JPH08194556A - Controller for cam switch - Google Patents

Abstract

PURPOSE: To decide the allowable time according to the rotation state of a cam switch and to detect the rotation jam at the shortest detection time by counting clock pulses at the constant cycle and clearing to zero every time when the pulse signal is inverted and judging the rotation jam when the count value exceeds the allowable time. CONSTITUTION: A pulse generator outputs a pulse signal which is turned on and off every time when the cam switch which makes normal and reverse rotation is rotated at the constant rotation angle. A means 11 which decides the jam detection time decides the prescribed allowable time by the rotation commands and the pulse signal. A time measurement means 12 counts the clock pulse which is given at the constant cycle and clears to zero every time when the pulse signal is inverted. A rotation jam discriminating means 13 judges the rotation jam when the count value of the means 12 exceeds the allowable time. Thus, the allowable time is properly decided according to the rotation state of the cam switch and the rotation jam is detected at the shortest detection time.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a cam switch control device, and more particularly to an improved cam switch control device capable of detecting rotation congestion of a cam switch.

[0002]

2. Description of the Related Art Cam switches are used in a wide range of fields, such as switching circuits depending on the rotation angle and outputting various control signals. The operation motor controls the rotation angle to control the main circuit. There is a cam switch for switching.

This type of cam switch may be provided with a device for detecting a rotation congestion. Hereinafter, a conventional portion for detecting a traffic congestion will be described. FIG. 4 shows a main part mechanism of this type of cam switch. In FIG. 4, reference numeral 1 denotes a rotary shaft of a cam switch, and a cam (not shown) coupled to the rotary shaft 1 switches a main circuit in accordance with a rotation angle and controls a main electric motor (not shown) so as to control an intermediate rotation angle. Is set to a stop position and rotated left and right to control the controlled object to move forward and backward. 2 is the rotating shaft 1
An operating electric motor for rotating 3 is a plurality of cams that are coupled to the rotating shaft 1 to rotate, and 4A to 4D are limit switches that operate at a predetermined rotation angle by the plurality of cams 3, respectively.
Reference numeral 5 is a pulse generator that outputs a predetermined pulse signal according to the rotation angle of the rotating shaft 1, and 6 is a pulse generator 5.
Is a rotation congestion detector that detects the rotation congestion of the cam switch from the output signal of.

FIG. 5 shows a control circuit for driving the operating motor 2. In FIG. 5, reference numeral 7 denotes an operation switch for operating the cam switch. When stopped, 7C-7D is closed, forward is closed 7A-7B, and backward is closed 7E-7F. Reference numerals 8 and 9 are electromagnetic switches.

Limit switches 4A-4D are shown in FIG. 6 (a).
As shown in FIG. 5, the limit switch 4 operates in a predetermined rotation angle range according to the rotation angle of the rotation shaft 1 of the cam switch.
A is closed in the range from just before the forward limit to the reverse limit, limit switch 4B is closed in the range from the reverse limit to just before the stop position, and limit switch 4C is closed in the range from just before the reverse limit to the forward limit. However, the limit switch 4D closes in the range from the forward limit to just before the stop position.

Therefore, when the operation switch 7 is selected to stop, the circuit between 7C and 7D is closed, and the limit switches 4A and 4B are closed.
Alternatively, the electromagnetic switch 8 or 9 is excited via the limit switches 4C and 4D, the operating motor 2 is rotated in the forward or reverse direction, and the rotary shaft 1 of the cam switch is controlled to the stop position. Further, when the operation switch 7 is selected to be forward or reverse, 7A-7B or 7E-7F is closed, the electromagnetic switch 8 or 9 is excited through the limit switch 4A or 4C, and the operation motor 2 is normally rotated. Alternatively, the rotation is reversed, and the rotary shaft 1 of the cam switch is driven at a predetermined rotation speed to a position just before the forward limit or just before the backward limit.

As described above, when moving from the stop position to the position just before the forward limit or just before the backward limit, the main circuit switched by the cam switch does not have the capacity for continuous energization and has a short-term rating (for example, a control resistor). Etc.)
If the traffic jam occurs, the article will be burned and must be stopped within the allowable time.

