JPS6023361B2 - sequence switch - Google Patents

Description

[Detailed Description of the Invention] [Field of Industrial Application] This invention relates to a rotary variable resistor connected to a power supply, such as a high-resolution, long-life conductive plastic potentiometer, whose rotation angle is proportional to the rotation angle of the shaft. The output voltage that changes with the output voltage and at least one operating position setting voltage set separately from this are compared by a comparison circuit such as a differential amplifier, and an operating signal is extracted at one or more rotational positions of the shaft. The present invention relates to a sequence switch, and particularly to a sequence switch that is effectively used for sequence control of an assembly machine that operates in high cycles.

[Conventional technology]

As a sequence switch that takes out operating signals at one or more rotational positions of the shaft, a cam plate is attached to the shaft and the cam plate switches a microswitch to obtain an operating signal corresponding to the rotational position of the shaft.It is generally used as a sequence switch. .

In a sequence switch used in a continuous assembly machine with many working positions, a large number of cam plates are fixed to the shaft, and a large number of microswitches are switched according to the working sequence of each position. [Problems to be solved by the invention] However, in a sequence switch that uses a cam plate and a microswitch, failures are common due to the short life of the microswitch, and switching may be difficult due to variations in the operation of the microswitch or installation errors. Since it is difficult to achieve positional accuracy, adjustment is troublesome.Furthermore, such a sequence switch requires a large space, making it difficult to make it compact.

In particular, in order to improve accuracy, it is necessary to use a cam plate with a large diameter, so there is a problem that the sequence switch becomes even larger. It is known that such a cam plate is combined with a sliding resistance relay instead of a microswitch to primarily detect position.

It is conceivable that this can be applied to obtain an operating signal that corresponds to the rotation angle of the shaft by using the change in resistance value caused by the rotation of the rotary variable resistor's core, but such a rotating variable resistor is As shown in FIG. 1, the rotary variable resistor 1 is connected to a resistor R,
When the power supply E is connected through R2 and the shaft 4 is rotated in the direction of arrow A by a drive device (not shown), the output voltage amplified by the amplifier 5 is applied to the rotary variable resistor 1 as shown in FIG.
The effective angle between the beginning and end of the resistance a. During this period, the electrical resistance changes in proportion to the change in the rotation angle of the shaft 4, so the output voltage is proportional to the rotation angle of the shaft 4. However, in the so-called dead zone 82 between the terminal end of the resistor and the female end. As shown in the figure, an unstable output voltage is generated due to the residual resistance of the rotary variable resistor 1 and the change in contact resistance when the slider 2 and the resistor 3 come into contact with each other. Therefore, if the voltage values e,, e2, etc. are set so that the operation signal is output at the rotation angles P,, P2,..., the dead zone 82 P',, P'2,...・
The operation signal is often output even at the position of..., and the axis 4
In a sequence switch that rotates continuously,
There is a problem in that disturbances or perturbations in the output voltage in the dead zone 82 can result in malfunctions.

[Means for solving problems]

This invention was made in view of the above-mentioned problems, and includes one rotary variable resistor and a resistance that is linked to the rotation of the shaft of the variable resistor and is proportional to the rotation angle of the shaft of the variable resistor. Effective angle of resistor showing value 8. slip ring means for outputting a voltage of a predetermined level in the dead zone a2, a comparator 7 and an inverter for detecting and inverting and amplifying the output voltage of the slip ring means; 8, and a diode 9 having an anode connected to the electrical signal output side of the rotary variable resistor and a cathode connected to the inverting output side of the inverter, to suppress the unstable output of the rotary variable resistor in the dead zone 82. The diode short-circuits the voltage to a zero level, and stably maintains the level across the dead zone 82.

[Effect]

By configuring as described above, the electrical signal output in the dead zone 02 of the rotary variable resistor is an inverted output of the output voltage at a predetermined level output from the slip ring means, that is, a zero level is output from the inverter. Therefore, the electrical signal flows forward through the diode, is short-circuited, and instantaneously drops to a bell.

Since there is no output from the slip ring means in the range of effective angle 8 of the resistor other than the dead zone, the inverter outputs a high level voltage, applies a reverse voltage to the diode, and the above electrical signal output falls to zero. This prevents short-circuiting. [Embodiment] Next, an embodiment according to the present invention will be described with reference to FIGS. 3 to 5.

The rotary variable resistor 1 is provided with a slip ring means 6 that is interlocked with the rotation of the shaft 4 of the variable resistor 1, and this slip ring means exhibits a resistance value proportional to the rotation angle of the shaft 4 of the variable resistor. In the range of the effective angle of the resistor 0, the output voltage is zero, and in the range of the dead zone 82, a voltage (power supply voltage) of a predetermined level is output to the comparator 7.

The slip ring means 6 shown in FIG. 3 has a slider corresponding to the slider 2 of the variable resistor 1 fixed to rattan 4,
This is an example in which a slip ring with a conductor contact surface corresponding to the dead zone 82 between the terminal end and the starting end of the resistor is fixed to the resistor body. may be fixed to the main body side of the variable resistor.

The comparator 7 is for cutting minute noise caused by the slip ring means 6 within the range of the effective angle of the variable resistor 1 being 0. The output of the comparator 7 is applied to an inverter 8 and is inverted and amplified.

