JPH0712950U - V belt slack alarm device - Google Patents

Abstract

(57) [Abstract] [Purpose] To provide a circuit that automatically detects the looseness of a V-belt of a vehicle and issues an alarm. A comparator 5a compares outputs of an engine speed sensor 1 and a pickup of an alternator 2 and activates an alarm device 6 when a looseness is detected.

Description

[Detailed description of the device]

[0001]

[Industrial applications]

 The present invention relates to a V-belt slack alarm device for connecting an engine to another load in an engine room of an automobile.

[0002]

[Prior art and its problems]

 In recent automobiles, the alternator is becoming larger due to the increase in the amount of electricity generated by idling, along with the increase in electronic control and accessories. For this reason, it is difficult to follow the rotational fluctuation due to the increase of the inertial mass of the alternator and the increase of the driving torque. As a result, as the load on the V-belt connecting the engine to the alternator, fan, etc. increases, the V-belt extension becomes more problematic than in the past. When the V-belt is stretched or the like, the looseness causes slippage, and especially when the engine speed fluctuates greatly during idling, the belt swings greatly and the slip becomes serious. The conventional detection of looseness of the V-belt is found in the regular inspection of the vehicle, and the driver notices it due to the increase in the slip noise. Under these circumstances, however, it is necessary to wait until the regular inspection. Since the exact degree of loosening cannot be grasped, there are some problems such as early wear.

An object of the present invention is to provide an alarm device which automatically detects looseness of a V-belt, prevents early wear, and issues an alarm.

[0004]

[Means for Solving the Problems]

 The present invention, which achieves the above-mentioned object, includes a comparison circuit that compares signals based on both the engine speed sensor and the alternator speed, and a timer that outputs only when the same comparison output from this comparison circuit continues for a certain period of time. , And an alarm that can be activated by this timer output.

[0005]

[Action]

 The occurrence of slippage due to the looseness of the V-belt causes a difference in rotation speed between the engine rotation speed and the alternator rotation speed, and an alarm (alarm) based on this rotation speed difference causes the difference in rotation speed and the degree of slippage. Can be detected and an alarm can be issued.

[0006]

【Example】

 An embodiment of the present invention will now be described with reference to FIGS. FIG. 1 is a block diagram showing the principle of the present invention. In FIG. 1, an engine speed sensor 1 outputs a frequency signal corresponding to the engine speed. In this case, the engine speed sensor 1 may be a tachometer or a sensor for an electronic governor. Further, the rotation of the alternator 2 can be detected by using the P terminal generated pulse by the rotation speed pickup. In many cases, these sensors 1 and pickups are already mounted, but even if they are not installed, a mounting seat is provided for new mounting, and those skilled in the art can easily mount them.

F / V converters 3 and 4 are provided in the subsequent stages of the engine speed sensor 1 and the pickup, respectively. The F / V converters 3 and 4 respectively convert into a voltage according to the frequency of the sensor 1 and a voltage according to the number of pulses from the pickup, and a voltage output appears. In this case, since the voltage value based on the engine speed sensor 1 and the voltage value based on the alternator 2 are not related to each other, for example, the output of the F / V converter 4 is based on the output of the F / V converter 3. It is necessary to make corresponding corrections. That is, for example, it is necessary to correct the F / V converter 4 so that the output voltages of the F / V converters 3 and 4 have the same value in the absence of slip.

