Method of machining a flat harness using a punching machine

Abstract

A flat harness is machined by providing a punching machine that includes a first punching device and a second device, and forming different types of hole portions in the shape on the insulating portion of the flat harness in a die cutting process by using the first punching device and the second punching device.

Claims

1. A method of machining a flat harness, the flat harness including at least three conductor portions, which extend in a longitudinal direction and are aligned in parallel, and insulating portions arranged between adjacent conductor portions of the at least three conductor portions, the method comprising: providing a punching machine that includes a first punching device and a second punching device that are separately provided and independently controllable, the first and second punching devices each including a punch and a die; punching a first hole portion on each of the insulating portions arranged between the adjacent conductor portions of the at least three conductor portions of the flat harness in a die cutting process by moving one of the punch and the die of the first punching device in a first direction perpendicular to the longitudinal direction; and punching a second hole portion on each of the insulating portions arranged between the adjacent conductor portions of the at least three conductor portions of the flat harness in the die cutting process by moving one of the punch and the die of the second punching device in the first direction; wherein the method of punching the flat harness is performed by moving at least one of the second punching device and the flat harness in the longitudinal direction and relative to each other between the punching of each first hole portion and the punching of each second hole portion respectively by a predetermined distance in the longitudinal direction, said predetermined distance being variable and selected such that the second punching device is at a position relative to the flat harness so that the punch of the second punching device is aligned to overlap or abut each respective first hole portion, wherein the punching of each second hole portion forms a third hole portion on each of the insulating portions, each third hole portion having a length larger than that of the respective first hole portion on each respective insulating portion of the flat harness, and wherein the punching of the first hole portion on one of the insulating portions is displaced by a level difference in the longitudinal direction from the punching of the first hole portion on another one of the insulating portions such that a distal end of the third hole portion formed by the first hole portion on said one of said insulating portions is displaced in the longitudinal direction relative to a distal end of the third hole portion formed on said another one of the insulating portions.

2. The method according to claim 1, wherein for punching one of the first hole portions, the punch of the first punching device is a first punch, and the first punching device further comprises a second punch that is differently shaped relative to the first punch; and wherein the punching of the one first hole portion is performed by the first punch of the first punching device, and further comprising punching a fourth hole portion using the second punch of the first punching device, wherein the punching of the one first hole portion and the punching of the fourth hole portion are performed simultaneously by the first punching device in the die cutting process.

3. The method according to claim 2, wherein the predetermined distance is selected such that the position of the second punching device is selected so that the punch of the second punching device is aligned to overlap the fourth hole portion to form the third hole portion.

4. The method according to claim 3, wherein a width of the fourth hole portion is less than or equal to a width of the corresponding second hole portion.

5. The method according to claim 2, wherein the one first hole portion has a near end distal to the fourth hole portion and a far end proximal to the fourth hole portion, and wherein the fourth hole portion is spaced from the far end of the one first hole portion, and a distance from the far end of the one first hole portion to a far end of the fourth hole portion is less than or equal to a length of the punch of the second punching die; whereby the fourth hole portion is eliminated as a result of punching of the corresponding second hole portion.

6. The method according to claim 1, wherein the position of the second punching device is selected so that the punch of the second punching device is aligned to overlap the respective first hole portion.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The above objects and advantages of the present invention will become more apparent by describing in detail preferred exemplary embodiments thereof with reference to the accompanying drawings, wherein:

(2) FIG. 1 is a plan view showing a flat harness manufactured by a flat harness machining method according to a first embodiment of the present invention;

(3) FIG. 2 is a plan view showing an intermediate machining state of the flat harness manufactured by the flat harness machining method;

(4) FIG. 3 is a plan view showing a flat harness manufactured by the flat harness machining method according to a second embodiment of the present invention;

(5) FIG. 4 is a plan view showing a flat harness manufactured by the flat harness machining method according to a third embodiment of the present invention;

(6) FIG. 5 is a principal perspective view showing a mode of a punching machine used in the flat harness machining method;

(7) FIG. 6 is a longitudinal sectional view showing a mode of a punching machine used in a flat harness machining method in the prior art;

(8) FIG. 7 is a plan view showing a principal portion of the flat harness formed by the flat harness machining method in the prior art;

(9) FIG. 8 is a perspective view showing a mode of a flat harness fitting method in the prior art;

(10) FIG. 9 is a plan view showing a mode of a flat harness connector manufacturing method in the prior art;

(11) FIG. 10 is a plan view showing the flat harness connector in the prior art; and

(12) FIG. 11 is a perspective view showing a mode of the flat harness in the prior art.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(13) FIG. 1 to FIG. 4 show a flat harness machining method according to the exemplary embodiments of the present invention.

