JPH0323635Y2 - - Google Patents

Description

[Detailed Description of the Invention] Technical Field The present invention relates to a limit switch unit that detects when a moving member performing a predetermined movement reaches a predetermined position.

BACKGROUND OF THE INVENTION In various automatic processing machines, machine tools, etc., limit switches are often used as a means for detecting when a moving member performing a predetermined movement has reached a predetermined position. Such limit switches generally include an operating lever or the like for switching the switch, and are used in pairs with an engaging member that engages with the operating lever or the like to switch the contacts of the switch. . That is, a limit switch and an engaging member are attached to one and the other of a moving member and a fixed member located near the moving member, and the limit switch and engaging member are moved relative to each other as the moving member moves. When the operating lever of the limit switch or the like is engaged with the engaging member, the switch is switched and the position of the moving member is detected.

Problems to be Solved by the Invention However, the work of attaching the limit switch and the engaging member to separate members in this way is troublesome and troublesome, and the assembly efficiency is poor. In particular, when detecting multiple positions of a moving member, it is necessary to install multiple sets of limit switches and engaging members, which makes the above-mentioned inconvenience even more noticeable, and requires a large installation space. Another problem was that the degree of freedom in design was restricted.

Means for Solving the Problems The present invention was made to solve the above problems, and its gist is that the movable members performing predetermined interlocking movements reach a predetermined position. A limit switch unit for detecting a limit switch unit comprising: (a) a unit main body that is immovably provided on either one of the movable member and a fixed member located near the movable member; and (b) the unit body. (c) a take-up reel attached to the main body so as to be rotatable about an axis; and (c) one end of which is locked to the take-up reel and the other end of which is pulled out from the unit main body, and the movable member and the fixed member. (d) urging means for urging and rotating the take-up reel in a direction in which the connecting member is wound around the take-up reel; e) Detecting that the movable member has reached a predetermined position by engaging with an engaging member that is fixedly provided on the unit main body and rotated in response to rotation of the take-up reel. The reason is that it is configured to include a limit switch.

Function and Effects of the Invention In such a limit switch unit, the unit main body provided with the take-up reel, limit switch, etc. is fixed to a moving member or a fixed member, and the other end of the connecting member is pulled out from the unit main body. By connecting the movable member to the other of the fixed member, when the movable member and the fixed member are relatively separated, the connecting member is pulled out and the take-up reel resists the urging force of the urging means and moves away from the moving member. On the other hand, when the movable member and the fixed member relatively approach each other, the take-up reel rotates while winding up the connecting member according to the amount of movement of the moving member and the fixed member, according to the urging force of the urging means. I am made to do so. Then, the engaging member rotated in accordance with the rotation of the take-up reel is engaged with the limit switch, and the position of the moving member is detected. Therefore, there is no need to separately attach the limit switch and the engaging member as in the past, making the attachment work easier and improving the efficiency of assembly. In addition, the movement of the movable member is converted into the rotation of the take-up reel via the flexible connecting member, so the unit body can be placed and configured in any location, making it easy to install. Fewer restrictions. Furthermore, when detecting multiple positions of the moving member, for example, while providing a plurality of engaging members that rotate in response to the rotation of the take-up reel, it is also possible to Because it is sufficient to place the limit switches in the corresponding positions, assembly efficiency is not impaired, and the installation space is not increased and the degree of freedom in design such as installation position is not restricted. be.

On the other hand, in the present invention, since the connecting member is wound onto the take-up reel, compared to the case where the take-up reel is rotated using a rack or the like,
The unit becomes more compact and the degree of installation freedom is further improved.

Embodiment Hereinafter, an embodiment of the present invention will be described in detail based on the drawings.

In FIG. 1, 10 is a limit switch unit of this embodiment, which detects when the output rod 14 of the cylinder 12 has reached a predetermined position. The output rod 14 constitutes a movable member, and is adapted to be reciprocated in the left-right direction in FIG. It is designed to detect edges. The limit switch unit 10 and cylinder 12 are fixed to a fixing member (not shown).

Limit switch unit 10 is shown in detail in FIGS. 2-4. In these figures, reference numeral 16 denotes a unit main body that is attached to the fixing member, and is fixed by inserting bolts or the like into a plurality of mounting holes 17 so as to be immovable relative to the fixing member. This unit body 1
6, a rotating shaft 18 is mounted rotatably about the shaft, and a pair of limit switches 20, 22 are fixedly provided via a bracket 24.

The rotating shaft 18 is integrally provided with a large-diameter portion 26 at its lower end, and has a cylindrical pin 28 erected at the center of its upper end surface. The large diameter portion 26 is slidably fitted into a cylinder 30 fixed on the unit body 16, and a ball 32 is interposed between the large diameter portion 26 and the unit body 16 at the center of its lower end surface. , the pin 28 is rotatably inserted into an insertion hole 36 of a bracket 34 fixed to the unit body 16. As a result, the rotating shaft 18
is in a state where it can easily rotate around its axis,
It is arranged on the unit main body 16.

