JP2710886B2 - Drum rotation sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

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

[0002]

2. Description of the Related Art In some cases, such as when performing an installation work at a high place with a crane, it is sometimes impossible to visually check the state of the suspended load and the installation surface. In such a case, a drum rotation sensing device that detects the rotation speed of the drum, particularly a low speed, drives an actuator built in the grip portion of the operation lever according to the detected speed, and transmits it to the operator as a tactile sensation of a finger. Known (for example, Japanese Utility Model Application Laid-Open No. 61-123)
No. 972).

In this drum rotation sensing device, the rotation speed of the winding drum of the crane is detected as a pulse signal by a proximity switch, and when the solenoid incorporated in the grip portion is driven in accordance with the cycle of the pulse signal, the operation of the solenoid is activated. The child reciprocates and vibrates as if to tap the operator's finger, and the operator senses the rotation speed of the drum according to the oscillation period.

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 vibrations corresponding to the rotation speed to the operator's fingers. is there.
However, when the drive current of the solenoid is increased, the frequency of the pulse signal from the proximity switch is increased when the rotation speed of the drum is high, so that the solenoid is driven at a high frequency and the average drive current is increased. As a result, the calorific value of the solenoid increases and exceeds the allowable operating temperature.

Therefore, in the drum rotation sensing device, when the rotation speed of the drum is high, the solenoid is driven in accordance with the detected speed only when the rotation speed of the drum is low without driving the solenoid in order to avoid a rise in the temperature of the solenoid. Like that.

[0006]

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

An object of the present invention is to provide a drum rotation sensing device that generates a sufficient vibration in a low speed range by using a small capacity solenoid and suppresses a rise in the temperature of the solenoid in a high speed range.

[0008]

The present invention will be described with reference to FIG. 1 which is a diagram corresponding to claims. The present invention provides a rotational speed detecting means 100 for detecting the rotational speed of a winding drum and outputting a pulse signal. And a driving means 101 for driving an actuator in accordance with an output pulse signal of the rotation speed detecting means 100. A pulse signal generating means 102 for generating a pulse signal of a predetermined time width every time a pulse signal is output from the rotation speed detecting means 100, and a time for detecting a time interval of the pulse signal output from the rotation speed detecting means 100 An interval detecting means 103; a duty ratio setting means 104 for setting a duty ratio in accordance with the time interval detected by the time interval detecting means 103;
2 is a pulse train signal generating means 1 for generating a pulse train signal of a predetermined frequency whose duty ratio has been set by the duty ratio setting means 104 while the pulse signal is being generated.
The driving means 101 achieves the above object by driving the actuator in accordance with the pulse train signal of the pulse train signal generating means 105.

[0009]

The pulse signal generating means generates a pulse signal of a predetermined time width every time a pulse signal is output from the rotational speed detecting means, and a duty ratio setting means.
Sets the duty ratio according to 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 generates a pulse signal from the pulse signal generating means 102. During this period, the duty ratio setting means 104 generates a pulse train signal of a predetermined frequency whose duty ratio has been set, and the driving means 101 drives the actuator according to the pulse train signal.

[0010]

FIG. 2 is a block diagram showing the configuration of one embodiment. In FIG. 1, 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, which measures a time interval t1 of the pulse signal Sig1 by a software timer T1, and counts a time t1.
Sig2 for setting the duty ratio according to
And a pulse signal Sig3 having a predetermined time width t2 is generated each 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. The pulse train signal has a preset frequency and a duty ratio set according to the signal Sig2 while the pulse signal Sig3 is supplied. Sig4 is output. Note that the pulse signal Sig
Reference numeral 3 denotes an activation signal for activating the pulse train signal generation circuit 3. Reference numeral 4 denotes a driver, which is a pulse train signal Sig.
In accordance with 4, the solenoid 5 built in the operation lever is driven. Reference numeral 6 denotes a well-known flywheel diode connected to the solenoid 5 in parallel.

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 starts counting the clock signal again. Here, register R
The setting value of 2 determines the period t3 of the sawtooth wave of the counter C1, as shown in FIG. 3A, and thereby determines the frequency f (= 1 / t3) of the pulse train signal. Further, a signal S for setting a duty ratio is provided 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
Is set to be equal to the set value of the register R2.

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

Next, the operation of the controller 2 will be described.
FIGS. 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 device. The operation of the apparatus will be described with reference to these drawings. The controller 2 is shown in FIG.
As shown in FIG. 4A, when the pulse signal Sig1 is supplied from the proximity switch 1 with the rotation of the drum, FIG.
The execution of the pulse interrupt program shown in (1) is started. In step S1, the current value of the timer T1 for measuring the time interval of the pulse signal Sig1 is stored in the memory M1. This control program is started each time a pulse signal is generated from the proximity switch 1. Therefore, the time stored in the memory M1 in step S1 is equal to the time from the last pulse signal generation to the current pulse signal generation. This is a time interval t1. In the low-speed range, the count value of the timer T1 is limited to the maximum value MAX as shown in FIG.

