JPS626131A - Detector for combustion pressure of rotary-piston engine - Google Patents

Abstract

PURPOSE:To reduce the cost of the titled detector by providing a vacant chamber in an intermediate housing and providing a combustion pressure sensor therein and communicating the high-pressure operational chambers at both sides in an alternative way and enabling to detect the combustion pressures of both the operational chambers with one sensor. CONSTITUTION:In a rotary piston engine 1 with multiple cylinders, the vacant chamber 10 is formed in the intermediate housing 4 dividing the two high- pressure operational chambers. The vacant chamber 10 is communicated with the high-pressure operational chambers at both sides of the front side and the rear side by paths 11 and 12. Then, the combustion pressure sensor 15 is provided in the vacant chamber 10 and a valve disc 13 is provided therein and can be communicated with either of the high-pressure operational chambers at both sides. Since the phase of a combustion pressure variation in the high- pressure operational chambers at both sides is different mutually, the pressures of the two high-pressure operational chambers can be detected even with one combustion pressure sensor by operating the valve disc 13 properly.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a combustion pressure detection device for a low-return piston engine.

(Prior art) Recently, electronic ignition timing control devices that use a full transistor type non-contact electronic advance device to control the ignition timing of an engine and control the ignition timing using a microcomputer have been widely adopted. has been done. When such an electronic ignition timing control device is employed, control is generally performed to obtain the optimum ignition timing based on engine speed, intake negative pressure, cooling water temperature, etc.

However, such a control system requires a plurality of detected values as described above as control parameters serving as a reference for obtaining the optimum ignition timing, and further calculates a predetermined 0 ignition timing control signal from these values7.

A complex function generator is also required. Moreover, it is not a system that directly detects the combustion state of the engine itself.
Since it is necessary to determine the optimal combustion state and the corresponding ignition timing in advance in relation to the above control parameters, highly accurate ignition timing cannot be determined without making the control system itself considerably complicated. The disadvantage is that it cannot be controlled.

Conventionally, for example, in reciprocating engines, etc., in view of the above circumstances, the combustion pressure itself in the cylinder is directly picked up by a pressure sensor, and the peak value of the combustion pressure is measured at the peak angle of the TDC signal detected by the crank angle detection means. A control system has been adopted which obtains the optimum ignition timing in response to the above (for example, see Japanese Patent Application Laid-Open No. 53-41648).

In other words, this control system monitors the engine cylinder combustion pressure as a detected data value, and performs negative feedback control on the ignition advance value so that the peak value of the combustion pressure is at the optimal position in relation to the crank angle. Since the system uses only a few control parameters and does not require a complicated function generator, the control system can also be configured with a normal negative feedback loop, making the configuration simple and inexpensive. become. Furthermore, since the combustion pressure itself within the cylinder is directly detected to obtain the optimum combustion state, there are many advantages such as higher control accuracy.

However, when actually installing such an ignition timing control system based on combustion pressure detection on an engine, the pressure sensors described above are required at least as many as the number of cylinders. It was necessary to install a

If we consider the case where the ignition timing control system using combustion pressure detection as described above is further applied to a multi-cylinder rotary piston engine, in this case too, the combustion pressure for each working chamber in each rotor housing is detected. Similarly, pressure sensors must be installed in each rotor housing, and cost reduction in this respect has been an issue.

(Object of the Invention) The present invention particularly provides a multi-cylinder rotary piston engine in which each rotor housing is structurally adjacent to each other on the left and right through an intermediate housing, and the phases of combustion pressure changes in each of the working chambers are mutually mutual. Focusing on different things, we have developed a rotary piston that uses a single pressure sensor to alternately detect the combustion pressure in both working chambers, thereby reducing the number of installed pressure sensors and contributing to lower costs. The object of the present invention is to provide a combustion pressure detection device for an engine.

(Means for Achieving the Object) In order to achieve the above object, the combustion pressure detection device for a rotary piston engine of the present invention provides a combustion pressure detection device for a multi-cylinder rotary piston engine. A cavity is formed that communicates with each working chamber in each of the rotor housings, and a combustion pressure sensor is arranged at a predetermined position within the cavity, and the high pressure side working chamber on the front side or rear side is connected to the combustion pressure sensor. Valve means is provided for selectively allowing communication.

(Function) According to the above means, a cavity communicating with each working chamber is formed in the intermediate housing portion of a multi-cylinder rotary piston engine, and both of the working chambers are connected to this cavity through the valve means. Since the combustion pressure from either one of the high-pressure side is selectively introduced, the combustion pressures of both working chambers can be detected together by the single pressure sensor mentioned above, which reduces the number of pressure sensors. becomes possible.

(Embodiment) FIGS. 1 to 4 show an embodiment in which the present invention is applied to a two-cylinder rotary piston engine.

First, in FIGS. 1 and 2, the reference numeral 1 indicates a two-cylinder rotary piston engine. It is composed of a rotor housing 2 and a rear rotor housing 3. A rotor 9 is rotatably fitted into each of the rotor housings 2 and 3 via apex seals 9a to 9c, as shown in FIG. The side housing is now joined. and,
In the joined state, the rotor 9 forms three working chambers 58 to 5c inside each rotor housing 2.3. These three working chambers 5a to 5c are configured to sequentially change their positions in a 360° rotational direction according to the rotation of each rotor 9.

