JPH0438295Y2 - - Google Patents

Description

[Detailed Description of the Invention] <Technical Field> The present invention relates to a pulse type rotational speed switch which is suitable for use in detecting, for example, the idling rotational speed, overspeed rotational speed, etc. of an engine and obtaining a contact output.

<Prior art> Conventionally, as shown in FIG. 1, a rotational speed switch has a movable flyweight 3 attached to a rotating shaft 2 mechanically connected to a rotating body 1, which is an object to be detected. There is a device in which limit switches 7 and 8 are actuated via a sleeve 5 and a lever 6 in accordance with the centrifugal force of the actuator.

However, since such a rotation speed switch has a mechanical structure, it has the following drawbacks.

Since mechanical connection is required, there are restrictions on where it can be installed.

To set the detection rotation speed, rotate the rotation axis (actually rotate the detected object).
It is necessary and difficult to adjust.

Since it involves mechanical movement, the response is slow (detection response time is long).

The accuracy of the detected rotation speed is low (only rough adjustments and settings are possible).

<Purpose of the invention> Therefore, the purpose of this invention is to be able to install it separately from the object to be detected, with fewer restrictions on installation location, space, etc.
Furthermore, the set rotation speed can be preset arbitrarily according to the usage conditions, there is no need to rotate the object to be detected, and it can be used without adjustment.Furthermore, the pulse type has high detection accuracy and fast detection response speed. The purpose is to provide a rotation speed switch.

<Configuration of the invention> In order to achieve the above object, the pulse type rotation speed switch of this invention includes a digital switch for setting the number of pulses for setting the number of unit pulses corresponding to one revolution of the rotating body, and a pulse number setting digital switch for setting the number of unit pulses corresponding to one revolution of the rotating body. The digital switch for setting the detection rotation speed to set the specific rotation speed of the body and the synchronization pulses that are synchronized with the rotation of the rotating body input from the pulse sensor are counted every unit time, and this counted value is calculated as the above unit pulse number. Divide by
a processor that outputs division result data and outputs an on/off signal by comparing the division result data with the specific rotational speed; a decoder that decodes the division result data to display it digitally; and a decoder that decodes the division result data to display it digitally. A converter that converts data into an analog signal for analog display;
The present invention is characterized in that it includes a relay that is driven by the on/off signal.

<Example> Hereinafter, this invention will be explained in detail with reference to illustrated examples.

In Fig. 2, 11 is an engine, 12 is a rotating body such as a camshaft gear of the engine 11 and an auxiliary drive gear, 13 is a pulse sensor that outputs a synchronizing pulse synchronized with the rotation of the rotating body 12, and 15 is a pulse sensor. A pulse-type rotation speed switch is placed at a location away from the sensor 13 and receives synchronized pulses from the pulse sensor 13. 16 is for setting the number of pulses for setting the number of unit pulses corresponding to one revolution of the rotating body 12. Digital switches 17, 18, and 19 are detection rotation speed setting digital switches for setting respective rotation speeds of the rotating body 12 corresponding to overspeed, specified speed, and low speed, and 21, 22, and 23 are relays;
4 is an engine control monitoring panel.

As shown in FIG. 3, the pulse type rotational speed switch 15 includes a processor 32 (hereinafter referred to as CPU). A synchronizing pulse from the pulse sensor 13 is waveform-shaped by a waveform shaping circuit 31 and input to the CPU 32 . In addition, the CPU 32 has
A digital signal representing the unit pulse number corresponding to one revolution of the rotating body 12 is inputted from the pulse number setting digital switch 16 . As a result, the number of unit pulses corresponding to one rotation is, for example, 2 to 2.
It is set over a wide range of 499 pieces. Further, the CPU 32 receives a digital signal representing the rotation speed corresponding to the overspeed from the detection rotation speed setting digital switch 17, and a digital signal representing the rotation speed corresponding to the specified speed from the detection rotation speed setting digital switch 18. and a digital signal representing a rotation speed corresponding to a low speed such as idling, for example, is inputted from a digital switch 19 for setting the detected rotation speed.

The CPU 32 counts the synchronization pulses input from the waveform shaping circuit 31 every unit time, and divides this count by the number of unit pulses to calculate the rotation speed of the rotating body 12. The CPU 32 outputs a signal representing the rotational speed to a digital display 34 via a decoder 33 to display the rotational speed in decimal form, and outputs a signal representing the rotational speed to a digital display 34 to display the rotational speed in decimal form. Output to a total of 36,
The above rotation speed is displayed in analog form.