As shown in FIG. 6 (b), the pulse generator 5 outputs the signals CH1 to CH4 according to the rotation angle of the rotary shaft 1 of the cam switch, and the signal CH1 is ON at the forward limit and the signal CH1 is ON.
CH2 is on in stop position, signal CH3 is on in reverse limit, signal C
H4 is turned on every fixed rotation angle range (eg 10 °).
Outputs signals that turn off.

The rotation congestion detector 6 is composed of a microcomputer or the like, takes in the auxiliary contacts of the electromagnetic switches 8 and 9 and these signals CH1 to CH4 output from the pulse generator 5 and performs the processing of the flowchart shown in FIG. To detect traffic congestion. That is, with the electromagnetic switch 8 or 9 turned on, the signal CH1 indicates that the position is not in the forward limit, stop, or reverse limit.
~ When CH3 is confirmed, it is determined that the rotary shaft 1 is rotating, the timer counter is cleared to zero, and the count of clock pulses given at regular intervals is made a star, and the count value is monitored. Since the timer counter is cleared to zero every time the value of the signal CH4 is inverted, the count value does not exceed the allowable time when the cam switch is rotating normally. When the rotation congestion occurs due to some reason, the time until the value of the signal CH4 is inverted is extended and the count value of the timer counter exceeds the allowable time, so that it is determined that the rotation congestion occurs.

[0010]

However, in the above-described method for determining the rotational congestion, the allowable time is uniformly set according to the longest case of the moving time of the rotary shaft so as to prevent erroneous detection. There is a problem that the time for detecting is longer than necessary, which may cause a delay in the linked protection operation. That is, since the signal CH4 is turned on / off in each fixed rotation angle range (for example, 10 °), the allowable time is set to the maximum time for moving the fixed rotation angle, and the start time, constant speed movement time, and stop time are set. It is set by the total time which added time.

As described above, since the allowable time is uniformly set according to the case of the longest movement time of the axis, the traffic jam detection time becomes longer than necessary, which may cause a delay in the interlocking protection operation and the like, which may cause a problem. Occurs.

The present invention has been made in view of the above problems, and an object thereof is to appropriately determine an allowable time in accordance with a rotation state of a cam switch and to detect a rotation congestion with a minimum detection time. It is to provide a control device for the provided cam switch.

[0013]

According to the invention of claim 1,
A cam switch that switches the circuit according to the rotation angle, an electric motor that rotates the cam switch forward and reverse in response to a forward rotation and reverse rotation command, and on / off each time the cam switch rotates a fixed rotation angle. A pulse oscillator for outputting a pulse signal, a traffic jam detection time determining means for determining a predetermined allowable time by the forward / reverse rotation command and the pulse signal, and counting the clock pulses given at a constant cycle and the pulse There are provided time measuring means for zero-clearing each time the signal is inverted, and rotation congestion determining means for determining rotation congestion when the count value of the time measuring means exceeds the allowable time.

As a second aspect of the present invention, the traffic jam detection time determination means further includes a time T1 during which the cam switch moves a constant rotation angle at the rotation speed when the electric motor is rotating at a constant speed. Then, when the electric motor is rotated from the stopped state, the moving time T1 is added to the starting time T2 for accelerating the electric motor from zero speed to the constant speed.

According to a third aspect of the present invention, the traffic jam detection time determining means further includes: when the electric motor rotates at a constant speed and reverses midway, the counting time of the time measuring means at that time.
Tc is held, and the value is determined by adding the start time T2 and the counting time Tc to the stop time T3 for decelerating the electric motor from the constant speed to zero speed.

[0016]

According to the first aspect of the present invention, when the electric motor rotates the cam switch in the normal or reverse direction in response to the forward or reverse command, the pulse transmitter causes the cam switch to rotate at a constant rotation angle. A pulse signal for turning on / off is output, and the traffic jam detection time determination means determines a predetermined allowable time based on the forward / reverse rotation command and the pulse signal. Further, the time measuring means counts clock pulses given at a constant cycle and is cleared to zero each time the pulse signal is inverted, and the rotation congestion judging means determines that the count value of the time measuring means exceeds the allowable time. Judging to be a traffic jam.

