JPH05105389A - Drum rotation sensor - Google Patents

Abstract

PURPOSE:To enable a state of rotation to be transmitted from its low speed to high speed by generating a pulse train signal of a specified frequency whose duty ratio is set by a duty ratio setting means, by a pulse train signal generating means during a period in which it generates pulse signal so as to drive an actuator by a driving means. CONSTITUTION:When a pulse signal (Sig1) is supplied from a proximity switch 1, a controller 2 clears a timer T1 to measure the time interval from this time till next time, and sets the driving time of a solenoid 5 in a timer T2. Next, a duty ratio is set in response to the time interval of the pulse of the proximity switch 1, and a set signal (Sig2) in response to the duty ratio is output to a pulse train signal generating circuit 3. A pulse train signal (Sig4) output from the pulse train signal generating circuit 3 is determined by specified frequency and the duty ratio, and supplied to a driver 4 to the extent of the driving time of the timer T2. Driving current from the driver 4 to the solenoid 5 is a driving current whose peak value is large in a low speed zone and generates sufficiently large vibration.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a drum rotation detecting device for detecting the rotation speed of a winding drum of a crane or the like and transmitting it to an operator.

[0002]

2. Description of the Related Art When a crane is used for installation work at a high place, it may not be possible to visually check the suspended load and the installation surface. In such a case, a drum rotation sensing device that detects the rotation speed of the drum, especially a low speed, drives the actuator built in the grip part of the operating lever according to the detected speed, and transmits it to the operator as a tactile sensation of the finger. It is known (for example, the actual exploitation Sho 61-123
972).

In this drum rotation detecting device, the proximity switch detects the rotation speed of the winding drum of the crane as a pulse signal, and when the solenoid incorporated in the grip portion is driven in accordance with the cycle of the pulse signal, the solenoid operates. The child reciprocates and vibrates like hitting the operator's finger, and the operator senses the rotation speed of the drum by the vibration cycle.

By the way, when the rotation speed of the drum is low, it is necessary to increase the attraction force of the solenoid, that is, to increase the drive current to some extent, in order to reliably apply the vibration corresponding to the rotation speed to the fingers of the operator. is there.
However, if the drive current of the solenoid is increased, the frequency of the pulse signal from the proximity switch increases when the rotation speed of the drum is high, so the solenoid is driven at a high frequency and the average drive current increases. As a result, the amount of heat generated by the solenoid increases, exceeding the allowable operating temperature.

Therefore, in the drum rotation detecting device, in order to avoid the temperature rise of the solenoid when the rotation speed of the drum is high, the solenoid is not driven, and the solenoid is driven according to the detected speed only when the rotation speed of the drum is low. I am trying.

[0006]

However, in such a conventional drum rotation sensing device, sufficient vibration is generated at the maximum value of the rotation speed in the low speed range which is desired to be transmitted to the operator's finger as a tactile sensation, and the solenoid Although it is necessary to determine the capacity of the solenoid so that the temperature rise is within the allowable value, there is a problem that a solenoid having a sufficient capacity that satisfies these conditions has a large size and cannot be housed in the grip of the operating lever.

An object of the present invention is to provide a drum rotation sensing device which uses a small capacity solenoid to generate sufficient vibration in a low speed range and keeps the temperature rise of the solenoid low in a high speed range.

[0008]

The present invention will be described with reference to FIG. 1, which is a claim correspondence diagram, and the present invention detects the rotational speed of a winding drum and outputs a pulse signal to the rotational speed detecting means 100. And a drive means 101 for driving an actuator in accordance with the output pulse signal of the rotation speed detecting means 100. Then, each time the rotation speed detecting means 100 outputs a pulse signal, a pulse signal generating means 102 for generating a pulse signal having a predetermined time width, and a time for detecting a time interval between the pulse signals output from the rotation speed detecting means 100. The interval detecting means 103, the duty ratio setting means 104 for setting the duty ratio according to the time interval detected by the time interval detecting means 103, and the pulse signal generating means 10.
Pulse train signal generating means 1 for generating a pulse train signal of a predetermined frequency whose duty ratio is set by the duty ratio setting means 104 while the pulse signal is being generated from 2
The driving means 101 achieves the above-mentioned object by driving the actuator according to the pulse train signal of the pulse train signal generating means 105.

