JPH0319136Y2 - - Google Patents

Description

[Detailed description of the invention] [Field of industrial application] The invention is applicable to limit switches for opening/closing control and opening control used in large valves in chemical plants, river water gates, and other opening/closing devices. The present invention relates to an adjusting device which is used for exchanging a limit switch and can accurately transfer the limited operating point set in an old limit switch to a new limit switch when exchanging the limit switch.

[Prior Art] The adjustment of the limiting operating point of a conventional limit switch is carried out on-site while actually operating the valve or sluice gate, depending on the operating environment of the valve or sluice gate. This is done by adjusting the fully open operating point and, if necessary, adjusting the intermediate operating point at an appropriate opening halfway between fully closing and fully opening.

The appropriate limiting operating point for fully closing and fully opening large valves and water gates, etc. varies slightly depending on the inherent inertia of the drive control system, including the valve body or the motor that drives the gate, etc. The rotation angle and stroke from fully closed to fully open of the water gate have their own dimensions for each individual valve and water gate, and furthermore, the opening degree of the valve or water gate that is input to the limit switch installed at the appropriate location in the drive system The ratio between the proportional deflection amount and the actual amount of movement of the valve body or the gate itself varies depending on the usage status of the valve or water gate, and even if it is fully closed or fully open, the ratio between the amount of proportional deviation and the actual amount of movement of the valve body or the gate itself varies. etc., it is difficult to set it in advance.

[Problem to be solved] The setting of the limit operating point of a conventional limit switch is
It is determined by the actual opening/closing position of the valve or gate to be controlled. Therefore, when replacing the electrical contacts of the limit switch currently in use due to wear, the new limit switch must be set to the appropriate limit while test driving the valves and gates for re-adjustment. There is a problem in that the operating point must be reset.

However, for valves used in operating chemical plants, test runs for replacing limit switches are virtually impossible.

In addition, many similar limit switches are used in chemical plants and the like, and the operation of the chemical plant cannot be stopped each time they are replaced.

Additionally, there are some dam flood gates that cannot be tested for opening and closing.

Furthermore, the operating limit point of the opening of a valve or water gate, which is set midway between fully closed and fully opened, has been empirically selected as the optimal operating point based on long-term use of chemical plants and waterways. This is often the operating point, and conventionally it has been difficult to reset the limiting operating point that has been set in this way.

[Means for solving the problem] In the present invention, a limit switch that requires replacement and a limit operating point set in advance, and a limit switch that is reset by transferring the setting value of the limiting operating point set in the limit switch. A new limit switch,
a limit switch attachment part that can be installed in a freely replaceable manner; a deviation amount generating means that is connected to an operating deviation input part of the limit switch attached to the limit switch attachment part and provides a desired amount of deviation to the limit switch; a deviation amount measuring means connected to the deviation amount generating means to measure the amount of deviation generated by the deviation amount generating means; and a display for numerically displaying the amount of deviation measured by the deviation amount measuring means. means, a deflection operating means for respectively controlling the forward direction deflection drive, reverse direction deflection drive, and stop of these drives of the deflection amount generating means, and connected to any one of the limiting contacts of the limit switch, The above problem is solved by providing a limited contact opening/closing display means for displaying the opening/closing state of the contact.

[Embodiment] FIGS. 1 and 2 show an embodiment of a limit switch motion point adjusting device according to the present invention.

The main body 1 of the adjusting device is housed in a trunk case 2 for convenient portability, and after opening the lid 2a, a limit switch 4 is attached to the top panel 3 of the main body 1.

The old limit switch 4 that needs to be replaced is first installed, and the operating points of fully closed, fully opened, and at each limit in between are measured, and then a new limit switch 4 is installed. The previously measured limit motion points are adjusted and set.

Mounting part 5 of limit switch 4 on main body 1
In order to easily replace the old one with a new one, the limit switch 4 is attached to the main body 1 via the attachment plate 6 of the limit switch 4, which is detachable from the body 1.
is now ready to be installed.

Two mounting plates 6 are usually prepared to facilitate replacement, and only the mounting plate 6 is installed in advance on both the old limit switch 4 and the new limit switch 4, and then attached to the main body 1. When installed, it is fixed with a set screw 7.

This mounting plate 6 is designed to fit the mounting hole 6a of the limit switch 4, the center position of the actuation deviation input section 8, and the input section of the limit switch 4 in accordance with a specific model out of a large number of models depending on various uses of the limit switch 4. The diameter of the hole 6b passing through the hole 6b is determined, and the hole 6b serves as a jig member for positioning the mounting.

By attaching the limit switch 4 to the panel 3 of the main body 1 via the mounting plate 6 of this jig member, its operating deviation input section 8 is connected to the deviation amount generating means 9 built into the main body 1. be done.

