JP3306646B2 - Limit switch - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a limit switch for setting an arbitrary lower limit position of an electric shutter which can be moved up and down, for example, vertically.

[0002]

2. Description of the Related Art As this kind of limit switch, one disclosed in Japanese Utility Model Publication No. 5-39196 has been proposed. The limit switch disclosed herein has a plurality of digits each having a concave portion formed on a peripheral surface thereof, and an operating member provided with an operating piece for operating the switch by engaging with the concave portion of the numeral wheel; Zero reset means for resetting the numeral wheel to zero is provided, and when all the numeral wheels indicate "0", the operating piece of the operating member is engaged with the concave portion to activate the switch. The limit switch is added to or subtracted from the numeral wheel in conjunction with the opening and closing of the electric shutter, and is reset to zero by the resetting means when the shutter reaches an arbitrary lower limit position. By setting an arbitrary lower limit position to the limit switch in this way, when the shutter moves down from the upper limit and reaches the set lower limit position, all the numeric wheels of the limit switch display "0", so the switch is activated. Then, the shutter stops automatically.

[0003]

In the conventional limit switch described above, the numeral wheel is added and the numeral wheel is displayed as "9".
When all digits are carried from "99" to "000", the backlash of the gear between the carry pinion interposed between the numeral cars and the gear of the numeral car that meshes with it causes the upper digit car Carry operation is slightly delayed. For this reason, the engagement between the operating member of the operating member and the concave portion is delayed, and the operation of the switch is also delayed. Due to this delay, the inertia of the motor itself after the motor for opening and closing the shutter is stopped causes the operating member of the operating member to be re-operated. There has been a problem that the switch may malfunction due to riding on the peripheral surface of the numeral wheel from the concave portion and lack reliability. Therefore, conventionally, the display of the numeral wheel is changed from “001” to [0] in conjunction with the lowering of the shutter.
It is necessary to connect the output shaft of the motor that is the drive source of the shutter and the input shaft of the limit switch so that the switch operates in the subtraction direction that is subtracted by "00" so that the switch does not malfunction. Had become.
However, the motor is configured to be mounted on either the left or right side of the shutter, and the rotation direction of the output shaft of the motor is reversed on the left and right. Therefore, the limit switch must be mounted so that the switch operates in the addition direction. In some cases, there is a problem in reliability as described above.

Accordingly, the present invention has been made in view of the above-mentioned conventional problems, and has as its object to prevent erroneous operation of a switch regardless of whether the switch is operated in both directions of addition and subtraction. And to provide a mitt switch.

[0005]

In order to achieve this object, a limit switch according to the present invention comprises a multi-digit wheel having a plurality of digits having recesses formed on a peripheral surface thereof, which can be added or subtracted, and a plurality of these wheels. A limit switch comprising: a zero-return means for returning to zero; and an operating member which engages each operating piece with each of the concave portions of the numeral wheel when all of the numeral wheels indicate "0" and activates the switch. The concave portion of the least significant digit wheel of the plurality of digit wheels is extended in the adding direction, and the concave portion of the upper digit numeral wheel is extended in the subtracting direction.
Therefore, the display of the numeric car changes from "999" to "000".
The delay of carry operation of the upper digit vehicle due to backlash between the carry pinion and the gear of the numeral car when all carry is carried out is extended in the subtraction direction of the upper digit car. It is adjusted with the recessed part. In addition, the limit switch according to the present invention shifts the engagement position of the operating piece corresponding to the lowermost digit wheel of the operating pieces with the concave portion in the subtraction direction,
The position of engagement of the operating piece corresponding to the higher-order digit wheel with the concave portion is shifted in the adding direction, and a play is provided between the operating piece and the concave portion in the rotation direction of the numerical wheel. Therefore,
When the display of the numeral car is all changed from "999" to "000", the delay of the carry operation of the upper numeral car due to the backlash generated between the carry pinion and the gear of the numeral car is as follows. The adjustment is made by shifting the engagement position of the operating piece corresponding to the higher-order digit wheel with the concave portion in the adding direction.

