JP3434974B2 - I/O unit structure in a numerical control device - Google Patents

Description

Detailed Description of the Invention

[0001]

The present invention relates to an improvement in the structure of an I/O unit in a numerical control device.

[0002]

2. Description of the Related Art There are several methods for mounting an I/O unit on a distribution board, including a method for screwing the casing of the I/O unit directly onto the distribution board, and a method for mounting the I/O unit on a DIN rail provided on the distribution board.
A method is known in which the /O unit and the power supply unit are fixed to each other by fitting a through groove formed in the casing of the /O unit.

[0003] According to the method of screwing the I/O unit casing directly to the distribution board, the I/O unit can be attached using a small space, but the problem is that the need for many screws makes it difficult to attach and remove the I/O unit. On the other hand, with a configuration using a DIN rail and through groove, the I/O unit can be easily attached and removed without using screws, but since the DIN rail is provided on the distribution board side, a certain amount of free space is required on both sides of the casing, and it is not always possible to arrange various electrical components in a densely packed manner.

Since each of these has its own advantages and disadvantages, it is necessary to use either a screw-type I/O unit or a DIN rail type I/O unit.
Whether or not to use an I/O unit depends on the final design concept, but the structure of the I/O unit must also be changed accordingly. In reality, even if the mounting concept differs, the shape of the casing itself does not differ significantly, and it is merely a minor change, but since the final product shape differs, two production lines are required, which tends to increase the final manufacturing cost.

[0005] Furthermore, in conventional I/O units, the distribution board and the I/O unit were always connected via an extension cable, which caused the problem of the distribution board becoming congested with this extension cable as well as other extension cables from external devices.

[0006]

The object of the present invention is to provide a single structure that can handle multiple mounting methods,
Another object of the present invention is to provide an I/O unit structure in a numerical control device that can reduce the congestion of cables on a distribution board.

[0007]

The present invention provides a method for connecting a data input/output circuit to a data distribution board by providing a terminal on a first surface of the data distribution board and a locking means for locking the data distribution board .
A second surface parallel to the first surface has a through hole that fits with the mounting rail.
Through groove and screw fastening holes for directly fixing the casing
The above-mentioned object is achieved by providing a terminal on the third surface for connecting to a connector provided at the end of another extension cable, and electrically connecting each of the terminals via the data input/output circuit.

[0008] The above configuration maintains compatibility with conventional installation methods, and furthermore, for distribution boards that are compatible with this I/O unit structure, it is possible to achieve electrical and mechanical connections simultaneously without the need for extension cables. Eliminating the need for extension cables between the I/O unit and distribution board helps to reduce the clutter of cables on the distribution board.

Furthermore, by providing screw fastening holes for directly fastening the casing on one surface of the polyhedral casing on which no terminals are provided, it is possible to accommodate the conventional mounting method using screws.

[0010] Also, a second surface parallel to the first surface is provided.
The through groove that fits the mounting rail and the casing are fixed directly.
By providing a screw fastening hole for the mounting structure,
This has expanded the freedom of choice.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will now be described with reference to the drawings. Figures 1 and 2 are perspective views showing the external appearance of a casing 1 of an I/O unit according to an embodiment of the present invention.

[0012] Both Figures 1 and 2 show the same casing 1, but Figure 1 mainly shows surface 1a which has a through groove 3 that fits with a DIN rail 2 and a screw fastening hole 4 for direct fastening, while Figure 2 mainly shows surface 1b which has a terminal group 7 which connects to a connector 6 on a distribution board 5 and engagement pieces 10, 11 which engage with holes 8, 9 which are locking means on the distribution board 5.

As shown in Figures 1 and 2, the casing 1 of this embodiment is formed as a flat rectangular parallelepiped overall, and is composed of left and right side surfaces 1c, 1d, and outer peripheral surfaces 1a, 1b, 1e, and 1f formed to cover the outer periphery of the left and right side surfaces 1c, 1d.

As shown in FIG. 2, a rectangular cutout 12 is formed in the center of the surface 1b of the casing 1, into which the connector 6 mounted on the distribution board 5 is fitted.
Within the housing 1, a group of terminals 7 for electrical connection to the group of terminals of the connector 6 are neatly arranged at a position recessed inward from the surface of the face 1b by the thickness of the connector 6.

