JPH0791982A - Handheld tachometer - Google Patents

Abstract

(57) [Abstract] [Purpose] Even if the rotating speed of the object to be measured is low in a handheld tachometer that is both contact and non-contact
The contact type enables accurate measurement, and the contact type and non-contact type can be automatically used. [Structure] A light emitting / receiving unit 3, a non-contact type rotation detection system 4, and a contact type rotation detection system 6 are provided in a case 2, and a large number of detection pulses are output per one rotation of a rotating shaft 14 rotated by contact. As described above, a large number of light reflectors 32 constituting the light reflection chopper 25 are attached along the rotation direction thereof, and at the same time, contact type detection means 34 for detecting the presence or absence of rotation of the rotary shaft 14 and rotation detection by this means 34. With or without
A configuration is provided that includes a calculation unit 36 that calculates the rotation speed of the DUT by changing the calculation coefficient of the rotation speed of the DUT, and a display 38 that displays the calculation result of the calculation unit 36.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a handheld tachometer which is both contact type and non-contact type.

[0002]

2. Description of the Related Art Generally, there are two types of handheld tachometers, one is a contact type in which a contact is pressed against an object to be measured and the rotational speed of the object is read, and the other is a reflection at one or more points of the object. There is a non-contact type in which the object to be measured is irradiated with light with the seal attached and the rotational speed of the object to be measured is read from the change in light intensity caused by the presence or absence of a reflective seal.

The former contact type has an advantage that the rotational speed can be directly read directly by only contacting the object to be measured, but on the other hand, when the rotational torque of the object to be measured is small or the object to be measured rotates. There is a drawback that the rotation speed cannot be measured in a dangerous place.

On the other hand, the latter non-contact type has a characteristic contradictory to the contact type, and since it can measure even at a position away from the object to be measured, it can be used in a place where safety is required, Although it is possible to measure the rotating torque of the object to be measured, it is difficult to easily measure the rotating speed of the object to be measured.

Therefore, in the prior art, there is provided a handheld tachometer which can be used both as a contact type and as a non-contact type so as to make up for the drawbacks of the both (for example, Japanese Utility Model Publication No. 57-179164). (See gazette).

In this apparatus, a non-contact type handheld tachometer is used as a main body, and a contact type adapter is detachably attached to the main body. When the adapter is attached to the main body, the adapter is contact type When removed from, use as a non-contact type.

However, the conventional handheld tachometer of this type requires an adapter to be attached to and detached from the main body every time it is selectively used as a contact type or a non-contact type, which is extremely troublesome to handle.

Therefore, the inventors of the present invention have provided a handheld tachometer which can be used as it is without contacting with an adapter or attaching or detaching a contact-type tachometer, which is used as a contact-type or a non-contact type. 4-178175).

[0009]

The present inventors further studied this handheld tachometer, and found that the light reflection chopper fixed to the contact type rotating shaft has only one pulse per one rotation of the rotating shaft. Since it does not occur, it has been found that the following problem occurs especially when the rotational speed of the measured object is low.

In other words, when using as a non-contact type, if the number of reflective seals to be attached to the object to be measured is increased,
Since many pulses can be obtained per one rotation of the measured object even when the rotational speed of the measured object is low, accurate measurement results can be obtained even if the measurement time is short. However, when used as a contact type, since only one pulse can be obtained per one rotation of the object to be measured, accurate measurement results cannot be obtained unless the measurement time is long, and a long time is required for measurement.

The present invention has been made to solve the above-mentioned problems, and even when the rotational speed of the object to be measured is low,
To be able to accurately measure the rotation speed of the contact type, and to automatically use the contact type and the non-contact type without switching the internal signal processing circuit. Is an issue.

[0012]

The present invention adopts the following constitution in order to solve the above problems.