[0006]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Embodiments of the present invention will be described below with reference to the drawings. 1 is a cross-sectional plan view of a limit switch according to the present invention, FIG. 2 is a cross-sectional view taken along the line II-II in FIG. 1, and FIG. 4B is a side view showing a counting state, FIG. 4A is a side view showing a counting state, FIG. 4A is a side view showing a relationship between an operating member and a switch, and FIG. FIG. 5 is a side view showing a state when the numeral wheel displays “000”, FIG. 5A is a side view showing a state where the numeral wheel indicates “000”, and FIG. Shows the relationship between the numeral car and the carry pinion,
FIG. 6 is a diagram showing the positional relationship between the concave portion of the numeral wheel and the protrusion of the operating member when the numeral wheel is subtracted from “001” to “000”, and FIG. 7 is the addition of the numeral wheel from “999” to “000”. It is a figure which shows the positional relationship of the recessed part of the numeral wheel and the protrusion of an operation member when performing.

A limit switch, generally designated by the reference numeral 1,
A bracket 2 having a U-shaped cross section formed by both side plates 3 and 4 and a bottom plate 5 is provided. Reference numeral 6 denotes a transparent cover which is formed in a box shape on one side and covers a well-known counter 10 which will be described later. The transparent cover 6 is screwed to the other side plate 4 so that the opening is closed by the side plate 3. Reference numeral 7 denotes an input shaft rotatably supported by a bearing 8 attached to a hole formed in the side plate 2. One end of the input shaft 7 opens and closes an electric shutter whose lower limit is set by the limit switch 1. An intermediate gear 9 is fixed to the other end of the motor, which is connected to an output shaft of a driving motor (not shown).

The counter 10 includes a drive gear 16 meshing with the intermediate gear 9 and three first to third digit wheels 11, 12, and 13 integrally formed with a heart cam 14 on the side surface. It is rotatably supported by a shaft 15a which is laid between both side walls of the frame 15 formed in a letter shape. 17
Is a transmission gear interposed between the drive gear 16 and the first digit wheel 11, and 18 is a carry pinion interposed between the three numeral wheels 11, 12, 13.
The carry pinion 18 is rotatably supported by a shaft 22 which is laid on both arms of a zero return lever 19 having a U-shaped cross section.

The zero return lever 19 is rotatably supported by a shaft 20 laid between both side walls of the frame 15, and has a lower end engaged with the heart cam 14 so as to be orthogonal to the zero return lever 19. One heart cam pressing piece 21 is protruded. The zero return lever 19 is urged in the direction A in the figure around the shaft 20 by a torsion coil spring (not shown), and during normal counting operation, the transmission gear 17 and the carry pinion 18 are driven. Gear 16 and numeric wheel 11,1
The heart cam pressing piece 21 is separated from the heart cam 14 by meshing with gears formed on the side surfaces of the heart cam 2 and the gear 13.

Reference numeral 23 denotes a substantially cylindrical shape,
Is a set member rotatably supported on a shaft 29 which is suspended between both side walls of the arm 6. The arm 24 protrudes to one side and protrudes from an arc-shaped long hole of the cover 6 on the outer surface. A set pin 25 protrudes, and a protrusion 26 protrudes from the inner surface of the arm 24. At the lower portion of the set member 23, a fan-shaped pressing piece 27 having a concave portion 27a for engaging with the shaft 22 is formed at the lower end thereof. It is urged in the direction of arrow B in the figure by a torsion coil spring 30 interposed therebetween.

Reference numeral 32 denotes a substantially cylindrical member,
An actuating member rotatably supported by a shaft 33 suspended between both side walls of the actuating member 32. An engaging portion 34a is formed at a tip of an arm portion 34 formed on one side of the actuating member 32, Projections 35a, 36a, 37a are provided at the lower part, respectively.
The three operating pieces 35, 36, 37 project downward. 3
Reference numeral 8 denotes a switch fixed to a cut-and-raised piece 5 a cut and raised on the bottom plate 5 of the bracket 2, and an operation portion 38 a is engaged with the operation piece 37.

