JPH0453549Y2 - - Google Patents

Description

[Detailed explanation of the invention] (Field of industrial application) The present invention relates to a knock detection device for a V-type engine. The present invention relates to a device for reliably detecting knocking.

(Prior Art) Knocking is a phenomenon in which the gas in the combustion chamber vibrates due to self-ignition of gas at the end of the combustion chamber, and this vibration is transmitted to the engine body, for example, the cylinder block. If this kind of knocking occurs violently, it can cause energy loss (reduction in output), shock to various parts of the engine, and even a decrease in fuel efficiency, so it is desirable to avoid it.To do this, it is necessary to accurately detect the occurrence of knocking. There is.

Further, in the case of a V-type engine, since both banks are separated, it is necessary to devise an accurate knocking detection that takes knocking vibration into consideration.

A conventional knock detection device for a V-type engine of this type is disclosed in Japanese Utility Model Application Laid-Open No. 59-106029. This device is provided with a plurality of reinforcing ribs that connect both banks of the cylinder block and a connecting rib that connects these reinforcing ribs, and a knock sensor is arranged at the end of the connecting rib that protrudes from the end surface of the cylinder block. A knock sensor is installed on the wall of a nearby cylinder block to detect knocking-specific vibrations transmitted through both ribs, that is, knocking vibrations.
Furthermore, in order to remove casting sand from the central portion between both banks after the cylinder block is cast, the connecting rib is provided close to one bank.

(Problems to be Solved by the Invention) However, in such a conventional knock detection device for a V-type engine, a knock sensor is installed at one end of a connecting rib that is close to one bank and protrudes from the end surface of the cylinder block. Because the knock sensor was installed on the wall of the cylinder block near the reinforcing rib or the connecting rib, it was possible to detect the knocking vibration that occurs in the cylinders on one side of the bank where the knock sensor was installed, but the knocking vibration on the other side The knocking vibration that occurs in the cylinders of the bank has large damping and cannot be detected accurately. Therefore, there was a problem in that knocking occurring in each cylinder could not be reliably detected with a single knock sensor.

(Purpose of the invention) Therefore, in this invention, by devising the installation form of the ribs between both banks and by limiting the mounting position of the knock sensor to an optimal location, the knocking vibration generated in all cylinders is averaged to the knock sensor. The purpose is to reliably detect knocking that occurs in each cylinder.

(Means for Solving the Problems) In order to achieve the above object, the knock detection device for a V-type engine according to the present invention has two banks arranged at a predetermined angle apart, and the cylinder bores are located at different positions between the two banks. In the knock detection device for a V-type engine, the cylinder block has a cylinder block formed with a head bolt hole for attaching a cylinder head near the cylinder bore. A plurality of extending first ribs and a plurality of second ribs connecting the first ribs and extending along the inner wall surfaces of both banks are provided, and the first rib and the second rib are provided. A knock sensor for detecting knocking vibration is provided at the connection part with the head bolt hole and on the side opposite to the side near the head bolt hole.

(Function) In the present invention, a plurality of first ribs and a first
A plurality of second ribs are provided that connect the ribs of the bank and extend along the inner wall surfaces of both banks, and the other rib is provided at the connection portion between the first rib and the second rib and is not adjacent to the head bolt hole. A knock sensor for detecting knocking vibration is provided at a side position. Therefore, the knocking vibration generated in the cylinder in one bank is transmitted from the vicinity of the head bolt hole to the other bank through the first rib with almost no attenuation, and is transmitted to the cylinder located away from the knock sensor. The knocking vibration is also transmitted through the plurality of second ribs with almost no attenuation. As a result, knocking vibrations caused by knocking in all cylinders are transmitted evenly to the joint between both ribs on the other bank side, that is, to the mounting position of the knock sensor, and knocking occurring in each cylinder is reliably detected.

(Example) Hereinafter, the present invention will be explained based on the drawings.

