JPS63162940A - Belt tension abnormality detecting device for engine - Google Patents

Abstract

PURPOSE:To enable instantaneous discrimination of tension abnormality, by a method wherein information on abnormality of the number of revolutions is provided by means of a position display part and a reference display part, which are formed to a rotary plate. CONSTITUTION:Position display parts 20, disposed at intervals of a low angle and at equal intervals, and reference display parts 21, disposed at intervals of a high angle and at equal intervals, are mounted to the peripheral edge part of a rotary plate 15 connected to a driven pulley 4a connected to a drive pulley 3 through a timing belt 6a. Further, number of revolutions detectors 22b and 23b are mounted on the two display parts 20 and 21 in a manner to be positioned facing each other, and are connected to an electronic control device 24. This constitution calculates the instantaneous number of revolutions by counting a detecting signal from the position display part 20, and calculates the average number of revolutions from a period measured based on a detecting signal from the reference display part 21, and a difference between the instantaneous number of revolutions and the average number of revolutions is compared with a preset reference value. When the difference between the numbers of revolutions is wide, a signal is inputted to an abnormality display device 31.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an engine belt tension abnormality detection device that instantly notifies an abnormality when a timing belt shows signs of loosening or the like.

[Prior Art and Problems to be Solved by the Invention] Generally, in OHC type engines, a camshaft and a crankshaft are often connected via a timing belt.

When the tension of this timing belt falls below a certain value,
The rotation of the crankshaft and the rotation of the force shafts 1 to 1 are inconsistent, causing engine malfunction.

Conventionally, the tension of the timing belt has been checked using a tension gauge during periodic inspections, but it is difficult to deal with the case where an abnormality in the tension of the timing belt occurs immediately after the inspection.

To deal with this, for example, Japanese Utility Model Application Publication No. 57-32245 discloses that the number of revolutions of the crankshaft and the number of revolutions of an alternator connected to this crankshaft 1 shift via a belt are detected, and the A belt tension abnormality detection device is illustrated that issues an alarm as a belt tension abnormality when the rotational speed of the generator becomes lower than the rotational speed of the crankshaft.

However, the belt tension abnormality detection device illustrated in this prior art requires means for sensing the rotation speed of the crankshaft and means for sensing the rotation speed of the alternator, and both of these devices are required. Means for sensing the rotational speed must be installed near the crankshaft and the alternator, respectively, which complicates the electrical wiring that connects them, and furthermore increases the size of the entire device. .

[Object of the Invention] The present invention has been made in view of the above-mentioned circumstances, and is capable of providing an engine belt tension abnormality that does not require an enlarged structure, is easy to wire, and can instantly identify tension abnormalities. The purpose is to provide a detection device.

[Means for Solving the Problems] The belt tension abnormality detection device according to the present invention includes a driven pulley connected to a drive pulley connected to the crankshaft via a timing belt, and a rotor plate connected to the driven pulley. On the peripheral edge of the rotor plate, there are position display sections arranged at narrow angles and at intervals, and reference display sections arranged at equal intervals at angles wider than the positive 252 display section. is provided, and further on both the display portions of the rotor plate,
A rotation speed detection device is provided opposite to the rotation speed detection device, and this rotation speed detection device is connected to an electronic control device. At the same time, the average rotational speed is calculated from the period measured based on the detection signal of the reference display section of the rotor plate, and the difference between the calculated instantaneous rotational speed and the average rotational speed is set to a preset reference value. The device is provided with a calculation unit that compares the difference in rotation speed with the rotation speed difference, and a display drive circuit that applies a signal to the abnormality display device when the compared rotation speed difference is large.

[Embodiments of the invention] Hereinafter, the present invention will be described in detail with reference to the drawings.

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic diagram of a belt tension abnormality detection device, Fig. 2 is a vertical sectional view of a destroyer, Fig. 3 is a schematic diagram of a horizontally opposed engine, and Fig. 4 A block diagram of the belt tension abnormality detection device, FIG. 5 is a flowchart 1 of the belt tension abnormality detection device.

In FIG. 3, reference numeral 1 is a crankshaft numbered in the crank chamber of a horizontally opposed OHC engine, and cam shirts l-2a are installed on both sides of the crankshaft 71-1 in a cam chamber (not shown). .

2b are arranged facing each other. Further, a drive pulley 3 is mounted on one end of the crankshaft 1, and driven pulleys 4a, 4b are mounted on one ends of the camshafts 1-2a, 2b, respectively. Further, below the drive pulley 3 in the figure, a driven pulley 5 is arranged to drive auxiliary parts such as an oil pump (not shown).

A timing belt 6a is stretched between the drive pulley 3, the driven pulley 4a1, and the driven pulley 5.
Another timing belt 6b is stretched between
The tension of each timing bell h6a, 6b is set to a constant value by a tension pulley 7.

Note that the reference numeral 8 is an idler.