Therefore, when the output of the comparator 7 is a zero level, the output of the inverter 8 is at a high level, and when the output of the comparator 7 is a high level, the output of the inverter 8 is a level level. The electric signal outputted from the variable resistor 1 is applied to the oven amplifier 5 and amplified in a predetermined manner so that the maximum voltage is within a range slightly smaller than the high level voltage value of the inverter 8.

The amplified output of the OBE amplifier 5 is connected to the inverter 8 via a diode 9. The diode 9 has an anode connected to the amplifier 5 side and a cathode connected to the inverter 8 side, so that a forward current flows from the amplifier 5 to the inverter 8 side. Therefore, the obeamp 10 amplified by the obeamp 5
Since the output of the inverter 8 is zero in the range of the dead zone 82 and the input signal is a bell, it flows through the diode 9 and falls to the bell, so that no signal is input to the oven amplifier 10.

However, in the range of the effective angle 8 of the resistor outside the dead zone, a voltage of /. is diode 9
Since it is not possible for all the waves to flow in the same direction, an amplifier is added and amplified. Therefore, characteristics as shown in FIG. 5 can be obtained. The signals amplified from Oberampoo River are the respective operation position setting signals by comparison circuits 11, 12, . . ., e2, e3,
e4, . . . can be compared to extract the operation signal corresponding to each operation position setting signal. FIG. 4 shows an example in which a differential amplifier is used as an example of the comparison circuit 11.

The power supply voltage E is divided by variable resistors VR, VR2 to set operating position setting voltages, e.g. Setting voltage 壬2, e
, it is possible to detect a signal change and extract an operating signal that is ON or OFF only in the angular range between P2 and P within one rotation of the shaft 4 of the variable resistor. Note that reference numeral 19 is a buffer. The comparator circuit 12 has the angles P4 and P3 of the shaft 4.
The operation position setting signals e4 and e3 for switching between the two are shown in the figure, but the operation is the same as described above.

〔Effect of the invention〕

The sequence switch of the present invention configured as described above has a dead zone where the output voltage is zero in the range of the effective angle 8 of the resistor, which exhibits a resistance value proportional to the rotation angle of the shaft of the rotary variable resistor. A predetermined /・ in the range of a2
a circuit comprising a slip ring means for outputting a voltage at a high level; a circuit comprising a comparator and an inverter for detecting and inverting and amplifying the output voltage of the slip ring means; Since the unstable output of the rotary variable resistor in the dead zone 82 is reduced to zero by short-circuiting the inverted output of the rotary variable resistor, the sequence switch is This has the effect of eliminating the problem of malfunction.

In addition, the operating position can be set by adjusting the variable resistors VR, VR2, making adjustment accurate and easy.Furthermore, the output from the rotary variable resistor can be processed by an electronic circuit, and the cam plate and micro Since there is no need to use a large number of switches, an extremely compact sequence switch can be obtained. Furthermore, since there is no mechanical contact such as a microswitch, even when used in a high-cycle assembly machine, it will not break down in a short period of time, and the movement rate of the machine can be improved.

[Brief explanation of the drawing]

FIG. 1 is an explanatory diagram of a conventional technique for obtaining an output voltage proportional to shaft rotation using a rotary variable resistor, FIG. 2 is a diagram showing the output characteristics of FIG. 1, and FIG. A circuit diagram showing an embodiment of the present invention, FIG. 4, is a circuit diagram showing the comparison circuits 11, 12, .
. . . A circuit diagram showing an example, FIG. 5 is a diagram showing the output voltage characteristics of the sequence switch shown in FIG. 3. Explanation of symbols, 1... Rotating variable resistor, 5, 1
0, 15, 16...Obeamp, 6...
- Slip ring means, 7... Comparator, 8. ．．・．． ．．・Inverter, 9, 17, 18... Diode, 11, 12... Comparison circuit, 19...
···buffer. Multi 1 drawing Aoi 2 drawing ticket 4 drawing Multi 5 drawing ticket 5 drawing

Claims (1)

[Claims] 1. Converting the rotational position of the shaft of the rotary variable resistor into an electrical signal corresponding to the position, and comparing the electrical signal with at least one separately set operating position setting signal to determine one or more predetermined positions of the shaft. A sequence switch that takes out an operating signal at a rotational position of the switch, which includes one rotary variable resistor 1;
The output voltage is at zero level in the range of the effective angle θ_1 of the resistor which is linked to the rotation of the shaft of the variable resistor and has a resistance value proportional to the rotation angle of the shaft of the variable resistor, and the output voltage is at the dead zone θ.
A circuit consisting of a slipping means 6 that outputs a predetermined high level voltage in the range of _2, a comparator 7 and an inverter 8 that detect and invert and amplify the output voltage of the slipping means, and the rotary variable resistor. A diode 9 is provided with an anode connected to the electric signal output side and a cathode connected to the inverting output side of the inverter, and the unstable output of the rotary variable resistor in the dead zone θ_2 is short-circuited by the diode and lowered to zero level, and the unstable output of the rotary variable resistor in the dead zone θ_2 is A sequence switch characterized by stably maintaining a zero level over a range.