The projections 35 of the operating pieces 35, 36, 37 are provided on a part of the peripheral surface of the three numeral wheels 11, 12, 13.
The recesses 39, 40, and 41 with which the a, 36a, and 37a engage are recessed. As shown in FIG. 6 and FIG. 7, these concave portions 39, 40, 41
When “00” is displayed, the protrusions 35a,
It is recessed at a position engaging with 36a, 37a. The concave portion 39 of the first digit wheel 11 is extended in the addition direction to form an extended portion 39a, and the second digit wheel 3
The concave portions 40 and 41 of the 2nd and 13th are extended in the subtraction direction to form extended portions 40a and 41a.

Next, the operation of setting the lower limit position of the electric shutter by the limit switch having such a configuration will be described. The output shaft of a motor (not shown) for moving the electric shutter (not shown) up and down and the input shaft 7 of the limit switch 1 are connected to the input shaft 7 in the forward and reverse directions in conjunction with the up and down movement of the electric shutter. It is connected so as to be driven to rotate. First of this implementation
In the embodiment, the numeral wheel 1 is linked to the rise of the electric shutter.
1, 12, and 13 are connected so as to add and subtract in conjunction with the lowering of the electric shutter.

In such a structure, when the electric shutter is lowered to an arbitrary lower limit position where the lowering of the electric shutter is stopped, the motor is stopped to stop the lowering of the electric shutter, and the limit switch 1 is returned to zero. The operation is performed, and the lower limit position of the electric shutter is set to the limit switch 1. That is, as shown in FIG. 3, when the set pin 25 is pressed in the direction of arrow C against the bias of the torsion coil spring 30 in the direction of arrow B, the set
It rotates in the direction opposite to the arrow B around the rotation center 9. By this rotation, as shown in FIG.
Is engaged with the engaging portion 34a of the operating member 32 to rotate the operating member 32 about the shaft 33 in the direction of arrow E in the figure, so that the pressing portion 37 pushes down the operating portion 38a of the switch 38. The switch 38 is turned ON.

As shown in FIG. 1B, the shaft 22 engaging with the concave portion 27a of the pressing piece 27 of the set member 23 is
, The zero return lever 19 rotates in the direction of arrow F about the shaft 20 as the center of rotation. The rotation of the zero return lever 19 in the F direction causes the carry pinion 18 to rotate the numeral wheel 1.
Since the heart cam pressing piece 21 presses the heart cam 14, the numeral wheels 11, 12, 13
Are simultaneously reset to zero, and the lower limit position of the electric shutter is set to the display “000” of the numeral wheels 11, 12, and 13. At this time, the concave portions 39, 4 of all the numeral wheels 11, 12, 13
0, 41 are all operating pieces 35, 3 of the operating member 32.
The projections 35a, 36a, and 37a are positioned corresponding to the projections 6, 37.

After the lower limit position of the electric shutter is set to the limit switch 1, the pressing of the set pin 25 in the direction of arrow C is released, and the motor is driven to raise the electric shutter. As shown in FIG.
When the pressing in the direction of arrow C is released, the set member 23 is rotated in the direction of arrow B about the shaft 29 by the bias of the torsion coil spring 30. As shown in FIG. 3B, the zero return lever 19 is provided in the recess 2 of the pressing piece 27 of the set member 23.
Since the pressing by 7a is released, the torsion coil spring (not shown) rotates in the direction of arrow A about the shaft 20 as the rotation center.

Therefore, the heart cam pressing piece 21 is separated from the heart cam 14 of the hour wheel 11, 12, 13 and the pinion 18 is interposed between the hour wheel 11, 12, 13 so that the hour wheel 11, 12, 13 is counted. The rotation from the output shaft of the motor is transmitted to the input shaft 7 and
2 and 13 are added in conjunction with the rise of the electric shutter. When the electric shutter reaches the upper limit, the electric shutter cannot be raised any more, so that an overcurrent flows to the motor, so that this is detected and the motor stops. At this time, the projections 35a, 36a, 37a of the operating member 32 are
Since the vehicle rides on the peripheral surfaces of the operation members 12 and 13,
As a result, the actuating member 32 causes the arrow E
In this case, the operation lever 38 pushes down the operation portion 38a of the switch 38, and the switch 38 is turned ON.