According to a second aspect of the present invention, the traffic jam detection time determination means determines that the electric motor is rotating at a constant speed when the forward rotation and reverse rotation commands are continuously given for a predetermined time or more, Determined by the time T1 during which the cam switch moves a certain rotation angle at the rotation speed, and when the forward rotation / reverse rotation command is given from the state where the forward rotation / reverse rotation command is not given for a predetermined time or longer, the electric motor is stopped. It is judged that it will rotate from
The value is determined by adding the starting time T2 to the time T1.

According to a third aspect of the present invention, the traffic jam detection time determining means is configured such that, when a forward rotation or reverse rotation command is continuously given for a predetermined time or more and the command is reversed, the electric motor rotates at a constant speed and is in the middle. When it is judged that the rotation is reversed, the counting time Tc of the time measuring means at that time is held, and the value is determined by adding the stop time T3 and the starting time T2 to the counting time Tc.

[0019]

FIG. 1 shows the structure of an embodiment corresponding to claims 1 to 3 of the present invention. FIG. 1 shows the configuration of the main part.
Determines and outputs the shortest detection time of the rotation congestion of the cam switch as the allowable time T0 from the signals of the auxiliary contacts of the switches 8 and 9 and the output signals CH1 to CH4 of the pulse generator 5, and resets the time measuring means 12. A traffic jam detection time determining means for outputting a signal for counting the number of clock pulses (not shown), and an output signal CH of the pulse generator 5.
Each time the value of 4 is inverted, it is cleared to zero, and is reset to zero by the reset signal output from the congestion detection time determining means 11. The time measuring means 13 is a counter, and 13 is the count value (counting time Tc) of the time measuring means 12. It is a traffic congestion determination means that determines that the traffic congestion occurs and outputs a detection signal when the permissible time T0 output from the traffic congestion detection time determination means 11 is exceeded. Others are the same as the conventional ones.

Each of these means can be constructed by using a microcomputer or the like, and a concrete example of the signal processing will be described with reference to the waveform diagram of FIG. 2 and the flowchart of FIG.

FIG. 2 shows the output signal CH of the pulse generator 5.
4 shows the relationship between the count value of the counter and the allowable time for judging traffic jam. (A) shows the cam switch rotating at a constant speed in a certain direction, and (b) shows the cam switch The case where the rotation direction is reversed in the middle is shown.

The signal CH4 has a constant rotation angle range (for example, 1
A signal that turns on / off every 0 °) is output, the count value of the counter increases in proportion to the time, and it is cleared to zero each time the value of the signal CH4 reverses, and when the allowable time T0 is exceeded, there is a rotation congestion. To be judged. The traffic jam detection time determining means 11 determines the allowable time according to the change of the operation mode, and when the cam switch is rotating at a constant speed in a constant direction as shown in FIG. When the shortest movement time T1 for rotating within a certain rotation angle range (for example, 10 °) at speed is set as the allowable time, and the rotation direction of the cam switch is reversed midway as shown in FIG. 2 (b), The count value Tc of the counter at the reversal time tx is held in the memory, and the value obtained by adding the stop time t3 and the start time t2 of the motor to the value Tc is set as the allowable time T0. Although not shown in FIG. 2, when the cam switch is rotated from the stopped state, a value obtained by adding the activation time T2 to the shortest movement time T1 is set as the allowable time T0.

The flow chart of FIG. 3 illustrates one embodiment for performing these things. First, the control flags F1 to F4 are initialized to 0, the states of the switches 8 and 9 are checked, and when both are open, the process returns to the standby state. In this case, the control flag F1 is set to 1 when the standby state continues for a predetermined time or longer.

