JPS62101839A - Knocking sensor installation structure for v-type engine - Google Patents

Abstract

PURPOSE:To detect the vibration of knocking accurately by forming a connecting member, with which the upper outer walls of a plurality of cylinder blocks arranged in a V like form are connected each other, so as to install a knocking sensor at the center section of the connecting member. CONSTITUTION:An engine block 12 is integrally formed with both a plurality of cylinder blocks 6 and 8 and the upper half of a crank case 7. And a plurality of cylinders 6a-6c and 8a-8c is formed in series to each of the cylinder blocks 6 and 8, and these cylinder blocks are arranged each other into a V like form. In this constitution, the engine block 12 is formed with a connecting member 5, by which the center sections of block upper decks 13 and 14 formed on each of the cylinder blocks 6 and 8 are connected each other. And a column section 5a extending vertically is formed at the center section of the connecting member 5 so as to install a knocking sensor 1 on the top surface of the column section 5a.

Description

[Detailed description of the invention]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a knock sensor mounting structure for type II engines. 2. Description of the Related Art There is a well-known device that, when knocking occurs in an internal combustion engine, detects the vibration with a knock sensor and controls the ignition timing to prevent the knocking from continuing. When applying this device to a V-type engine, it is necessary to provide separate knock sensors for each of the two cylinder blocks arranged in a V-shape, which complicates the processing circuit for the sensor detection signal. As a result, the overall cost becomes quite high. Therefore, for example, according to Utility Model Application No. 59-106029, a plurality of first members connecting both cylinder blocks and a first
The second member that connects the members constitutes a knock transmitting means, and the knock sensor is attached directly to or near the knock transmitting means, thereby achieving a single knock sensor. Problems to be Solved by the Invention However, in the knock detection device disclosed herein, since the first member is connected to the lower portions of both cylinder blocks, the first member normally corresponds to the upper portion of the cylinder block. The vibration of one cylinder cylinder cylinder due to knocking occurring in the combustion chamber is attenuated by the time it reaches the knock sensor, making it difficult to detect the vibration. On the other hand, in the knock sensor mounting structure disclosed in Utility Model Application No. 59-196531, a rib corresponding to the first member is formed over almost the entire length between both cylinder blocks, and the knock sensor is mounted on this rib. Because
Although the aforementioned knocking vibration damping is avoided, the following problems are not solved because the rib or the first member is connected to the lower portions of both cylinder blocks. (1) The piston stroke γS generated near the bottom dead center is transmitted to the knock sensor, making detection of knocking uncertain. This hitting sound is caused by the piston's load acting on the inner wall of the cylinder (
When the point of action of the piston (nide thrust) moves to the opposite side of the piston pin near the vertical dead center, the piston changes its position within the small gap formed between the piston and the cylinder inner wall. This is caused by applying an impact to the inner wall, and due to the mounting position of the knock sensor, the knocking noise especially near the bottom dead center becomes a problem. Figure 4 is for explaining the timing of the tapping sound near the bottom dead center, and the horizontal axis is the top dead center (top dead center) of the first cylinder.
This is the crank angle with the origin at TDC). Here, 6
An example is given for a cylinder ■ type engine, and for example, as shown in the figure, the knock judgment section is from T[]C to a crank angle of 90°.
If the setting is within the range of , the bottom dead center hitting sound at J3 in the third and sixth cylinders will be detected as knocking in the first cylinder. Similarly, the bottom dead center hitting sound of the 1st and 4th cylinders is considered as knocking of the 2nd cylinder, the bottom dead center hitting sound of the 2nd and 5th cylinders is considered as the knocking of the 3rd cylinder, etc., respectively. It may be detected by the knock sensor. In order to avoid this problem, for example, it may be possible to set the knock judgment section to a range from the top dead center of each cylinder to a crank angle of 60 degrees or less, so that the knocking sound is not detected. Since knocking does not necessarily occur directly at top dead center, it is not very practical. (2) In addition to the above-mentioned piston hitting noise, noises caused by rattling and elastic deformation caused by the rotation of the crankshaft, which constantly moves its center of gravity, reach the knock sensor.
Knock detection is inhibited. (3) Knock sensors usually have a diaphragm that transmits vibrations at the mounting location and a piezoelectric element that converts the vibrations into electrical signals as their basic components. When exposed to heat, it may undergo thermal deformation or alteration.
Characteristics such as vibration frequency response and output voltage may change, resulting in abnormal operation. SUMMARY OF THE INVENTION Therefore, an object of the present invention is to provide a knock sensor mounting structure that reduces knocking vibration damping, piston and crankshaft noise, and further reduces the upper limit of temperature at the mounting position. Means for Solving the Problems It is clear that the problems of the prior art described above are caused by the fact that the first member or rib that vibrates together with the cylinder tab L is connected to the lower part of the cylinder tab. be. Therefore, in a V-type engine in which one cylinder block and another cylinder block are arranged in a V-shape, the knock sensor mounting structure of the present invention forms a connecting member that connects the upper parts of the outer walls of both cylinder blocks. The present invention is characterized in that a knock sensor is attached near the center of the connecting member. Function: In the knock sensor mounting structure of the present invention, the knock sensor is mounted on the connecting member that is connected at the upper part of both cylinder blocks, so that the knocking vibrations generated within the combustion chamber can be transferred to the cylinder block without greatly reducing the capital.