Next, when the motor is rotated in the reverse direction to lower the electric shutter, the numeral wheels 11, 12, and 13 are subtracted, and the display of the numeral wheel becomes "001" as shown in FIG. 6 (a). The recesses 4 of the second and third digit wheels 12, 13
0, 41 correspond to the projections 36a, 37a of the operating member 32, and the recess 39 of the first digit wheel 11 is
Does not correspond to the projection 35a. The electric shutter is further lowered, and the numeral wheels 11, 12, and 13 are subtracted, and the display of the first numeral numeral 11 is "1" as shown in FIG.
Between “0” and “0”, the concave portion 3 of the first digit wheel 11
9 has an extending portion 39a formed in the adding direction, so that the projection 35a of the operating member 32 corresponds to the extending portion 39a, and the operating member 32 rotates the shaft 33 as shown in FIG. It rotates in the direction of arrow G as a moving center.

Therefore, the operating portion 38a of the switch 38
The switch 38 is turned off, and the motor of the electric shutter stops. At this time, the output shaft of the motor continues to rotate excessively due to the inertia of the motor itself, so that the first digit wheel 11 rotates in a direction to slightly subtract, and as shown in FIG. The display of the first digit numeral wheel 11 becomes "0" and stops. Therefore, the concave portion 39 of the first digit wheel 11 corresponds to the projection 35a of the operating member 32,
Therefore, the projection 35a does not run on the peripheral surface of the first digit wheel 11 due to the inertia of the motor itself, the motor does not malfunction, and the electric shutter is accurately stopped at an arbitrary lower limit set by the limit switch 1. I do.

Next, a description will be given of a second embodiment in which a motor is mounted on the opposite side in the left-right direction of the electric shutter from the first embodiment. In this case, the rotation direction of the output shaft 7 of the limit switch 1 connected to the output shaft of the motor is opposite to that in the first embodiment described above, and the numeral wheel 11, 1 of the limit switch 1 is used.
2 and 13 are subtracted when the electric shutter is raised, and are added when the electric shutter is lowered.

In such a configuration, similarly to the first embodiment, when the electric shutter is lowered to an arbitrary lower limit position where the lowering of the electric shutter is stopped, the motor is stopped to lower the electric shutter. Is stopped and the limit switch 1 is returned to zero, and the lower limit position of the electric shutter is set to the limit switch 1. That is, as shown in FIG. 3, when the set pin 25 is pressed in the direction of arrow C, the numeral wheels 11, 12, and 13 return to zero all at once, and the lower limit position of the electric shutter is set to any of the numeral wheels 11, 12 , 13 are set to “000”. At this time, the operating portion 38 of the switch 38 is
a is depressed and the switch 38 is turned on, and the concave portions 39, 40, 41 of all the numeral wheels 11, 12, 13 are set.
Are located corresponding to the projections 35a, 36a, 37a of all the operating pieces 35, 36, 37 of the operating member 32.

After the lower limit position of the electric shutter is set to the limit switch 1, the pressing of the set pin 25 in the direction of arrow C is released, and the motor is driven to raise the electric shutter. At this time, as shown in FIG. 4B, the pinion 18 is interposed between the hour wheels 11, 12, and 13, and the hour wheels 11, 12, and 13 can be counted. The rotation is transmitted to the input shaft 7 of the limit switch 1, and the numeral wheels 11, 12, and 13 subtract in conjunction with the rise of the electric shutter.

