JPH09125980A - Abnormality judgement device for parts around timing belt of internal combustion engine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To early detect and identify the occurrence of the abnormalites of parts around a timing belt by identifying the occurrence of such abnormalities when a temperature level detected with a temperature detection means exceeds a temperature level on a judgement line for temperature abnormalities in a timing belt case. SOLUTION: When an engine is operating, ECU 15 takes in the data of engine cooling water temperature, engine lubricating oil temperature, timing belt case internal temperature TB and the like, and first makes judgement as to whether or not the timing belt case internal temperature TB is acceptable, thereby making judgement as to whether or not the temperature is within an acceptable zone. When the judgement is affirmative, a calculation is made about temperature X corresponding either the engine cooling water temperature or the engine lubricating oil temperature. Then, judgement is made as to whether or not the timing belt case internal temperature TB is above the temperature X and when the temperature TB is above the temperature X, abnormalites are judged to be present. Also, judgement is made as to whether or not the integrated number of revolutions after the rise of the temperature TB over the temperature X is equal to or below the preset number A. When the number exceeds the value of A, notice is given of necessity for checking or replacing parts around a timing belt.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a device for determining an abnormality in a component around a timing belt of an internal combustion engine, which is capable of determining whether or not an abnormality (malfunction) has occurred in a component around the timing belt of the internal combustion engine.

[0002]

2. Description of the Related Art At present, a valve recess is provided at the top of a piston so that the engine will not be damaged even if the timing belt is broken. Therefore, it is disadvantageous in terms of performance and fuel efficiency. On the other hand, Japanese Utility Model Laid-Open No. 60-61449 has a detection means for detecting the disconnection of the timing belt that transmits the rotation of the crankshaft to the camshaft. The engine detects when the detection means detects the disconnection of the timing belt. We have proposed a device for emergency stop.

[0003]

However, the abnormality around the timing belt is not limited to the cutting of the timing belt. For example, even if the timing belt is not cut, if the water pump pulley malfunctions, a slip phenomenon occurs between the belt and the pulley, and the frictional heat causes the temperature belt case temperature to rise abnormally. The same applies when the idler becomes defective. However, with the conventionally proposed technology, it is not possible to detect and take measures against even abnormalities of parts around the timing belt at the stage before the timing belt is cut. An object of the present invention is to provide a device for quickly detecting and determining a component abnormality around the timing belt even when the usage condition is bad.

[0004]

The present invention to achieve the above object is as follows. Storage means for storing a predetermined relationship between the engine cooling water temperature or the engine lubricating oil temperature and the timing belt case temperature abnormality determination line;
A temperature detecting means for detecting the current temperature in the timing belt case, and a temperature on the timing belt in-temperature abnormality judging line for at least one of the current engine cooling water temperature and the engine lubricating oil temperature and the temperature detecting means. An abnormality determination device for a component around a timing belt of an internal combustion engine, comprising: an abnormality determination means for comparing the generated temperature with the latter temperature and determining that an abnormality has occurred in the component around the timing belt when the temperature of the latter exceeds the temperature of the former.

When the components around the timing belt are operating normally, the temperature inside the timing belt case is within a temperature range corresponding to the engine cooling water temperature or the engine lubricating oil temperature. However, if the idler or the water pump pulley malfunctions and slips occur between the belt and the pulley, the friction heat will cause the temperature belt case temperature to rise rapidly (engine cooling water temperature and engine lubricating oil temperature will not reach the heat capacity). The temperature rise is relatively mild due to the large temperature), and it goes out of the normal temperature range. The fact that the degree of this deviation has increased is compared with the temperature X on the timing belt case temperature abnormality determination line corresponding to the current engine cooling water temperature or engine lubricating oil temperature and the temperature TB detected by the temperature detecting means. If the degree of deviation is large (TB> X), it is determined that an abnormality has occurred in the parts around the timing belt.

