JPH0864073A - Limit switch - Google Patents

Abstract

PURPOSE: To obtain a limit switch which can carry out the setting of an accurate timing, by providing a switch lever to transmit a signal by fitting to a recess formed at the periphery of a digit wheel of the highest level figure after the whole figures of the digit wheel is lowered. CONSTITUTION: When a reset shaft is operated to rotate, a dowel 55a is fluctuated in the direction B so as to rotate a driven lever 41 in the direction C, the engaging surface 43a of an arm 42 presses a pinion shaft 34, a return bracket 28 is rotated in the direction D so as to press a heart cam 21b by a pressing piece 29, and a highest level figure digit wheel 21 and the like is returned to a specific value all at once. At the same time, the engaging part 41a of the driven lever 41 is rotated in the direction E so as to press the engaging projection 37c of a switch lever 37, and the switch lever 37 is rotated forcibly in the direction F. As a result, the lever part 37a is not fitted to the recess 21a of the digit wheel 21 during the specific value return operation, the operating rod 47a of a microswitch 47 is not turned OFF, and an accurate timing of setting can be carried out.

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 upper and lower limits or upper and lower limits of a shutter or the like.

[0002]

2. Description of the Related Art A limit switch of this type is disclosed in Japanese Patent Publication No. 52-44004.
To explain this outline, a multi-digit decimal accumulator tachometer and a control member that sends out a pulse when the display of the highest digit of the accumulator tachometer shifts from "0" to "9". A pair of counters provided are connected so as to rotate in reverse to each other, one counter is reset to zero at the upper limit of the shutter, and the other counter is reset to zero at the lower limit of the shutter. The upper and lower limits of the shutter are set.

[0003]

However, in the conventional range setting limit switch described above, when the pulse transmission timing is changed from "0" to "9" on the display of the highest digit digit, that is, " 000 "to" 9 "
It will be carried out after the total digit reduction to "99" all at once.
Since the operation is performed at "000" displayed by the zero return operation for setting the upper limit and the lower limit of the shutter, there is a deviation of "1" for both. Therefore, the stop position at the upper and lower limits of the shutter will stop at positions above and below the set position by an amount that is incremented by the "1" number counter, resulting in an extra load on the motor. However, there was a problem that the reaction to stop was delayed.

Therefore, the present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to set a set numerical value and a signal generation timing to be the same, and thus to set an accurate timing. To provide limit switches.

[0005]

In order to achieve this object, a limit switch according to the present invention is provided with a numeral wheel having a plurality of digits and a carry for interposing the numeral wheels to carry the numeral wheel. A pinion, a specific value restoring means for returning the numeral cars to a specific value all at once, and a signal is transmitted by fitting into a concave portion formed on the peripheral surface of the numeral car of the highest digit after total digit reduction of the numeral cars. In a limit switch provided with a switch lever, the specific value is a numerical value after total digit reduction. Further, the limit switch according to the present invention includes a pair of limit switches, and the limit wheels are connected so as to rotate in reverse.

[0006]

According to the present invention, the signal from the highest digit numeral wheel is transmitted at the set value set by the specific value restoring means. Further, according to the present invention, the range is set by the two limit switches.

[0007]

An embodiment of the present invention will be described below with reference to the drawings. 1 to 8 show a limit switch according to the present invention, FIG. 1 is an overall exploded perspective view, FIG. 2 is a plan view, FIG. 3 is a front view, FIG. 4 is an exploded perspective view of a counter section, and FIG. 2 is a sectional view taken along the line VV in FIG. 6, and FIG. 6 is a view in the direction VI of FIG. 2 showing the relationship between the highest digit car and the switch bracket,
FIG. 7 is a sectional view taken along line VII-VII in FIG. 2, and FIG. 8 is a circuit configuration diagram adopted in the shutter opening / closing mechanism.

In these drawings, a range setting limit switch indicated by reference numeral 1 as a whole is a body frame 2, a counter section 3 consisting of a pair of first limit switch 4 and second limit switch 5, a drive shaft section 6 and It is composed of a reset shaft portion 7, and these can be disassembled and assembled as a single unit. The main body frame 2 includes a pair of disc-shaped side plates 10, 10, a partition plate 11 located in the center of the side plates 10, 10, connecting plates 12, 12 for connecting the side plates 10, 10 and a bottom plate. 1
3 and 3. A pair of fitting grooves 14 is formed in the center of the upper edges of both side plates 10, 10 and two pairs of fitting grooves 15, 15 are formed in the lower edges. 16 is a notch formed at the center of the upper edge of the partition plate 11, and 17 is the bottom plate 1.
The holes 18 and 18 (see FIG. 3) formed in the reference numeral 3 are bearing portions formed on the back surface of the bottom plate 13.

First and second limit switches 4, 5
Is composed of a numeral wheel unit 20 and a control unit 21, and both counters 4 and 5 have the same structure. Hereinafter, only the first limit switch 4 will be described. The number wheel section 20 has heart cams 21b and 2 on the sides, respectively.
Three numeral wheels 2b and 23b are formed, that is, a hundreds digit numeral wheel 2 in which a concave portion 21a is provided at a predetermined peripheral surface position.
A 1st and 10th digit numeral wheel 22 and a 1st digit numeral wheel 23 are coaxially and rotatably supported together with a feed gear 24 on a shaft 25 horizontally extending between both side plates of a frame 26. Numbers such as a normal counter are not attached to the peripheral surfaces of these numeral wheels 21 to 23, but a decimal system is adopted, and a numeral wheel of a lower digit advances 10 steps by a pinion 33 for carry which will be described later. Then, the upper digit number wheel is configured to make one step, and hereinafter, for convenience of description, it is assumed that the same numbers as those of an ordinary counter are attached to the peripheral surfaces of the number wheels 21 to 23. To do.

Reference numeral 28 denotes a return bracket, which is integrally formed with three heart cam pressing pieces 29 for pressing the heart cams 21b, 22b and 23b, and pins 30 projecting from both side surfaces.
Is fitted to a U-shaped bearing portion 32 integrally formed on the bottom surface portion of the frame 26, and is swingably supported by the bearing portion 32. Reference numeral 33 is a carry-up pinion, which is rotatably supported by a pinion shaft 34 horizontally projecting at both ends of both sides of the return bracket 28, and is supported by a coil spring 31 axially mounted on a pin 30 to return the bracket 2.
8 is oscillated and urged, so that the carry-in pinion 33
Is meshed with the segment gears on the side surfaces of the numeral wheels 21, 22, and 23 and the driving gear 24, and when the rotation is transmitted to the feed gear 24 from the outside, every one rotation of the first digit numeral wheel 23,
The tens digit car 22 is carried up by one step through the carry pinion 33.

Reference numeral 36 denotes a frame having a U-shaped cross section, which is used to attach the numeral wheel portion 20 to the frame 36 by screwing a hole 36a screwed to the bottom surface portion 13 of the main body frame 2 with a screw 35 and the frame 26. The hole 36b is formed and the rectangular hole 36c is formed.
37 is a shaft 3 which is horizontally mounted on both side portions of the frame 36
A switch lever rotatably supported by 8 and having a curved lever portion 37 a that abuts on the peripheral surface of the hundreds digit numeral wheel 21, and a first lever attached to a side surface portion of the frame 36.
An operating portion 37b for operating the operating rod 47a of the micro switch 47 and an engaging projection 37c protruding from the other end side are provided. Normally, as shown in FIG. 6 (a), the lever portion 37 a abuts on the peripheral surface of the hundreds digit numeral wheel 21, and the operating portion 37 a
The operating rod 47a of the micro switch 47 is turned on by b, and when the hundreds-digit numeral wheel 21 displays "9", the concave portion 21a is moved to the lever portion 37 as shown in FIG.
At the position a, the lever portion 37a fits into the recess 21a, so that the operating rod 47a is released from the operating portion 37b, and the OF
The state becomes the F state. A second micro switch 48 having the same configuration as the first micro switch 47 is also provided in the second limit switch 5. Reference numeral 40 denotes a return drive bracket which is swingably supported by a shaft 45 horizontally extending on both side portions of the frame 36, and includes a pair of opposed arm portions 42.
Is provided, and the arm 42 has the pinion shaft 3
The groove 43 which engages with both ends of 4 is formed.

A driven lever 41 is provided at one end of the return drive bracket 40 so as to project therefrom.
1, an engaging portion 41a with which the engaging protrusion 37c of the switch lever 37 is engaged is projected. Reference numeral 44 denotes a dowel 41b of the driven lever 41, one end of which is inserted into the shaft 45.
The other end is a coil spring that is hooked on the cut-and-raised pieces 46 of the frame 36 to give the return drive bracket 40 a rotational habit. 5A, the return drive bracket 40 has a habit of rotating in the direction A about the shaft 45, and one engagement surface 43a of the recess 43 of the return drive bracket 40 has a pinion shaft. 34 by pressing the return bracket 28
The rotation habit is imparted in the clockwise direction (direction A) about the shaft 30. With such a configuration, even when the carry pinion 33 receives an impact from the outside, the carry pinion 33 is prevented from coming off the numeral wheel 21, and the character shift or the like is prevented. On the other hand, in a specific value returning operation described later, the other engagement surface 43b of the recess 43 engages with the pinion shaft 34.

The drive gear 5 to which the rotation transmission from the outside, for example, the rotation of the rotating body which is interlocked with the opening and closing of the shutter, is transmitted to one end of the drive shaft 50 constituting the drive shaft portion 6.
1 is fitted and a pair of transmission gears 52, 5 meshing with the respective feed gears 24 of the counters 4, 5.
3 is fitted, and the drive shaft 50 has a drive gear 51.
The counters 4 and 5 are driven in common by being rotationally driven from the outside via.

The reset shaft portion 7 is provided with a pair of a first reset shaft 8 and a second reset shaft 9, and one ends 8a and 9a of these reset shafts 8 and 9 are formed in a D-cut shape. The reset levers 55, 56 are provided with engaging projections 55a, 56a on the other end side, which are in contact with the driven lever 41 of the return drive bracket 40 of the first and second limit switches 4, 5, respectively. Is fitted. Reference numeral 57 is a coil spring fitted into the reset shafts 8 and 9, one end of which is hung on the reset levers 55 and 56, and the other end of which is hung on the back surface of the bottom surface portion 13 of the main body frame 2.
A turning habit is given to 5, 56. These first and second
In the reset shafts 8 and 9, the levers and the like (not shown) are fixed to the ends 8a and 9a in a direction orthogonal to the reset shafts 8 and 9, and the levers are individually pulled to rotate about the axis. Then, the numeral wheels 21 to 23, which will be described later, are simultaneously returned to the specific value.

Next, a method of assembling the range setting limit switch having such a structure will be described. First, the body frame 2
Two counters 4 with a partition plate 11 on the bottom surface 13 of the
2, the counter plates 5 are arranged symmetrically with the partition plate 11 sandwiched therebetween, and the center lines of the counters 4 and 5 connect the fitting grooves 14 and 14 of the main body frame 2 with each other. It is fixed to the frame with screws 35 so as to match g. After that, the drive shaft 50 is fitted into the fitting groove 14 and fixed. At this time, since the g-g line and the center lines of both counters 4 and 5 coincide with each other, the transmission gears 52 and 53 mesh with the feed gears 24 and 24 of both counters 4 and 5. And
When the drive gear 51 rotates in the normal direction, the feed gear 24 of the counter 4 rotates in the normal direction, while the feed gear 2 of the counter 5 rotates.
Since 4 rotates in reverse, both counters 4 and 5 rotate in reverse. As described above, since the counters 4 and 5 are rotated in the opposite directions by the rotational drive of the single drive shaft 50 and via the pair of transmission gears 24, the number of parts is reduced and The structure can be simplified and the size can be reduced.

Next, the coil spring 57 is fitted into the reset shafts 8 and 9, and one end of the coil spring 57 is hooked on the reset levers 55 and 56, and one end of the coil spring 57 is a bearing portion on the back surface of the bottom surface portion 13 of the main body frame 2. The reset shafts 8 and 9 are rotatably supported on the back surface of the bottom surface portion 13 by fitting the reset shafts 8 and 9 into the fitting groove 15 at the other end. Reset levers 5 of supported reset shafts 8, 9
5, 56 penetrate through the hole 17 of the body frame 2 and the hole 36c of the frame 36 of the counter to face the inside of the counters 4 and 5, and as shown in FIG.
The dowels 55a and (56a) of 6) are engaged with the driven lever 41 of the return drive bracket 40.