[0009]

The pulse signal generating means 102 generates a pulse signal having a predetermined time width each time the rotation speed detecting means 100 outputs the pulse signal, and the duty ratio setting means 104.
Sets the duty ratio in accordance with the time interval of the output pulse signal of the rotation speed detecting means 100 detected by the time interval detecting means 103, and the pulse train signal generating means 105 causes the pulse signal generating means 102 to generate a pulse signal. During this period, the duty ratio setting means 104 generates a pulse train signal having a predetermined frequency for which the duty ratio is set, and the driving means 101 drives the actuator according to the pulse train signal.

[0010]

FIG. 2 is a block diagram showing the structure of an embodiment. In the figure, reference numeral 1 denotes a proximity switch, which detects the rotation speed of the winding drum and generates a pulse signal Sig1 having a cycle corresponding to the rotation speed. Reference numeral 2 denotes a controller composed of a microcomputer and peripheral components such as a memory M1. The software timer T1 measures the time interval t1 of the pulse signal Sig1 to measure the time t1.
Signal Sig2 for setting the duty ratio according to
And a pulse signal Sig3 having a predetermined time width t2 is generated every time the pulse signal Sig1 is input by the software timer T2.

Reference numeral 3 denotes a pulse train signal generating circuit such as a universal pulse processor, which has a preset frequency while the pulse signal Sig3 is supplied and has a duty ratio set in accordance with the signal Sig2. Output Sig4. The pulse signal Sig
Reference numeral 3 is a start signal for starting the pulse train signal generation circuit 3. 4 is a driver, which is a pulse train signal Sig
The solenoid 5 built in the operation lever is driven according to 4. In addition, 6 is a well-known flywheel diode connected in parallel to the solenoid 5.

First, the operation of the pulse train signal generation circuit 3 will be described. When the activation signal Sig3 is supplied from the controller 2, the counter C1 starts counting the clock signal of the clock CLK. As shown in FIG. 3A, when the count value of the counter C1 reaches a value preset in the register R2, the counter C1 is reset and the counting of the clock signal is started again. Where register R
The set value of 2 determines the cycle t3 of the sawtooth wave of the counter C1 as shown in FIG. 3 (a), and thereby the frequency f (= 1 / t3) of the pulse train signal is determined. In addition, the signal S for setting the duty ratio from the controller 2
ig2 is supplied and stored in the register R1. The duty ratio setting signal Sig2 has a duty ratio of 1
At this time, it is set to be equal to the set value of the register R2.

As shown in FIG. 3A, the comparator CMP includes a count value of the counter C1 (indicated by a solid line in the figure) and a duty ratio setting signal Sig2 stored in the register R1 (indicated by a broken line in the figure). 3), the pulse train signal Sig4 of Hi level is output when the latter is larger than the former. That is, the pulse train signal Sig4 has the preset frequency f.
It is determined by (= 1 / t3) and the duty ratio according to the duty ratio setting signal Sig2. When the duty ratio is 1, the Hi level is output, and when the duty ratio is 0, the Lo level is output.

Next, the operation of the controller 2 will be described.
4 and 5 are flowcharts showing a control program executed by the controller 2, and FIG. 6 is a time chart showing signal waveforms of various parts of the apparatus. The operation of the apparatus will be described with reference to these figures. The controller 2 is shown in FIG.
As shown in FIG. 4A, when the pulse signal Sig1 is supplied from the proximity switch 1 as the drum rotates, as shown in FIG.
Start execution of the pulse interrupt program shown in. In step S1, the current value of the timer T1 that measures the time interval of the pulse signal Sig1 is stored in the memory M1. Since this control program is activated each time a pulse signal is generated from the proximity switch 1, the time stored in the memory M1 in step S1 is the pulse from the last pulse signal generation to the current pulse signal generation. The time interval is t1. In the low speed range, the time value of the timer T1 is limited to the maximum value MAX as shown in FIG. 6 (b).

In step S2, the timer T1 is cleared in order to measure the time interval t1 from this time to the next time, and in the following step S3, a predetermined value OST is set in the timer T2 as shown in FIG. 6 (c). This predetermined value OST determines the drive time t2 of the solenoid 5 that is driven each time a pulse signal is generated by the proximity switch 1 as the drum rotates. When the above processing is completed, the controller 2 returns to the normal main control program.