[0006]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT FIG. 1 shows around an engine timing belt. As shown in FIG. 1, a crankshaft 2 and a camshaft 3 are attached to the engine body 1. A crank timing pulley 4 is attached to the crankshaft 2, and a camshaft timing pulley 5 is attached to the camshaft 3. The crank timing pulley 4 and the camshaft timing pulley 5 are connected by a timing belt 6. During this time, the water pump pulley 7, the first idler 8, and the second idler 9 are mounted. The first idler 8 works to keep the tension of the timing belt 6 constant by the auto tensioner 10. The timing belt 6 is in contact with the first and second idlers 8 and 9 and the water pump pulley 7 on the side opposite to the toothed side. The components around these timing belts are surrounded by the timing belt case 11 to prevent foreign matter, dust and the like from entering from the outside.

The timing belt case 11 is provided with a temperature sensor 12 as a temperature detecting means for detecting and outputting the temperature inside the timing belt case 11.
One temperature sensor 12 may be provided for the entire timing belt case 11, or one temperature sensor 12 may be provided near the water pump pulley 7, the first and second idlers 8, 9 as shown in FIG. Individual pieces 12, 13, 14 may be provided. The output signal TB of the temperature sensor is output from the electronic control unit (ECU, engine control computer including RAM, ROM, and CPU) 1 shown in FIG.
5 is input. The ECU 15 sends an engine cooling water temperature signal T from an engine cooling water temperature detection sensor (not shown).
W, an engine lubricating oil temperature signal TO from an engine lubricating oil temperature detection sensor (not shown), an engine rotational speed signal NE from an engine rotational speed sensor (not shown), etc. are input.

As shown in FIG. 3, the temperature TB in the timing belt case 11 is substantially proportional to the engine cooling water temperature TW and the engine lubricating oil temperature TO after the engine warm-up operation. The temperature TB in the timing belt case is within the range indicated by the diagonal lines in FIG. 3 if the operation of each component is normal, but if the water pump pulley 7 malfunctions, slippage occurs between the belt and the pulley. A phenomenon occurs and the temperature TB in the timing belt case rises abnormally. The same is true when the first and second idlers 8 and 9 have malfunctioned. This temperature belt internal temperature abnormality determination line is X. This line X is in a region having a temperature higher than the shaded area in FIG. The relationship between at least one of the engine cooling water temperature TW and the engine lubricating oil temperature TO and the timing belt case temperature abnormality determination line is determined in advance and stored in the ROM or RAM (storage means) of the ECU 15.

Next, FIG. 4 shows a control flow of the abnormality determining means for determining the occurrence of an abnormality in the parts around the timing belt and its operation. This flow itself is R of ECU15
It is stored in AM or ROM and its calculation is done by CPU
It is executed in. This flow is interrupted at predetermined time intervals. At step 101, the current engine cooling water temperature TW, engine lubricating oil temperature TO, timing belt case internal temperature TB, and engine speed NE are read.
In step 102, it is determined whether or not the current state is a region where the temperature inside the timing belt case can be determined.
That is, in order to prevent erroneous determination of TB, the determination region is set after warming up, that is, TW> TW1 and TO> TO1,
The engine speed is also N ₁ ≦ NE ≦ N ₂ for the same reason.
And If it's not in this zone, go to end and end that cycle.

Next, at step 103, the temperature X on the timing belt case temperature abnormality determination line corresponding to at least one of the current engine cooling water temperature TW and the current engine lubricating oil temperature TO is referenced using the map of FIG.
Is calculated. In step 104, the temperature detection sensor 12
(Or 13, 14), it is determined whether or not the current timing belt case temperature TB detected by (13, 14) exceeds the temperature X, and if TB ≦ X, it is considered that no abnormality has occurred, and the process proceeds to END and the cycle ends. .

If TB> X in step 104, it is determined that there is an abnormality in the operation of the parts around the timing belt. In that case, first, in step 105, the flag F
It is determined whether L is 0 or 1. If FL = 0, this cycle is TB
It means that it is the first cycle that becomes> X, and FL
= 1 means that this cycle is the second and subsequent cycles after TB> X. FL in step 105
In the case of = 0, the routine proceeds to step 106, where the engine speed from the time when TB> X is satisfied is counted and integrated (calculation of ΣNE) is started. Then, in step 107, the flag FL is set to 1. When step 105 is reached in the next cycle, FL is set to 1 in the previous cycle.
Since it has been set to step 105 to step 108
Proceed to.