A reel 38, an engaging member 40, a spacer 42, and an engaging member 44 are fitted onto the rotating shaft 18 from the large diameter portion 26 side, and a nut 48 is further tightened via a presser foot 46 and a spring washer. is,
By press-fitting the reels 38 to the step portions of the large diameter portion 26, the reels 38 are fixed in a state in which relative rotation with respect to the rotating shaft 18 is prevented. reel 38
is equipped with a large-diameter winding part 50 that opens downward, and one end of a flexible steel band 52 is attached to the outer peripheral surface of the winding part 50 with a pin 54. A spiral spring 56 is disposed inside the winding section 50.

An engaging pawl 58 is provided at the inner end of the spring 56.
is provided and is engaged with a notch 60 formed on the outer peripheral surface of the cylinder 30, while the outer peripheral end is attached to a pin 62 erected on the reel 38. Due to the spring 56, the reel 38 is always urged to rotate clockwise in FIG. It is adapted to be held in a rotational position in which it abuts against. The other end of the steel band 52 extends outside from a notch (not shown) formed in a cover 66 (see FIG. 2) fixed on the unit main body 16, and is connected to the output rod 14.
It is attached to a mounting member 68 fixed to.

As a result, when the output rod 14 is moved toward the protruding side, the steel band 52 is pulled out to the other end side as the output rod 14 moves, and the reel 38 and further the rotating shaft 18 resist the biasing force of the spring 56. Third
While being rotated counterclockwise in the figure,
When the output rod 14 is retracted, the reel 3
8 Furthermore, the rotating shaft 18 is rotated clockwise while winding the steel band 52 around the outer peripheral surface of the winding portion 50 according to the biasing force of the spring 56. In this embodiment, these include the reel 38 and the steel strip 5.
2 and spring 56 correspond to a take-up reel, a connecting member, and a biasing means, respectively.

Note that the diameter of the winding portion 50 is such that the length around its outer circumferential surface is at least longer than the movement stroke of the output rod 14, more precisely the dimension between the moving end on the protruding side and the moving end on the retracting side. The dimensions are set. Further, a notch (not shown) is formed in the cover 66 so that the steel strip 52 can be pulled out in the direction shown by the dashed line in FIG. 3 as needed.

On the other hand, the engaging member 40 attached to the rotating shaft 18 is connected to the operating lever 7 of the limit switch 20 so as to engage with the limit switch 20.
It is placed at the same height as 0. The limit switch 20 is for detecting that the output rod 14 has reached the end of the movement on the protrusion side, and the engagement member 40 engages with the operating lever 70 when the output rod 14 has reached the end of the movement on the protrusion side. In the rotational phase in which the switch is switched, the rotational shaft 18
is fixed.

Further, the limit switch 22 is for detecting that the output rod 14 has reached the retracting end of the movement.
is located at the same height as the output rod 14.
When the lever reaches the end of the movement on the retraction side, the actuating lever 7
2 and is fixed to the rotating shaft 18 in the rotational phase in which the switch is switched. The upper end of the rotating shaft 18 is chamfered on two sides, and the presser foot 46 is fitted into the two-chamfered portion so that it cannot rotate relative to the rotating shaft 18. As a result, Natsu 4
This prevents the engaging member 44 and the like from rotating together with each other and shifting the rotational phase thereof when the locking member 8 is tightened.

When installing such a limit switch unit 10, it is necessary to mount the limit switch unit 10 at a predetermined position based on both moving ends of the output rod 14, the rotational phase of the engaging members 40 and 44, the length dimension of the steel band 52, etc. The unit main body 16 may be fixed to the mounting member 68, and the other end of the steel band 52 may be attached to the mounting member 68.

Therefore, compared to the conventional case where the limit switch and the engaging member are separately attached to predetermined positions, the attachment work becomes easier and the efficiency of assembly is improved. In particular, in this embodiment, two sets of limit switches 20, 22 and corresponding engaging members 40, 44 are integrally incorporated on the unit main body 16 in order to detect both ends of movement of the output rod 14. Therefore, compared to the case where they are attached separately, the effect of improving the assembly efficiency is extremely large, and the degree of freedom in design such as the attachment position is not restricted.

In addition, such a limit switch unit 10
can be disposed at any position where the steel strip 52 is pulled out as the output rod 14 is extended or retracted, which further improves the degree of freedom in design, such as the mounting position.

In addition, in this embodiment, the output rod 14 and the rotating shaft 18 are connected via a flexible steel band 52,
Since the rotating shaft 18 is rotated with the movement of the output rod 14, this is compared to, for example, a case where a rack that moves parallel to the output rod 14 is engaged with a pinion to rotate the rotating shaft 18. Therefore, the apparatus can be constructed compactly, and there is no need to arrange the rack parallel to the output rod 14.

Incidentally, when detecting both moving ends of the output rod 14 without using such a limit switch unit 10, for example, as shown in FIG. Engagement members 7 are mounted separately at the respective positions and engage the limit switches 20 and 22, respectively, when the output rod 14 reaches both ends of movement.
It was necessary to attach the moving rod 78 provided with the moving rods 4 and 76 to the output rod 14 via the attachment member 80. For this reason, the assembly efficiency is low, and a large installation space is required, which limits the degree of freedom in design. Also, mobile rod 78
This necessitated the troublesome work of providing the rod so that it could move in a direction parallel to the output rod 14.