On the other hand, the controller 2 measures the internal clock signal and executes the timer interrupt program shown in FIG. 5 at regular intervals. In step S11, the timer T
It is determined whether or not the current value of 1 is the maximum value, and if it is the maximum value, the process proceeds to step S13, and if not, the timer T1 is incremented in step S12. In step S13,
It is determined whether or not the timer T2 is 0, and if it is 0, step S
16. If not, proceed to step S14. In step S16, since the driving time t2 of the solenoid 5 has elapsed, the duty ratio is set to 0 and the setting signal Sig2 with the duty ratio of 0 is output to the pulse train signal generation circuit 3.

On the other hand, in step S14, the timer T2 is decremented, and in the following step S15, the duty ratio is set as shown in FIG. 7 according to the pulse time interval t1 of the proximity switch 1 stored in the memory M1. 6
As shown in (d), the setting signal Sig2 corresponding to the duty ratio is output to the pulse train signal generation circuit 3. This duty ratio is large when the generated pulse time interval t1 of the proximity switch 1 is long, and is small when the time interval t1 is short. That is, when the rotation speed of the drum is slow, the duty ratio is large and the solenoid 5 is driven with a large current,
On the contrary, when the rotation speed is high, the duty ratio is small and the drive current of the solenoid 5 is limited to suppress heat generation. As described above, the duty ratio setting signal Si
g2 is equal to the set value of the register R2 when the duty ratio is 1.

FIG. 6E shows the pulse train signal Sig4 output from the pulse train signal generation circuit 3. The pulse train signal Sig4 has a predetermined frequency f (= 1) as described above.
/ T3) and the duty ratio, and is supplied to the driver 4 only during the driving time t2 set by the timer T2. In the low speed range, the duty ratio becomes 1,
During the driving time t2, the Hi-level signal Sig4 is constantly output. On the other hand, in the medium speed range, the pulse train signal Sig4 having the frequency f corresponding to the duty ratio is output. Further, in the high speed range, as shown in FIG. 6C, the output of the timer T2 does not become 0, so the start signal Sig3 of the pulse train signal generation circuit 3 is always in the input state, and the pulse train signal Sig4 of the frequency f with a small duty ratio is generated. It is output continuously.

FIG. 6 (f) shows the drive current of the solenoid 5 output from the driver 4 according to the pulse train signal Sig4. In the low speed range, the solenoid 5 is driven by a drive current having a large peak value, and a sufficiently large vibration is generated. However, in this low speed range, since the driving cycle is long, the average value of the driving current is small, and therefore the amount of heat generated by the solenoid 5 is small. In the medium speed range, the pulse train signal Si during one driving time
Since the solenoid 5 is turned on / off according to g4, the peak value of the drive current becomes low. Furthermore, the higher the rotational speed of the drum, the smaller the duty ratio as described above, and the lower the peak value of the drive current. Further, in the high speed range, the solenoid 5 is continuously turned on and off, but since the duty ratio of the pulse train signal Sig4 is small, the peak value of the drive current becomes low and the solenoid 5
Fever is small.

In this way, the proximity switch 1 detects the rotational speed of the winding drum, the controller 2 measures the pulse time interval t1 from the proximity switch 1, and the duty ratio setting signal Sig2 corresponding to this time interval t1. Is output to the pulse train signal generation circuit 3, and a start signal Sig3 for the pulse train signal generation circuit 3 for a predetermined time t2 is output every time the proximity switch 1 generates a pulse. Then, in the pulse train generation circuit 3, the pulse train signal Si is set according to the set duty ratio, the predetermined frequency f and the starting time t2.
g4 is generated, and this pulse train signal Si is generated by the driver 4.
The solenoid 5 is driven according to g4. As a result, a small solenoid can be used to generate sufficient vibration at low speeds, and the rotational speed of the drum is reliably transmitted to the operator as a tactile sensation of the fingers. Further, at high speed, heat generation of the solenoid can be suppressed to a low level. Further, in the conventional drum rotation sensing device, the solenoid is not driven in order to suppress heat generation in the high speed range, so the drum rotation in the high speed range cannot be detected. A slight vibration according to the rotation speed can be obtained, and the rotation state of the winding drum can be transmitted to the operator from low speed to high speed. Further, even a small actuator can obtain sufficient vibration, so that it can be easily incorporated in the grip portion of the operation lever. Further, since the heat generation of the actuator can be suppressed to a low level, the actuator part can have a hermetically sealed structure, and the reliability with respect to the usage environment where there are many water drops and dust can be improved.