(14) In FIG. 1, in a flat harness 1.sub.1, a slit-like longer first hole portion 4 (4.sub.1,4.sub.2) and a rectangular shorter second hole portion 5 (5.sub.1,5.sub.2) are provided in an insulating coupling plate portion (insulating portion) 3 in each row between conductor portions 2 in parallel in the harness longitudinal direction respectively. Also, a circular third hole portion 6 is provided between the longer hole portion 4.sub.1 and the shorter hole portion 5.sub.1 in vicinity of the longer hole portion 4.sub.1 in the first row. The conductor portions 2 are covered with an insulating coating 7 made of a synthetic resin or a synthetic rubber, and respective hole portions 4 to 6 are provided to the coupling plate portion 3 that couples integrally respective insulating coatings 7.

(15) When the conductor portions 2 are press-fitted into the press-fitting terminals (not shown), the ribs of the setting jig of the press-fitting unit (not shown) are engaged with the longer hole portions 4 to position the flat harness 1.sub.1. Also, the circular hole portion 6 is used to position the flat harness 1.sub.1 by inserting the positioning pin of the press-fitting unit when the flat harness 1.sub.1 is set to the press-fitting unit. Also, the shorter hole portions 5 are used to position the flat harness 1.sub.1 by inserting the projections (not shown) of the vehicle, the onboard equipment, or the like when the flat harness 1.sub.1 is provided to the vehicle, the onboard equipment, or the like. In this case, the press-fitting pieces of one or plural press-fitting terminals may be passed through the longer hole portions 4 and the shorter hole portions 5.

(16) The longer hole portion 4 is formed by a longitudinal longer punch 9 and a device 12 of a punching machine 8 shown in FIG.5. The circular hole portion 6 is formed by a circular (circular cylinder) punch 10 and a circular device 13 in FIG.5. The shorter hole portion 5 is formed by a rectangular shorter punch 11 and a device 14 in FIG.5. Base plate portions 15, 16 of the dies 12, 14, which are used to process the longer and shorter hole portions 4, 5, may be formed to extend integrally in the longitudinal direction, as indicated with a chain line 17 in FIG.5. It is preferable that the base plate portions 15, 16 should be moved back and forth independently in the longitudinal direction of the harness.

(17) In the punching machine 8 in FIG. 5, the longer punch 9 and the circular punch 10 are provided integrally to the same head 18, and the shorter punch 11 is provided to another head 19. In the first head 18, the circular punch 10 may be moved vertically independently from the longer punch 9.

(18) The longer punch 9 and the circular punch 10 and their corresponding dies 12, 13 constitute a first punching device 21. The shorter punch 11 and the corresponding die 14 constitute a second punching device 22. When respective dice 12 to 14 are formed in the same base plate portion 17, as indicated with a chain line in FIG. 5, the longer punch 9, the circular punch 10, and the common base plate portion 17 constitute the first punching device 21, and the shorter punch 11 and the common base plate portion 17 constitute a second punching device 22.

(19) In FIG.5, the punches 9 to 11 and the dies 12 to 14 are aligned in one row. In this case, the punches 9 to 11 and the dies 12 to 14 may be arranged in plural in parallel or almost parallel with each other in the alignment direction of the conductor portions 2 (displaced slightly in the longitudinal direction of the harness) to correspond to respective coupling plate portions 3 between the conductor portions of the flat harness 1.sub.1. It would be preferable to do so because plural holes 4 to 6 having the same shapes can be opened simultaneously.

(20) For convenience of explanation, the flat harness 1.sub.1 having three conductor portions 2 is illustrated in FIG.1. Of course, the flat harness having four conductor portions 2 or more can be used. In such case, it is preferable that the punches 9 to 11 and the dies 12 to 14 should be arranged in positions that correspond to respective coupling plate portions 3. The shape of the conductor portion 2 is not limited to a circular section, and a rectangular shape, a flat type, or the like may be set appropriately as occasion demands.

(21) In FIG. 1, the longer hole portions 4 are formed to displace slightly in the longitudinal direction of the harness (to have a level difference L.sub.1) respectively, whereby it can be prevented that the flat harness 1.sub.1 is fitted to the setting jig in its reversed state. The longer hole portions 4 are formed to have the same length and width. The circular hole portion 6 is provided closely on one end (inner end) side of the longer hole portion 4.sub.1 in the first row in parallel with such longer hole portion 4.sub.1. An inner diameter of the circular hole portion 6 is set identically to or smaller than an inner width of the longer hole portion 4.sub.1. A distance from one end of the longer hole portion 4.sub.1 to one end of the circular hole portion 6 is set equal to or smaller than a length of the shorter hole portion 5.sub.1.