That is, the handheld tachometer according to the present invention includes a light emitting / receiving section, a non-contact type rotation detecting system,
And a contact-type rotation detection system.The non-contact-type rotation detection system irradiates the object to be measured with light from the light emitting and receiving unit, and guides the reflected light from the object to the light emitting and receiving unit again. And a light passage opening is formed in the case at a position intersecting with the optical axis of the optical means, and the contact-type rotation detection system is arranged substantially parallel to the optical axis of the optical means. It has a rotating shaft, and one end side of this rotating shaft is projected to the outside of the case, and a contactor for contacting the object to be measured is attached to this protruding part. A light reflection chopper that intermittently reflects the light from the light emitting and receiving unit along with the rotation of the shaft is fixed, and this light reflection chopper is configured by mounting a large number of light reflectors along the rotation direction thereof, Contact-type detection means for detecting the presence or absence of rotation of the rotary shaft, A calculation unit that changes the calculation coefficient of the rotation speed of the measured object according to the presence or absence of rotation detection by the detection unit and calculates the rotation speed of the measured object based on the detection pulse output from the light emitting and receiving unit. And a display for displaying the calculation result by the calculation unit.

[0014]

When used as a non-contact type, the light from the light emitting / receiving unit is applied to the object to be measured by the optical means, and the reflected light from the object to be measured is again transmitted / received via the optical means. The light is received by the unit, and a detection pulse having a frequency corresponding to the rotation speed of the measured object is output. In this case, since the contactor that constitutes the contact type rotation detection system is not in contact with the object to be measured, the rotating shaft does not rotate, so that there is no detection output of the contact type detection means. Therefore, the calculation unit calculates the number of revolutions of the object to be measured based on the detection pulse from the light projecting / receiving unit by using a non-contact calculation coefficient.

In the case of using the contact type, when the contact is pressed against the object to be measured, the rotary shaft to which the contact is attached rotates, so that the light reflection chopper fixed to the rotary shaft is thrown accordingly. The light from the light receiving portion is intermittently reflected. Then, the reflected light is received by the light emitting / receiving unit, and a detection pulse having a frequency corresponding to the rotation speed of the object to be measured is output. In this case, since the rotating shaft is rotating, the detection output from the contact-type detecting means is given to the arithmetic unit, and a large number of detection pulses corresponding to the number of light reflectors are provided for each rotation of the rotating shaft. Since it is output, the calculation unit employs a contact-type calculation coefficient to accurately calculate the rotation speed of the measured object based on the detection pulse from the light emitting and receiving unit.

[0016]

1 is an overall configuration diagram of a handheld tachometer according to an embodiment of the present invention, and FIG. 2 is a front view of a light reflection chopper portion.

The handheld tachometer 1 of this embodiment is
In the case 2, a light emitting / receiving unit 3, a non-contact type rotation detection system 4 and a contact type rotation detection system 6 are provided.

The light projecting / receiving section 3 is composed of a light emitting element 8 such as a light emitting diode and a light receiving element 10 such as a phototransistor which are arranged close to each other.

The non-contact type rotation detection system 4 irradiates the object to be measured with light from the light projecting / receiving section 3 and a lens as an optical means for guiding the reflected light from the object to be measured again to the light projecting / receiving section 3. 12 is provided, and a light passage opening 2a is formed at a position where the optical axis x of the lens 12 intersects with the case 2. Incidentally, a sealing glass may be provided in the light passage opening 2a, or the lens 12 may be directly attached.

On the other hand, the contact type rotation detection system 6 includes a lens 12
The optical axis x has a rotation axis 14 which is displaced by a predetermined distance from the optical axis x and is substantially parallel to the optical axis x.
The rotating shaft 14 is rotatably supported by being inserted through both the pair of bearings 15 and 16 and the spacers 18 for restricting the positions of the two bearings 15 and 16, and has a large diameter provided in the intermediate portion of the rotating shaft 14. The portion 14a and the stop ring 20 prevent the bearings 15 and 16 from coming off, and a compression spring 19 is interposed between the large-diameter portion 14a and the bearing 15 to slide along the axial direction. It is movably installed. Further, one end side of the rotary shaft 14 is
A contactor 21 that is brought into contact with an object to be measured is fitted into the case 2 by penetrating a rotary shaft insertion hole 2b formed in the case 2 and protruding to the outside of the case 2. This contact 21
Is configured by attaching a conical rubber cap 23 to the tip of a cylindrical plug 22 whose idle rotation is restricted by a pin 24. A light reflection chopper 25, which intermittently reflects the light from the light emitting / receiving unit 3 as the rotation shaft 14 rotates, is fixed to the other end of the rotation shaft 14 with a screw 28. As shown in FIG. 2, the light reflection chopper 25 includes a large number of reflection seals 32 (four in this example) as light reflectors along the rotation direction of the disk 30 fixed to the rotation shaft 14 with screws 28. It is configured by pasting.