The limit switch 4 shown in the embodiment is a multi-rotation intermittent gear feed type as shown in FIGS.
The input gear 8b at the tip of the input gear 8b meshes with the output gear 10 of the motor 9a, which serves as a deviation amount generating means 9 for generating rotational deviation for performing the limiting operation.

The output of the motor 9a is a rotation consisting of an output gear 10, an intermediate gear 11 meshing with the output gear 10, a pivot 12 thereof, a bevel gear 13 provided at one end of the pivot 12, a bevel gear 14 meshing with the bevel gear 13, a pivot 15 thereof, and a coupling 16. It is transmitted to the deviation amount measuring means 18 via the transmission mechanism 17.

The deviation measuring means 18 measures the amount of rotational deviation of forward rotation and reverse rotation generated by the motor 9a.

The deviation amount measuring means 18 is a multi-rotation counter 18a.
The multi-rotation deviation measured by the deviation measuring means 18 is displayed on the upper panel 3 of the main body 1 using an appropriate numerical display means 19.

For example, when the rotation counter 18a is a mechanical decimal value rotation display gear counter, the numerical display part 19a of the rotation counter 18a is fitted into the window hole 3a provided in the top panel 3, and the rotation counter The amount of rotation measured by 18a is displayed numerically.

Another example of the deviation amount measuring means 18 may be an electronic counter using an absolute or incremental rotary encoder. In that case, the numerical display section of the electronic counter will
A numerical display means 19 is provided on the upper panel 3.

The motor 9a is operated by a suitable power source, for example, either a battery-powered DC power source or a commercial AC power source.

Positive deflection drive, reverse deflection drive, and stopping of the limit switch 4 generated by the motor 9a is performed by the deflection operating means 2 provided on the top panel 3.
0, for example, controlled by a forward rotation drive switch 20a, a reverse rotation drive switch 20b, and a drive stop switch 20c.

Furthermore, a limit switch 4 is installed on the top panel 3.
A limited opening/closing display means 22 is provided for displaying the open/closed state of each limiting contact 21 that opens and closes in limited mode according to the amount of deviation when the contact point 21 is positively or reversely deflected.

For example, the limited contact opening/closing display means 22 includes an appropriate number of display lamps 22a, 22b, 22c, 22d,
It consists of a lamp drive circuit (not shown) that drives each of the lamps 22a to 22d to blink, a cord 23 that connects the lamp drive circuit to each of the limiting contacts 21 of the limit switch 4, and a connector 24.

As in the embodiment, it is more convenient to provide a large number of indicator lamps 22a to 22d depending on the number of limited operating points that the limit switch 4 can set. Since there is only one limiting unit, one limiting contact 21
It may be used while changing the connection each time.

On the top panel 3, there is an automatic-manual switch for selecting either a mode in which the motor 9a is automatically driven or a mode in which the motor 9a is manually driven in conjunction with the power switch 24 and the required limiting contact 21. A switch 25 is provided.

3 to 7 show an example of the limit switch 4 for controlling valve opening/closing used in the present invention. Hereinafter, based on these figures, the limit operation and its adjustment procedure will be briefly explained.

An input shaft 8a of the input section 8 of the limit switch 4 is provided with a drive gear a for driving a plurality of limiting units Ac to Ao.

As shown in Figures 3 and 5, drive gear a is fitted with two upper and lower intermediate gears b, b, shafts c and c fixed to intermediate gear b, and non-rotatable around the axis of shaft c. It is connected to four limited-acting units Ac, Ax, Ay, and Ao via unit drive gears d and d, which are installed in the axial direction and can be freely retracted and retracted in the axial direction.

Each limiting unit Ac to Ao has the same structure,
Further, the intermittent feed gear mechanism used in each of the limiting units Ac to Ao is the same as the intermittent carry mechanism in a well-known decimal rotation counter or the like.

Below, one of the limited units Ac will be briefly explained.

The unit drive gear d meshes with the continuous teeth of the first-stage multi-toothed gear e' in the intermittent feed mechanism B, and
Drive the intermittent feed mechanism B.

The intermittent feed mechanism B consists of a multi-toothed gear e, which has continuous teeth on one side (left side in Figure 3) and one intermittent tooth with a valley on the other side (right side in Figure 3), which are coaxially connected in multiple stages. An intermittent feed gear f is provided between the stages of each multi-tooth gear e, and meshes with the intermittent teeth on the lower stage side and the continuous teeth on the upper stage side.

The uppermost intermittent feed gear f' is connected to a switch shaft h provided with a movable contact g of a switch unit C, and drives the shaft h intermittently.

The intermittent feed gear f consists of four teeth, and the intermittent teeth of the intermittent feed gear f and the multi-tooth gear e mesh with each other.
When one feed is completed, the intermittent feed gear f
rotates 90 degrees, and in the final stage, the switch shaft h
Rotate 90 degrees.