Further, the CPU 32 compares the calculated rotation speed with a signal representing overspeed inputted from the detection rotation speed setting digital switch 17, and when the rotation speed exceeds the overspeed rotation speed, the CPU 32 outputs a relay signal. 21
A signal is output to turn on the normally open contact 21', thereby activating the protection device of the engine control and monitoring panel 24 shown in FIG. Furthermore, the above CPU32
compares the calculated number of rotations with a signal representing the number of rotations at a specified speed inputted from the digital switch 18 for setting the detection number of rotations, and activates the relay 22 if the number of rotations exceeds the number of rotations at the specified speed. Output a signal to turn on, turn on the normally open contact 22',
The engine control monitoring panel 24 displays that the specified rotation speed has been reached. Further, the CPU 32 compares the calculated rotational speed with a signal representing the low speed rotational speed inputted from the digital switch 19 for detecting rotational speed setting, and determines if the rotational speed exceeds the low speed rotational speed. , turn on relay 23 and normally open contact 23'
is turned on to display on the engine control and monitoring panel 24 that the engine speed has reached a low speed.

In this way, the rotational speed of the rotating body 12 is detected by digitally processing the synchronizing pulses from the pulse sensor 13 by the CPU 32, so that the detection accuracy is high and the detection response speed is quick. Further, in this way, the engine 11 is provided with only the pulse sensor 13, and the pulse type rotational speed switch 1
5 can be placed separately from the engine 12, and the pulse type rotational speed switch 15 itself has no mechanical parts.
Since it is small, there are fewer restrictions on the installation location and space of the rotation speed switch 15. In addition, this pulse type rotation speed switch 15 uses a digital switch for setting the number of pulses with a wide setting range to set the optimum number of unit pulses according to the number of rotations to be detected. Regardless of the rate of occurrence, the generated pulses are sent directly to the CPU.
32, the rotation speed can be detected with high precision, making it highly versatile for pulse sensors. Furthermore, digital switches 17, 18,
19, the set rotation speed can be preset according to the usage conditions, so there is no need to rotate the rotating body 12 to adjust it during use, and the CPU 32
The on/off signal that is the comparison result between the set rotation speed and the measured rotation speed can drive an alarm device, etc. via the relays 21, 22, 23, and the measured rotation speed can be converted into digital data via the decoder 33 and converter 35. , analog display is possible, and it is highly versatile for display and alarm devices. Furthermore, since the pulse type rotational speed switch 15 has no mechanical parts, it has fewer failures and has a long life.

In the above embodiment, three relays are provided, but any number of relays may be provided to output on/off signals for any number of set values. In addition, as in the above embodiment, calculation of the rotation speed,
Comparison, output, etc. can not only be achieved by a CPU, but can also be implemented by logic circuits such as counting by a counter and comparison by a comparator.

Note that 37 is a mode setting switch, 38 is a voltage regulator, and 39 is a voltage monitoring device.

<Effects of the invention> As is clear from the above explanation, the pulse type rotational speed switch of this invention is constructed as described above, so it is compact and can be installed separately from the rotating body, saving space and installation space. There are few restrictions, and the unit pulse number and specific detection rotation speed can be preset arbitrarily using a digital switch, making adjustment easy.Also, since the rotation speed is detected by digital processing, detection accuracy is high and detection response speed is high. It has various advantages, such as being fast, having no moving parts, having a long lifespan with few failures, and being highly versatile for display and alarm devices.

[Brief explanation of drawings]

FIG. 1 is a sectional view of a conventional rotational speed switch, FIG. 2 is an explanatory diagram of an embodiment of this invention, and FIG. 3 is a block diagram of the above embodiment. 13...Pulse sensor, 15...Pulse type rotation speed switch, 32...CPU, 16...Digital switch for setting the number of pulses, 17, 18, 19
...Digital switch for setting detection rotation speed, 21,
22, 23...Relay.

Claims (1)

[Scope of utility model registration request] a digital switch for setting the number of pulses for setting the number of unit pulses corresponding to one revolution of the rotating body;
The detection rotation speed setting digital switch for setting the specific rotation speed of the rotating body to be detected and the synchronization pulses that are synchronized with the rotation of the rotating body input from the pulse sensor are counted every unit time, and this counted value is A processor that divides by the above unit pulse number and outputs the division result data, and also outputs an on/off signal by comparing the division result data with the above specific rotation speed, and digitally displays the above division result data. A pulse type rotational speed switch comprising: a decoder for decoding the division result data, a converter for converting the division result data into an analog signal for analog display, and a relay driven by the on/off signal.