1 to 4 are diagrams showing an embodiment of the present invention. First, the configuration will be explained. In Figures 1 and 2, 1 is a cylinder block of a V-type engine, and cylinder block 1 has two banks 2a,
2b are arranged at a predetermined angle of separation. A plurality of cylinder bores 3 are formed at predetermined intervals in the banks 2a and 2b.
a, 3c, 3e and cylinder bore 3 of bank 2b
b, 3d, 3f are the end faces 1a of the cylinder block 1
are formed at different distances from the A plurality of head bolt holes 4 are drilled at a predetermined pitch in the cylinder block 1 near the cylinder bore 3 for attaching cylinder heads (not shown) to the cylinder block 1. Like the cylinder bore 3, the head bolt holes 4 are located between the banks 2a and 2b. are located at different locations.

Also, between banks 2a and 2b, one bank 2
Reinforcement ribs 5, which are a plurality of first ribs, extend from the vicinity of the head bolt hole 4 on the inner wall side of bank 2a toward the other bank 2a, and the reinforcing ribs 5 are connected to each other, and Connecting ribs 6, which are a plurality of second ribs extending along the cylinder block 1, are cast integrally with the cylinder block 1. Also, at the connection part between the reinforcing rib 5 and the connecting rib 6, and at the bank 2
A sensor mounting boss 7 is formed on the side of the bank 2b that is not adjacent to the head bolt hole 4 of b. A knock sensor 8 is attached to the sensor mounting boss 7, and the knock sensor 8 has a vibration frequency of 6 to 8 K, which is unique to knocking.
Detects Hz vibration, that is, knocking vibration.

Turning to FIG. 2, reference numeral 9 denotes a plurality of sand removal holes for removing casting sand after casting the cylinder block 1, and the reinforcing ribs 5 and the connecting ribs 6 represent the sand removal holes 9.
It is located to avoid In a V-type engine having a cylinder block 1, the head bolt (not shown) that fixes the cylinder head to the cylinder block 1 and the vicinity of the head bolt hole 4 have high rigidity due to its structure, and the knocking vibration generated in the cylinder in the bank 2b is caused by the head bolt hole 4. This makes it easier for it to be transmitted to the reinforcing ribs 5 from the vicinity. Further, the reinforcing rib 5 is connected to the cylinder bore 3 which is located away from the sensor mounting boss 7.
They are arranged at small intervals near e and 3f, so that knocking vibrations generated in cylinders distant from the knock sensor 8 are easily transmitted.

On the other hand, the knock sensor 8 is connected to a control unit (not shown), and determines whether knocking has occurred based on the detection signal of the knock sensor 8 of the control unit, and if knocking occurs, it retards the ignition timing, etc. Executes knocking suppression processing. Such knocking suppression by controlling the ignition timing is well known, so the details will be omitted.

Next, the effect will be explained.

When knocking occurs in each cylinder of a V-type engine, the knocking vibration is transmitted from the cylinder block 1 to the reinforcing ribs 5 and the connecting ribs 6.

Here, the reinforcing ribs 5 and the connecting ribs 6 are arranged so as to easily transmit knocking vibrations caused by the knocking of cylinders in the bank 2b and cylinders distant from the knock sensor 8, and the reinforcing ribs 5 and the connecting ribs 6 are arranged on the side of the bank 2b. Since the knock sensor 8 is attached to the connecting portion of the cylinder, knocking vibrations due to knocking of these cylinders, which could not be detected due to large damping in the past, are reliably transmitted to the knock sensor 8. Therefore, the knocking vibrations of all the cylinders are reliably transmitted to the knock sensor 8 on the average, and knocking occurring in each cylinder can be reliably detected by the single knock sensor 8. Incidentally, as shown in FIG. 3, the knock detection rate (number of knocking detections/number of knocking occurrences) of the knock sensor 8 shows a high value. In the diagram, #1 to #6 are cylinder bore 3
The cylinders 1 to 6 corresponding to cylinders a to 3f are shown, and the knock detection rate of this embodiment is shown by a solid line A. Additionally, the knocking detection rate does not reach 100% because the weak knocking vibrations and the noise vibrations generated in various parts of the V-type engine are approximately equal in frequency and level, so knocking vibrations below a predetermined value are detected as knocking. This is because the circuit constants are set to prevent this from occurring. What is indicated by the broken line B in FIG. 3 is the bank 2a shown for comparison.
This is the knock detection rate in the conventional case where the knock sensor 8 is arranged on the outer wall of the building. Therefore, as is clear from the comparison between this embodiment and the conventional example in FIG. 3, the present embodiment can uniformly detect knocking in all cylinders with much higher accuracy than the conventional one. .