Four movable contacts g are provided on the switch shaft h, penetrating the axis h at right angles, and each of the movable contacts g is divided into two pieces, with their penetrating directions perpendicular to each other. .

A fixed contact piece i provided with inward elasticity is provided corresponding to each movable contact g so as to sandwich the switch shaft h.

Any two of these four sets of fixed contact pieces i are short-circuited by the movable contact g and are in the switch ON state, and the other two sets are in the switch OFF state and the switch is ON. , the OFF state is reversed when feed is applied to the final stage intermittent feed gear f′.

As described above, each of the limiting units Ac to Ao, when the input shaft 8 rotates in the forward direction or reverse direction from the gear position corresponding to the input shaft 8 in the respective intermittent feed mechanism B, The switch shaft h rotates to reverse the ON/OFF state of the switch, and the rotational speed of the input shaft 8 from the time when the input shaft 8 starts rotating is determined as the limited operating point.

In addition, the limiting action point of any one of the limiting units Ac to Ao is used as a reference point, and the other limiting units Ac
The forward rotational speed or reverse rotational speed up to the operating point of ~Ao is the relative limit operating point set for the limit switch 4.

The relative operating points of the limiting motion of each of the limiting units Ac to Ao can be freely adjusted by once disconnecting the input shaft 8 from each of the limiting units Ac to Ao.

That is, the unit drive gear d is pushed in the axial direction by the push screw j to disengage the first-stage multi-tooth gear e' of the intermittent feed mechanism B, thereby freeing the first-stage multi-tooth gear e'.

The multi-toothed gear e' in the first stage is fixed to the rotating shaft k of the gear e', and the rotating shaft k has a notch in the shaft end so that it can be turned from the rear with a screwdriver, etc., as shown in Fig. 6. It extends to the rear end.

Limited-acting unit Ac separated from input shaft 8
By rotating the first-stage multi-tooth gear e′ in the forward or reverse direction, Ao
The limited motion point relative to Ao can be changed.

FIG. 6 shows the relative relationship between the limit operating points when the above-mentioned limit switch 4 is used to control the opening and closing of a valve, and the adjustment procedure will be explained below based on this diagram.

For conventional adjustment, limit switch 4
When the valve is in use for controlling the valve, the valve opening/closing mechanism and the input shaft 8 are connected.

First, push in unit drive gears d and d with push screws j, and push each limited drive gear A to Ao.
After disconnecting the input shaft 8a, the opening degree of the valve body is set to fully closed, or slightly just before fully closed, taking into account the inertia of the drive mechanism when the valve is closed. At that time, the fully closed limited unit operates only when fully closed.
Rotate the first-stage multi-tooth gear e′ of Ac to adjust the switch state to turn ON or OFF.

Next, set the opening degree of the valve body to full open or slightly before full open, and at that full open point, the full open limiter
Adjust the switch status of Ao to switch between ON and OFF.

The fully closed limited unit Ac adjusted in this way,
The relative relationship between the limiting operating points of the fully open limiting unit Ao is as follows:
The rotation speed of the input shaft 8 is always set to a constant rotation speed.

That is, if the fully closed point is 0 rotations, then N rotations, for example 200 forward rotations, will lead to the fully open limit operating point, and 200 reverse rotations from the fully open point will result in the fully closed point.

On the way from fully closed to fully open, the limiting operating points of the intermediate limiting units Ax and Ay are adjusted and set as appropriate depending on how the valve is used. This operating point is changed as appropriate.

Therefore, it is often unclear to what value the limiting operating points of the intermediate limiting units Ax and Ay are adjusted when the limit switch 4 is replaced. 4 is difficult to replace.

As described above, when the limit switch 4, which has been adjusted to each limited operating point, is replaced with a new limit switch 4 due to contact wear etc., each limited operating point set in the old limit switch 4 is to a new limit switch 4 with high reproducibility.

The procedure for transferring the limiting operating point of the old limit switch 4 to the new limit switch 4 will be explained below.

First, remove the old limit switch 4 that needs to be replaced by checking the current stop position of the limit contact from the valve body. A mounting plate 6 corresponding to the above is attached, and the old limit switch 4 is also attached to the main body 1 of the adjustment device via the mounting plate 6.

In the adjustment device, a limit switch 4 and a motor 9a are connected, and the motor 9a is rotated in the forward direction.
Or by rotating it in the opposite direction, each limiting unit Ac, Ax,
The limiting operating points of Ay and Ao are found, and the amount of input deviation between the limiting operating points is counted by the rotation counter 18a.

In this case, the input rotation speed of the limit switch 4 and the count value of the rotation counter 18a do not necessarily have to be in a 1:1 relationship;
It is sufficient if the resolution of 8a is higher.