(22) When the longer hole portion 4 is formed by one longer punch 9 (FIG.5) and the die 12, the longer punch 9 and the die 12 are moved right and left and backward and forward (the longitudinal direction and the width direction of the harness) by a driving means (not shown). The longer hole portion 4.sub.1 and the circular hole portion 6 in the first row are formed simultaneously with one stroke of the head 18 (FIG.5), and then the longer hole portion 4.sub.2 in the second row can be formed by the longer punch 9 in a state that the circular punch 10 is lifted to be set free, for example. When a plurality of the punches 9 to 11 and the dies 12 to 14 are arranged in every row, the above procedure is not needed. Therefore, the longer hole portion 4 and the circular hole portion 6 in each row can be formed simultaneously with one stroke of the head 18.

(23) The shorter hole portions 5 are formed in parallel away from the longer hole portions 4 in the longitudinal direction of the harness in registration with them. The shorter hole portions 5 are formed to have the same size and shape, and are formed on a prolonged line of the longer hole portion 4 to have the same width dimension (dimension of the short side portion) as the longer hole portion 4.

(24) The shorter hole portions 5 in each row may be formed separately by moving one shorter punch 11 in FIG.5 in the width direction of the harness, or the shorter punch 11 and the die 14 may be arranged in each row and then the shorter hole portions 5 may be formed at the same time. The holes may be opened by not moving the punches 9 to 11 and the dies 12 to 14 but moving the flat harness 1 itself right and left and backward and forward.

(25) FIG. 2 and FIG. 3 show a mode in which longer secondary hole portions 20 are formed by forming the shorter hole portions 5 (5.sub.1, 5.sub.2) to be connected to or lapped over the longer hole portions 4 (4.sub.1,4.sub.2) of a flat harness 1.sub.2.

(26) First, as shown in FIG. 2, the longer hole portion 4 is formed in the coupling plate portion (insulating portion) 3 between the conductor portions 2 by the longer punch 9 and the device 12 in FIG. 5 while displacing little by little in the longitudinal direction, like the longer hole portion 41 in FIG. 1. Then, as shown in FIG. 3, the shorter hole portions 5 are formed on one end side of the longer hole portions 4 by the shorter punch 11 and the device 14 in FIG. 5.

(27) Because the shorter hole portion 51 is punched to overlap with the circular hole portion 6, the circular hole portion 6 adjacent to the longer hole portion 41 in the first row is eliminated. Since the circular positioning hole portion 6 is eliminated, such a situation can be eliminated that, for example, when a longer secondary hole portion 20.sub.1 (FIG. 3) is used to position at a time of the press-fitting, the worker mixes up such circular positioning hole portion 6 with other positioning hole portions 6 and is confused. In particular, since the above confusion is liable to occur when a positioning hole portion such as a rectangle (square or rectangle), or the like is provided instead of the circular hole portion 6, the advantage of eliminating the unnecessary hole portion is great.

(28) Also, since the shorter hole portion 5.sub.2 is punched to lap over one end portion of the longer hole portion 4.sub.2 in the second row, one end position of each of the rectangular shorter second hole portions 5.sub.1, 5.sub.2 can be aligned without displacement. Since the hole portions 4.sub.2, 5.sub.2 are formed to lap mutually, a length of a secondary hole portion 20.sub.2 in the second row can be defined shorter than the secondary hole portion 20.sub.1 in the first row. Thus, when longer and shorter ribs of the setting jig of the press-fitting unit, for example, are engaged with the hole portions 20.sub.1, 20.sub.2, it can be prevented that a flat harness 1.sub.3 is fitted in error not only inside out but also front side back. Therefore, the circular hole portion 6 for preventing the front/back reversed fitting is not needed.

(29) In FIG. 3, the longer hole portions 4 and the shorter hole portions 5 are integrated together respectively to constitute two longer secondary hole portions 20 that are longer than the longer hole portions 4 in FIG. 1 and have a different length respectively. When three coupling plate portions 3 or more are present between the conductor portions 2, three longer secondary hole portions 20 or more can be formed by this approach. In this case, the secondary hole portions 20 having a different length sequentially can be formed by changing sequentially a lapping margin between the longer primary hole portion 4 and the corresponding shorter primary hole portion 5.

(30) The longer secondary hole portions 20 are used when the flat harness 1.sub.3 is bent along the plate width direction, for example. Because the lapping margin between the longer primary hole portion 4 and the corresponding shorter primary hole portion 5 can be changed sequentially, the secondary hole portions 20 can be formed to prolong a length sequentially. The flat harness 1.sub.3 is bent such that the shorter secondary hole portion 20.sub.2 side is located on the bending inner side (the longer secondary hole portion 20 is located on the bending outer side). In this case, the secondary hole portion 20 can be used to engage the longer positioning ribs in the press-fitting or insert the press-fitting pieces of a plurality of the press-fitting terminals, for example, except the bending of the flat harness.