In addition, the driven pulley 4a8 is equipped with the force t.
A destripuator drive gear 9 is shaft-mounted at (t!II) of the seventh foot 2a.

On the other hand, reference numeral M10 indicates a distributator, which rotates @12 from the lower end of the housing 11 of the distributor 10.
is protruded from the rotary shaft 12, and a distributator driven gear 13 that meshes with the distributor drive gear 9 is mounted on the rotary shaft 12.

As shown in FIG. 2, the upper part of the rotation @ 12 of the distributor 10 is seeded into the housing 11,
It is supported via a bearing 14.

Roughly speaking, a rotor plate 15 and a rotor 17 isolated from the rotor brake 1-15 via a seal cover 16 are mounted on the upper part of the bearing 14 of this rotation @12.

In addition, the reference numeral 18 in FIG. 1 is an ignition coil, and 19 is an ignition coil.
is the igniter.

Further, as shown in FIG. 1, a position display section 20 is formed on the peripheral edge of the rotor plate 15, and a reference display section 21 is further formed on the inner periphery of this position display section 20. The position display section 20 is
For example, slits drilled every 2 degrees, or
The reference display section 21 is a round hole, and the reference display section 21 is a hole drilled at intervals of 90 degrees, for example.

Furthermore, the holes bored in the rotor plate 15:
On the circumference of the 1-in display section 2o and the reference display section 21,
Light emitting elements 22a and 23a such as light emitting diodes are provided opposite each other. Furthermore, these light emitting elements 22a, 23a
On the other hand, on opposite sides of the rotor plate 15, there are light receiving elements 22b and 23b, which are an example of a rotation speed detection device.
is installed.

The light-receiving elements 22b and 23b intermittently receive the light beams from the light-emitting elements 22a and 23a that pass through the display sections 20 and 21 provided in the E]-tablet 15, and generate a position pulse P1. , reference pulse P2
As shown in FIG.
is input via the input interface circuit 26.

In addition, the ALIJ25 has a read-only memory (RO
M) 27 and a read/write memory (RAM) 28 are each connected via two pass lines.

Furthermore, a display drive circuit 30 is connected to the ALU 25, and an abnormality display device 31 such as a lamp is connected to this display drive circuit 30. Note that this abnormality display device 31 is provided on an instrument panel of a vehicle (not shown).

In this J: U-shaped configuration, when the engine is driven, the drive pulley 3 mounted on the crankshaft 1 and the timing bell wrapped around the drive pulley 3)-6a
, 6b, the camshaft 2a, via the driven pulleys 4a, 4b1 interlocked with the timing belts 6a, 6b,
2b is rotated.

At the same time, the driven pulley 5 that drives auxiliary parts such as an oil pump (not shown) is connected to the timing belt 6.
It is driven by the rotational force of a.

On the other hand, the rotating shaft 1 of the destripator 10 is
2 is rotated, and a rotor brake 15 and a rotor 17, which are mounted on the rotating shaft 12, are rotated.

When the rotor plate 15 rotates, the light emitting element 22a
, 23a are emitted from the rotor brakes 1 and 23a.
The transmitted light beam intermittently passes through the position display section 20 and the reference display section 21 provided in the hole 15.
The light is received by the light receiving elements 22b and 23b.

Then, a positive control pulse Pt and a reference pulse P2 are generated in the light receiving elements 22b and 23b, respectively, and these pulses Pi and P2 are inputted to an input interface circuit 26 provided in an electronic control unit (ECU) 24 and waveform shaped. It is processed.

Next, the positive control pulse P1 is sent to the bullet performance unit (ALU).
) 25 is counted at regular intervals, and the pass line 29
is stored in the RAM 28 as an instantaneous engine rotational speed. Further, the reference pulse P2 is
The period is measured by the ALU 25, and the engine rotation speed obtained by inverse σ from the measured period is stored in the RAM 28 via the pass line 29 as average rotation speed data.

If the tension of the timing belt 6a that transmits the rotational force to the force shaft 1-28 is insufficient, the rotational fluctuation of the force shaft left 2a increases, and the instantaneous engine rotation speed data and the average rotation speed arc A difference in rotational speed will occur.

Then, the difference between the instantaneous engine rotation speed data stored in the RAM 28 and the average engine rotation speed data is calculated by the ALU 25 in accordance with a command stored in advance in the 80M27. This value is compared with a reference value (for example, 500 ppm) to determine whether the tension of the timing belt 6a is normal or abnormal.

This state will be explained according to the flowchart shown in FIG. 5. First, when the engine is started in step S1, the instantaneous rotational speed is (
i).

Further, in step S3, the average rotational speed (11) is calculated based on the reference pulse P2 outputted from the light receiving element 23b by Lt.

Then, in step S4, the absolute value of the difference between the instantaneous rotation speed (i) and the average rotation speed (11) is determined.