The output terminals of the F / V converters 3 and 4 reach the relay 5 with a built-in comparison circuit, and are connected to the two inputs of the comparator 5a therein. The comparator 5a compares and determines which of the two inputs to be compared is larger. For example, when slippage occurs and the voltage value of the alternator 2 becomes lower than the voltage value of the engine rotation sensor 1, (+ ) Output is generated. In this case, it is necessary to set how much the output of the comparator 5a is obtained depending on the degree of slip. Generally, the use limit of the V-belt is that the slip of 4% with respect to the engine speed occurs in the low engine speed range. For example, the use limit is that the slip of 40 rotations occurs at 1000 revolutions. Has become. As an alarm due to increased slip, for example, if slip occurs due to hardware and software, it does not pose a problem and is within the normal range of 1%, that is, slip of about 10 revolutions per 1000 revolutions. Taking into account the temporary fluctuations in rotation and the increase in slip as a reference, there is a margin of 1% and the output at about 2% is considered. Therefore, when drawing is performed at this 2%, the output of the comparator 5a is changed from (-) to (+), for example, with the voltage output difference of the F / V converters 3 and 4 corresponding to this 2% as the boundary. You can do it like this. For this reason, it is necessary to adjust the variable resistors 5b and 5c so as to change the output of the comparator 5a with an output difference of 2%. Thus, when the rotation of the alternator 2 causes a slip of 2% or more with respect to the engine rotation of the engine rotation speed sensor 1, the output of the comparator 5a is compared by the voltage comparison at that time. The output changes.

In the comparison circuit built-in relay 5, a timer 5d is arranged after the comparator 5a. The timer 5d measures, for example, the continuation of the above (+) output for a certain period of time, and turns on the transistor 5e in the next stage only when the (+) output continues for 10 seconds or 5 seconds, for example. It is a thing. This is to prevent the transistor 5e from turning on due to a change in the output of the comparator 5a due to a temporary or instantaneous increase in slip, so that the transistor 5e does not frequently turn on / off due to fluctuations in rotation or the like. This is because The time length of the timer 5d may be a time that does not respond to an instantaneous slip, so it is empirically considered that a few seconds are sufficient.

When the transistor 5e in the output stage of the comparison circuit built-in relay 5 is turned on, the alarm device 6 such as a buzzer or a lamp is turned on. The power supply of the alarm device 6 is connected via the ACC terminal of the key switch 8 connected to the battery 7 in this example.

FIG. 2 shows the relay 5 with built-in comparison circuit and the alarm device 6 of FIG. 1 in multiple stages for easy understanding. In FIG. 2, the same parts as those in FIG. 1 are designated by the same reference numerals, but in the circuit shown in FIG.₁, E₀Is E₁= E₀Variable resistor R so that₁Is adjusted. The output of the F / V converter 3 has four comparators 5a.₁~ 5a_FourIs input to the (-) input terminal of the comparator 5a₁Resistor R₁Through the comparator 5a₂~ 5a_FourThe voltage divided in order is applied to. Therefore, the comparator 5a₁~ 5a_FourA voltage that gradually decreases due to the resistance voltage drop is applied to the (-) input of. On the other hand, the comparator 5a₁~ 5 a_FourThe other (+) input terminal of the₀Is added. Each comparator 5a₁~ 5a_FourLED on₁~ LED_FourIs connected according to₁> E₀In case of LED₁Lights up and E₂> E₀In case of LED₁ , LED₂Lights up and E₃> E₀In case of LED₁, LED₂, LED₃Lights up and E_Four> E₀LED when₁, LED₂, LED₃, LED_FourLights up. In other words, the more LEDs are turned on, the more slippage becomes. Here, the voltage V₁Corresponding to the above-mentioned slip of 1%, for example, V₂2%, V ₃ 3% and V_FourIs set to correspond to 4% of the usage limit.

[0012]

[Effect of device]

 As described above, according to the present invention, since the V-belt slip is automatically detected and an alarm such as a display is issued, the V-belt slip can be automatically controlled and the V-belt is prevented from being worn or cut. You can

[Brief description of drawings]

FIG. 1 is a block diagram showing the principle of the present invention.

FIG. 2 is a block diagram showing a specific example.

[Explanation of symbols]

1 engine speed sensor 2 alternator 3,4 F / V converter 5b, 5c, R ₁ variable resistor 5a, 5 _{1 to} 5 ₄ comparator 5d timer 5e transistor 6 alarm device

Claims (1)

[Scope of utility model registration request] 1. A comparison circuit for comparing signals based on both an engine speed sensor and an alternator speed, a timer for outputting only when the same comparison output from this comparison circuit continues for a fixed time, and a timer output for this timer output. A V-belt slack warning device having an alarm that can be activated.