[0015] Furthermore, at the upper end of surface 1b, an L-shaped engagement piece 10 with its tip bent inward is formed integrally with the casing 1, and at the lower end of surface 1b, an engagement piece 11 having a wedge-shaped protrusion 13 at its tip that protrudes outward is formed integrally with the casing 1.

The flexible arm 14 of the engaging piece 11 rises not on the surface 1b but on the surface 1f, and moreover, the surface 1b and the surface 1f are
f is located at a position quite far away (step A in the figure).
The flexible arm 14 of the engagement piece 11 is provided with a sufficient span for elastic deformation.

The engaging pieces 10 and 11 are engaging means for connecting with the holes 8 and 9 on the distribution board 5.

The vertical width of the hole 8, which is one of the locking means on the distribution board 5, is formed slightly wider than the vertical width of the tip of the engagement piece 10 so that the tip of the engagement piece 10 can easily enter the hole 8.
The positional relationship of the hole 8 with respect to the engaging piece 10 is adjusted so that when the inner corner portion 10a of the engaging piece 10 is crimped against the lower edge 8a of the hole 8, the distance from the lower edge 8a of the hole 8 to the tip of each terminal of the connector 6 and the distance from the inner corner portion 10a of the engaging piece 10 to the tip of each terminal of the terminal group 7 exactly match.

[0019] Therefore, by simply crimping the casing 1 to the distribution board 5 with the engaging piece 10 hooked onto the lower edge 8a of the hole 8, each terminal of the connector 6 and each terminal of the terminal group 7 can be reliably positioned and joined.

Generally speaking, when connecting and disconnecting connectors, the correct way to do so is to hold both terminals in parallel and apply a tensile or compressive force along the axial direction of the terminals. However, as far as this embodiment is concerned, the distance between the hole 8 and the connector 6 and the engagement piece 1 are
Since the distance between the engaging piece 10 and the terminal group 7, in other words, the radius of rotation of the path of the movement of the tip of the terminal group 7, is far longer than the effective length of the terminal itself, even if the terminal is attached or detached by a swinging motion centered on the engaging piece 10, there is no problem at all with the terminal bending or coming loose or breaking due to biting.

[0021] On the other hand, the position of hole 9, which is the other engaging means on the distribution board 5, is adjusted so that when the casing 1 is swung with the inner corner portion 10a of the engaging piece 10 pressed against the lower edge 8a of hole 8 and its lower end is pressed against the distribution board 5, the inclined portion of the wedge-shaped protrusion 13 on the engaging piece 11 on the casing 1 side abuts against the lower edge 9a of hole 9.

The inclined surface of the wedge-shaped projection 13 is aligned with the lower edge 9a of the hole 9.
When the lower end of the casing 1 is further pressed against the distribution board 5 while in contact with the flexible arm 14 of the engagement piece 11, the flexible arm 14 of the engagement piece 11 is bent, and the wedge-shaped projection 13 enters the hole 9 with its inclined surface in sliding contact with the lower edge 9a. Then, when the connection between the connector 6 and the terminal group 7 is completed and the wedge-shaped projection 13 completely passes through the hole 9, the flexible arm 14 elastically returns to its original shape, and the rising portion of the wedge-shaped projection 13 catches on the lower edge 9a of the hole 9, fixing the casing 1 in place.

That is, the engaging piece 10 is inserted into the hole 8 of the distribution board 5.
The engaging piece 11 has the function of suspending the casing 1 from the distribution board 5, the function of preventing the casing 1 from shifting laterally relative to the distribution board 5, and the function of preventing the upper end of the casing 1 from moving away from the distribution board 5, and the engaging piece 11 has the function of preventing the lower end of the casing 1 from shifting laterally relative to the distribution board 5, and the function of preventing the lower end of the casing 1 from moving away from the distribution board 5.

Therefore, as long as the casing 1 is suspended from the distribution board 5 in the normal mounting direction as shown in FIG. 1, no force acts between the connector 6 and the terminal group 7 which would shear the terminals.