Next, in step S5, it is determined whether the absolute value of the difference between the instantaneous rotation speed (i) and the average rotation speed (ii) is greater than a reference value (for example, 5QQrpm).

If it is determined that the error is large, an abnormality signal is applied to the display drive circuit 30 of the ECU 24, and the display drive circuit 30 operates an abnormality display device 31 such as a lamp. As a result, the driver is warned of the signs of abnormal tension in the timing belt 6a (step S6).

Further, if it is determined in step S5 that the absolute value of the rotational speed difference is smaller than the reference value J, step S2
Return to

By the way, in a horizontally opposed engine as shown in the figure,
Camshafts 2a and 2b have separate timing belts 6a
, 6b, there is a possibility of tension abnormality occurring in the timing belt 6b as well, but the load is higher on the side that drives auxiliary parts such as the oil pump, the timing belt 6a side in the figure. There is a high possibility that a major tension abnormality will occur, so measure only the tension of the timing belt 6a, and if a tension abnormality occurs in this timing belt 6a, readjust the tension of the opposite timing belt 6b at the same time. For example, there is no need to provide a special means for detecting tension abnormality in the timing bell 1-6b. Of course,
Even if a means for detecting the tension abnormality of the timing belt 6b is separately provided, no problem will arise.

Note that the belt tension abnormality detection device according to the present invention is not limited to the above-mentioned embodiments; for example, the rotor plate may be integrally formed with a driven pulley that drives a camshaft or an auxiliary component, or the belt tension abnormality detection device according to the present invention may be The means is not limited to an optical pulse type, but may be a magnetic pulse type, for example. In this case, it is preferable to employ a magnetic head as the rotation speed detection device.

[Effects of the Invention] As explained above, according to the present invention, a driven pulley is connected to a drive pulley connected to a crankshaft via a timing belt, a rotor plate is connected to this driven pulley, and this Position display sections arranged at equal intervals at narrow angles and reference display sections arranged at equal intervals at wider angles than the position display sections are provided on the peripheral edge of the rotor plate, Roughly speaking, a rotation speed detection device is provided oppositely on both of the display portions of the rotor plate, and this rotation speed detection device is connected to an electronic control device, and the position display portion of the rotor plate is connected to the electronic control device. The instantaneous rotational speed is calculated by counting the detection signals of the rotor plate, and the average rotational speed is calculated from the period measured based on the detection signal of the reference display section of the rotor plate, and the calculated instantaneous rotational speed and the average rotational speed are calculated. A calculation unit that compares the difference in rotation speed with a preset reference value and a display drive circuit that sends a signal to the abnormality display device when the compared rotation speed difference is large are provided. It is possible to accurately notify the driver of signs of timing belt tension abnormality, and one of the causes of engine malfunction can be effectively prevented.

Furthermore, since information on rotational speed abnormalities is obtained from the position display section and reference display section formed on one rotor plate, the structure does not become large and wiring becomes easy.

Further, in vehicles equipped with a crank angle sensor, the tension abnormality detection device according to the present invention can be used as is by simply changing the software, and can be widely applied.

[Brief explanation of the drawing]

The drawings show an embodiment of the present invention, in which Fig. 1 is a schematic diagram of a belt tension abnormality detection device, Fig. 2 is a vertical sectional view of a destroyer, Fig. 3 is a schematic diagram of a horizontally opposed engine, and Fig. 4 A block diagram of the belt tension abnormality detection device, and FIG. 5 is a flowchart of the belt tension abnormality detection device. DESCRIPTION OF SYMBOLS 1...Crankshaft 11 feet, 3...Drive pulley, 4a...Driven pulley, 6a...Timing belt, 15...Rotor plate, 20...Position display section, 21...Reference display Part, 22b, 2
3b... Rotation speed detection device, 24... Electronic control device (
ECU), 25... Arithmetic unit (ALU), 30...
Display drive circuit, 31... Abnormality display device 0 Agent Patent attorney Susumu Ito Figure 1 Figure 2

Claims (1)

[Claims] A driven pulley is connected to a drive pulley that is connected to the crankshaft via a timing belt, a rotor plate is connected to this driven pulley, and the drive pulley is connected to a drive pulley that is connected to the crankshaft. a position display section, and a reference display section arranged at equal intervals and at a wider angle than the position display section, and further a rotation speed detection device is provided on both display sections of the rotor plate. This rotational speed detection device is connected to an electronic control device, and the electronic control device counts the detection signal of the position display section of the rotor plate to calculate the instantaneous rotational speed, and also calculates the instantaneous rotational speed of the rotor plate. an arithmetic unit that calculates an average rotational speed from the period measured based on the detection signal of the reference display section of the controller, and compares the difference between the calculated instantaneous rotational speed and the average rotational speed with a preset reference value; An engine belt tension abnormality detecting device comprising: a display drive circuit that supplies a signal to an abnormality display device when the compared rotational speed difference is large.