On the other hand, an intake boat 6 and an exhaust boat 8 are provided on each intermediate housing side wall portion and each peripheral wall portion of each of the rotor housings 2.3, respectively,
Each of the working chambers 53 is displaced in accordance with the rotation of the rotor 9.
~5C are communicated at a predetermined position corresponding to each other. Further, reference numerals 16 and I8 denote trailing side and leading side plug holes respectively provided in the peripheral wall front sides 7a and 7b of each of the rotor housings 2.3.

On the other hand, reference numeral IO denotes an empty chamber with a predetermined volume located above the peripheral wall of the intermediate housing 4, and this empty chamber IO is connected to the working chamber in the front rotor housing 2 through a passage 11. (combustion chamber) and, via the passage 12, to the working chamber (combustion chamber) in the rear rotor housing 3, respectively. In the central part of the interior, each of the passages 11.1 and 11.
A valve body 13 (corresponding to the valve means in the claims) is fitted so as to be movable in two directions, and this valve body 13 controls the pressure inside each working chamber on either the front side or the rear side. is higher than the pressure on the other side (when the pressure in the high-pressure side working chamber becomes higher, the combustion pressure in the high-pressure side working chamber is moved to the other side by the pressure in the high-pressure side working chamber, closing the passage on the other side and reducing the combustion pressure in the high-pressure side working chamber into the above-mentioned cavity IO). On the other hand, reference numeral 15 is a pressure sensor 15 installed in the cavity IO, which detects the combustion pressure in the high-pressure side working chamber introduced into the cavity 10 and controls the ignition timing by using the detected output. manually using an external controller (not shown).

Therefore, according to the above configuration, the valve body 1 in the empty chamber 10
3, the passage closure state is switched according to changes in the pressure state of each working chamber on the front side or the rear side, and the empty chamber l is alternately switched.
The combustion pressure in each of the working chambers will be introduced into O.

Therefore, the pressure sensor 15 only detects each combustion pressure introduced into the cavity 10 each time, and although it has a single configuration, it can detect the combustion pressures of both working chambers together. .

FIG. 4 shows a time chart of the operation during this period in relation to the crank angle. That is, within the range of the crank angle detection signal (TDC signal) from 0° to 1080°1, the combustion pressure F in each of the front and rear working chambers,
R is mutual! 80° and 80 are changed as shown in the figure. Then, when the change becomes higher than the level indicated by the dashed line A in the figure, a pressure difference is generated between the two working chambers, and the valve element I3 is operated using the level A as a threshold.
The pressure sensor 15 detects the combustion pressure in the high pressure side working chamber.

Here, the signals necessary for controlling the ignition timing of the engine are from the TDC signal position pressure P1 to the maximum combustion pressure P in FIG.
As shown in the figure, it is only necessary to set the combustion end position (for example, the position of the leave-in apex seal in a rotor attitude of 90° ATDC) from the position just before the TDC signal is generated, and this setting position is sufficient. Combustion pressure in both working chambers can be detected.

(Effects of the Invention) As is clear from the above description, the combustion pressure detection device for a rotary piston engine according to the present invention is provided in a multi-cylinder rotary piston engine. A combustion pressure sensor is arranged at a predetermined position within the cavity, and the high-pressure side working chamber on the front side or the rear side is selectively connected to the combustion pressure sensor. The invention is characterized in that it is provided with valve means for communicating with the.

Therefore, according to the present invention, a cavity communicating with each working chamber is formed in the intermediate housing portion of a multi-cylinder rotary piston engine, and either one of the above-mentioned working chambers is inserted into this cavity via a valve means. Since the combustion pressure on the high-pressure side of the combustion chamber is selectively introduced, the combustion pressures of both working chambers can be detected together with the single pressure sensor mentioned above, making it possible to reduce the number of pressure sensors. becomes. Therefore, costs can be further reduced compared to the conventional case where a pressure sensor is installed for each rotor housing.

[Brief explanation of drawings]

Fig. 1 is a perspective view of a combustion pressure detection device for a rotary piston engine according to an embodiment of the present invention, Fig. 2 is a cross-sectional view of the device, and Fig. 3 shows the installation position of the pressure sensor with respect to the rotor housing. The side view shown in FIG. 4 is a time chart showing the relationship between the crank angle period of the above device and the combustion pressure change in the working chamber in each rotor housing. l...Rotary piston engine 2...Front rotor housing 3...Rear rotor housing 4...Intermediate housing IO...
...Vacancy 13...Valve body! 5...Pressure sensor gauge...Rotary vis 1~ Engine...Front side rotor housing...Rear side rotor housing---Intermediate housing 9...Vacancy 3--・・Valve body・・Pressure sensor

Claims (1)

[Claims] 1. In a multi-cylinder rotary piston engine, a cavity is formed in the intermediate housing portion that communicates with each working chamber in each of the front and rear rotor housings, and a combustion pressure sensor is placed at a predetermined position within the cavity. A combustion pressure detection device for a rotary piston engine, further comprising valve means for selectively communicating the front or rear high-pressure working chamber with the combustion pressure sensor.