[0025] When the casing 1 is attached to the distribution board 5 in an irregular manner, for example when the casing 1 is attached to the distribution board 5 upside down, or when it is necessary to connect or disconnect other cables while the casing 1 is attached to the distribution board 5, a force may act on the casing 1 from below in the direction shown in Figure 1. However, in this embodiment, the overall dimensions are adjusted so that when the casing 1 is attached to the distribution board 5, the underside 15a of the base 15, which serves as the mounting base for the connector 6, is in close contact with the wall surface 12a of the cutout 12 on the casing 1 side, and therefore the force that would push the casing 1 from below is supported by the contact surface between the base 15 and the cutout 12, and the casing 1 can adequately withstand such a force.

When removing the casing 1 from the distribution board 5, reach behind the distribution board 5, lift the wedge-shaped projection 13 of the engagement piece 11 to remove it from the hole 9, pull the engagement piece 11 out of the distribution board 5, and then slide the entire casing 1 upward to pull the locking piece 10 out of the hole 8. Also, as already mentioned, since the flexible arm 14 of the engagement piece 11 has a sufficient span, it is possible to release the engagement between the wedge-shaped projection 13 and the lower edge 9a of the hole 9 and remove the casing 1 by simply pressing the flexible arm 14 with a finger against the main body of the casing 1, without having to reach behind the distribution board 5.

As shown in the example of FIG. 1, if a distribution board is configured to correspond to the casing 1 of the embodiment, that is, a distribution board 5 on which a connector 6 is mounted and holes 8 and 9 are provided, then the distribution board 5 shown in FIG.
Even without using the extension cable 22 as shown in FIG. 1, it is possible to simultaneously achieve the mechanical connection between the distribution board 5 and the casing 1 and the electrical connection between the connector 6 of the distribution board 5 and the terminal group 7 of the casing 1, and since the extension cable 22 is not interposed, the congestion of extension cables near the distribution board can be alleviated compared to the conventional connection method.

The through groove 3 serving as the second mounting means and the screw fastening hole 4 serving as the third mounting means are shown in FIG.
1, the terminal group 7 is provided on the surface 1a of the casing 1, which is parallel to the surface 1b on which the terminal group 7 is provided.

The width of the through groove 3 is determined by the width of the DI
The upper side wall 3a is formed with a reverse tapered slope that fits onto the upper edge of the DIN rail 2, while the lower side wall 3b is formed with a reverse tapered slope that fits onto the upper edge of the DIN rail 2.
The through groove 3 can be freely engaged with and disengaged from the DIN rail 2.
The through groove 3 has an inclined surface that opens outward. A protrusion 3c is formed at the top of the through groove 3 for sandwiching the upper edge of the DIN rail 2 between the side wall 3a (see FIG. 3).
On the side of the side wall 3b, a locking claw 16 is provided integrally with the casing 1 for fastening the lower edge of the through groove 3 to the lower edge of the DIN rail 2 with the side wall 3a hooked onto the upper edge of the DIN rail 2.

The locking claw 16 is fitted into the notch 20 of the casing 1.
The flexible arm 17 is provided inside the tool holder 11, and a wedge-shaped projection 18 is formed on the upper surface of the tip of the flexible arm 17. The tool holder 11 has a cutout 18 for hooking a tool formed integrally with the lower surface of the tip of the flexible arm 17.
The flexible arm 17 has a sufficient span for elastic deformation, similar to the engagement piece 11 described above. The relationship of the wedge-shaped projection 18 to the lower edge of the DIN rail 2 is as follows: the engagement piece 14 is connected to the lower edge 9a of the hole 9 in the distribution board 5.
1. The relationship between the wedge-shaped projections 13 is the same as that of the projections 13 of FIG.

The locking claw 16 may be completely integrated with the casing 1 made of synthetic resin (plastic), or
Alternatively, only the locking claw 16 may be constructed separately and attached to the casing 1 in a nested manner. For example, a slit may be provided at the portion 21 of the casing 1 shown in the figure,
It is possible to attach the base of the flexible arm 17 of the locking claw 16 by press-fitting it into this portion. The casing 1 itself is a plastic molded product consisting of two halves, left and right, with a data input/output circuit board sandwiched inside and assembled integrally with concave-convex fitting parts provided on the fitting surfaces of both the left and right halves of the main body, without using any screws for assembly.