Further, in this example, a micro switch 34 as a contact type detection means for detecting the presence or absence of rotation of the rotary shaft 14 constituting the contact type rotation detection system 6 is provided, and the micro switch 34 faces the screw 28. It is located in a position. That is, in order to use the contact-type rotation detection system 6,
When the contact 21 comes into contact with the rotating non-measurement object, the rotary shaft 14 rotates in response to the contact, and the rotary shaft 14 is pushed in the axial direction to turn on the micro switch 34. The presence or absence of rotation of the rotary shaft 14 is detected by turning on / off the micro switch 34.

Further, in the case 2, based on the light reception signal output from the light emitting / receiving unit 3, the calculation coefficient of the rotation speed of the object to be measured is changed according to the presence / absence of rotation detection by the micro switch 34. A calculation unit 36 that calculates the rotation speed of the object to be measured, and L that displays the calculation result of this calculation unit 36.
A display device 38 such as a CD is provided.

When the handheld tachometer 1 having the above structure is used as a non-contact type, the light emitting / receiving section 3 and the non-contact type rotation detecting system 4 are used.

That is, when the light emitting element 8 of the light emitting / receiving unit 3 is turned on, the light passes through the lens 12 and the light passage opening 2a of the case 2 and is irradiated toward an object to be measured (not shown). As the DUT rotates, the reflective sticker attached to the DUT also rotates at the same time, and when the reflective sticker reaches the position that crosses the optical axis x, the reflected light is reflected. After passing through the passage opening 2a and passing through the lens 12,
The light is received by the light receiving element 10. Thereby, the light receiving element 10
Outputs a detection pulse having a frequency corresponding to the rotation speed of the object to be measured.

In this case, since the contactor 21 constituting the contact type rotation detection system 6 is not in contact with the object to be measured, the rotary shaft 14 does not rotate, and the microswitch 34 pushes the rotary shaft 14 in the axial direction. There is no detection output because it is not performed. Therefore, the calculation unit 36 determines that the contact 21 is in the non-contact state and the rotary shaft 14 is not rotated,
The rotation speed of the object to be measured is calculated based on the detection pulse output from the light receiving element 10 of the light projecting / receiving unit 3 by using a contact / non-contact calculation coefficient. Then, the calculation result is displayed on the display 38 of the next stage.

When used as a contact type, the light emitting / receiving unit 3 and the contact type rotation detecting system 6 are used.

That is, when the contactor 21 is pressed against the rotating object to be measured after the light emitting element 8 of the light emitting / receiving unit 3 is turned on, the rotary shaft 14 is rotated together with the contactor 21. Then, as the rotary shaft 14 rotates, the reflective seal 32 attached to the disk 30 also rotates at the same time, and the light is reflected every time the reflective seal 32 crosses the luminous flux from the light emitting element 8. The reflected light is received by the light receiving element 10. As a result, the light receiving element 10 outputs a detection pulse having a frequency according to the rotation speed of the object to be measured.

Moreover, when the contact 21 is pressed against the object under rotation, the rotary shaft 14 slightly slides in the right direction in FIG. Then, the switch 34 is turned on and a detection signal is output to the arithmetic unit 36. Therefore, the calculation unit 36 determines that the contact 21 is in the contact state and the rotating shaft 14 is rotated, and adopts the contact-type calculation coefficient to detect the light receiving element 1.
The rotation speed of the object to be measured is calculated based on the detection pulse output from 0. In particular, in this example, since many reflection seals 32 are attached along the rotation direction of the disk 30, the number of detection pulses output from the light receiving element 10 per one rotation of the rotation shaft 14 increases, Therefore, even if the rotation speed of the object to be measured is low, the calculation unit 36 can obtain an accurate calculation result. Then, the calculation result is displayed on the display 38 of the next stage.

When used as a contact type, it is desirable to shield the light passage opening 2a of the case 2 with a shield plate (not shown).

As described above, when the handheld tachometer 1 having the configuration shown in FIGS. 1 and 2 is used in the contact type, an accurate calculation result can be obtained even when the rotation speed of the object to be measured is low. Further, since the non-contact type rotation detection system 4 and the contact type rotation detection system 6 are parallel to each other, even when the contact type and the non-contact type are selectively used, it is not necessary to change the orientation of the case 2 as a whole. , When using both types separately, without changing the arithmetic processing by operating a manual switch,
Since the micro switch 34 acts as a means for detecting the presence or absence of rotation of the rotary shaft 14 and automatically switches the calculation coefficient of the rotation speed, the rotation speed of the object to be measured can be measured very easily.