In step 108, it is determined whether the integrated rotation speed ΣNE after TB> X is less than or equal to a predetermined value A, and A
If it is below, the wear of the timing belt and its surrounding parts can be ignored, and the process proceeds to the end. Informs you that Then, step 110
Then, it is determined whether or not the cumulative number of revolutions ΣNE after TB> X is equal to or less than a predetermined value B (however, B> A). If it exceeds B, the range where evacuation operation is possible, for example, 4
The fuel injection amount is reduced to the extent that the vehicle can travel at about 0 km / hr (step 111). Then step 1
12 and accumulated rotation number ΣNE since TB> X
Is less than or equal to a predetermined value C (where C> B), and C
If it is below, it is possible to respond by evacuation operation and proceed to the end, C
If it exceeds, the routine proceeds to step 113, the fuel is cut, and the engine is stopped. This prevents engine damage. Steps 109, 111, 113
If the parts around the timing belt are maintained after passing through, set FL to 0 in step A,
Resets ΣNE to 0.

FIG. 1 also shows a case where a plurality of temperature sensors 13 and 14 are provided. The parts that are likely to cause troubles when they are not used well are the water pump pulley 7, the first idler 8, and the second idler 9 (none in the case of an in-line engine) that are operating with grease lubrication. FIG.
As shown in FIG. 5, by mounting the temperature sensors 12, 13 and 14 near these components 7, 8 and 9, it is possible to determine which component has an abnormality. In this case,
In the flowchart of FIG. 3, it is assumed that TB makes a determination with respect to all the temperatures detected by the temperature sensors 12, 13, and 14, and if there is an abnormality, it also displays which of the abnormal parts is present. Is desirable.

[0014]

According to the present invention, the timing belt case internal temperature TB detected by the temperature detecting means is set to a predetermined timing belt case internal temperature abnormality judging line for at least one of the engine cooling water temperature and the engine lubricating oil temperature. It is determined that an abnormality has occurred in the parts around the timing belt when TB> X by comparing with the above temperature X. Therefore, an abnormality actually occurs in the parts around the timing belt and the temperature TB It is possible to quickly detect that the engine speed has risen, and to detect when the timing belt is not damaged, and prevent engine damage.

[Brief description of the drawings]

FIG. 1 is a front view of an abnormality determination device for components around a timing belt of an internal combustion engine according to an embodiment of the present invention with a belt case removed.

FIG. 2 is a diagram showing inputs from various sensors to an ECU connected to the apparatus of FIG.

FIG. 3 is a map showing a relationship between at least one of an engine cooling water temperature and an engine lubricating oil temperature and a timing belt case temperature abnormality determination line.

FIG. 4 is a flowchart of a control routine of abnormality determining means.

[Explanation of symbols]

 1 Engine Body 2 Crank Shaft 3 Cam Shaft 4 Crank Timing Pulley 5 Cam Shaft Timing Pulley 6 Timing Belt 7 Water Pump Pulley 8 First Idler 9 Second Idler 11 Timing Belt Case 12, 13, 14 Temperature Detector (Temperature Sensor) ) 15 ECU

Claims (1)

[Claims] 1. Storage means for storing a predetermined relationship between an engine cooling water temperature or an engine lubricating oil temperature and a timing belt case temperature abnormality determination line, and temperature detection for detecting a current temperature in the timing belt case. Means and the temperature on the timing belt case temperature abnormality determination line for at least one of the current engine cooling water temperature and engine lubricating oil temperature and the temperature detected by the temperature detecting means, and the latter temperature is An abnormality determination device for a component around a timing belt of an internal combustion engine, comprising: abnormality determination means for determining that an abnormality has occurred in a component around the timing belt when the temperature exceeds the temperature.