When mounting the casing 1 on the DIN rail 2 on the distribution board using the through groove 3, first,
The side wall 3a of the casing 1 is hooked onto the upper edge of the DIN rail 2, and then the lower end of the casing 1 is pressed against the DIN rail 2 so that the wedge-shaped projections 18 of the locking claws 16 are engaged with the DIN rail 2.
The lower edge of the nut should be engaged with the lower edge of the nut.

For removal, a tool such as a flat head screwdriver is inserted into the tool hooking notch 19 of the locking claw 16, the flexible arm 17 is pulled downward to disengage the wedge-shaped projection 18 from the lower edge of the DIN rail 2, the lower end of the casing 1 is pulled away from the DIN rail 2, and then the entire casing 1 is slid upward to pull the side wall 3a of the through groove 3 away from the upper edge of the DIN rail 2. The gap between the lower end of the tool hooking notch 19 and the bottom 20a of the notch 20 is sufficient to pull the wedge-shaped projection 18 down and disengage it from the lower edge of the DIN rail 2, so that the removal of the wedge-shaped projection 18 can be easily performed and the flexible arm 1
7 is bent to the maximum limit allowed by the gap, and the lower end of the tool hooking notch 19 contacts the bottom 20 of the notch 20.
The span and material of the flexible arm 17 are adjusted so that the amount of bending of the flexible arm 17 falls within the range of elastic deformation even when it hits point a, so that damage such as breaking or buckling of the flexible arm 17 can be reliably prevented.

When the casing 1 is attached to the DIN rail 2, both the upper and lower edges of the DIN rail 2 are in the through groove 3.
Since the base corners of the side walls 3a, 3b are tightly fitted to the casing 1, the casing 1 can withstand both a load applied from above and a force acting as if pushing up from below.

Furthermore, the inclined surface of the side wall 3a and the protrusion 3c are fitted with a DIN
The upper edge of the rail 2 is elastically clamped, so that
The casing 1 can be prevented from shifting laterally with respect to the rail 2. In other words, strictly speaking, the side wall 3a is hooked on the uppermost edge of the DIN rail 2, and the casing 1 can be prevented from shifting laterally with respect to the rail 2.
The height of the protrusion 3c is adjusted so that a certain amount of gap is created between the lower edge of the DIN rail 2 and the lower edge of the through groove 3 when the tip of the protrusion 3c is in contact with the surface of the upper edge of the DIN rail 2. Furthermore, from this state, the wedge-shaped protrusion 18 of the locking claw 16 is
When the lower end of the casing 1 is pressed against the DIN rail 2 until it engages with the lowermost edge of the DIN rail 2, the through groove 3
Specifically, in FIG. 3, the through groove 3 is deformed into a right-opening parentheses "(" shape. The repulsive force due to this elastic deformation, the side wall 3a, the protrusion 3c, and the wedge-shaped protrusion 18
The three-point support by the brackets means that the casing 1 is fixed to the DIN rail 2 so as not to shift laterally.

[0041] The only function required for the locking claw 16 is to prevent the side wall 3 b of the through groove 3 from moving away from the lower edge of the DIN rail 2 .

When the casing 1 is mounted on the distribution board using the DIN rail 2, this alone does not electrically connect the casing 1 to the distribution board, so it is necessary to connect the connector 23 provided at the end of the extension cable 22 from the distribution board to the terminal group 7 of the casing 1.
The pin arrangement of this connector 23 is the same as that of the connector 6 described above.