[It is transmitted through the cock and detected by the knock sensor via the connecting member. In addition, since the connecting member is connected only by the 1:1 cylinder tab and a part of the cylinder tab, noise from the bottom of the cylinder and heat from the combustion chamber are transmitted to the knock sensor.
[ru. Embodiments Hereinafter, preferred embodiments of the present invention will be explained based on the drawings. Referring to FIG. 3, a schematic configuration of a knock detection device to which the present invention is applied is shown. The knocking determination circuit 3 determines whether or not there is a knocking state, and based on this result,
Ignition timing is controlled in a known ignition timing control circuit 4. An embodiment of the present invention is shown in FIGS. 1 and 2,
12 is an engine block. engine block 12
The first cylinder block 6 and the second cylinder block 8
This is achieved by integrally molding the upper half portion 7 of the crankcase, and in this embodiment, it is used for a type 6 cylinder. Three cylinders 6a, 6b, 6C are formed in series in the first cylinder block 6, while three cylinders 8a, 8b18c are formed in the second cylinder block 8, and both cylinder blocks 6 and 8, that is, the cylinders 6a~6C and 8゛a~8C are V
It is arranged to form a mold. The engine block 12 includes both cylinder blocks 6.8
Block upper deck formed on the top of 13.14
A connecting member 5 is formed to connect the central portions of each. The connection between the connecting member 5 and the cylinder block 6.8 is preferably a rigid connection, for example by monolithic casting, so that vibrations transmitted from the cylinder block to the connecting member are not attenuated. (A cylindrical portion 5a extending vertically in FIG. 2 is formed approximately at the center of the connecting portion 445, and a knock sensor 1 is placed on the top end surface of the cylindrical portion 5a. .In the figure, 25 is the combustion chamber, 9 is the water jacket,
10 indicates a piston, and 11 indicates a connecting rod. In the above configuration, the cylinder tab 6.8
The knocking that occurs in the combustion chamber 25 of each cylinder forces the cylinder block 6.8 to vibrate. This vibration is transmitted through the highly rigid block upper deck 13 and is further detected by the knock sensor 1 via the connecting member 5 that is rigidly connected to the block upper deck 13. In the mounting structure of the present invention, the connecting member 5 is connected to the cylinder butt 1.
Since it is connected only by the cylinder block 6.8 and the block upper deck 13.14 formed at its upper part, the piston hitting sound at the bottom dead center that occurs at the lower part of the cylinder block 6.8,
Alternatively, noise generated by a crankshaft (not shown) or the like is less likely to be transmitted to the knock sensor 1. In addition, since there is little heat transfer from the knock upper deck 13.14 to the connecting member 5, the thermal load on the knock sensor 1 is small.
Does not adversely affect detection characteristics. FIG. 5 and FIG. 6 show another embodiment of the present invention, in which substantially the same components as in the previous embodiment are not given the same reference numerals, and some explanations thereof are omitted. . The difference in this embodiment is that instead of providing only a connecting member 5, a connecting member 15 that connects parts of the block upper deck 13, 14 that substantially correspond to the cylinders 6a, 8a, and
a connecting member 16 that connects a portion approximately corresponding to c,
The present invention is characterized in that a reinforcing member 26 is formed to connect these three connecting members approximately at the center. By doing so, there is no concern that knocking vibrations generated in the cylinders 6a, 6c, 8a, 8C located relatively far from the knock sensor 1 will be attenuated by the cylinder tabs 1, 8.・Generally, in V-type engines,! '! As shown in FIG. 7, the intake manifold 18 and the nerge tank 17 are often attached to a cylinder head 20.20 provided at the top of the cylinder block 6.8. In addition, the exhaust manifold (not shown) is also often provided above the cylinder cylinder [1], and therefore, as explained in the previous embodiments, the connecting member 5
If it is difficult to attach the knock sensor 1 to the upper side, it is possible to attach it to the lower side of the connecting member 5, as shown in the figure. Note that 19 indicates a head cover provided on the upper part of the cylinder head 20. Further, the shape of the connecting member 5 may be any shape as long as its rigidity is high and the knocking vibration from the cylinder tab 1] is less attenuated. As shown in Figure (e), rectangles, circles, ellipses, triangles, or regular shapes can be considered. In order to further reduce vibration damping, for example, as shown in FIG. 9(f), a protrusion 51 is provided at the bottom of the rectangular connecting member 5' to increase its rigidity, or as shown in FIG. Like,
A rib 53 may be provided at the lower part of the connecting member 5'' having a protrusion 52 at the lower part, spaced apart from the connecting member 5'' and connected between both cylinder blocks to increase the apparent rigidity. Here, the connection member 5'' and the rib 53 are separated from each other by the rib 53 connected to the cylinder tab 1.
This is to prevent the knock sensor from being affected by heat. In order to increase the apparent rigidity of the connecting member, in addition to the above measures, for example, as shown in FIGS. 11 and 12,
Block upper deck 13 of connecting member 5.15.16
．． A radius 23 may be provided at the connection portion with 14. In addition, the connecting member 5 and the block 1 cock upper deck 13.14
For example, as shown in FIG. 8, flanges 5C may be formed at both ends of the connecting member 5, and the flanges 5C1, 5C may be connected to the holes 5d without integral casting as described above.
It may also be fastened to a female screw (not shown) installed on the block upper deck 13, 14 with a bolt (not shown) through the screw. In the same figure, 5b indicates a female screw for screwing the knock sensor. Although the above embodiments have been particularly described for a 6-cylinder ■type engine, the mounting structure of the present invention is not limited to this, and is of course applicable to ■type engines with other numbers of cylinders. Effects of the Invention In the knock sensor mounting structure of the present invention, a connecting member is formed that connects only the upper portions of both cylinder blocks, and the knock sensor is attached to this connecting member.
Compared to the prior art, the following special effects occur. (1) Imaging of knocking occurring in the combustion chamber corresponding to the upper part of the cylinder block becomes difficult to attenuate before reaching the knock sensor. (2) Noises such as piston hitting sounds generated at the bottom of the cylinder cylinder are less likely to be transmitted to the knock sensor. (3) As shown in Fig. 13, a 7-shaped space 30 is formed between both cylinder tabs]-1 and 6.8, and this is where the YX7 harness 31, vibe 32, or ignition coil or starter motor (not shown), etc. Auxiliary equipment can be installed. Furthermore, as a ripple effect, the character 7 space becomes open in the direction of cylinder arrangement, making it difficult for water to accumulate.