In such a structure, when the reset shaft 8 is rotated, the dowel 55a swings in the B direction as shown in FIG.
5 in the clockwise direction (C direction), and by this rotation, the other engagement surface 43b of the recess 43 of the arm portion 42 presses the pinion shaft 34, and the return bracket 28 with the shaft 30 as the center. Since it is rotated in the counterclockwise direction (D direction), the pressing piece 29 moves the heart cams 21b to 23b.
By pressing, the numeral wheels 21 to 23 are returned to the specific value all at once. In the present embodiment, when this specific value is subtracted by one digit, all the digits are subtracted, so that the total digit is reduced, that is, "999" is obtained by subtracting one digit from "000". When this specific value returning operation is performed, at the same time, as shown in FIG. 7, the engaging portion 41a of the driven lever 41 rotates in the E direction and engages with the engaging protrusion 37c of the switch lever 37, so that the switch lever Since 37 is forcibly rotated in the counterclockwise direction (F direction) about the shaft 38, the concave portion 21a is located at the lever portion 37a of the switch lever 37 during this specific value returning operation. Part 3
7a does not fit into the recess 21a, so that the operating rod 47a of the microswitch 47 does not turn off.

FIG. 8 is a circuit diagram of the range setting limit switch 1 for setting the upper and lower limits of the shutter when the shutter is opened and closed. In the figure, 60
Is an AC motor whose forward / reverse rotation is switchable, 61 is a motor changeover switch for switching forward / backward rotation of the AC motor 60 to raise / lower a shutter (not shown), 62 is an AC motor 60 and a motor changeover switch AC1 connected to 61
It is a power source of 00V. The first micro switch 47 is A
Between the C motor 60 and the “lower” terminal of the motor changeover switch 61, and the second micro switch 48 is between the AC motor 60 and the “upper” terminal of the motor changeover switch 61.
Each intervenes.

Next, the operation of setting the upper limit and the lower limit of the shutter by using the range setting limit switch 1 having such a configuration will be described mainly based on FIG. 8 and Table 1.

[0020]

[Table 1]

First, in order to set the lower limit position of the shutter, the motor selector switch 61 is operated to switch to the "lower" terminal so as to lower the shutter, and at the same time, the first reset shaft 8 is rotated and operated. The numeral wheel of the first limit switch 4 is returned to a specific value, that is, "999". At this time, as shown in FIG. 7, the switch lever 37 in which the engagement protrusion 37c is engaged by the engagement portion 41a of the return drive bracket 40 rotated by the dowel 55a is moved to the F-position.
Since the first micro switch 47 is turned in the direction, the first micro switch 47 is forcibly turned on by the operating portion 37b of the switch lever 37, the AC motor 60 is activated, and the shutter is lowered. During this period, the first limit switch 4 is driven in the subtraction direction, but since the first reset shaft 8 is continuously rotated, the first limit switch 4 is set to “999”.
It remains. When the descending shutter reaches the lower limit, the rotation operation of the first reset shaft 8 is released. At this time, the first limit switch 4 is "999".
Is still displayed and the lever portion 37a of the switch lever 37 is fitted into the recess 21a as shown in FIG. 6B, the first macro switch 47 is turned off, and A
The C motor 60 stops. During this time, the second limit switch 5 is added to display an arbitrary numerical value.

Next, in order to set the upper limit position of the shutter, the motor changeover switch 61 is operated to switch to the "upper" terminal so as to make the shutter upper limit, and at the same time, the second reset shaft 9 is rotated. , The number wheel of the second limit switch 5 is returned to a specific value, that is, “999”. At this time, as in the case of setting the lower limit position described above, the second
The micro switch 48 is forcibly turned on by the operating portion 37b of the switch lever 37, so that the AC motor 60 is activated and the shutter is raised. During this time, the second limit switch 5 is driven in the subtraction direction, but the second limit switch 5 remains at "999" because the second reset shaft 9 is continuously rotated. Then, when the rising shutter reaches the upper limit, the rotation operation of the second reset shaft 9 is released. At this time, the second
The limit switch 5 of the switch lever 37 remains displaying "999", and the lever portion 37a of the switch lever 37 is
Since it fits into the recess 21a as shown in (b), the second macro switch 48 is turned off and the AC motor 60 is stopped. During this period, the first limit switch 4 is added to display the numerical value corresponding to the rise of the shutter, that is, "050" in this embodiment.