When the electric shutter reaches the upper limit, the electric shutter cannot be raised any more, so that an overcurrent flows to the motor, and this is detected to stop the motor.
At this time, the projections 35a, 36a, 37a of the operating member 32
Is running on the peripheral surface of the numeral wheels 11, 12, and 13, the operating member 32 is rotated by the operating member 32 about the shaft 33 in the direction of the arrow E.
As a result, the operation portion 38a of the switch 38 is pressed down, and the switch 38 is turned ON.

Next, when the motor is rotated in the reverse direction to lower the electric shutter, the wheels 11, 12, and 13 are added.
As shown in FIG. 7A, the display of the numeral wheel is "999", and the electric shutter is further lowered to move the numeral wheel 1 of the first digit.
When 1 is added, the upper-order second and third digit wheels 12, 13 are carried through the carry pinion 18, and the display of all the numeral wheels 11, 12, 13 is changed to "000". Carrying operation is carried out all at once. Here, as shown in FIG. 3B, the second and third digit wheels 12, 13 are added from the first digit wheel 11 due to backlash because of the pin-on 18. Due to a slight delay, the display of these numeral wheels 12, 13 is between "0" and "1".

At this time, the second and third digit wheels 1
2, 13 are provided with recesses 40, 41 extending in the subtraction direction.
Since the recesses 41a are formed, the extended portions 40a, 41a are connected to the protrusions 36a, 3 in the same manner as the concave portion 39 of the first digit wheel 11 corresponds to the protrusion 35a of the operating member 32.
7a corresponds. For this reason, in the state of FIG. 7B immediately before the carry of the second and third digit wheels 12, 13 is completed, as shown in FIG. Since the switch 38 rotates in the direction of arrow G, the switch 38
It becomes FF, and the motor of the electric shutter stops.

At this time, the output shaft of the motor continues to rotate excessively due to the inertia of the motor itself, so that the first digit wheel 11 slightly rotates in the adding direction, as shown in FIG. In addition, the display of the first digit numeral car 11 is "0" and "1"
Stop between. The concave part 3 of the first digit numeral wheel 11
9 has an extended portion 39a formed in the addition direction.
The extending portion 39a corresponds to the projection 35a of the operating member 32, and therefore, the projection 35a
Since it does not ride on the circumference of the digit car 11 of the digit,
The electric shutter accurately stops at an arbitrary lower limit set by the limit switch 1 without malfunction of the motor.

In this embodiment, the concave portion 39 of the lowermost digit wheel 11 is extended in the adding direction to form an extended portion 39a, and the concave portions 40, 41 of the upper digit wheel 12, 13 are formed. Are extended in the subtraction direction to form extended portions 40a and 41a,
Projection 35a, 36a, 37 of each operating piece 35, 36, 37
a and the recesses 39, 40, 41 are shifted in timing, but the present invention is not limited to this.
The engagement position of the projection 35a of the operation piece 35 corresponding to the lowest digit wheel 11 of the numbers 6 and 37 with the recess 39 is shifted in the subtraction direction, and the operation piece 3 corresponding to the upper digit wheels 12 and 13 is shifted.
By displacing the engagement positions of the projections 36a, 37a with the recesses 40, 41 in the adding direction, the respective operating pieces 3
5, 36, 37 projections 35a, 36a, 37a and recess 3
The timing of engagement with 9, 40, 41 can be the same timing as in the above-described embodiment. In this case, the projections 35a, 36a,
The width of the numeral 37a in the rotating direction of the numeral wheels 11, 12, 13 is formed small, and the projections 35a, 36a, 37a and the recess 3 are formed.
If there is a play in the direction of rotation of the wheel 11, 12, 13 between the wheel 9, 40, 41, even if the wheel 11, 12, 13 rotates due to the inertia of the motor after the switch 38 is activated. The protrusions 35a, 36a,
37a does not ride on the peripheral surface of the numeral wheels 11, 12, and 13, and the switch does not malfunction.