[Brief explanation of drawings]

FIG. 1 is a plan view showing an embodiment of the present invention, FIG. 2 is a sectional view taken along the line ■-■ in FIG. 1, and FIG. 3 is a basic configuration of a knock detection device to which the present invention is applied. FIG. 4 is an explanatory diagram for explaining the timing of the bottom dead center screws 1 to 1, FIG. 5 is a plan view showing another embodiment of the present invention, and FIG. is a Vl-Vl sectional view in FIG. 5, FIG. 7 is a partially cutaway side view showing still another embodiment of the present invention, FIG. 8 is a plan view and side view of the connecting member, and FIG. Diagram (a)
9 to 9([) are sectional views of a connecting member, FIG. 10 is a sectional view of a connecting member etc. showing another embodiment of the present invention, and FIGS. 11 and 12 are further sectional views of a connecting member, etc. of the present invention. FIG. 13 is a plan view showing another embodiment, and a cross-sectional view showing the ripple effect of the present invention. 1...knock sensor, 2...V-type engine, 3.
... Knocking determination circuit, 4... Ignition timing control circuit, 5.5', 5'', 15.16... Connection member, 5a.
...Cylindrical part, 6.8...Cylinder block, 6a, 6b, 6c, 8a, 8b, 8c...Cylinder, 9.
...Water jacket, 10...Piston, 11.
...] Engine block, 12.
14...Block upper deck, 26...Reinforcement member, 53...Rib. Figure 1 Figure 2 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 (Q) (bl
(C) Figure 10 Figure 11 Figure 12

Claims (1)

[Claims] V between one cylinder block and another cylinder block
A V-type engine arranged in a mold, characterized in that a connecting member is formed to connect the upper parts of the outer walls of both cylinder blocks, and a knock sensor is attached near the center of the connecting member. Knock sensor mounting structure.