Next, the control operation of the shutter after setting the upper and lower limits of the shutter in both counters 4 and 5 will be described. Now, when the shutter is located at the upper limit, the first limit switch displays "050" and the first micro switch 47 is in the ON state. When the motor selector switch 61 is switched to the "lower" terminal, A
When the C motor 60 is activated and the shutter starts to move downward to reach the lower limit position, the display of the first limit switch 4 displays “9”.
99 ”, the first micro switch 47 is turned off, the AC motor 60 is stopped, and the shutter is stopped at the set lower limit position. Here, the shutter is the above-mentioned first
"999" set to the lower limit position by the limit switch 4 of
Since it stops at "999" in the same display as, the precision of the stop position becomes the same as the set position, and it becomes possible to control at an accurate position. Therefore, the reaction of the shutter stop becomes accurate, and the AC No unnecessary load is applied to the motor 60 or the like. At this time, the second limit switch 5 displays "050", and the second micro switch 48 is O.
It is in the N state.

Next, in order to raise the shutter from the lower limit position to the upper limit position, the motor selector switch 61 is switched to the "up" terminal. The AC motor 60 is activated, the shutter is raised, and at the same time, the display of the second limit switch 5 is changed to "0.
50 "is subtracted. When the shutter reaches the upper limit position, the display of the second limit switch 5 becomes "999", the second micro switch 48 is turned off, and the AC
The motor 60 stops and the shutter stops at the set upper limit position. Here, the shutter stops at "999" with the same display as "999" set to the upper limit position by the second limit switch 5 as in the case of stopping at the lower limit position described above, so the accuracy of the stop position is set. It is the same as the position.

In the present embodiment, a pair of counters 4 and 5 in which the numeral wheels rotate in opposite directions are provided so that both the upper limit and the lower limit of the shutter can be set. It goes without saying that either the upper limit or the lower limit may be set.

[0026]

As described above, according to the present invention, a plurality of digit cars, a carry pinion for performing a carry operation of the digit cars interposed between these digit cars, and the digit cars are simultaneously provided. Limit switch provided with a specific value returning means for returning to a specific value, and a switch lever for transmitting a signal by fitting into a recessed portion on the peripheral surface of the highest-order digit vehicle after the total digits have been lowered. The specific value set by the operation of the specific value restoring means is the total digit that is the timing of the signal transmitted from the highest-order digit wheel, by setting the specific value to a value after total digit reduction. Since it coincides with that after lowering, there is no difference between the set value and the timing of signal transmission, and therefore, the controlled member can be controlled accurately and quickly.

Further, according to the present invention, the limit switches are paired and coupled so that the respective numeral wheels are rotated in reverse, so that the switch levers of both limit switches allow the controlled member to have a specified range. It is possible to repeatedly control and to improve the control function.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a limit switch according to the present invention.

FIG. 2 is a plan view of a limit switch according to the present invention.

FIG. 3 is a front view of a limit switch according to the present invention.

FIG. 4 is an exploded perspective view of a counter in the limit switch according to the present invention.

5 is a sectional view taken along line VV of FIG.

FIG. 6 is a VI arrow view showing the relationship between the hundreds digit vehicle and the switch lever in FIG. 2.

7 is a sectional view taken along line VII-VII of FIG.

FIG. 8 is a circuit configuration diagram in which a limit switch according to the present invention is used to open and close a shutter.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Range setting limit switch, 4 ... 1st limit switch, 5 ... 2nd limit switch, 8 ... 1st reset shaft, 9 ... 2nd reset shaft, 21 ... 100-digit digit wheel, 21a ... Recessed part , 21b ... Heart cam, 28
... Return bracket, 29 ... Heart cam pressing piece, 33 ... Carry-on pinion, 34 ... Pinion shaft, 36 ... Frame, 37 ... Switch lever, 37a ... Lever part, 37
b ... operating part, 40 ... return drive bracket, 41 ... driven lever, 47 ... first micro switch, 48 ... second micro switch, 50 ... drive shaft, 52 ... first transmission gear, 53 ... second Transmission gear, 55 ... first reset lever, 56 ... second reset lever, 60 ... AC motor, 61 ... motor changeover switch, 62 ... power supply.

Claims (2)

[Claims] 1. A multi-digit numeral wheel and a carry pinion for interposing the numeral wheel to carry the numeral wheel.
Specific value returning means for returning the numeral cars to a specific value all at once, and a switch lever for transmitting a signal by fitting into a concave portion formed in the peripheral surface of the numeral digit car of the highest digit after total digit reduction of the numeral cars. A limit switch provided with and wherein the specific value is a numerical value after total digit reduction. 2. The limit switch according to claim 1, wherein a pair of limit switches are provided, and the limit switches are connected so as to rotate in reverse.