at the left end in the row in the magazine 59 of FIG. 8 is forced out of the magazine by the weight-loaded follower 60 and is urged toward the vertical portion of fixture 65. When the pushrod 51 has retracted from the passageway 54 of the tube guide 12, the passageway will become empty and it will be ready for receiving a second tube therein. Thus, the second tube will be charged positively into the passageway 54 by the lowering movement of the plate 64 in the manner as described above.

The forward stroke of the pushrod 51 is controlled by a limit switch 72 provided at a position near the end of the forward stroke of the joint 52, which switch produces a signal for operating the electromagnetic valve 48. Thus, when one metal tube has inserted into the plates to an extent of a predetermined length, the joint 52 comes to a position to operate the limit switch 72. Then the limit switch 72 operates the valve 48 to change the direction of flow of compressed air for reversing the piston 47.

With the start of its retracting motion of the pushrod 51, a second signal is produced to drive the motor 22. Thus the carriage 15 is driven by the shaft 19 and slides along the guides 16. The shaft 19 has the lead of its thread equal to the distance between corresponding points in ad acent opening profiles of the metal plates so that the tube guide 12 will be registered with the openings of the metal plates adjacent to the openings which have been just pierced through by the metal tube.

When the tube guide 12 is registered with the new openings of the metal plates, a third signal is produced to operate the valve 48 for starting the forward stroke of the pushrod 51. This third signal may be produced by a suitable timer which is energized by the retracting movement of the joint 52.

Thus the carriage 15 steps after each insertion of one metal tube into a series of openings of the metal plates. When the carriage 15 has reached the end of its travel, it operates a

suitable switch

73 or 74 provided on the inner sides of the frames 17 to drive the motor 46. Then the motor 46 drives the shaft 39 for lowering or raising the platform 20 to the position where the tube guide 12 is registered in the height of the lower or upper row of the openings of the metal plates for starting next cycle of the insertion of the metal tubes in accordance with the operation and the control as described above.

Iclaim:

1. A machine for assembling the core of a heat exchanger comprising a tube guide for aligning a metal tube with a series of openings formed through a plurality of metal plates, a pushrod for thrusting the metal tube into the openings of the metal plates, means for driving said pushrod reciprocally, means for controlling the reciprocal movement of said pushrod; a carriage for supporting said tube guide and pushrod longitudinally therealong, motor means for moving said carriage in a direction perpendicular to the axis of movement of said pushrod, said motor means having means for automatically positioning said tube guide in register with the openings on said metal plates, second motor means for vertically moving said carriage, said second motor means having means for automatically positioning said tube guide to a predetermined position where said tube guide registers with a second series of openings above or under the first series of openings which have been pierced through by the metal tube, and a container means for holding metal tubes, said container means being adapted to controllably supply a new metal tube to said tube guide synchronously with the movement of said pushrod.

2. A machine for assembling the core of a heat exchanger as claimed in claims 1, wherein the pushrod and the piston rod are connected to each other by means of a joint member which serves to operate a valve for controlling the supply of driving medium to the cylinder of said piston.

3. A machine for assembling the core of a heat exchanger as claimed in claims 1 and 2, wherein the means for controlling the reciprocal movement of the pushrod includes electric switch means which are operated by the joint member for generating a signal for reversing the piston rod, a second signal for moving the carriage in a direction perpendicular to the axis of reciprocal movement of said piston rod and a third signal for starting next thrust of said pushrod after a predetermined time.

4. A machine for assembling the core of a heat exchanger as claimed in claims 1 and 3, wherein the first-mentioned motor means are controlled by the second signal.

5. A machine for assembling the core of a heat exchanger as claimed in claim 1, wherein the second-mentioned motor means are controlled by electric switches which are operated by the traverse of the carriage.

6 A machine for assembling the core of a heat exchanger as claimed in claims 1 and 2, wherein the container means for holding metal tubes includes a tube presser which is driven by the joint member upwardly when said joint member has attained the end of its forward stroke and downwardly when said joint member effects its last backward move during which a new metal tube is pressed by said tube presser to charge into the tube guide.

Claims

6. A machine for assembling the core of a heat exchanger as claimed in claims 1 and 2, wherein the container means for holding metal tubes includes a tube presser which is driven by the joint member upwardly when said joint member has attained the end of its forward stroke and downwardly when said joint member effects its last backward move during which a new metal tube is pressed by said tube presser to charge into the tube guide.