In the above embodiment, the pulse train signal generation circuit 3
Although the pulse train signal is generated using, the pulse train signal may be generated by software with the controller 2 including a microcomputer. Further, in the above embodiment, the controller 2 is composed of a microcomputer,
It may be configured by hardware using a timer and a memory.

In the above embodiment, the solenoid is used as the actuator for generating the vibration, but an actuator or the like for driving the motor to generate the vibration according to the driving speed may be used.

In the configuration of the above embodiment, the proximity switch 1 is the rotational speed detecting means, the controller 2 is the pulse signal generating means, the time interval detecting means and the duty ratio setting means, and the pulse train signal generating circuit 3 is the pulse train signal generating means. The driver 4 constitutes a driving means.

[0024]

As described above, according to the present invention, a pulse signal having a predetermined time width is generated every time the pulse signal is output from the rotation speed detecting means of the winding drum by the pulse signal generating means, and the time interval is increased. The detection unit detects the time interval of the pulse signal generated by the rotation speed detection unit, and the duty ratio setting unit sets the duty ratio in accordance with this time interval. Then, while the pulse signal is being generated from the pulse signal generating means by the pulse train signal generating means, a pulse train signal having a predetermined frequency with a set duty ratio is generated, and the driving means drives the actuator according to the pulse train signal. did. As a result, even a small actuator can obtain sufficient vibration in a low speed range, and a sufficient tactile sensation with a finger can be transmitted to the operator according to the rotation speed of the drum.
Also, in the high speed range, the heat generation of the actuator can be suppressed to a low level, and even in the high speed range, which was not detected by the conventional device, a slight vibration according to the rotation speed of the drum can be obtained.
The rotation state of the winding drum can be transmitted to the operator from low speed to high speed. In addition, since a small actuator can obtain sufficient vibration, it can be easily incorporated into the grip part of the operating lever and the heat generation of the actuator can be kept low. Therefore, it is possible to improve reliability in an environment where there are many water droplets and dust.

[Brief description of drawings]

FIG. 1 is a diagram for responding to a complaint.

FIG. 2 is a block diagram showing the configuration of an embodiment.

FIG. 3 is a diagram explaining an operation of a pulse train signal generation circuit.

FIG. 4 is a flowchart showing a pulse interrupt program executed by the microcomputer of the controller.

FIG. 5 is a flowchart showing a timer interrupt program executed by the microcomputer of the controller.

FIG. 6 is a time chart showing signal waveforms of various parts of the apparatus.

FIG. 7 is a diagram showing a relationship between a pulse time interval and a duty ratio.

[Explanation of symbols]

 1 Proximity Switch 2 Controller 3 Pulse Train Signal Generation Circuit 4 Driver 5 Solenoid 100 Rotational Speed Detection Means 101 Driving Means 102 Pulse Signal Generation Means 103 Time Interval Detection Means 104 Duty Ratio Setting Means 105 Pulse Train Signal Generation Means

Claims (1)

[Claims] 1. A drum comprising: a rotation speed detecting means for detecting a rotation speed of a winding drum and outputting a pulse signal; and a driving means for driving an actuator according to the output pulse signal of the rotation speed detecting means. In the rotation sensing device, a pulse signal generating means for generating a pulse signal having a predetermined time width each time a pulse signal is output from the rotation speed detecting means, and a time interval between the pulse signals output from the rotation speed detecting means is detected. Time interval detection means, a duty ratio setting means for setting a duty ratio according to the time interval detected by the time interval detection means, and while the pulse signal is generated from the pulse signal generation means, A pulse train signal generator for generating a pulse train signal of a predetermined frequency whose duty ratio is set by the duty ratio setting means. With the door, said drive means, the drum rotation sensing apparatus characterized by driving the actuator in response to the pulse train signal of the pulse train signal generating means.