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

On the other hand, the controller 2 measures a built-in clock signal and executes a timer interrupt program shown in FIG. 5 at regular intervals. In step S11, the timer T
It is determined whether the current value of 1 is the maximum value. If the current value is the maximum value, the process proceeds to step S13; otherwise, the timer T1 is incremented in step S12. In step S13,
It is determined whether or not the timer T2 is 0.
Proceed to step S16, otherwise proceed to step S14. In step S16, since the drive time t2 of the solenoid 5 has elapsed, the duty ratio is set to 0, and a setting signal Sig2 having a 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. In 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), a 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 time interval t1 of the pulse generated by the proximity switch 1 is long, and small when the time interval t1 is short. That is, when the rotation speed of the drum is low, the duty ratio is large, and the solenoid 5 is driven with a large current.
Conversely, 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 a pulse train signal Sig4 output from the pulse train signal generation circuit 3. As described above, the pulse train signal Sig4 has a predetermined frequency f (= 1
/ T3) and the duty ratio, and are supplied to the driver 4 only during the drive time t2 set by the timer T2. In the low speed range, the duty ratio becomes 1,
During the drive time t2, the Hi-level signal Sig4 is always output. On the other hand, in the middle speed range, a pulse train signal Sig4 having a frequency f according 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 that 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 having a small duty ratio is generated. Output continuously.

FIG. 6F 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 middle speed range, the pulse train signal Si
Since the solenoid 5 is turned on and off in accordance with g4, the peak value of the drive current becomes lower. Furthermore, as the rotation speed of the drum increases, the duty ratio decreases as described above, and thus the peak value of the drive current decreases. In the high-speed range, the solenoid 5 is continuously turned on and off. However, 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.

As described above, the rotation speed of the winding drum is detected by the proximity switch 1, the pulse time interval t1 from the proximity switch 1 is measured by the controller 2, and the duty ratio setting signal Sig2 corresponding to the time interval t1 is measured. Is output to the pulse train signal generation circuit 3 and the activation signal Sig3 of the pulse train signal generation circuit 3 for a predetermined time t2 is output every time the proximity switch 1 generates a pulse. Then, the pulse train generation circuit 3 generates the pulse train signal Si according to the set duty ratio, the predetermined frequency f and the start time t2.
g4, and the driver 4 generates the pulse train signal Si
The solenoid 5 was driven according to g4. As a result, sufficient vibration can be generated at a low speed using a small solenoid, and the rotational speed of the drum is transmitted to the operator as tactile sensation of the fingers. Further, at high speed, heat generation of the solenoid can be suppressed low. Further, in the conventional drum rotation sensing device, the solenoid was not driven in order to suppress heat generation in the high-speed range, so that the drum rotation could not be detected in the high-speed range. Micro-vibration corresponding to the rotation speed is obtained, and the rotation state of the winding drum can be transmitted to the operator from a low speed to a high speed. Furthermore, since a sufficient vibration can be obtained even with a small actuator, it can be easily incorporated into the grip portion of the operation lever. In addition, since the heat generated by the actuator can be suppressed to a low level, the actuator section can be made to have a sealed structure, and the reliability in an operating environment where there are many water drops and dust can be improved.

In the above embodiment, the pulse train signal generating circuit 3
Is used to generate the pulse train signal, but the controller 2 including a microcomputer may generate the pulse train signal by software. In the above embodiment, the controller 2 is constituted by a microcomputer.
It may be configured by hardware using a timer and a memory.

In the above embodiment, a solenoid is used as an actuator for generating vibration. However, an actuator for driving a motor to generate vibration in accordance with a driving speed may be used.

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

[0024]

As described above, according to the present invention, a pulse signal of a predetermined time width is generated by the pulse signal generation means every time a pulse signal is output from the rotation speed detection means of the winding drum. The detecting means detects the time interval of the generated pulse signal of the rotation speed detecting means, and the duty ratio setting means sets the duty ratio according to the 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 of the set duty ratio is generated, and the driving means drives the actuator according to the pulse train signal. did. As a result, sufficient vibration can be obtained in a low-speed range even with a small actuator, 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 has not been detected by the conventional device, a fine vibration corresponding to the rotation speed of the drum can be obtained.
The rotation state of the winding drum can be transmitted to the operator from a low speed to a high speed. Furthermore, sufficient vibration can be obtained even with a small actuator, so that it can be easily incorporated into the grip of the operation lever. In addition, since the heat generated by the actuator can be suppressed to a low level, the actuator must have a sealed structure. And reliability in a use environment where there are many water drops and dust can be improved.

[Brief description of the drawings]

FIG. 1 is a diagram corresponding to claims.

FIG. 2 is a block diagram showing a configuration of one embodiment.

FIG. 3 illustrates an operation of a pulse train signal generation circuit.

FIG. 4 is a flowchart showing a pulse interrupt program executed by a 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 a signal waveform of each part of the device.

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

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Proximity switch 2 Controller 3 Pulse train signal generation circuit 4 Driver 5 Solenoid 100 Rotation 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)

(57) [Claims] 1. A drum comprising: a rotation speed detection means for detecting a rotation speed of a winding drum and outputting a pulse signal; and a drive means for driving an actuator in accordance with the output pulse signal of the rotation speed detection means. In the rotation sensing device, each time a pulse signal is output from the rotation speed detection unit, a pulse signal generation unit that generates a pulse signal having a predetermined time width, and a time interval between the pulse signals output from the rotation speed detection unit is detected. A time interval detecting means, a duty ratio setting means for setting a duty ratio according to the time interval detected by the time interval detecting means, and the pulse signal generating means while the pulse signal is being generated. A pulse train signal generating means for generating a pulse train signal of a predetermined frequency whose duty ratio has been 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.