Next, another embodiment of the present invention will be described. In addition,
In the following embodiments, parts common to those in the above embodiments are given the same reference numerals and explanations will be omitted.

In FIG. 5, a fixed shaft 84 having a large diameter portion 82 at its lower end is erected on the unit main body 16, and a rotary cylinder 86 is rotatably fitted onto the fixed shaft 84. The rotary cylinder 86 is attached to a stopper 9 attached to the upper end surface of the fixed shaft 84 with a bolt 88.
0 prevents the fixed shaft 84 from being pulled out from the upper end, while a large diameter take-up reel 92 is integrally provided at the lower end which is brought into contact with the stepped portion of the large diameter portion 82. The take-up reel 92 has the same structure as the take-up part 50, and has one end of the steel strip 52 attached to its outer peripheral surface, and the engaging claw 58 inside the large diameter part 82. A spring 56 is provided which is engaged with a notch 93 formed on the outer circumferential surface. In addition, the rotary cylinder 86
Engagement members 94 and 96, which can engage with the limit switches 20 and 22, respectively, are fitted into the members, and are fixed to the rotary cylinder 86 so as not to be relatively rotatable at predetermined rotational phases by setscrews 98 and 100, respectively.

In this case as well, the same functions and effects as in the embodiment described above can be obtained.

Hereinafter, embodiments of the present invention have been described in detail based on the drawings, but the present invention can also be implemented in other embodiments.

For example, in the embodiment described above, the limit switch unit 10 detects the position of the output rod 14 that performs linear reciprocating motion.
The present invention can be similarly applied to the case of detecting that a moving member that performs a linear reciprocating motion other than 4, or a moving member that performs a movement other than a linear reciprocating motion such as a rotational motion has reached a predetermined position.

Further, the limit switch unit 10 of the embodiment described above includes two sets of limit switches 20, 22 and engaging members 40, 44 or 94, 96 in order to detect both moving ends of the output rod 14. However, if only one end of the movement of the output rod 14 is to be detected, it is sufficient to provide only one set of limit switches and engaging members; It is also possible to configure the system to detect three or more positions. In this case, it is also possible to operate a plurality of limit switches with one engaging member.

Further, in the above embodiment, the unit main body 16 is provided on the fixed member to detect the moving end of the output rod 14, but the unit main body 16 is provided on the moving member and the other end of the steel strip 52 is provided on the fixed member. By attaching it, the position of the moving member can also be detected.

Further, in the embodiment described above, the engaging members 40, 44 and the engaging members 94, 96 are integrally fixed to the reel 38 and the take-up reel 92 and can be rotated by the same angle. In order to make the unit main body 16 more compact, the engaging member may be configured to be rotated via a speed reduction mechanism using gears or the like.

Further, in the above embodiment, the output rod 14 is connected to the output rod 14 by the steel band 52, but it is also possible to employ other flexible connecting members such as wire rope, and one winding on the take-up reel is also possible. It may be configured so that it is wound more than that. Furthermore, it is also possible to employ a chain as the connecting member and to use a sprocket as the take-up reel.

Although no other examples are given, the present invention can be implemented with various modifications and improvements based on the knowledge of those skilled in the art without departing from the spirit thereof.

[Brief explanation of drawings]

FIG. 1 is a plan view showing a limit switch unit according to an embodiment of the present invention arranged to detect the position of an output rod of a cylinder. FIG. 2 is a longitudinal sectional view of the limit switch unit of FIG. 1. FIG. 3 is a plan view of the limit switch unit of FIG. 1 with the cover removed. FIG. 4 is an exploded perspective view showing essential parts of the limit switch unit shown in FIG. 1. FIG. 5 is a sectional view showing the main parts of another embodiment of the present invention. FIG. 6 is a plan view showing an example of a conventional method for detecting the position of the output rod of a cylinder using a limit switch. 10... Limit switch unit, 14...
Output rod (moving member), 16...unit body,
20, 22... Limit switch, 38... Reel (take-up reel), 40, 44, 94, 96...
...Engagement member, 52...Strip steel (connection member), 56...
... Spring (biasing means), 92 ... Take-up reel.

Claims (1)

[Claims for Utility Model Registration] A limit switch unit that detects when a moving member that performs predetermined interlocking has reached a predetermined position, the unit being located at the moving member and in the vicinity of the moving member. a unit main body provided on either one of the fixed members so as not to be relatively movable; a take-up reel attached to the unit main body so as to be rotatable around an axis; a flexible long connecting member whose end portion is pulled out from the unit main body and connected to the other of the movable member and the fixed member; a biasing means for biasing and rotating the reel; and an engaging member provided in a fixed position on the unit main body and rotated in response to rotation of the take-up reel to engage with the movable member in advance. A limit switch unit comprising: a limit switch that detects when a predetermined position is reached.