(31) The secondary hole portion 20 can be formed, for example, by lifting the middle circular punch 10 to be set free after the primary hole portions 4 are punched by the longer punch 9 in FIG.5, and then moving the shorter punch 11 up to the longer punch 9 and then bringing down the shorter punch 11 while touching the longer punch 9. In that case, the dies 12, 14 are moved together with the punches 9, 11. When the shorter hole portions 5 are caused to lap over the longer primary hole portions 4, the shorter punch 11 is moved toward the longer punch 9 in a condition that the longer punch 9 and the circular punch 10 are moved upward or frontward to be set free. This can be done when the shorter hole portions 5 are not lapped over the longer hole portions 4. The flat harness itself can be moved instead of moving the punches 9, 11.

(32) FIG. 4 shows a flat harness 1.sub.4 in which further longer tertiary hole portions 23 are formed by forming further the longer primary hole portions 4 and the shorter primary hole portions 5 in the secondary hole portions 20 of the flat harness 1.sub.3 in a mode shown in FIG. 3 to be connected to or lapped over them.

(33) In FIG. 4, a longer tertiary hole portion 23.sub.1 in the first row is formed to have a length obtained when two longer primary hole portions 4.sub.1 and two shorter primary hole portions 5.sub.1 are continued linearly. A longer tertiary hole portion 23.sub.2 in the second row is formed to have a length obtained when a lapping margin between one longer primary hole portion 4.sub.2 and one shorter primary hole portion 5.sub.2 is subtracted from the longer tertiary hole portion 23.sub.1 in the first row.

(34) Two longer hole portions 4 are formed when the longer hole portions 4 are punched by moving the longer punch 9 in FIG.5 up to the other end of the secondary hole portion 20 in FIG.3 and falling down the longer punch 9, and subsequently or precedingly the shorter hole portions 5 are punched by moving the shorter punch 11 in FIG.5 up to one end of the secondary hole portion 20 in FIG.3 and falling down the shorter punch 11. The dies 12, 14 in FIG.5 may be moved simultaneously with the movement of the punches 9, 11, otherwise a long die (not shown) containing a distance within the punches 9, 11 are moved may be formed in advance.

(35) Here, the longer tertiary hole portions 23 in FIG.4 can be formed by forming continuously the longer hole portions 4 and the shorter hole portions 5 in addition to the longer and shorter primary hole portions 4, 5 in FIG.1, for example, instead of the secondary hole portion 20 in FIG.3. In this case, the circular hole portion 6 in FIG.1 is eliminated by punching the longer hole portion 4 to overlap with it. The number of punching times of the longer punch 9 and the shorter punch 11 is not limited to twice, and respective hole portions can be punched in the appropriate number of times according to the necessary length of the hole portions.

(36) Also, the hole portion that is shorter than the longer tertiary hole portion 23.sub.1 in the first row in the longitudinal direction may be formed by omitting the punching of the shorter hole portions 5.sub.2 on one end side of the longer tertiary hole portion 23.sub.2 in the second row in FIG. 4. Also, the longer tertiary hole portion may be formed by forming only one longer hole portion 4 and then causing a plurality of shorter hole portions 5 to be connected to such longer hole portion 4.

(37) A sufficient length can be assured by the longer tertiary hole portion 23 in FIG. 4. For example, the longer hole portion used to bend the flat harness 1.sub.4, the longer hole portion engaged with the longer rib of the setting jig at a time of press-fitting, and the longer hole portion through which the press-fitting pieces of plural press-fitting terminals are passed can be formed in a necessary length respectively.

(38) According to the flat harness machining method in FIG.1 to FIG.4, the hole portions 20, 23 having a different length as the case may be can be formed simply without fail by moving the same punches 9, 10. Therefore, a productivity of the flat harness 1 (1.sub.1 to 1.sub.4) can be improved and also a size reduction and a cost reduction of the punching machine can be achieved because of a reduction of the punches (punching devices). Also, since another large hole portion 20 is formed by deleting the positioning hole portion used at a time of press-fitting by virtue of the punching, the worker never confuses another hole portion 20 with the positioning hole portion 6. Therefore, the workability in fitting the flat harness 1 to the vehicle, or the like, forexample, can be improved.

(39) In the above embodiments, the hole portions 4 to 6 are punched and formed by using the punching machine 8 equipped with the first punching device 21 and the second punching device 22. But three types or more of hole portions can be punched and formed by using the punching machine equipped with three punching devices or more.

(40) Although the invention has been illustrated and described for the particular preferred embodiments, it is apparent to a person skilled in the art that various changes and modifications can be made on the basis of the teachings of the invention. It is apparent that such changes and modifications are within the spirit, scope, and intention of the invention as defined by the appended claims.

(41) The present application is based on Japan Patent Application No. 2005-083760 filed on Mar. 23, 2005, the contents of which are incorporated herein for reference.