Further, the reference point for zero clearing the revolution counter 18a may be the limited operating point at the time when the old limit switch 4 is removed, or may be at either the fully closed or fully open position, but the reference point (0 point) is the point at which both limit switches Let's make them correspond to each other.

The limiting operation point is confirmed by connecting the cord 23 to any of the contacts of each of the limiting units Ac to Ao and checking the blinking of the indicator lamps 22a to 22d.

The rotation counter 18a is read by reading the value displayed on the numerical display section 18a when any of the display lamps 22a to 22d turns on or off.

The value of each limited motion point read in this way
Nc, Nx, Ny, and No correspond to those set in the old limit switch 4, as shown in FIG.

Next, replace the limit switch 4 with a new one.

Regarding the new limit switch 4, the count value of each limited operating point measured by the old limit switch 4
For each of Nc, Nx, Ny, and No, the corresponding limiting units Ac, Ax, Ay, and Ao can be adjusted by attaching them to the valve body so that they operate in limiting action.
Adjust in the same manner.

The new limit switch 4 adjusted in this way has each of the limiting operating points set in the old limit switch 4 accurately transferred, and when the old limit switch 4 is removed from the valve body, Attach the valve to the valve body, aligning it with the confirmed fully closed, fully open, or intermediate operating point.

[Effects] As described above, according to the present invention, each limit operating point set in a limit switch whose electric contacts are worn out and needs to be replaced can be accurately transferred to a new limit switch. It is easy to replace the limit switch, and the reliability of the control system after the limit switch is replaced is high.

In addition, since the device of the present invention can be easily made portable as in the embodiment, it can be replaced at the site where a limit switch that requires replacement is used, and the work of relocating the limit operating point can be carried out. It is easy and more efficient than re-adjusting the valve while it is attached to the valve body, and the time required for replacement is shorter, so it can be done quickly and safely without stopping the operation of the valve body's control system. The limit switch can be replaced.

[Brief explanation of the drawing]

FIG. 1 is a perspective view of a limited motion point adjusting device showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line -- in FIG. 1, and FIGS. An example of a limit switch used in the device is shown. FIG. 3 is a central vertical sectional side view of the limit switch, FIG. 4 is a plan view of FIG. 3, and FIG. 5 is a rear view of the limit switch. FIG. 6 is an operation diagram showing the opening/closing operation of each limiting action unit and the limiting opening/closing contact of each unit of the limit switch shown in FIG. 3. DESCRIPTION OF SYMBOLS 1... Main body of adjustment device, 2... Trunk case, 2a... Lid, 3... Top panel, 3a... Window hole, 4... Limit switch, 5... Mounting part, 6... Mounting plate, 6a... ...Mounting hole, 6b...
Hole, 7... Set screw, 8... Operational deviation input section, 8
a...Input shaft, 8b...Input gear, 9...Deflection amount generating means, 9a...Motor, 10...Output gear,
11... Intermediate gear, 12... Pivot, 13... Bevel gear, 14... Bevel gear, 15... Pivot, 1
6... Coupling, 17... Rotation transmission mechanism, 1
8... Deflection amount measuring means, 18a... Rotation counter, 19... Numerical display means, 19a... Numerical display section, 20... Deviation operation means, 20a... Forward rotation drive switch, 20b... Reverse rotation drive Switch, 20c
... Drive stop switch, 21 ... Limiting contact, 22
...Limited opening/closing display means, 22a, 22b, 22
c, 22d...Display lamp, 23...Code, 2
4...Power switch, 25...Auto-manual changeover switch, a...Tribe gear, b, b...Intermediate gear, c...Shaft, d...Unit drive gear,
e, e'...multi-tooth gear, f, f'...intermittent feed gear,
g...Movable contact, h...Switch shaft, i...Fixed contact piece, j...Press screw, rotating shaft...k, A...
Limiting unit, Ac... Totally closed limiting unit, Ao...
... Fully open limit unit, Ax, Ay... Intermediate limit unit, B... Intermittent feed mechanism, C... Switch unit.

Claims (1)

[Scope of utility model registration request] A limit switch mounting part that can replaceably install a limit switch whose limiting operating point has been set in advance and needs to be replaced, and a new limit switch that has been reset by transferring the setting value of the limiting operating point set to the limit switch. and a deflection amount generating means connected to the operating deflection input section of the limit switch attached to the limit switch mounting portion to provide a desired deflection amount to the limit switch; a deviation amount measuring means for measuring the amount of deviation generated by the deviation amount generating means; a display means for numerically displaying the amount of deviation measured by the deviation amount measuring means; and the deviation amount generating means. A deflection operating means for controlling forward deflection drive, reverse deflection drive, and stopping of these drives, respectively, and a limit switch connected to one of the limiting contacts of the limit switch and displaying the open/closed state of the contact. 1. A limit operation moving point adjusting device for a limit switch, comprising a moving contact opening/closing display means.