When the switch 8 is closed, the control flag F2 becomes 1
When the control flag F1 is set to 1 and it is determined that the motor starts from the stopped state, the allowable time T0
Is determined as a value obtained by adding the starting time T2 to the time T1 during which the cam switch moves at a constant rotation angle at a constant rotation speed. When the control flag F1 is 0, the control flag F3 is further checked. If the control flag F3 is 0, it is determined that the electric motor is rotating at a constant speed, and the allowable time T0 is determined as the moving time T1. When the control flag F3 is set to 1, it is determined that the rotation direction of the electric motor is reversed, the count time Tc of the counter at that time is held in the memory, and the allowable time T0
Is determined as a value obtained by adding the stop time T3 and the start time T2 to the counting time Tc, and the counter is cleared to zero. After that, the signals CH1 to CH output from the pulse generator 5
Confirm that the rotation position of the cam switch is not in the forward limit, stop, or reverse limit by 3 and start counting the counter. On the other hand, when the signal CH4 output from the pulse generator 5 moves within a certain rotation angle range (for example, 10 °), the value is inverted and the counter value is cleared to zero. If it exceeds T0, it is determined to be a traffic jam. The same process is performed when the switch 9 is closed. As described above, since the allowable time of the moving time according to the rotation state of the cam switch is determined, it is possible to detect the rotation congestion in the minimum detection time.

[0025]

According to the present invention, the rotation congestion can be detected in the minimum detection time according to the rotation state of the cam switch, and the interlocking protection operation can be performed quickly, and the peripheral equipment It is possible to provide a rotary traffic jam detecting device which can obtain the same effect as the conventional one.

[Brief description of drawings]

FIG. 1 is a configuration diagram of an embodiment corresponding to claims 1 to 3 of the present invention.

FIG. 2 is a waveform diagram for explaining the operation of the present invention.

FIG. 3 is a flowchart for explaining the operation of the traffic jam detection time determination means 11 of the above embodiment.

FIG. 4 is a schematic diagram of a cam switch to which the present invention is applied.

FIG. 5 is an operation circuit of a cam switch to which the present invention is applied.

FIG. 6 is a diagram for explaining the operation of the output signals CH1 to CH4 of the limit switches 4A to 4D and the pulse generator 5 of FIG.

FIG. 7 is a flowchart for explaining the operation of the conventional rotation congestion detection device.

[Explanation of symbols]

1 ... Rotary shaft of cam switch 2 ... Electric motor 3 ... Cams 4A to 4D ... Limit switch 5 ... Pulse generator 6 ... Rotation jam detector 7 ... Operation switch 8,9 ... Electromagnetic switch 11 ... Traffic jam detection time determining means 12 ... Time Measuring means 13 ... Congestion judging means

Claims (3)

[Claims] 1. A cam switch for switching a circuit in accordance with a rotation angle, an electric motor for rotating the cam switch in a normal or reverse direction in response to a forward or reverse rotation command, and the cam switch for rotating a constant rotation angle. A pulse oscillator that outputs a pulse signal that turns on and off every time, a traffic jam detection time determination unit that determines a predetermined allowable time by the forward rotation and reverse rotation commands and the pulse signal, and a clock pulse given at a constant cycle. Time counting means for counting and zero-clearing each time the pulse signal is inverted, and rotation congestion determining means for determining rotation congestion when the count value of the time measuring means exceeds the allowable time are provided. Cam switch control device. 2. The cam switch control device according to claim 1, wherein the traffic jam detection time determining means, when the electric motor is rotating at a constant speed, rotates the cam switch at a constant speed at the rotating speed. Determined by the time T1 to move the corner, when the electric motor rotates from the stopped state, the start time for the electric motor to accelerate from zero speed to the constant speed
A control device for a cam switch, which is determined to be a value obtained by adding the moving time T1 to T2. 3. The cam switch control device according to claim 2, wherein the traffic jam detection time determining means determines the counting time of the time measuring means at the time when the electric motor rotates at a constant speed and reverses midway. Control of the cam switch, which holds Tc, and determines a value obtained by adding the starting time T2 and the counting time Tc to a stop time T3 for decelerating the electric motor from the constant speed to zero speed. apparatus.