[0038] Screw fastening hole 4 serving as the third mounting means
The locking claws 16 are drilled into a flange portion 24 protruding from the outer periphery of the surface 1a of the casing 1, and are adapted to be directly attached to the distribution board by inserting a tapping screw or the like from the casing 1 side and screwing it into a screw hole on the distribution board.
a, or set back from it, they do not get in the way when screwing, and as long as there is enough space to overlap surface 1a of casing 1 with the distribution board surface, casing 1 can be easily attached by screwing. Of course, even if there are no screw holes, as long as there is enough space, it is possible to easily create holes for tapping screws by post-processing with a hand drill or the like on the distribution board surface. When directly attaching casing 1 to the distribution board with screws,
As described above, this alone does not electrically connect the casing 1 to the distribution board, so a connector 23 provided at the end of an extension cable 22 extending from the distribution board is connected to the casing 1.
It is necessary to connect the terminals 7 of the first embodiment to the second embodiment.

[0039] The surface on which the screw fastening hole 4 is provided and the surface on which the through groove 3 is provided do not necessarily have to be the same surface, but by providing them on the same surface, it becomes possible to arrange a large number of terminal groups 25a, 25b for extension cables used to connect to external devices and terminal groups for extension cables 26a, 26b on the remaining two surfaces of the casing 1, i.e., surfaces 1e and 1f.

[0040]

According to the I/O unit structure of the present invention,
A single casing structure can be used with mounting rails, screws, and even dedicated mounting structures, so users can freely choose the mounting structure that best suits their needs to install the I/O unit. In particular, when a dedicated mounting structure is used, an extension cable connecting the distribution board and the I/O unit is not required, which can reduce the congestion of extension cables on the distribution board. In addition, manufacturers do not need to use separate production lines for different mounting structures, and can consolidate the production line for I/O unit casings to reduce manufacturing costs, making it possible to provide I/O units that can be installed in a variety of ways at low prices.

[Brief description of the drawings]

FIG. 1 is a perspective view showing the appearance of a casing of an I/O unit according to an embodiment of the present invention;

FIG. 2 is a perspective view showing the appearance of the casing of the I/O unit of the embodiment from a different angle.

FIG. 3 is a simplified diagram showing an engagement state between a through groove and a DIN rail.

[Explanation of symbols]

1 Casing of I/O unit 1a Surface 1b with through groove and screw fastening hole 1c Surface with terminal and engagement means to be connected to the connector of the distribution board Left side 1d Right side 1e Outer surface 1f Outer surface 2 DIN rail 3 Through groove 3a Side wall 3b Side wall 3c Protrusion 4 Screw fastening hole 5 Distribution board 6 Connector fixed to distribution board 7 Terminal group 8 to be connected to the connector fixed to the distribution board Hole (locking means) 8a Lower edge 9 Hole (locking means) 9a Lower edge 10 Engagement piece (engagement means) 10a Inner corner portion 11 Engagement piece (engagement means) 12 Notch 12a Wall surface 13 Wedge-shaped protrusion 14 Flexible arm 15 Base 15a Lower surface 16 Engagement claw 17 Flexible arm 18 Wedge-shaped protrusion 19 Tool hooking notch 20 Notch 20a Bottom 21 (slit) 22 Extension cable 23 Connector 24 Flange portion 25a Terminal group 25b Terminal group 26a Extension cable 26b Extension cable

─────────────────────────────────────────────────────────── Continued from the front page (56) References JP 5-88726 (JP, A) JP 63-88605 (JP, A) Jpn. Pub. No. 6-30802 (JP, U) (58) Fields surveyed (Int.Cl. ⁷ , DB name) G05B 19/18 - 19/46 B23Q 15/00 - 15/28 H05K 7/02 - 7/10

Claims (2)

(57) [Claims] [Claim 1] In an I/O unit structure for a numerical control device having a rectangular parallelepiped casing containing a circuit for data input/output, the casing has, on a first surface, terminals for connecting with a connector on a distribution board and engaging means for engaging with a locking means provided on the distribution board, and on a second surface parallel to the first surface , a through groove for engaging with a mounting rail and a screw fastener for directly fixing the casing.
a hole for connecting to a connector provided at the end of another extension cable is provided on a third surface, and a terminal for connecting to the connector provided at the end of another extension cable is provided on a third surface, and each of the terminals is electrically connected via the data input/output circuit. [Claim 2] An I/O unit structure in a numerical control device as described in claim 1, characterized in that one of the surfaces of the casing on which no terminals are provided is provided with a screw fastening hole for directly fastening the casing.