[0028]

As described above, according to the present invention, when all the numeral wheels of a plurality of digits indicate "0", the respective operating pieces engage with the respective concave portions of the numeral wheel to activate the switch. With an actuating member, the recess of the least significant digit wheel of the plurality of digit wheels is extended in the adding direction, and the concave portion of the upper digit numeral wheel is extended in the subtracting direction. In both directions of subtraction, after the operating member engages with the concave portion of the wheel, it does not run on the peripheral surface of the wheel again, so that the switch can be operated without malfunction regardless of the rotation direction of the input shaft. Therefore, the reliability of the quality is improved.

Further, according to the present invention, when all of the numeral wheels of a plurality of digits indicate "0", each of the depressions of the numeral wheel is provided with an operation member for engaging each operation piece to operate the switch, In each of the operating pieces, the engaging position with the concave portion of the operating piece corresponding to the lowermost digit wheel is shifted in the subtraction direction, and the engaging position with the concave portion of the operating piece corresponding to the upper numeric wheel is shifted in the adding direction. In addition to shifting, the play is provided between the operating piece and the recess in the direction of rotation of the wheel so that in both directions of adding and subtracting the wheel, the operating member engages with the recess of the wheel and Since the vehicle does not ride on the peripheral surface of the vehicle, the switch can be operated without malfunction regardless of the rotation direction of the input shaft, thereby improving quality reliability.

[Brief description of the drawings]

FIG. 1 is a plan sectional view of a limit switch according to the present invention.

FIG. 2 is a sectional view taken along line II-II in FIG.

3A and 3B are side views showing a state where the limit switch according to the present invention performs a zero return operation, wherein FIG. 3A shows a relationship between a set member and a switch, and FIG. 3B shows a relationship between the set member and a zero return bracket; Is shown.

4A and 4B are side views showing a counting state of the limit switch according to the present invention, wherein FIG. 4A shows a relationship between an operating member and a switch, and FIG. 4B shows a relationship between a numeral wheel and a carry pinion.

FIG. 5 is a side view showing a state when the numeral wheel of the limit switch according to the present invention indicates “000”;
(A) shows the relationship between the operating member and the switch, and (b) shows the relationship between the numeral wheel and the carry pinion.

FIG. 6 is a diagram showing a positional relationship between a concave portion of the numeral wheel and a projection of an operating member when the numeral wheel of the limit switch according to the present invention subtracts “001” from “001”.

FIG. 7 is a diagram showing a positional relationship between a concave portion of the numeral wheel and a projection of an operating member when the numeral wheel of the limit switch according to the present invention adds “999” to “000”.

[Explanation of symbols]

1: Limit switch, 7: Input axis, 10: Counter,
11, 12, 13: Numeral wheel, 18: Carry pinion,
23: set member, 32: operating member, 35, 36, 37
... operating pieces, 35a, 36a, 37a ... projections, 38 ... switches, 39, 40, 41 ... recesses, 39a, 40a, 41
a ... Extended part.

──────────────────────────────────────────────────続 き Continued on the front page (58) Fields surveyed (Int.Cl. ⁷ , DB name) E06B 9/88 G06M 1/10

Claims (2)

(57) [Claims] 1. A multi-digit numeral wheel having a concave portion formed on a peripheral surface so that addition and subtraction can be freely performed, zero-return means for resetting these numeral wheels to zero, and all of the numeral wheels display "0". An operating member that engages each operating piece with each of the concave portions of the numeral wheel to operate the switch, wherein the concave portion of the least significant digit wheel of the plurality of numeral wheels is added in the adding direction. A limit switch characterized by extending the recess of the numeral wheel of the upper digit in the subtraction direction. 2. A multi-digit numeral wheel having a concave portion formed in a peripheral surface so as to be capable of being added or subtracted, zero-return means for resetting the numeral wheel to zero, and all of the numeral wheels display "0". An operating member that engages with each operating piece in each of the concave portions of the numeral wheel to operate the switch, wherein the concave portion of the operating piece corresponding to the lowest digit numeral wheel of the operating pieces. The position of engagement with the concave portion of the operating piece corresponding to the higher-order digit wheel is shifted in the adding direction, and the rotational direction of the numeric wheel is shifted between the operating piece and the concave portion. A limit switch characterized in that a limit switch is provided.