In the above embodiment, the micro switch 34 is provided as the contact type detection means, but instead of this, a pressure sensor may be provided.

As shown in FIG. 3, a rotation sensor 40 including a photocoupler is provided as the contact type detection means, and the speed calculation coefficient of the calculation unit is changed according to the presence / absence of the detection output of the rotation sensor 40. You can also

Further, as the contact type detection means, as shown in FIG. 4, the light receiving element 4 is separately provided at a position where the light from the light emitting element 8 constituting the light emitting and receiving section 3 is reflected by the reflection seal 32.
2 is provided, a detection circuit 44 for detecting the presence or absence of a light receiving signal from the light receiving element 42 is provided, and when the light receiving element 42 intermittently outputs the light receiving signal as the light reflection chopper 25 rotates, The calculation unit 36 may be configured to adopt a non-contact calculation coefficient.

In FIG. 4, the light reflected by the reflective seal is received by the light receiving element 42. However, as shown in FIGS. 5 and 6, the disc 30 constituting the light reflection chopper 25 is rotated in the rotational direction. A slit 46 is sequentially formed along the slit 46, a light receiving element 42 is provided at a position facing the slit 46 of the light emitting element 8, and a detection circuit 44 for detecting the presence or absence of a light receiving signal from the light receiving element 42 is provided. It can also be configured.

[0035]

The handheld tachometer according to the present invention, when used in a contact type, can obtain an accurate calculation result even when the rotational speed of the object to be measured is low. In addition, since the non-contact rotation detection system and the contact rotation detection system are parallel, it is not necessary to change the orientation of the entire case much when using the contact type and the non-contact type separately. When differently using, the switching is automatically performed without operating the manual switch or the like and changing the arithmetic processing, and therefore the rotation speed of the object to be measured can be measured very easily.

[Brief description of drawings]

FIG. 1 is an overall configuration diagram of a handheld tachometer according to an embodiment of the present invention.

FIG. 2 is a front view of a light reflection chopper portion of the tachometer of FIG.

FIG. 3 is a configuration diagram showing a modified example of the handheld tachometer of the present invention.

FIG. 4 is a configuration diagram showing another modification of the handheld tachometer of the present invention.

FIG. 5 is a configuration diagram showing still another modification of the handheld tachometer of the present invention.

6 is a front view of a light reflection chopper portion of the tachometer of FIG.

[Explanation of Codes] 1 ... Handheld tachometer, 2 ... Case, 2a ... Light passage opening, 3 ... Emitter / receiver, 4 ... Non-contact type rotation detection system, 6 ...
Contact-type rotation detection system, 12 ... Optical means (lens), 14 ... Rotation shaft, 21 ... Contact, 25 ... Light reflection chopper, 32 ... Light reflector (reflection seal), 34 ... Contact detection means (micro switch) , 36 ... Calculation unit, 38 ... Display, x ... Optical axis.

Claims (1)

[Claims] 1. A light emitting / receiving unit, a non-contact type rotation detection system, and a contact type rotation detection system are provided in a case, and the non-contact type rotation detection system irradiates an object with light from the light emitting / receiving unit. In addition, it has optical means for guiding the reflected light from the object to be measured to the light projecting / receiving section again, and the case is formed with a light passage opening at a position intersecting with the optical axis of the optical means, The contact type rotation detection system has a rotary shaft arranged substantially parallel to the optical axis of the optical means, one end side of the rotary shaft is projected to the outside of the case, and the projected portion contacts the object to be measured. Is attached, and a light reflection chopper for intermittently reflecting the light from the light emitting / receiving unit as the rotation shaft rotates is fixed to the other end side of the rotation shaft. , While a number of light reflectors are attached along the direction of rotation, The contact type detection means for detecting the presence / absence of rotation of the rotary shaft, and the operation coefficient of the rotational speed of the object to be measured are changed according to the presence / absence of rotation detection by the contact type detection means and output from the light emitting / receiving part. A handheld tachometer, comprising: a calculation unit that calculates the rotation speed of the object to be measured based on the detected pulse, and a display that displays the calculation result of this calculation unit.