Figures 4 and 5 show two different engine speeds N.
The vibration level when knocking occurs in cylinders #1 to #6 during operation is shown in comparison between this embodiment and the conventional example described above. FIG. 4 shows the case when N=2400 rpm, and FIG. 5 shows the case when N=4800 rpm. In either case, the area surrounded by a square in the figure represents the increase in vibration due to knocking, and in the case of this embodiment, which is surrounded by a solid line, the vibration due to knocking is on average higher than that of the conventional knock sensor 8.
It can be seen that this is being transmitted to In addition, the reinforcing rib 5
Since the connecting rib 6 is provided avoiding the sand removal hole 9 in the center between the banks 2a and 2b, the bank 2
A core for molding between a and 2b can be easily produced, and the number of man-hours required for sand removal work after the cylinder block 1 is cast can be reduced. This shows that there is no problem in manufacturing the cylinder block when the knocking detection accuracy is improved, and the work efficiency is good.

In this embodiment, the knock sensor 8 is installed at the position of the knock sensor mounting boss 7, but the present invention is not limited to this, and the arrangement of the first and second ribs provided between the banks 2a and 2b may be changed. Therefore, the knob sensor 8 can be installed at different positions. In short,
A plurality of first ribs extending from the vicinity of the head bolt hole of one bank to the other bank are connected to a plurality of second ribs provided along the inner walls of both banks. A knock sensor may be provided at the connecting portion located on the other bank side. Further, the V-type engine is not limited to six cylinders, and may have a different number of cylinders.

(Effects) According to the present invention, a plurality of first ribs extend from the vicinity of the head bolt hole where knocking vibration of one bank is easily transmitted toward the other bank;
A plurality of second ribs connecting the ribs of the bank and extending along the inner wall surfaces of both banks are provided, and the joint between the first rib and the second rib is adjacent to the head bolt hole. Since a knock sensor that detects knocking vibration is provided on the opposite side, the knocking vibration generated in each cylinder can be transmitted to the knock sensor in an average manner, and the knocking generated in each cylinder can be transmitted to the knock sensor by a single knock sensor. can be reliably detected.

[Brief explanation of the drawing]

1 to 5 are diagrams showing an embodiment of the knock detection device for a V-type engine according to the present invention, and FIG. 1 is a perspective view showing the configuration of the cylinder block, and FIG.
The figure is a front view showing the arrangement of the first and second ribs, Figure 3 is a graph showing the knock detection rate of the device, and Figures 4 and 5 are two types of engine rotation speed of the V-type engine. 3 is a graph showing the vibration level when knocking occurs. 1...Cylinder block, 2...Bank, 3...
...Cylinder bore, 4...Head bolt hole, 5...
Reinforcing rib (first rib), 6...Connecting rib (second rib)
rib), 8...knot sensor.

Claims (1)

[Scope of utility model registration request] A V-shaped cylinder block in which two banks are arranged at a predetermined angle apart, cylinder bores are formed at different positions between the two banks, and head bolt holes for attaching the cylinder head are formed near the cylinder bores. In the engine knock detection device, a plurality of first ribs extend from a portion near the head bolt hole of one bank toward the other bank, and the first ribs are connected to each other, and the first ribs are connected to each other, and A knock sensor for detecting knocking vibration is provided at the connection portion between the first rib and the second rib and on the side opposite to the side adjacent to the head bolt hole. A knock detection device for a V-type engine, which is characterized by: